Use of cosmetic compositions comprising 2-hydrocarboxylic acids and related compounds for alleviating signs of nail changes

Abstract: Uses of topical compositions comprising a 2-hydroxycarboxylic acid or related compound to alleviate or improve signs of skin, nail and hair changes associated with intrinsic or extrinsic aging are disclosed. 2-Hydroxycarboxylic acids and their related compounds include, for example, 2-hydroxyethanoic acid, 2-hydroxypropanoic acid, 2-methyl 2-hydroxypropanoic acid, 2-phenyl 2-hydroxyethanoic acid, 2-phenyl 2-methyl 2-hydroxyethanoic acid, 2-phenyl 3-hydroxypropanoic acid, 2,2-diphenyl 2-hydroxyethanoic acid, 2-hydroxybutane-1,4-dioic acid, 2,3-hihydroxybutane-1,4-dioic acid, 2-carboxy 2-hydroxypentane-1,5-dioic acid, 2-ketopropanoic acid, methyl 2-ketopropanoate, ethyl 2-ketopropanoate, and gluconolactone. Topical application of compositions comprising 2-hydroxycarboxylic acid and/or related compounds has been found to alleviate or improve skin lines; blotches; blemishes; nodules; wrinkles; pigmented spots; atrophy; precancerous lesions; elastotic changes characterized by leathery, coarse, rough, dry and yellowish skin; and other skin changes associated with intrinsic aging or skin damages caused by extrinsic factors such as sunlight, radiations, air pollution, wind, cold, dampness, heat, chemicals, smoke and cigarette smoking. Topical applications of such compositions have also been found to improve the overall qualities of nail and hair affected by intrinsic aging or damaged by extrinsic factors.

Description: FIELD OF THE INVENTION This application relates to topical compositions containing a 2-hydroxycarboxylic acid or a related compound for use in alleviating or improving the dermatological signs of nail associated with intrinsic aging, as well as changes or damage caused by extrinsic factors such as sunlight, radiations, air pollution, wind, cold, heat, dampness, chemicals, smoke, and cigarette smoking. BRIEF DESCRIPTION OF THE PRIOR ART In our U.S.Patent No. 3,879,537 entitled "Treatment of Ichthyosiform Dermatoses" we described and claimed the use of topical compositions containing an alpha hydroxyacid to alleviate the symptoms of ichthyosis. In our U.S.Patent No. 3,920,835 entitled "Treatment of Disturbed Keratinization" we described and claimed the use of topical compositions containing an alpha hydroxyacid to alleviate the symptoms of acne. In our U.S.Patent No. 3,984,566 entitled "Method of Alleviating the Symptoms of Dandruff" we described and claimed the use of topical compositions containing an alpha hydroxyacid to improve the symptoms of dandruff. In our U.S.Patent No. 4,105,783 entitled "Therapeutic Treatment of Dry Skin"; U.S.Patent No. 4,197,316 entitled "Treatment of Dry Skin"; and U.S.Patent No. 4,380,549 entitled "Topical Treatment of Dry Skin"; we described and claimed the use of topical compositions containing an alpha hydroxyacid to alleviate or improve the symptoms of dry skin. In our U.S.Patent No. 4,234,599 entitled "Treatment of Skin Keratoses with Alpha Hydroxyacids and Related Compounds", we described and claimed the use of topical compositions containing an alpha hydroxyacid or the related compound to alleviate the symptoms of actinic or nonactinic skin keratoses. In our U.S.Patent No. 4,363,815 entitled "Alpha Hydroxyacids, Alpha Ketoacids and Their Use in Treating Skin Conditions", we described and claimed the use of topical compositions containing certain alpha hydroxyacids or the related compounds to improve skin conditions characterized by inflammation or disturbed keratinization. In a report entitled "Topical Tretinoin for Photoaged Skin" by Albert M. Kligman, Gary L. Grove, Ryoji Hirose and James J. Leyden published in J. American Academy of Dermatology Vol.15, pages 836-859, 886-887, 1986, daily topical application of 0.05% tretinoin (also known as all-trans retinoic acid) in a cream has been found to improve photodamaged skin. In another report entitled "Topical Tretinoin Improves Photoaged Skin: A Double-blind Vehicle-controlled Study" by Jonathan S. Weiss, Charles N. Ellis, John T. Headington, Theresa Tincoff, Ted A. Hamilton and John J. Voorhees published in J American Medical Association Vol. 259 pages 527-532, 1988, daily topical application of 0.1% tretinoin as compared to vehicle alone application for 16 weeks has been shown to improve photoaged skin. One side-effect has been a dermatitis encountered by 92% of the patients participating in this study. The dermatitis was characterized by a patchy erythema, localized swelling, dry skin, and mild scaling. Patients complained about burning, tingling, or pruritus. In yet another report entitled "Topical Tretinoin in the Treatment of Aging Skin" by Jonathan S. Weiss, Charles N. Ellis, John T. Headington and John J. Voorhees published in J. American Academy of Dermatology Vol.19, pages 169-175, 1988, topical application of 0.1% tretinoin cream for 8 to 12 months has been found to improve clinical signs of aging skin. The side effects have been burning sensation in the eyes and mild skin irritations. US Parent application Serial No. 07/469,738 described in addition to the main subject certain compositions containing hydroxycarboxylic acids and the related ketocarboxylic acids for topical treatment of wrinkles and skin changes associated with aging. The related US application of Serial No. 07/393,749 (the priority of which is claimed in EP-A-0 413 528) described in addition to the main subject a topical treatment to alleviate or remedy warts, nail infections, age spots, wrinkles and aging related skin changes with a composition containing certain alpha hydroxyacids or the related compounds. A fungal infection, however, cannot be regarded as being "intrinsic or extrinsic aging". EP-A-273202 is directed to additives enhancing topical actions of therapeutic agents. The