NOVEL FORMULATIONS

FIELD OF THE INVENTION

The present invention relates to a novel moisturizing and barrier repair lip protectant composition comprising high levels of glycerin.

BACKGROUND OF THE INVENTION

Unprotected skin is susceptible to dehydration and becoming irritated from exposure to the elements. This is especially true for the lips, which have been found to be even more vulnerable to water loss than typical skin. In this regard, the lips have a thinner stratum comeum and also contain lesser amounts of lipids than skin on other parts of the body. When the lipid barrier is depleted or is inadequate, the lips dry out becoming irritated and prone to cracking. Lips also contain less melanin than other areas of skin, and thus are at risk of sunburn and UV damage. Accordingly, effective lip protectant compositions are highly desirable.

Many products have been introduced into the market to keep the lips in a moisturized and smooth condition, and protect them from damage. These products typically contain waxes and/or oils that mitigate the amount of moisture that is lost, known as trans-epidermal water loss. Some products may additionally contain emollients, humectants and healing agents.

A conventional lipstick includes five basic components: waxes, emollients, functional ingredients, stabilizers and colorants. Waxes and emollients tend to make up the base to which the other non-aqueous ingredients are added. A lipstick base, as such, tends to be anhydrous and simply minimizes the amount of trans-epidermal water loss, rather than replace any lost moisture.

Moisturizing compositions are typically oil-in-water emulsions and usually contain thickeners and/or conventional emulsifiers to stabilize the emulsion. Such compositions have a relatively high water content and so are able to replace moisture lost from the stratum corneum. They also typically contain one or more humectants to help retain moisture. However, while moisturizing compositions temporarily decrease visible scaling and roughness of the skin, they may offer little improvement to the integrity of the stratum comeum barrier. In fact, common moisturizing compositions which contain conventional emulsifiers can actually cause disruptions to the barrier function of the skin. Thus, a composition with a high water content may suggest that the product provides good moisturization, but it will not necessarily maintain, protect or restore the barrier function of the skin.

Accordingly, an effective topical composition that will maintain, protect and restore good barrier function to the lips is needed.

U. S. Patent No. 5,643,899, Elias et al, discloses compositions directed specifically to the treatment of epidermal barrier disorders such as hyperproliferative cutaneous diseases, papulosquamous diseases, and eczematous diseases. The disclosed compositions contain various combinations of essential lipids that include cholesterol and a ceramide, particularly acylceramide. The compositions while described for repair of the epidermal barrier function do not discuss application to the lips.

U. S. Patent No. 5,508,034, Bernstein et al, discloses compositions containing various lipids naturally found in the stratum comeum as essential components for the treatment of dry skin disorders. These compositions must contain a fatty acid, cholesterol, and a phospholipid or a glycolipid. The compositions while described for repair of the epidermal barrier function do not discuss application to the lips. U. S. Patent No. 6,663,853, Singh, discloses compositions as lip care moisturizing products which comprise fatty acid esters, a wax, an emulsifier and 1.0% unilamellar liposomes in a water-in-oil emulsion. The liposomes contain a mixture of water and glycerin. The emulsions are stated to contain squalane and panthenol. WO 2012/104604 describes a blend for use in personal care compositions, which comprises at least one dialkyl amphiphilic component and at least one ester of a branched fatty acid and branched fatty alcohol. The blend may be used as the oil phase of an oil-in- water emulsion composition. The blend may further comprise a fatty acid and a fatty alcohol. Blends prepared in accordance with WO 2012/104604 are commercially available from Croda International PLC as DuraQuench™ blends. For example, DuraQuench™ IQ comprises potassium cetyl phosphate, isostearyl isostearate, behenic acid, cetyl alcohol and cetyl behenate. DuraQuench™ IQ SA comprises potassium cetyl phosphate, isostearyl isostearate, stearic acid, cetyl alcohol and cetyl stearate. The DuraQuench™ blends are adapted for use in personal care compositions and provide moisturization to the skin by forming a layer on the skin's surface and regulating water loss. See also Pennick et al, Intl J Cos Sci, 34, P 567-574 (2012). Accordingly, an object of the present invention is to provide a topical composition that is effective in moisturizing and minimizing trans-epidermal water loss, while also protecting and repairing the barrier function of the lips. A further object of the present invention is to provide a topical composition which is convenient, easily applied to the lips and cosmetically elegant.

SUMMARY OF THE INVENTION

One embodiment of the disclosure is a topical oil-in-water emulsion composition comprising:

(a) a discontinuous oil phase;

(b) a continuous aqueous phase comprising water and glycerin, wherein the glycerin is present in an amount greater than about 12% by weight, based on the total weight of the composition;

(c) a thickening agent; and

(d) at least one lamellar membrane structure comprising (i) a dialkyl amphiphilic

component and (ii) an ester of a branched fatty acid and a branched fatty alcohol; and

wherein the composition is a lip protectant composition. In one embodiment, the glycerin in the aqueous phase is present in an amount from about 12% to about 40% by weight, based on the total weight of the composition. In another embodiment, the glycerin in the aqueous phase is present in an amount from about 20% to about 30% by weight, based on the total weight of the composition. In yet another embodiment, the glycerin in the aqueous phase is present in an amount from about 20% to about 25% by weight, based on the total weight of the composition.

Another embodiment of the disclosure is a method for moisturizing, and protecting, repairing, or restoring the skin lipid barrier of the lips of a mammal, the method comprising applying to the lips of the mammal in need thereof a therapeutically effective amount of a topical oil-in-water emulsion composition comprising:

(a) a discontinuous oil phase;

(b) a continuous aqueous phase comprising water and glycerin, wherein the glycerin is present in an amount greater than about 12% by weight, based on the total weight of the composition;

(c) a thickening agent; and

(d) at least one lamellar membrane structure comprising (i) a dialkyl amphiphilic

component and (ii) an ester of a branched fatty acid and a branched fatty alcohol; and wherein the composition is a lip protectant composition.

In one embodiment, the glycerin in the aqueous phase is present in an amount from about 12% to about 40% by weight, based on the total weight of the composition. In another embodiment, the glycerin in the aqueous phase is present in an amount from about 20% to about 30% by weight, based on the total weight of the composition. In yet another embodiment, the glycerin in the aqueous phase is present in an amount from about 20% to about 25% by weight, based on the total weight of the composition. Another embodiment of the disclosure is a method of protecting the lips of a mammal with broad spectrum protection of a UVA and UVB sunscreen, and enriched in UVA protection, the method comprising applying to the lips of the mammal in need thereof an effective amount of a topical oil-in-water emulsion composition comprising:

(a) a discontinuous oil phase;

(b) a continuous aqueous phase comprising water and glycerin, wherein the glycerin is present in an amount greater than about 12% by weight, based on the total weight of the composition;

(c) a thickening agent;

(d) at least one lamellar membrane structure comprising (i) a dialkyl amphiphilic

component and (ii) an ester of a branched fatty acid and a branched fatty alcohol; and

(e) at least one UVA sunscreen and at least one UVB sunscreen; and wherein the

UVA: SPF protection is about 1 : 1 ; and

wherein the composition is a lip protectant composition.

In one embodiment, the glycerin in the aqueous phase is present in an amount from about 12% to about 40% by weight, based on the total weight of the composition. In another embodiment, the glycerin in the aqueous phase is present in an amount from about 20% to about 30% by weight, based on the total weight of the composition. In yet another embodiment, the glycerin in the aqueous phase is present in an amount from about 20% to about 25% by weight, based on the total weight of the composition.

In one embodiment, the 1 : 1 protection ratio helps to protect against UVA induced photodegradation of pheomelanin. In one embodiment, the UVA sunscreen is

Avobenzone. In another embodiment, the UVB sunscreen is Ethylhexyl Salicylate

(Octisalate). In yet another embodiment, the composition further comprises a similiter stabilizer. In a further embodiment, the sunfilter stabilizer is Diethylhexyl Syringylidene Malonate. Another embodiment of the disclosure is a method of protecting the lips of a mammal against reactivation of herpes simplex virus, the method comprising applying to the lips of the mammal in need thereof an effective amount of a topical oil-in-water emulsion composition comprising:

(a) a discontinuous oil phase;

(b) a continuous aqueous phase comprising water and glycerin, wherein the glycerin is present in an amount greater than about 12% by weight, based on the total weight of the composition;

(c) a thickening agent; and

(d) at least one lamellar membrane structure comprising (i) a dialkyl amphiphilic component and (ii) an ester of a branched fatty acid and a branched fatty alcohol; and

(e) at least one UVA sunscreen and at least one UVB sunscreen; and wherein the UVA/SPF protection is about 1 : 1 ; and

wherein the composition is a lip protectant composition.

Yet another embodiment of the disclosure is a method of protecting the lips of a mammal against a reoccurrence of cold sores, the method comprising applying to the lips of the mammal in need thereof an effective amount of a topical oil-in-water emulsion composition comprising:

(a) a discontinuous oil phase;

(b) a continuous aqueous phase comprising water and glycerin, wherein the glycerin is present in an amount greater than about 12% by weight, based on the total weight of the composition;

(c) a thickening agent; and

(d) at least one lamellar membrane structure comprising (i) a dialkyl amphiphilic component and (ii) an ester of a branched fatty acid and a branched fatty alcohol;

(e) at least one UVA sunscreen and at least one UVB sunscreen; and wherein the UVA/SPF protection is about 1 : 1 ; and

wherein the composition is a lip protectant composition.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 illustrates key physical differences between an oil in water emulsion that can form a lamellar structure (A) and a liposome (B). DETAILED DESCRIPTION OF THE INVENTION

In one embodiment, the invention provides a topical oil-in-water emulsion composition comprising:

(a) a discontinuous oil phase;

(b) a continuous aqueous phase comprising water and glycerin, wherein the glycerin is present in an amount greater than about 12% by weight, based on the total weight of the composition;

(c) a thickening agent; and

(d) at least one lamellar membrane structure comprising (i) a dialkyl amphiphilic

component and (ii) an ester of a branched fatty acid and a branched fatty alcohol; and

wherein the composition is a lip protectant composition.

In one embodiment, the glycerin in the aqueous phase is present in an amount from about 12% to about 40% by weight, based on the total weight of the composition. In another embodiment, the glycerin in the aqueous phase is present in an amount from about 20% to about 30% by weight, based on the total weight of the composition. In yet another embodiment, the glycerin in the aqueous phase is present in an amount from about 20% to about 25% by weight, based on the total weight of the composition.

In one embodiment, the composition is a lipstick. In another embodiment, the composition is a lip balm. In yet another embodiment, the composition is a stick lip balm. In a further embodiment, the composition is a lip cream. Oil phase

The compositions of this disclosure comprise a discontinuous oil phase. The discontinuous oil phase is dispersed throughout the continuous aqueous phase.

In an embodiment, the discontinuous oil phase comprises at least one oil and/or fat. In one embodiment, the oil and/or fat is a mixture of two or more oils and/or fats.

Exemplary oils and fats include, but are not limited to, fatty acids, a source of fatty acids, fatty alcohols, esters, esters of glycerin (including mono-, di- and tri-esters), waxes, sterols, hydrocarbons, essential oils, vegetable oils and edible oils, and mixtures thereof.

Exemplary fatty acids include, but are not limited to, isostearic acid, linoleic acid, linolenic acid, oleic acid, myristic acid, ricinoleic acid, columbinic acid, arachidic acid, arachidonic acid, lignoceric acid, nervonic acid, eicosapentanoic acid, palmitic acid, stearic acid and behenic acid, and mixtures thereof.

The fatty acid can be introduced into the present compositions from a variety of sources. In an embodiment, the fatty acid is provided in the composition as an oil or wax.

Examples of oils or waxes useful in this regard include, but are not limited to, rice bran oil or rice bran wax, flaxseed oil, hempseed oil, pumpkin seed oil, canola oil, soybean oil, wheat germ oil, olive oil, grapeseed oil, borage oil, evening primrose oil, black currant seed oil, chestnut oil, corn oil, safflower oil, sunflower oil, sunflower seed oil, cottonseed oil, peanut oil, sesame oil and olus (vegetable) oil, including hydrogenated versions, and mixtures thereof.

Rice bran oil is also known as Oryza Sativa bran oil, and rice bran wax is also known as Oryza Sativa Cera. Rice bran oil has a composition similar to peanut oil, with 38% monounsaturated, 37% polyunsaturated and 25% saturated fatty acids. Rice bran wax is the vegetable wax extracted from the bran oil of rice. It contains C16-C30 fatty acids.

In one embodiment, the source of fatty acids is shea butter, also known as Butyrospermum parkii. Shea butter, which has been chemically treated, comprises five principal fatty acids, namely palmitic acid, stearic acid, oleic acid, linoleic acid and arachidic acid. Shea butter also comprises phytosterols.

In another embodiment the oil or wax is suitably selected from flaxseed oil, hempseed oil, pumpkin seed oil, canola oil, soybean oil, wheat germ oil, olive oil, grapeseed oil, borage oil, evening primrose oil, black currant seed oil, chestnut oil, com oil, safflower oil, sunflower oil, sunflower seed oil, cottonseed oil, peanut oil, sesame oil and olus

(vegetable) oil, and mixtures thereof.

