Aminosulfonic acid compounds for promoting desquamation of the skin

Abstract

Aminosulfonic acid compounds having the structural formula (I): 1

Description

BACKGROUND OF THE INVENTION

[0002] 1. Technical Field of the Invention

[0003] The invention relates to the use, in a composition or for the manufacture of a composition, of at least one aminosulfonic derivative, the derivative or the composition being intended to promote desquamation of the skin and/or to stimulate epidermal renewal and/or to combat aging of the skin.

[0004] The invention also relates to a non-therapeutic regime or regimen for treating the skin which is intended to promote desquamation and/or to stimulate epidermal renewal and/or to combat aging of the skin, which comprises topically applying to the skin a composition comprising at least one aminosulfonic derivative.

[0005] 2. Description of Related/Prior Art

[0006] Aging of the skin results from two separate and independent processes which involve intrinsic or extrinsic factors.

[0007] Intrinsic or chronobiological aging corresponds to “normal” aging or physiological age-related aging.

[0008] Extrinsic aging corresponds to aging caused in general by the environment and more particularly to light-induced aging caused by exposure to the sun, to light or to any other radiation (EP-A2-0 815 840, Kligman, A. M. et al., Journal of Cutaneous Aging and Cosmetic Dermatology, Vol. 1, No. 1, pp. 5-12 (1988)).

[0009] The present invention relates to intrinsic or physiological aging of the skin and also to extrinsic aging of the skin.

[0010] Aging of the skin is generally reflected by the appearance of wrinkles and fine lines, by yellowing of the skin which develops a wizened appearance accompanied by the appearance of pigmentation marks, by disorganization of the elastin and collagen fibers resulting in a loss of elasticity, suppleness and firmness, or by the appearance of telangiectasias.

[0011] The changes in the skin due to intrinsic aging are the consequence of a genetically programmed senescence involving endogenous factors. This intrinsic aging is especially reflected by a slowing-down in the renewal of the epidermal cells and the appearance of wrinkles or fine lines.

[0012] In contrast, extrinsic aging results, in the dermis, from the degradation of the collagen fibers, the consequence of which is especially clinical impairments such as heavy wrinkles and the formation of a flaccid and weather-beaten skin.

[0013] Desquamation is a natural phenomenon associated with the fact that the epidermis, which constitutes the upper layer of the skin, is in constant regeneration.

[0014] The human epidermis consists of several layers of cells in which mainly four types of cells are found: keratinocytes, which form the vast majority, melanocytes, Langerhans cells and Merkel cells. The distribution of these cells in several superposed layers explains the stratified nature of the epidermis.

[0015] The epidermis is conventionally divided into a basal layer of keratinocytes which constitutes the germinative layer of the epidermis, a “spiney” layer consisting of several layers of polyhedric cells arranged on the germinative cells, a “granulous” layer consisting of flattened cells containing distinct cytoplasmic inclusions, keratohyalin grains, and finally an upper layer known as the horny layer (or stratum corneum), consisting of keratinocytes at the final stage of their differentiation, known as corneocytes. The corneocytes are mummified anuclear cells which are derived from the keratinocytes and are removed by desquamation. This loss at the surface is compensated for by the migration of cells from the basal layer towards the surface of the epidermis. This constitutes a perpetual renewal of the epidermis. A forced removal of the horny layer accelerates the renewal and makes it possible to combat aging of the skin.

[0016] The corneocytes are mainly composed of a fibrous matrix containing cytokeratins, surrounded by a very strong structure 15 nm thick, known as the horny or cornified envelope. The stacking of these corneocytes constitutes the horny layer which is responsible for the barrier function of the epidermis. During the normal process of desquamation, the uppermost corneocytes become detached from the surface of the epidermis.

[0017] Intercellular structures derived from desmosomes, known as corneosomes or corneodesmosomes, have been described in the horny layer. Recent studies have shown their major importance in intercorneocytic cohesion and also in the desquamation process.

[0018] Corneodesmosine, which has been characterized elsewhere in EP-A-0,972,042 by the Applicant, is a protein of the horny layer of the epidermis which is involved in intercorneocytic cohesion and which is a constituent of the corneodesmosomes.

[0019] In the horny layer, a close correlation exists between cell dissociation and the proteolysis of certain corneodesmosomal components, for instance desmoglein I and corneodesmosine. Several serine proteases of trypsin or chymotrypsin type appear to be involved in the proteolysis of corneodesmosomes, such as, in particular, proteases of chymotrypsin-like or trypsin-like type (Lundstrom A., Egelrud T., The Journal of Investigative Dermatology; 1988, 91:340-343 and 1990, 84:216-220).

[0020] The prior art discloses various agents for combating aging of the skin, in particular by promoting desquamation, that is to say the removal of the “dead” cells at the surface of the horny layer of the epidermis. This “desquamating” property is also referred to, erroneously, as a keratolytic property.

