USE OF AN ESTER DERIVED FROM 4-CARBOXY-2-PYRROLIDINONE AS A SOLVENT IN COSMETIC COMPOSITIONS; COSMETIC COMPOSITIONS CONTAINING SAME
The present invention relates to the use of at least one ester derived from 4-carboxy-2-pyrrolidinone, of formula (I), the definition of which will be given hereinafter, in a composition comprising, in a cosmetically acceptable medium, at least one liquid fatty phase and at least one lipophilic active agent, as a solvent for said active agent in said liquid fatty phase and/or as an agent for improving the solubility of said active agent in the solid fatty phase.
The present invention relates in particular to a composition comprising, in a cosmetically acceptable medium, at least one liquid fatty phase characterized in that it contains at least one ester derived from 4-carboxy-2-pyrrolidinone, of formula (I), and at least one lipophilic active agent.
Many cosmetic or dermatological products are provided in various galenical forms comprising a liquid fatty phase, such as dispersions, oily lotions, oil/water, water/oil or multiple emulsions, or cream gels. Certain particularly advantageous cosmetic or dermatological active agents, such as lipophilic organic screening agents, are not readily soluble in the oily phase of these formulations and have a tendency during storage to form crystals or to precipitate, in particular in emulsions. Such phenomena
are undesirable from the point of view of stability of the formulation and/or with respect to consumer comfort insofar as they can destabilize the composition and/or affect the aesthetic appearance of the product and/or lead to cosmetic discomfort upon application to the skin and/or the hair, or else to the concentration of active agents being limited in these formulations, which means that products that are sufficiently effective cannot be obtained.
This is especially the case of care formulations containing low-solubility lipophilic active agents, such as active agents chosen from aminophenol derivatives, salicylic acid derivatives, 2-amino-4-alkylaminopyrimidine 3-oxide derivatives, in particular 2-amino-4-dodecylaminopyrimidine 3-oxide, DHEA (dehydroepiandrosterone), its derivatives and its chemical precursors such as 7-hydroxy- or 7-keto-DHEA, or else 3ß-acetoxy-7-keto-DHEA, cholesterol and its esters, plant sterols such as phytosterols and sitosterols and their esters, pentacyclic triterpenic acids, hydroxystilbenes, flavonoids, lipophilic organic UV screening agents in anti-sun formulations, retinol and its derivatives, carotenoids such as lycopene, and also fragrances, essential oils, hormones, vitamins, in particular vitamin E, ceramides, or mixtures thereof.
In particular, anti-sun compositions are often in the form of an oil-in-water or water-in-oil emulsion,
of gels or of anhydrous products which contain, at various concentrations, one or more lipophilic and/or hydrophilic, insoluble and/or soluble, organic and/or inorganic screening agents capable of selectively absorbing harmful UV radiation. These screening agents and the amounts thereof are selected according to the desired protection factor. Depending on whether they are lipophilic or, conversely, hydrophilic in nature, these screening agents can be distributed, respectively, into the fatty phase or into the aqueous phase of the final composition.
Lipophilic screening agents are commonly used in anti-sun formulations. However, for a certain number of them, their photoprotective capacity when formulated is quite limited in the usual cosmetic carriers containing oils, such as oxyethylenated or oxypropylenated fatty (mono/poly)alcohols ("Cetiol HE" from Henkel or "Witconol APM" from Witco) or else fatty esters such as C12-C15 alkyl benzoate ("Finsolv TN" from Finetex) , fatty acid triglycerides, for example Miglyol® 812 sold by the company Dynamit Nobel, or amino acid derivatives ("Eldew SL205" from Ajinomoto), the solubility of these screening agents in these oils commonly used in formulation not being completely satisfactory. The result of this is: either the appearance over time of crystallization in the formulations, which is detrimental to the good quality, stability and
effectiveness of the anti-sun products; or the fact that the concentration of screening agents in the formulations has to be limited, thereby making it impossible to obtain sufficiently effective products.
There exists therefore the need to find novel solvents for effectively dissolving lipophilic active agents and in particular lipophilic screening agents in order to improve their solubility in the oils and in the carriers of cosmetic or dermatological formulations containing them, without the drawbacks listed above.
Pyrrolidone derivatives are known as penetrating agents for active agents such as oleocanthal in application WO 2008/01240 or such as asprotadil alkyl esters in patent US 6 673 841.
Now, the applicant has just discovered, surprisingly, a new family of effective solvents constituted of esters derived from 4-carboxy-2-pyrrolidinone, of formula (I), the definition of which will be given hereinafter, which make it possible to achieve this objective. These compounds can be incorporated into many cosmetic products.
This discovery forms the basis of the present invention.
The present invention relates to the use of at least one ester derived from 4-carboxy-2-pyrrolidinone, of formula (I), the definition of which will be given hereinafter, in a composition comprising, in a
cosmetically acceptable medium, at least one liquid fatty phase and at least one lipophilic active agent, as a solvent for said active agent in said liquid fatty phase and/or as an agent for improving the solubility of said active agent in said fatty phase.
The present invention relates in particular to a composition comprising, in a cosmetically acceptable medium, at least one liquid fatty phase characterized in that it contains at least one ester derived from 4-carboxy-2-pyrrolidinone, of formula (I), and at least one lipophilic active agent.
The present invention also relates to the use of at least one derivative of formula (I) in a composition comprising, in a cosmetically acceptable medium, at least one liquid fatty phase and at least one lipophilic active agent, with the aim of improving the effectiveness of said active agent and/or the cosmetic qualities and/or the stability of said composition.
The present invention also relates to the use of at least one derivative of formula (I) in a composition comprising, in a cosmetically acceptable medium, at least one liquid fatty phase and at least one lipophilic organic UV screening agent, with the aim of improving the sun protection factor.
Other characteristics, aspects and advantages of the invention will become apparent upon reading the detailed description which follows.
