LIST, Robin (Boerestraat 13, Hansbeke, B-9850, BE)
1. A topical skin care composition for scar treatment, wherein the composition comprises at least one polysiloxane film forming agent and at least further one film forming agent.
2. The composition according to claim 1 , wherein the film forming agent includes at least one vinyl polymer.
3. The composition according to claim 2, wherein the vinyl polymer comprises polyvinylpyrrolidone (PVP) and polyvinylalcohol (PVA) and mixtures thereof.
4. The composition according to claim 3, wherein the concentration of the vinyl polymer varies from 0.1 - 10.0 wt. %, preferably 0.1-5.0 wt. %, more preferably 0.5-2.5 wt. %.
5. The composition according to any one of claims 1-4, wherein the composition further comprises at least one beta- glucan, preferably a β-(1 , 3)-glucan.
6. The composition according to claim 5, wherein the concentration of the at least one β-glucan ranges from 2.5 to 15.0 wt. %, preferably from 5.0 to 12.5 wt. %. A suitable concentration may vary around 10.0 wt. %.
7. The composition according to any one of claims 1 -6, wherein the polysiloxane comprises a mixture containing at least two polysiloxanes selected from the group of a cyclic polysiloxane and an organic modified linear polysiloxane.
8. The composition according to any one of claims 1-7, wherein the polysiloxane is selected from the group of a cyclic polysiloxane, a linear alkylpolysiloxane copolyol and a mixture of two or more of these compounds.
9. The composition according to claim 8, wherein the cyclic polysiloxane is contained in a concentration which varies from 20.0- 60.0 wt. % with respect to the total weight of the composition, preferably 25.0- 50.0 wt. %, more preferably 30.0-45.0 wt. %.
10. The composition according to claim 8, wherein the linear alkylpolysiloxane copolyol is contained in a concentration which varies from 2.0-20.0 wt. % with respect to the total weight of the composition, preferably 2.0-15.0 wt. %, more preferably 5-12.5 wt. %.
11. The composition according to any one of claims 1-10, wherein the composition further contains at least one UV- protecting agent.
12. The composition according to claim 11 , wherein the UV protecting agent is selected from the group of UV-A and UV-B protecting agents or a mixture thereof.
13. The composition according to any one of claims 1-7, wherein the UV protecting agent is selected from the group of 1-(4- tert.butylphenyl)-3-(4-methoxyfenyl)-propane-1 ,3-dione, 4-tert-butyl-4- methoxydibenzoyl methane, 1 -phenyl-3-(4-isopropylfenyl)-propane-1 ,3dione, 4- methylbenzyllidenecamphor, 2-phenyl-benzimidazole-5-sulfonic acid, octyl methoxycinnamate, octyl salicylate, octycrylene benzophenone-3 homosalate, octocrylate, avobenzon, menthyl anthranilate, and 2-ethyl-hexyl-p- methoxycinnamate one or more inorganic particulate materials selected from the group of zinc oxide, silica, iron oxide, titanium dioxide, and mixtures of two or more of these materials.
14. The composition according to claim 12, wherein the UV-protecting agent comprises a mixture of particulate titaniumdioxide and avobenzon.
15. The composition according to any one of claims 1-13, wherein the composition comprises at least one additive selected from the group of fats, fatty alcohols and fatty acids, oils, liquid ester oils, waxes, humectants emulsifiers, anionic surfactants, preservatives, water and a mixture of two or more hereof.
16. Kit for treating scar tissue comprising the topical composition according to any one of claims 1-14, and an applicator for applying the topical composition on scar tissue.
17. Kit according to claim 15, wherein the applicator takes the shape of a stick which contains the topical composition.
18. Method for treating scar tissue, wherein the topical composition according to claims 1-14 is applied as a film to the scar tissue.
19. Method according to claim 17 wherein the topical composition according to any one of claims 1-14 is applied to the scar tissue, using the kit according to claim 15 or 16.
The present invention relates to a topical skin care composition for the treatment of scars.
The present invention also relates to a kit for treating scar tissue comprising the topical skin care composition, and an applicator for applying the topical composition on scar tissue.
Scars are areas of fibrous tissue replacing normal skin or other tissue after injury or disease, as an expression of the natural healing process of the injured skin or tissue. In general two types of scars seem to be most abundant, in particular hypertrophic and keloid scars. Hypertrophic scars occur usually in areas of thick skin, in the form of raised, red, nodular lesions within the boundaries of the original wound, characterized by hypervascularity, which is responsible for their erythematous appearance. Keloid scars on the other hand mostly have a genetic ethiology. The size and shape of keloids have little correlation to the extent of the skin wound, and keloids may grow to form big boney tumours. Other types of frequently occurring scars include contracture scars caused by the loss of a large section of skin following e.g. burns or other injury, where the scars contract or tighten around the wound and that way impact the patient's mobility - and acne scars which may form as a result of severe acne, a skin condition usually caused by hormonal changes.
