FR2903012A1 - Cosmetic use of polymer containing 2,2,6,6-tetramethyl piperidine-1-N-oxyl monomer to prevent and/or treat skin disorder e.g. skin aging, wrinkle, line, chloasma, skin-elasticity, solar erythema, actinic lentigo and skin-hyperpigmentation - Google Patents

Abstract

Cosmetic use of a polymer containing 2,2,6,6-tetramethyl piperidine-1-N-oxyl monomer to prevent and/or treat skin disorder partially induce by free radicals. An independent claim is included for a composition comprising the polymer and a photo-protecting agent. ACTIVITY : Dermatological; Muscular-Gen.; Antiinflammatory. MECHANISM OF ACTION : None given.

Description

1 Use of a polynitroxide to fight against skin disorders

  The present invention relates to the cosmetic use, for preventing and / or treating at least one skin disorder at least partially induced by free radicals, of at least one polymer containing at least one monomer bearing a radical 2,2. , 6,6-tetramethyl piperidine-1N-oxyl (TEMPO).

  It also relates to the use of this polymer for the preparation of a dermatological composition, and to a composition containing this polymer in combination with a photoprotective agent. Over time, there are various signs on the skin, very characteristic of aging, resulting in particular in a change in structure and cutaneous functions.

This aging, physiological in nature, may be accelerated by environmental factors such as repeated exposure of the skin to sunlight, and especially ultraviolet radiation A, to pollution, particularly to diesel particles or to cigarette smoke. The action of the environment on the constituents of the skin (fibers, cells, enzymes) and on the sebum secreted by the skin leads in particular to the formation of oxygen free radicals. However, these radicals cause significant oxidative damage, in particular in cell membranes (membrane permeability), cell nuclei (destruction of DNA), and tissues, in particular connective tissue (fiber degradation 2903012 2 d elastin and collagen). This damage leads in particular to a loss of firmness and elasticity of the skin.

It has further been suggested that free radicals may be involved in the process of making melanin leading to skin pigmentation. The mechanism of formation of melanin is particularly complex and schematically involves the following main steps Tyrosine ---> Dopa ---> Dopaquinone ---> Dopachrome ---> Melanin.

Tyrosinase (monophenol dihydroxyl phenylalanine, oxygen oxido-reductase EC 1.14.18.1) is the essential enzyme involved in this sequence of reactions. In particular, it catalyzes the conversion reaction of tyrosine to Dopa (dihydroxyphenylalanine) by virtue of its hydroxylase activity. However, some authors believe that the hydroxylation step of tyrosine into Dopa could be initiated by free radicals (C. Montastier et al., Methods of objectifying the effects of depigmenting agents in humans, J. Med. Esth and Chir Derm, Vol XXII, 86, June 1995, pp. 93-103). Free radicals formed under the influence of environmental factors could therefore lead to an increase in the formation of melanin, and cause or accentuate certain undesirable hyperpigmentations such as idiopathic melasmas, occurring during pregnancy ("pregnancy mask" or chloasma ) or estrogen-progestative contraception or localized hyperpigmentation 3, such as senile pigmentary spots known as actinic lentigo. Moreover, it is known that free radicals are also generated in certain pathologies where they act as mediators of inflammation, and in particular, in the case of acne, by neutrophils, these free radicals involved in the inflammatory process leading to the formation of pimples.

The production of all these free radicals can be increased in various situations and in particular in subjects who smoke or drink alcohol, or as a result of taking certain drugs.

It is therefore clear that free radicals generated either by environmental factors or endogenously, especially during inflammatory processes, are responsible for various aesthetic disorders, on the one hand, and pathological, on the other hand. It is therefore necessary to protect the body and in particular the skin against these free radicals.

This protective function is normally provided by enzymes present in the cutaneous tissue. However, under certain circumstances, the activity of these enzymes is not sufficient to completely block the destructive action of free radicals.

It has therefore been proposed to use various natural or synthetic products as cosmetic active agents to combat the damage caused by free radicals. Among these, mention may be made in particular of: free radical scavenging compounds such as vitamin C, vitamin E and their derivatives, as well as carotenoids; and compounds that stimulate free radical-blocking enzymes, such as phosphorus-rich compounds and trace elements.

It has further been proposed in EP-0 665 003 to use the anti-radical effect of certain nitroxides, such as tetramethyl piperidine oxide (TPO or TEMPO), encapsulated in a dispersion of spherules, to combat against the signs of aging, acne and UV damage. Other nitroxides of aromatic structure have also been described in application US 2003/0224026. These nitroxides of the prior art have several disadvantages. First, their small size makes them better able to penetrate the skin than compounds with higher steric hindrance. As a result, they can cause undesirable reactions within the epidermis or even the dermis, possibly causing tissue damage. In addition, the compounds described in US 2003/0224026 are difficult to synthesize since their method of preparation, as described in Tetrahedron, 31: 1745 (1975), involves many steps. The Applicant has now discovered, surprisingly, that certain polymers with a nitroxyl function have anti-radical properties which make it possible to envisage their topical application to the skin or the lips, for both cosmetic and therapeutic purposes. .

These polymers are particularly useful as anti-radical agents in solar products, as they form on the surface of the skin complementary free radical protection to the effect of UV filters. In addition, their lack of reactivity with the compounds other than free radicals ensures the chemical stability of the compositions, in particular cosmetics, containing them.

Some of these polymers are already known as catalysts for the selective oxidation of primary and secondary aliphatic and benzyl alcohols to aldehydes and ketones (Dijksman A. et al., Chem Commun 2000, 271-272). However, it has not yet been suggested to use them as free radical scavengers in cosmetic or pharmaceutical compositions for topical application to the skin or the lips. The present invention therefore relates to the cosmetic use, for preventing and / or treating at least one skin disorder at least partially induced by free radicals, of at least one polymer containing at least one monomer carrying a function 2.2 , 6,6-tetramethylpiperidine-1-N-oxyl (TEMPO).

The free radicals at the origin of the aforementioned disorders can be generated by UV and / or atmospheric pollution. These disorders include in particular the signs of cutaneous aging, in particular the formation of wrinkles and / or fine lines and the loss of firmness and / or elasticity of the skin, as well as cutaneous hyperpigmentation such as actinic lentigines (or senile spots) or chloasma (pregnancy mask). The invention also relates to the use of at least one polymer containing at least one monomer carrying a tetramethylpiperidine N-oxyl radical (TEMPO) for the manufacture of a pharmaceutical composition intended to be applied topically to the skin or the lips to prevent and / or treat at least one disorder related to free radicals.

It is understood that in this description, the term "topical" should be understood as meaning capable of exerting its effects on its application site, as opposed to, in particular, systemic. The targeted disorder may be an inflammatory component skin disorder, particularly selected from acne and solar erythema.

It also relates to a cosmetic process for preventing and / or treating at least one skin disorder at least partially induced by free radicals, comprising the topical application to the skin or the lips of a composition containing, in a physiologically acceptable medium, at least one polymer containing at least one monomer carrying a tetramethyl piperidine N-oxyl function (TEMPO).

The polymer used according to the invention is capable of being obtained from the corresponding secondary polyamine, which is generally a HALS-type polyamine (Hindered Amine Light Stabilizer or amine light stabilizer). sterically hindered), according to a process comprising for example the following steps: solubilization of the secondary polyamine with an organic solvent immiscible with water, such as dichloromethane, the addition of water to obtain a biphasic medium, addition to the biphasic medium, with vigorous stirring: (a) an aliphatic peracid, for example acetic acid peracid, in a molar ratio peracid / secondary amine preferably ranging from 1.5 to 2.5 and (b) in a sufficient amount of a basic aqueous solution, such as a potassium carbonate solution, to obtain a pH of the aqueous phase of biphasic medium ranging from 4 to 12, the temperature of this stage being preferred preferably between -10 ° C. and + 40 ° C., the recovery of the organic phase, advantageously by decantation, and the removal of the organic solvent, for example by evaporation under reduced pressure. Alternatively, the polymer according to the invention can be prepared as described in US Pat. No. 5,654,434, by reacting the starting polyamine with an aqueous solution of hydrogen peroxide at 80-99 ° C.

The secondary polyamine starting material may be commercially available, in which case the polymer according to the invention also has the advantage of being simple and inexpensive to manufacture, or it may itself be obtained by a synthetic process. . According to a preferred embodiment of the invention, the secondary polyamine used in the above process contains at least one monomer containing an N (2,2,6,6) -tetraalkyl-4-piperidinyl-2-amino group. 1,3,5-triazine. More specifically, it is preferred that this polyamine meets the formula (IV). wherein: z represents an integer from 2 to 20; R3 represents a hydrogen atom; X represents an oxygen atom or a group -NR4-; R 4 represents, simultaneously or independently, a hydrogen atom, a 2,2,6,6-tetramethyl-4-piperidinyl group or a linear, branched or cyclic, saturated or unsaturated C 1 -C 15 hydrocarbon group, said group A hydrocarbon containing one or two oxygen or nitrogen atoms, or two R4 groups, bonded to the same nitrogen atom, may be bonded together to form a 5- to 7-membered heterocycle which may contain a hydrogen atom. oxygen; R5 represents, simultaneously or independently, a hydrogen atom or a group -NR62- or both R5 are each NRaRb where Ra is a group (2,2,6,6) -tetramethyl-4-piperidinyl and the two substituents Rb together form a triazine group substituted with a group -NR42; R 6 represents, simultaneously or independently, a hydrogen atom, a linear, branched or cyclic, saturated or unsaturated C 1 -C 20 hydrocarbon group, a 2,2,6,6-tetramethyl-4-piperidinyl group or a group of the formula: wherein R7 is, simultaneously or independently, a hydrogen atom, a linear or branched C1-C12 alkyl group or a 2,2,6,6-tetramethyl-4-piperidinyl group; ; and Y represents, simultaneously or independently, a linear, branched or cyclic C1-C20 alkylene group which may comprise one or two oxygen or nitrogen atoms. According to a particularly preferred embodiment of the invention, the secondary polyamine has the formula (IV ') below: (V) embedded image in which: z represents an integer ranging from 2-10; m represents an integer from 2 to 12; R3 is a hydrogen atom; R4 represents, simultaneously or independently, a hydrogen atom, a 2,2,6,6-tetramethyl-4-piperidinyl group or a linear or branched C1-C10 alkyl or alkenyl group, or two R4 groups, linked to the same nitrogen atom may be bonded together to form a 6-membered heterocyclic ring which may contain an oxygen atom; and R 8 represents, simultaneously or independently, a hydrogen atom, a 2,2,6,6-tetramethyl-4-piperidinyl group or a linear or branched C 1 -C 10 alkyl or alkenyl group, or a group of formula (V) as defined above, or two R8 groups together form a triazine group substituted with a group -NR42-.

Most preferably, the polyamine has the formula (IV ') wherein m is 6; one of R4 is hydrogen and the other is tC8-H17; and R8 is a hydrogen atom. Such a polyamine having a number-average molecular weight of about 3000 is especially commercially available from CIBA under the trade name CHIMASSORB 944. Alternatively, the polyamine used according to the invention corresponds to formula (IV ') in which: m is 6; one of R4 is C4H9 and the other is 2,2,6,6-tetramethyl-piperidinyl; and R8 is a hydrogen atom.

According to another possibility, the polyamine used according to the invention corresponds to the formula (IV ') in which: m is 6; the R 4 groups together form a saturated six-membered heterocyclic ring containing an oxygen atom; and R8 is a hydrogen atom.

These compounds, identified by references 27, 28 and 29 in the publication of Kirchhoff J. et al., Polymers & Polymer Composites, Vol. 8, No. 4, 2000, are commercially available from DEGUSSA-HÜLS.

According to another possibility, the polyamine used according to the invention corresponds to the formula (IV ') in which: m is 6; the two R8 groups together form a triazine group substituted with a group -NR42-; and all R 4 groups together form a saturated six membered heterocycle containing an oxygen atom. According to another possibility, the polyamine used according to the invention corresponds to the formula (IV ') in which: m is 6; one of R4 is hydrogen and the other is 1,1-dimethyl-3,3-dimethylbutyl; and the two R8 groups together form a triazine group substituted with a group -NR42- where one of the R4 groups is a hydrogen atom and the other is a 1,1-dimethyl-3,3-dimethyl group butyl. Polyamines of this type are especially described in the application WO 02/058844 and one is commercially available from CIBA under the trade name CHIMASSORB 966. The implementation of the method described above on the polyamine CHIMASSORB 944 makes it possible to obtain the polymer described in Example 4 of application WO 00/40550, having a number-average molecular weight ranging from 2000 to 3100. This polymer, known under the designation PIPO (for polyamine immobilized piperidinyl oxyl 15 or immobilized polyamine-based piperidinyl oxide), identified by the CAS number 91993-31-6, is in particular commercially available from ARKEMA under the trademark OXYNITROX 5100.

It is in the form of an orange powder and thus offers the additional advantage of allowing a composition to be obtained that dyes the skin slightly and thus gives it a good-looking effect. This coloration is also advantageous in the case where the composition is a solar product, insofar as it can make it possible to clearly visualize the homogeneous application of the product on the skin. Alternatively, the starting polyamine may be a homopolymer of R9-Si (O) -RloO-M wherein R9, R10 are C1-C10alkyl and C1-C16alkylene, respectively, and M is group (2, 2, 6, 6) - tetramethylpiperidinyl. A compound of this type, where R9 is a methyl group and Rio is a propylene group, described as a compound in Kirchhoff J. et al., Polymers & Polymer Composites, Vol. 8, No. 4, 2000, is commercially available from DEGUSSA-HOLS.

Other polyamines of this type are available from GREAT LAKES under the trade names UVASIL 299LM, UVASIL 299HM and UVASIL 2000-2000LM.

As a further variant, the polymer used according to the invention may be a poly (2,2,6,6-tetramethylpiperidinyloxyl methacrylate) or PTMA, which may be manufactured as described in the publication by Nakahara K. et al., Chemical Physics Letters 359 (2002) 351-354.

The anti-radical properties of the polymer used according to the invention make it particularly suitable for use in cosmetic skin care compositions and especially in anti-aging and / or depigmenting compositions and / or in day creams or moisturizing, and in solar compositions. It is preferred that these compositions contain from 0.001 to 5% by weight of the polymer according to the invention, based on the total weight of the composition. The composition carrying this polymer also advantageously comprises at least one active agent chosen from: depigmenting agents or propigmenting agents, that is to say having respectively an effect of inhibition or activation of melanogenesis; anti-wrinkle and / or firming agents, such as compounds increasing the synthesis of collagen, elastin and / or proteoglycans or preventing their degradation, agents increasing the synthesis of anchoring proteins such as laminin, anti-glycation agents, or else dermo-decontracting agents or muscle relaxants; desquamating agents, such as keratinocyte differentiating enhancers or keratolytic active agents; self-tanning agents; anti-inflammatory or soothing agents; other anti-radical agents or anti-oxidants; and their mixtures.

Examples of depigmenting agents include the following compounds: kojic acid; ellagic acid; arbutin and its derivatives such as those described in EP-895,779 and EP-524,109; hydroquinone; resorcinol derivatives such as n-butyl resorcinol; aminophenol derivatives such as those described in applications WO 99/10318 and WO 99/32077, and in particular N-cholesteryloxycarbonyl-para-aminophenol and N-ethyloxycarbonyl-para-aminophenol; L-2-oxothiazolidine-4-carboxylic acid or procysteine, as well as its salts and esters; ascorbic acid and its derivatives, especially ascorbyl glucoside and ascorbyl phosphate salts; plant extracts, in particular narcissus, licorice, mulberry and skullcap; and their mixtures, without this list being limiting.

Examples of propigmenting agents include, in particular, plant extracts selected from. Caesapinia sappan, Primameria laevigata, Piper cubeba, Sonchus arvensis, Pluchea indica L., Massoia aromatica, Alstonia scholars, Alyciareindwartii BI., Cinnamomum sintoc, Arctostaphylos, Chenopodium, Poterium, Gautheria, Sanguisorba officinalis and Chrysanthemum and mixtures thereof.

The desquamating agent may be selected from: α-hydroxy acids such as citric, lactic, glycolic, mandelic, malic and tartaric acids; (3-hydroxyacids and in particular salicylic acid and its derivatives such as n-octanoyl-5-salicylic acid, α-ketoacids and (3-ketoacids, retinoids and in particular retinol and the esters of retinyl such as retinyl palmitate, HMG-CoA reductase inhibitors, lupine extracts, sugar derivatives such as 0-octanoyl-6 '- (3-D-maltose, and mixtures thereof. anti-wrinkle and / or firming agents include: ascorbic acid and its derivatives, retinol and its esters, oligopeptides and their acylated derivatives, in particular BIOPEPTIDE CL and MATRIXYL 3000 products marketed by SEDERMA; α-hydroxyacids, such as those mentioned above, saponins and sapogenins, extracts of Commiphora mukul, Centella asiatica, Pisum sativum, Saccharomyces cerevisiae and Macrocystis pyrifera, extracts of soy protein, resveratrol and its glycols. ycosides; magnesium or manganese salts and in particular gluconates; and their mixtures.

Examples of self-tanning agents include dihydroxyacetone (DHA) and erythrulose.

Examples of anti-inflammatory or soothing agents include: bisabolol, allantoin, aloe vera and mixtures thereof.

Examples of antiradical or antioxidant agents include, in addition to the polymer used according to the invention: olive leaf and olive leaf extracts; tocopherol and its esters such as tocopheryl acetate; extracts of green tea, rosemary or 10 plants containing carotenoids; ubiquinone or coenzyme Q10; and their mixtures. The composition according to the invention is, as indicated above, preferably adapted for topical application to the skin or the lips. It may be in any of the galenical forms normally used for this type of application, in particular in the form of an oil solution, an oil-in-water or oil-in-oil emulsion or a multiple emulsion, a silicone emulsion, or a microemulsion or nanoemulsion, an oily gel or a liquid, pasty or solid anhydrous product. According to a preferred embodiment, the composition according to the invention contains a continuous aqueous phase.

This composition may be more or less fluid and have the appearance of a cream, an ointment, a milk, a lotion, a paste, a mousse or a gel. It can optionally be applied to the skin in the form of an aerosol. It can also be in solid form, and for example in the form of a stick. It may alternatively be impregnated on a wipe. In known manner, the composition of the invention may also contain adjuvants usual in the cosmetic and dermatological fields, such as oils, waxes, hydrophilic or lipophilic gelling agents, surfactants, preservatives, perfumes, fillers. , Sequestering agents, dyestuffs. The amounts of these various adjuvants are those conventionally used in the fields under consideration, for example from 0.1 to 20% of the total weight of the composition. These adjuvants, depending on their nature, may be introduced into the fatty phase or into the aqueous phase. These adjuvants, as well as their concentrations, must be such that they do not adversely affect the advantageous properties of the polymer used according to the invention.

In a particularly preferred manner, this composition also contains one or more photoprotective agent (s). The present invention thus also relates to a composition containing, in a physiologically acceptable medium: (a) at least one polymer containing at least one monomer bearing a tetramethylpiperidine N-oxyl radical (TEMPO), and (b) at least one The present invention relates in particular to a composition containing, in addition to the polymer described above, at least one photoprotective agent or active filter in the UVA and / or UVB, of organic or inorganic nature.

Examples of organic filters suitable for use in this invention include, but are not limited to, organic filters. (1) benzophenone derivatives, benzophenones 3 and 5 being preferred; (2) triazine derivatives, and especially 2,4-bis {[4- (2-ethylhexyloxy) -2-hydroxy] -phenyl} -6- (4-methoxy-phenyl) -1, 3,5-triazine available from CIBA under the trade name TINOSORB S and 2,2'-methylenebis- [6- (2H benzotriazol-2-yl) 4- (1,1,3,3-tetramethylbutyl) phenol] available from CIBA under the trademark TINOSORB M; (3) terephthalylidene dicamphersulfonic acid or benzene 1,4 [di (3-methylidenecamphos-10-sulfonic acid)] or one of its alkali or alkaline earth metal, ammonium or organic base salts ; (4) salicylic acid derivatives, especially homomenthyl salicylate and octyl salicylate; (5) cinnamic acid derivatives, in particular 2-ethylhexyl p-methoxycinnamate, available from GIVAUDAN under the trademark Parsol MCX; (6) derivatives of liquid (3, (3'-diphenylacrylate, in particular 1-cyano- (3, p'-diphenylacrylate of 2-ethylhexyl, or octocrylene, available from the company BASF under the trade name UVINUL N539; (7) p-aminobenzoic acid derivatives; (8) 4-methyl benzylidene camphor available from MERCK under the tradename EUSOLEX 6300; (9) 2-phenylbenzimidazole acid; sulfonic acid sold under the trade name Eusolex 232 by the company Merck, (10) 1,3,5-triazine derivatives, in particular 2,4,6-tris [p- (2'-ethylhexyl) -1- oxycarbonyl) anilino] -1,3,5-triazine, available from BASF under the trade name UVINUL T150, and the compound available from SIGMA 3V under the trade name UVASORB HEB; benzotriazole silicones, such as that described in application FR-A-2 642 968, and (12) their mixtures. Inorganic photoprotective agents usable in the composition according to the invention are metal oxides and in particular those chosen from titanium oxides and zinc oxides, optionally coated, having an average particle size of between 5 and 100 nm. preferably between 10 nm and 50 nm. Typical coating agents are alumina and / or aluminum stearate. The invention will be better understood in the light of the examples given below for purely illustrative and in no way limiting. EXAMPLES The following compositions are prepared in a manner conventional to those skilled in the art. All quantities are indicated in percentages by weight. Example 1: Sun Lotion 30 Phase A Demineralized water qs 100.00% Magnesium sulphate 0.70% Glycerin 5.00% 2903012 Phase B Methylglucose isostearate 3.50% Copolymer PEG45 / dodecyl glycol 1.00% Laurate hexyl ester 11.00% Cetaneyl isononanoate 5.00% Diethylhexylcyclohexane 10.00% Silicon emulsifier 3.00% Candelilla wax 0.50% OXYNITROX S100 0.10% Preservatives 1.50% PVP / Eicosene copolymer 1.00 % Phase C Modified Hectorite 1.50% Phase D 15 Zinc Oxide 2.50% Phase E Coated Titanium Oxide2 14.00% 1 ABILSOFT AF100 from GOLDSCHMIDT 20 2 Z HP1 LASERSON 3 KOBO IN60S4 from ISP Example 2: Cream day 25 Phase A Demineralised water qs 100.00% Glycerin 27.00% Butylene glycol 13.50% Sodium chloride 1.00% 30 Phase B Silicone emulsifier4 9.00% Silicone elastomer5 1.00% Silicone oils 13 , 50% 2903012 5 21 OXYNITROX SI00 0.50% 3 DC 5225C from DOW CORNING 4 DC 9040 from DOW CORNING 10

Claims (22)

  1. Cosmetic use, for preventing and / or treating at least one skin disorder at least partially induced by free radicals, of at least one polymer containing at least one monomer bearing a 2,2,6,6-tetramethylpiperidine radical 1-N-oxyl (TEMPO).   2. Use according to claim 1, characterized in that the free radicals are generated by UV and / or atmospheric pollution.   3. Use according to claim 1 or 2, characterized in that the skin disorder is a sign of skin aging.   4. Use according to claim 3, characterized in that the sign of skin aging is chosen from: the formation of wrinkles and / or fine lines and the loss of firmness and / or elasticity of the skin.   5. Use according to claim 1 or 2, characterized in that the skin disorder is cutaneous hyperpigmentation.   6. Use according to claim 5, characterized in that the cutaneous hyperpigmentation is an actinic lentigo or a chloasma. 30   7. Use of at least one polymer containing at least one N-oxyl tetramethyl piperidine radical (TEMPO) monomer for the manufacture of a pharmaceutical composition for topical application to the skin or the lips to prevent and treat or treat at least one free radical related disorder.   8. Use according to claim 7, characterized in that the disorder is a skin disorder with an inflammatory component.   9. Use according to claim 8, characterized in that the skin disorder is selected from acne and solar erythema.   10. Use according to any one of claims 7 to 9, characterized in that the polymer is obtainable from a secondary polyamine according to a process comprising the following steps: solubilization of the secondary polyamine with a water-immiscible organic solvent, the addition of water to obtain a biphasic medium, the addition to biphasic medium, with vigorous stirring: (a) an aliphatic peracid and (b) a sufficient amount of a basic aqueous solution, to obtain a pH of the aqueous phase of biphasic medium ranging from 4 to 12, the recovery of the organic phase, and the removal of the organic solvent.   11. Use according to claim 10, characterized in that the polyamine contains at least one monomer containing an N- (2,2,6,6) -tetraalkyl-4-piperidinyl-2-amino-1,3,5 group. triazine. 2903012 24   12. Use according to claim 11, characterized in that the polyamine corresponds to the formula (IV): in which: z represents an integer ranging from 2 to 20; R3 represents a hydrogen atom; X represents an oxygen atom or a group -NR4-; R 4 represents, simultaneously or independently, a hydrogen atom, a 2,2,6,6-tetramethyl-4-piperidinyl group or a linear, branched or cyclic, saturated or unsaturated C 1 -C 15 hydrocarbon-based group, said hydrocarbon group may contain one or two oxygen or nitrogen atoms, or two R4 groups, bonded to the same nitrogen atom, may be bonded together to form a 5- to 7-membered heterocycle which may contain an oxygen atom; R5 represents, simultaneously or independently, a hydrogen atom or a group -NR62-; R6 represents, simultaneously or independently, a hydrogen atom, a linear, branched or cyclic, saturated or unsaturated C1-C20 hydrocarbon group, a 2,2,6,6-tetramethyl-4-piperidinyl group or a group of the formula: (V) wherein R7 represents, simultaneously or independently, a hydrogen atom, a linear or branched C1-C12 alkyl group or a 2,2,6,6-tetramethyl-4-piperidinyl group; and Y represents, simultaneously or independently, a linear, branched or cyclic C 1 -C 20 alkylene group which may comprise one or two oxygen or nitrogen atoms. 10   13. Use according to claim 12, characterized in that the polyamine has the formula (IV ') below: R7 ~ s R7 R3> .ääN ~ Y Nù (CH2) m Re' yNù (CH2) m R3 N ,, .. <. Wherein Z represents an integer from 2 to 10; m represents an integer from 2 to 12; R3 is a hydrogen atom; R4 represents, simultaneously or independently, a hydrogen atom, a 2,2,6,6-tetramethyl-4-piperidinyl group or a linear or branched C1-C10 alkyl or alkenyl group, or two linked R4 groups; at the same nitrogen atom, may be bonded together to form a 6-membered heterocyclic ring which may contain an oxygen atom; and R 8 represents, simultaneously or independently, a hydrogen atom, a 2,2,6,6-tetramethyl-4-piperidinyl group or a linear or branched C 1 -C 10 alkyl or alkenyl group or a group of formula ( V) as defined above, or two R8 groups together form a triazine group substituted with -NR42-.   14. Use according to claim 13, characterized in that the polyamine corresponds to the formula (IV ') in which: m is 6; one of R4 is hydrogen and the other is tC8-H17; and R8 is a hydrogen atom.   15. A composition comprising, in a physiologically acceptable medium: (a) at least one polymer containing at least one monomer carrying a tetramethylpiperidine N-oxyl radical (TEMPO), and (b) at least one photoprotective agent.   16. Composition according to claim 15, characterized in that the photoprotective agent is an organic UV filter. 2903012 27   17. Composition according to claim 16, characterized in that the UV filter is chosen from: (1) benzophenone derivatives; (2) triazine derivatives, and especially 2,4-bis {[4- (2-ethylhexyloxy) -2-hydroxy] -phenyl} -6- (4-methoxy-phenyl) -1, 3,5-triazine and 2,2'-methylenebis- [6- (2H benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol]; (3) terephthalylidene dicamphersulfonic acid or benzene 1,4 [di (3-methylidenecamphos-10-sulfonic acid)] 10 or one of its alkali or alkaline earth metal, ammonium or an organic base salts ; (4) salicylic acid derivatives, especially homomenthyl salicylate and octyl salicylate; (5) cinnamic acid derivatives, particularly 2-ethylhexyl p-methoxycinnamate; (6) liquid (3,3 '-3'-diphenylacrylate derivatives, especially 2-ethylhexyl-3-cyano- (3'-p-diphenylacrylate, or octocrylene, (7) p-acid derivatives; (8) 4-methyl benzylidene camphor, (9) 2-phenylbenzimidazole 5-sulfonic acid, (10) 1,3,5-triazine derivatives, in particular 2,4,6-tris [p- (2'-ethylhexyl-1-oxycarbonyl) anilino] -1,3,5-triazine, (11) benzotriazole silicones, and (12) mixtures thereof.   18. Composition according to claim 15, characterized in that the photoprotective agent is an inorganic photoprotective agent chosen from metal oxides. 2903012 28   19. Composition according to claim 18, characterized in that the metal oxides are chosen from titanium oxides and zinc oxides, optionally coated, having an average particle size of between 5 and 100 nm.   20. A cosmetic process for preventing and / or treating at least one skin disorder at least partially induced by free radicals, comprising the topical application to the skin or the lips of a composition containing, in a physiologically acceptable medium, the at least one polymer containing at least one monomer bearing a tetramethylpiperidine N-oxyl radical (TEMPO). 15   21. The method of claim 20, characterized in that the polymer is as defined in any one of claims 10 to 14.   22. The process according to claim 1, characterized in that the composition is as defined in any one of claims 15 to 19.