The term "cosmetically acceptable" is intended to mean compatible with the skin and/or its appendages, which has a pleasant colour, odour and feel and which does not create any unacceptable discomfort (tingling, tautness, redness), that may dissuade the consumer from using this composition.
For the purpose of the present application, the term "liquid fatty phase" is intended to mean a fatty phase that is liquid at ambient temperature (25°C) and atmospheric pressure (760 mmHg), composed of one or more fatty substances that are liquid at ambient temperature, also known as oils, which are compatible with one another.
The term "lipophilic active agent" is intended to mean any cosmetic or dermatological organic active agent that can be completely dissolved in the molecular state in a liquid fatty phase, or else can be solubilized in colloidal form (for example in micellar form) in a liquid fatty phase.
The expression "low-solubility lipophilic active agent" is intended to mean any cosmetic or dermatological organic active agent having a solubility in water of less than 0.5% by weight and a solubility of less than 10% by weight in most organic solvents such as liquid paraffin, fatty alcohol benzoates and fatty acid triglycerides, for example Miglyol® 812 sold by the company Dynamit Nobel. This solubility, realized
at 70°C, is defined as the amount of product in solution in the solvent at equilibrium with an excess of solid in suspension after a return to ambient temperature. It can be readily evaluated in the laboratory.
The esters derived from 4-carboxy-2-pyrrolidinone in accordance with the invention are chosen from those corresponding to general formula (I) below:
(Formula Removed)
in which:
R1 denotes a linear or branched C1-C20 alkyl radical, R2 denotes a linear or branched C1-C20 alkyl radical that may contain a C5-C6 ring, the phenyl radical, the benzyl radical or the phenethyl radical.
In formula (I), among the alkyl groups, mention may in particular be made of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-octyl, 2-ethylhexyl, dodecyl, hexadecyl, cyclohexyl or methylcyclohexyl groups.
Among the compounds of formula (I), use will more particularly be made of the following products (a) to (oo) :

(Formula Removed)
Use will more particularly be made of the derivatives of examples (t), (u), (v), (x), (j), (1), (m) , (w) , (n) , (ab) , (ii) and (kk) .
The derivatives of formula (I) in accordance with the invention are preferably present in the compositions of the invention at contents ranging from 1% to 30% by weight, and more preferably from 3% to 20%
by weight, relative to the total weight of the composition.
The derivatives of formula (I), the syntheses of which are described in the following articles: J. Org. Chem., 26, pages 1519-24 (1961); Tetrahedron Asymmetric, 12 (23), pages 3241-9 (2001); J. Industrial & Engineering Chem., 47, pages 1572-8 (1955); J. Am. Chem. Soc, 60, pages 402-6 (1938); and in patents EP 0069512, US 2811496 (1955), US 2826588, US 3136620, FR 2290199 and FR 2696744, can be readily obtained:
- either by condensation of a diester of itaconic
acid of formula (II) with a primary amine of formula
(III), with or without solvent at a temperature between
20°C and 150°C according to the following scheme:
(Scheme Removed)
-or in two stages starting from the itaconic acid
of formula (IV) by condensation with the primary amine
of formula (III), in the presence or absence of a
solvent, so as to give the intermediate acid of formula
(V), followed by esterification of this acid of formula
(V) in the presence of an excess of alcohol of formula
(VI) according to the following scheme:
(Scheme Removed)
- or the derivatives of formula (I) comprising an ester chain R'1 (linear or branched C3-C20 alkyl radical) can also be obtained by transesterification of the derivatives comprising an ester chain R1 (methyl or ethyl radical) in the presence of a linear or branched C3-C20 alcohol and of a tin catalyst or titanium catalyst according to the following scheme:
(Scheme Removed)
According to one particular embodiment of the invention, the derivative(s) of formula (I) in accordance with the invention is (are) present in an amount sufficient to solubilize, by itself or by themselves (without it being necessary to use another solvent), the entire amount of lipophilic active agent(s) present in the composition.
According to another particular embodiment of the invention, the derivative(s) of formula (I) in
accordance with the invention constitute (s) the sole solvent for the lipophilic active agent (s).
In this case, the liquid fatty phase may be constituted of the derivative(s) of formula (I) and the lipophilic active agent (s) dissolved in said phase. Among the lipophilic active agents that can be used in accordance with the invention, lipophilic organic screening agents will be used. They can be chosen from para-aminobenzoic acid derivatives, salicylic derivatives, cinnamic derivatives, anthranilic derivatives, dibenzoylmethane derivatives, ß,ß-diphenylacrylate derivatives, benzylidenecamphor derivatives, phenylbenzimidazole derivatives, benzotriazole derivatives, imidazoline derivatives, benzalmalonate derivatives, 4,4-diarylbutadiene
derivatives, benzoxazole derivatives, malonitrile or
malonate diphenyl butadiene derivatives, chalcones, and
mixtures thereof.
Among the lipophilic UVA screening agents capable
of absorbing UV radiation from 320 to 400 nm, mention
may be made of:
dibenzoylmethane derivatives:
4-isopropyldibenzoylmethane, sold under the
name "Eusolex 8020" by the company Merck, and
corresponding to the formula below:
(Formula Removed)
1-(4-methoxy-l-benzofuran-5-yl)-3-phenylpropane-1,3-dione, sold by the company Quest under the name Pongamol, of formula:
(Formula Removed)
- 1-(4-tert-butylphenyl)-3-(2-hydroxyphenyl)propane-1,3-dione, of formula:
(Formula Removed)
butyl methoxydibenzoylmethane sold in particular under the trade name "Parsol 1789" by Hoffmann La Roche,
anthranilic derivatives:
Menthyl anthranilate, sold under the trade name "Neo Heliopan MA" by Haarmann and Reimer,
4,4-diarylbutadiene derivatives:
1, 1-dicarboxy(2,2'-dimethylpropyl)-4,4-diphenylbutadiene.