Wound-healing is a complex, tightly regulated process of wound repair, which comprises an inflammation phase, a proliferation phase and a maturation phase. Release of cytokines from the injured tissue cells and wound blood clot initiates the inflammatory phase. The proliferation stage is characterised by cascading coagulation wherein an increasing number of fibroblasts with increasing density is released for the synthesis of extracellular matrix and collagen. As soon as sufficient provisional matrix is generated, the final the maturation stage is initiated. The maturation stage is characterized by a shift in balance from scar remodelling towards scar degradation and is accompanied by extracellular matrix reorganization and reduction. The pathophysiologic mechanisms leading to keloid or hypertrophic scar formation are still unknown, although many different theories have been proposed. Position of the injury and ethnic background may predispose a patient to the development of keloid or hypertrophic scars, besides other parameters.
Every year, millions of injured patients become affected by keloid and hypertrophic scar formation. It is estimated that about 80% of the population has one or more scars. The incidence of hypertrophic scars following surgery is said to be about 40-70%, whereas it is higher (up to 91%) following burn injury. Although hypertrophic and keloid scars may develop at any age, patients between 10 and 30 years old seem to be most often affected. It may be true that the presence of scars is not life-threatening and affects the functioning of the human body in a small number of cases only, nevertheless their psychological impact on the human well-being may not be underestimated.
A wide variety of treatment methods and agents has been developed, which aim at masking or covering scars or reducing their visibility. Unfortunately none of the techniques developed to date permits achieving permanent scar removal. Surgical excision of the scar in combination with steroids and/or silicone treatment are associated with frequent scar recurrence. Scars older than 6-12 months seem to respond poorly to pressure therapy, the pressure dressing is moreover sensed as uncomfortable by the patient. Other treatments include radiation therapy, laser therapy, cryotherapy, intralesional administrateion of corticosteroids and topical application of steroid creams. Cosmetic creams and ointments based on gel technology which aim at hydrating and/or masking scars, provide a limited physical barrier only when applied to scar tissue. As a result, their effect in scar healing and reduction is limited as well.
More recently developed methods aiming at improving the signs and symptoms of scars and at preventing the development of abnormal scarring, include topical silicone therapy in particular topical application of silicone gels and silicone gel sheets. Silicones may soften, smoothen and flatten scar tissue, they may assist in reducing itching and light pain, they are suitable for use with both keloid and hypertrophic scars. Silicones are appreciated for their humidifying properties and their ability to act as a carrier for other active ingredients e.g. UV-protectors, anti-microbiol agents and humectants. The use of silicone gel is well accepted by patients because the sheet formed by it is nearly invisible sheet and dries fairly quickly when applied correctly in a thin layer. The use of silicone sheets poses several limitations, in particular because application to certain body parts and to large areas or near joints as well as use on the face or other areas where the contours or motility of the skin make it difficult to ensure adequate contact and coverage, may be difficult. Silicone sheets must be washed carefully and sufficiently often to prevent infection. A major downside of silicone gel sheeting is the fact that the sheet adheres to the skin. Frequent removal may cause removal of varying amounts of superficial stratum corneum and skin stripping in the normal skin adjacent to the wound, leading to changes in the skin barrier function, in particular increased transepidermal water loss. An inflammatory skin reaction may develop in the skin adjacent to the wound.
US2009/0143333 A1 discloses a composition which may take the form of a silicone gel that dries to a thin film on the skin. The composition is non-viscous, it may be easily spread. The composition comprises a cyclic siloxane, to provide fluidity and a smooth and pleasant texture, enabling the convenient application of a thin film to leave the remaining components in the form of a thin occlusive film on the skin. The composition further comprises a silicone occlusive fluid, a silicone occlusive gel, a silicone resin powder and preferably a ascorbic acid fatty acid ester or a salt thereof. The non-volatile occlusive fluid and gel provide a flexible moisture barrier that is adhesive to the skin. The silicone resin powder acts as film-forming agent and ensures that the barrier produced upon evaporation of the cyclic siloxane has a relatively dry, smooth feel. The ascorbate ester may be absorbed by the endothelial cells and provide an anti-oxidant function. Although these silicone based products have a clear clinical effect which is more pronounced than that of common creams and ointments, they nevertheless show several disadvantages. In particular, because of the limited topical adhesion, the film may easily be removed from the scar and the surrounding skin by slight rubbing, or it may slide from the scar. The composition has been found to provide only a limited physical barrier, and to remain humid even after drying. Application of the composition is done manually and entails a risk to cross- contamination and/or infection of the scar when applied with contaminated hands.
The known compositions and methods for reducing the appearance of scars which make use of silicones present the additional disadvantage that their healing activity is limited, as their major effect is based on the effect of silicone only.