[0021] Thus, U.S. Pat. No. 4,603,146 describes the use of retinoic acid and its derivatives in cosmetic compositions for combating aging of the skin.

[0022] Moreover, many patents and publications (see for example EP-A-413,528) and also many commercial cosmetic compositions teach the use of α-hydroxy acids, for instance lactic acid, glycolic acid or citric acid, for treating aging of the skin.

[0023] Finally, β-hydroxy acids and more especially salicylic acid and derivatives thereof are known for their desquamating properties (see WO-A-93/10756 and U.S. Pat. No. 4,767, 750).

[0024] The fact remains that the desire to conserve a youthful appearance always leads to the incessant search for novel compounds and/or novel compositions for maintaining and/or improving the appearance of the skin.

[0025] Certain cosmetic active agents are capable of stimulating the degradation of corneodesmosomal proteins and thus desquamation, undoubtedly, as has been seen previously, by promoting the activity of proteases involved in this process.

[0026] In this perspective, EP-A2-0,852,949 (Shiseido) has disclosed that α-amino acid derivatives of glycine type promote the degradation of desmoglein (corneodesmosomal protein).

SUMMARY OF THE INVENTION

[0027] In the investigation of the molecular structure/activity relationships by an in vitro test of corneodesmosomal degradation, it has now surprisingly and unexpectedly been found that aminosulfonic acid compounds are capable of stimulating the degradation of corneodesmosine, undoubtedly by promoting the activity of proteases (of chymotrypsin-like and trypsin-like type in particular) involved in this process.

[0028] These aminosulfonic derivatives thus constitute excellent active agents for promoting the desquamation of the skin and/or for stimulating epidermal renewal and/or for combating aging of the skin.

[0029] Thus, the present invention features novel compositions comprising at least one derivative of aminosulfonic type, to promote the desquamation of the skin and/or to stimulate epidermal renewal and/or to combat intrinsic and/or extrinsic aging of the skin.

[0030] In addition, many skin pathologies are characterized by the production of a thickened horny layer and by abnormal desquamation, i.e., hyperkeratosis. This may occur on any anatomical area of skin and in very varied clinical contexts. Its physiopathological substratum and its cause are varied.

[0031] Examples that may be mentioned include:

[0032] xerosis (or dryness of the skin),

[0033] ichthyosis,

[0034] psoriasis,

[0035] certain benign or malignant tumoral lesions,

[0036] reactional hyperkeratoses.

[0037] Thus, the derivatives of aminosulfonic type according to the invention are capable of stimulating the degradation of corneodesmosine and thus constitute excellent active agents for promoting desquamation of the skin and/or for stimulating epidermal renewal and thus for treating skin pathologies characterized by the production of a thickened horny layer and by abnormal desquamation.

[0038] This invention thus features formulating at least one aminosulfonic acid compound corresponding to formula (I) below: 2

[0039] in which,

[0040] R denotes a hydrogen atom or a group chosen from —OH and —NH2,

[0041] X denotes:

[0042] an oxygen atom,

[0043] a group 3

[0044] a group 4

[0045] n is equal to 0, 1, 2 or 3,

[0046] into a cosmetic composition comprising a physiologically acceptable medium, as an agent for promoting the desquamation of the skin and/or for stimulating epidermal renewal and/or for combating intrinsic and/or extrinsic aging of the skin.

[0047] This invention also relates to the optical and/or geometrical isomers of the derivatives of formula (I), alone or as a mixture in all proportions, and also to the physiologically acceptable salts of these derivatives.

[0048] The expression “physiologically acceptable medium” means a medium which is compatible with the skin, mucous membranes, the nails, the scalp and the hair.

[0049] In the prior art publications, the aminosulfonic derivatives of formula (I) are known essentially as organic buffers. These buffers are used in biochemical tests and are known for their ability to preserve enzymatic activities. In addition, some of these buffers facilitate the survival of cultured cells. These “biological” buffers are sold by companies such as Sigma, Aldrich or Fluka.

[0050] To date, however, the use of aminosulfonic derivatives of formula (I) for promoting the desquamation of the skin and/or for stimulating epidermal renewal and thus for combating intrinsic and/or extrinsic aging of the skin has never been described in the prior art.

[0051] The present invention also features the use of a cosmetic composition comprising, in a physiologically acceptable medium, at least one aminosulfonic derivative of formula (I) as defined above, in a regime or regimen to promote the desquamation of the skin and/or to stimulate epidermal renewal and/or to combat intrinsic and/or extrinsic aging of the skin.

[0052] This invention also features the use of at least one aminosulfonic derivative of formula (I) as defined above, for the manufacture of a pharmaceutical or dermatological composition comprising a physiologically acceptable medium, the said composition being intended for promoting the desquamation of the skin and/or for stimulating epidermal renewal and/or for combating intrinsic and/or extrinsic aging of the skin.