compositions are cosmetic or therapeutic dermatological agents, the aim of the use is to improve the skin. Likely, the therapeutic potentials of alpha hydroxy acids in this regard are also described in the Canadian Journal of Dermatology, volume 1 (5), pp. 108 to 112. EP-A-403304 discloses a shampoo composition, containing charged surfactant, which also contains 2-hydroxy alkanoic acid and a buffering agent which enhances uptake of the 2-hydroxy alkanoic acid. Use of this composition gives the benefit of increasing elasticity of the hair. SUMMARY OF THE INVENTION Accordingly, it is an object of this invention to provide methods and compositions which can alleviate signs of nail changes associated with intrinsic and/or extrinsic aging. We have now discovered that 2-hydroxycarboxylic acids and related compounds have unusual qualities which have not been disclosed in the prior art. Topical applications of compositions containing a 2-hydroxycarboxylic acid or a related compound have been found to improve cosmetic as well as clinical signs of changes in nails associated with intrinsic aging, or the damages caused by extrinsic factors such as sunlight, radiations, air pollution, wind, cold, dampness, heat, chemicals, smoke, and cigarette smoking. The signs of nail changes associated with intrinsic aging and the damages caused by extrinsic factors include thinning, fragility, splitting, lack of luster, uneven surface, and loss of flexibility and elasticity. 2-Hydroxycarboxylic acids and their related compounds which are useful for topical treatment of nail changes associated with intrinsic and/or extrinsic aging include, inter alia , 2-hydroxyethanoic acid, 2-hydroxypropanoic acid, 2-methyl 2-hydroxypropanoic acid, 2-phenyl 2-hydroxyehtanoic acid, 2-phenyl 2-methyl 2-hydroxyethanoic acid, 2-phenyl 3-hydroxypropanoic acid, 2,2-diphenyl 2-hydroxyethanoic acid, 2-hydroxybutane-1,4-dioic acid, 2,3-dihydroxybutane-1,4-dioic acid, 2-carboxy 2-hydroxypentane-1,5-dioic acid, 2-ketopropanoic acid, methyl 2-ketopropanoate, ethyl 2-ketopropanoate, and gluconolactone. Additional objects and advantages of the invention will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and the advantages of this invention may be realized and obtained by means of the compositions and methods particularly pointed out in the appended claims. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Cutaneous aging is associated with intrinsic factors with or without the additional factors of extrinsic origin. The intrinsic aging is due to internal physiologic functions and is an inherent aging process of living beings, which has not been reversible nor preventable. Extrinsic aging, on the other hand, is due to external factors such as sunlight, radiations, air pollution, wind, cold, dampness, heat, chemicals, smoke, and cigarette smoking. A modification, improvement or alleviation of the signs associated with the intrinsic or extrinsic aging of nails is also now possible in accordance with this invention. Moreover, in some cases, it may be possible to eradicate such signs of intrinsic and extrinsic aging. The signs of nail changes associated with intrinsic aging and the damages caused by extrinsic factors include thinning of nail plate; lack of luster, and uneven surface of nails; fragility and splitting of nails; and reduction of flexibility, resiliency, and elasticity of nails. We have now discovered that use of cosmetic compositions containing 2-hydroxycarboxylic acid or related compounds are effective in alleviating signs of nail changes associated with intrinsic and/or extrinsic aging. For convenience, the 2-hydroxycarboxylic acids and related compounds which may be used in accordance with this invention may be classified into three groups, namely (1) 2-hydroxycarboxylic acids, (2) 2-ketocarboxylic acids and esters thereof, and (3) other related compounds. The related compounds may include hydroxycarboxylic acids with the hydroxyl group at any position other than position 2, for example position 3, position 4 or position 5, as well as cyclic hydroxycarboxylic acids (e.g., ascorbic acid and quinic acid), and also may include ketocarboxylic acids and esters thereof. Preferred related compounds include 3-hydroxycarboxylic acids, and 2-ketocarboxylic acids and esters thereof. Group 1 The first group comprises organic carboxylic acids in which one hydroxy group is attached to the 2 position carbon atom of the acid. The generic structure of such 2-hydroxycarboxylic acids may be represented as follows: (R a ) (R b ) C (OH) COOH Where R a and R b may be the same or different and are independently selected from H, F, Cl, Br, alkyl, aralkyl or aryl group of saturated or unsaturated, isomeric or non-isomeric, straight or branched chain or cyclic form, having 1 to 29 carbon atoms, and in addition R a and R b may carry OH, CHO, COOH and alkoxy group having 1 to 9 carbon atoms. 2-Hydroxycarboxylic acids may be present as a free acid or lactone form, or in a salt form with an organic base or an inorganic alkali. 2-Hydroxycarboxylic acids may exist as stereoisomers as D, L, and DL forms when R a and R b are not identical. Typical alkyl, aralkyl and aryl groups for R a and R b include methyl, ethyl, propyl, isopropyl, butyl, pentyl, octyl, decyl, dodecyl, hexadecyl, benzyl, and phenyl, etc. 2-Hydroxycarboxylic acids of the first group may be further divided into subgroups comprising (1) alkyl hydroxycarboxylic acids, (2) aralkyl and aryl hydroxycarboxylic acids, (3) polyhydroxy-carboxylic acids, and (4) hydroxy-polycarboxylic acids. The following are representative 2-hydroxycarboxylic acids in each subgroup. (1) Alkyl Hydroxycarboxylic Acids 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 6. 2-Hydroxyhexanoic acid (C 4 H 9 ) (H) C (OH) COOH 7. 