There is thus a need to a skin care composition which is suitable for treating scars, in particular for healing scars in a way which permits to reduce their visibility and expression, which shows an improved and more complete healing activity as compared to the products known from the prior art.
It is therefore the object of the present invention, to provide a skin care product which is capable of healing and/or repairing scars in a way which permits to reduce the visibility and expression of the scars.
In particular, it is an object of this invention to provide a skin care product which is capable of providing an integral scar treatment in a way which reduces the visibility and expression of the scars.
This problem is solved according to the invention with a product showing the technical features of the characterising portion of the first claim.
Thereto, the topical skin care composition for the treatment of scars of this invention is characterised in that it comprises at least one polysiloxane and at least one further film forming polymer.
With "film-forming polymer" is meant a polymer which upon application of the product on the scar tissue, tissue or skin, ensures formation of a continuous film of the product which is adhesive to the tissue, skin or scar tissue.
Most polysiloxanes show good lubricating properties and a limited ability to penetrate scar and/or skin tissue. As a result of the presence of polysiloxanes, sliding or rubbing of the composition of this invention over the skin and scar tissue is facilitated and therewith application of the composition, certainly if the composition is applied using a slight pressure. The incorporation of a further film forming polymer ensures that upon application of the composition, material released from the composition creates an adhering, occlusive film on top of the skin and/or scar tissue. The cohesion of the composition is such that adhesion to skin and scar tissue is advantageous.The excellent lubricating and film forming properties render the composition of this invention particularly suitable for use in the form of a stick, where the composition is applied by rubbing the stick over the skin. Topical application of the composition of this invention creates a smooth feeling of the skin and scar tissue. This effect is mainly attributed to the presence of the polysiloxane in the formulation, which softens the texture of the composition. Smoothening is believed to enhance scar repair, certainly when used in combination with further ingredients. The film will usually disappear over time due to erosion, but it may also be removed using a dedicated detergent. Thus, the risk to skin stripping which has been found to adversely affect scar repair, may be minimized.
The composition of the present invention comprises at least one polysiloxane film forming agent. Examples of polysiloxane compounds suitable for use with this invention include polymeric or oligomeric compounds, the polysiloxane may be organically modified. The polysiloxanes may be cross-linked if so desired. Mixtures of two or more different polysiloxanes may be used as well. Polysiloxanes are contained in the composition of this invention for their remarkable film forming properties.
Within the scope of the present invention a wide range of further film forming agents may be used. Particularly suitable film forming agents include homo- or co-polymers of vinyl compounds. The vinyl film-forming polymers may result from the homopolymerization or copolymerization of monomers chosen from the group of vinyl alcohol, vinyl esters such as vinyl acetate, neodecanoate, vinyl pivalate, vinyl benzoate, vinylpyrrolidon and vinyl t- butyl benzoate, vinyl and styrene monomers such as styrene and alpha-methyl styrene. The vinyl film-forming polymers may include polymers obtained by co-polymerization of ethylenically unsaturated monomers having at least one alcohol or acid group and/or esters of these acidic monomers and / or amides of these acidic monomers such as for example unsaturated carboxylic acids, alpha, beta - for example ethylene acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid. Other suitable film forming polymers include polyurethanes, polyesters, polyester amides, polyamides, and polyureas.
Vinyl polymers are usually water soluble organic polymers, with good emulsifying properties and good compatibility with polysiloxanes which facilitates their incorporation in polysiloxane containing formulations. Vinyl polymers generally show good film forming and good adhesive properties to skin tissue, other human tissue and scar tissue. Their adhesive and film forming properties and the limited ability of vinyl polymers to penetrate scar tissue, tissue and skin have the effect that application of the composition of this invention will result in the formation of an occlusive polymer film on top of the scar tissue, which film comprises the vinyl polymer and the polysiloxane. The polymer film provides a mechanical protection and an occlusive barrier capable of limiting penetration of foreign materials through the film towards the scar tissue. Therewith micro environmental conditions are created within the polymer film around the scar tissue, capable of stimulating and often accelerating scar tissue repair. These micro-conditions have been found to occur through application of the product as such, without the need to incorporate further active ingredients. Because the film will usually disappear over time due to erosion and may be removed using a dedicated detergent, the risk to skin stripping which has been found to adversely affect scar repair, may be minimized. These effects are particularly pronounced when PVP, PVA, copolymers thereof or mixtures thereof are used as further film forming polymers.
Therefore, particularly suitable film forming polymers for use with the present invention include polyvinylpyrrolidone (PVP) and polyvinylalcohol (PVA), copolymers of these and mixtures of two or more of these polymers. These polymers find numerous applications in cosmetic formulations for topical application. The vinyl polymer may be used as a powder or as an aqueous solution.
The concentration of the vinyl polymer in the composition of the present invention will usually vary from 0.1 - 10.0 wt. %, preferably 0.1 -5.0 wt. %, more preferably 0.5-2.5 wt. %.
