Use of salicylic acid derivatives as prodesquamating active agent

Abstract

Cosmetic use of at least one salicylic acid derivative of following formula (I) in which L represents a linear or branched hydrocarbon radical comprising from 1 to 12 carbon atoms and having or not having one or more ethylenic unsaturations, and X represents a radical chosen from —OH and —CO.sub.2H, and also its cosmetically acceptable salts, its solvates, such as its hydrates, and its isomers, in a composition comprising a physiologically acceptable medium, as cosmetic agent intended to promote the desquamation of the skin and/or to stimulate epidermal renewal. ##STR00001##

Claims

1. Cosmetic method comprising: identifying an individual in need of promotion of desquamation of the skin and/or stimulation of epidermal renewal due to influence of exogenous factors and/or endogenous factors, with the exclusion of UV radiation, applying to the individual's skin, as cosmetic agent, at least one salicylic acid derivative of following formula (I): ##STR00020## in which: L represents a saturated linear hydrocarbon radical comprising from 6 to 10 carbon atoms composed of carbon atoms and of hydrogen atoms, and X represents a radical chosen from —OH and —CO.sub.2H, or a salt, solvate, or isomer thereof, or a composition comprising the salicylic acid derivative of formula (I) or a salt, solvate, isomer, or mixture thereof, and promoting the desquamation of the skin and/or stimulating epidermal renewal.

2. Cosmetic method comprising: identifying an individual in need of improving the appearance and/or the texture of the skin due to influence of exogenous factors and/or endogenous factors, with the exclusion of UV radiation, applying to the individual's skin, as cosmetic agent, at least one salicylic acid derivative of following formula (I): ##STR00021## in which: L represents a saturated linear hydrocarbon radical comprising from 6 to 10 carbon atoms composed of carbon atoms and of hydrogen atoms, and X represents a radical chosen from —OH and —CO.sub.2H, or a salt, solvate, or isomer thereof, or a composition comprising the salicylic acid derivative of formula (I) or a salt, solvate, isomer, or mixture thereof, and improving the appearance and/or the texture of the skin.

3. Cosmetic method comprising: identifying an individual in need of at least one of combating imperfections of the skin, rendering uniform the relief of the skin, rendering uniform the complexion, closing the pores, removing bumps by providing a smoothing-out effect, reducing surface irregularities and the skin microrelief, improving the radiance of the complexion, improving the wear property of the make-up, and promoting the cleaning action and the removal of dead cells at the surface of the body or face due to influence of exogenous factors and/or endogenous factors, with the exclusion of UV radiation, applying to the individual's skin, as cosmetic agent, at least one salicylic acid derivative of following formula (I): ##STR00022## in which: L represents a saturated linear hydrocarbon radical comprising from 6 to 10 carbon atoms composed of carbon atoms and of hydrogen atoms, and X represents a radical chosen from —OH and —CO.sub.2H, or a salt, solvate, or isomer thereof, or a composition comprising the salicylic acid derivative of formula (I) or a salt, solvate, isomer, or mixture thereof, and combating imperfections of the skin, rendering uniform the relief of the skin, rendering uniform the complexion, closing the pores, removing bumps by providing a smoothing-out effect, reducing surface irregularities and the skin microrelief, improving the radiance of the complexion, improving the wear property of the make-up, and promoting the cleaning action and the removal of dead cells at the surface of the body or face.

4. Method according to claim 1, wherein said salicylic acid derivative is of natural or renewable origin.

5. Method according to claim 1, wherein said salicylic acid derivative is chosen from the following compounds A and B, their salts and/or solvates: ##STR00023##

6. Cosmetic treatment method comprising: identifying an individual in need of promoting the radiance of the complexion and/or decreasing the surface irregularities of the skin and/or mucous membranes due to influence of exogenous factors and/or endogenous factors, with the exclusion of UV radiation, applying to the individual's skin or mucous membranes at least one salicylic acid derivative of formula (I) ##STR00024## in which: L represents a saturated linear hydrocarbon radical comprising from 6 to 10 carbon atoms composed of carbon atoms and of hydrogen atoms, and X represents a radical chosen from —OH and —CO.sub.2H, or a salt, solvate, or isomer thereof, or a composition comprising the salicylic acid derivative of formula (I) or a salt, solvate, isomer, or mixture thereof, and promoting the radiance of the complexion and/or decreasing the surface irregularities of the skin and/or mucous membranes.

Description

EXAMPLES

Example 1

Synthesis of the Compound A

(1) ##STR00018##

(2) 2 g of mixture of anacardic acids prepared according to the method described in J. Agric. Food Chem., 2001, 49, 2548-2551, are ozonolysed in 50 ml of ethyl acetate at −78° C. for 2 hours. The reaction is monitored by thin layer chromatography until the anacardic acid has disappeared. After evaporation of the solvent, the mixture obtained is hydrogenated in the presence of 5% palladium-on-charcoal (0.24 g) in 50 ml of ethanol for 4 hours. The catalyst is filtered off through Celite and the filtrate is evaporated under reduced pressure. Purification by chromatography on silica gel (petroleum ether/ethyl acetate with ratios by volume from 20/1 to 5/1) makes it possible to obtain the intermediate aldehyde 1 (0.7 g). This intermediate is subsequently reduced by using 1.5 equivalents (100 mg) of sodium borohydride in 100 ml of methanol at ambient temperature for 2 hours in order to result, after washing operations with a 0.1M hydrochloric acid solution, extraction with 2*100 ml of ethyl acetate and evaporation of the solvent under reduced pressure, in 0.42 g of the compound A in the form of a white solid.

