FR2835430A1 - Composition comprising lecithin-coated nanocapsules and an acrylamide polymer, useful as a cosmetic agent in the care of sensitive skins - Google Patents

Abstract

A composition in a physiologically acceptable medium of 0.001 - 10% wt. of a homopolymer or copolymer of (meth)acrylamide, containing an aqueous suspension of nanocapsules comprising a polymeric envelope and a fatty core containing an oily solvent. The nanocapsules are coated with lecithin. An Independent claim is also included for the use of the compositions.

Description

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The present invention relates to a composition comprising, in a physiologically acceptable medium, from 0.001 to 10% by weight of at least one homopolymer or copolymer of (meth) acrylamide, and an aqueous suspension of nanocapsules comprising a polymeric shell and a core lipid containing an oily solvent, said nanocapsules being at least partially coated with lecithin. It also relates to the cosmetic use of this composition for the care of sensitive skin.

For several years, we have sought to optimize both the efficacy and the tolerance of cosmetic skincare products, which are characterized by the presence of an excipient, generally in the form of an oil-in-water emulsion or a gel , containing cosmetic assets.

In the formulation of this type of product, acrylamide-based polymers are often used which are useful as thickeners and furthermore make it possible to stabilize the emulsions. These polymers are found to be particularly interesting than other thickeners such as carbomers or polysaccharide derivatives in terms of texture and feel. The amount of these polymers that can be used is however limited. In addition, even at low concentrations, these polymers can generate discomfort sensations such as tingling, heating or tightness in sensitive skin subjects.

Moreover, it is known that the effectiveness of the active ingredients can be improved by encapsulating them in the heart or the lipid bilayer of various types of vesicles whose function is both to protect the active against the oxidation, for example, and to transport it closer to its site of action.

Among these vesicles, the nanocapsules are of particular interest, insofar as they comprise a sealed rigid membrane allowing good protection of the asset they encapsulate and are able to penetrate into the epidermis where they release their contents quickly, under the action of the enzymes present therein (when they consist of a biodegradable polymer), or in a prolonged manner (when the polymer constituting the membrane is not biodegradable).

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 In any case, the content of the nanocapsules can not, unlike other types of vesicles, be removed from the surface of the skin simply by rubbing or washing.

Various types of nanocapsules have already been described in applications EP-0 274 961, EP-0 447 318, EP-0 557 489, EP-1 025 901, FR-2 787 730 and EP-1 034 839.

These nanocapsules generally comprise, in addition to the polymer constituting their rigid membrane, at least one type of amphiphilic lipid used as a coating agent and capable of spontaneously forming in contact with water a lamellar-type Iyotropic liquid crystal phase. Its purpose is to facilitate the formation of the capsules but above all to improve the stability of the nanocapsules and to avoid the leakage of the encapsulated active agent, by depositing at the interface between the polymeric membrane and the aqueous phase in which the nanocapsules are dispersed.

Now, the Applicant has discovered with astonishment that certain nanocapsules, namely those coated with lecithin, used to limit the feelings of discomfort associated with the use of homopolymers or copolymers of acrylamide in cosmetics.

Admittedly, it is already known from US Pat. No. 6,017,549 that hydrogenated lecithin is capable of reducing the irritation due to certain active agents such as retinoids, by reinforcing the barrier properties of the skin and thereby delaying cutaneous penetration of the skin. the asset. It is also indicated that the anti-irritant effect is potentiated in the case where the asset is encapsulated, for example in microcapsules consisting of collagen and glycosaminoglycans.

Also known from the publication of Parel et al., Topical Liposomal Gel of Tretinoin for the Treatment of Acne: Research and Clinical Implications, Pharm. Dev.

Technol., 5 (4), 455-464 (2000) the use of egg yolk lecithin liposomes to reduce tretinoin irritation.

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However, it was not predictable from the above documents that the anti-irritant effect of lecithin vis-a-vis retinoids could be transposed to acrylamide polymers.

Indeed, the mode of irritation of these two types of compounds is not comparable, insofar as the irritation caused by the retinoids is due to their transformation into retinoic acid which, when it is present at too high a dose in the epidermis, leads to a release of mediators of inflammation resulting in erythema, roughness and a sensation of heating. On the contrary, on the reactive persons, the acrylamide monomers generate a so-called primary irritation, by simple contact of the monomer with the skin.

This has been corroborated by the Applicant who has demonstrated that the irritation due to retinol could be limited by inclusion thereof in nanocapsules consisting of an oxyethylenated polydimethylsiloxane (dimethicone copolyol), whereas the use of the same type of nanocapsules but containing tocopherol acetate in place of retinol, did not improve the tolerance of compositions containing a polyacrylamide. It was therefore not foreseeable that a compound (such as lecithin) known to reduce retinoid irritation would also be effective in preventing the discomfort sensations associated with acrylamide polymer-containing compositions.

In addition, the above documents do not suggest that lecithin can be used as a capsule-coating agent.

The subject of the invention is therefore a composition comprising, in a physiologically acceptable medium, from 0.001 to 10% by weight of at least one homopolymer or copolymer of (meth) acrylamide, characterized in that it contains an aqueous suspension of nanocapsules comprising a polymeric shell and a lipid core containing an oily solvent, said nanocapsules being at least partially coated with lecithin.

The homopolymers and copolymers of (meth) acrylamide that may be used according to the present invention may in particular be chosen from the group consisting of: optionally crosslinked homopolymers of (meth) acrylamide, optionally N-

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 substituted; copolymers of (meth) acrylamide with at least one monomer chosen from acrylic acid, an alkyl (meth) acrylate, sodium acrylate, ammonium acrylate, dimethyl diallyl ammonium chloride, acrylonitrile, and vinylpyrrolidone; and optionally crosslinked copolymers of (meth) acrylamide Nsubstituted with an acrylamide monomer or an ethylenically unsaturated monomer optionally oxyalkylenated and having a hydrophobic group.

According to an advantageous embodiment of the invention, the N-substituted (meth) acrylamide homopolymers or copolymers are substituted with an optionally partially neutralized alkyl sulphonic acid.

Thus, a preferred example of a N-substituted (meth) acrylamide homopolymer is a partially neutralized 2-acrylamido-2-methylpropane sulfonic acid (AMPS) crosslinked polymer.