In an embodiment, the source of fatty acids is olus (vegetable) oil, olive oil or rice bran oil. In another embodiment, the source of fatty acids is rice bran oil, or a mixture of rice bran oil and rice bran wax.

Exemplary fatty alcohols include, but are not limited to, behenyl alcohol, isostearyl alcohol, caprylyl alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, lanolin alcohol, arachidyl alcohol, oleyl alcohol, palm alcohol, isocetyl alcohol, cetyl alcohol, stearyl alcohol and cetearyl alcohol, and mixtures thereof. In one embodiment, the fatty alcohol is behenyl alcohol. Exemplary esters include, but are not limited to, coco-caprylate/caprate, diethyl sebacate, diisopropyl adipate, diisopropyl dilinoleate, ethyl oleate, ethylhexyl hydroxystearate, glycol distearate, glycol stearate, hydroxy octacosanyl hydroxystearate, isopropyl isostearate, isostearyl isostearate, isopropyl myristate, isopropyl palmitate, isopropyl stearate, methyl glucose sesquistearate, methyl laurate, methyl salicylate, methyl stearate, myristyl lactate, octyl salicylate, oleyl oleate, PPG-20 methyl glucose ether distearate, propylene glycol diacetate, propylene glycol dicaprylate, propylene glycol monolaurate, propylene glycol monopalmitostearate, propylene glycol ricinoleate and sucrose distearate, and mixtures thereof.

Exemplary esters of glycerin include, but are not limited to, caprylic/capric triglycerides, caprylic/capric/succinic triglyceride, cocoglycerides, glyceryl citrate, glyceryl isostearate, glyceryl laurate, glyceryl monostearate, glyceryl oleate, glyceryl palmitate, glyceryl ricinoleate, glyceryl stearate, mono and diglyceride, PEG-12 glyceryl laurate, PEG-120 glyceryl stearate, polyglyceryl-3 oleate, polyoxyl glyceryl stearate, tallow glycerides and medium chain triglycerides, and mixtures thereof.

In one embodiment, the ester of glycerin is a mono-, di- or triglyceride, such as caprylic/capric triglyceride. In one embodiment, the triglycerides are isolated from palm oil.

Waxes typically serve as a structurant for stick lip balms permitting the stick to be extended and retracted in use while maintaining the stick form. Suitable waxes for stick compositions and other embodiments of the invention include animal waxes, plant waxes, mineral waxes, silicone waxes, synthetic waxes and petroleum waxes. Exemplary waxes include, but are not limited to, rice bran wax, camauba wax, paraffin wax, white wax, candelilla wax, beeswax, jojoba wax, ozokerite and a ceramide, and mixtures thereof.

In an embodiment, the wax is a wax is a spingolipid or a spingolipid mimic. Ceramides are a family of waxy lipid molecules composed of sphingosine and a fatty acid. They contain an acyl linkage and the chain length of the most abundant chain is C24-C26 with a small fraction having an acyl chain length of C16-C 18. Ceramides are found extensively in the stratum comeum. Ceramides are commercially available from major chemical suppliers such as Evonik or Sigma Chemical Company, St. Louis, Mo., U. S.A.

Exemplary ceramides useful in the present compositions include, but are not limited to, ceramide-1 , -2, -3, -4, -5, -6 or -7, and mixtures thereof. Other ceramides known to those of skill in the art as useful in topical compositions are further contemplated as useful in the present compositions, such as those described in The Merck Index, Thirteenth Edition, Budavari et al, Eds., Merck & Co., Inc., Rahway, N.J. (2001); the CTFA (Cosmetic, Toiletry, and Fragrance Association) International Cosmetic Ingredient Dictionary and Handbook, Tenth Edition (2004); and the "Inactive Ingredient Guide", U. S. Food and Drug Administration (FDA) Center for Drug Evaluation and Research (CDER) Office of

Management, January 1996, the contents of which are hereby incorporated by reference in their entirety.

In one embodiment, the ceramide is ceramide-3.

Ceramides, acylceramides and glucosylceramides are all members of the "sphingoid" or "spingolipids" class. As noted above, these are compounds which have a backbone of sphingosine or a closely related structure to which either fatty acids or ω-esterified fatty acids are linked through an amide linkage at the amino group of the sphingosine structure and in the case of a glucosylceramide, those to which saccharide moieties are linked to the terminal hydroxyl of the sphingosine structure through a glycosidic bond.

Exemplary sterols include, but are not limited to, Brassica Campestris sterols, C10-C30 cholesterol / lanosterol esters, canola sterols, cholesterol, cholesterols, glycine soja sterols, PEG-20 phytosterol and phytosterols, and mixtures thereof.

The term "phytosterol" refers to plant sterols and plant stanols. Plant sterols are naturally occurring cholesterol-like molecules found in all plants, with the highest concentrations occurring in vegetable oils. Plant stanols are hydrogenation compounds of the respective plant sterols.

Phytosterols are natural components of common vegetable oils. Exemplary sources of phytosterols useful in this regard include, but are not limited to, shea butter, vegetable oil, tall oil, sesame oil, sunflower oil, sunflower seed oil, rice bran oil, cranberry seed oil, pumpkin seed oil and avocado wax, and mixtures thereof. In one particular embodiment, the source of phytosterols is shea butter.

The majority of the previously known compositions contain cholesterol, or an animal- based sterol, rather than a phytosterol. The use of a phytosterol in embodiments of the present invention, rather than cholesterol, is advantageous.

In this regard, phytosterols are typically incorporated in the basal membrane of the skin and can pass to the skin surface through the differentiation of skin cells. Accordingly, phytosterols provide an improved caring and protecting effect. The topical application of phytosterols also usually leads to an increased skin moisture level and to increased lipid content. This improves the desquamation behavior of the skin and reduces erythemas which may be present. R. Wachter, Parf. Kosm, Vol. 75, p. 755 (1994) and R. Wachter, Cosm. Toil, Vol. 1 10, p. 72 (1995), each of which are incorporated herein by reference in their entirety, further demonstrate these advantageous properties of phytosterols.

As used herein, cholesterol derivative is any suitable dermatologically acceptable sterol variation of cholesterol.

Exemplary hydrocarbons include, but are not limited to, dodecane, petrolatum, mineral oil, squalane, squalene and paraffin, and mixtures thereof.

In an embodiment, the hydrocarbon is squalane. Squalane helps enhance the skin's natural barrier function, protect the skin against the elements, and boost the skin's ability to retain moisture. Squalane is a component of human stratum corneum.

Squalane is available in purified form (see e.g. Fitoderm® available from BASF) and may be used in the compositions in its purified form. Alternatively, an oil which is rich in squalane may be used.

Exemplary sources of squalane useful in the present compositions include, but are not limited to, shark liver oil, olive oil, palm oil, wheat germ oil, amaranth oil, rice bran oil and sugar cane. In one embodiment, the squalane is isolated from olive oil.

Exemplary essential oils include, but are not limited to, primrose oil, rose oil, eucalyptus oil, borage oil, bergamot oil, chamomile oil, citronella oil, lavender oil, peppermint oil, pine oil, pine needle oil, spearmint oil, tea tree oil and wintergreen oil, and mixtures thereof.

Exemplary vegetable oils include, but are not limited to, olus (vegetable) oil, almond oil, aniseed oil, canola oil, castor oil, coconut oil, com oil, avocado oil, cottonseed oil, olive oil, palm kernel oil, peanut oil, sunflower oil, safflower oil and soybean oil, and mixtures thereof.

One embodiment is the use of olive oil and/or vegetable oil.

Exemplary edible oils include, but are not limited to, cinnamon oil, clove oil, lemon oil and peppermint oil, and mixtures thereof. In one embodiment, the oil and/or fat is a fatty acid, a source of fatty acids, or an ester of glycerin as described herein. Advantageously, many of the oils and/or fats used in the present compositions are the same or similar to the lipids found in human stratum comeum.

Suitably, the discontinuous oil phase is present in an amount from about 20% to about 70% by weight, based on the total weight of the composition.

Aqueous phase

The compositions of the invention comprise a continuous aqueous phase. The aqueous phase comprises water. Suitably, any additional components such as glycerin and any other water soluble excipients will be dissolved in this aqueous phase. Suitably, the continuous aqueous phase is present in an amount from about 10% to about 90% by weight, based on the total weight of the composition. In an embodiment, the continuous aqueous phase is present in an amount from about 25% to about 75% by weight, based on the total weight of the composition. In another embodiment, the continuous aqueous phase is present in an amount from about 10% to about 70% by weight, based on the total weight of the composition.

In an embodiment, the continuous aqueous phase comprises water in an amount from about 10 to about 60% by weight, in another embodiment from about 20% to about 40% by weight, and in another embodiment from about 10% to about 35% by weight, based on the total weight of the composition.

In an embodiment, the continuous aqueous phase comprises glycerin present in an amount from about 12% to about 40% by weight, based on the total weight of the composition. In another embodiment, the continuous aqueous phase comprises glycerin in an amount from about 18% to about 30% by weight, based on the total weight of the composition. In another embodiment, the continuous aqueous phase comprises glycerin in an amount from about 20% to about 40% by weight, based on the total weight of the composition. In another embodiment, the continuous aqueous phase comprises glycerin in an amount from about 20% to about 30% by weight, based on the total weight of the composition. In yet another embodiment, the continuous aqueous phase comprises glycerin in an amount from about 20% to about 25% by weight, based on the total weight of the composition. In another embodiment, the continuous aqueous phase comprises glycerin in an amount of about 20%, 21 %, 22%, 23%, 24 or 25% by weight, based on the total weight of the composition.

In one embodiment, the continuous aqueous phase may also include a sugar alcohol, such as glucose, glycerol, sorbitol, mannitol, maltitol, galactitol, erythritol, xylitol, inositol, lactitol, and mixtures thereof. In one embodiment, the sugar alcohol is glucose. The sugar alcohol may be present in an amount from about 1% to about 20% by weight, based on the total weight of the composition. In one embodiment of the disclosure, the amount of sugar alcohol is from about 10% to about 15% by weight, based on the total weight of the composition. In an embodiment, the amount of sugar alcohol is about 10, 1 1, 12, 13, 14 or 15% by weight, based on the total weight of the composition.

The continuous aqueous phase may further comprise other water miscible components, such as for example, humectants and pH adjusting agents.

Thickening agent

The compositions of the invention comprise a thickening agent or rheology modifier. In an embodiment, the thickening agent is a mixture of two or more thickening agents. The function of the thickening agent is to stabilize the discontinuous oil phase of the composition. The thickening agent may also provide hardness and structural support useful in forming a stick composition, for example. Thickening agents may be water miscible which are used to thicken the aqueous portion of the emulsion composition.

Other thickening agents are nonaqueous making them suitable for thickening the oil phase of the emulsion composition. Yet other thickening agents may act at the oil-water interface and thus lie at the interphase boundary.

Exemplary water miscible thickening agents include, but are not limited to, a cellulose derivative such as carboxymethylcellulose, hydroxy ethylcellulose, hydroxypropylcellulose, hydroxypropyl methylcellulose; agar; carrageenan; curdlan; gelatin; gellan; β-glucan; tragacanth gum; guar gum; gum arabic; locust bean gum; pectin; starch; a carbomer, such as sodium carbomer; a xanthan derivative such as dehydroxanthan gum and xanthan gum; salts thereof, or a combination or mixture thereof. Exemplary nonaqueous thickening agents include, but are not limited to, acrylate copolymers, VP/Eicosene copolymer, waxes, fatty alcohols and fatty acids such as described herein. In an embodiment, the thickening agent is an aery late copolymer, such as acrylates/C 10-30 alkyl acrylate cross polymer.

In one embodiment, the thickening agent is xanthan gum. In another embodiment, the thickening agent is dehydroxanthan gum. In yet another embodiment, the thickening agent is a carbomer or a salt thereof, such as sodium carbomer. In a further embodiment, the thickening agent is hydroxy ethylcellulose.

In one embodiment, the thickening agent is a fatty alcohol. Suitable fatty alcohols include, but are not limited to, behenyl alcohol, isostearyl alcohol, caprylyl alcohol, decyl alcohol, lauryl alcohol, myristyl alcohol, lanolin alcohol, arachidyl alcohol, oleyl alcohol, palm alcohol, isocetyl alcohol, cetyl alcohol, stearyl alcohol and cetearyl alcohol, and mixtures thereof. In one embodiment, the thickening agent comprises a mixture of fatty alcohols, a cellulose derivative, a xanthan derivative, a non-aqueous agent, and a carbomer. In one

embodiment, the thickening agent comprises behenyl alcohol, dehydroxanthan gum, VP/Eicosene copolymer, acrylates/C 10-30 alkyl acrylate cross polymer and sodium carbomer.

Suitably, the thickening agent is present in an amount from about 0.5% to about 10% by weight, based on the total weight of the composition. In an embodiment, the thickening agent is present in an amount from about 1% to about 5% by weight, based on the total weight of the composition.