Those preferred are:
Among the lipophilic UVB screening agents, capable of absorbing UV radiation from 280 to 320 nm, mention
may be made of:
para-aminobenzoates:
Ethyl PABA
Ethyl dihydroxypropyl PABA
Ethylhexyl dimethyl PABA (Escalol 507 from ISP),
salicylic derivatives:
- Homosalate, sold under the name "Eusolex HMS" by Rona/EM Industries,
- Ethylhexyl salicylate, sold under the name "Neo Heliopan OS" by Haarmann and Reimer,
- Dipropylene glycol salicylate, sold under the name "Dipsal" by Scher,
- TEA salicylate, sold under the name "Neo Heliopan TS" by Haarmann and Reimer,
cinnamic derivatives:
Ethylhexyl methoxycinnamate, sold in particular under the trade name "Parsol MCX" by Hoffmann La Roche,
Isopropyl methoxycinnamate,
Isoamyl methoxycinnamate, sold under the trade name "Neo Heliopan E 1000" by Haarmann and Reimer,
Diisopropyl methylcinnamate,
Cinoxate,
Glyceryl ethylhexanoate dimethoxycinnamate,
(2E)-3-(2,4,5-trimethoxyphenyl)prop-2-enoic acid having the formula below:
(Formula Removed)
ß, ß ' -diphenylacrylate derivatives :
Octocrylene, sold in particular under the trade name "Uvinul N539" by BASF,
Etocrylene, sold in particular under the trade name "Uvinul N35" by BASF,
benzylidenecamphor derivatives:
3-Benzylidenecamphor, manufactured under the name "Mexoryl SD" by Chimex,
Methylbenzylidenecamphor, sold under the name "Eusolex 6300" by Merck,
Polyacrylamidomethyl benzylidenecamphor, manufactured under the name "Mexoryl SW" by Chimex,
imidazoline derivatives:
Ethylhexyl dimethoxybenzylidene dioxoimidazoline propionate,
benzalmalonate derivatives:
Polyorganosiloxanes comprising a benzalmalonate function, such as Polysilicone-15 sold under the trade name "Parsol SLX" by Hoffmann La Roche,
Dineopentyl 4'-methoxybenzalmalonate.
Among the broad-spectrum lipophilic screening agents capable of absorbing UVA and UVB radiation, mention may be made of:
Benzotriazole derivatives:
Drometrizole trisiloxane, sold under the name "Silatrizole" by Rhodia Chimie,
Bumetrizole, sold under the name "Tinoguard AS" by Ciba-Geigy.
Diphenyl butadiene derivatives:
The derivatives of the class of the malonitrile or malonate diphenyl butadienes are derivatives of general formula (VII) below:
(Formula Removed)
in which R3 represents a C1-C2 alkyl group or a C1-C2 alkoxy group and n is 0, 1 or 2; R4 and R5, which may be identical or different, represent -COOR6, -(C=O)NHR6, -(C=O)R6 or -CN, in which R6 represents a linear or branched alkyl group containing from 1 to 12 carbon atoms, and which may contain silane, siloxane or polysiloxane groups.
Among the malonitrile or malonate diphenyl butadiene derivatives, mention may in particular be made, without limitation, of:
- dimethyl 2-(3,3-diphenylprop-2-enylidene)malonate
- diisobutyl 2-(3,3-diphenylprop-2-enylidene)malonate
- bis(1,3-dimethylbutyl) 2-(3,3-diphenylprop-2-enyli-dene) malonate
- dineopentyl 2-(3,3-diphenylprop-2-enylidene)malonate
- methyl (2Z)-2-cyano-5,5-diphenylpenta-2,4-dienoate
-ethyl (trimethylsilyl)methyl (2Z)-2-(3,3-diphenyl-prop-2-enylidene)malonate
- (2E)-2-cyano-5,5-diphenyl-N-(3-{l,3,3,3-tetramethyl-
1-[(trimethylsilyl)oxy]disiloxanyl}propyl)penta-2,4-
dienamide
- ethyl 2-methyl-3-{1,3,3,3-tetramethyl-l-[(trimethylsilyl) oxy]disiloxanyl}propyl (2E)-2-(3,3-diphenylprop-2-enylidene)malonate
- ethyl (2Z)-5,5-diphenyl-2-{[(3-{1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl}propyl)amino]-carbonyl}penta-2,4-dienoate.
Among the diphenyl butadiene derivatives mentioned above, use will in particular be made of dineopentyl 2-(3,3-diphenylprop-2-enylidene)malonate corresponding to the formula below:
(Formula Removed)
It is known practice to use these diphenyl butadiene derivatives in anti-sun compositions; patent EP 0916335 describes carbon derivatives and also methods for obtaining them, and patents EP 1535947 and EP 1535925 describe siloxane and silane derivatives, respectively.
Chalcones:
The lipophilic screening agents of the chalcone class correspond to general formula (VIII) below:
(Formula Removed)
in which the R6 and R7 radicals denote, independently of one another, a hydrogen atom, the hydroxyl radical, a linear or branched C1-C12 alkyl or alkenyl group, a linear or branched C1-C12 alkoxy group or a linear or branched C2-C20 acyloxy group; p and q
Among the chalcone derivatives, mention may in particular be made, without limitation, of:
- 2'-hydroxychalcone
- 4'-hydroxychalcone
- 4'-methoxychalcone
- 2'-hydroxy-4-methoxychalcone
- 2'-hydroxy-4-hexyloxychalcone
- 2'-hydroxy-4-methylchalcone
- 2'-hydroxy-3-hexyloxychalcone
- 2'-hydroxy-4'-hexyloxy-4-methylchalcone
- 2'-hydroxy-4'-hexanoyloxy-4-methoxychalcone
- 2',4',4-trihydroxy-3,3'-diallylchalcone (known as Kazonol)
- 2',4',4-trihydroxy-5'-(3-methylbut-2-ene)chalcone (known as Broussochalcone B)
- 2',3',4',6',4-pentahydroxychalcone (known as Carthamin).