 Examples of copolymers of (meth) acrylamide N-substituted are: - optionally crosslinked copolymers of 2-acrylamido-2-methylpropanesulphonic acid and alkyl (meth) acrylate or alkyl (meth) acrylamide optionally oxyalkylenated, including the alkyl group contains from 6 to 22 carbon atoms, such as those described in application FR-2,819,179.

 the optionally crosslinked copolymers of 2-acrylamido-2-methylpropanesulphonic acid and of acrylamide, such as those marketed in a 40% inverse emulsion by the company SEPPIC, either in an isohexadecane 1 water mixture (Simulgel 600), or in a isoparaffin 1 water mixture (Sepigel 305).

 The nanocapsules used in the composition according to the invention are substantially spherical particles having an average particle size of between 10 nm and 1000 nm and more particularly between 30 nm and 500 nm, which comprise a polymeric shell or shell containing a lipid core containing an oily solvent, said envelope being coated with an amphiphilic lipid forming a lyophilic liquid crystal phase of lamellar type, which amphiphilic lipid comprises lecithin.

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These nanocapsules can be of any known type and prepared according to any known method.

By way of example, mention may be made of the nanocapsules described in patent application EP-0274961, the nanocapsules provided with a lamellar coating described in application EP-0780115, the nanocapsules whose continuous polymeric envelope insoluble in water is composed of polyesters as described in the applications EP-1025901, FR-2787730 and EP-1034839, or else the biodegradable nanocapsules described in the patent application FR-2,659,554, or non-biodegradable described in the patent application WO -93/05753.

Nanocapsules made of biodegradable polymers penetrate the skin and degrade in the epidermis under the action of the enzymes that are present, whereas the nanocapsules in non-biodegradable polymers only penetrate the superficial layers of the stratum corneum and are eliminated naturally during renewal of the skin.

The use of a particular type of polymer therefore depends on the intended mode of action for the active agent possibly contained in these nanocapsules, and therefore on the desired cosmetic or dermatological effect for the composition according to the invention.

1) As biodegradable polymers, it is possible to use any polymer that may be degraded by the skin enzymes, and in particular those mentioned in the document EP-A-447318. Poly-L-and bi-degradable polymers may be mentioned in particular as biodegradable polymers. DL-lactides and polycaprolactones, polyglycolides and their copolymers, as well as polymers derived from the polymerization of alkyl cyanoacrylate (the alkyl chain having 2 to 6 carbon atoms).

2) Among the other biodegradable polymers that can be used to form the nanocapsules according to the invention, mention may be made of synthetic water-dispersible anionic polymers such as, in particular, polyesters, poly (ester amides), polyurethanes and vinyl copolymers, all of which have carboxylic acid and / or sulfonic acid functions,

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 and natural water-dispersible anionic polymers selected from shellac resin, sandarac gum and dammars.

The anionic polyesters are obtained by polycondensation of aliphatic, cycloaliphatic and / or aromatic carboxylic acid diacids and aliphatic, cycloaliphatic and / or aromatic diols or polyols, a certain number of these diacids and diols additionally bearing a carboxylic acid or free sulfonic acid function or in the form of salt.

l'acide adipique, l'acide pimélique, l'acide subérique, l'acide sébacique, l'acide téréphtalique, l'acide isophtalique ou l'anhydride de celui-ci. Comme diols aliphatiques, on peut citer l'éthylèneglycol, le diéthylèneglycol, le triéthylèneglycol et le tétraéthylèneglycol, le di (hydroxyméthyl) cyclohexane, le diméthylolpropane ou le 4,4'- (1-méthylpropylidène) -bisphénol. As dicarboxylic acids, there may be mentioned succinic acid, glutaric acid,

adipic acid, pimelic acid, suberic acid, sebacic acid, terephthalic acid, isophthalic acid or anhydride thereof. As aliphatic diols, mention may be made of ethylene glycol, diethylene glycol, triethylene glycol and tetraethylene glycol, di (hydroxymethyl) cyclohexane, dimethylolpropane or 4,4'- (1-methylpropylidene) bisphenol.

The polyol monomers are, for example, glycerol, pentaerytritol and sorbitol. The comonomers making it possible to introduce anionic groups are, for example, dimethylolpropionic acid, trimellitic acid or mellitic anhydride, or a diol or dicarboxylic acid compound additionally bearing a SO 3 M group where M represents a hydrogen atom or a hydrogen atom. an alkali metal, such as sodium 1,5-dihydroxypentane-3-sulfonate or sodium 1,3-dicarboxybenzene-5-sulfonate.

The poly (ester amides) which can be used as other synthetic water-dispersible anionic polymers have a structure similar to that of the polyesters described above, but in addition contain units derived from a diamine such as hexamethylenediamine, meta-or para-phenylenediamine, or an amino alcohol such as methanolamine.

According to a preferred embodiment of the invention, the water-dispersible anionic polymer is chosen from aromatic, cycloaliphatic and / or aliphatic polyesters bearing sulphonic acid functions, that is to say copolyesters comprising at least units derived from isophthalic acid, sulphate

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 aryldicarboxylic and diethylene glycol. Among these, polyesters comprising units derived from isophthalic acid, sulfo-isophthalic acid, diethylene glycol and 1,4di (hydroxymethyl) cyclohexane, such as those marketed under the names AQ29, may be particularly mentioned. , AQ38, AQ48 ULTRA, AQ 55S, AQ1350, AQ1045, AQ1950 and AQ14000 by EASTMAN CHEMICAL.

These polyesters may also contain units derived from ethylene glycol, triethylene glycol and / or tetraethylene glycol and terephthalic acid such as those sold under the names POLYCARE PS 20, POLYCARE PS30 and POLYCARE PS 32 by the company RHONE POULENC. The proportion of units derived from sulphoisophthalic acid is generally between 2 and 20% by weight.

néopentylglycol. Les éther-diols sont des di-, tri-ou tétra- (alkylène en C2-4) -glycols tels que le diéthylèneglycol, le triéthylèneglycol, le tétraéthylèneglycol, le dipropylèneglycol, le tripropylèneglycol, le tétrapropylèneglycol ou le dibutylèneglycol, letributylèneglycol ou le tétrabutylèneglycol. Les triols utilisés sont généralement choisis parmi le glycérol, le triméthyloléthane et le triméthylolpropane. 3) According to one variant of the invention, the biodegradable polymer constituting the shell of the nanocapsules may be a polyester of the poly (alkylene adipate) type, that is to say either a homopolymer of adipic acid and an alkane diol, a poly (ester ether) type copolymer, linear or branched, obtained from adipic acid and one or more alkanediols and / or ether-diols and / or triols. The alkanediols used for the preparation of said poly (alkylene adipate) are straight or branched chain C 1 -C 18 alkanediols selected from ethylene glycol, propylene glycol, 1,3-propandiol, 1,4-butanediol, 1,5-pentandiol, 1,6-hexanediol and

neopentylglycol. The ether diols are di-, tri- or tetra- (C2-4 alkylene) glycols such as diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol or dibutylene glycol, butylene glycol glycol or tetrabutylene glycol. . The triols used are generally chosen from glycerol, trimethylolethane and trimethylolpropane.