[0053] This invention also features administration of at least one aminosulfonic derivative of formula (I) as defined above, to an individual in need of such treatment in a pharmaceutical or dermatological composition comprising a physiologically acceptable medium, the said composition being intended to treat skin pathologies characterized by the production of a thickened horny layer and by abnormal desquamation, particularly xerosis or dryness of the skin, ichthyosis, psoriasis, benign or malignant tumoral lesions, and reactional hyperkeratoses.

DETAILED DESCRIPTION OF BEST MODE AND SPECIFIC/PREFERRED EMBODIMENTS OF THE INVENTION

[0054] Needless to say, according to the invention, the aminosulfonic derivatives of formula (I) may be used alone or as a mixture in any proportion.

[0055] In the text hereinbelow, the term “aminosulfonic derivative of formula (I)” is understood as denoting the derivatives described above, of natural or synthetic origin, totally or partially purified, or any preparation containing them.

[0056] The expression “natural origin” means a derivative extracted from natural material in which it is present. The expression “synthetic origin” means a derivative prepared by chemical synthesis or by biotechnology.

[0057] The expression “totally or partially purified” means herein that, during its synthesis or compared with its natural state (fresh or dried plant or cells), the aminosulfonic derivative of formula (I), in the composition of the invention, has been concentrated and/or freed, respectively, of at least some of the reaction side products derived from its synthesis or of at least some of the other constituents of the plant.

[0058] Advantageously, the aminosulfonic acid compounds of formula (I) that are administered according to the invention are those for which

[0059] R denotes a hydrogen atom or an —OH group,

[0060] X denotes:

[0061] an oxygen atom,

[0062] a group 5

[0063] a group 6

[0064] n is equal to 0 or 1.

[0065] Among the derivatives of formula (I) that are preferentially administered according to the invention, mention may be made of:

[0066] 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid which corresponds to the following formula: 7

[0067] 4-(2-hydroxyethyl)piperazine-1-(2-hydroxypropane-sulfonic acid) which corresponds to the following formula: 8

[0068] 4-(2-hydroxyethyl)piperazine-1-propanesulfonic acid which corresponds to the following formula: 9

[0069] 3-morpholinopropanesulfonic acid which corresponds to the following formula: 10

[0070] 2-morpholinoethanesulfonic acid which corresponds to the following formula: 11

[0071] piperazine-1,4-bis(2-ethanesulfonic acid) which corresponds to the following formula: 12

[0072] piperazine-1,4-bis(2-hydroxypropanesulfonic acid) which corresponds to the following formula: 13

[0073] Among these derivatives, ones most particularly preferred are:

[0074] piperazine-1,4-bis(2-hydroxypropanesulfonic acid),

[0075] piperazine-1,4-bis(2-ethanesulfonic acid),

[0076] 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid.

[0077] The amount of aminosulfonic derivative of formula (I) which may be used according to the invention obviously depends on the desired effect and should be an amount which is effective for promoting the desquamation of the skin and/or for stimulating epidermal renewal and thus for combating intrinsic aging of the skin.

[0078] By way of example, the amount of aminosulfonic derivative of formula (I) which may be used according to the invention may range, for example, from 0.01% to 50% and preferably from 0.1% to 10% of the total weight of the composition.

[0079] The dermatological or pharmaceutical composition which may be used according to the invention may be ingested, injected or applied to the skin (to any area of body skin), the hair, the nails or mucous membranes (oral, jugal, gingival, genital or conjunctival membranes).

[0080] Depending on the mode of administration, the composition according to the invention may be in any pharmaceutical form normally used, particularly in cosmetology.

[0081] One preferred composition of the invention is a cosmetic composition intended for topical application.

[0082] For a topical application to the skin, the composition which may be used according to the invention may especially be in the form of an aqueous or oily solution or of a dispersion of the lotion or serum type, of emulsions of liquid or semi-liquid consistency of the milk type, obtained by dispersing a fatty phase in an aqueous phase (O/W emulsion) or conversely (W/O emulsion), or of suspensions or emulsions of soft consistency of the aqueous or anhydrous cream or gel type, or alternatively of microcapsules or microparticles, or of vesicular dispersions of ionic and/or nonionic type. These compositions are prepared according to the usual methods.

[0083] The composition which may be used according to the invention may also be a haircare composition, and especially a shampoo, a setting lotion, a treating lotion, a styling cream or gel, a dye composition (especially for oxidation dyeing) optionally in the form of coloring shampoos, restructuring lotions for the hair, a permanent-waving composition (especially a composition for the first stage of a permanent-waving operation), a lotion or gel for preventing hair loss, an antiparasitic shampoo, etc.

[0084] The amounts of the various constituents of the compositions which may be used according to the invention are those that are conventionally used in the fields under consideration.

[0085] These compositions especially constitute cleansing, protective, treating or care creams for the face, for the hands, for the feet, for the major anatomical folds or for the body (for example day creams, night creams, make-up-removing creams, foundation creams and antisun creams), fluid foundations, make-up-removing milks, protective body milks or bodycare milks, after-sun milks, skin care lotions, gels or mousses, for instance cleansing lotions, antisun lotions, artificial tanning lotions, bath compositions, deodorant compositions comprising a bactericidal agent, aftershave gels or lotions, hair-removing creams, insect-repellent compositions, pain-relief compositions, compositions for treating certain skin diseases, for instance eczema, acne rosacea, psoriasis, lichens and severe pruritus.

[0086] The compositions which may be used according to the invention may also consist of solid preparations constituting cleansing soaps or bars.

[0087] The compositions which may be used according to the invention may also be packaged in the form of an aerosol composition also comprising a pressurized propellant.

[0088] When the composition which may be used according to the invention is an emulsion, the proportion of the fatty phase may range from 5% to 80% by weight and preferably from 5% to 50% by weight relative to the total weight of the composition. The oils, waxes, emulsifiers and co-emulsifiers used in the composition in emulsion form are chosen from those conventionally used in cosmetics. The emulsifier and co-emulsifier are present in the composition in a proportion ranging from 0.3% to 30% by weight and preferably from 0.5% to 20% by weight relative to the total weight of the composition. The emulsion may also contain lipid vesicles.

[0089] When the composition which may be used according to the invention is an oily solution or gel, the fatty phase may represent more than 90% of the total weight of the composition.

[0090] In a known manner, the cosmetic composition may also contain adjuvants that are common in cosmetics, such as hydrophilic or lipophilic gelling agents, hydrophilic or lipophilic additives, preserving agents, antioxidants, solvents, fragrances, fillers, screening agents, odor absorbers and dyestuffs. The amounts of these various adjuvants are those conventionally used in cosmetics and, for example, from 0.01% to 10% of the total weight of the composition. Depending on their nature, these adjuvants may be introduced into the fatty phase, into the aqueous phase and/or into the lipid spherules.

[0091] As oils or waxes which may be used in the invention, mention may be made of mineral oils (liquid petroleum jelly), plant oils (liquid fraction of karite butter or sunflower oil), animal oils (perhydrosqualene), synthetic oils (purcellin oil), silicone oils or waxes (cyclomethicone) and fluoro oils (perfluoropolyethers), beeswax, carnauba wax or paraffin wax. Fatty alcohols and fatty acids (stearic acid) may be added to these oils. As emulsifiers which may be used in the invention, mention may be made, for example, of glyceryl stearate, polysorbate 60 and the mixture of PEG-6/PEG-32/glycol stearate sold under the name Tefose® 63 by the company Gattefosse.

[0092] As solvents which may be used in the invention, mention may be made of lower alcohols, especially ethanol and isopropanol, and propylene glycol.

[0093] As hydrophilic gelling agents which may be used in the invention, mention may be made of carboxyvinyl polymers (carbomer), acrylic copolymers such as acrylate/alkyl acrylate copolymers, polyacrylamides, polysaccharides such as hydroxypropylcellulose, natural gums and clays, and, as lipophilic gelling agents, mention may be made of modified clays, for instance bentones, metal salts of fatty acids, for instance aluminum stearates, and hydrophobic silica, ethylcellulose and polyethylene.

[0094] The compositions which may be used according to the invention may contain other hydrophilic active agents, for instance proteins or protein hydrolysates, amino acids, polyols, urea, allantoin, sugars and sugar derivatives, water-soluble vitamins, plant extracts and hydroxy acids.

[0095] Lipophilic active agents which may be used include retinol (vitamin A) and its derivatives, tocopherol (vitamin E) and its derivatives, essential fatty acids, ceramides, essential oils and salicylic acid and its derivatives.

[0096] The compositions which may be used according to the invention may combine at least one aminosulfonic derivative of formula (I) with other active agents. Among these active agents which may be mentioned, for example, are:

[0097] agents for modifying skin differentiation and/or proliferation, such as retinoic acid and its isomers, retinol and its esters, vitamin D and its derivatives, oestrogens such as oestradiol, kojic acid or hydroquinone;

[0098] depigmenting agents such as kojic acid or hydroquinone;

[0099] antibacterial agents such as clindamycin phosphate or erythromycin or antibiotics of the tetracycline family;

[0100] antiparasitic agents, in particular metronidazole, crotamiton or pyrethroids;

[0101] antifungal agents, in particular compounds belonging to the imidazole family, such as econazole, ketoconazole or miconazole or their salts, polyene compounds, such as amphotericin B, compounds of the allylamine family, such as terbinafine, or alternatively octopirox;

[0102] antiviral agents such as acyclovir;

[0103] steroidal anti-inflammatory agents, such as hydrocortisone, betamethasone valerate or clobetasol propionate, or non-steroidal anti-inflammatory agents such as, for example, ibuprofen and its salts, diclofenac and its salts, acetylsalicylic acid, acetaminophen or glycyrrhizic acid;

[0104] anaesthetics such as lidocaine hydrochloride and its derivatives;

[0105] anti-pruriginous agents, for instance thenaldine, trimeprazine or cyproheptadine;

[0106] agents acting on the radiance of the complexion by promoting turnover and desquamation (keratolytic agents), such as α- and β-hydroxycarboxylic acids or β-keto carboxylic acids, their salts, amides or esters and more particularly hydroxy acids such as glycolic acid, lactic acid, salicylic acid, citric acid and fruit acids in general, and 5-n-octanoylsalicylic acid;

[0107] free-radical scavengers, such as α-tocopherol or its esters, superoxide dismutases, certain metal chelating agents or ascorbic acid and its esters;

[0108] antiseborrhoeic agents such as progesterone;

[0109] antidandruff agents, for instance octopirox or zinc pyrithione;

[0110] antiacne agents, for instance, retinoic acid or benzoyl peroxide.

[0111] Other compounds may also be added to the above list, namely, for example Diazoxide, Spiroxazone, phospholipids, for instance lecithin, linoleic acid, linolenic acid, salicylic acid and its derivatives described in FR-2,581,542, for instance salicylic acid derivatives bearing an alkanoyl radical containing from 2 to 12 carbon atoms in position of the benzene ring, hydroxycarboxylic acids or keto carboxylic acids and their esters, lactones and their corresponding salts, anthralin, carotenoids, eicosatetraenoic acid and eicosatrienoic acid or their esters and amides.

[0112] Thus, according to one particular embodiment, the composition according to the invention also comprises at least one agent chosen from antibacterial agents, antiparasitic agents, antifungal agents, antiviral agents, anti-inflammatory agents, anti-pruriginous agents, anaesthetics, keratolytic agents, free-radical scavengers, antiseborrhoeic agents, antidandruff agents, antiacne agents and/or agents for modifying skin differentiation and/or proliferation, and extracts of plant, marine or bacterial origin, or mixtures thereof.

[0113] It may also be envisaged that the composition used according to the invention comprising at least one derivative of formula (I) as defined above is in liposomal form, as described especially in WO 94/22468 filed on Oct. 13, 1994 by Anti Cancer Inc.

[0114] FR-2,782,922 discloses a composition containing urea and an N-substituted aminosulfonic acid chosen from:

[0115] N,N-bis[2-hydroxyethyl]-2-aminoethanesulfonic acid;

[0116] N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid;

[0117] 3-[N-morpholino]propanesulfonic acid;

[0118] piperazine-N,N′-bis[2-ethanesulfonic acid];

[0119] 2-[N-morpholino]ethanesulfonic acid; and the use of this composition for caring for, treating and/or protecting human skin, mucous membranes and/or keratin fibers, and especially for moisturizing the skin and treating dry skin.

[0120] The N-substituted aminosulfonic acids are described in FR-2,782,922 as stabilizers for the urea in the composition.

[0121] In addition, WO 96/23490 discloses compositions especially containing N-2-hydroxyethyl-piperazine-N′-2-ethanesulfonic acid as an anti-irritant agent combined with anti-irritant components chosen from α- and β-hydroxycarboxylic acids, lactic acid and its salts and/or combined with urea as a second anti-irritant agent. WO 96/23490 discloses the use of the said compositions for reducing skin irritation in animals.

[0122] Thus, according to another aspect, a subject of the invention is a composition comprising at least a combination of at least one aminosulfonic derivative of formula (I) and of at least one pro-desquamating agent, with the exception of:

[0123] a composition containing urea and at least one N-substituted aminosulfonic acid chosen from N,N-bis[2-hydroxyethyl]-2-aminoethanesulfonic acid; N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid; 3-[N-morpholino]-propanesulfonic acid; piperazine-N,N′-bis[2-ethanesulfonic acid]; 2[N-morpholino]-ethanesulfonic acid;

[0124] a composition containing N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid and an ingredient chosen from α- and β-hydroxycarboxylic acids, lactic acid and its salts, and urea.

[0125] The other pro-desquamating agents are pro-desquamating agents that are known for their moisturizing properties and/or for their properties on the radiance of the complexion by promoting the turnover and desquamation (keratolytic agents).

[0126] The other pro-desquamating agents known for their moisturizing properties are chosen from glycerol and urea and derivatives thereof, pyrrolidonecarboxylic acid, and ammonium salts of lactic acid.

[0127] The other pro-desquamating agents acting on the radiance of the complexion by promoting turnover and desquamation (keratolytic agents) are chosen from hydroxy acids, in particular α- and β-hydroxycarboxylic acids or β-keto carboxylic acids, and their salts, amides or esters, and more particularly glycolic acid, lactic acid, salicylic acid, citric acid and fruit acids in general, and 5-n-octanoylsalicylic acid.

[0128] One embodiment of the invention thus features a non-therapeutic regime or regimen for treating the skin which is intended for promoting desquamation of the skin and/or for stimulating epidermal renewal, wherein a cosmetic composition comprising at least one aminosulfonic derivative of formula (I) as defined above is topically applied to the skin.

[0129] Yet another embodiment of the invention is a non-therapeutic treatment process for combating intrinsic and/or extrinsic aging of the skin, wherein a cosmetic composition comprising at least one aminosulfonic derivative of formula (I) as defined above is applied to the skin.

[0130] This invention also features a regime or regimen for promoting desquamation of the skin and/or for stimulating epidermal renewal and thus for combating aging of the skin in an individual displaying abnormally low skin desquamation and/or abnormally low epidermal renewal, comprising the topical application to the skin of an effective amount of at least one aminosulfonic derivative of formula (I) as defined above.

[0131] This invention also features a regime or regimen for promoting desquamation of the skin and/or for stimulating epidermal renewal in an individual displaying a production of thickened horny layer and/or abnormal desquamation, comprising the topical application to the skin of an effective amount of at least one aminosulfonic derivative of formula (I) as defined above.

[0132] In order to further illustrate the present invention and the advantages thereof, the following specific examples are given, it being understood that same are intended only as illustrative and in nowise limitative.

[0133] In said examples to follow, all parts and percentages are given by weight, unless otherwise indicated.

EXAMPLE 1

[0134] Method for evaluating desquamation by measuring the degradation of corneodesmosines

[0135] The ability of aminosulfonic derivatives of formula (I) according to the invention to promote desquamation by degradation of corneodesmosines is studied in this example.

[0136] Corneodesmosine is one of the major markers of desquamation of the corneodesmosome. It is studied by immunoblotting after separation by electrophoresis and transfer onto a membrane. After a specific labeling with monoclonal antibody G36-19, it is revealed by chemiluminescence.

[0137] The mouse monoclonal antibody G36-19 is specific for corneodesmosine; it forms part of a series of antibodies directed against epidermal differentiation antigens, produced after immunizing a mouse with a homogenate of human plantar horny layer, and then characterized (Serre G. et al., J. Invest. Dermatol. 1991; 97(6): 1061-72).

[0138] Varnish-stripping operations are carried out on the lower legs of volunteers (modification of the procedure by Lundström A. and Egelrud T., Acta Derm. Venereol. (Stockholm) 71, 471-474, 1991). The nylon-varnish strips associated with the corneocytes are immersed in 1 ml/cm2 of acetone in order to detach the corneocytes. The mixture is filtered and then rinsed three times with the same volume of acetone in order to remove all trace of varnish. Finally, the mixture is dried under vacuum: acetonic powders of stratum corneum are thus obtained.

[0139] The acetonic powders are divided into 1 mg aliquots. 100 μl of the aqueous solutions containing 2% of active agent adjusted to pH 8.0 are added. Controls without active agent are prepared under the same conditions. Two incubation times are studied: t=0 and t=17 h. In the latter case, the incubation takes place at 30° C. with stirring.

[0140] After incubation, the mixtures are centrifuged for 10 minutes at 10 000×g. The supernatant is removed and replaced with 100 μl of 0.0625 M Tris/HCl pH 6.8 Laemmli buffer, 2% SDS, 200 mM DTT, 10% glycerol, which allows the proteins to be extracted. The mixture is boiled for 10 minutes at 100° C. and then ground in a Potter mill. The mixture is centrifuged for 10 minutes at 10 000×g and the supernatant is then collected. It contains the corneodesmosomal proteins.

[0141] The total proteins are assayed according to the Bradford method (Biorad kit). This allows an adjustment to 0.6 mg/ml of the samples and a real comparison of the treatments.

[0142] The samples and also a Rainbow (Amersham Pharmacia Biotech) low molecular weight standard at ⅓ are separated by electrophoresis on gel containing 12% acrylamide for 30 minutes at 100 V and then for 1 hour at 200 V. After the electrophoresis, the proteins are transferred onto an Immobilon-P membrane (Millipore) for 3 hours at 60 V. The membrane is then incubated for twice 15 minutes in TBS-TL buffer: 25 mM Tris, 0.15M NaCi pH 7.2, 0.05% Tween 20, 0.5% skimmed milk powder, in order to block the non-specific sites. Incubation with the antibody G36-19 at {fraction (1/12500)} is performed overnight at 4° C. After two rinses of 5 minutes in TBS-TL buffer, the membrane is incubated with a goat anti-mouse IG(H+L) antibody peroxidase conjugate (Biorad) at 1/4000 for 1 hour 30 minutes at ambient temperature. After several rinses of 5 minutes in TBS-TL buffer and then TBS buffer (without milk or Tween), the membrane is incubated for 1 minute in 10 ml of ECL reagent (Amersham Pharmacia Biotech). The chemiluminescence of the corneodesmosine bands is measured with the FluorS Multimager (Biorad). The 33 and 46 kD bands are quantified with the Quantity-one software (Biorad).

[0143] The results of this study are summarized in the table below.

[0144] Glycine is used as reference compound (positive control) in this study; EP-A2-0,852,949 (Shiseido) having shown that glycine promotes the degradation of desmoglein (corneodesmosomal protein).

TABLE
Effect of aminosulfonic derivatives of formula (I) on the degradation of
corneodesmosines compared with glycine (positive control)
                                 Percentage increase
                                 in the degradation
Test Molecules                   of corneodesmosine
Control                          0%
Piperazine-1,4-bis(2-hydroxy-    63%
propanesulfonic acid)
Piperazine-1,4-bis(2-ethane-sulfonic 65%
acid)
3-Morpholinopropanesulfonic acid 39%
4-(2-Hydroxyethyl)piperazine-1-  65%
ethanesulfonic acid
Glycine                          51%

[0145] The control corresponds to a control prepared with the dissolution buffer without active agent under the same conditions of the test. This control takes into account the natural degradation of the corneodesmosines which takes place during the incubation.

[0146] It emerges clearly that the aminosulfonic derivatives of formula (I) tested promote the degradation of corneodesmosines and that several are better than the glycine used as positive control in this test.

EXAMPLE 2

[0147] Compositions:

[0148] Pro-desquamating cream for the face:

	Piperazine-1,4-bis(2-hydroxypropane-	2.00%
	sulfonic acid)
	Sodium stearate		3.00%
	Liquid petroleum jelly		6.00%
	Alkylparaben		0.05%
	Potassium sorbate		10.00%
	Stearyl alcohol		1.00%
	Fragrance		1.00%
	Water	qs	100.00%

[0149] Pro-desquamating cream for the body:

	Piperazine-1,4-bis(2-ethanesulfonic	5.0%
	acid)
	Jojoba oil		13.0%
	Sipol wax		6.0%
	Isopropyl palmitate		2.0%
	Glycerol		15.0%
	Alkylparaben		0.5%
	Fragrance		1.0%
	Water	qs	100.0%

[0150] Pro-desquamating care cream:

	Piperazine-1,4-bis(2-ethanesulfonic acid)	1%
	Oxyethylenated polyethylene glycol 50		3%
	Mono-diglyceryl stearate		3%
	Liquid petroleum jelly		24%
	Cetyl alcohol		5%
	Water	qs	100%

[0151] Desquamating care cream for the body:

	4-(2-Hydroxyethyl)piperazine-1-	0.5%
	ethane-sulfonic acid
	Sipol wax		6.0%
	Glyceryl monostearate		1.5%
	Sodium stearate		0.8%
	Liquid petroleum jelly		6.0%
	Isopropyl palmitate		2.0%
	Glycerol		15.0%
	Fragrance		0.3%
	Water	qs	100.0%

[0152] Pro-desquamating care cream:

	4-(2-Hydroxyethyl)piperazine-1-ethane-	0.50%
	sulfonic acid
	Jojoba oil		13.00%
	Alkylparaben		0.05%
	Potassium sorbate		0%
	Cyclopentadimethylsiloxane		10.00%
	Stearyl alcohol		1.00%
	Stearic acid		4.00%
	Polyethylene glycol stearate		3.00%
	Vitamin E		1.00%
	Glycerol		3.00%
	Water	qs	100.00%

[0153] Each patent, patent application and literature article/report cited or indicated herein is hereby expressly incorporated by reference.

[0154] While the invention has been described in terms of various specific and preferred embodiments, the skilled artisan will appreciate that various modifications, substitutions, omissions, and changes may be made without departing from the spirit thereof. Accordingly, it is intended that the scope of the present invention be limited solely by the scope of the following claims, including equivalents thereof.

Claims

1. A regime or regimen for promoting desquamation of the skin and/or stimulating epidermal renewal and/or combating aging of the skin, comprising administering to an individual in need of such treatment, a thus effective amount of at least one aminosulfonic acid compound having the structural formula (I):

2. A regime or regimen for treating a skin pathology characterized by the production of a thickened horny layer and by abnormal desquamation, comprising administering to an individual in need of such treatment, a thus effective amount of at least one aminosulfonic acid compound having the structural formula (I):

3. The regime or regimen as defined by claim 2, comprising treating xerosis or dryness of the skin, ichthyosis, psoriasis, benign or malignant tumoral lesions, or reactional hyperkeratoses.

4. The regime or regimen as defined by claim 1, wherein formula (I), R is a hydrogen atom or an —OH group; X is an oxygen atom, a group:

5. The regime or regimen as defined by claim 1, said at least one aminosulfonic acid compound of formula (I) comprising 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid; 4-(2-hydroxyethyl)piperazine-1-(2-hydroxypropane-sulfonic acid); 4-(2-hydroxyethyl)piperazine-1-propanesulfonic acid; 3-morpholinopropanesulfonic acid; 2-morpholinoethanesulfonic acid; piperazine-1,4-bis(2-ethanesulfonic acid); or piperazine-1,4-bis(2-hydroxypropanesulfonic acid).

6. The regime or regimen as defined by claim 5, said at least one aminosulfonic acid compound of formula (I) comprising piperazine-1,4-bis(2-hydroxypropanesulfonic acid); piperazine-1,4-bis(2-ethanesulfonic acid); or 4-(2-hydroxyethyl)piperazine-1-ethanesulfonic acid.

7. The regime or regimen as defined by claim 1, comprising coadministering to said individual in need of such treatment, an effective amount of at least one active agent selected from the group consisting of antibacterial agents, antiparasitic agents, antifungal agents, antiviral agents, anti-inflammatory agents, anti-pruriginous agents, anaesthetics, agents affecting the radiance of the complexion by promoting turnover and desquamation, free-radical scavengers, antiseborrhoeic agents, antidandruff agents, antiacne agents and/or agents for modifying skin differentiation and/or proliferation, depigmenting agents, extracts of plant, marine or bacterial origin, and mixtures thereof.

8. The regime or regimen as defined by claim 1, comprising coadministering to said individual in need of such treatment, an effective amount of at least one other pro-desquamating agent other than a composition containing urea and at least one N-substituted aminosulfonic acid selected from among N,N-bis[2-hydroxyethyl]-2-aminoethanesulfonic acid; N-2-hydroxyethylpiperazine-N ′-2-ethanesulfonic acid; 3-[N-morpholino]propanesulfonic acid; piperazine-N, N′-bis[2-ethanesulfonic acid]; and 2-[N-morpholino]-ethanesulfonic acid; and other than a composition containing N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid, an α- or β-hydroxycarboxylic acid, lactic acid or salts thereof, and urea.

9. The regime or regimen as defined by claim 8, said at least one other pro-desquamating agent having moisturizing properties and/or affecting the radiance of the complexion.

10. The regime or regimen as defined by claim 9, said at least one other pro-desquamating agent having moisturizing properties and being selected from the group consisting of glycerol and urea and derivatives thereof, pyrrolidonecarboxylic acid, and the ammonium salts of lactic acid.

11. The regime or regimen as defined by claim 9, said at least one other pro-desquamating agent affecting the radiance of the complexion and comprising a hydroxy acid, or salt, amide or ester thereof.

12. The regime or regimen as defined by claim 11, said hydroxy acid, or salt, amide or ester thereof comprising an α- or β-hydroxycarboxylic acid, a β-keto carboxylic acid, or salt, amide or ester thereof.

13. The regime or regimen as defined by claim 12, said hydroxy acid comprising glycolic acid, lactic acid, salicylic acid, citric acid, a fruit acid or 5-n-octanoylsalicylic acid.

14. The regime or regimen as defined by claim 1, comprising topically applying said at least one aminosulfonic acid compound of formula (I) onto the skin of said individual in need of such treatment.

15. The regime or regimen as defined by claim 1, comprising administering 0.01% to 50% by weight of said at least one aminosulfonic acid compound formulated into said physiologically acceptable medium therefor.

16. The regime or regimen as defined by claim 1, comprising administering 0.1% to 10% by weight of said at least one aminosulfonic acid compound formulated into said physiologically acceptable medium therefor.

17. A cosmetic/therapeutic composition suited for promoting desquamation of the skin and/or stimulating epidermal renewal and/or combating skin aging, comprising (1) a thus effective amount of at least one aminosulfonic acid compound having the structural formula (I):

18. A cosmetic/therapeutic composition suited for promoting desquamation of the skin and/or stimulating epidermal renewal and/or combating skin aging, comprising (1) a thus effective amount of at least one aminosulfonic acid compound having the structural formula (I):

19. The cosmetic/therapeutic composition as defined by claim 17, formulated as an aqueous or oily solution, lotion, serum, emulsion, milk, suspension, cream, gel, microcapsules, microparticles, mousse, solid, aerosol, permanent wave, or shampoo.

20. The cosmetic/therapeutic composition as defined by claim 18, formulated as an aqueous or oily solution, lotion, serum, emulsion, milk, suspension, cream, gel, microcapsules, microparticles, mousse, solid, aerosol, permanent wave, or shampoo.