Among the chalcone derivatives mentioned above, use will in particular be made of 4'-hydroxychalcone corresponding to formula (Villa) below:
(Formula Removed)
or else 2',3',4' ,6',4-pentahydroxychalcone (known as Carthamin) corresponding to formula (VIIIb) below:
(Formula Removed)
It is known practice to use these chalcone compounds in anti-sun compositions, in particular in patents FR 2555167, FR 2602228 and FR 2608150.
The lipophilic screening agents are generally present in the compositions according to the invention in proportions ranging from 0.01% to 20% by weight, relative to the total weight of the composition, and preferably ranging from 0.1% to 10% by weight, relative to the total weight of the composition.
Among the screening agents of which the lipophilicity is difficult, mention may, for example, be made of dibenzoylmethane derivatives, benzotriazole derivatives, chalcones, and derivatives of the class of
malonitrile or malonate diphenyl butadienes.
The term "low-solubility lipophilic screening agent" is intended to mean any cosmetic or dermatological organic active agent which has a solubility in water of less than 0.5% by weight and a solubility of less than 10% by weight in most organic solvents such as liquid paraffin, fatty alcohol benzoates and fatty acid triglycerides, for example Miglyol® 812 sold by the company Dynamit Nobel. This solubility, realized at 70°C, is defined as the amount of product in solution in the solvent at equilibrium with an excess of solid in suspension after a return to ambient temperature. It can be readily evaluated in the laboratory.
The low-solubility lipophilic active agents in
accordance with the invention may also be chosen from
aminophenol derivatives, salicylic acid derivatives,
N,N'-di(arylmethylene)ethylenediaminetriacetate
derivatives, 2-amino-4-alkylaminopyrimidine 3-oxide
derivatives, flavonoids, retinol and its derivatives,
carotenoids such as lycopene, and also fragrances,
essential oils, hormones, vitamins, in particular
vitamin E, ceramides, or mixtures thereof.
The aminophenol derivatives used are more
particularly the derivatives of formula (IX) below:

(Formula Removed)
in which R' is a radical chosen from the group made up of the following radicals (a) , (b) and (c) :
(a) -CO-NR1R2
(b) -CO-O-R3
(c) -SO2R3
where R1 represents a hydrogen atom or an optionally
hydroxylated, saturated or unsaturated, linear or
branched C1 to C6 alkyl radical,
R2 represents a hydrogen atom or a radical chosen from
saturated or unsaturated, linear, cyclic or branched C12
to C30 alkyl radicals, which is optionally hydroxylated,
and
R3 represents a radical chosen from saturated or
unsaturated, linear, cyclic or branched, including
fused polycyclic, C12 to C30 alkyl radicals, which are
optionally hydroxylated.
In formula (IX), among the linear or branched R2 or R3 alkyl radicals containing from 1 to 30 carbon atoms, mention may advantageously be made of methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, hexyl, octyl, nonyl, 2-ethylhexyl, dodecyl, hexadecyl, behenyl, octadecyl and 2-butyloctyl radicals. Preferably, these radicals contain from 1 to 12 carbon atoms. Even more preferably, the alkyl radical generally contains from 1 to 6 carbon atoms. As a lower alkyl radical, mention may be made of methyl, ethyl, propyl, isopropyl, tert-butyl and hexyl radicals.
When it is unsaturated, a radical having one or more ethylenic unsaturations, such as more particularly the allyl radical, is preferred.
When the alkyl radical is cyclic, mention may in particular be made of the cyclohexyl, cholesteryl or tert-butylcyclohexyl radical.
When it is hydroxylated, the radical preferably contains from 1 to 6 carbon atoms and from 1 to 5 hydroxyl groups. Among monohydroxyalkyl radicals, a radical preferably containing 1 or 3 carbon atoms, in particular the hydroxymethyl, 2-hydroxyethyl, 2-hydroxypropyl or 3-hydroxypropyl radical, is preferred.
Among polyhydroxyalkyl radicals, a radical containing from 3 to 6 carbon atoms and from 2 to 5 hydroxyl groups, such as 2,3-dihydroxypropyl, 2,3, 4-trihydroxybutyl, 2,3,4,5-tetrahydroxypentyl and 2,3,4,5,6-pentahydroxyhexyl radicals, is preferred.
The alkoxylated radicals are alkyl radicals, as in particular described above, preceded by an oxygen atom.
Preferably, the aminophenol derivatives used in the present application are those for which at least one and preferably all of the conditions below are met:
- the -OH function on the phenyl radical is in the ortho-position or advantageously in the para-position,
- R' is chosen from a radical of formula (a) or (b).
Among the linear or branched alkyl radicals R1,
mention may be made of methyl, ethyl, propyl, isopropyl, tert-butyl or hexyl radicals.
The aminophenol derivative preferably used in said composition is a para-aminophenol derivative; even more preferably, it is N-ethoxycarbonyl-4-para-aminophenol of formula (IXa):
(Formula Removed)
or else N-cholesteryloxycarbonyl-4-para-aminophenol of formula (IXb):
(Formula Removed)
These aminophenol derivatives, and also the process for the preparation thereof, are described in patent applications WO 99/10318 and WO 99/32077.
These derivatives have a more or less long hydrocarbon-based chain, preferably alkoxycarbonyl chain, attached to the nitrogen atom. They have the drawback of being poorly soluble, or even not at all soluble, in water or in the fatty phase of the type used in the present application. Their introduction into cosmetic compositions requires, as regards the compounds with a short hydrocarbon-based chain, them to be solubilized in an aqueous-alcoholic solution, which is not always desirable when the composition is
intended, for example, to be applied around the eyes.
As for the compounds with a long hydrocarbon-based chain, they are insoluble in oils, owing to their steric bulk, and have a tendency to recrystallize from water.
The compositions according to the present invention comprising such an aminophenol derivative can be used as a depigmenting or bleaching agent in a cosmetic and/or dermatological composition.