The fraction of the branching units derived from the above triols generally does not exceed 5 mol% relative to all the units derived from diols and triols. According to a preferred embodiment of the present invention, the envelope of the nanocapsules is formed by a poly (ethylene adipate) or a poly (butylene adipate).

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The poly (alkylene adipates) used in the present invention have a weight average molecular weight (measured by gel permeation chromatography) which is preferably between 2000 and 50,000, more preferably between 5,000 and 15,000.

A whole range of products of different chemical compositions and of different molar masses is marketed under the name FOMREZ &commat; by the company WITCO. SCIENTIFIC POLYMER PRODUCTS sells under the name POLY (ETHYLENE) ADIPATE tE a poly (ethylene adipate) with a weight average molecular weight (determined by GPC) of about 10,000.

4) Another class of polymers that can be used to form the envelope of the nanocapsules according to the invention consists of dendritic polymers. These are hyperbranched polymers having the chemical structure of a polyester and which are terminated with hydroxyl groups optionally modified with at least one chain terminating agent. The structure and the preparation of such polymers is described in patent applications WO-A-93/17060 and WO 96/12754.

More specifically, the dendritic polymers that can be used in the compositions of the present invention can be defined as highly branched polyester-type macromolecules, consisting of: a central unit derived from an initiator compound carrying one or more hydroxyl functional groups (a) chain-extension units derived from a chain-extending molecule carrying a carboxyl function (b) and at least two hydroxyl functions (c), each of the hydroxyl functions (a) of the central molecule being the point; starting of a polycondensation reaction (by esterification) which starts with the reaction of the hydroxyl functions (a) of the central molecule with the carboxyl functions (b) of the chain lengthening molecules, and then proceeds by reaction of the functions carboxyl (b) with the hydroxyl functions (c) of chain extension molecules.

A "generation X" dendrimer is called a hyperbranched polymer prepared by X condensation cycles, each cycle consisting in reacting all the functions

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 reactants of the central unit or polymer with one equivalent of a chain extender molecule. The initiator compound bearing one or more hydroxyl functions and forming the central unit around which the dendritic structure will be constructed is a mono-, di- or polyhydroxylated compound. It is generally selected from: (a) a monofunctional alcohol, (b) an aliphatic, cycloaliphatic or aromatic diol, (c) a triol, (d) a tetrol, (e) a sugar alcohol, (f) anhydro -enna-heptitol or dipentaerythritol, (g) an-alkylglycoside, (h) a polyalkoxylated polymer obtained by polyalkoxylation of one of the alcohols (a) to (g), having a molar mass of at most 8000.

triméthyloléthane, le triméthylolpropane, un triméthylolpropane alcoxylé, le glycérol, le néopentylglycol, le diméthylolpropane et le 1,3-dioxane-5, 5-diméthanol. Examples of preferred initiator compounds for preparing the dendritic polyesters used in the present invention are ditrimethylolpropane, ditrimethylolethane, dipentaerythritol, pentaerythritol, alkoxylated pent rhyththol, and the like.

trimethylol ethane, trimethylolpropane, alkoxylated trimethylolpropane, glycerol, neopentylglycol, dimethylolpropane and 1,3-dioxane-5,5-dimethanol.

The hydroxyl initiator compounds forming the central unit of the future dendrimer are reacted with molecules known as chain-extending molecules which are diol monoacid-type compounds chosen from: monocarboxylic acids containing at least two hydroxyl functions, and monocarboxylic acids having at least two hydroxyl functions of which one or more carries a hydroxyalkyl substituent.

a, a-bis (hydroxyméthyl)-butyrique, l'acide a, a, a-tris (hyd roxyméthyl) -acétique, l'acide a, a-bis (hydroxyméthyl)-valérique, l'acide a, a-bis (hydroxy)-propionique et l'acide 3, 5 dihydroxybenzoïque. Preferred examples of such compounds are dimethylolpropionic acid,

α, α-bis (hydroxymethyl) -butyric acid, α, α, α-tris (hyd roxymethyl) -acetic acid, α, α-bis (hydroxymethyl) -valeric acid, α, α-bis acid (hydroxy) -propionic acid and 3,5-dihydroxybenzoic acid.

According to a particularly preferred embodiment of the present invention, the initiator compound is chosen from trimethylolpropane, pentaerythritol and a

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 ethoxylated pentaerythritol, and the chain extender molecule is dimethylolpropionic acid.

Some of the terminal hydroxyl functions of polyester-type dendritic polymers used in the nanocapsules of the present invention may carry substituents derived from at least one chain terminator. The fraction of these terminal hydroxyl functions bearing a chain termination unit is generally between 1 and 90 mol%, preferably between 10 and 50 mol%, based on the total number of terminal hydroxyl functions. The choice of an appropriate chain terminator allows the physicochemical properties of the dendritic polyesters used in the compositions of the present invention to be modified as desired. The chain terminating agent can be selected from a wide variety of compounds capable of forming covalent bonds with terminal hydroxyl functions.

These compounds include, in particular: i) saturated or unsaturated aliphatic or cycloaliphatic monocarboxylic acids or anhydrides; ii) saturated or unsaturated fatty acids; iii) aromatic monocarboxylic acids; iv) monomeric or oligomeric diisocyanates or adducts; of these, v) epihalohydrins, vi) the glycidyl esters of a monocarboxylic acid or of a C 6 fatty acid, the glycidyl ethers of monovalent alcohols in Cul-24, viii) the addition products derivatives of a saturated or unsaturated aliphatic or cycloaliphatic mono-, di- or polycarboxylated acid, or corresponding anhydrides, ix) adducts derived from a mono-, di- or polycarboxylated aromatic acid or corresponding anhydrides, x) epoxides of a C3-24 unsaturated monocarboxylic acid or a corresponding triglyceride, xi) aliphatic or cycloaliphatic monofunctional alcohols, saturated or unsaturated, xii) monofunctional alcohols aromatic functionalities,

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 xiii) adducts derived from a saturated or unsaturated mono-, di- or polyfunctional, aliphatic or cycloaliphatic alcohol, and xiv) adducts derived from a mono-, di- or polyfunctional aromatic alcohol.