Lamellar membrane structure

The compositions of the invention comprise at least one lamellar membrane structure. Generally this refers to a planar lipid bilayer sheet, or a slight curve around a droplet of oil. They may also exist as separate discrete lamellae in the bulk aqueous phase. This is in contrast to a rounded formed liposomal structure. In another embodiment, the respective lamellar membrane structures form two or more stacked lamellar membrane structures. Two lamellar membrane structures stacked together, one on top of the other, is known as a double lamellar membrane structure. Figure 1 illustrates the key physical difference between an oil in water emulsion that can form a lamellar structure (A) and a liposome (B). In an O/W emulsion the surfactant- emulsifiers orientate so that the hydrophilic heads face out into the continuous phase and the hydrophobic tails are anchored within the oil droplet. In the case of a liposome, these are typically aqueous filled cores where the hydrophilic heads of the interfacial layer of surfactant- emulsifer (here shown as a dialkyl phospholipid which can form liposomal structures) orientated toward the hydrophilic aqueous core and for the outermost layer, orientated towards the continuous phase.

Even if systems contain lamellar forming ingredients such as those further described herein, those systems can be prepared in a manner that will yield either a liposome or OAV emulsion. The physical characteristics of each system is different and is outlined below.

The properties described above are measurable using standard lab measurement methods available in the art. All of these properties will clearly provide for an accurate designation of those OAV emulsions (microscopy, rheology, visual assessment) having lamellar structures (e.g. with FTIR/XRD).

According to the invention, the at least one lamellar membrane structure comprises (i) a dialkyl amphiphilic component and (ii) an ester of a branched fatty acid and a branched fatty alcohol. That is, the lamellar membrane structure comprises a blend of (i) a dialkyl amphiphilic component and (ii) an ester of a branched fatty acid and a branched fatty alcohol. This blend is referred herein as the lamellar membrane blend.

Suitably, the lamellar membrane blend is present in an amount from about 5% to about 20% by weight, based on the total weight of the composition. In an embodiment, the lamellar membrane blend is present in an amount from about 5% to about 15% by weight, based on the total weight of the composition. In another embodiment, the lamellar membrane blend is present in an amount of about 8%, 9%, 10%, 11 % or 12% % by weight, based on the total weight of the composition. In another embodiment, the lamellar membrane blend is present in an amount of about 10% by weight, based on the total weight of the composition.

In an embodiment, the lamellar membrane blend is solubilized in the oil phase of the oil- in-water emulsion.

The term "long chain" as used herein refers to a hydrocarbon backbone chain suitably composed of 12 to 36 carbon atoms. In one embodiment, the chain is 12 to 30 carbon atoms. In one embodiment, the chain is 16 to 26 carbon atoms. In another embodiment the chain is 16 to 22 carbon atoms. In one embodiment, the chain is 22 to 30 carbon atoms. In one embodiment, the chain is 16 to 26 carbon atoms. In another embodiment the chain is 16 to 22 carbon atoms. In another embodiment, the chain is 20 to 22 carbon atoms. In another embodiment, the chain is from 20 to 30 carbon atoms, suitably 22 to 30 carbon atoms. In another embodiment the chain is from 22 to 28 carbon atoms.

The term "fatty" as used herein with reference to "fatty alcohol" or "fatty acid", etc. refers to a "long chain" hydrocarbon backbone chain suitably composed of 12 to 30 carbon atoms. In one embodiment, the chain is 16 to 26 carbon atoms. In another embodiment the chain is 16 to 22 carbon atoms. In another embodiment, the chain is 20 to 22 carbon atoms. In another embodiment, the chain is from 20 to 30 carbon atoms, suitably 22 to 30 carbon atoms. In another embodiment the chain is from 22 to 28 carbon atoms. Dialkyl amphiphilic component

The term "dialkyl amphiphilic component" as used herein refers to a component having both hydrophilic and lipophilic properties. In an embodiment, the dialkyl amphiphilic component comprises a large hydrophilic head group and a long hydrophobic tail comprising two alkyl groups. In an embodiment, the two alkyl groups are long chain alkyl groups.

The dialkyl amphiphilic component may be ionic, i.e. anionic or cationic, or non-ionic. When the dialkyl amphiphilic component is anionic, the anionic functionality can be provided by, for example, a phosphorus acid group or salt thereof or a sulphur acid group or salt thereof. Suitable phosphorus acid groups include -OP(=0)(OH)0-,

-(OA)nOP(=0)(OH)0-, and -(OA) _n OP(=0)(OH)0(AO) _m -, where A represents an alkylene group, for example ethylene, propylene, and so on, and m and n are from 1 to 60, desirably 5 to 30. Suitable sulphur acid groups include sulphosuccinate: -OC(0)CH(S0 ₃ H)CH ₂ C(0)0-, and alkoxylated sulphosuccinates:

-(OA)n OC(0)CH((S0 ₃ H)CH ₂ C(0)0-, and -(OA) _n OC(0)CH((S03H)CH ₂ C(0)0(AO)m-, where A, n and m are as defined above. When the dialkyl amphiphilic component is cationic, the cationic functionality may be provided by, for example, dialkyl dimethyl amines: -N ⁺ (CH3) ₂ -, or imidazolines.

When the dialkyl amphiphilic component is nonionic, the nonionic hydrophilic functionality may be provided by, for example, esters of sorbitol, sorbitan, sucrose and polyglycerol, and alkoxylates thereof.

In an embodiment, the dialkyl amphiphilic component is ionic. In another embodiment, the dialkyl amphiphilic component is anionic. In an embodiment, the anionic functionality is provided by a phosphorus acid group or a salt thereof. In another embodiment, the anionic functionality is provided by a phosphate group.

In one embodiment, the dialkyl amphiphilic component is a salt. In another embodiment, the salt forming moiety is an alkali metal, particularly lithium, sodium or potassium, ammonium, including amine or hydroxyl-substituted amine, e.g. alkanoamine, onium, or amine, particularly alkylamine, especially tertiary alkylamine and hydroxy-substituted amine, e.g. alkanoamine, especially tertiary alkanoamine such as triethanolamine. Salts can generally be made from free acid precursors by direct reaction with an appropriate base. Desirably, the salt forming moiety is an alkali metal. In one embodiment, the metal is sodium or potassium. In another embodiment it is potassium.

The dialkyl functionality of the amphiphilic component may be provided by any two suitable alkyl groups. In an embodiment, the alkyl groups are long chain alkyl groups. The alkyl groups may be the same or different. In an embodiment, the alkyl groups are the same as each other.

Each alkyl group may be independently selected from the group including linear and branched alkyl groups. As used herein, the term alkyl refers to any saturated hydrocarbyl group which is a monovalent radical having the general formula C _n H _2n +i. The alkyl groups may each independently contain one or more unsaturated bonds, i.e. one or more double C=C bonds. In an embodiment, each alkyl group is independently selected from the group consisting of CIO to C30 alkyl groups. In another embodiment, each alkyl group is independently selected from the group consisting of C12 to C26 alkyl groups. In yet another embodiment, each alkyl group is independently selected from the group consisting of C14 to C22 alkyl groups. In one embodiment, the alkyl groups are CI 6 alkyl groups.

In an embodiment, the dialkyl amphiphilic component may optionally be present in combination with a monoalkyl amphiphilic component. When present, the monoalkyl amphiphilic component is a monoalkyl equivalent of the dialkyl amphiphilic component, i.e. the monoalkyl amphiphilic component is the same as the dialkyl amphiphilic component with one alkyl group substituted by H or a short chain alkyl group, for example, a methyl, ethyl or propyl group.

In one embodiment, the dialkyl amphiphilic component is potassium dicetyl phosphate.

In another embodiment, the monoalkyl amphiphilic component is potassium cetyl phosphate.

In yet another embodiment, the lamellar membrane blend comprises a combination of potassium dicetyl phosphate and potassium cetyl phosphate.

In an embodiment, the dialkyl amphiphilic component has a packing parameter, R, from about 0.25 to about 1.25. In another embodiment, the dialkyl amphiphilic component has a packing parameter, R, from about 0.3 to about 1.1. In yet another embodiment, the dialkyl amphiphilic component has a packing parameter, R, from about 0.5 to about 1. Suitably, the packing parameter, R, of the dialkyl amphiphilic component corresponds to a cylindrical or lamellar amphiphilic association structure. The packing parameter is calculated according to the formula:

R=v/al,

in which v is the real volume of the dialkyl chain, a is the cross-sectional area of the amphiphilic component head group, i.e. the ionic or non-ionic group, and 1 is the approximate length of the amphiphilic component hydrocarbon chain. The packing parameter is described in more detail in S. Friberg, J. Soc. Cosmet. Chem, 1990, 41, 155- 171 , the contents of which is hereby incorporated by reference.

In an embodiment, the dialkyl amphiphilic component is present in an amount from about 1 % to about 75% by weight, based on the total weight of the lamellar membrane blend. In another embodiment, the dialkyl amphiphilic component is present in an amount from about 5% to 50% by weight, based on the total weight of the lamellar membrane blend. In yet another embodiment, the dialkyl amphiphilic component is present in an amount from about 10% to 35% by weight, based on the total weight of the lamellar membrane blend. In a further embodiment, the dialkyl amphiphilic component is present in an amount from about 15% to 25% by weight, based on the total weight of the lamellar membrane blend.

Ester of a branched fatty acid and a branched fatty alcohol

In an embodiment, the ester formed from a branched or straight chain fatty acid and a branched or straight chain fatty alcohol comprises a mixture of compounds having mono- and poly -branching in the acid and alcohol originating parts of the ester. In one embodiment, the fatty acid and fatty alcohol are alkyl branched. In an embodiment, when the composition comprises an ester of a branched or straight chain fatty acid and a branched or straight chain fatty alcohol, the composition may further comprise a fatty acid.

It is recognized that because there are two components to the ester, either one or both of them can be branched or straight chained components, e.g. the ester can be mixed. For example, the fatty acid component may be branched and the fatty alcohol may be straight chained. Alternatively, the fatty acid component may be straight chained and the fatty alcohol may be branched. In another embodiment, both the acid and the alcohol may be branched. In yet another embodiment both the acid and the alcohol may be straight chained. In one embodiment, the branched fatty acid component of the ester is a C ₁₂ to C ₃ 6 branched or straight chain fatty acid, a C 12 to C30 branched or straight chain fatty acid, a CM to C26 branched or straight chain fatty acid, a CI 6 to C22 branched or straight chain fatty acid, or a CI 8 branched or straight chain fatty acid. In one embodiment, the branched fatty acid component of the ester is a CI 8 branched fatty acid.

In an embodiment, the fatty acid component of the ester is branched, and in one embodiment is a C12 to C30 fatty acid, a C 14 to C26 fatty acid, a C 16 to C22, or a C 18 fatty acid. Fatty acids suitable for use herein can be obtained from natural sources. For example, the fatty acids may be obtained from palm oil, rape seed oil, palm kernel oil, coconut oil, babassu oil, soybean oil, castor oil, sunflower oil, olive oil, linseed oil, cottonseed oil, safflower oil, tallow, whale or fish oils, grease, lard and mixtures thereof. The fatty acids can also be synthetically prepared. Relatively pure unsaturated fatty acids such as oleic acid, linoleic acid, linolenic acid, palmitoleic acid, and elaidic acid may be isolated, or relatively crude unsaturated fatty acid mixtures employed. The fatty acid component of the ester may comprise a mixture of branched and linear fatty acids. In one embodiment, the fatty acid mixture comprises greater than about 70% of fatty acid. In one embodiment the fatty acid mixture comprises from about 73% to about 95%, or about 77% to about 90%, or about 80% to about 85% by weight of branched fatty acids, and less than about 30%, or from about 5% to about 27%, or from about 10% to about 23%, or about 15% to about 20% by weight of linear fatty acids, based on the total weight of fatty acids present.

The fatty acid component of the ester may comprise a mixture of branched and linear fatty acids. The fatty acid component of the ester is In one embodiment branched and comprises alkyl side chains (attached directly to a carbon atom of the longest linear chain) having on average less than 3, or less than 2.5, or in the range from 1.05 to 2, or from 1.1 to 1.4 carbon atoms, i.e. the side branches are predominantly methyl groups. In an embodiment, greater than 50%, or greater than 60%, or in the range from 70% to 97%, or in the range from 80% to 93% by number of the side-branched groups are methyl groups. In a further embodiment, greater than 30%, or greater than 40%, or in the range from 45% to 90%, and especially 50% to 80% by number of the branched fatty acids contain single methyl side branches. Suitable branched chain fatty acids for use in the ester of the lamellar membrane blend include iso-acids such as isostearic acid, isopalmitic acid, isomyristic acid, isoarachidic acid and isobehenic acid, neo-acids such as neodecanioc acid, and/or anti-iso acids. In an embodiment, the branched chain fatty acid is an iso-acid. Suitably, the fatty acid is isostearic acid.

In one embodiment, the fatty alcohol component of the ester is a C12 to C36 alcohol, or a C 12 to C30 alcohol, or a C 14 to C26 alcohol, or a C 16 to C22, or a C 18 fatty alcohol. In one embodiment, all of the chains are branched. In one embodiment, the branched or straight chain fatty alcohol component of the ester is made from the fatty acid component of the ester. Therefore, the same preferences apply to the branched fatty alcohol component of the ester as to the branched fatty acid component of the ester. In one embodiment, the chain length of the fatty alcohol component of the ester is the same as the chain length of the fatty acid component of the ester.