The salicylic acid derivatives are the derivatives of formula (X) below:
(Formula Removed)
in which:
R"1 represents a hydroxyl radical or an ester of
formula -O-CO-R"4
in which R''4 is a saturated or unsaturated, aliphatic
radical containing from 1 to 26 carbon atoms,
preferably from 1 to 18 carbon atoms, or an amine or
thiol function optionally substituted with an alkyl
radical containing from 1 to 18 carbon atoms, and
preferably from 1 to 12 carbon atoms,
R''2 and R"3, independently of one another, are in the
3-, 4-, 5- or 6-position on the benzene ring and
represent, independently of one another, a hydrogen
atom or a radical: -(O)n-(CO)m-R"5
in which n and m, independently of one another, are each an integer equal to 0 or 1, provided that R"2 and R"3 are not simultaneously hydrogen atoms, and R"5 represents a hydrogen, a linear, branched or cyclized, saturated aliphatic radical containing from 1 to 18 carbon atoms, or an unsaturated radical containing from 3 to 18 carbon atoms, bearing one to nine conjugated or unconjugated double bonds, it being possible for the radicals to be substituted with at least one substituent chosen from halogen atoms (fluorine, chlorine, bromine, iodine), the following radicals: trifluoromethyl, hydroxyl in free form or esterified with an acid containing from 1 to 6 carbon atoms, or carboxyl in free form or esterified with a lower alcohol containing from 1 to 6 carbon atoms, or an aromatic radical containing from 6 to 10 carbon atoms.
Preferably, the salicylic acid derivative is such that R"5 represents a saturated aliphatic radical containing from 3 to 15 carbon atoms.
Preferably, the salicylic acid derivative is such that R"1 represents a hydroxyl radical.
Preferably, the salicylic acid derivative is such that R"5 is in the 5-position on the benzene ring and R"2 represents a hydrogen atom.
According to one preferred embodiment of the invention, the salicylic acid derivatives are
derivatives of 5-n-octanoylsalicylic acid, 5-n-decanoylsalicylic acid, 5-n-dodecanoylsalicylic acid, 5-n-octylsalicylic acid, 5-n-heptyloxysalicylic acid, 4-n-heptyloxysalicylic acid, 5-tert-octylsalicylic acid, 3-tert-butyl-5-methylsalicylic acid, 3-tert-butyl-6-methylsalicylic acid, 3,5-diisopropylsalicylic acid, 5-butoxysalicylic acid, 5-octyloxysalicylic acid, 5-propanoylsalicylic acid, 5-n-hexadecanoylsalicylic acid, 5-n-oleoylsalicylic acid, 5-benzoylsalicylic acid, monovalent and divalent salts thereof, and mixtures thereof.
Most particular preference is given to use of the 2-hydroxy-5-octanoylbenzoic acid available for sale under the trade name "Mexoryl SAB" by the company Chimex; it corresponds to formula (Xa) below:
(Formula Removed)
It is known practice to use salicylic acid derivatives in topical compositions, for example, as a keratolytic agent for treating acne or as an anti-ageing agent; patent applications FR-A-2 581 542 and EP-A-378 936 describe such derivatives.
The salicylic acid derivatives are highly advantageous in particular for preventing or repairing the principal manifestations of skin ageing, namely

fine lines and wrinkles, disruption of the "grain" of the skin, modification of the complexion of the skin and loss of firmness and of tonicity of the skin. However, the use of these derivatives poses a problem insofar as, when they are introduced without modification into topical compositions, they do not solubilize and remain in the crystalline state, rendering the use of the composition containing them ineffective for the treatment of the skin.
Generally, these derivatives are solubilized in lower alcohols, such as ethanol or isopropanol, or solvents such as octyldodecanol, certain glycols, or short-chain (less than C12) fatty alcohols. However, these lower alcohols have the drawback of drying out and irritating the skin; it is therefore preferable to avoid using them in body and/or facial care products. In addition, these solubilizing agents can only be introduced in small amounts otherwise they may impair the cosmetic qualities (drying out of the skin) and the stability of the compositions containing them.
The concentration of salicylic acid derivatives of the composition according to the present invention is preferably f rom 0.001% to 15% by weight, more preferably from 0.1% to 5% by weight, relative to the total weight of the composition. The amount of amino acid esters will depend on the amount of salicylic acid derivatives to be solubilized. It may be from 0.01% to
90% by weight, and preferably between 0.1% and 60% by weight, relative to the total weight of the composition.
The composition according to the invention comprising at least one salicylic derivative can be used as a cosmetic or dermatological composition, and in particular for caring for, protecting, cleansing and/or making up keratin materials of human beings (skin, lips, keratin fibres such as the hair and eyelashes), and in particular for combating the signs of skin ageing and/or for smoothing out facial and/or body skin and/or for treating wrinkles and fine lines of the skin and/or for stimulating the process of epidermal renewal and/or for depigmenting and bleaching the skin and/or for treating acne and/or for treating skin disorders.
These derivatives and also the process for the preparation thereof, are described in patent WO 94/11338.
The derivatives of the 2-amino-4-alkylamino-pyrimidine 3-oxide family are the derivatives of general formula (XI) below:
(Formula Removed)
in which R" '1 represents an alkyl group containing from 1 to 20 carbon atoms, and Z' represents a hydrogen
atom or an -OR'''2 radical in which R'''2 represents an alkyl group containing from 1 to 12 carbon atoms, and also its acylated forms or its addition salts with acids.
Preferably, R'''1 is chosen from the group made up of hexyl, heptyl, octyl, nonyl, decyl, undecyl and dodecyl radicals.
Preferably, R'''2 is chosen from the group made up of ethyl, propyl, butyl, pentyl and hexyl radicals.
Even more preferably, the compound is N- (2-amino-3-oxidopyrimidin-4-yl)-N'-dodecylurea of formula (XIa) below:
The derivatives of the 2-amino-4-alkylamino-pyrimidine 3-oxide family may in particular be used in or for the preparation of a cosmetic or dermatological composition in accordance with the present invention for preventing and treating problems associated with sensitive skin and skin disturbances such as skin discomfort, tautness of the skin, skin itching, skin swelling, redness of the skin and heat sensation of the skin.