If so desired, the film forming polymer may comprise an auxiliary film-forming agent to further improve film formation.
The polysiloxane used in the composition of this invention may for example be selected from linear siloxanes, in particular linear alkyl or aryl siloxanes, branched siloxane, cyclic siloxanes and silicone copolymers.
Linear polysiloxanes will usually respond to formula I below :
R 3 -Si-0 - [SiR 2 ] n -SiR 3 (formula I)
- n will usually vary from 1 to about 15.000, but preferably from 20-7000.
- R will usually be selected from one or more of linear, branched or cyclic alkyl groups containing 1 to 20, preferably 1-16 carbon atoms, aryl substituents such as phenyl, naphthyl, substituted phenyl, or substituted naphthyl, a siloxane chain so as to give a branched silicone, hydrogen, or vinyl groups. In addition, substituents R may also contain further functional groups attached to carbon such as one or more of alkenyl, alkynyl, carboxyl, hydroxy, acrylate, ester, ether, alkoxy, halogen, cyano, mercapto, amino and carbohydrate groupings. In a practical example R may be derived from a fatty acid.
The siloxane may contain terminal OH groups, the so-called "siliconol" materials. The R group in commercially available siloxanes will usually predominantly be methyl.
Examples of linear polysiloxanes suitable for use with this invention include hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, phenyl trimethicone and dimethicones. Examples of other suitable linear siloxanes include those where at least part of the R groups are selected from a polyol, a polyether, a polyester, a radical containing one or more epoxy groups.
The linear polysiloxane used in the composition of this invention will usually have a molecular weight which ranges from 10000 to 10000000 g/mol.
Linear polysiloxanes, in particular those which are organically modified for example with a polyol or polyether, are appreciated for their transparency, their film forming and visco-elastic properties. This is of particular importance where the composition of this invention takes the form of a stick and is applied by rubbing the stick over the skin - scar tissue to leave a film thereon.
Linear polysiloxanes will usually be present in a concentration which ranges from 2.0-20.0 wt. % with respect to the total weight of the composition, preferably 2.0-15.0 wt. %, more preferably 5-12.5 wt. %.
Cyclic siloxanes which may be employed in the present invention include, but are not limited to, those of general formula II
(Formula II) wherein
R is independently selected from an alkyl group consisting of 1 to 10 carbon atoms, an aryl group consisting of 6 to 10 carbon atoms, hydrogen and vinyl;
and p is from 3 to 10.
Where R is CH 3 , p will usually be at least 4, preferably at least 5. Preferably R is CH 3 and p is 5, i.e. decamethylcyclopentasiloxane. These products are appreciated for their emulsifying properties and that way they assist in providing a homogeneous, stabile emulsion of all ingredients. Cyclic polysiloxanes in particular decamethyl-cyclopentasiloxane are further appreciated for their transparency and their ability to act as a skin conditioning agent, as a result of which scar repair may be stimulated. Besides this, cyclic polysiloxanes in particular decamethylcyclo-pentasiloxane are appreciated for their lubricating properties, which smoothens application of the composition of this invention to the scar tissue and skin, facilitates application by rubbing and improves spreading. This is of particular importance where the composition of this invention takes the form of a stick, and where the composition is applied by rubbing the stick over the skin - scar tissue.
The cyclic polysiloxanes are usually present in a concentration which varies from 20.0-60.0 wt. % with respect to the total weight of the composition, preferably 25.0-50.0 wt. %, more preferably 30.0-45.0 wt. %. The cyclic polysiloxane will usually be present in an excess compared to the organic modified linear polysiloxane.
A preferred embodiment of the composition of this invention may be characterised in the siloxane compound used in the composition of this invention is selected from the group of dimethicone, stearyl methyl-dimethyl siloxane copolymers, Polysilicone-11 (a cross-linked silicone obtained by reaction of a vinyl terminated silicone en (methylhydrodimethyl) polysiloxane in the presence of cyclomethicone), cetearyl dimethicone/vinyl dimethicone cross- polymers (a copolymeer of cetearyl dimethicone cross- linked with vinyl dimethyl polysiloxane), dimethicone/phenyl vinyl dimethicone cross-polymer (a copolymer of dimethylpolysiloxane cross-linked with phenylvinyldimethylsiloxane), and dimethicone/vinyl dimethicone cross- polymer (a copolymer of dimethylpolysiloxane cross-linked with vinyldimethylsiloxane).
Most preferably the composition of this invention comprises a mixture containing at least two polysiloxanes, in particular a mixture of a cyclic polysiloxane and an organic modified linear polysiloxane as described above. The presence of the above-described polysiloxanes in the composition of this invention in the appropriate amounts in an admixture with at least one further film forming agent, preferably a vinylpolymer, ensures that the composition of this invention shows sufficient consistency to be suitable for use in the form of a stick, that the composition has excellent lubricating properties to facilitate application on scar tissue and that the composition shows good film forming properties so that a closed film may be formed on the skin and/or scar tissue.