Alternatively, a mixture of branched and linear fatty alcohols may be present in the fatty alcohol component of the ester. In one embodiment, the fatty alcohol mixture comprises greater than 70%, or in the range from 73% to 95%, or in the range from 77% to 90%, or in the range from 80% to 85% by weight of branched fatty alcohols, and less than 30%, or in the range from 5% to 27%, or 10% to 23%, or 15% to 20% by weight of linear fatty alcohols, both based on the total weight of fatty alcohol present. Suitable branched fatty alcohols for use in the ester of the lamellar membrane blend include iso-alcohols such as isostearyl alcohol, isotetradecanol, isocetyl alcohol, isoarachidyl alcohol, isobehenyl alcohol and isolignoceryl alcohol; neo-alcohols such as neocapric alcohol; and/or anti-iso alcohols. In one embodiment, the branched chain fatty alcohol is an iso-alcohol. In one embodiment, the branched chain fatty alcohol is isostearyl alcohol.

In one embodiment, the ester is an ester of a C I 6-22 branched fatty acid and a CI 6-22 branched fatty alcohol. The branched fatty acid and branched fatty alcohol may comprise the same number of carbon atoms, or a different number of carbon atoms. In one embodiment, the branched fatty acid and branched fatty alcohol comprise the same number of carbon atoms.

The ester may comprise one or more variations selected from the group comprising mono- branched fatty acid and poly-branched fatty alcohol, mono-branched fatty acid and mono- branched fatty alcohol, poly-branched fatty acid and mono-branched fatty alcohol, and poly-branched fatty acid and poly-branched fatty alcohol. The ester may be selected from this group by any suitable separation method. For example, the selected ester may be selected from a mixture of esters using a clathration method. In an embodiment, the ester is an ester of a C½ to C30 mono and/or poly-branched fatty acid and a Ci6 to C30 mono and/or poly branched fatty alcohol.

In one embodiment, the ester comprises a C 18 mono- and/or poly-branched fatty acid and a C 18 mono- and/or poly-branched fatty alcohol. In one embodiment, the ester is isostearyl isostearate.

In one embodiment, the ester is present in the lamellar membrane blend in an amount from about 1 % to 75% by weight, or from about 5% to about 50% by weight. In one embodiment from about 14% to about 35% by weight, or from about 18% to about 27% by weight, based on the total weight of the lamellar membrane blend.

In one embodiment, the ester of a branched fatty acid and a branched fatty alcohol and the dialkyl amphiphilic component are present in the lamellar membrane blend at a ratio by weight of about 10: 1 to about 1 : 10, or about 5: 1 to about 1 :5, or about 2: 1 to about 1 :2. Desirably, the ester of a branched fatty acid and a branched fatty alcohol and the dialkyl amphiphilic component are present in the lamellar membrane blend at a ratio by weight of about 1.25: 1.

Fatty acid

In an embodiment, the lamellar membrane blend further comprises a fatty acid or a mixture thereof. In one embodiment the fatty acid is a C12 to C36, or a C12 to C32, or a C16 to C30, or a CI 8 to C28 fatty acid, or a CI 8 to C24 carbon chain. The fatty acid may be branched or linear. In one embodiment, the fatty acid is linear.

Fatty acids suitable for use in the lamellar membrane blend can be obtained from the same natural sources as the branched fatty acid component of the ester. A mixture of fatty acids may be present in the lamellar membrane blend. In one embodiment, when present, the fatty acid mixture comprises greater than 70%. In another embodiment, the fatty acid mixture comprises in the range from 73% to 95% w/w%, or about 77% to 90%, or about 80% to 85% by weight of linear fatty acids, and less than 30%, or in the range from 5% to 27%, or 10% to 23%, or 15% to 20% by weight of branched fatty acids, both based on the total weight of fatty acids present.

Suitable fatty acids for use in the lamellar membrane blend include lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid and cerotinic acid.

In one embodiment, the fatty acid is selected from the group consisting of stearic acid, arachidic acid, behenic acid, lignoceric acid and cerotinic acid, or mixtures thereof. In another embodiment, the fatty acid is selected from arachidic acid, behenic acid and lignoceric acid, and mixtures thereof. In another embodiment, the fatty acid is stearic acid or behenic acid, or a mixture thereof. In one embodiment, the fatty acid is stearic acid. In another embodiment, the fatty acid is behenic acid.

In one embodiment, the fatty acid or mixture thereof is present in the lamellar membrane blend in an amount from about 1% to about 75% by weight. In another embodiment the fatty acid or mixture thereof is present from about 5% to about 50% by weight. In another embodiment the fatty acid or mixture thereof is present from about 14% to about 35% by weight. In another embodiment the fatty acid or mixture thereof is present from about 18% to about 25% by weight, based on the total weight of the lamellar membrane blend. When a fatty acid, or mixture of fatty acids, is present in the lamellar membrane blend, the acid, or mixture of acids, is present relative to the ester of a branched fatty acid and a branched fatty alcohol in a weight ratio of about 10: 1 to about 1 : 10. In another embodiment in a weight ratio of from about 5: 1 to about 1 :5. In another embodiment, in a weight ratio of from about 2: 1 to about 1 :2. Desirably, the fatty acid, or mixture of fatty acids, and the ester of a branched fatty acid and a branched fatty alcohol are present in the blend at a weight ratio of about 1 : 1. When a fatty acid, or mixture of fatty acids, is present in the lamellar membrane blend, the fatty acid, or mixture of fatty acids, is present relative to the dialkyl amphiphilic component at a weight ratio from about 10: 1 to about 1 : 10. In one embodiment from about 5 : 1 to about 1 :5. In another embodiment from about 2: 1 to about 1 :2. Desirably, the acid, or mixture of acids, and the dialkyl amphiphilic component are present in the blend at a weight ratio of about 1.25 : 1.

Fatty alcohol

In another embodiment, the lamellar membrane blend further comprises a fatty alcohol, or a mixture thereof. When present, the fatty alcohol is a C12 to C36, or a C 12 to C28, or a C 14 to C26 or a C 16 to C24 fatty alcohol. In one embodiment, the chain length of the fatty alcohol is within 4 carbon atoms of the alkyl chain length of the dialkyl amphiphilic component. In one embodiment, the chain length of the fatty alcohol is within 2 carbon atoms of. In another embodiment, the chain length of the fatty alcohol is the same as the alkyl chain length of the dialkyl amphiphilic component. The fatty alcohol may be branched or linear. In one embodiment, the fatty alcohol is linear.

A mixture of fatty alcohols may be present in the lamellar membrane blend. In this case, the main component of the mixture of fatty alcohols is within 4 carbon atoms of, or within 2 carbon atoms of or is the same as the alkyl chain length of the dialkyl amphiphilic component.

In one embodiment, the fatty alcohol mixture comprises greater than 70%, or is from about 73% to about 95%, or is about 77% to about 90%, or about 80% to about 85% by weight of linear fatty alcohols, and less than 30% by weight. In another embodiment, the fatty alcohol mixture in the range from about 5% to about 27%, or about 10% to about 23%, or about 15% to about 20% by weight of branched fatty alcohols, both based on the total weight of fatty alcohol present. Suitable fatty alcohols for use in the lamellar membrane blend include but are not limited to, lauryl alcohol, tetradecanol, cetyl alcohol, stearyl alcohol, arachidyl alcohol, behenyl alcohol and lignoceryl alcohol, and mixtures thereof. In one embodiment, the fatty alcohol is selected from the group consisting of lauryl alcohol, tetradecanol, cetyl alcohol, stearyl alcohol, arachidyl alcohol and behenyl alcohol. In another embodiment, the fatty alcohol is selected from tetradecanol, cetyl alcohol, stearyl alcohol and behenyl alcohol. In yet another embodiment, the fatty alcohol is cetyl alcohol, or is behenyl alcohol, or a mixture of cetyl alcohol and behenyl alcohol. In one embodiment, the fatty alcohol or mixture thereof is present in the lamellar membrane blend in an amount from about 10% to about 85% by weight. In one embodiment from about 15% to about 70% by weight. In one embodiment from about 25% to about 55% by weight, or from about 30% to about 40% by weight, based on the total weight of the lamellar membrane blend.

When a fatty alcohol, or mixture of fatty alcohols, is present in the lamellar membrane blend, the fatty alcohol, or mixture of fatty alcohols, is present relative to the ester of a branched fatty acid and a branched fatty alcohol at a weight ratio from about 12: 1 to about 1 : 10, or from about 6: 1 to about 1 :5, or from about 4: 1 to about 1 : 1. In one embodiment, the fatty alcohol, or mixture of fatty alcohols, and the ester of a branched fatty acid and a branched fatty alcohol are present in the lamellar membrane blend at a weight ratio of about 1.6: 1.

When a fatty alcohol, or mixture of fatty alcohols, is present in the lamellar membrane blend, the fatty alcohol, or mixture of fatty alcohols, is present relative to the dialkyl amphiphilic component at a weight ratio of about 10: 1 to about 1 : 10. In one embodiment, the ratio is from about 5 : 1 to about 1 :5. In another embodiment, the ratio is from about 2: 1 to about 1 :2. In yet another embodiment, the fatty alcohol, or mixture of fatty alcohols, and the dialkyl amphiphilic component are present in the lamellar membrane blend at a weight ratio of about 2: 1.

When a fatty alcohol, or mixture of fatty alcohols, and a fatty acid, or mixture of fatty acids, are present in the blend, the fatty alcohol, or mixture of fatty alcohols, is present relative to the fatty acid, or mixture of fatty acids at a weight ratio from about 10: 1 to about 1 : 12. In one embodiment, the ratio is from about 5 : 1 to about 1 :6. In another embodiment, the ratio is from about 2: 1 to about 1 :4. In yet another embodiment, the fatty alcohol, or mixture of fatty alcohols, and the fatty acid, or mixture of fatty acids are present in the lamellar membrane blend at weight ratio of about 1 : 1.6. The fatty alcohol, or mixture of fatty alcohols, and the fatty acid, or mixture of fatty acids may react to form an ester when both present in the lamellar membrane blend. In one embodiment, the ester, when formed, is a cetyl behenate or cetyl stearate ester. The lamellar membrane blend may be made in accordance with the disclosure of WO 2012/104604, Pennick et al, and US 2013/0324499, Pennick et al, whose disclosures are incorporated herein by reference. The lamellar membrane blend is commercially available as a pastillated and/or flaked product from Croda International PLC. In one embodiment of the disclosure, there is provided a lamellar membrane blend for use in a lip protectant composition, the lamellar membrane blend comprising (a) a dialkyl amphiphilic component and b) an ester of a branched fatty acid and a branched fatty alcohol. In another embodiment, there is provided a lamellar membrane blend for use in a lip protectant composition, the lamellar membrane blend comprising (a) a dialkyl amphiphilic component, b) an ester of a branched fatty acid and a branched fatty alcohol, (c) a fatty acid and (d) a fatty alcohol. In yet another embodiment, the lamellar membrane blend comprises isostearyl isostearate, potassium dicetyl phosphate, behenic acid, cetyl alcohol and cetyl behenate.

In yet another embodiment, the lamellar membrane blend comprises isostearyl isostearate, potassium dicetyl phosphate, behenic acid, cetyl alcohol, behenyl alcohol and cetyl behenate.

In a further embodiment, the lamellar membrane blend comprises isostearyl isostearate, potassium dicetyl phosphate, potassium cetyl phosphate, behenic acid, cetyl alcohol and cetyl behenate. This may be available commercially from Croda International PLC as DuraQuench IQ.

In one embodiment, the lamellar membrane blend comprises isostearyl isostearate, potassium dicetyl phosphate, stearic acid, cetyl alcohol and cetyl stearate. In one embodiment, the lamellar membrane blend comprises isostearyl isostearate, potassium dicetyl phosphate, stearic acid, cetyl alcohol, behenyl alcohol and cetyl stearate. In another embodiment, the lamellar membrane blend comprises isostearyl isostearate, potassium dicetyl phosphate, potassium cetyl phosphate, stearic acid, cetyl alcohol and cetyl stearate. This may be available commercially from Croda International PLC as DuraQuench IQ-SA.

Dermatologically acceptable excipients

The compositions of the invention may further comprise at least one dermatologically acceptable excipient. In an embodiment, the dermatologically acceptable excipient is selected from the group consisting of an antioxidant, a chelating agent, a preservative, a colorant, a sensate, a moisturizer, a humectant, a lip conditioning agent and a pH adjusting agent, and mixtures thereof. In an embodiment, the compositions of the invention are free or substantially free of a conventional emulsifier.

Antioxidant

The compositions of the invention may further comprise an antioxidant. In an

embodiment, the antioxidant is a mixture of two or more antioxidants.