Another family of molecules which comes under the definition of molecules with low water-solubility is DHEA, derivatives thereof and chemical or metabolic precursors thereof.
DHEA, or dehydroepiandrosterone, also known as 3-beta-hydroxyandrost-5-en-17-one, or dehydroiso-androsterone, but also trans-dehydroandrosterone or prasterone, has the formula:
(Formula Removed)
The expression "DHEA precursors to which the invention relates" is intended to mean its biological precursors which are capable of being converted to DHEA during metabolism, and also its chemical precursors which can be converted to DHEA by exogenous chemical reaction.
Examples of biological precursors are A5-pregnenolone, 17α-hydroxypregnenolone and 17α-hydroxypregnenolone sulphate, without this list being limiting.
The expression "chemical precursors of DHEA" is intended to mean in particular saponins and their derivatives such as hecogenin ( (3beta, 5alpha, 23r)-3-hydroxyspirostan-12-one) and hecogenin acetate, diosgenin (5-spirosten-3-beta-ol), smilagenin and sarsapogenin, and also natural extracts containing them, in particular fenugreek and extracts of Dioscorea plants such as wild yam root, without this list being limiting.
The term "DHEA derivatives" is intended to mean both its metabolic derivatives and its chemical derivatives. As metabolic derivatives, mention may in particular be made of A5-androstene-3, 17-diol, and in particular 5-androstene-3[3,17(3-diol, A4-androstene-3,17-dione, 7-hydroxy-DHEA (7α-hydroxy-DHEA or 7(ß hydroxy-DHEA) and 7-keto-DHEA, which is itself a metabolite of 7(3-hydroxy-DHEA, without this list being limiting.
7α-Hydroxy-DHEA is, with 5-androstene-3ß, 17ß-diol, a major metabolite of DHEA, obtained by the action of 7α-hydroxylase on DHEA. 7ß-Hydroxy-DHEA is a minor metabolite of DHEA, obtained by the action of 7ß-hydroxylase on DHEA.
The 7-hydroxy-DHEA preferably used in the compositions according to the present invention is 7α-hydroxy-DHEA. A process for preparing this compound is described in patent applications FR 2 771 105 and WO 94/08588.
As chemical derivatives of DHEA, mention may also be made of DHEA salts, and in particular water-soluble salts such as DHEA sulphate; DHEA esters such as esters of hydrocarboxylic acids and of DHEA, in particular those described in patent US 5 736 537, or else DHEA salicylate, DHEA acetate, DHEA valerate (or n-heptanoate) and DHEA enanthate.
Mention may also be made of DHEA carbamates,
2-hydroxymalonate esters of DHEA and amino acid esters of DHEA. Finally, mention may be made of 3ß-acetoxy-7-oxo-DHEA which can in particular be prepared as described in patents US 5 869 709 and US 6 111 118. This list is obviously not limiting.
The concentration of DHEA-based compound in the composition according to the present invention can advantageously range from 0.001% to 30% by weight, preferably from 0.01% to 20%, and even more preferably from 0.01% to 10% by weight, relative to the total weight of the composition. These compounds will be in solubilized form between 20°C and 90°C.
According to a specific embodiment of the invention, the derivative(s) of formula (I) in accordance with the invention is (are) used as sole solvent for said lipophilic active agent(s).
The compositions in accordance with the invention may also comprise other organic UV screening agents that are active in the UVA range and/or the UVB range and that are water-soluble or else insoluble in the cosmetic solvents commonly used.
Among the water-soluble UVA screening agents capable of absorbing UV radiation from 320 to 400 nm, mention may be made of:
- terephthalylidene dicamphor sulphonic acid, manufactured under the name "Mexoryl SX" by Chimex,
- bisbenzoazolyl derivatives as described in patents
EP 669 323 and US 2 463 264, and more particularly the compound disodium phenyl dibenzimidazole tetrasulphonate, sold under the trade name "Neo Heliopan AP" by Haarmann and Reimer.
Among the water-soluble UVB screening agents capable of absorbing UV radiation from 280 to 320 nm, mention may be made of p-aminobenzoic acid (PABA) derivatives such as: PABA,
Glyceryl PABA, and
PEG-25 PABA, sold under the name "Uvinul P25" by BASF, Phenylbenzimidazole sulphonic acid, sold in particular under the trade name "Eusolex 232" by Merck, Ferulic acid, Salicylic acid, DEA methoxycinnamate,
Benzylidenecamphorsulphonic acid, manufactured under the name "Mexoryl SL" by Chimex,
Camphor benzalkonium methosulphate, manufactured under the name "Mexoryl SO" by Chimex, and
Among the water-soluble UVA and UVB screening agents, mention may be made of:
Benzophenone-4, sold under the trade name "Uvinul MS40" by BASF,
Benzophenone-5, and Benzophenone-9.
Among the insoluble screening agents, mention may
be made of:
- methylene bisbenzotriazolyl tetramethylbutylphenol, sold in solid form under the trade name "Mixxim BB/100" by Fairmount Chemical or in micronized form in aqueous dispersion under the trade name "Tinosorb M" by Ciba Specialty Chemicals,
- the symmetrical triazine screening agents described in patent US 6 225 467, patent application
WO 2004/085412 (see compounds 6 and 9) or the document "Symmetrical Triazine Derivatives", IP.COM Journal, IP.COM INC., West Henrietta, NY, US (20 September 2004), more particularly the 2, 4, 6-tris(biphenyl)-1,3,5-triazines (especially 2,4,6-tris (biphenyl-4-yl)-1,3,5-triazine) and 2,4,6-tris(terphenyl)-1,3,5-triazine, which is included in the Beiersdorf patent applications WO 06/035000, WO 06/034982, WO 06/034991, WO 06/035007, WO 2006/034992, WO 2006/034985.