Preferably, the composition of this invention comprises at least one beta glucan, in particular a p-(1 ,3)-glucan. A glucan is a polysaccharide consisting of D-glucose monomers, with the six-sided D- glucose rings connected at the 1 and 3 positions. The p-(1 ,3)-glucan used in this invention may contain a number of 1 ,6 linkages in the longer beta-1 ,3 glucan backbone. These are usually referred to as beta-1 ,3/1 ,6 glucans and are well known organic compounds. Because of their high molecular weight, β- glucans do virtually not penetrate into the skin but rather form an occlusive barrier over the skin, β-glucans have been fount to exhibit a strong moisturizing effect. The combination of their occlusive barrier properties and moisturizing effect result in strong wound healing properties and their ability to stimulate scar repair and reduction. Besides this, the inventors have observed that when β-glucan, in particular p-(1 ,3)-glucan is used in combination with PVP and/or PVA in a composition, a synergistic effect is obtained. Thereby not only the film forming properties of the composition are found to improve, but a film may be obtained with stronger mechanical properties in particular a film with improved flexibility, improved stretching ability and an improved resistance to tearing apart or crack formation.
The concentration of the p-(1 ,3)-glucan in the composition of this invention may vary within wide ranges, but preferably ranges from 2.5 to 15.0 wt. %, preferably from 5.0 to 12.5 wt. %. A suitable concentration may vary around 10.0 wt. %.
The present invention thus provides a composition which is capable of providing multi-effect scar treatment. In particular, application of the composition is facilitated due to improved lubricating properties ; an occlusive film may be formed on top of the scar and/or skin tissue which creates an at least temporary micro-climate or micro- conditions which stimulate scar repair by reducing moisture loss through the scar tissue to a minimum and stimulating tissue repair by softening the scar tissue through the presence of the polysiloxane ; the occlusive film forms a mechanical barrier with improved mechanical properties, i.e. improved resistance towards breaking or cracking and improved flexibility. Therefore, the composition of this invention is suitable for use with virtually all body parts, also those which are difficult to reach, which contain a lot of plies or have a large surface. The film may be easily removed at minimum risk to skin stripping. The composition of this invention herewith provides a broad, though concentrated approach which permits to achieve an accelerated repair of scar tissue.
The composition of this invention further preferably comprises a UV protecting agent, more preferably a protecting agent selected from the Group of UV-A and UV-B protecting agents or mixtures thereof. The inventors have observed that scars are extremely sensitive to irradiation by sun-light and in particular to irradiation by UV-light. Due to the incorporation of at least one UV-protecting agent, the risk to further damage and irritation of existing scar tissue which would slow down their repair, and damage of newly repaired tissue by the ever present UV-irradiation may be limited. Incorporation of at least one UV-protecting agent further permits minimising the risk to the formation of irreversible, visible scars on top of the existing scars. As a result, the composition of the present invention is capable of enhancing and often accelerating repair of scar tissue.
The UV-protecting agent is preferably selected from the group of 1-(4-tert.butylfenyl)-3-(4-methoxyfenyl)-propane-1 ,3-dion, 4- tert-.butyl-4-methoxydibenzoyl methane, 1 -phenyl-3-(4-isopropylphenyl)- propane-1 ,3dion, ,4- methylbenzyllidenecamphor, 2-fenyl-benzimidazole-5- sulfonic acid, octyl methoxycinnamate, octyl salicylate, octycrylene benzophenone-3 homosalate, octocrylate, avobenzon, and menthyl anthranilate, inorganic particulate materials, zinc oxide, silica, iron oxide, titanium dioxide and 2-ethyl-hexyl-p-methoxycinnamate, avobenzone, and mixtures of two or more of these components. Examples of oil soluble UV-A filters include 1-(4-tert.butylphenyl)-3-(4-methoxyfenyl)-propane-1 ,3-dion, 4- tert-.butyl-4-methoxydibenzoyl methane and 1-fenyl-3-(4-isopropylphenyl)- propane-1 ,3dion. Examples of UVB-filters include octylmethoxycinnamate, octycrylene, 4- methylbenzyllidenecamphor, 2-phenyl-benzimidazole-5-sulfonic acid, octyl salicylate, zinc oxide, titaniumoxide, iron oxide. Preferably, in the composition of this invention use is made of micronised titaniumdioxide which provides UV-A as well as UV-B protection. Penetration of UV radiation impinging the skin or scar tissue (290- 370nm) is blocked because the UV-light dispersing and reflecting properties of the titaniumdioxide particles. The titaniumdioxide particles may be transparent to light with longer wavelength. More preferably, the composition of this invention comprises a mixture of micronized titaniumdioxide and avobenzone (4-tert-.butyl-4-methoxydibenzoyl methane). Avobenzone is an oil soluble UV-A protective agent capable of blocking a large UV-A spectrum (310-400-nm).
