FR2824475A1 - New topical composition containing silanol and alpha hydroxy acids to enhance its antiaging effects, is useful for preventing symptoms of skin aging - Google Patents

Abstract

The invention is based on the discovery that the presence of alpha hydroxy acids, their salts or esters increases and stimulates the antiaging effects of silanol or its derivatives. Topical composition for preventing symptoms of aging comprising a combination of at least one alpha hydroxy acid (I) or one of its salts and at least one silanol (II), is new.

Description

the skin.

  The present invention relates to a new composition

  cosmetic, and more particularly a composition comprising

  nant in combination with a silanol and an alpha-hydroxy acid or a salt or ester of alpha-hydroxy acid, usable by topical application for the protection of the skin and the prevention of skin conditions, in particular the prevention of

  symptoms related to aging.

  The skin consists of three parts, the epidermis, the dermis and the hypodermis, each of which has specific properties making this set a real reacting and adapting organ.

  to the conditions of its environment.

  The particularity of the hand is that it presents two very distinct zones: the palm and the top of the hand. At the palm level, the skin is thick and resistant. The epidermis present

  1S hyperkeratinization, and the hypodermis includes

  fatty sinets. The palm is therefore relatively resistant to

external aggressions.

  On the other hand, at the level of the top of the hand, the aegis is fine and fragile. In addition, the hypodermis contains little adipose tissue. The skin of this area, on the other hand, has great flexibility, so that it can be stretched during movements of the hand and fingers. It is often used and is exposed almost chronically to the aggressions of the sun. This skin is therefore subjected to a

accelerated aging.

  Finally, in the case of skins with a clear phototype, the sensitivity to the aggressions of the sun is further increased. We also observe an accelerated aging of these

fair skin.

  Furthermore, it is known that, in order to be accepted by users, the cosmetic and! Or dermato logical compositions intended for the treatment and prevention of skin conditions by topical application must be pleasant to use and present 'of good physical properties, especially consistency and smoothness, while

  guaranteeing satisfactory efficiency.

  However, it is difficult to reconcile the effectiveness and practicality of applying a composition intended for the prevention and / or correction of the dermatological conditions considered. In the state of the art, the teaching of document FR-A-2.7 61.607 discloses in particular a dermatological composition for the treatment of the symptoms of aging of the skin. This composition comprises at least o a derivative of methylated silanol and at least one derivative of a hydrolysed vegetable protein. In another embodiment, this composition also comprises a vitamin C derivative. Silanol is part of the family of organic silicon derivatives. It is known for uses in the dermatological and cosmetic fields for a topical application in order to fight against aging.

  skin. It has a known effect of stimulating recognition

  truction of the dermo-epidermal barrier. In particular, it stimulates the synthesis of collagen and elastin in

dermis cells.

  Various cosmetic compositions propose the use of silanols or silanol derivatives, for example in combination with mannuronic or hyaluronic acids as in patent FR-A-2,611,496, or with a polysaccharide as in patent FR-A-2,667 .240, or in the form of a condensation product with an amino acid such as serine, as in patent EP-A-295,983. According to patent FR-A-2. 761.607 cited above, the proposed combination of methyl silanol and hydrolyzed vegetable protein is co-ordinated to prevent the formation of cross links between the proteins of the connective tissue of the skin, in particular between the collagen proteins. These cross-links result in the long term in a stiffening of the tissue and a loss of elasticity of the skin. In the variant where the composition comprises vitamin C, this stimulates the synechesis of neccollagen, and maintains a degree of glycosylation of the collagen synthesized

  to protect it from the formation of these cross links.

  It thus inhibits the production of free radicals.

  The compositions of the prior art pose a problem because the activity of the silanol incorporated in these compositions is low. Indeed, the effects observed are more linked to the presence of an intake of fibers than to a real

  stimulation of cells linked to silanol.

  Now, the Applicant has discovered that the presence of alpha hydroxy acids, or of alpha hydroxy acid salts or esters, in cosmetic compositions provides an increase and a stimulation of the effects provided by silanol, or the

silanol derivatives.

  The subject of the invention is therefore a composition for protecting the skin containing at least one alpha-hydroxy acid or one of its salts or esters, in combination with at least

minus one silanol.

  More particularly, the present invention relates to a cosmetic composition, administrable by topical route, having excellent qualities of use and making it possible to strengthen the protection of the skin against external aggressions and to promote the repair process of

various skin conditions.