dioxane-5-méthanol, l'éther diallylique de triméthylolpropane, l'éther triallylique de pentaérythritol, le triacrylate de pentaérythritol, le triacrylate de pentaérythritol triéthoxylé, le toluène-2, 4-diisocyanate, le toluène-2, 6-diisocyanate, l'hexaméthylène- diisocyanate ou l'isophorone-diisocyanate. Examples of chain terminators include auric acid, flaxseed fatty acids, soybean fatty acids, tallow fatty acids, dehydrogenated castor oil fatty acids, crotonic acid, capric acid, caprylic acid, acrylic acid, methacrylic acid, benzoic acid, para-tert-butylbenzoic acid, abietic acid, sorbinic acid, 1-chloro-2,3-epoxypropane, 1,4-dichloro-2,3-epoxybutane, epoxidized soybean fatty acids, trimethylolpropane diallyl ethereal maleate, 5-methyl-1,3-dioxane -5-methanol, 5-ethyl-1, 3-

dioxane-5-methanol, trimethylolpropane diallyl ether, pentaerythritol triallyl ether, pentaerythritol triacrylate, triethoxylated pentaerythritol triacrylate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, hexamethylene diisocyanate or isophorone diisocyanate.

Of these chain terminators, particularly preferred are capric acid and caprylic acid or a mixture thereof.

The dendritic polymers of the polyester type with terminal hydroxyl functions and optionally carrying chain termination groups are known and are marketed by the company PERSTORP.

Particularly preferred polymers used in the present invention are: - a dendritic polyester obtained by polycondensation of dimethylolpropionic acid on trimethylolpropane and free of chain terminating agents, for example that marketed under the name "BOLTORN &commat; H40 (TMP core ) "by the company PERSTORP; a dendritic polyester obtained by polycondensation of dimethylolpropionic acid on polyoxyethylenated pentaerythritol (on average 5 units of ethylene oxide on each hydroxyl function), free of chain terminating agent, for example that marketed under the name "BOLTORN & commat H30 "by the company PERSTORP;

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 a dendritic polyester of generation 3 obtained by polycondensation of dimethylolpropionic acid on polyoxyethylenated pentaerythritol (on average 5 units of ethylene oxide on each hydroxyl function), of which 50% of the hydroxyl functions are esterified with C 8 acids. and in particular caprylic and caprylic acids ("BOLTORN &commat; H30 (esterified)" sold by the company PERSTORP).

Of these three polymers, the last is particularly preferred.

5) The non-biodegradable polymers that may be used according to the invention may be chosen from any polymer that is not degraded by the skin enzymes, and in particular those mentioned in document EP-A-557489. Among the non-biodegradable polymers, mention may in particular be made of copolymers of vinyl chloride and of vinyl acetate, and copolymers of methacrylic acid and methacrylic acid methyl ester, polyvinyl acetate phthalate, and the like. cellulose acetate-phthalate, cross-linked polyvinylpyrrolidone-vinyl acetate copolymers, polyethylenesvinylacetates, polyacrylonitriles, polyacrylamides, polyethylene glycols, polyamides, polyethylenes, polypropylenes and organopolysiloxanes, without this list being limiting.

- les 2-alkyl alcanols, et de préférence : le butyloctanol, l'hexyldécanol, l'octyldécanol, l'alcool isostéarylique, l'octyldodécanol, le décyltétradécanol, le undécylpentadécanol, le dodécylhexadécanol, le tétradécyloctadécanol, l'hexyldécyloctadécanol, le tétradécyleicosanol, le cétylarachidol et le mélange d'alcools iso-cétylique, isostéarylique et iso-arachidylique. Tous ces composés sont disponibles dans le commerce, auprès de CONDEA VISTA sous la dénomination commerciale Isofol&commat;, de EXXON CHEMICAL sous la dénomination Exxal&commat; ou de JARCHEM sous la dénomination Jarcot. On peut également utiliser le composé disponible auprès de HENKEL sous la dénomination commerciale EUTANOL G. Comme esters desdits alcools, on peut citer : t'octanoate d'octyldodécyle ; le caprylate d'hexyldécyle ; le laurate d'hexyldécyle le palmitate d'hexyldécyle le stéarate d'hexyldécyle ; et The nanocapsules capable of being formed from the above polymers comprise, in their lipid core, an oily solvent which may especially be chosen from those given by way of example below:

the 2-alkyl alkanols, and preferably: butyloctanol, hexyldecanol, octyldecanol, isostearyl alcohol, octyldodecanol, decyltetradecanol, undecylpentadecanol, dodecylhexadecanol, tetradecyloctadecanol, hexyldecyloctadecanol, tetradecylsilicane, cetylarachidol and the mixture of iso-cetyl, isostearyl and iso-arachidyl alcohols. All these compounds are commercially available from CONDEA VISTA under the trade name Isofol &commat; EXXON CHEMICAL under the name Exxal &commat; or JARCHEM under the name Jarcot. It is also possible to use the compound available from HENKEL under the trade name EUTANOL G. As esters of said alcohols, mention may be made of: octyldodecyl octanoate; hexyldecyl caprylate; hexyldecyl laurate, hexyldecyl palmitate and hexyldecyl stearate; and

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 octyldodecyl meadowfoamate, which is an ester of octyldodecanol and fatty acids derived from meadowfoam germ oil Alba; esters of fatty acids or of fatty alcohols, of which: isopropyl palmitate, isostearyl neopentanoate and octyl palmitate; the N-acylated amino esters of fatty alcohols, preferably isopropyl N-lauryl sarcosinate; triglycerides and oils containing them, in particular octanoic acid triglycerides or sunflower, corn, soya, squash, grape seed, sesame, hazelnut, apricot or macadamia oils, of arara, castor oil, avocado, triglycerides of caprylic / capric acids, such as those sold by Stearineries Dubois or those sold under the names Miglyol 810,812 and 818 by the company Dynamit Nobel, jojoba oil, and shea butter oil; and the liquid ethers of fatty alcohols and of polypropylene glycol, advantageously the stearyl ether of polypropylene glycol containing 15 propylene glycol units.

These examples are not, however, limiting.

A preferred polymer for use in the present invention is polycaprolactone.

The preparation process used for the production of the nanocapsules is preferably that described in one of the applications cited above, in particular in the application EP-0274961.

A particular process comprises the following steps: (a) the oily solvent and the optional asset to be encapsulated are mixed with a water-miscible organic solvent (for example acetone), with the polymer which will form the nanocapsule shell and with lecithin, so as to form an organic phase; (b) this organic phase is introduced with stirring into an aqueous phase containing a hydrophilic surfactant. A spontaneous emulsion then forms. The water insoluble polymer precipitates around the oily globule and the lecithin forms a liquid crystal phase coating the oily globule encapsulated by the polymer;

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 (c) the organic solvent is evaporated and a part of the water, in order to concentrate the suspension of nanocapsules. A suspension of nanocapsules containing about 5% by weight of the oily solvent mixture and optionally encapsulated active agent is generally obtained.