In a preferred embodiment, the composition of the present invention further comprises one or more additives, which permit to provide the composition in the most appropriate galenic form.
These additives may for example be selected from the group of fats, fatty alcohols and fatty acids, waxes and oils, humectants and skin conditioning products, emulsifiers, surfactants, preservatives, water and mixtures of two or more thereof.
From the group of fats for example triacylglycerols may be used, or in other words triple esters of fatty acids with glycerol. The esters may contain saturated or unsaturated fatty acids, which may be branched or not. The fatty acids may either be used as such or they may be subjected to a partial or full hardening. The esters may be esters containing one single fatty acid, but they may also be mixed esters of glycerol and different kinds of fatty acids. Preferably use is made of vegetable fats and oils, which may be subjected to hardening or not, depending on the envisaged consistency. Suitable vegetable fats include castor oil, soybean oil, almond oil, canola oil, cottonseed oil, peanut oil, sunflower oil, palm oil, palm nut oil, linseed oil, corn oil, olive oil, sesame oil, cocoa butter and coconut fat. Further useful fats include esters of glycerol with triple C12-60 hydrogenated fatty acids. An example is hydrogenated castor oil. Mono- and di-glycerides and mixtures thereof may be included in the composition of this invention as well.
The composition of this invention may further comprise one or more fatty alcohols and/or one or more fatty acids, in particular C12-50 fatty alcohols. C12-24 fatty alcohols are usually extracted from natural fats, oils and waxes. Some examples include myristyl alcohol, 1- pentadecanol, cetyl alcohol, 1-heptadecanol, stearyl alcohol, 1-nonadecanol, arachidyl alcohol, 1-heneicosanol, behenyl alcohol, brassidyl alcohol, alcohol lignoceryl, ceryl alcohol or mycricyl alcohol and Guerbet alcohols. Other suitable fatty alcohols are fractions of fatty alcohol obtained by hydrogenation of naturally occurring fats and oils. Examples include beef tallow, peanut oil, canola oil, cottonseed oil, soybean oil, sunflower oil, palm nut oil, linseed oil, caster oil, corn oil, sesame oil, cocoa butter and coconut oil. Besides the afore mentioned fatty alcohols from natural sources, synthetic fatty alcohols and/or waxes may be used as well, such as fatty alcohols with a wax-like fat component (e.g. Lannette O).
The composition of this invention may further contain one or more waxes to provide a matrix for the other components and to achieve the desired consistency and texture of the composition. The use of a wax is particularly suitable in case the composition takes the form of a stick, which is rubbed over the skin to achieve application of the composition. Suitable waxes include vegetable waxes, for example candelilla wax, carnauba wax, Japan wax, esparto grass wax, ouricury wax, cork wax, guarama wax, rice oil wax, sugarcane wax, Montan wax, sunflower wax and various kinds of fruit waxes (orange wax, lemon wax, grapefruit wax and bayberry wax). Suitable waxes also include animal waxes, for example bee wax, shellac wax, spermaceti, wool wax and uropygial fat; mineral waxes, for example ceresin and ozocerite and petrochemical waxes such as petrolateum, paraffin waxes and micro waxes may also be applied in this invention. Other suitable waxes include chemically modified waxes, including Montan ester waxes, Sasol waxes and hydrogenated jojoba waxes. Fully synthetic waxes may be used as well. Other examples of suitable waxes include C16-40 alkyl stearates, C20-40 alkyl stearates, C20-40 dialkyl esters of dimer acids, C18-38 alkyl hydroxystearoyl stearates or C20-40 alkyl erucaten, C30-50 alkyl beeswax, tristearyl citrate, triisostearyl citrate, stearyl heptanoate, stearyl octanoate, trilauryl citrate, ethylene glycol di(12-hydroxystearate), stearyl stearate, palmityl stearate, stearyl behenaat, cetyl esters, cetearyl behenate and behenyl behenate, myristyl lactate, and silicone waxes. Silicone waxes bind well to the skin and are therefore useful for this invention. The silicone wax, which is preferably used in this invention, is an alkylmethylsiloxane, a non-greasy wax with skin softening properties. The silicone wax has also a further thickening property for oil in water and water in silicone emulsions.
In certain preferred embodiments of the composition of this invention, use may be made of oils. Oils are fats or fat mixtures which are liquid at 20°C and immiscible with water at 25°C. Suitable for use with the composition of this invention are all oil components not covered by the dialkyl(ene) ethers, dialkyl(ene) carbonates, acids or dicarbocyclic hydroxyvetalcohols. Examples of suitable oils include oils of glycerides, hydrocarbons, silicone, liquid ester oil (20°C) and mixtures thereof. Glycerides of oils, both natural and synthetic oils and their derivatives as well as Guerbet alcohols and their derivatives may also be used. Examples of oils suitable for use with this invention include hydrocarbons in squalane, squalene, paraffin oils, isohexadecane, isoeicosane, polydecenes and dialkyl cyclohexanes.
Examples of liquid wax ester oils include esters and their derivatives. Namely decyl oleate (Cetiol®V, coccaprylate / caprate (Cetiol ® SN), hexyl laurate (Cetiol ® A), myristyl myristate (Cetiol ® MM), myristyl isostearate, myristyl oleate, cetyl isostearate, cetyl oleate, stearyl isostearate, stearyl oleate, isostearyl myristate, isostearyl palmitate, isostearyl stearate, isostearyl isostearate, isostearyl oleate, isostearylbehenate, isostearyl oleate, oleyl myristate, oleyl palmitate, oleyl stearate, oleyl isostearate, oleyl oleate (Cetiol ® DAB), oleyl behenate, oleyl erucaat (Cetiol ® J 600), Behenyl isostearate, behenyl oleate, erucyl isostearate, erucyl oleate.
Furthermore, also esters of C6-22 fatty acids with branched/non- branched alcohols, esters of C18-38 alkylhydroxycarbocyclic acids with branched/non-branched C6-22 fatty alcohols, esters of branched / non- branched fatty acids with polyhydric alcohols (e.g. propylene glycol) esters of Guerbet alcohols and esters of C6-22 fatty alcohols, esters of benzoic acid and esters of Guerbetalcohols with C2-12 dicarbocyclic acids with branched / non- branched alcohols (e.g. Dioctyl malate) may be used. Examples of silicone oils include dialkyl and alkylaryl siloxanes (cyclomethicone, dimethyl polysiloxane, methylphenyl polysiloxane and alkoxylated and quaternized analogs thereof). The implementation preferably uses oils from the latter group.
Humectants as well as skin conditioning products may be added as additives to the composition of this invention. The humectant allows for increased awareness properties of the full product upon application, by ensuring a pleasant feeling to arise when applying the composition of this invention to the skin. Furthermore, the humectant allows for better control of the moisture concentration on the skin and an increased level of product penetration at the position of the skin (epidermis). The following humectants are deemed to be suitable: amino acids, pyrrolidone carboxcyclic acids, lactic acids and their salts, lactitol, urea and its derivatives, uric acid, glucosamine, creatinine, collagen particles, chitosan and its derivatives, polyols and polyolderivates. Examples of polyolderivates include glycerol, diglycerol, triglycerol, ethylene glycol, propoyleenglycol, butylene, erythritol, 1 ,2,6- hexanetriol, polyethylene glycols such as PEG-4, PEG-6, PEG-7, PEG-8, PEG-9, PEG- 10, PEG-12, PEG-14, PEG-16, PEG-18, PEG-20. Sugars and derivatives of sugars (fructose, glucose, maltose, malitol, mannitol, inositol, sorbitol, sorbityl silanediol, sucrose, trehalose, xylose, xylitol, glucuronic acid and salts), ethoxylated sorbitol (Sorbeth-6, Sorbeth-20, Sorbeth- 30, Sorbeth- 40), honey and hydrogenated honey, hydrogenated starch hydrolysates of, mixing hydrogenated wheat protein and PEG-20-acetate copolymers.
Preferably, the invention also uses an emulsifier. More specifically a non-ionic emulsifier. Non-ionic emulsifiers are dermatologically very compatible and have furthermore mild ecotoxicological properties. Various emulsifiers are possible. Sorbitan mono-and diesters of saturated and unsaturated fatty acids, alkyl mono and oligoglycosides, polyol and various mixed esters thereof. Partially saturated/unsaturated/branched/non-branched C6-22 fatty acids, ricinoleic acid, 12-hydroxystearic acid and polyglycerol, pentaerythritol, dipentaerythritol, sugar alcohols, alkyl glucosides, polyglycosides or mixed esters (e.g. glyceryl stearate citrate and glyceryl stearate lactate). Mixed esters of pentaerythritol, citric acid, fatty alcohols and/or mixed esters of C6-22 fatty acids, methyl glucose and polyols. Polysiloxane/polyalkyl/polyether copolymers and related derivatives. This invention preferably makes use of the latter group of emulsifiers as they permit to incorporate a large concentration of polysiloxanes into the composition.
In certain preferred embodiments of the invention use may also be made of anionic surfactants. Anionic surfactants contain a lipophilic end and a water-soluble anionic group. Examples of anionic groups are carboxylates, sulphates, sulphonates and phosphates. Anionic surfactants are commercially widely used in dermatological preparations and are therefore easily available. Several types are available, alkyl sulfates in the form of their alkali metal, ammonium and alkanolammonium salts, alkylether, alkyl ether carboxylates, acyl isethionate, acyl sarcosinates, acyl taurine with unbranched C 12-18 alkyl or acyl groups and acyl glutamates in the form of their alkali metal or ammonium salt. The invention uses an anionic surfactant from the group of the carboxylates.