(3) The NMR spectrum and the elemental analysis confirm the structure of the expected compound.

Example 2

Synthesis of the Compound B

(4) ##STR00019##

(5) 2 g of mixture of anacardic acids prepared according to the method described in J. Agric. Food Chem., 2001, 49, 2548-2551, are ozonolysed in 50 ml of ethyl acetate at −78° C. for 2 hours. The reaction is monitored by thin layer chromatography until the anacardic acid has disappeared. After evaporation of the solvent, the mixture obtained is hydrogenated in the presence of 5% palladium-on-charcoal (0.24 g) in 50 ml of ethanol for 4 hours. The catalyst is filtered off through Celite and the filtrate is stirred in the air for 72 hours. The medium is then evaporated under reduced pressure and the residue is purified by chromatography on silica gel (petroleum ether/ethyl acetate with ratios by volume from 20/1 to 5/1) in order to result in 0.42 g of the compound B in the form of a white solid.

(6) The NMR spectrum and the elemental analysis confirm the structure of the expected compound.

Example 3

Evaluation of the Desquamating Activity of the Compounds A and B

(7) The study is targeted at detecting the desquamating potential of the active agents in simplex solution by observation of the cohesion of the stratum corneum.

(8) The keratolytic effect on excised skin maintained under survival conditions at 5% by weight in ethanol was evaluated. The study was carried out on viable human skin resulting from abdominal or breast reduction plastic surgery (6 donors).

(9) The protocol consists in applying the test solutions to skin samples maintained under survival conditions. The products tested are applied in a proportion of 15 μl per 1 cm.sup.2 sample and are not rinsed off. Application is carried out twice, at D0 and then, 24 hours later, at D1. The morphology of the stratum corneum is analysed 48 hours after the first application, at D2, on a biopsy.

(10) The solutions applied are the following: compound A of Example 1, at 5% by weight in ethanol, and compound B of Example 2, at 5% by weight in ethanol.

(11) By way of comparison, no solution is applied to some samples, referred to as controls.

(12) The histological analysis of the horny layer is carried out on a skin section after staining with hemalaun-eosin (magnification 400). The decrease in the cohesion of the stratum corneum is expressed in the form of a score: score 0: absence of modification score 1: slight decrease score 2: moderate decrease score 3: large decrease score 4: very large decrease with exfoliation

(13) The results obtained appear in the following table. 6 samples were used for each of the tests (control, compound A and compound B). A paired Student test (p<0.05) was carried out in order to evaluate the significance of the difference with respect to the control.

(14) TABLE-US-00001 Score Product (mean ± sd, n = 6) Statistic None (control) 1.20 ± 0.2 / EtOH 0.98 ± 0.4 / Compound A at 5% in EtOH 1.85 ± 0.4 *p = 0.008 Compound B at 5% in EtOH 1.75 ± 0.2 *p = 0.01  *p: significant difference with respect to the untreated skin control (paired Student, p < 0.05)

(15) Thus, the compounds A and B at 5% really do bring about a decrease in the cohesion of the stratum corneum. This decrease is statistically significant with respect to the control skin and illustrates a desquamating effect at this concentration.

(16) In order to validate the desquamating properties of the compounds A and B and to evaluate the tolerance of the skin to these treatments, the morphology of a control skin was in addition compared with the morphology of the skin samples treated with A and with B present in a content of 5% by weight in ethanol, according to the protocol described above.

(17) The appearance of the stratum corneum was studied in order to evaluate the desquamating properties of A and B and the morphology of the epidermis was observed in order to determine the tolerance of the skin with respect to these compounds.

(18) A decrease in the cohesion of the stratum corneum and also the preservation of the morphology of the epidermis were observed, which clearly illustrates the desquamating property of the compounds A and B in combination with good tolerance of the skin.

Example 4

Composition Examples

(19) The three compositions which follow for topical application to the face are prepared.

(20) TABLE-US-00002 Composition 1: Components Amount as percentage by weight Carbomer 0.3 Preservatives q.s. Compound A 0.1 Water q.s. for 100

(21) TABLE-US-00003 Composition 2: Components Amount as percentage by weight Carbomer 0.3 Preservatives q.s. Compound B 1   Water q.s. for 100

(22) TABLE-US-00004 Composition 3: Components Amount as percentage by weight Carbomer 0.3 Preservatives q.s. Compound B 5   Water q.s. for 100

(23) These compositions can be applied to the face daily or at the rate of once weekly, according to the effect desired.