Antioxidants may protect the composition from oxidation (e.g. becoming rancid) and/or provide lip conditioning benefits upon application to the lips. Tocopherol, tocopheryl acetate, some botanical butters, niacinamide, pterostilbene (trans-3,5-dimethoxy-4- hydroxystilbene) magnolol, and green tea extracts, alone or in combination thereof are exemplary natural product antioxidants suitable for use in the compositions. Other suitable antioxidants include ascorbic acid and esters thereof such as ascorbyl palmitate, butylated hydroxy toluene (BHT), butylated hydroxyanisole (BHA), propyl gallate, vitamin E TPGS, ethyl ferulate, ferulic acid, resveratrol, 2,2-dimethyl chroman (Lipochroman®) , singapine, tetrahydrocurcumin or other curcumin derivaties, hydroxytyrosol, Bis-Ethylhexyl Hydroxy dimethoxy Benzylmalonate (Ronacare AP ®), dimethylmethoxy chromanyl palmitate (Chromabright®) or a combination or mixture thereof. It is recognized that a combination or mixture of all of these antioxidants is also suitable for use herein. In one embodiment, the antioxidant is tocopherol, or a mixture of tocopherol and ascorbyl palmitate. In another embodiment, the antioxidant is niacinamide.

Suitably, the antioxidant is present in an amount from about 0.001 % to about 1 % by weight, based on the total weight of the composition. Chelating agents

The compositions of the invention may further comprise a chelating agent. In an embodiment, the chelating agent is a mixture of two or more chelating agents.

Exemplary chelating agents include, but are not limited to, citric acid, glucuronic acid, sodium hexametaphosphate, zinc hexametaphosphate, ethylenediamine tetraacetic acid (EDTA), ethylenediamine disuccinic acid (EDDS), phosphorates, salts thereof, or a combination or mixture thereof.

In one embodiment, the chelating agent is EDTA or a salt thereof, such as potassium, sodium or calcium salts of EDTA. In another embodiment, the chelating agent is ethylenediamine succinic acid or a salt thereof, such as potassium, sodium or calcium salts. In one embodiment, the chelating agent is trisodium ethylenediamine disuccinate.

Suitably, the chelating agent is present in an amount from about 0.1 % to about 1% by weight, based on the total weight of the composition.

Preservative

The compositions of the invention may further comprise a preservative. In an

embodiment, the preservative is a mixture of two or more preservatives.

Exemplary preservatives include, but are not limited to, benzyl alcohol, diazolidinyl urea or other substituted ureas and hydantoin derivatives, methyl paraben, ethyl paraben, propyl paraben, butyl paraben, phenoxyethanol, sorbic acid, benzoic acid, salts thereof, or a combination or mixture thereof.

Suitably, the preservative is present in an amount from about 0.01% to about 2% by weight. In an alternative embodiment, the compositions of the invention are free of conventional preservatives.

In an embodiment, the preservative is a combination of non-conventional preservatives, such as capryloyl glycine, and other glycols. Other suitable glycols include, but are not limited to, caprylyl glycol and/or pentylene glycol. Suitably, these preservatives are present in an amount from about 0.5% to about 5% by weight, based on the total weight of the composition. In one embodiment, the capryloyl glycine is present in an amount from about 0.5% to about 2% by weight and the additional glycols can be added in amounts up to 5% by weight, based on the total weight of the composition. Suitably, the preservative is a combination of at least capryloyl glycine and caprylyl glycol in an amount from about 0.5% to about 2% by weight, based on the total weight of the composition.

Colorant

The compositions of the invention may further comprise a colorant that imparts color to the composition and/or lips. For a lip balm, the colorant should not be of an amount, particle size, and/or matrix that permits transfer of colorant to the lips during application. For a lipstick, a colorant that transfers and imparts color to the lips should be used. Colorants include, for example, natural colorants such as plant extracts, natural minerals, carmine, synthesized and/or processed colorant materials such as iron oxides, synthetic dyes, organic compounds, lake colorants, and FDA certified colorants for use on the lips. The above list is not an exhaustive list of colorants and those of skill in the art may consider the use of other colorants. Formulations of colorants are commercially available. An example of a commercially available colorant contains caprylic/capric triglycerides (59.5%), titanium dioxide (39.6%), castor oil phosphate (0.5%) and triethoxycaprylylsilane (0.4%). The use of a colorant containing titanium dioxide can affect the stability of some sunscreens such as Avobenzone. It has been observed that colorants containing coated titanium dioxide can enhance the stability of Avobenzone. Optionally, in some embodiments, it may be desirable to include a color enhancer such as, for example, a pearlescent material.

Sensate

The compositions of the invention may further comprise a sensate. A sensate is a composition that initiates a sensory perception such as heating or cooling, for example, when contacted with the skin and/or lips. Exemplary sensates include, but are not limited to, mint extracts, cinnamon extract and capsaicin. Preferred sensates are derived from natural sources. However, synthetic sensates are within the scope of this invention.

Sensates typically have high potency and accordingly may yield significant impact at low levels. Suitably, the sensate is present in an amount from about 0.05% to about 5% by weight, based on the total weight of the composition.

Moisturizer

The compositions of the invention may further comprise a moisturizer. Exemplary moisturizers useful in the present compositions include, but are not limited to, pentylene glycol, butylene glycol, polyethylene glycol, sodium pyrrolidone carboxylate, a-hydroxy acids, β-hydroxy acids, polyhydric alcohols, ethoxylated and propoxylated polyols, polyols, polysaccharides, panthenol, hexylene glycol, propylene glycol, dipropylene glycol and sorbitol and mixtures thereof. Suitably, the moisturizer is present in an amount from about 0.5% to about 10% by weight, based on the total weight of the composition.

Humectant

The compositions of the invention may comprise an additional humectant i.e. in addition to glycerol. Exemplary additional humectants useful in the present compositions include, but are not limited to, betaine, sarcosine, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, caprylyl glycol, sorbitol, glucose, and mixtures thereof. In one embodiment, the additional humectant is a mixture of pentylene glycol, caprylyl glycol and glucose.

Suitably, the additional humectant is present in an amount from about 1% to about 15% by weight, based on the total weight of the composition. Lip conditioning agent

The compositions of the invention may comprise a lip conditioning agent. Exemplary lip conditioning agents include, but are not limited to, capryloyl glycine, ceramide-3 and phytosphingosine, and mixtures thereof. Suitably, the lip conditioning agent is present in an amount from about 0.001% to about 2% by weight, based on the total weight of the composition. pH adjusting agent

The compositions of the invention may further comprise a pH adjusting agent. In one embodiment, the pH adjusting agent is a base. Suitable bases include amines,

bicarbonates, carbonates, and hydroxides such as alkali or alkaline earth metal hydroxides, as well as transition metal hydroxides. In an embodiment, the base is sodium hydroxide or potassium hydroxide. In another embodiment, the pH adjusting agent is an acid, an acid salt, or mixtures thereof. Suitably, the acid is selected from the group consisting of lactic acid, acetic acid, maleic acid, succinic acid, citric acid, benzoic acid, boric acid, sorbic acid, tartaric acid, edetic acid, phosphoric acid, nitric acid, ascorbic acid, dehydroacetic acid, malic acid, propionic acid, sulphuric acid and hydrochloric acid, or a combination or mixture thereof. In yet another embodiment, the pH adjusting agent is a buffer. Suitably, the buffer is selected from the group consisting of citrate/ citric acid, acetate/ acetic acid, phosphate/ phosphoric acid, propionate/ propionic acid, lactate/ lactic acid, carbonate/ carbonic acid, ammonium/ ammonia and edetate/ edetic acid, or a combination or mixture thereof.

Pharmaceutically active agent

The compositions of the invention may further comprise a pharmaceutically acceptable active agent. Exemplary pharmaceutically active agents include, but are not limited to, an anti-inflammatory agent, an antibacterial agent, an antiviral agent, a nutritional agent, a sunscreen, a sun block, and mixtures thereof. Suitably, the pharmaceutically active agent is present in an amount from about 0.001 % to about 30% by weight, depending on the nature of the active agent, the condition being treated, and the composition.

In an embodiment, the present lip protectant compositions enhance the effectiveness of the pharmaceutically active agent. This enhanced effectiveness may result from an improved solubility profile of the pharmaceutically active agent.

In one embodiment, the pharmaceutically active agent is an anti-inflammatory agent. Exemplary anti-inflammatory agents are niacinamide and N-acylalkanolamines including, but not limited to, lactamide monoethanolamide (MEA), oleamide MEA, acetamide MEA (AMEA), palmitidyl MEA (PMEA), N-acetylphosphatidylethanolamine, N-acetyl- ethanolamine, N-oleoylethanolamine, N-linolenoylethanolamine, N-acylethanolamine, and N-acyl-2 -hydroxy-propylamine. In one embodiment, the N-acylalkanolamine is present in an amount from about 0.01% to about 2% by weight, based on the total weight of the composition.

Suitably, the N-acylalkanolamine is present in an amount from about 0.01% to about 2% by weight, based on the total weight of the composition. In one embodiment, the N-acylalkanolamine is palmitidyl MEA (PMEA).

In another embodiment, the anti-inflammatory agent is niacinamide.

Suitably, the niacinamide is present in an amount from about 0.01 % to about 5% by weight, based on the total weight of the composition. In another embodiment, the pharmaceutically active agent is a sunscreen. Suitably, the sunscreen is at least one UVA sunscreen and/or at least one UVB sunscreen. Suitably, the sunscreen is a combination of at least one UVA sunscreen and at least one UVB sunscreen. Human lips are prone to sun damage when exposed to UVA and/or UVB radiation.

Efficacious protection from UVA and UVB radiation requires the use of significant amounts of sunscreen, and often a mixture of organic sunscreens, to achieve efficacious protection from both UVA and UVB radiation. UVB radiation, which is radiation in the wavelength range of 290 nm-320 nm, has traditionally been characterized as the radiation that causes sunburn. In addition, UVB radiation can decrease enzymatic and non- enzymatic antioxidants in the skin and impair the natural protective mechanisms in the skin, thereby contributing to DNA damage and potentially skin cancer. The dangers of UVA radiation, which is radiation in the wavelength range of 320 nm to 400 nm, have only recently been recognized. Chronic exposure to UVA radiation can cause damage to gene P53 DNA, possibly leading to cancer. Additionally, the longer UVA wavelengths allow for relatively deep penetration into the skin tissues causing damage to the elastic fibers and collagen which give skin its shape, thus causing wrinkling and eventually premature skin aging. Thus, protecting the lips from UVA and UVB radiation is important for skin health and overall health more generally.

Unfortunately, sunscreens, particularly organic sunscreens, have an unpleasant taste. Some sunscreens including Avobenzone, useful for UVA protection, have a very unpleasant taste. This unpleasant taste is not an issue for lotions that are applied to the body to protect body surfaces from sun damage, but become a significant problem when sunscreens are incorporated into lip protectant compositions as described herein. Unfortunately, there are no other available sunscreens which afford UVA protection as effectively as Avobenzone.

Conventionally, sweeteners and/or flavorants have been used to cover or mask unpleasant tastes. In this approach, the sweetener and/or flavorant competes with the undesirable taste. While this may be successful in some applications, it is not satisfactory for masking the taste of the very strong and/or bitter flavors of organic sunscreens. Additionally, the flavor and/or sweetener may lack the persistence of taste over the entire time frame that the sunscreen remains on the lips, resulting in the evolution of a distasteful sensation after a period of time.

Coatings and forms of encapsulation are other approaches for taste-masking. However, coatings and/or encapsulation may impact the effectiveness of the sunscreen. Further, coating or encapsulation of an unpleasant tasting material in a lip protectant is typically an even more difficult problem than taste-masking of an ingested material, as unlike ingested materials, the product is intended to stay on the lips for a period of several hours.

Human skin is repeatedly exposed to ultraviolet radiation (UVR) that influences the function and survival of many cell types and is regarded as the main causative factor of skin cancer. It has been traditionally believed that skin pigmentation is the most important photoprotective factor, since melanin, besides functioning as a broadband UV absorbent, has antioxidant and radical scavenging properties. There are two types of melanin found in mammals that give hair and skin its distinctive coloring, the brownish black eumelanin and the reddish yellow pheomelanin. There are recent suggestions that pheomelanin, rather than protecting the skin against UV radiation, may actually contribute to UV -induced skin damage (Thody et al, J. Invest Dermat 97:340-344 (1991)). Pheomelanin is also more concentrated on the lips in all individuals than eumelanin. The shielding effect of melanin, especially eumelanin, is achieved by its ability to serve as a physical barrier that scatters UV radiation (UVR), and as an absorbent filter that reduces the penetration of UVR through the epidermis. The efficacy of melanin as a sunscreen was assumed to be about 1.5-2.0 sun protective factors (SPF); possibly as high as 4 SPF, implying that melanin absorbs 50% to 75% of UVR. In contrast to eumelanin, pheomelanin is especially prone to photodegradation and is thought to contribute to the damaging effects of UVR because it can generate hydrogen peroxide and superoxide anions and might cause mutations in melanocytes or other cells. See Brenner et al, Photochem Photobiol, 84(3): p 539-549 (2008). A topical composition which not only moisturizes but protects the lips from UVA and UVB radiation and reduces pheomelanin damage will provide additional benefits to the patient. In particular, the present invention provides for a balanced UVA/SPF ratio of about 1 : 1 of sunscreen filters which is believed important to lip protection. Another embodiment of the present invention is a method of protecting pheomelanin in the lips of a mammal from photodegradation, the method comprising applying to the lips of the mammal in need thereof an effective amount of a topical oil-in-water emulsion

composition comprising:

(a) a discontinuous oil phase;

(b) a continuous aqueous phase comprising water and glycerin, wherein the glycerin is present in an amount greater than about 12% by weight, based on the total weight of the composition;

(c) a thickening agent; (d) at least one lamellar membrane structure comprising (i) a dialkyl amphiphilic component and (ii) an ester of a branched fatty acid and a branched fatty alcohol; and

(e) at least one UVA sunscreen and at least one UVB sunscreen; and

wherein the composition is a lip protectant composition.