The lecithin used in step (a) above may be any type of lecithin, hydrogenated or not, and it includes both natural and synthetic phosphatides. Thus, the term "lecithin" includes, in particular, phosphatidylcholine, which is a glycerin esterified with a colic ester of phosphoric acid and two fatty acids which are generally saturated or unsaturated fatty acids, containing from 16 to 20 carbon atoms and up to with four double bonds. Mention may also be made of glycerol esters with two fatty acids as defined above, but in which the choline is replaced by ethanolamine (cephalin) or serine (phosphatidyl serine) or inositol (phosphatidyl inositol). Among the types of natural lecithins, those derived from sunflower seeds, soya beans or cottonseed are particularly suitable.

Various types of lecithins are marketed, in particular, by the companies LUCAS MEYER and AMERICAN LECITHIN.

It is preferred to use in the present invention lecithins soy or egg enriched or not phosphatidyl choline and more preferably soy lecithin containing at least 45% by weight of phosphatidylcholine which is sold in particular by the company LUCAS MEYER under the trade name EPIKURON 145V.

citer : les 3-0 alcanoyl 7-hydroxy DHEA, les 3-0 alcanoyl 7-alcanoyloxy DHEA, et la 7- Furthermore, the active agent optionally contained in the nanocapsules according to the invention may be any compound having a beneficial effect on the skin and may in particular be chosen from vitamins and their liposoluble derivatives, DHEA (dehydroepiandrosterone) and its derivatives, and ceramides. By way of nonlimiting example of vitamins and derivatives, mention may be made of: retinol and its esters, in particular palmitate and retinyl caprylate; liposoluble derivatives of ascorbic acid, in particular ascorbyl palmitate; tocopherol and its esters, in particular tocopheryl acetate; vitamin F (linoleic acids, linoleic); vitamin K (phytomenadione or menadione). As examples of derivatives of DHEA, it is possible to

3-0 alkanoyl 7-hydroxy DHEA, 3-alkanoyl 7-alkanoyloxy DHEA, and 7-

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 hydroxy DHEA, without this list being limiting. Ceramides that may be mentioned include ceramides of type H, in particular 2-oleamido-1,3-octadecanediol, ceramides of the type I), in particular ceramide 3 marketed by COSMOFERM, ceramides of type V, in particular hydroxypalmitoyl sphinganine described in particular in application EP-0647617, and mixtures thereof.

Finally, the external aqueous phase containing the suspension of nanocapsules may contain, as indicated in step (b) of the above process, a hydrophilic surfactant soluble in water, such as a poloxamer, an alkyl ester or an alkyl ether. polyol, to facilitate the formation of nanocapsules. By water-soluble surfactant is meant that it is soluble to at least 1% in water, the resulting solution must be perfectly clear. Poloxamers are preferred for use in the present invention.

The composition according to the invention is preferably suitable for topical application to the skin, including the scalp.

It therefore contains a physiologically acceptable medium, that is to say, compatible with the skin and its integuments (hair, hair, eyelashes, nails) and possibly with the mucous membranes, especially the lips.

This composition comprises an amount of acrylamide polymer sufficient to achieve the desired (thickening or other) effect, and an amount of nanocapsules coated with lecithin effective to prevent irritation due to the acrylamide polymer in the composition.

By way of example, the acrylamide polymer may represent from 0.001 to 10% of the total weight of the composition and the nanocapsules from 0.1 to 50% by weight, better still from 0.5 to 25% of the total weight of the composition. the composition, lecithin representing from 0.01 to 10% of the total weight of the composition.

 The composition according to the invention may be in any of the galenical forms conventionally used for topical application and especially in the form of aqueous gels, aqueous or aqueous-alcoholic solutions. They can also, by adding a

<Desc / Clms Page number 16>

 fatty or oily phase, be in the form of dispersions of the lotion or serum type, emulsions of liquid or semi-liquid consistency of the milk type, obtained by dispersion of a fatty phase in an aqueous phase (O / W) or conversely (E / H), or suspensions or emulsions of soft, semi-solid or solid consistency of the cream or gel type, or multiple emulsions (E / H / E or H / E / H), microemulsions or wax dispersions / aqueous phase. These compositions are prepared according to the usual methods.

According to a preferred embodiment of the invention, the composition is in the form of an emulsion, advantageously in the form of an oil-in-water emulsion.

When the composition is in emulsion form, the proportion of the oily phase of the emulsion may range, for example, from 5% to 80% by weight, and preferably from 5% to 50% by weight relative to the total weight of the composition. . The oils, the emulsifiers and the co-emulsifiers used in the composition in emulsion form are chosen from those conventionally used in the cosmetic or dermatological field. The emulsifier and the co-emulsifier are generally 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 further contain lipid vesicles such as liposomes, niosomes, or oleosomes.

As fats which can be used in the invention, it is possible to use the oils and in particular the mineral oils (liquid petroleum jelly), the oils of vegetable origin (avocado oil, soya oil), the oils of animal origin (lanolin ), synthetic oils (perhydrosqualene), silicone oils (cyclomethicone) and fluorinated oils (perfluoropolyethers). It is also possible to use fatty alcohols such as cetyl alcohol, fatty acids, waxes and gums, and in particular silicone gums, as fatty substances.

Examples of emulsifiers and coemulsifiers that can be used in the invention include, for example, fatty acid and polyethylene glycol esters, such as PEG-100 stearate, PEG-50 stearate and PEG-40 stearate; fatty acid esters of polyol such as glyceryl stearate, sorbitan tristearate and stearates of

<Desc / Clms Page number 17>

 oxyethylenated sorbitan available under the trade names Tween &commat; 20 or Tween 60, for example; and their mixtures.