  A subject of the invention is also a method of cosmetic treatment of the skin intended for the prevention of symptoms linked to aging of the skin, by local application of a composition based on silanols and alpha-hydroxy acids on the skin and in particular on the skin area the

more exposed.

  In particular, silanol increases the number of fibroblasts present in the layers of the dermis and of the epidermis, by simultaneously increasing the synthesis of collagen by these

  fibroblasts. The dermis is then denser and more resistant.

  The silanol used in the compositions of the invention is of s

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  preferably an alkyl silanol, and more particularly a methyl silanol. Preferably, the alpha-hydroxy acid is chosen from citric acid, lactic acid, mandelic acid and glycolic acid, or their salts or esters, alone or in combination. In a preferred embodiment, the composition comprises a proportion of alpha-hydroxy acid and of alpha-hydroxy acid derivatives of between 5% and 30% by weight relative to the total weight of the composition. In a particular embodiment, the alpha-hydroxy acid is present in the form of one of its salts or esters. These salts and esters can be used individually or as a mixture with one another or with alpha-hydroxy acids. In this case, preferably the alpha hydroxy acid salt represents between 3 and 15% by weight of the composition, and more preferably between 5 and 10%, and the alpha hydroxy acid ester represents between 3 and 15 % by weight of the composition, and more preferably between 5 and%. Alpha-hydroxy acids such as lactic acid, glycolic acid, mandelic acid or citric acid facilitate the exfoliation of cells on the surface of the epidermis. In the examples described below, the alpha-hydroxy acid chosen is citric acid. This alpha-hydroxy acid very significantly improves the scaling, oxygenation and hydration mechanisms of cells. Moreover, he

  stimulates the synthesis of glycoaminoglycans.

  To optimize the tolerance vis-à-vis the presence of alpha-hydroxy acid in the composition, according to a method of

  perfected realization, the composition includes galac-o-

  arabinan (Laracare A2002) and or a prepolymer polyal. They have a film-forming power which makes it possible in particular to adjust the water losses, while giving a soft and satin appearance to the composition. In addition to alpha-hydroxy acid, a composition according to this preferred embodiment comprises a proportion of methylated silanol, or of a derivative of methylated silanol, of between 1% and 20% by weight relative to the total weight of the composition, and more preferably between 3 and 7%, for example around 5%. Several compounds can be used as silanol derivatives, and for example mono-alkyl silane triols and dialkyl silane diols o the alkyl group can 0 comprise a straight chain or branching from 1 to 12 carbon atoms, and constitute for example a methyl, ethyl, propyl, isopropyl or butyl group. Among the most commonly used silanol derivatives, and more particularly methyl silanol, there may be mentioned, inter alia, methylsilanol sodium mannuronate (Algisiumê), methylsilanol mannuronate (Algisium C), dimethylsilanol hyaluronate (DSHC @), dimethylsilanol sodium hyaluronate (DSHô), methylsilanol sodium lactate (Lasiliumê), ascorbyl-methylsilanol (concentrated Ascorbosilane C), methylsilanol glycyrrhizinate (Glysinolô), hydroxyproline

  methylilanol (Hydroxyprolisilane), hydroxypro- aspartate

  line methylsilanol (Hydroxyprolisilane Cô, acetylmethionate

  methylsilanol (Methiosilane), acetylmethio- elastinate

  nylmethylsilanol (Methiosilane Cô), the cocost of methyl 2s silanol-PEG-7glyceryl (Monosiliolô), and the acetyltyrosinate of methylsilanol (Tyrosilane). All of these silanol derivatives are commercially available, and are produced in particular

by the company Exsymol.

  Among the methyl silanol derivatives claimed in the context of the present invention, there may be mentioned more particularly methylsilanol mannuronate, ascorbyl methylsilanol, hydroxyproline methylsilanol, and hydroxyproline aspartate methylailanol. Preferably, in the compositions of the invention, hydroxyproline aspartate is used.

  methylsilanol (Hydroxyprolisilane C, Exsymol).

  To improve the action of the composition once absorbed by the upper layers of the skin, the composition comprises vitamin C, preferably in the form of a salt or an ester derived from ascorbic acid. Vitamin C, in combination with alpha-hydroxy acids, has the advantage of exerting an anti-radical action and gentle exfoliation accompanied by keratorequlation,

  while, associated with silanols, it promotes the restoration

  ration of the dermo-epidermal union and the synchesis of

glycosaminoglycans.