Another embodiment of the disclosure is a method of protecting the lips of a mammal against reactivation of herpes simplex virus, the method comprising applying to the lips of the mammal in need thereof an effective amount of a topical oil-in-water emulsion composition comprising:

(a) a discontinuous oil phase;

(b) a continuous aqueous phase comprising water and glycerin, wherein the glycerin is present in an amount greater than about 12% by weight, based on the total weight of the composition;

(c) a thickening agent; and

(d) at least one lamellar membrane structure comprising (i) a dialkyl amphiphilic component and (ii) an ester of a branched fatty acid and a branched fatty alcohol; and

(e) at least one UVA sunscreen and at least one UVB sunscreen; and wherein the UVA/SPF protection is about 1 : 1 ; and

wherein the composition is a lip protectant composition.

Yet another embodiment of the disclosure is a method of protecting the lips of a mammal, against a reoccurrence of cold sores, the method comprising applying to the lips of the mammal in need thereof an effective amount of a topical oil-in-water emulsion composition comprising:

(a) a discontinuous oil phase;

(b) a continuous aqueous phase comprising water and glycerin, wherein the glycerin is present in an amount greater than about 12% by weight, based on the total weight of the composition;

(c) a thickening agent; and

(d) at least one lamellar membrane structure comprising (i) a dialkyl amphiphilic component and (ii) an ester of a branched fatty acid and a branched fatty alcohol; and

(e) at least one UVA sunscreen and at least one UVB sunscreen; and wherein the UVA/SPF protection is about 1 : 1 ; and

wherein the composition is a lip protectant composition. UVA filters include, but are not limited to, Avobenzone (Parsol 1789), Bisdisulizole disodium (Neo Heliopan AP), Diethylamino hydroxybenzoyl hexyl benzoate (Uvinul A Plus), Ecamsule (Mexoryl SX), Menthyl anthranilate (Meradimate), oxybenzone, sulisobenzene and dioxybenzone, and mixtures thereof.

UVB filters include, but are not limited to, Amiloxate, 4-Aminobenzoic acid (PABA), Cinoxate, Ethylhexyl triazone (Uvinul T 150), Homosalate, 4-Methylbenzylidene camphor (Parsol 5000), Octyl methoxycinnamate (Octinoxate), Octyl salicylate (Octisalate), Padimate O (Escalol 507), Phenylbenzimidazole sulfonic acid (Ensulizole), Polysilicone- 15 (Parsol SLX) and Trolamine salicylate, and mixtures thereof.

UVA + UVB filters include, but are not limited to, Bemotrizinol (Tinosorb S),

Benzophenones 1 -12, Dioxybenzone, Drometrizole trisiloxane (Mexoryl XL), Iscotrizinol (Uvasorb HEB), Octocrylene, Oxybenzone (Eusolex 4360), Sulisobenzone and

Bisoctrizole (Tinosorb M), and mixtures thereof.

Other exemplary sunscreens useful in the present invention (with maximum suitable amounts of each sunscreen in % wt/wt) include, but are not limited to, amino benzoic acid (about 15%), avobenzone (about 3%), the Cinnamates, such as but not limited to cinoxate (about 3%), and octyl methoxycinnamate (Octinoxate) (about 10%), the Salicylates, such as but not limited to homosalate (about 15%), meradimate (about 5%), octocrylene (about 10%), ethylhexyl salicylate (also known as octyl salicylate or octisalate) (about 5%), oxybenzone (about 6%), dioxybenzone (about 3%), Octyldimethyl PABA (Padimate O) (about 8%), p-amyldimethyl PABA (Padimate A) (about 3%), phenylbenzimidazole sulfonic acid (ensulizole )(about 4%), sulisobenzene (about 10%), trolamine salicylate (about 12%), benzophenone (about 10%), benzylidine compounds, such as 4- methylbenzylidine camphor (Parsol 5000) (about 6%), butyl methoxydibenzoylmethane (about 5%), bis-ethylhexyloxyphenol methoxyphenyl triazine (Bemotrizinol or Tinosorb S) (about 10%), camphor benzalkonium methosulfate (about 6%), diethyl amino hydroxy benzoyl hexyl benzoate (Uvinul A plus) (about 10%), di ethylhexyl butamido triazine (Uvasorb HEB) (about 10%), disodium phenyl dibenzy Imidazole tetrasulfonate

(Bisdisulizole disodium or NeoHeliopan AP) (about 10%), drometrizole trisiloxane (silatriazole or Mexoryl XL) (about 15%), ethylhexyl dimethyl para-amino benzoic acid (about 8%), ethylhexyl methoxycinnamate (about 10%), ethylhexyl Triazone (Uvinul T 150) (about 5%), isoamyl p-methoxycinnamate (about 10%), 4-methylbenzylidene camphor (about 10%), methylene bis-benzotriazolyl tetramethylbutylphenol (Bisoctrizole or Tinosorb M) (about 10%), PEG-25 paramainobenzoic acid (about 5%),

phenylbenziamido methylbenzylidene camphor (about 6%), diisopropyl methyl cinnamate (about 10%), dimethoxyphenyl-[l-(3,4)-4,4-dimethyl] l,3 pentanedione (about 7%), ethylhexyl dimethyloxy benzylidene dioxoimidazoline propionate (about 3%), ferulic acid (about 10%), glyceryl ethylhexanoate dimethoxycinnamate (about 10%), glycerol para- aminobenzoic acid (about 10%), phenylbenzimidazole sulfonic acid (about 3%) and Parsol SLX (benzylidene malonate polysiloxane), and mixtures thereof. The amounts listed in the preceding list are for each sunscreen individually. In some embodiments in which a combination or mixture of sunscreens is used, the total combined amount of a sunscreen may be less or equal to the sum of the maximum suitable amounts for each individual sunscreen.

As used herein, the term "Cinnamates", include but are not limited to octinoxate, cinoxate, and isoamyl p-methoxy cinnamate, and glyceryl ethylhexanoate dimethoxycinnamate.

As used herein, the term "Salicylates" include but are not limited to octisalate, homosalate, and trolamine salicylate.

As used herein, the term "Benzophenones" includes oxybenzone, sulisobenzone, and dioxybenzone. As used herein, the term "PABA and derivatives" includes PABA (p-aminobenzoic acid), Octyldimethyl PABA (Padimate O), p-amyldimethyl PABA (Padimate A), Ethyl

4[te(hydroxypropyl)] aminobenzoate, and glyceryl PABA.

Avobenzone, and benzophenones, as well as some other sunscreens, are photo unstable. Therefore these sunscreens are frequently combined with other sunscreens or stabilizers to increase the photostability of the final product. Some suitable photo stabilizers also referred to herein as boosters, include, but are not limited to Octocrylene, Diethylhexyl 2,6- naphthalate, and Diethylhexyl syringylidene malonate. In one embodiment, the photostabilizer is Diethylhexyl syringylidene malonate.

Although a single sunscreen may be used in a lip protectant composition, typically a combination of sunscreens will be used as each sunscreen has a characteristic wavelength range in which it absorbs UV radiation (UVR) and typically that range is less than the entire range for which protection is desired. Thus, use of a combination of sunscreens provides protection over a wider range of wavelengths. Additionally, efficacy of protection is also related to the amount of sunscreen. As regulatory agencies limit the amount of each sunscreen that can be used, the use of multiple sunscreens improves the SPF while maintaining regulatory compliance. Organic sunscreens and their efficacious wavelength range (along with suitable amounts) are as follows: amino benzoic acid (260 nm-313 nm, about 5% to about 15%); padimate O (290 nm-315 nm, about 1.4% to about 8%); dioxybenzone (260 nm-380 nm, about 1% to about 3%); oxybenzone (270 nm-350 nm, about 2% to about 6%); sulisobenzone (260 nm- 375 nm, about 5% to about 10%); cinoxate (270 nm-328 nm, about 1% to about 3%); octocrylene (250 nm-360 nm, about 7% to about 10%); Avobenzone (320 nm-400 nm, about 1% to about 3%); octyl salicylate (280 nm-320 nm, about 3% to about 5%);

homosalate (295 nm-315 nm, about 4% to about 15%); trolamine salicylate (260 nm-320 nm, about 5% to about 12%); octinoxate (290 nm-320 nm, about 2% to about 7.5%).

In one embodiment, at least two sunscreens are used where the first sunscreen has an efficacious wavelength range that includes about 280 nm to about 315 nm and the second sunscreen has an efficacious wavelength range that includes about 315 nm to about 400 nm.

In one embodiment, the at least one UVA sunscreen is Avobenzone. In an embodiment, the at least one UVA sunscreen is avobenzone and the composition further comprises a similiter stabilizer, which is diethylhexyl syringylidene malonate. In another embodiment, the at least one UVB sunscreen is ethylhexyl salicylate (Octisalate). In yet another embodiment, the at least one UVB sunscreen is ethylhexyl salicylate (Octisalate) and the composition further comprises a sunfilter stabilizer, which is diethylhexyl syringylidene malonate. In one embodiment, the sunscreen is a combination of avobenzone and ethylhexyl salicylate (Octisalate). In another embodiment, the sunscreen is a combination of avobenzone and ethylhexyl salicylate (Octisalate), and the composition further comprises a sunfilter stabilizer, which is diethylhexyl syringylidene malonate. In one embodiment, the UVA/SPF protection ratio is from about 1 : 1 to about 1 :3. In another embodiment, the UVA/SPF protection ratio is about 1 : 1. To determine this number, in vivo testing is performed for the SPF value and in vitro testing is performed for the UVA value. The UVA number is divided by the SPF number to obtain the protection value, for instance, a UVA value of 10 and a SPF of 10 would yield a 1/1 value.

In one embodiment, the avobenzone is present in an amount from about 2% to about 3% by weight, based on the total weight of the composition. In another embodiment, octisalate is present in an amount from about 4% to about 5% by weight, based on the total weight of the composition. In yet another embodiment, avobenzone is present in an amount from about 2% to about 3% by weight and octisalate is present in an amount from about 4% to about 5% by weight, based on the total weight of the composition. In another embodiment, avobenzone is present in an amount of about 2.75% and octisalate is present in an amount of about 4.5%, based on the total weight of the composition.

The use of avobenzone is desirable for UVA protection as it is efficacious in the range of about 320 nm to 400 nm, a range in which most sunscreens provide limited to no protection. However, avobenzone has particularly offensive organoleptic properties. The present invention provides not only for the use of efficacious amounts of avobenzone in a lip protectant but in a composition which covers the offensive taste.

In some embodiments of the invention, it may be desirable to also include inorganic sunscreens such as titanium dioxide and/or zinc oxide, for example. Such compounds may be used in amounts from about 2% to about 25% by weight, with higher amounts providing higher levels of protection. Unfortunately, although higher amounts of inorganic oxides provide better protection, they typically also impart a thick layer of white material on the skin's surface which is very undesirable on the lips. Thus for lip protectant compositions, inorganic sunscreens are in one embodiment used in combination with organic sunscreens to obtain efficacious protection.

Accordingly, the compositions of the invention have a comparatively high water content (relative to the prior art) and therefore enhance the moisturization of the lips. They are also generally free of conventional emulsifiers and thus are capable of restoring or repairing the skin lipid barrier of the lips. Furthermore, in some embodiments, the compositions protect the lips from UV damage. More specifically, the compositions are formulated to protect the lips from UVA radiation and thus assist in preventing photodegradation of

pheomelanin in the lips. The U. S. Skin Protectant monograph requires a high level of glycerin, e.g. 20% to 45% to be compliant with the monograph and be considered a lip protectant. This is very difficult to achieve in a formulation which is not tacky and still consumer friendly to use. The monograph can be found at

http://www.accessdata.fda. gov/scripts/cdrh/ cfdocs/ cfCFR/

CFRSearch.cfm?CFRPart=347. In one embodiment of the disclosure wherein the compositions comprise from about 20% to about 40% glycerin, they are in accordance with the monograph requirements.

Accordingly, the present lip protectant compositions are believed to be highly

advantageous, not only as a lip protectant but as a protectant from UV damage. The present compositions are also capable of providing significant and perhaps extended moisturization. In one embodiment, the invention provides a topical oil-in-water emulsion composition comprising:

(a) a discontinuous oil phase;

(b) a continuous aqueous phase comprising water and glycerin, wherein the glycerin is present in an amount from about 12% to about 40% by weight, based on the total weight of the composition;

(c) a thickening agent; and

(d) at least one lamellar membrane structure comprising (i) a dialkyl amphiphilic component and (ii) an ester of a branched fatty acid and a branched fatty alcohol. In another embodiment, the invention provides a topical oil-in-water emulsion composition comprising:

(a) a discontinuous oil phase;

(b) a continuous aqueous phase comprising water and glycerin, wherein the glycerin is present in an amount from about 12% to about 40% by weight, based on the total weight of the composition;

(c) a thickening agent;

(d) at least one lamellar membrane structure comprising (i) a dialkyl amphiphilic component and (ii) an ester of a branched fatty acid and a branched fatty alcohol; and

(e) optionally at least one dermatologically acceptable excipient; and

wherein the composition is a lip protectant composition.