Of course, those skilled in the art will take care to select the optional additional screening agent (s) and/or the amounts thereof in such a way that the advantageous properties intrinsically associated with the compositions in accordance with the invention are not, or are not substantially, impaired by the addition(s) envisaged.
The compositions according to the invention may also contain artificial tanning and/or browning agents for the skin (self-tanning agents) and more
particularly dihydroxyacetone (DHA). They are preferably present in amounts ranging from 0.1% to 10% by weight relative to the total weight of the composition.
The aqueous compositions conforming to the present invention may moreover comprise conventional cosmetic adjuvants in particular chosen from fatty substances, organic solvents, ionic or non-ionic, hydrophilic or lipophilic thickeners, demulcents, humectants, opacifiers, stabilizers, emollients, silicones, anti-foaming agents, fragrances, preservatives, anionic, cationic, non-ionic, zwitterionic or amphoteric surfactants, active agents, fillers, polymers, propellants and basifying or acidifying agents, or any other ingredient commonly used in the cosmetics and/or dermatological field.
The fatty substances may be composed of an oil or a wax other than the apolar waxes as defined previously, or mixtures thereof. The term "oil" is understood to mean a compound which is liquid at ambient temperature. The term "wax" is understood to mean a compound which is solid or substantially solid at ambient temperature, and of which the melting point is generally greater than 35°C.
As oils, mention may be made of mineral oils (paraffin); vegetable oils (sweet almond oil, macadaraia oil, blackcurrant seed oil, jojoba oil); synthetic oils

such as perhydrosqualene, alcohols, fatty amides (such as isopropyl lauroyl sarcosinate sold under the name "Eldew SL-205" by Ajinomoto), fatty acids or esters such as the benzoate of C12-C15 alcohols sold under the trade name "Finsolv TN" or "Witconol TN" by Witco, 2-ethylphenyl benzoate such as the commercial product sold under the name "X-Tend 226®" by ISP, octyl palmitate, isopropyl lanolate, triglycerides, including those of capric/caprylic acids, dicaprylyl carbonate sold under the name "Cetiol CC" by Cognis, oxyethylenated or oxypropylenated fatty esters and ethers; silicone oils (cyclomethicone, polydimethyl-siloxanes or PDMSs) or fluoro oils, and polyalkylenes.
As waxy compounds, mention may be made of carnauba wax, beeswax, hydrogenated castor oil, polyethylene waxes and polymethylene waxes such as that sold under the name "Cirebelle 303" by Sasol.
Among the organic solvents, mention may be made of lower polyols and alcohols. The lower polyols may be chosen from glycols and glycol ethers such as ethylene glycol, propylene glycol, butylene glycol, dipropylene glycol and diethylene glycol.
As hydrophilic thickeners, mention may be made of carboxyvinyl polymers such as carbopols (carbomers) and pemulens (acrylate/C10-C30 alkyl acrylate copolymers); polyacrylamides such as for example the crosslinked copolymers sold under the names "Sepigel 305" (CTFA
name: polyacrylamide/C13-14 isoparaffin/Laureth 7) or "Simulgel 600" (CTFA name: acrylamide/sodium acryloyl-dimethyltaurate copolymer/isohexadecane/polysorbate 80) by Seppic; polymers and copolymers of 2-acrylamido-2-methylpropanesulphonic acid optionally crosslinked and/or neutralized, such as poly(2-acrylamido-2-methylpropanesulphonic acid) sold by Hoechst under the trade name "Hostacerin AMPS" (CTFA name: ammonium polyacryloyldimethyl taurate) or "Simulgel 800" sold by Seppic (CTFA name: sodium polyacryloyldimethyl taurate/polysorbate 80/sorbitan oleate); copolymers of 2-acrylamido-2-methylpropanesulphonic acid and hydroxyethyl acrylate such as "Simulgel NS" and "Sepinov EMT 10" sold by Seppic; cellulose derivatives such as hydroxyethyl cellulose; polysaccharides and especially gums such as xanthan gum; and mixtures thereof.
As lipophilic thickeners, mention may be made of synthetic polymers such as poly (C10-C30 alkyl acrylates) sold under the name "Intelimer IPA 13-1" and "Intelimer IPA 13-6" by Landec or else modified clays such as hectorite and its derivatives, such as the products sold under the name "Bentone".
Among the active agents, mention may be made of:
- vitamins (C, K, PP, etc.) and derivatives or precursors thereof, alone or as mixtures;
- agents for combating pollution and/or free-radical
scavengers;
- depigmenting agents and/or propigmenting agents;
- anti-glycation agents;
- calmatives;
- NO-synthase inhibitors;
- agents for stimulating the synthesis of dermal or epidermal macromolecules and/or for preventing their degradation;
- agents for stimulating fibroblast proliferation;
- agents for stimulating keratinocyte proliferation;
- myorelaxants;
- tensioning agents;
- matting agents;
- keratolytic agents;
- desquamating agents;
- moisturizers;
- anti-inflammatory agents;
- agents that act on the energy metabolism of cells;
- insect repellents;
- substance P antagonists or CRGP antagonists;
- agents for preventing hair loss and/or for hair regrowth;
- anti-wrinkle agents.
Of course, those skilled in the art will take care to select the optional additional compound(s) mentioned above and/or the amounts thereof in such a way that the advantageous properties intrinsically associated with
the compositions in accordance with the invention are not, or are not substantially, impaired by the addition(s) envisaged.
The compositions according to the invention may be prepared according to the techniques well known to a person skilled in the art. They may be in particular in the form of a simple or complex (O/W, W/O, O/W/O or W/O/W) emulsion such as a cream, a milk or a cream-gel; in the form of an aqueous gel; or in the form of a lotion. They may also be packaged in an aerosol and be in the form of a foam or spray.
Preferably, the compositions according to the invention are in the form of an oil-in-water or water-in-oil emulsion.
The emulsions generally contain at least one emulsifier chosen from amphoteric, anionic, cationic or non-ionic emulsifiers, used alone or as a mixture. The emulsifiers are chosen in an appropriate manner according to the emulsion to be obtained (W/O or O/W). The emulsions may also contain other types of stabilizers such as for example fillers, gelling polymers or thickeners.