As hydrophilic gelling agents, mention may in particular be made of carboxyvinyl polymers (carbomer), acrylic copolymers such as copolymers of acrylates / alkylacrylates, polyacrylamides, polysaccharides, natural gums and clays, and, as lipophilic gelling agents, it is possible to mention mention modified clays such as bentones, metal salts of fatty acids and hydrophobic silica.

sels et/ou ses dérivés, l'acide ursolique et ses sels, l'acide oléanolique et ses sels, l'acide bétulinique et ses sels ; les extraits de Paeonia suffruticosa et/ou lactiflora, de Rosmarinus officinalis, d'épilobe, de Pygeum, de Boswellia serrata, de Centipeda cunnighami, d'Helianthus annuus, de Cola nitida, de clou de girofle et de Bacopa moniera ; les sels de l'acide salicylique et en particulier le salicylate de zinc ; les extraits d'algues, en particulier de Laminaria saccharina ; l'huile de Canola, de Tamanu, de calophillum, les huiles insaturées en oméga 3 telles que les huiles de rosier muscat, de cassis, d'ecchium, de poisson ; l'a-bisabolol et les extraits de camomille ; l'allantoin ; le diesterphosphorique de vitamine E et C ; la capryloyl glycine ; les tocotrienols ; le piperonal ; l'aloe vera ; les phytostérols ; la cortisone, l'hydrocortisone, l'indometacine

la béta méthasone ; une souche de Vitreoscilla filiformis, un extrait aqueux d'Iris pallida et un extrait hydroglycolique de pétales de Rosa gallic. As active agents, mention may in particular be made of soothing agents which may especially be chosen from: pentacyclic triterpenes, such as ss-glycyrrhetinic acid and its

salts and / or derivatives thereof, ursolic acid and its salts, oleanolic acid and its salts, betulinic acid and its salts; extracts of Paeonia suffruticosa and / or lactiflora, Rosmarinus officinalis, willowherb, Pygeum, Boswellia serrata, Centipeda cunnighami, Helianthus annuus, Cola nitida, clove and Bacopa moniera; salts of salicylic acid and in particular zinc salicylate; algae extracts, in particular Laminaria saccharina; Canola oil, Tamanu oil, Calophillum oil, unsaturated omega 3 oils such as rose hip, blackcurrant, ecchium, fish oil; a-bisabolol and chamomile extracts; the allantoin; diesterphosphoric vitamin E and C; capryloyl glycine; tocotrienols; the piperonal; the aloe vera ; phytosterols; cortisone, hydrocortisone, indometacine

beta methasone; a strain of Vitreoscilla filiformis, an aqueous extract of Iris pallida and a hydroglycolic extract of Rosa gallic petals.

The composition according to the invention can be used for cosmetic purposes, for the care of sensitive skin.

The invention therefore also relates to the cosmetic use of the composition as defined above for the care of sensitive skin.

It also relates to the use of an aqueous suspension of nanocapsules comprising a polymeric envelope and a lipid core containing an oily solvent, said nanocapsules being at least partially coated with lecithin, for

<Desc / Clms Page number 18>

 preventing or reducing the irritation or discomfort sensations due to a composition comprising at least one homopolymer or copolymer of (meth) acrylamide in a physiologically acceptable medium.

The invention will now be illustrated by the following nonlimiting examples. In these examples, the amounts are indicated in weight percent.

EXAMPLES Example 1: Demonstration of the Anti-Irritant Effect Two formulas were prepared having the composition shown in Table 1 below and differing only in the fact that Formula 1 contained 10% by weight of polycaprolactone nanocapsules coated with soy lecithin, containing vitamin E, while Formula 2 does not contain any.

<Tb>
<Tb>

Phase <SEP> Material <SEP> Formula <SEP> 1 <SEP> Formula <SEP> 2
<tb> A <SEP> Polyacrylamide / Acrylamido <SEP> 2 <SEP> Me <SEP> Propane <SEP> sulfonate <SEP> of <SEP> 2% <SEP> 2%
<tb> Na <SEP> in <SEP> emulsion <SEP> inverse <SEP> to <SEP> 40% <SEP> in <SEP> iso <SEP> paraffin / water
<tb> B <SEP> Water <SEP> Distilled <SEP> 71. <SEP> 4% <SEP> 71.4%
<tb> Preservatives <SEP> 0. <SEP> 5% <SEP> 0.5%
<tb> Extract <SEP> aqueous <SEP> of <SEP> young <SEP> tissues <SEP> of <SEP> Beech <SEP> 4% <SEP> 4%
<tb> Extract <SEP> of seaweed <SEP> 1% <SEP> 1%
<tb> Protein <SEP> of <SEP> soya <SEP> 5% <SEP> 5%
<tb> Water-soluble <SEP> fraction <SEP> of <SEP> corn <SEP> in <SEP> water <SEP> 1% <SEP> 1%
<tb> C <SEP> Water <SEP> distilled <SEP> 5% <SEP> 5%
<tb> Hyaluronate <SEP> of <SEP> Na <SEP> 0. <SEP> 1% <SEP> 0. <SEP> 1%
<tb> D <SEP> Nanocapsules <SEP> Acetate <SEP> of <SEP> Vitamin <SEP> E <SEP> (5%) <SEP> 10% <SEP> 0%
<tb> polycaprolactone <SEP> (1 <SEP>%) <SEP> and <SEP> lecithin <SEP> from <SEP> soya <SEP> (1 <SEP>%)
<Tb>
Table 1

<Desc / Clms Page number 19>

 These formulas were tested on a panel of 10 people with sensitive skin (grade 2 or 3) for 15 days. Each day, after each application (2 consecutive applications per hemi-age / day), on each panelist, a search for functional signs of the irritation is performed as well as a dermatological examination of the skin. The functional signs sought were: tingling, pruritus, sensations of heating, cooking or burning and tugging. For each functional sign, the investigator evaluated: - the intensity of the signs - the time of appearance of the signs - the duration.

The scoring scale of the signs was as follows: - Score 0: absence - Score 1: very light intensity - Score 2: light intensity - Score 3: moderate intensity - Score 4: severe to very severe intensity The intensity of signs and symptoms their duration determined a grade of discomfort.

The grade obtained was then weighted by a different coefficient according to the signs.

Physical signs were also sought. These were: - Erythema
Drought - Roughness For each item the scale of the scores was as follows: - Score 0: absence - Score 1: very light intensity - Score 2: light intensity - Score 3: moderate intensity - Score 4: severe to very severe intensity The score obtained was then weighted by a different coefficient according to the signs.

Calculation of the weighted scores:

<Desc / Clms Page number 20>

- Functional Signs: Functional Weighted Overall Score = E Functional Weighted Score - Physical Signs: Physical Overall Weighted Score = S Weighted Physical Score 5Calculated Tolerance Index by Subject: (Functional Overall Weighted Score + Physical Overall Weighted Score)
The average tolerance index corresponds to:
E Tolerance Index by Subject / Number of Subjects The results are collated in Table 2 below.