In yet another embodiment, the invention provides a topical oil-in-water emulsion composition comprising:

(a) a discontinuous oil phase;

(b) a continuous aqueous phase comprising water and glycerin, wherein the glycerin is present in an amount from about 12% to about 40% by weight, based on the total weight of the composition;

(c) a thickening agent;

(d) at least one lamellar membrane structure comprising (i) a dialkyl amphiphilic component, (ii) an ester of a branched fatty acid and a branched fatty alcohol, (iii) a fatty acid and (iv) a fatty alcohol; and

(e) optionally at least one dermatologically acceptable excipient; and wherein the composition is a lip protectant composition.

In yet a further embodiment, the invention provides a topical oil-in-water emulsion composition comprising:

(a) a discontinuous oil phase;

(b) a continuous aqueous phase comprising water and glycerin, wherein the glycerin is present in an amount from about 12% to about 40% by weight, based on the total weight of the composition;

(c) a thickening agent;

(d) at least one lamellar membrane structure comprising (i) a dialkyl amphiphilic component, (ii) an ester of a branched fatty acid and a branched fatty alcohol, (iii) a fatty acid and (iv) a fatty alcohol; and

(e) a combination of at least one UVA sunscreen and at least one UVB sunscreen, and wherein the UVA sunscreen has a UVA/SPF protection ratio of about 1 : 1 ; and wherein the composition is a lip protectant composition.

In another embodiment, the invention provides a topical oil-in-water emulsion composition comprising:

(a) a discontinuous oil phase;

(b) a continuous aqueous phase;

(c) a thickening agent;

(d) at least one lamellar membrane structure comprising (i) a dialkyl amphiphilic component and (ii) an ester of a branched fatty acid and a branched fatty alcohol; and

(e) optionally at least one dermatologically acceptable excipient.

In all of the above combinations, the composition may optionally comprise at least one dermatologically acceptable excipient selected from an antioxidant, a chelating agent, a preservative, a colorant, a sensate, a moisturizer, a humectant, a pH adjusting agent, a pharmaceutically acceptable agent, and combinations and mixtures thereof.

Methods of treatment

The invention provides a method for moisturizing, and protecting, repairing, or restoring the skin lipid barrier of the lips of a mammal, the method comprising applying to the lips of the mammal in need thereof a therapeutically effective amount of a topical oil-in-water emulsion composition comprising:

(a) a discontinuous oil phase; (b) a continuous aqueous phase comprising water and glycerin, wherein the glycerin is present in an amount greater than about 12% by weight, based on the total weight of the composition;

(c) a thickening agent; and

(d) at least one lamellar membrane structure comprising (i) a dialkyl amphiphilic component and (ii) an ester of a branched fatty acid and a branched fatty alcohol; and

(e) optionally at least one dermatologically acceptable excipient; and

wherein the composition is a lip protectant composition.

The invention also provides for the use of a topical oil-in-water emulsion composition comprising:

(a) a discontinuous oil phase;

(b) a continuous aqueous phase comprising water and glycerin, wherein the glycerin is present in an amount greater than about 12% by weight, based on the total weight of the composition;

(c) a thickening agent; and

(d) at least one lamellar membrane structure comprising (i) a dialkyl amphiphilic component and (ii) an ester of a branched fatty acid and a branched fatty alcohol; in the manufacture of a lip protectant composition for moisturizing, and protecting, repairing, or restoring the skin lipid barrier of the lips of a mammal.

The invention further provides for the use of a topical oil-in-water emulsion composition comprising:

(a) a discontinuous oil phase;

(b) a continuous aqueous phase comprising water and glycerin, wherein the glycerin is present in an amount greater than about 12% by weight, based on the total weight of the composition;

(c) a thickening agent; and

(d) at least one lamellar membrane structure comprising (i) a dialkyl amphiphilic component and (ii) an ester of a branched fatty acid and a branched fatty alcohol; and

wherein the composition is a lip protectant composition, for moisturizing, and protecting, repairing, or restoring the skin lipid barrier of the lips of a mammal.

The invention further provides for the use of a topical oil-in-water emulsion composition comprising:

(a) a discontinuous oil phase; (b) a continuous aqueous phase comprising water and glycerin, wherein the glycerin is present in an amount greater than about 12% by weight, based on the total weight of the composition;

(c) a thickening agent; and

(d) at least one lamellar membrane structure comprising (i) a dialkyl amphiphilic

component and (ii) an ester of a branched fatty acid and a branched fatty alcohol; (e) at least one UVA sunscreen and at least one UVB sunscreen; and wherein the UVA/SPF protection is about 1 : 1 ; and

wherein the composition is a lip protectant composition, for protecting lips with broad spectrum protection of a UVA and UVB sunscreen, and enriched in UVA protection.

The protection and repair of the skin lipid barrier by the compositions of the present invention improves the skin barrier function and conveys numerous additional therapeutic effects to a mammal to which the compositions are applied.

In one embodiment of the disclosure, the compositions described herein provides moisturization to the lips. Adding the substantial amount of glycerin in the aqueous phase is believed to not render the composition feel tacky or sticky in comparison to other compositions with less glycerin present.

The compositions of the invention are applied to the lips at a frequency consistent with the condition of the lips. For example, where the lips are irritated and in need of repair, more frequent application may be required. Alternatively, where the lips are not irritated and the composition is being applied to merely protect the barrier function of the lips, less frequent application may be possible.

Definitions

The term "applying" as used herein refers to any method which, in sound medical or cosmetic practice, delivers the topical composition to the lips of a subject in such a manner so as to provide a positive effect on a dermatological disorder, condition, or appearance. The compositions are in one embodiment administered such that they cover the entire lips.

As used herein, the phrases an "effective amount" or a "therapeutically effective amount" refers to an amount of a composition or component thereof sufficient enough to have a positive effect on the area of application. Accordingly, these amounts are sufficient to modify the skin disorder, condition, or appearance to be treated but low enough to avoid serious side effects, within the scope of sound medical advice. A therapeutically effective amount will cause a substantial relief of symptoms when applied repeatedly over time. Effective amounts will vary with the particular condition or conditions being treated, the severity of the condition, the duration of the treatment, and the specific components of the composition being used.

The term "effective amount" of a sunscreen is an amount of sunscreen sufficient to provide measurable protection from solar radiation as determined by having a measurable Sun Protection Factor (SPF) value and/or UVA protection value. The term "SPF" (Sun Protection Factor) means the UVB energy required to produce a minimal erythema dose on sunscreen treated skin divided by the UVB energy required to produce a minimal erythema dose on unprotected skin.

As used herein, "treatment" in reference to a condition means: (1) to ameliorate or prevent the condition or one or more of the biological manifestations of the condition, (2) to interfere with (a) one or more points in the biological cascade that leads to or is responsible for the condition or (b) one or more of the biological manifestations of the condition, (3) to alleviate one or more of the symptoms or effects associated with the condition, or (4) to slow the progression of the condition or one or more of the biological manifestations of the condition.

As indicated above, "treatment" of a condition includes prevention of the condition. The skilled artisan will appreciate that "prevention" is not an absolute term. In medicine, "prevention" is understood to refer to the prophylactic administration of a drug to substantially diminish the likelihood or severity of a condition or biological manifestation thereof, or to delay the onset of such condition or biological manifestation thereof.

The phrase "dermatologically acceptable excipient" as used herein refers to any inactive ingredient present in the herein described compositions. Each excipient must be compatible with the other ingredients of the lip protectant composition when commingled such that interactions which would substantially reduce the efficacy of the composition when administered to an individual and interactions which would result in compositions that are not pharmaceutically or cosmetically acceptable are avoided. In addition, each excipient must be of sufficiently high purity to render it pharmaceutically or cosmetically acceptable.

As used herein, a "lip protectant" is a semisolid composition for application to the lips that provides protective, restorative and/or moisturizing properties. These compositions include creams, and lip balms in a stick presentation, as well as soft lip balms such as, for example, those dispensed from jars, pots or tubes.

The term "stick lip balm" means a lip balm that can be formed into a stick that is extensible and retractable from a container and is sufficiently robust to substantially retain the stick shape under typical commercial conditions of shipping, storage and use.

Lip balms are an over-the-counter drug defined as a "drug product that relieves and prevents dryness or chapping of the exposed surface of the lip". Fed Reg. Skin Protectant Drug Products, Final Rules, June 4, 2003 Vol. 68, No. 107, pp3362-3381.

The term "lipstick" means a waxy stick product containing pigment which is transferable to the lips to impart a visible color. Lipsticks may be cosmetics or lip treatments. A lipstick is a lip treatment if, in addition to imparting color, it provides protective and/or moisturizing properties, and/or a beneficial agent and/or a sunscreen and/or a

pharmaceutically active agent to the lips or lip area.

The term "organic sunscreen" means a compound or mixture of compounds that can protect human skin from UVA and/or UVB radiation and is the class of compounds classified by those skilled in the art of chemistry as organic chemicals.

The term "inorganic sunscreen" means a compound or mixture of compounds that can protect human skin from UVA and/or UVB radiation and is the class of compounds classified by those skilled in the art of chemistry as inorganic chemicals. Exemplary inorganic sunscreens include, but are not limited to, zinc oxide and titanium dioxide.

The term "about" means within an acceptable range for the particular parameter specified as determined by one of ordinary skill in the art, which will depend, in part, on how the value is measured or determined, i.e., the limitations of the measurement system. For example, "about" can mean a range of up to 10% of a given value.

As used herein, the phrase "salts thereof refers to salts that are pharmaceutically acceptable. Such salts include: (1) acid addition salts, formed with acids such as, for example, acetic acid, benzoic acid, citric acid, gluconic acid, glutamic acid, glutaric acid, gly colic acid, hydrochloric acid, lactic acid, maleic acid, malic acid, malonic acid, mandelic acid, phosphoric acid, propionic acid, sorbic acid, succinic acid, sulfuric acid, tartaric acid, naturally and synthetically derived amino acids, and mixtures thereof; or (2) salts formed when an acidic proton present in the parent compound is either (i) replaced by a metal ion e.g. an alkali metal ion, an alkaline earth metal ion, or an aluminium ion; or (ii) protonates an organic base such as, for example, ethanolamine, diethanolamine, triethanolamine, tromethamine and N-methylglucamine. "%" as used herein, refers to the percentage by weight of the total composition, unless otherwise specified. All percentages are based on the percent by weight of the final composition prepared unless otherwise indicated and all totals equal 100% by weight.

The term "wt/wt" or "by weight", unless otherwise indicated, means the weight of a given component or specified combination of components to the total weight of the composition expressed as a percentage.

A designation that a substance is a semisolid, should be taken to mean the physical state of the substance in the temperature range of about 20°C to about 40°C.

As used herein, the term "phytosterol" refers to plant sterols and plant stanols. Plant sterols are naturally occurring cholesterol-like molecules found in all plants, with the highest concentrations occurring in vegetable oils. Plant stanols are hydrogenation compounds of the respective plant sterols. Phytosterols are natural components of common vegetable oils.

As used herein, the term "sensitive skin" refers to the degree of skin irritation or skin inflammation, as exemplified by parameters in suitable assays for measuring sensitivity, inflammation or irritation.

It should be understood that the terms "a" and "an" as used herein refers to "one or more" or "at least one" of the enumerated components. It will be clear to one of ordinary skill in the art that the use of the singular includes the plural unless specifically stated otherwise. The term "and/or" as used herein covers both additively and also alternatively the individual elements of a list which are thus linked so that these elements are to be understood as linked selectively with "and" or respectively with "or". Furthermore, the terms used in the singular of course also comprise the plural. Throughout the application, descriptions of various embodiments use "comprising" language, however in some specific instances, an embodiment can alternatively be described using the language "consisting essentially of or "consisting of. "Substantially free" of a specified component refers to a composition with less than about 1% by weight of the specified component. "Free" of a specified component refers to a composition where the specified component is absent. As used herein "mammal" includes, but is not limited to, humans, including pediatric, adult and geriatric patients.

The following examples are illustrative of the present invention and are not intended to be limitations thereon.

Other terms as used herein are meant to be defined by their well-known meanings in the art.

It should be noted that the present formulations do not include as a necessary excipient a traditional surfactant. As such this is meant to mean anionic, cationic, non-ionic and zwiterionic surfactants. Traditional anionic surfactants include ammonium lauryl sulfate, sodium lauryl sulfate (sodium dodecyl sulfate, SLS, or SDS), and the related alkyl-ether sulfates sodium laureth sulfate (sodium lauryl ether sulfate or SLES), docusate (dioctyl sodium sulfosuccinate), perfluorooctanesulfonate (PFOS), alkyl-aryl ether phosphates and alkyl ether phosphates. Traditional cationic surfactants include cetrimonium bromide (CTAB), cetylpyridinium chloride (CPC), and benzalkonium chloride (BAC). Traditional zwiterionic surfactants include cocamidopropyl hydroxy sultaine, and cocamidopropyl betaine. Traditional non-ionic surfactants include polyethylene glycol alkyl ethers (such as Brij); polypropylene glycol alkyl ethers; glucoside alkyl ethers, such as decyl glucoside, lauryl glucoside, and octyl glucoside; polyethylene glycol octylphenyl ethers, such as Triton X-100; polyethylene glycol alkylphenyl ethers, such as Nonoxynol-9; Glycerol alkyl esters, such as glyceryl laurate; polyoxy ethylene glycol sorbitan alkyl esters, such as the polysorbates; the sorbitan alkyl esters, such as the spams; and the block copolymers of polyethylene glycol and polypropylene glycol, e.g. the poloxamers.