  The concentrations of vitamin C or one of its derivatives can generally vary from 0.1 to 5% by weight, the preferred concentrations usually being between O, S

  and 2% by weight relative to the total weight of the composition.

  Vitamin C, or one of its derivatives (for example, ascorbyl tetra-isopalmitate or tetra hexyl decyl ascorbate) included in the composition of the invention, can further improve the anti-aging treatment process , because it controls the disorders of the pigmentaion, and it limits the atrophy of the dermis and the epidermis while supporting, it, too, the synChèse of collagen. In addition, vitamin C

  provides the skin with an anti-free radical system.

  Stable derivatives of vitamin C can be chosen from the salts or ascorbyl esters thus cue the encapsulated 2s forms of vitamin C: magnesium ascorbate (Vitacedone @, UCIB), ascorbyl and magnesium phosphate (Nikkal VC -PMG3, Jan Dekker), ascorbyl palmitate, ascorbylmethylsilanol pectinate (AscorUilane C, Exsymol, ascorbic acid polypeptide (Vitazyme C, Brocks). O- can also use microspheres whose walls are l-carrageenan encapsulating vitamin C (Lipotec $) or microspheres whose wall is atelocollagen encapsu2an ascorbyl phosphate and magnesium (Thallaspheres from the company Coletica) In addition to stimulating the production of collagen, a composition according to The invention may advantageously contain degigmenting agents, in fact one of the symptoms of aging is the appearance of spots, generally of brownish color, on the top of the hands as well as on the forearms, and the ha ut of the shoulders. These depigmenting agents

  and lightening masks these tasks.

  The composition according to the invention comprises for example glabridin. Glabridin is known to inhibit the production of melanin by the cells of the dermis, blocking an enzyme, mainly tyrosinase, used in the synthesis of melanin. In addition to glabridin, the depigmenting agents can be chosen from the extract soluble in licorice oil, licorice extract, licochalone extract. Other depigmentants can also be used in the composition according to the invention, for example a derivative

  ascorUic acid such as ascorbyl tetraisopalmitate.

  In such a composition, the alpha hydroxy acids

  reinforce the action of these degigmenting agents.

  The composition according to the present invention may also contain various adjuvants and excipients commonly used in the techniques of cosmetic and dermatological compositions. It can for example contain preservatives, thickeners, hydrophilic or lipophilic gelling agents, emulsifying agents, humectants, antioxidants, hydrating agents, surfactants, perfumes, and various additives intended for

  improve the physical properties of the composition.

  3c The gelling agents or thickeners may for example be - chosen from acrylate copolymers, for example polymethyl methacrylate, or natural gomes, for example a xanthan gem. A component such as perfluerodecaline can be advantageously incorporated for

  improve the smoothness of such a composition.

  The moisturizing or moisturizing agent can be chosen from a polyol, sorbitol, maltitol, pentaerythritol, glycerin, glycol, propylene glycol, polyethylene glycol, phenoxyethanol, polyacrylates and polymetha crylates of glyceryl, glycerol or glycerol derivatives. In general, any moisturizing agent suitable for cosmetic or dermatological compositions can be used

  in the present invention. The humectant is preferably

  carefully introduced into the aqueous phase during the preparation of the emulaion. The content of humectant is generally between 0.1 and 5 by weight relative to the

total weight of the emulsion.

  The usual preservatives of the technique of cosmetic or dermatological compositions can be used in the invention, and for example benzaic acid and methyl and / or propyl parahydroxybenzoates, alone or

  in combination, or chlorphenesin.

  Protective agents against ultraviolet rays can also be used. These protective agents can for example be sunscreens such as benzophenone or a benzophenone derivative, or a cinnamate and

  more particularly ethylhexyl methoxycinnamate.

  You can also use pigments forming an anti-

  ultraviolet, which can for example be chosen from the

  titanium dioxide, zinc oxide or aluminum oxide.

  The compositions can be in the form of creams, oil-in-water emulsions or water-in-oil emulsions, milks, gels, lotioris, masks, sticks or ointments, and can be used in particular for protecting the skin. against various aggressions generally resulting from the environment of the users, for example climatic aggressions (wind, cold, rain, etc.), chemical aggressions (detergents)

or pollution.