<Tb>
<Tb>

Time <SEP> Formula <SEP> 1 <SEP> Formula <SEP> 2
<tb> J1 <SEP> TO <SEP> 1. <SEP> 3 + 2. <SEP> 87 <SEP> 1. <SEP> 3 + 2. <SEP> 87
<tb> J1 <SEP> T10 <SEP><SEP> 1. <SEP> 402 <SEP>: <SEP> 1. <SEP> 90 <SEP> 2. <SEP> 4 <SEP> + <SEP> 2. <SEP> 12
<tb> J2 <SEP> T10 <SEP> min <SEP> 2. <SEP> 30 + 2. <SEP> 87 <SEP> 3. <SEP> 00 + 3. <SEP> 23
<tb> J3 <SEP> T10 <SEP><SEP> 1. <SEP> 90 + 2. <SEP> 28 <SEP> 3. <SEP> 60 + 3. <SEP> 03
<tb> J4 <SEP> T10 <SEP><SEP> 1. <SEP> 10 + 1. <SEP> 97 <SEP> 1. <SEP> 80 + 2. <SEP> 39
<tb> J5 <SEP> T10 <SEP> min <SEP> 0. <SEP> 90 + 2. <SEP> 23 <SEP> 1. <SEP> 90 + 2. <SEP> 51
<tb> J8 <SEP> T10 <SEP><SEP> 1. <SEP> 10 + 2. <SEP> 18 <SEP> 2. <SEP> 00 + 2. <SEP> 79
<tb> J9 <SEP> T10 <SEP><SEP> 1.30 <SEP> ~ SEP> 1.83 <SEP> 1.40 <SEP> ~ SEP> 1. <SEP> 78
<tb> J10 <SEP> T10 <SEP> min <SEP> 1. <SEP> 90 + 3. <SEP> 14 <SEP> 2. <SEP> 00 + 2. <SEP> 75
<tb> J11 <SEP> T10 <SEP><SEP> 1. <SEP> 70 + 2. <SEP> 91 <SEP> 2. <SEP> 10 + 2. <SEP> 81
<tb> J12 <SEP> T10 <SEP> min <SEP> 1. <SEP> 702 <SEP>: <SEP> 2. <SEP> 63 <SEP> 2. <SEP> 40 <SEP> + <SEP> 2. <SEP> 41
<tb> J15 <SEP> T10 <SEP><SEP> 1.20 <SEP> ~ SEP> 1.75 <SEP> 1.80 <SEP> ~ <SEP> 1. <SEP> 99
<Tb>

Table 2
Tolerance index These results are used to plot the curves shown in the attached figure, on which the diamonds correspond to the values obtained with the formula 1 and the squares to the values obtained with the formula 2.

<Desc / Clms Page number 21>

The calculation of the areas under these curves leads to an overall average of 6. 54 +/- 0. 62 for formula 1 and an average of 7. 42 +/- 0. 79 for the formula 2. The comparison of the averages of the areas is made using a Student's parametric test on paired samples (risk Cree = 5%). The difference between the 2 values is significant with a significance of 6. 10-5.

It is thus clear from this test that the nanocapsules coated with a lamellar liquid crystal phase composed of lecithin, have an anti-irritant activity with respect to a composition containing an acrylamide copolymer.

EXAMPLE 2 Cosmetic Composition An aqueous suspension of nanocapsules having the following composition is prepared:

<Tb>
<tb> Octyldodecanol <SEP> 3.5 <SEP>%
<tb> Polycaprolactone <SEP> 1.0 <SEP>%
<tb> Oleamido-1, <SEP> 3-octadecanediol <SEP> 1.0 <SEP>%
<tb> Ceramide <SEP> 3 <SEP> 0.25 <SEP>%
<tb> Hydroxypalmitoyl <SEP> sphinganine <SEP> 0.25 <SEP>%
<tb> Lecithin <SEP> of <SEP> soya <SEP> 1.0 <SEP>%
<tb> Poloxamer <SEP> 188 <SEP> 0, <SEP> 5 <SEP>%
<tb> Dimethicone <SEP> copolyol <SEP> 0.5 <SEP>%
<tb> Preservatives <SEP> 1, <SEP> 0 <SEP>%
<tb> Water <SEP> 91.5 <SEP>%
<Tb>
The ceramides, octyldodecanol, polycaprolactone, the silicone surfactant and the soy lecithin are solubilized in 200 ml of acetone. This clear solution is then introduced, with stirring in the magnetic bar in 400 ml of water containing poloxamer 188. A spontaneous emulsion is formed. Acetone is evaporated under reduced pressure and some of the water. A suspension of nanocapsules whose size is 290 nm is obtained. The preservatives are then added by simple dissolution.

<Desc / Clms Page number 22>

The composition below is then prepared in a conventional manner for the skilled person. The ingredients are identified according to the CTFA nomenclature.

<Tb>
<Tb>

Glycerine <SEP> 5 <SEP>%
<tb> Preservatives <SEP> 1 <SEP>%
<tb> Disodium <SEP> EDTA <SEP> 0.2 <SEP>%
<tb> Carbomer <SEP> 0.5 <SEP>%
<tb> Triethanolamine <SEP> 0, <SEP> 25%
<tb> Ammonium <SEP> polyacryloyidimethyl <SEP> taurate * <SEP> 0.3 <SEP>%
<tb> Sodium <SEP> Hyaluronate <SEP> 0.1 <SEP>%
<tb> Vegetable oils <SEP><SEP> 3 <SEP>%
<tb> Acrylamide / sodium <SEP> acryloyldimethyltaurate
<tb> and <SEP> isododecane <SEP> and <SEP> polysorbate-80 ** <SEP> 2 <SEP>%
<tb> Cyclopentasiloxane <SEP> and <SEP> dimethiconol <SEP> 3 <SEP>%
<tb> Hydrolyzed <SEP> wheat <SEP> flour <SEP> (in <SEP> material <SEP> active) <SEP> 0.015%
<tb> Paeonia <SEP> suffruticosa <SEP> root <SEP> extract
<tb> (in <SEP> material <SEP> active) <SEP> 0.005%
<tb> Rosa <SEP> gallic <SEP> flower <SEP> extract <SEP> (in <SEP> material <SEP> active) <SEP> 0,025%
<tb> Stearalkonium <SEP> hectorite <SEP> 0, <SEP> 45%
<tb><SEP> aqueous suspension <SEP> of <SEP> nanocapsules <SEP> 5 <SEP>%
<tb> Water <SEP> qsp <SEP> 100 <SEP>%
<Tb>
* Hostacerin AMPS provided by CARIANT ** Simulgel 600 provided by SEPPIC The above composition is a moisturizing night cream for the care of sensitive skin.

Claims (20)

 1. A composition comprising, in a physiologically acceptable medium, from 0.001 to 10% by weight of at least one homopolymer or copolymer of (meth) acrylamide, characterized in that it contains an aqueous suspension of nanocapsules comprising a polymeric shell and a lipid core containing an oily solvent, said nanocapsules being at least partially coated with lecithin. 2. Composition according to claim 1, characterized in that said homopolymer or copolymer of (meth) acrylamide is selected from the group consisting of: optionally crosslinked homopolymers of (meth) acrylamide optionally Nsubstituted; copolymers of (meth) acrylamide with at least one monomer chosen from acrylic acid, an alkyl (meth) acrylate, sodium acrylate, ammonium acrylate, dimethyl diallyl ammonium chloride, acrylonitrile, and vinylpyrrolidone; and optionally crosslinked copolymers of (meth) acrylamide Nsubstituted with an acrylamide monomer or an ethylenically unsaturated monomer optionally oxyalkylenated and having a hydrophobic group. 3. Composition according to Claim 2, characterized in that the N-substituted (meth) acrylamide homopolymers or copolymers are substituted with an optionally partially neutralized alkyl sulphonic acid. 4. Composition according to claim 3, characterized in that said N-substituted (meth) acrylamide homopolymer is a crosslinked polymer of 2-acrylamido-2-methyl propane sulfonic acid partially neutralized (AMPS). 5. Composition according to claim 3, characterized in that said copolymer of N-substituted (meth) acrylamide is an optionally crosslinked copolymer of 2acrylamido-2-methylpropanesulphonic acid and alkyl (meth) acrylate or alkyl (meth) ) optionally oxyalkylenated acrylamide, the alkyl group contains from 6 to 22 carbon atoms. <Desc / Clms Page number 24>  6. Composition according to claim 3, characterized in that said copolymer of (meth) acrylamide N-substituted is an optionally crosslinked copolymer of 2acrylamido-2-methylpropanesulfonic acid and acrylamide. 7. Composition according to any one of claims 1 to 6, characterized in that said polymeric shell comprises at least one polymer selected from poly-L-and DL-lactides and polycaprolactones, polyglycolides and their copolymers, polymers derived from the polymerization of alkyl cyanoacrylate (the alkyl chain having from 2 to 6 carbon); synthetic or natural hydrodispersible anionic polymers; polyesters of the poly (alkylene adipate) type; dendritic polymers; copolymers of vinyl chloride and vinyl acetate, copolymers of methacrylic acid and methacrylic acid methyl ester, polyvinyl acetophthalate, cellulose acetate phthalate, copolymers of polyvinylpyrrolidone crosslinked vinyl, polyethylenevinylacetates, polyacrylonitriles, polyacrylamides, polyethylene glycols, polyamides, polyethylenes, polypropylenes and organopolysiloxanes. 8. Composition according to Claim 7, characterized in that the said synthetic water-dispersible anionic polymers are chosen from: polyesters, poly (ester amides), polyurethanes and vinyl copolymers, all carrying carboxylic and / or sulphonic acid functions, and the natural hydrodispersible anionic polymers are selected from shellac resin, sandarac gum and dammars. 9. Composition according to claim 8, characterized in that said synthetic water-dispersible anionic polymers are chosen from copolyesters comprising at least units derived from isophthalic acid, sulfo-aryldicarboxylic acid and diethylene glycol. 10. Composition according to claim 7, characterized in that said poly (alkylene adipate) is a poly (ethylene adipate) with a weight average molar mass of about 10,000. <Desc / Clms Page number 25> 11. Composition according to claim 7, characterized in that said dendritic polymer is a dendritic polyester of generation 3 obtained by polycondensation of dimethylolpropionic acid on polyoxyethylenated pentaerythritol (on average 5 units of ethylene oxide on each hydroxyl function), of which 50% of the hydroxyl functions are esterified with C 8 acids. and in particular capric and caprylic acids. 12. Composition according to claim 7, characterized in that said polymer is polycaprolactone. 13. Composition according to any one of claims 1 to 12, characterized in that said lecithin is selected from hydrogenated or non-hydrogenated lecithins, natural or synthetic. 14. Composition according to claim 13, characterized in that said lecithin is soy lecithin containing at least 45% by weight of phosphatidylcholine. 15. Composition according to any one of claims 1 to 14, characterized in that said nanocapsules contain at least one active agent selected from vitamins and their fat-soluble derivatives, DHEA (dehydroepiandrosterone) and its derivatives, and ceramides. 16. Composition according to claim 15, characterized in that said active ingredient is chosen

 among: the retina) and its esters, in particular palmitate and retinyl caprylate; liposoluble ascorbic acid derivatives, in particular ascorbyl palmitate; tocopherol and its esters, in particular tocopheryl acetate; vitamin F; vitamin K; 3-alkanoyl 7-hydroxy-DHEA, 3-alkanoyl-7-alkanoyloxy-DHEA, 7-hydroxy-DHEA; ceramides of type 11, in particular 2-oleamido-1,3-octadecanediol; ceramides type t! Type V ceramides, in particular hydroxypalmitoyl sphinganine, and mixtures thereof. 17. Use according to any one of the preceding claims, characterized in that said composition also contains at least one soothing agent. <Desc / Clms Page number 26>

18. Use according to claim 17, characterized in that said soothing agent is chosen from: pentacyclic triterpenes, such as ss-glycyrrhetinic acid and its salts and / or its derivatives, ursolic acid and its salts, the acid oleanolic acid and its salts, betulinic acid and its salts; extracts of Paeonia suffruticosa and / or lactiflora, Rosmarinus officinalis, willowherb, Pygeum, Boswellia serrata, Centipeda cunnighami, Helianthus annuus, Cola nitida, clove and Bacopa moniera; salts of salicylic acid and in particular zinc salicylate; algae extracts, in particular Laminaria saccharina; Canola oil, Tamanu oil, Calophillum oil, unsaturated omega 3 oils such as rose hip, blackcurrant, ecchium, fish oil; a-bisabolol and chamomile extracts; allantoin the diesterphosphoric vitamin E and C; capryloyl glycine; tocotrienols; the piperonal; the aloe vera ; phytosterols; cortisone, hydrocortisone, indometacine

 beta methasone; a strain of Vitreoscilla filiformis, an aqueous extract of iris pallida and a hydroglycolic extract of Rosa gallic petals. 19. Cosmetic use of the composition as defined above for the care of sensitive skin. 20. Use of an aqueous suspension of nanocapsules comprising a polymeric envelope and a lipid core containing an oily solvent, said nanocapsules being at least partially coated with lecithin, to prevent or reduce irritation or feelings of discomfort due to a composition comprising at least one homopolymer or copolymer of (meth) acrylamide in a physiologically acceptable medium.