If so desired, the composition of this invention may comprise one or more preservatives. These are natural or synthetic products which may be added to a formulation, so that decomposition by microbial growth or undesirable chemical changes are avoided. Examples of preservatives are phenoxyethanol, formaldehyde solution, parabens, pentanediol or sorbic acid. The invention uses a preservative from the group of the parabens. The preferred amounts are between 0.1-1.0 wt. % of the total weight of the formulation. Parabens are esters of parahydroxybenzoic acid. Common parabens are methyl paraben (E218), ethyl paraben (E214), propylparaben (E216), butylparaben, isobutylparaben, isopropylparaben, benzylparaben and their salts.
The composition of this invention will usually contain an amount of water, as a solvent for the water soluble compounds.
The composition of this invention may be presented in a wide variety of galenic forms, to permit optimal application to scar tissue. Therefore, the present invention also relates to a kit for the treatment of scars which contains the above described topical composition.
The composition of this invention may for example be used in the form of a cream or ointment or gel. Preferably however, the composition of this invention is used in the form of a stick. The composition may be applied to the skin by rubbing the stick over the skin and/or scar tissue. With each contact a layer of the composition will be applied to the skin. The layer thickness may be controlled by repeating the rubbing action and by applying a plurality of subsequent layers on top of each other.
The invention further relates to an applicator device comprising the skin care composition of this invention, suitable for application of the composition to a scar. Preferably, the applicator device contains the topical composition of this invention in the form of a stick which contains the above described topical composition. Thereby, the applicator preferably comprises an open top along which the stick may at least partly protrude. The stick is preferably moveably positioned in the applicator so as to permit advancing the stick towards the open top of the applicator or retracting it therefrom. By ensuring that at least part of the stick protrudes from the interior of the applicator, the stick may be brought into contact with the skin/scar tissue and be applied thereon. The use of an applicator device in the galenic form of a stick containing the skin care product, ensures easy and direct deposition of the topical composition on topically relevant local skin area without additional manual operations being required. This way the risk to cross-contamination due to contact of fingertips is reduced to a minimum. Upon application to the scar tissue, slow melt-down of the composition is ensured due to skin contact, which results in the deposition of layers of virtually constant thickness. The use of a stick permits application of the topical composition and targetting of the active components where needed.
The composition of this invention will usually take the form of a clear, transparent formulation. The transparency is important because it allows constant evaluation of the scar tissue without the need to remove the protective film.
This invention further relates to a method for repairing scars by application of one or more layers of the composition of this invention. Examples.
A composition for repaing scars was prepared by mixing the compounds listed in table 1 below I the amounts indicated. The concentration of each component is given in wt. % with respect to the total weight of the composition. The composition was then moulded into the form of a stick.
Table 1 :
10-20 propylene glycol PH humectant
5-15 Pleurasan glucan Skin care product
0.01-3 PVP/VA S-630 polyvinylpolymer Film forming agent
0.01-3 PVP K30 polyvinylpolymer Film forming agent
Solvent for the
1-5 ethyl alcohol polyvinylpolymer
methyl paraben = nipagin - 03020 Preservative
2-10 eusolex 9020 - 03,264 uv-filter
1-8 Sodium stearate Surfactant
10-20 PPG-3 Myristyl Ether humectant Humectant
2-10 Eusolex T-2000 UV-filter uv-filter
5-15 Emulsifier 10 Emulsifier
1-10 DC AMS-30 Wax
20-60 SF1202 Protective film
4 different compositions A, B, C and D are mixed to prepare the composition of this invention. After mixing, the mixture was moulded into the form of a stick. The composition of the different compositions is given in table 2. The concentration of each component is given in wt. % with respect to the total weight of the composition. Table 2:
Lanette O/Cetostearylalcohol 50 fatty
10-30 acids and fatty alcohols / wax Stick forming agent
1-5 Hydracire S wax Stick forming agent
0.1-1 Methylparaben Preservative
2-10 Eusolex 9020 UV-filter UV-filter
2-10 Eusolex OCR UV-Filter UV-Filter
1 -3 Tocopheryl Acetate, Synthe. Vit. E Additive
1-3 Cosmedia DC additive Additive
1-10 Dow Corning ST-Wax 30 wax Wax
0.01-3 Polyvidon 25 Ph Eur. polyvinylpolymer Film forming agent
1-5 Alcohol 96% + 0,5 DEP alcohol Solvent
5-15 Pleurasan CH Cosmetic Hydrogel Scin care product
0.01-3 Mowiol 18/88 Film forming agent
1-5 Demi water Bulk
20-60 Dow Corning 345 Protective film
5-15 Dow Corning Emulsifier 10 Protective film