  A preferred embodiment of the invention is in the form of a hand cream, this cream being able to

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  possibly also be applied to the forearms which

  have the same skin type as the top of the hands.

  The composition of the invention proves to be particularly useful and effective for ensuring daily care of the skin, in particular in subjects with fragile skin or exposed to risks of environmental aggression or various affections. The features and advantages of this

  invention will appear in more detail in the description which

  o follows, relating to preferred embodiments.

  In these examples, the parts and percentages are expressed

  by weight, unless otherwise indicated.

Example 1

  A hand cream is prepared, using the usual techniques of the cosmetic and dermatological industry. The weight composition of the cream is indicated below. Eauq.s.p. 100.00 23 Citric acid7.50 Sadium citrate7.50 Capric and caprylic triglycerides 5.00 Ethylhexyl methoxyainnamate 5.00 Benzophenone-35.00 Hydroxyproline methylsilanol aspartate 5.00 Polymethyl methacrylate 2.00 Glycerin 3.00 Isohexadecane3.00 Ascorbyl tetra-isopalmitate1.00 PEG 30 dipolyhydroxystearate1.00 Magnesium sulLate0.80 Perfluorodecaline0.75 Phenoxyethanol / parahydroxyLenzoate 0.60 t '1L' Glabridine *. 0.50 Perfume0 40 Chlorphenesine0.20 * Aqueous solution of GlycyrrRiza glabra (Licorice)

Example 2

  In this example, a cream is prepared having the

  weight composition indicated below.

  Water q.s.p. 100.00 Citric acid 7.50 Sodium citrate 7, S0 Sorting citrate, C12-13, alkyl 10.00 Capric and caprylic triglycerides 6.00 Alkyl glucoside (C12-20) / alcohol (C14-22) 5 .00: 5 Tetrahexyl-decyl ascorbate 1.00 Butylene glycol 0.45 Hydroxyproline methylsilanol aspartate 5.00 Galacto arabinane 2.00 Ammonium succinate 5.00 Ammonium poly- (acryldimethyltauramide-CO vinylformamide) 1.00 Propylene glycol / diazolidinylurea / alkyl hydroxybenzoate 1.00 Xanthan gum 0.50 2 Glabridin 0.05 A cream having the above composition can be applied to the hands and arms in a regular thin layer

several times a day.

Claims (12)

  1. Cosmetic composition preventing symptoms of   aging, usable by topical application, charac-   terisoe in that it comprises in combination at least one alpha-hydroxy acid or one of its salts and esters and at least one silanol. 2. Composition according to claim 1, characterized in that the alpha-hydroxy acid is chosen from lactic acid, glycolic acid, mandelic acid and citric acid. 3. Composition according to claim 2, characterized in that the alpha-hydroxy acid chosen represents between 5 and % by weight of the composition.   4. Composition according to any one of the claims   previous cations, characterized in that the alpha-hydroxy   acids are present in the form of salts or esters of alpha- hydroxy acids.   5. Composition according to claim 1, characterized in that the silanol is chosen from mono-alkyl silane triols and dialkyl silane diols o the alkyl group can comprise a linear or branched chain of 1 to 12 carbon atoms. 6. Composition according to claim 5, characterized in that the silanol is chosen from methylsilanol mannuronate, ascorbyl methylsilanol, hydroxyproline   s methylsilanol, and hydroxyproline aspartate methylsilanol.   7. Composition according to any one of claims 5 and 6, characterized in that the silanol derivative represents between 1 and 20% by weight of the composition, preferably mainly between 3 and 7%.   8. Composition according to any one of the preceding claims, characterized in that it comprises   in addition to ascorbic acid or an ascorbic acid derivative.   9. Composition according to claim 8, characterized in that the ascorbic acid derivative is chosen from ascorbyl tetra-isopalmitate and tetra-hexyl decyl ascorbate. 10. Composition according to any one of the preceding claims, characterized in that it comprises in addition to depigmenting agents.   11. Composition according to claim 10, characterized   in that the depigmenting agent is glabridin.   12. Cosmetic treatment methade intended for the prevention of symptoms related to aging of the skin, by local application of a composition based on silanols and alpha-hydroxy acids according to any one of claims 1 to 11, on skin and especially on the area of the