2-Hydroxyheptanoic acid (C 5 H 11 ) (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 8 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 hydroxypalmitic acid) (C 14 H 29 ) (H) C (OH) COOH 15. 2-Hydroxyoctadecanoic acid (Alpha hydroxystearic acid) (C 16 H 33 ) (H) C (OH) COOH 16. 2-Hydroxyeicosanoic acid (Alpha hydroxyarachidonic acid) (C 18 H 37 ) (H) C (OH) COOH 17. 2-Hydroxytetraeicosanoic acid (Cerebronic acid) (C 22 H 45 ) (H) C (OH) COOH 18. 2-Hydroxytetraeicosenoic acid (Alpha hydroxynervonic acid) (C 22 H 43 ) (H) C (OH) COOH (2) Aralkyl And Aryl 2-Hydroxycarboxylic Acids 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) (Cl-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 O-C 6 H 3 ) (H) C (OH) COOH 8. 2-(4'-Hydroxy-3'-methoxyphenyl) 2-hydroxyethanoic acid (4-Hydroxy-3-methoxymandelic acid) (HO-,CH 3 O-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'-Dihydroxyphenyl) 2-hydroxyethanoic acid (3,4-Dihydroxymandelic acid) (HO-,HO-C 6 H 3 ) (H) C (OH) COOH (3) Polyhydroxy-carboxylic Acids 1. 2,3-Dihydroxypropanoic acid (Glyceric acid) (HOCH 2 ) (H) C (OH) COOH 2. 2,3,4-Trihydroxybutanoic acid (Isomers; erythronic acid, threonic acid) (HOCH 2 HOCH) (H) C (OH) COOH 3. 2,3,4,5-Tetrahydroxypentanoic acid (Isomers; ribonic acid, arabinoic acid, xylonic acid, lyxonic acid) (HOCH 2 HOCH HOCH) (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, talonic acid) (HOCH 2 HOCH HOCH HOCH) (H) C (OH) COOH 5. 2,3,4,5,6,7-Hexahydroxyheptanoic acid (Isomers; glucoheptonic acid, galactoheptonic acid etc.) (HOCH 2 HOCH HOCH HOCH HOCH) (H) C (OH) COOH (4) Hydroxy-polycarboxylic Acids 1. 2-Hydroxypropane-1,3-dioic acid (Tartronic acid) (HOOC) (H) C (OH) COOH 2. 2-Hydroxybutane-1,4-dioic acid (Malic acid) (HOOC CH 2 ) (H) C (OH) COOH 3. 2,3-Dihydroxybutane-1,4-dioic acid (Tartaric acid) (HOOC HOCH) (H) C (OH) COOH 4. 2-Hydroxy-2-carboxypentane-1,5-dioic acid (Citric acid) (HOOC CH 2 ) 2 C (OH) COOH 5. 2,3,4,5-Tetrahydroxyhexane-1,6-dioic acid (Isomers; saccharic acid, mucic acid etc.) HOOC (CHOH) 4 COOH The 2-hydroxycarboxylic acids may be present in forms other than the acid, such as, for example, salts or lactones. Typical lactone forms which may be used in accordance with this invention include, for example, gluconolactone, galactonolactone, glucuronolactone, galacturonolactone, gulonolactone, ribonolactone, saccharic acid lactone, pantoyllactone, glucoheptonolactone, mannonolactone, and galactoheptonolactone. Group 2 The second group, which comprises compounds related to the 2-hydroxycarboxylic acids, includes organic carboxylic acids in which one keto group is attached to position 2 carbon atom of the acid. The generic structure of such 2-ketoacids may be represented as follows: (R c ) CO COO (R d ) wherein R c and R d can be the same or different and are each selected from H, alkyl, aralkyl or aryl group of saturated or unsaturated, isomeric or non-isomeric, straight or branched chain or cyclic form, having 1 to 29 carbon atoms, and in addition R c may carry F, Cl, Br, I, OH, CHO, COOH and alkoxy group having 1 to 9 carbon atoms. The alpha 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 c and R d include methyl, ethyl, propyl, 2-propyl, butyl, pentyl, hexyl, octyl, dodecyl, hexadecyl, benzyl and phenyl. The representative 2-ketocarboxylic acids and their esters of the second group are listed below: 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 (Benzoylformic acid) C 6 H 5 CO COOH 8. Methyl 2-phenyl-2-ketoethanoate (Methyl benzoylformate) C 6 H 5 CO COOCH 3 9. Ethyl 2-phenyl-2-ketoethanoate (Ethyl benzoylformate) 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-ketopropanoate (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 11 CO COOH 17. 2-Ketooctanoic acid C 6 H 13 CO COOH 18. 2-Ketododecanoic acid C 10 H 21 CO COOH 19. Methyl 2-ketooctanoate C 6 H 14 CO COOCH 3 Group 3 The third group, which also comprises related compounds, includes, inter alia , hydroxycarboxylic acids where the hydroxy is at a position other than position 2, and cyclic hydroxycarboxylic acids. The members of this group, which are more conveniently identified by name than by generic structures, include ascorbic acid, quinic acid, isocitric acid, tropic acid (2-phenyl 3-hydroxypropanoic acid), trethocanic acid, 3-chlorolactic acid, citramalic acid, agaricic acid, aleuritic acid, pantoic acid, lactobionic acid and hexulosonic acid. Specific Compositions While 2-hydroxycarboxylic acids and related compounds are therapeutically effective for topical treatment to improve or alleviate signs of nail changes associated with intrinsic aging and/or photoaging, certain compounds of the instant invention are more potent than others. In selecting a particular compound of the present invention two factors, namely (a) potency and (b) concentration have to be considered. If rapid results are preferred in certain cases, most potent compounds with highest and safe concentrations may be used. Under such conditions the treatment time is substantially shortened with good to excellent clinical results. Generally, such treatment has to be carried out under supervision by a dermatologist or trained professional in the office, medical center, skin care center, or beauty salon etc. Such procedure or treatment may include micro and semimicro peels, epidermolysis or superficial peel, and dermolysis or deeper peel. Examples of more potent 2-hydroxycarboxylic acids and related compounds to be formulated in specific compositions include 2-hydroxyethanoic acid, 2-hydroxypropanoic acid, 2-methyl 2-hydroxypropanoic acid, 2-phenyl 2-hydroxyethanoic acid, 2,2-diphenyl 2-hydroxyethanoic acid, 2-phenyl 2-methyl 2-hydroxyethanoic acid, 2-phenyl 3-hydroxypropanoic acid, 2-ketopropanoic acid, methyl 2-ketopropanoate and ethyl 2-ketopropanoate. The concentration of 2-hydroxycarboxylic acid or the related compound used in such specific composition may range from an intermediate to a full strength, therefore the dispensing