EXAMPLES

Example 1 - Lip protectant composition

A lip protectant composition having the following formulation illustrates the invention:

The composition is prepared in two key steps. In the first step, a blend (pastilles) having the lamellar membrane structure* composition is prepared. The pastilles are formed by, for example, combining behenic acid, cetyl alcohol, isostearyl isostearate, cetyl behenate and dicetyl phosphate to form a blend. The blend is neutralized with potassium hydroxide, the residual water removed and then the blend pastillated to form pastilles. The lamellar membrane blend is available as a pastillated and/or flaked product from Croda

International PLC. In a second step, the blend is added to the composition during the formulation of an oil-in- water emulsion to give the final composition as follows:

Phase 1 (Aqueous):

18.29% by weight Water

0.20% by weight Caprylyl glycol

12.00% by weight Glucose monohydrate

0.20% by weight Dehydroxanthan gum

20.67% by weight Glycerin

1.85% by weight NaOH (10% w/w)

I .00% by weight Capryloyl glycine

Phase 2 (Oil):

7.50% by weight Butyrospermum parkii butter

2.50% by weight Behenyl alcohol

0.10% by weight VP/eicosene copolymer

I I .10% by weight Diethylhexyl syringylidene malonate / caprylic/capric triglyceride 2.78% by weight Butyl methoxydibenzoylmethane

0.01 % by weight Ascorbyl palmitate

4.55% by weight Ethylhexyl salicylate

Phase 3 (Thickening):

7.00% by weight 01 us (vegetable) oil

0.05% by weight Sodium carbomer

0.05% by weight Acrylates/C 10-30 alkyl acrylate crosspolymer

Phase 4 (Lamellar membrane structure component):

0.10% by weight Tocopherol

0.05% by weight Trisodium ethylenediamine disuccinate

10.00% by weight lamellar membrane structure blend

Phase 1 and Phase 2 are first heated to 83 °C (+/- 3deg C) for production. Phase 2 is then slowly added to Phase 1 and the mixture is continuously stirred. The combined Phases are then homogenized for a minimum of 5 minutes at 15000 RPM with a hand held homogenizer. The combined phases are allowed to cool to 65°C with continuous stirring. Phase 3 is then added to the combined Phases 1 and 2 and mixed for a minimum of 5 minutes. The combined Phases (1, 2, and 3) are then cooled to 35°C with continuous stirring in a water bath. Phase 4 is then added to Phases 1, 2, and 3 with continuous stirring. The mixture is then homogenized again for a minimum of 10 minutes at 12000 RPM. The lip protectant composition thus produced is deaerated and allowed to rest overnight prior to further analysis. (Note: the deaeration step is required for small scale manufacture since the system is not under vacuum and so air can be beaten into the system and affect the ability of emulsifiers to orientate in oil/water vs air/water. Removal of the air creates a system similar to that produced on the larger scale mixer such as a Beko mixer).

Using the following experimental protocols the formulations of the present invention maybe tested for their ability to protect against UV -induced DNA or tissue damage, apoptosis and inflammation. Example 2 - Determining the protective activity against UVB-induced DNA damage, apoptosis and inflammation using reconstructed human epidermis (EpiDerm)

Upon receipt, reconstructed human epidermis (EpiDerm, EPI-200, made of normal human epidermal keratinocytes, MatTek, Ashland, MA) are placed into media (EPI-100-ASY, 1.0 ml/well of 6-well plates) and incubated overnight at 37°C / 5% CC . The media is replenished with fresh culture media prior to study. A lip balm formulation with UV filters (Invention) and one without UV filters (placebo) are applied topically (2 and 10 mg/cm ² , using positive displacement pipette tip for formulation) and then gently massaged into the skin equivalents (-20 rotations) using the rubber side of a plunger of 1 ml syringe.

Distilled H ₂ 0 serves as an untreated control, and distilled H ₂ 0 plus UVB irradiation serves as a UVB control. After 1 hour pre-treatment with lip balm formulations, the EpiDerm tissues are transferred to a sterile 6-well plate containing 1 ml of DPBS per well and then exposed to UVB at 150 mJ/cm ² . The Newport Solar Simulator System (Power unit 69920, and Lamp 91192-1000, Newport Corporate, Irvine, CA) is used as the UVB emitter to achieve a UVB irradiation of 150mJ/cm ² . Measurement of the irradiation is taken using an ILT-1400 Handheld, Portable Radiometer /Photometer (International Light Technologies, Inc., Peabody, MA) with a UVB detector (SEL240/T2ACT5, 235 - 307 nm, International Light Technologies, Inc.). After UVB irradiation, EpiDerm tissues are transferred back to the 6-well plate containing media and incubated at 37°C/5% CO2 for 6 hours. At the end of the incubation (6 hr post UVB irradiation), culture media is collected for the measurement of IL-6, IL-8, and TNF-a concentration by MagPix (Millipore,

HCYTOMAG-60K) and PGE ₂ concentration by ELISA (R&D Systems, SKGE004B). The EpiDerm tissues are harvested and placed in 10% formalin for histological processing including paraffin embedding, sectioning, immunohistological analyses of DNA damage (cyclobutane pyrimidine dimers, CPDs) and apoptosis (cleaved caspase-3, CC3).

Example 3 - Determining the protective activity against UVB-induced DNA damage, apoptosis and inflammation using gingival oral equivalents (EpiGingival)

Gingival oral mucosal equivalents (EpiGingival, GIN- 100, MatTek, Ashland, MA) use normal human oral keratinocytes (NHOK) to differentiate into tissues with a comified, gingival phenotype. Therefore, EpiGingival might better replicate the characteristics of lip skin and will be used to evaluate the photoprotective effect of lip balm formulations. Upon receipt, EpiGingival equivalents are placed into media (GIN-100-MM, 1.0 ml/ well of 6- well plates) and incubated overnight at 37°C / 5% CO2. The media is replenished with fresh culture media prior to study. The lip balm with SPF (Invention) and without SPF (placebo) are applied topically (~4 mg/cm ² , using positive displacement pipette tip for formulation) and then gently massaged into the skin equivalents (-20 rotations) using the rubber side of a plunger of 1 ml syringe. Distilled H ₂ 0 serves as an untreated control, and distilled H ₂ 0 plus UVB irradiation serves as a UVB control. After 1 hr pre-treatment with lip balm formulations, the EpiGingival tissues are transferred to a sterile 6-well plate containing 1 ml of DPBS per well and then exposed to UVB at 150 mJ/cm ² as described in Example 2. After UVB irradiation, EpiGingival tissues are transferred back to the 6-well plate containing media and incubated at 37°C/5% CO2 for 6 hours. At the end of the incubation (6 hr post UVB irradiation), culture media is collected for the measurement of 11-6, IL-8, and TNF-a concentration by MagPix (Millipore, HCYTOMAG-60K) and PGE ₂ concentration by ELISA (R&D Systems, SKGE004B). The EpiGingival tissues are harvested and placed in 10% formalin for histological processing including paraffin embedding, sectioning, immunohistological analyses of DNA damage (cyclobutane pyrimidine dimers, CPDs) and apoptosis (cleaved caspase-3, CC3).

Example 4 - Determining the protective activity against UVA-induced DNA damage, apoptosis and inflammation using Full thickness skin equivalents (EpiDerm ^FT )

EpiDerm ^FT System consists of normal, human-derived epidermal keratinocytes and dermal fibroblasts which have been cultured to form a multilayered, highly differentiated model of the human dermis and epidermis. As used herein, EpiDerm ^FT refers to full thickness epidermal equivalents. EpiDerm ^FT (EFT-400, MetTek) will be used for the assessment of UVA-induced skin damage and photoprotective activity of lip balm formulations. Upon receipt, EpiDerm ^FT is placed into media (EFT-400-MM, 1.0 ml/well of 6-well plates) and incubated overnight at 37°C / 5% CO2. The media is replenished with fresh culture media prior to study. The lip balm with SPF (Invention) and without SPF (placebo) are applied topically (10 mg/cm ² , using positive displacement pipette tip for formulation) and then gently massaged into the skin equivalents (-20 rotations) using the rubber side of a plunger of 1 ml syringe. Distilled H ₂ 0 serves as an untreated control, and distilled H ₂ 0 plus UVA irradiation serves as a UVA control. After 1 hr pre-treatment with lip balm formulations, the EpiDerm ^FT tissues were transferred to a sterile 6-well plate containing 1 ml of DPBS per well and then exposed to UVA at 30-50 J/cm ² as indicated. The Newport DS-101103 UV Solar Simulator with UV-A-F filter (Sol-UV-A-F ) (Newport Corporate) is used as the UVA emitter to achieve a UVA irradiation of 30-50 J/cm ² . Measurement of the irradiation is taken using an ILT-1400-A radiometer/photometer with a UVA probe (SSL001 A, international light technologies, Inc.).

After UVA irradiation, EpiDerm ^FT tissues are transferred back to the 6-well plate containing media and incubated at 37°C/5% CO2 for 6 hours. At the end of the incubation (6 hr post UVA irradiation), culture media is collected for the measurement of IL-8, and TNF-a concentration by MagPix (Millipore, HCYTOMAG-60K) and PGE ₂ concentration by ELISA (R&D Systems, SKGE004B). The EpiDerm ^FT tissues are harvested and placed in 10% formalin for histological processing including paraffin embedding, sectioning, immunohistological analyses of DNA damage (8-hydroxy-2' -deoxyguanosine, 80HdG) and apoptosis (cleaved caspase-3, CC3). Example 5 - Determining the protective activity against UVA-induced tissue damage using gingival mucosal equivalent (EpiGingival)

Gingival oral mucosal equivalents (EpiGingival, GIN- 100, MatTek, Ashland, MA) are used for the assessment of the protective effect of a lip balm formulation against UVA radiation. The gingival equivalents were maintained as described in Example 4. The lip balm with UV filters (Invention) and without UV filters (placebo) are applied topically (~4 mg/cm ² , using positive displacement pipette tip for formulation) and then gently massaged into the skin equivalents (-20 rotations) using the rubber side of a plunger of 1 ml syringe. After 1 hr pre-treatment with lip balm formulations, the EpiGingival tissues are transferred to a sterile 6-well plate containing 1 ml of DPBS per well and then exposed to UVA at 30- 50 J/cm ² as described in Example 4. Sham irradiated EpiGingival equivalents are used as sham control. After UVA irradiation, EpiGingival equivalents are transferred back to the 6-well plate containing media and incubated at 37°C/5% CO2 for 28 hours. At the end of the incubation (28 hr post UVA irradiation), culture media are PGE ₂ concentration by ELISA (R&D Systems, SKGE004B). The EpiGingival equivalents are harvested and placed in 10% formalin for histological processing including paraffin embedding, sectioning, immunohistological analyses of DNA damage (8-hydroxy-2' -deoxyguanosine, 80HdG) and apoptosis (cleaved caspase-3, CC3). EpiGingival equivalents are also pretreated with lip balm with UV filters for 1 hr, then irradiated with UVA at 30 J/cm2, followed by UVB radiation at 150 mJ/cm ² .

Example 6 - Determining the Tackiness of a Formulation

There are various methods available to measure tackiness or stickness of a formulation. Two accepted Tack Test methods include the Probe Tack Method and the Rolling Ball Method as both defined in the Unites States Pharmacopeial Convention, Interim Revision Announcement, November 1, 2013 whose disclosure is incorporated herein by reference.

A variation of the Probe Tack Method uses a Malvern Kinexus Rheometer to Measure Tackiness. The Basic Method Parameters, which may be modified as needed are:

• sample set gap between plates: 0.15mm

• compression force: 19N

• pause time after compression before pull up: 0.5sec

• geometry type: 40mm/4deg rough cone with rough lower plate to model finger surfaces

Procedure

1. Add approx 1.5-2mL to the lower rheometer geometry plate. One consideration is whether or not to apply to sample to the plate as if it were applied to skin or with minimal manipulation. The process of pumping, scooping, spreading etc. may modify the rheological and sensorial properties of the sample. 2. Initiate rheometer pull-away method in software

Rheometer lowers upper cone to compress sample to 0.15mm target gap, waits 0.5 sec and then quickly pulls away from sample while measuring force vs time to generate a plot.

3. Report the area under the curve (AUC) and/or the force (Newtons) from baseline to maximum.

All publications, including but not limited to patents and patent applications, cited in this specification are herein incorporated by reference as if each individual publication were specifically and individually indicated to be incorporated by reference herein as though fully set forth.

The above description fully discloses the invention including preferred embodiments thereof. Modifications and improvements of the embodiments specifically disclosed herein are within the scope of the following claims. Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. Therefore, the Examples herein are to be construed as merely illustrative and not a limitation of the scope of the present invention in any way. The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows.