POLYAMINO SALTS OF ALPHA-HYDROXYACIDS, ALPHA KETOACIDS AND RELATED COMPOUNDS

BACKGROUND OF THE INVE.NTION

Field of the Invention

The invention concerns cosmetic compositions and methods using such compositions for topical application to human skin. More particularly, the invention concerns an improved system for the delivery of α-hydroxy compounds that overcomes formulation difficulties and improves sensory properties.

The Related Art

A soft, supple and flexible skin has a marked cosmetic appeal and is an attribute of normal functioning epidermis.

As human skin ages with advancing years, the epidermis can become folded or ridged or furrowed to form wrinkles which signal the loss of youthful appearance and herald the transition to old age. This transition can even occur prematurely with young people, especially those who expose themselves to excessive doses of sunlight. Also, the outer layer of the epidermis, that is the stratum corneum, can become dry and flaky following exposure to cold weather, or excessive contact with detergents or solvents which result in loss of skin moisture. Thereby, skin loses its soft, supple and flexible characteristics.

Emollients such as fats, phospholipids and sterols have in the past been used to soften wrinkled or dry skin, but it is apparent that these emollients are only partially effective as a remedy for skin in poor condition.

The use of o.-hydroxyacids for enhancing the quality of human skin following topical application thereto has been widely reported.

U.S. Patent 4,105,782 and U.S. Patent No. 4,105,783, both to Yu and Van Scott, disclose the use of amines or ammonium salts of c--hydroxyacids in the treatment of acne, dandruff and dry skin. U.S. Patent 4,234,599 (Yu & Van Scott) proposes the use of α-hydroxyacids and their esters or amine salts in the treatment of keratoses. U.S. Patent 4,363,815 (Yu & Van Scott) suggests the use of α.- hydroxyacids or -hydroxyacids or ketoacids and their derivatives, in a composition for treating skin conditions. Most recently, U.S. Patent 5,091,171 (Yu & Van Scott) reports the use of cx-hydroxyacids, α-ketoacids and related compounds as topically effective in the treatment of warts, nail infections, age spots, wrinkles and aging related skin changes.

U.S. Patent 4,424,234 (Alderson et al. ) identifies C ₆ -C ₁₀ a- hydroxy carboxylic acids as agents for improving human skin, particularly with emphasis upon the conditions of dryness and flakiness. U.S. Patent 4,612,331 (Barratt et al.) reports that α-hydroxyoctanoic acid when combined with a neutralising agent such as an alkanolamine enhances the extensibility of the stratum corneum without the development of skin irritation normally occurring in the absence of the neutralising 'agent.

Based on the foregoing disclosures, it is evident that α- hydroxyacids and α-ketoacids have been well established in the art as therapeutically effective for cosmetic and dermatologic conditions and disorders. Unfortunately, formulation chemists have had a difficult time in providing stable creams or lotions containing these compounds in their active forms. Moreover, it is also difficult to deliver these compounds to the skin in their active form

without causing skin irritation.

Accordingly, it is an object of the present invention to provide a cosmetic composition stably incorporating an active form of α-hydroxyacids, α.-ketoacids or related compounds in a cream or lotion.

It is another object of the present invention to provide a cosmetic composition containing α.-hydroxyacids, c--ketoacids or related compounds which when applied to skin in relatively high concentrations will cause less skin irritation than previously achievable.

A still further object of the present invention is to provide a method for treating dry skin, warts, nail infections, age spots, wrinkles and aging related skin changes with compositions that are effective but impart less skin irritation than compositions utilised hitherto.

These and other objects of the present invention that will become more readily apparent from consideration of the following summary, detailed description and examples which follow.

SUMMARY OF THE INVENTION

A cosmetic composition is provided comprising:

i) an active compound comprising one or more a- hydroxyacids of formula (I)

OH wherein R ¹ and R ² represent H, F, CI, Br, alkyl,

aralkyl and aryl radicals whether saturated or unsaturated, isomeric or nonisomeric, straight or branched chain, having 1 to 25 carbon atoms, or in cyclic form having 5 to 6 ring members, and in addition R ¹ and R ² may be substituted by OH, CHO, COOH and alkoxy groups having 1 to 9 carbon atoms, the a- hydroxyacid existing as a free acid or lactone form, or in salt form with an organic base or an inorganic alkali, and as stereoisomers in D, L, and DL forms when R ¹ and R ² are not identical;

one or more c--ketoacids of formula (II)

_(II) R ¹ -C—COOR ²

O

wherein R ¹ and R ² represent H, alkyl, aralkyl and aryl radicals whether saturated or unsaturated, isomeric or nonisomeric, straight or branched chain, having 1 to 25 carbon atoms, or in cyclic form having 5 to 6 ring members, and in addition R ¹ may be substituted by F, CI, Br, I, OH, CHO, COOH and alkoxy groups having 1 to 9 carbon atoms, the α-ketoacid existing as a free acid or an ester form, or in a salt form with an organic base or an inorganic alkali; or

one or more related compounds comprising ascorbic acid, quinic acid, isocitric acid, tropic acid, trethocanic acid, 3-chlorolactic acid, cerebronic acid, citramalic acid, agaricic acid, 2- hydroxynervonic acid, aleuritic acid and pantoic acid;

a multi-amine functionalised polymer, the polymer neutralising at least some of the active compound thereby forming an amine salt thereof; and

radicals and may either be saturated or unsaturated, isomeric or nonisomeric, straight or branched chain, having 1 to 25 carbon atoms, or cyclic in form having 5 to 6 ring members, and in addition R ¹ and R ² may be substituted by OH, CHO, COOH and alkoxy groups having 1 to 9 carbon atoms, the c--hydroxyacid existing as a free acid or lactone form, or in salt form with an organic base or an inorganic alkali, and as stereoisomers in D, L and DL forms when R ¹ and R ² are not identical. The L form is most preferred.

Typical alkyl, aralkyl and aryl groups for R ¹ and R ² include methyl, ethyl, propyl, isopropyl, butyl, pentyl, octyl, lauryl, stearyl, benzyl and phenyl.

The α;-hydroxyacids, as noted above, can be classified as

(1) alkyl α;-hydroxyacids, (3) aralkyl and aryl - hydroxyacids, (3) polyhydroxy alpha hydroxyacids, and (4) polycarboxylic c--hydroxyacids. The following are representative c--hydroxyacidε in each subgroup.

.1) Alkyl Q?-Hydroxyacids

1. 2-Hydroxyethanoic acid (Glycolic acid, hydroxyacetic acid) (H) (H) C (OH) COOH

2. 2-Hydroxypropanoic acid (Lactic acid) (CH ₃ ) (H) C (OH) COOH

3. 2-Methyl 2-hydroxypropanoic acid (Methyllactic acid) (CH ₃ ) (CH ₃ ) C (OH) COOH

4. 2-Hydroxybutanoic acid (C ₂ H ₅ ) (H) C (OH) COOH

5. 2-Hydroxypentanoic acid (C ₃ H ₇ ) (H) C (OH) COOH

iii) a pharmaceutically acceptable carrier for the amine salt.

Also provided is a method for treatment of dry skin, warts, nail infections, age spots, wrinkles and aging related skin changes that includes topically applying to skin the cosmetic compositions defined above, and which method will minimise skin irritation.

DETAILED DESCRIPTION

The present inventors have found that α.-hydroxyacids, a>- ketoacids and related compounds can be more readily formulated and their skin irritation minimised when they are neutralised at least partially with a multi-amine functionalised polymer.

Thus, the first important element of the claimed invention is an active compound which is either an α-hydroxyacid, a α.-ketoacid or a related compound. The active compound may conveniently be present in an amount from 0.01 to 40%, preferably from 0.1% to 20%, optimally between 0.5 and 12% by weight of the composition.

The Q.-hydroxyacid may conveniently be selected from the group consisting of alkyl α.-hydroxyacid, aralkyl and aryl α-hydroxyacid, polyhydroxy α-hydroxyacid and polycarboxylic Oa-hydroxyacid represented -by the following chemical structure:

R ^{2 (I)} R ¹ C—COOH

OH

wherein R ¹ and R ² are H, F, CI, Br, alkyl, aralkyl or aryl

6. 2-Hydroxyhexanoic acid (C ₄ H ₉ ) (H) C (OH) COOH

7. 2-Hydroxyheptanoic acid (C ₅ H _U ) (H) C (OH) COOH

8. 2-Hydroxyoctanoic acid (C ₆ H ₁₃ ) (H) C (OH) COOH

9. 2-Hydroxynonanoic acid (C ₇ H ₁₅ ) (H) C (OH) COOH

10. 2-Hydroxydecanoic acid (C _g H ₁₇ ) (H) C (OH) COOH

11. 2-Hydroxyundecanoic acid (C ₉ H ₁₉ ) (H) C (OH) COOH

12. 2-Hydroxydodecanoic acid (Alpha hydroxylauric acid) (C ₁₀ H ₂₁ ) (H) C (OH) COOH

13. 2-Hydroxytetradecanoic acid (Alpha hydroxymyristic acid)

(C ₁₂ H ₂₅ ) (H) C (OH) COOH

14. 2-Hydroxyhexadecanoic acid (Alpha hydroxypalmiπic acid)

(C ₁₄ H ₂₉ ) (H) C (OH) COOH

15. 2-Hydroxyoctadecanoic acid (Alpha hydroxystearic acid) (C ₁₆ H ₃₄ ) (H) C (OH) COOH

16. 2-Hydroxyeicosanoic acid (Alpha hydroxyarachidonic acid) ( ι ₈ H ₃₇ ) (H) C (OH) COOH

(2) Aralkyl And Aryl Alpha Hydroxyacids

1. 2-Phenyl 2-hydroxyethanoic acid (Mandelic acid) (C ₆ H ₅ ) (H) C (OH) COOH

2. 2,2-Diphenyl 2-hydroxyethanoic acid (Benzilic acid) (C ₆ H ₅ ) (C ₆ H ₅ ) C (OH) COOH

3. 3-Phenyl 2-hydroxypropanoic acid (Phenyllactic acid) (C ₆ H ₅ CH ₂ ) (H) C (OH) COOH

4. 2-Phenyl 2-methyl 2-hydroxyethanoic acid (Atrolactic acid)

(C ₆ H ₅ ) (CH ₃ ) C (OH) COOH

5. 2- (4 ' -Hydroxyphenyl) 2-hydroxyethanoic acid (4- Hydroxymandelic acid)

(HO-C ₆ H ₄ ) (H) C (OH) COOH

6. 2- (4' -Chlorophenyl) 2-hydroxyethanoic acid (4- Chloromandelic acid) (C1-C ₆ H ₄ ) (H) C (OH) COOH

7. 2- (3 ' -Hydroxy-4 ^■ -methoxyphenyl) 2-hydroxyethanoic acid (3-Hydroxy-4-methoxymandelic acid)

(HO-,CH ₃ 0-C ₆ H ₃ ) (H) C (OH) COOH

8. 2- (4 ' -Hydroxy-3 ' -ethoxyphenyl) 2-hydroxyethanoic acid (4-Hydroxy-3-methoxymandelic acid) (HO-,CH ₃ 0-C ₆ H ₃ ) (H) C (OH) COOH

9. 3- (2 ' -Hydroxyphenyl) 2-hydroxypropanoic acid [3- (2 'Hydroxyphenyl) lactic acid] HO-C ₆ H ₄ -CH ₂ (H) C (OH) COOH

10. 3- (4' -Hydroxyphenyl) 2-hydroxypropanoic acid [3- (4 'Hydroxyphenyl) lactic acid]

HO-C ₆ H ₄ -CH ₂ (H) C (OH) COOH

11. 2- (3' ,4' -Dihydroxphenyl) 2-hydroxyethanoic acid (3,4'Dihydroxymandelic acid) HO-,HO-C ₆ H ₃ (H) C (OH) COOH

(3) Polyhydroxy Alpha Hydroxyacids

1. 2,3-Dihydroxypropanoic acid (Glyceric acid) (HOCH ₂ ) (H) C (OH) COOH

2. 2,3,4-Trihydroxybutanoic acid, (Isomers: erythronic acid and threonic acid)

HOCH ₂ (HO)CH ₂ (H) C (OH) COOH

3. 2,3,4,5-Tetrahydroxypentanoic acid (Isomers: ribonic acid., arabinoic acid, xylonic acid and lyxonic acid) HOCH ₂ (HO)CH ₂ (HO)CH ₂ (H) C (OH) COOH

4. 2,3,4,5,6-Pentahydroxyhexanoic acid (Isomers: allonic acid, altronic acid, gluconic acid, mannoic acid,gulonic acid, idonic acid, galactonic acid and talonic acid) HOCH ₂ (HO)CH ₂ (HO)CH ₂ (HO)CH ₂ (H) C (OH) COOH

5. 2,3,4,5, 6, 7-Hexahydroxyheptanoic acid (Isomers: glucoheptonic acid, galactoheptonic acid, etc.) HOCH ₂ (HO)CH ₂ (HO)CH ₂ (HO)CH ₂ (HO)CH ₂ (H) C (OH) COOH

(4) Polycarboxylic Alpha Hydroxyacids

1. 2-Hydroxypropane-l, 3-dioic acid (Tartronic acid) HOOC (H) C (OH) COOH

2. 2-Hydroxybutane-l,4-dioic acid (Malic acid) HOOC CH, (H) C (OH) COOH

3. 2,3-Dihydroxybutane-l,4-dioic acid (Tartaric acid) HOOC (HO)CH (H) C (OH) COOH

4. 2-Hydroxy-2-carboxypentane-l,5-dioic acid (Citric acid)

HOOC CH ₂ C (OH) (COOH) CH ₂ COOH

5. 2,3,4,5-Tetrahydroxyhexane-l, 6-dioic acid (Isomers; saccharic; acid, mucic acid, etc.) HOOC (CHOH) ₄ COOH

(5) Lactone Forms

The typical lactone forms are gluconolactone, galactonolactone, glucuronolactone, galacturonolactone, gulonolactone, ribonolactone, saccharic acid lactone, pantoyllactone, glucoheptonolactone, mannonolactone, and galactoheptonolactone.

The second type of active compound according to the present invention is an organic carboxylic acid in which the alpha carbon is in keto form. The generic structure of such α.- ketoacids may be represented as follows:

(II) (R ¹ ) CO COO(R ² )

wherein R ¹ and R ² are H, alkyl, aralkyl or aryl groups that are saturated or unsaturated, isomeric or non-isomeric, straight or branched chain or in cyclic form, having 1 to 25 carbon atoms, and in addition R ¹ may be substituted by F, CI, Br, I, OH, CHO, COOH and alkoxy group having 1 to 9 carbon atoms. The α-ketoacids may be present as a free acid or an ester form, or in a salt form with an organic base or an inorganic alkali. The typical alkyl, aralkyl and aryl groups for R ¹ and R ² include methyl, ethyl, propyl, isopropyl, butyl, pentyl, octyl, lauryl, stearyl, benzyl and phenyl.

In contrast to a-hydroxyacids the ester form of c--ketoacids is known to be therapeutically effective for cosmetic and dermatologic conditions and disorders. For example, while ethyl acetate is reported to have a minimal effect, ethyl pyruvate is therapeutically very effective. Although the real mechanism for such difference is not known, it has been speculated that the ester form of an α-ketoacid is chemically and/or biochemically very reactive, and a free acid form of the α.-ketoacid is released in the skin after the topical application.

The representative c--ketoacids and their esters which may be useful in compositions of this invention include:

1. 2-Ketoethanoic acid (Glyoxylic acid) (H) CO COOH

2. Methyl 2-ketoethanoate

(H) CO COOCH ₃

3. 2-Ketopropanoic acid (Pyruvic acid) CH ₃ CO COOH

4. Methyl 2-ketopropanoate (Methyl pyruvate) CH ₃ CO COOCH ₃

5. Ethyl 2-ketopropanoate (Ethyl pyruvate) CH ₃ CO COOC ₂ H ₅

6. Propyl 2-ketopropanoate (Propyl pyruvate)

CH ₃ CO COOC ₃ H ₇

7. 2-Phenyl-2-ketoethanoic acid (Benzoyl formic acid) C ₆ H ₅ CO COOH

8. Methyl 2 -phenyl - 2 - ke t oe thanoat e (Methyl benzoyl formate)

C ₆ H ₅ CO COOCH ₃

9. Ethyl 2-phenyl-2-ketoethanoate (Ethyl benzoylf ormate) C ₆ H ₅ CO COOC ₂ H ₅

10. 3-Phenyl-2-ketopropanoic acid (Phenylpyruvic acid) C ₆ H ₅ CH ₂ CO COOH

11. Methyl 3 -phenyl - 2 - ke t opropanoat e (Methyl phenylpyruvate)

C ₆ H ₅ CH ₂ CO COOCH ₃

12. Ethyl 3-phenyl-2-ketopropanoate (Ethyl phenylpyruvate) C ₆ H ₅ CH ₂ CO COOC ₂ H ₅

13. 2-Ketobutanoic acid C ₂ H ₅ CO COOH

14. 2-Ketopentanoic acid C ₃ H ₇ CO COOH

15. 2-Ketohexanoic acid C ₄ H ₉ CO COOH

16. 2-Ketoheptanoic acid

C ₅ H _n CO COOH

17. 2-Ketooctanoic acid C ₆ H ₁₃ CO COOH

18. 2-Ketododecanoic acid Cι ₀ H ₂ ιCO COOH

19. Methyl 2-ketooctanoate C ₆ H ₁₃ CO COOCH ₃

The third type of active compound according to the present

invention is chemically related to α-hydroxyacids or α.- ketoacids, and can be represented by their names instead of the above two generic structures. The third type of active compound includes ascorbic acid, quinic acid, isocitric acid, tropic acid, trethocanic acid, 3-chlorolactic acid, cerebronic acid, citramalic acid, agaricic acid, 2- hydroxynervonic acid, aleuritic acid and pantoic acid.

Amino Polymer

A second essential element of the cosmetic compositions according to the present invention is that of a multi-amine functionalised polymer. The polymer must be capable of effectively neutralising at least some of the active compounds thereby forming an amine salt thereof. Ordinarily the polymer will have a pH in water from 7.5 to 14. Amounts of the polymer will generally range from 0.01 to 40%, preferably from 0.1 to 20%, optimally between 0.5 and 10% by weight of the composition. Advantageously, the molar equivalent weight ratio of active compound to polymer will be from 50:1 to 1:10, preferably 20:1 to 1:5, more preferably from 5:1 to 1:2, optimally from 2:1 to 1:1. The polymer may have a structure commensurate with Formula

(III) or (IV) below:

(HI] I ⁿ

R3

wherein:

R ⁴ , R ⁵ and R ⁶ are independently Cι-C ₁₂ radicals substituted or unsubstituted, branched or unbranched chains selected from the group consisting of alkylene, arylene, arylalkylene, alkylarylene and cycloalkylene radicals;

R ³ , R ⁷ and R ⁸ are independently hydrogen or -C^ radicals selected from the group consisting of alkyl, cycloalkyl, aryl, phenyl, benzyl and hydroxyalkyl radicals,-

R ⁷ and R ⁸ may also form with nitrogen a heterocyclic rign such as a pyridine, pyrrolidone, piperidine and piperazine ring,-

X is OR ³ or N(R ⁷ ) (R ⁸ ) ;

n and m together are integers of at least 2, preferably from 5 to 5000; and

n and m separately are integers from 0 to 5000, preferably from 2 to 1000, optimally from 5 to 100.

Molecular weight of the polymers may range anywhere from

500 up to 4 million, preferably from 1,000 to 2 million, optimally from 10,000 to 800,000 average molecular weight.

These polymers may conveniently be obtained through condensation or free radical vinyl polimerisation techniques. They may be homo- or co- polymers.

Illustrative of the polymers according to the present invention as defined in Formula I are:

poly(ethylenimine) poly(propylenimine) poly(aminophenylene) poly(butylenimine) diethylenetriamine triethylenetetramine

Illustrative of the polymers according to Formula II are:

poly(phenylamine) poly(p-aminostyrene) poly(o-aminostyrene) poly(m-aminostyrene) poly(p-dimethylaminostyrene) poly(p-ditert-butylaminostyrene) poly(vinylamine) poly(vinylpyridine) poly(diethylamino ethyl acrylate) poly(diethylamino ethylacrylamide) poly(dimethylamino ethylacrylate) poly(dimethylamino ethylacrylamide) poly(diethylamino ethyl methacrylate) poly(diethylamino ethyl methacrylamide) poly(vinylpyrrolidone/dimethylamino ethyl methacrylate)

Polymers of the present invention as herein defined are neither aminoacids nor amphoteric or polysaccharide substances.

Cosmetic compositions of the present invention will also include a pharmaceutically acceptable carrier, conveniently in amounts from 1 to 95% by weight of the composition. The carrier may be an emollient, humectant, thickener and any combination thereof.

Emollient materials may either be silicone oils or organic esters .

Silicone oils may be divided into the volatile and non-volatile variety. The term "volatile" as used herein refers to those materials which have a measurable vapor pressure at ambient temperature. Volatile silicone oils are preferably chosen from cyclic or linear polydimethylsiloxanes containing from 3 to 9, preferably from 4 to 5, silicon atoms.

Linear volatile silicone materials generally have viscosities less than 5 centistokes at 25°C while cyclic materials typically have viscosities of less than 10 centistokes.

Nonvolatile silicone oils useful as an emollient material include polyalkyl siloxanes, polyalkylaryl siloxanes and polyether siloxane copolymers . The essentially non-volatile polyalkyl siloxanes useful herein include, for example, polydimethyl siloxanes with viscosities of from 5 to 100,000 centistokes at 25°C. Among the preferred non-volatile emollients useful in the present compositions are the polydimethyl siloxanes having viscosities from 10 to 400 centistokes at 25°C.

Among the ester emollients are:

(1) Alkenyl esters of fatty acids having 10 to 20 ^' carbon atoms. Examples thereof include oleyl myristate, oleyl stearate, and oleyl oleate.

(2) Ether-esters such as fatty acid esters of ethoxylated fatty alcohols.

(3) Polyhydric alcohol esters. Ethylene glycol mono and di-fatty acid esters, diethylene glycol mono- and

di-fatty acid esters, polyethylene glycol (200-6000) mono- and di-fatty acid esters, propylene glycol mono- and di-fatty acid esters, polypropylene glycol 2000 monooleate, polypropylene glycol 2000 monostearate, ethoxylated propylene glycol monostearate, glyceryl mono- and di-fatty acid esters, polyglycerol poly-fatty esters, ethoxylated glyceryl monostearate, 1,3-butylene glycol monostearate, 1,3-butylene glycol distearate, polyoxyethylene polyol fatty acid ester, sorbitan fatty acid esters, and polyoxyethylene sorbitan fatty acid esters are satisfactory polyhydric alcohol esters.

(4) Wax esters such as beeswax, spermaceti, myristyl myristate, stearyl stearate.

(5) Sterols esters, of which cholesterol fatty acid esters are examples thereof.

Humectants of the polyhydric alcohol-type may also be included in the compositions of this invention. The humectant aids in increasing the effectiveness of the emollient, reduces scaling, stimulates removal of built-up scale and improves skin feel . Most especially for purposes of this invention, polyhydric alcohols enhance penetration of water-phase dissolved actives (e.g. the hydroxycarboxylic acids, alkyl lactates and antimicrobials) . Typical polyhydric alcohols include glycerol, polyalkylene glycolε and more preferably alkylene polyols and their derivatives, including propylene glycol, dipropylene glycol, polypropylene glycol, polyethylene glycol and derivatives thereof, sorbitol, hydroxypropyl sorbitol, hexylene glycol, 1,3-butylene glycol, 1, 2, 6-hexanetriol, ethoxylated glycerol, propoxylated glycerol and mixtures thereof. For best results the humectant is preferably propylene glycol . The amount of humectant may range anywhere from 0.5 to 30%, preferably

between 1 and 15% by weight of the composition.

Of course, water is the most common humectant. Water may generally be present in amounts anywhere from 1 to 99%, preferably from 25 to 75% by weight _y

Thickeners/viscosifiers in amounts up to 5% by weight of the composition may suitably also be included. As known to those skilled in the art, the precise amount of thickeners can vary depending upon the consistency and thickness of the composition which is desired. Exemplary thickeners are xanthan gum, sodium carboxymethyl cellulose, hydroxyalkyl and alkyl celluloses (particularly hydroxypropyl cellulose) , and cross-linked acrylic acid polymers such as those sold by B.F. Goodrich under the Carbopol trademark.

Solvents may also be included in cosmetic compositions of the present invention. Most commonly, the solvent is a C _j - C ₄ monohydric alcohol especially ethanol. The monohydric alcohols may conveniently be present in amounts of from 1 to 99%, preferably from 15 to 70% by weight.

Cosmetic compositions of the present invention may be formulated in a variety of product forms. These forms may include lotions, creams, sticks, roll-on formulations, mousses, aerosol sprays, pad-applied formulations, and overnight peelable facial masks.

In order that the invention may be well understood, the following examples are given by way of illustration only. All parts, percentages and proportions referred to herein and in the appended claims are by weight unless otherwise indicated.

EXAMPLE 1

This Example illustrates a facial cleansing foam formulated in accordance with the present invention.

FACIAL CLEANSING FOAM

COMPONENT WEIGHT %

Sodium Cocoyl Isethionate 18.0

L-Lactic Acid Neutralised with Poly(ethylenimine) 5.5

Sodium Lauroyl Sarcosinate 3.0

Glycol Stearate 3.0

PPG-5-Ceteth-10-Phosphate 2.5

Cetearyl Alcohol 1.0

Sorbitol 1.0

Linoleamide DEA 1.0

Mineral Oil 0.8

Beeswax 0.7

Ceresin 0.4

Sodium Borate 0.3

Methyl Paraben 0.2 .

Propyl Paraben 0.2

Water qs

EXAMPLE 2

This Example illustrates a skin care lotion formulated in accordance with the present invention.

SKIN CARE LOTION

COMPONENT WEIGHT %

Glycerin 15.0

2-Hydroxyoctanoic Acid neutralised with Poly(ethylenimine) 12.0

Stearic Acid 10.0

C _π -C ₁₃ Isoparaffin 10.0

Glycol Stearate 2.5

Mineral Oil 2.0

Triethanolamine 1.0

Cetyl Alcohol 1.0

Dimethicone 0.8

DEA-Cetyl Phosphate 0.3

Magnesium Aluminum Silicate 0.4

Acetylated Lanolin Alcohol 0.4

Stearamide AMP 0.3

Methyl Paraben 0.2

Propyl Paraben 0.2

Fragrance 0.2

Carbopol 934 ^® 0.1

Disodium EDTA 0.1

Water qs

EXAMPLE 3

This Example illustrates a deodorant stick formulated in accordance with the present invention.

_*

DEODORANT STICK

COMPONENT WEIGHT %

Propylene Glycol 61.5

Sodium Stearate 5.4

Ethylene Oxide/Propylene Oxide Copolymer 4.8

Glycolic Acid Neutralised with Poly(propylenimine) 3.0

Trichlosan 0.3

Colorant 0.2

Fragrance 1.0

Water qs

EXAMPLE 4

This Example illustrates a self-tanning lotion formulated in accordance with the present invention.

SELF-TANNING LOTION

COMPONENT WEIGHT %

Propylene Glycol 25.0

Dihydroxyacetone 3.0

Polyacrylamide 2.5

Silicone Copolyol 2.0

Lactic Acid Neutralised with Poly(phenylenimine) 1.5

Methylparaben 0.2

Propylparaben 0.2

Fragrance 0.2

Water qs

EXAMPLE 5

This Example illustrates a body rub gel formulated in accordance with the present invention.

BODY RUB GEL

COMPONENT WEIGHT %

Disodium Dimethicone Copolyol Sulfosuccinate 10.0

Jojoba beads 4.0

Cocoamidopropyl betaine 3.0

2-Hydroxyoctanoic Acid Neutralised with Poly(ethylenimine) 3.0

Polysorbate 20 3.0

Carbopol 934 ^® 1.5

Benzyl Alcohol 0.5

Fragrance 0.2

DMDM Hydantoin 0.2

Sea Salt 0.1

Water qs

EXAMPLE 6

This Example illustrates a lipstick formulated in accordance with the present invention.

LIPSTICK

COMPONENT WEIGHT %

Castor Oil 19.5

Isopropyl Palmitate 11.6

Caprylic/Caproic Triglyceride 10.0

Lanolin 7.0

Red 21 Aluminum Lake 7.0

Candelilla Wax 6.6

Propylene Glycol Myristyl Ether Acetate 6.0

Glycerol 5.0

Water 5.0

Titanium Dioxide 4.7

Monoglyceride 3.5

Lanolin Oil 2.5

Ozokerite Wax 2.5

Ascorbic Acid Neutralised with Poly(p-aminostyrene) 2.0

Lecithin 1.0

Polybutene 0.8

Beeswax qs

EXAMPLE 7

This Example illustrates a sunscreen formulated m accordance with the present invention.

SUNSCREEN

COMPONENT WEIGHT %

Acetulan ^® (cetyl acetate and acetylated lanolin alcohol) 8.0

Glycerine 4.0

2-Hydroxylauric Acid Neutralised with Poly(butylenimine) 3.5

Stearic Acid 2.0

Dimethicone 1.0

Magnesium Aluminum Silicate 1.0

Octyl Methoxycinnamate 1.0

Oxybenzone 1.0

Cetyl Alcohol 0.50

Phenoxyethanol 0.3

Water qs

EXAMPLE 8

This Example illustrates an acne lotion formulated in accordance with the present invention.

ACNE LOTION

COMPONENT WEIGHT %

Benzoyl Peroxide 7.0

Glycerin 3.0

Glyceryl Monostearate 3.0

Smectite Clay 2.5

Glycolic Acid Neutralised with Poly(ethylenimine) 2.0

Stearyl alcohol 1.0

Isocetyl stearate 1.0

Preservative 0.4

Water qs

EXAMPLE 9

This Example illustrates an anti-dandruff shampoo formulated in accordance with the present invention.

■ANTI -DaANDRUFF SHAMPOO

COMPONENT WEIGHT %

TEA Lauryl Sulfate (40% Aqueous Solution) 25.0

Hamposyl L-30 (fatty acid sarcosinate) 10.0

Glycolic Acid Neutralised with Poly (o-aminostyrene) 8.0

Zinc Pyrithione 2.2

Hydroxypropyl methylcellulose 1.3

Modified Magnesium Aluminum Silicate 1.0

Water qs

EXTuPLE 10

This Example illustrates a hair growth stimulant formulated in accordance with the present invention.

HAIR GROWTH STIMULANT

COMPONENT WEIGHT %

Sodium Lauryl Ether Sulfate 28.0

Lactic Acid Neutralised with Poly (ethylenimine) 12.0

Lanolin Alcohol 1.0

Polysorbate 20 0.5

Minoxidil ^® , 0.3

Preservative 0.3

Water qs

EX.AMPLE 11

COMPARATIVE TESTS

This Example illustrates comparative tests formulated in accordance with the present invention.

Glycolic acid was chosen as representative of a- hydroxyacids and neutralised to form three different types of salts. The sodium (IIA) and the triethanolammonium (IIB) salts represent the known art. Polyethylenimine (11C) salts of glycolic acid are according to the present invention. The respective test formulas are outlined in Table I below.

TABLE I

COMPONENT TEST FORMULA (WT. %) 11A 11B 11C

Glycolic Acid 11.4 11.4 11.4

Sodium Hydroxide* 6.0 -- --

Triethanolamine (TEA) * -- 22.3 --

Poly(ethylenimine) * -- -- 7.5

Water 82.6 66.3 81.1

Present in an amount just sufficient to neutralise all of the glycolic acid.

A panel of seven subjects was chosen for evaluating the sting intensity of the different glycolate salts. Each of the panelists were prescreened to identify people especially sensitive to the sting aspects of a- hydroxyacids. Each formulation was applied around the nose

and cheek of each panelist. Intensity of stinging was judged on a scale of 0 to 5 (shown as + in the performance table below) . The higher the value, the greater the stinging intensity. Response was judged both at 1 and at 5 minutes subsequent to application of the formulation.

TABLE II

STING INTENSITY

TEST FORMULA (INTENSITY RATING)

PANELIST 11A 11B 11C

1 Min 5 Min 1 Min 5 Min 1 Min 5 Min

1 +++ +++ +++ +++ + 0

2 + + + + 0 0

3 + + + ++ 0 0

4 +++ ++ ++ +++ + +

5 ++ ++++ ++ ++ 0 0

6 + ++ 0 0 0 0

7 + + 0 0

The test results in Performance Table I establish that the polyethylenimine salt was significantly less stinging than either the sodium or triethanolammonium salts of glycolic acid.

The foregoing description and Examples illustrate selected embodiments of the present invention. In light thereof, various modifications will be suggested to one skilled in the art, all of which are within the spirit and purview of this invention.