and the application require special handling and procedures. If the 2-hydroxycarboxylic acid or the related compound at full strength (usually 85-100%) is a liquid form at room temperature such as 2-hydroxypropanoic acid, 2-ketopropanoic acid, methyl 2-ketopropanoate and ethyl 2-ketopropanoate, the liquid compound with or without a gelling agent is directly dispensed as 0.5 to 1 ml aliquots in small vials. If the 2-hydroxycarboxylic acid or the related compound at full strength is a crystalline or solid form at room temperature such as 2-hydroxyethanoic acid, 2-methyl 2-hydroxypropanoic acid, 2-phenyl 2-hydroxyethanoic acid, 2,2-diphenyl 2-hydroxyethanoic acid and 2-phenyl 3-hydroxypropanoic acid, the crystalline or solid compound is first dissolved in a minimal amount of vehicle or vehicle system prepared from water, ethanol, propylene glycol and/or butylene glycol with or without a gelling agent. For example, 2-hydroxyethanoic acid 70 g is dissolved in water 30 ml, and the 70% strength solution thus obtained is dispensed as 0.5 to 1 ml aliquots in small vials. If a gelling agent is used 0.1 to 2% of hydroxyethyl cellulose, methyl cellulose, hydroxypropyl cellulose, chitosan, carbomer, or polyquaternium-10 may be incorporated into the above solution. To formulate an intermediate strength (usually 20-50%), 2-hydroxycarboxylic acid or the related compound either a liquid or solid form at room temperature is first dissolved in a vehicle or vehicle system prepared from water, acetone, ethanol, propylene glycol and/or butylene glycol. For example, 2-hydroxyethanoic acid or 2-ketopropanoic acid 30 g is dissolved in ethanol 56 g and propylene glycol 14 g, and the 30% strength solution thus obtained is dispensed as 7 to 14 ml aliquots in dropper bottles. General Preparation of Compositions Most compositions of the instant invention may be formulated as solution, gel, lotion, cream, ointment, or other pharmaceutically acceptable form. To prepare a composition in solution form for general use, at least one 2-hydroxycarboxylic acid or related compound is dissolved in a solution prepared from ethanol, water, propylene glycol, butylene glycol, acetone or other pharmaceutically acceptable vehicle. The concentration of the 2-hydroxycarboxylic acid or related compound may range from 0.1 to 100 percent, the preferred concentration ranges being from about 2 to about 25 percent for home use, with higher ranges, e.g., from about 70 to about 100 percent being acceptable for office use where professional supervision is provided. Thus, such concentrations can also range from about 25 to about 50 percent and from about 50 to about 70 percent, with the proviso that concentrations of about 25 percent or more generally requiring profession supervision. In the preparation of a composition in lotion, cream or ointment form, at least one of 2-hydroxycarboxylic acids or related compounds is initially dissolved in a solvent such as water, ethanol, butylene glycol, and/or propylene glycol. The solution thus prepared is then mixed in a conventional manner with commonly available cream or ointment base such as hydrophilic ointment or petrolatum. The concentrations of 2-hydroxycarboxylic acids or related compounds used in the compositions are the same as described above. A typical gel composition of the instant invention is formulated by dissolving at least one of 2-hydroxycarboxylic acids or related compounds in a vehicle prepared from ethanol, water, butylene glycol, and/or propylene glycol. A gelling agent such as xanthan gum, polyquaternium-10, methyl cellulose, ethyl cellulose, hydroxyethylcellulose, hydroxypropylcellulose, chitosan, hydroxypropylmethylcellulose, ammoniated glycyrrhizinate or carbomer is then added to the solution with agitation. The preferred concentration of the gelling agent may range from 0.1 to 2 percent by weight of the total composition. The following are illustrative examples of formulations and compositions according to this invention. Although the examples utilize only selected compounds and formulations, it should be understood that the following examples are illustrative and not limited. Therefore, any of the aforementioned 2-hydroxycarboxylic acids and related compounds may be substituted according to the teachings of this invention in the following examples. EXAMPLE 1 A typical solution composition containing 2-hydroxycarboxylic acid or the related compound may be formulated as follows. 2-Hydroxyethanoic acid (glycolic acid) crystals 7 g is dissolved in water 50 ml and propylene glycol 15 ml. Ethanol is added to the solution until the total volume is 100 ml. The composition thus prepared contains 7% w/v 2-hydroxyethanoic acid. EXAMPLE 2 A typical gel composition containing 2-hydroxycarboxylic acid or the related compound may be formulated as follows. 2-Hydroxypropanoic acid (DL-lactic acid) USP grade 5 g is dissolved in water 60 ml and butylene glycol 10 ml, and chitosan or polyquaternium-10 0.3 g is added with stirring. Ethanol is added to the mixture until the volume is 100 ml. The mixture is stirred until a uniform gel is obtained. The thin gel thus obtained contains 5% 2-hydroxypropanoic acid. EXAMPLE 3 A typical oil-in-water emulsion containing 2-hydroxycarboxylic acid or the related compound may be formulated as follows. 2-Methyl 2-hydroxypropanoic acid (methyllactic acid) crystals 10 g is dissolved in water 20 ml and concentrated ammonium hydroxide 2 ml is added to the solution. The solution is mixed with enough hydrophilic ointment USP to make a total weight of 100 g. The cream thus formulated contains 10% 2-methyl 2-hydroxypropanoic acid. EXAMPLE 4 A typical water-in-oil emulsion containing 2-hydroxycarboxylic acid or the related compound may be formulated as follows. Gluconolactone 7 g is dissolved in water 12 ml and concentrated ammonium hydroxide 0.5 ml is added to the solution. The solution is mixed with enough water-in-oil emulsion to make a total weight of 100 g. The water non-washable cream thus formulated contains 7% gluconolactone. EXAMPLE 5 A typical ointment containing 2-hydroxycarboxylic acid or the related compound may be formulated as follows. 2-Phenyl 2-hydroxyethanoic acid (mandelic acid) crystals 10 g is dissolved in 10 ml ethanol, and the solution thus formed is mixed with mineral oil 35 g and enough white petrolatum to make a total weight of 100 g. The ointment thus formulated contains 10% 2-phenyl 2-hydroxyethanoic acid. EXAMPLE 6 A specific preparation containing a full strength or a high concentration of 2-hydroxycarboxylic acid or the related compound may be formulated and dispensed as follows. If 2-hydroxycarboxylic acid or the related compound at full strength is a liquid form at room temperature such as 2-hydroxypropanoic acid, 2-ketopropanoic acid, methyl 2-ketopropanoate and ethyl 2-ketopropanoate, the compound is directly dispensed as 0.5 to 1 ml aliquots in small vials. If the compound is a crystalline or solid form, such as 2-hydroxyethanoic acid, 2-methyl 2-hydroxypropanoic acid, 2-phenyl 2-hydroxyethanoic acid, 2-phenyl 3-hydroxypropanoic acid, 2-phenyl 2-methyl 2-hydroxyethanoic acid and 2,2-diphenyl 2-hydroxyethanoic acid, the compound is first dissolved in minimal amount of an appropriate vehicle system selected from water, ethanol, propylene glycol and butylene glycol with or without a gelling agent. For example, 2-hydroxyethanoic acid 70 g is dissolved in water 30 ml, and 70% strength 2-hydroxyethanoic acid with or without addition of 0.5% chitosan or polyquaternium-10 is dispensed as 1 to 5 ml aliquots in small vials. EXAMPLE 7 A typical preparation containing an intermediate strength of 2-hydroxycarboxylic acid or the related compound may be formulated as follows. Malic acid, tartaric acid or citric acid 35 g is dissolved in water 60 ml and propylene glycol 5 ml. The 35% strength solution thus prepared is dispensed as 5 to 10 ml aliquots in dropper bottles. TEST RESULTS (1) Biologic and Pharmacologic Actions The skin may be classified into two major parts; dermis and epidermis. The dermis contains blood vessels, nerves, collagen, elastin etc, and fibroblast cells in the dermis are responsible for the biosynthesis of collagen and elastin. The epidermis contains nerves but no collagen, elastin, nor blood vessels. The epidermis is further divided into two distinct zones; malpighian layer and horny layer. The malpighian layer, a living tissue, is further divided into basal, spinous, and granular layers. The horny layer, a dead tissue, is also called stratum corneum. In the natural process, basal cells in the basal layer move outward through the spinous and granular layers to become dead cells called corneocytes, in the stratum corneum. The stratum corneum consists of approximately 14 layers of corneocytes. In normal skin it takes about 14 days for the basal cells to move from the basal layer to the end of the granular layer and to become corneocytes, and another 14 days to reach the outermost layer of the stratum corneum. This process of forming corneocytes is called keratinization, and stratum corneum, nail, and hair are the natural products produced by such process. The stratum corneum is the skin tissue that one feels when touching the skin. Usually, it takes about 28 days for cells of the basal layer to move outward to the surface in the course of making new skin. We have found that compositions containing low concentrations of 2-hydroxycarboxylic acid or the related compound, when applied topically to the skin, diminish corneocyte cohesion in the stratum corneum. This effect predominantly occurs among corneocyte cells at inner levels of the stratum corneum, i.e. near the junction to the granular layer, and there is no effect among corneocyte cells at outer layers in the stratum corneum. Therefore, 2-hydroxycarboxylic acids and related compounds are not typical keratolytics such as strong acids, strong alkalis, thiols, urea and lithium salts which cause disaggregation of corneocyte cells in the outer layers of the stratum corneum. We have also discovered that compositions containing intermediate to high concentrations of 2-hydroxycarboxylic acid or the related compound, when topically applied to the skin, cause profound beneficial effects in the dermis as well as the epidermis of the skin. The skin becomes thicker and plump as measured clinically by caliper and micrometer techniques. Histometric techniques using microscopic analysis of tissue biopsy specimens confirm that new and more collagen and elastic fibers have been biosynthesized in the dermis. The biologic and pharmacologic actions of 2-hydroxycarboxylic acid or the related compound suggest that topical application of the composition should improve or alleviate signs of nail changes associated with intrinsic and/or extrinsic aging. (2) Nail Treatments Compositions containing 2-hydroxycarboxylic acid or the related compound at intermediate concentrations, preferably from 8 to 20%, for nail care and treatment were formulated according to the examples. A solution or thin gel form thus prepared was topically applied twice daily to edges, surface and base of affected nail plates. After a few months of such treatment, the signs of nail changes associated with intrinsic and extrinsic aging started to improve noticeably. The nail looked glossy and felt smooth on the surface. The flexibility and elasticity of the nail after the treatment also increased. Brittleness diminished and the occurrence of terminal nail splitting became rare. It will be apparent to those skilled in the art that various modifications and variations can be made to the compositions of matter and methods of this invention. Thus, it is intended that the present invention covers such modifications and variations.

Claims: Use of a cosmetic composition comprising one or more 2-hydroxycarboxylic acids, 2-ketoacids, or related compounds, said related compounds selected from the group consisting of ascorbic acid, quinic acid, isocitric acid, tropic acid, trethocanic acid, 3-chlorolactic acid, cerebronic acid, citramalic acid, agaricic acid, aleuritic acid, pantoic acid, lactobionic acid and hexulosonic acid, in a topically acceptable vehicle for topical application to the nail of humans or animals for alleviating signs of nail changes associated with intrinsic and/or extrinsic aging. Use of a composition as claimed in claim 1, wherein said extrinsic aging include any or plural of sunlight; radiations; air pollution; wind; cold; dampness; heat; chemicals; smoke; cigarette smoking. Use of a composition as claimed in any of claims 1 or 2, wherein the signs of nail changes associated with intrinsic and/or extrinsic aging include thinning, fragility, splitting, lack of luster, uneven surface, loss of flexibility, loss of elasticity, and loss of resiliency. Use of a composition as claimed in any of claims 1-3, wherein said 2-hydroxycarboxylic acid may be represented by a generic structure of: (R a ) (R b ) C (OH) COOH wherein R a and R b may be the same or different and are independently selected from H, F, Cl, Br, alkyl, aralkyl or aryl group of saturated or unsaturated, isomeric or non-isomeric, straight or branched chain or cyclic form, having 1 to 29 carbon atoms, and in addition R a and R b may carry OH, CHO, COOH and alkoxy group having 1 to 9 carbon atoms, said 2-hydroxycarboxylic acid may be present as a free acid or lactone form, or in a salt form with an organic base or an inorganic alkali, and as stereoisomers as D, L, and DL forms when R a and R b are not identical. Use of a composition as claimed in claim 4, wherein said 2-hydroxycarboxylic acid is in salt or lactone form, preferably selected from the group consisting of gluconolactone, galactonolactone, glucuronolactone, galactrononolactone, gulonolactone, ribonolactone, saccharic acid lactone, pantoyllactone, glucoheptonolactone, mannonolactone, and galactoheptonolactone. Use of a composition as claimed in claim 4, wherein said 2-hydroxycarboxylic acid is an alkyl hydroxycarboxylic acid, preferably selected from the group consisting of 2-Hydroxyethanoic acid (Glycolic acid), 2-Hydroxypropanoic acid (Lactic acid), 2-Methyl 2-hydroxypropanoic acid (Methyllactic acid), 2-Hydroxybutanoic acid, 2-Hydroxypentanoic acid, 2-Hydroxyhexanoic acid, 2-Hydroxyheptanoic acid, 2-Hydroxyoctanoic acid, 2-Hydroxynonanoic acid, 2-Hydroxydecanoic acid, 2-Hydroxyundecanoic acid, 2-Hydroxydodecanoic acid (Alpha hydroxylauric acid), 2-Hydroxytetradecanoic acid (Alpha hydroxymyristic acid), 2-Hydroxyhexadecanoic acid (Alpha hydroxypalmitic acid), 2-Hydroxyoctadecanoic acid (Alpha hydroxystearic acid), 2-Hydroxyeicosanoic acid (Alpha hydroxyarachidonic acid), 2-Hydroxytetraeicosanoic acid (Cerebronic acid), and 2-Hydroxytetraeicosenoic acid (Alpha hydroxynervonic acid). Use of a composition as claimed in claim 4, wherein said 2-hydroxycarboxylic acid is an aralkyl or aryl 2-hydroxycarboxylic acid, preferably selected from the group consisting of 2-Phenyl 2-hydroxyethanoic acid (Mandelic acid), 2,2-Diphenyl 2-hydroxyethanoic acid (Benzilic acid), 3-Phenyl 2-hydroxypropanoic acid (Phenyllactic acid), 2-Phenyl 2-methyl 2-hydroxyethanoic acid (Atrolactic acid), 2-(4'-Hydroxyphenyl) 2-hydroxyethanoic acid, 2-(4'-Chlorophenyl) 2-hydroxyethanoic acid, 2-(3'-Hydroxy-4'-methoxyphenyl) 2-hydroxyethanoic acid, 2-(4'-Hydroxy-3'-methoxyphenyl) 2-hydroxyethanoic acid, 3-(2'-Hydroxyphenyl) 2-hydroxypropanoic acid, 3-(4'-Hydroxyphenyl) 2-hydroxypropanoic acid, and 2-(3',4'-Dihydroxyphenyl) 2-hydroxyethanoic acid. Use of a composition as claimed in claim 4, wherein said 2-hydroxycarboxylic acid is a polyhydroxycarboxylic acid or hydroxypolycarboxylic acid, preferably selected from the group consisting of 2,3-Dihydroxypropanoic acid (Glyceric acid), 2,3,4-Trihydroxybutanoic acid (Isomers; erythronic acid, threonic acid), 2,3,4,5-Tetrahydroxypentanoic acid (Isomers; ribonic acid, arabinoic acid, xylonic acid, lyxonic acid), 2,3,4,5,6-Pentahydroxyhexanoic acid (Isomers; allonic acid, altronic acid, gluconic acid, mannoic acid, gulonic acid, idonic acid, galactonic acid, talonic acid), 2,3,4,5,6,7-Hexahydroxyheptanoic acid (Isomers; glucoheptonic acid, galactoheptonic acid etc.) and Hydroxypropane-1,3-dioic acid (Tartronic acid), 2-Hydroxybutane-1,4-dioic acid (Malic acid), 2,3-Dihydroxybutane-1,4-dioic acid (Tartaric acid), 2-Hydroxy-2-carboxypentane-1,5-dioic acid (Citric acid), 2,3,4,5-Tetrahydroxyhexane-1,6-dioic acid (Isomers; saccharic acid, mucic acid, etc.). Use of a composition as claimed in any of claims 1-3, wherein said related compound comprises a 2-ketoacid of the generic formula: (R c ) CO COO (R d ) wherein R c and R d may be the same or different and are independently selected from H, alkyl, aralkyl or aryl group of saturated or unsaturated, isomeric or non-isomeric, straight or branched chain or cyclic form, having 1 to 29 carbon atoms, and in addition R c may carry F, Cl, Br, I, OH, CHO, COOH and alkoxy group having 1 to 9 carbon atoms, said alpha ketoacid existing as a free acid or an ester form, or in a salt form with an organic base or an inorganic alkali. Use of a composition as claimed in claim 9, wherein said 2-ketoacid is selected from the group consisting of 2-Ketoethanoic acid (Glyoxylic acid), Methyl 2-ketoethanoate, 2-Ketopropanoic acid (Pyruvic acid), Methyl 2-ketopropanoate (Methyl pyruvate), Ethyl 2-ketopropanoate (Ethyl pyruvate), Propyl 2-ketopropanoate (Propyl pyruvate), 2-Phenyl-2-ketoethanoic acid (Benzoylformic acid), Methyl 2-phenyl-2-ketoethanoate (Methyl benzoylformate), Ethyl 2-phenyl-2-ketoethanoate (Ethyl benzoylformate), 3-Phenyl-2-ketopropanoic acid (Phenylpyruvic acid), Methyl 3-phenyl-2-keotpropanoate (Methyl phenylpyruvate), Ethyl 3-phenyl-2-ketopropanoate (Ethyl phenylpyruvate), 2-Ketobutanoic acid, 2-Ketopentanoic acid, 2-Ketohexanoic acid, 2-Ketoheptanoic acid, 2-Ketooctanoic acid, 2-Ketododecanoic acid, and Methyl 2-ketooctanoate. Use of a composition as claimed in claim 10 wherein said related compound is a 2-ketocarboxylic acid ester. Use of a composition as claimed in any of claims 1-3, wherein said 2-hydroxycarboxylic acid or related compound is selected from the group consisting of isocitric acid, methyllactic acid, mandelic acid, quinic acid or quinolactone, malic acid, ethyl pyruvate, tropic acid, ascorbic acid or ascorbolactone, benzilic acid, ribonic acid or ribonolactone, saccharic acid or saccharolactone, mucic acid or mucolactone, citramalic acid, galactonic acid or galactonolactone, gulonic acid or gulonolactone, glucoheptonic acid or glucoheptonolactone, pantoic acid or pantolactone, phenyllactic acid, gluconic acid or gluconolactone. Use of one or more 2-hydroxycarboxylic acids, 2-ketoacids, or related compounds, said related compunds selected from the group consisting of ascorbic acid, quinic acid, isocitric acid, tropic acid, trethocanic acid, 3-chlorolactic acid, cerebronic acid, citramalic acid, agaricic acid, aleuritic acid, pantoic acid, lactobionic acid and hexulosonic acid, together with a vehicle acceptable for topical application to the nail of humans or animals, for the preparation of a therapeutic composition for alleviating signs of nail changes associated with intrinsic and/or extrinsic aging. Use as claimed in claim 13, wherein said extrinsic aging include any or plural of sunlight; radiations; air pollution; wind; cold; dampness; heat; chemicals; smoke; cigarette smoking. Use as claimed in any of claims 13 or 14, wherein the signs of nail changes associated with intrinsic and/or extrinsic aging include thinning, fragility, splitting, lack of luster, uneven surface, loss of flexibility, loss of elasticity, and loss of resiliency. Use as claimed in any of claims 13-15, wherein said 2-hydroxycarboxylic acid may be represented by a generic structure of: (R a ) (R b ) C (OH) COOH wherein R a and R b may be the same or different and are independently selected from H, F, Cl, Br, alkyl, aralkyl or aryl group of saturated or unsaturated, isomeric or non-isomeric, straight or branched chain or cyclic form, having 1 to 29 carbon atoms, and in addition R a and R b may carry OH, CHO, COOH and alkoxy group having 1 to 9 carbon atoms, said 2-hydroxycarboxylic acid may be present as a free acid or lactone form, or in a salt form with an organic base or an inorganic alkali, and as stereoisomers as D, L, and DL forms when R a and R b are not identical. Use as claimed in claim 16, wherein said 2-hydroxycarboxylic acid is in salt or lactone form, preferably selected from the group consisting of gluconolactone, galactonolactone, glucuronolactone, galactrononolactone, gulonolactone, ribonolactone, saccharic acid lactone, pantoyllactone, glucoheptonolactone, mannonolactone, and galactoheptonolactone. Use as claimed in claim 16, wherein said 2-hydroxycarboxylic acid is an alkyl hydroxycarboxylic acid, preferably selected from the group consisting of 2-Hydroxyethanoic acid (Glycolic acid), 2-Hydroxypropanoic acid (Lactic acid), 2-Methyl 2-hydroxypropanoic acid (Methyllactic acid), 2-Hydroxybutanoic acid, 2-Hydroxypentanoic acid, 2-Hydroxyhexanoic acid, 2-Hydroxyheptanoic acid, 2-Hydroxyoctanoic acid, 2-Hydroxynonanoic acid, 2-Hydroxydecanoic acid, 2-Hydroxyundecanoic acid, 2-Hydroxydodecanoic acid (Alpha hydroxylauric acid), 2-Hydroxytetradecanoic acid (Alpha hydroxymyristic acid), 2-Hydroxyhexadecanoic acid (Alpha hydroxypalmitic acid), 2-Hydroxyoctadecanoic acid (Alpha hydroxystearic acid), 2-Hydroxyeicosanoic acid (Alpha hydroxyarachidonic acid), 2-Hydroxytetraeicosanoic acid (Cerebronic acid), and 2-Hydroxytetraeicosenoic acid (Alpha hydroxynervonic acid). Use as claimed in claim 16, wherein said 2-hydroxycarboxylic acid is an aralkyl or aryl 2-hydroxycarboxylic acid, preferably selected from the group consisting of 2-Phenyl 2-hydroxyethanoic acid (Mandelic acid), 2,2-Diphenyl 2-hydroxyethanoic acid (Benzilic acid), 3-Phenyl 2-hydroxypropanoic acid (Phenyllactic acid), 2-Phenyl 2-methyl 2-hydroxyethanoic acid (Atrolactic acid), 2-(4'-Hydroxyphenyl) 2-hydroxyethanoic acid, 2-(4'-Chlorophenyl) 2-hydroxyethanoic acid, 2-(3'-Hydroxy-4'-methoxyphenyl) 2-hydroxyethanoic acid, 2(4'-Hydroxy-3'-methoxyphenyl) 2-hydroxyethanoic acid, 3-(2'-Hydroxyphenyl) 2-hydroxypropanoic acid, 3-(4'-Hydroxyphenyl) 2-hydroxypropanoic acid, and 2-(3',4'-Dihydroxyphenyl) 2-hydroxyethanoic acid. Use as claimed in claim 16, wherein said 2-hydroxycarboxylic acid is a polyhydroxycarboxylic acid or hydroxypolycarboxylic acid, preferably selected from the group consisting of 2,3-Dihydroxypropanoic acid (Glyceric acid), 2,3,4-Trihydroxybutanoic acid (Isomers; erythronic acid, threonic acid), 2,3,4,5-Tetrahydroxypentanoic acid (Isomers; ribonic acid, arabinoic acid, xylonic acid, lyxonic acid), 2,3,4,5,6-Pentahydroxyhexanoic acid (Isomers; allonic acid, altronic acid, gluconic acid, mannoic acid, gulonic acid, idonic acid, galactonic acid, talonic acid), 2,3,4,5,6,7-Hexahydroxyheptanoic acid (Isomers; glucoheptonic acid, galactoheptonic acid etc.) and Hydroxypropane-1,3-dioic acid (Tartronic acid), 2-Hydroxybutane-1,4-dioic acid (Malic acid), 2,3-Dihydroxybutane-1,4-dioic acid (Tartaric acid), 2-Hydroxy-2-carboxypentane-1,5-dioic acid (Citric acid), 2,3,4,5-Tetrahydroxyhexane-1,6-dioic acid (Isomers; saccharic acid, mucic acid, etc.). Use as claimed in any of claims 13-15, wherein said related compound comprises a 2-ketoacid of the generic formula: (R c ) CO COO (R d ) wherein R c and R d may be the same or different and are independently selected from H, alkyl, aralkyl or aryl group of saturated or unsaturated, isomeric or non-isomeric, straight or branched chain or cyclic form, having 1 to 29 carbon atoms, and in addition R c may carry F, Cl, Br, I, OH, CHO, COOH and alkoxy group having 1 to 9 carbon atoms, said alpha ketoacid existing as a free acid or an ester form, or in a salt form with an organic base or an inorganic alkali. Use as claimed in claim 21, wherein said 2-ketoacid is selected from the group consisting of 2-Ketoethanoic acid (Glyoxylic acid), Methyl 2-ketoethanoate, 2-Ketopropanoic acid (Pyruvic acid), Methyl 2-ketopropanoate (Methyl pyruvate), Ethyl 2-ketopropanoate (Ethyl pyruvate), Propyl 2-ketopropanoate (Propyl pyruvate), 2-Phenyl-2-ketoethanoic acid (Benzoylformic acid), Methyl 2-phenyl-2-ketoethanoate (Methyl benzoylformate), Ethyl 2-phenyl-2-ketoethanoate (Ethyl benzoylformate), 3-Phenyl-2-ketopropanoic acid (Phenylpyruvic acid), Methyl 3-phenyl-2-keotpropanoate (Methyl phenylpyruvate), Ethyl 3-phenyl-2-ketopropanoate (Ethyl phenylpyruvate), 2-Ketobutanoic acid, 2-Ketopentanoic acid, 2-Ketohexanoic acid, 2-Ketoheptanoic acid, 2-Ketooctanoic acid, 2-Ketododecanoic acid, and Methyl 2-ketooctanoate. Use as claimed in claim 22 wherein said related compound is a 2-ketocarboxylic acid ester. Use as claimed in any of claims 13-15, wherein said 2-hydroxycarboxylic acid or related compound is selected from the group consisting of isocitric acid, methyllactic acid, mandelic acid, quinic acid or quinolactone, malic acid, ethyl pyruvate, tropic acid, ascorbic acid or ascorbolactone, benzilic acid, ribonic acid or ribonolactone, saccharic acid or saccharolactone, mucic acid or mucolactone, citramalic acid, galactonic acid or galactonolactone, gulonic acid or gulonolactone, glucoheptonic acid or glucoheptonolactone, pantoic acid or pantolactone, phenyllactic acid, gluconic acid or gluconolactone. Use of a composition as claimed in any of claims 1 to 4, wherein said 2-hydroxy-carboxylic acid, 2-ketoacid, or related compounds, is 2-hydroxyethanoic acid (glycolic acid). Use of a composition as claimed in any of claims 1 to 4, wherein said 2-hydroxy-carboxylic acid, 2-ketoacid, or related compounds, is 2-hydroxypropanoic acid (lactic acid). Use of a composition as claimed in any of claims 1 to 4, wherein said 2-hydroxy-carboxylic acid, 2-ketoacid, or related compounds, is 2-hydroxy-2-carboxypentane-1,5-dioic acid (citric acid). Use of a composition as claimed in any of claims 1 to 4, wherein said 2-hydroxy-carboxylic acid, 2-ketoacid, or related compounds, is 2-methyl 2-hydroxypropanoic acid (methyllactic acid). Use of a composition as claimed in any of claims 1 to 4, wherein said 2-hydroxy-carboxylic acid, 2-ketoacid, or related compounds, is gluconolactone. Use of a composition as claimed in any of claims 1 to 4, wherein said 2-hydroxy-carboxylic acid, 2-ketoacid, or related compounds, is quinic acid, ribonolactone, malic acid, mandelic acid, benzilic acid, galactonolactone, ascorbic acid, ethyl pyruvate or tropic acid. Use as claimed in any of claims 13-17, wherein said 2-hydroxycarboxylic acids, 2-ketoacids, or related compounds, is 2-hydroxyethanoic acid (glycolic acid). Use as claimed in any of claims 13-17, wherein said 2-hydroxycarboxylic acid, 2-ketoacid, or related compounds, is 2-hydroxypropanoic acid (lactic acid). Use as claimed in any of claims 13-17, wherein said 2-hydroxycarboxylic acid, 2-ketoacid, or related compounds, is 2-hydroxy-2-carboxypentane-1,5-dioic acid (citric acid). Use as claimed in any of claims 13-17, wherein said 2-hydroxycarboxylic acid, 2-ketoacid, or related compounds, is 2-methyl 2-hydroxypropanoic acid (methyllactic acid). Use as claimed in any of claims 13-17, wherein said 2-hydroxycarboxylic acid, 2-ketoacid, or related compounds, is gluconolactone. Use as claimed in any of claims 13-17, wherein said 2-hydroxycarboxylic acid, 2-ketoacid, or related compounds, is quinic acid, ribonolactone, malic acid, mandelic acid, benzilic acid, galactonolactone, ascorbic acid, ethyl pyruvate and tropic acid.

Inventors: VAN SCOTT EUGENE J DR, YU RUEY J DR, VAN SCOTT, EUGENE J., DR., YU, RUEY J., DR.
Applicants: SCOTT EUGENE J VAN, YU RUEY J, VAN SCOTT, EUGENE J., DR., YU, RUEY J., DR.
Application year: 1992
Main classification: A61K7
IPC codes: A61K8, A61Q3, A61Q19, A61Q17, A61K31, A61Q5