As emulsifying surfactants that can be used for preparing W/O emulsions, mention may be made, for example, of alkyl esters or ethers of sorbitan, of glycerol or of sugars; silicone surfactants, for example dimethicone copolyols, such as the mixture of
cyclomethicone and of dimethicone copolyol sold under the name "DC 5225 C" by Dow Corning, and alkyldimethicone copolyols such as laurylmethicone copolyol sold under the name "Dow Corning 5200 Formulation Aid" by Dow Corning; cetyl dimethicone copolyol such as the product sold under the name "Abil EM 90R" by Goldschmidt and the mixture of cetyl dimethicone copolyol, polyglycerol isostearate (4 mol) and hexyl laurate sold under the name "Abil WE 09" by Goldschmidt. It is possible to also add thereto one or more co-emulsifiers, which advantageously may be chosen from the group comprising alkylated polyol esters.
As alkylated polyol esters, mention may be made especially of polyethylene glycol esters, for example PEG-30 dipolyhydroxystearate such as the product sold under the name "Arlacel P135" by ICI.
As glycerol and/or sorbitan esters, mention may be made for example of polyglycerol isostearate, such as the product sold under the name "Isolan GI 34" by Goldschmidt; sorbitan isostearate, such as the product sold under the name "Arlacel 987" by ICI; sorbitan isostearate and glycerol such as the product sold under the name "Arlacel 986" by ICI, and mixtures thereof.
For the 0/W emulsions, mention may be made, for example as emulsifiers, of non-ionic emulsifiers such as oxyalkylenated (more particularly polyoxyethylenated) fatty acid and glycerol esters;
oxyalkylenated fatty acid and sorbitan esters; oxyalkylenated (oxyethylenated and/or oxypropylenated) fatty acid esters such as the PEG-100 stearate/glyceryl stearate mixture sold, for example, by ICI under the name "Arlacel 165"; oxyalkylenated (oxyethylenated and/or oxypropylenated) fatty alcohol ethers; sugar esters such as sucrose stearate; fatty alcohol and sugar ethers, especially alkylpolyglucosides (APGs) such as decyl glucoside and lauryl glucoside sold, for example, by Henkel under the respective names "Plantaren 2000" and "Plantaren 1200", cetostearyl glucoside, optionally as a mixture with cetostearyl alcohol, sold for example under the name "Montanov 68" by Seppic, under the name "Tegocare CG90" by Goldschmidt and under the name "Emulgade KE3302" by Henkel, and also arachidyl glucoside, for example in the form of the mixture of arachidyl and behenyl alcohols and arachidyl glucoside sold under the name "Montanov 202" by Seppic. According to one particular embodiment of the invention, the mixture of alkyl polyglucoside as defined above with the corresponding fatty alcohol may be in the form of a self-emulsifying composition, as described, for example, in document WO-A-92/06778.
Among the other emulsion stabilizers, use will more particularly be made of the polymers of isophthalic acid or sulphoisophthalic acid, and in
particular phthalate/sulphoisophthalate/glycol
copolymers, for example, the diethylene
glycol/phthalate/isophthalate/
1,4-cyclohexanedimethanol copolymer (INCI name:
Polyester-5) sold under the names "Eastman AQ polymer"
(AQ35S, AQ38S, AQ55S, AQ48 Ultra) by Eastman Chemical.
When an emulsion is involved, the aqueous phase of the latter may comprise a non-ionic vesicular dispersion prepared according to known processes (Bangham, Standish and Watkins, J. Mol. Biol. 13, 238 (1965), FR 2 315 991 and FR 2 416 008).
The compositions according to the invention find their application in a large number of treatments, in particular cosmetic treatments, for the skin, the lips and the hair, including the scalp, in particular for protecting and/or caring for the skin, the lips and/or the hair, and/or for making up the skin and/or the lips.
Another subject of the present invention is constituted of the use of the compositions according to the invention as defined above, for the manufacture of products for the cosmetic treatment of the skin, the lips, the nails, the hair, the eyelashes, the eyebrows and/or the scalp, in particular care products, anti-sun products and makeup products.
The cosmetic compositions according to the invention may, for example, be used as a makeup
product.
The cosmetic compositions according to the invention may, for example, be used as a care product and/or anti-sun product for the face and/or the body, of liquid to semi-liquid consistency, such as milks, more or less rich creams, gel creams, or pastes. They may optionally be packaged in an aerosol and may be in the form of a foam or a spray.
The compositions according to the invention in the form of vaporizable fluid lotions in accordance with the invention are applied to the skin or the hair in the form of fine particles using pressurized devices. The devices in accordance with the invention are well known to those skilled in the art and comprise non-aerosol pump-dispensers or "atomizers", aerosol containers comprising a propellant and also aerosol pump-dispensers that use compressed air as a propellant. The latter are described in patents US 4 077 441 and US 4 850 517.
The compositions packaged as an aerosol in accordance with the invention generally contain conventional propellants such as, for example, hydrofluoro compounds, dichlorodifluoromethane, difluoroethane, dimethyl ether, isobutane, n-butane, propane or trichlorofluoromethane. They are preferably present in amounts ranging from 15% to 50% by weight, relative to the total weight of the composition.
Concrete, but in no way limiting, examples that illustrate the invention will now be given.
SOLUBILITY OF LIPOPHILIC ACTIVE AGENTS, COMPARED BETWEEN PRIOR ART SOLVENTS AND THE SOLVENTS OF THE INVENTION
Active agents tested:
Active agent 1: ethyl 4-hydroxyphenylcarbamate
(Formula Removed)
Active agent 2: 2-hydroxy-5-octanoylbenzoic acid
(Formula Removed)
Active agent 3: N-(2-amino-3-oxidopyrimidin-4-yl)-N'-dodecylurea
(Formula Removed)
Screening agents tested
Screen 1: 1-(4-tert-butylphenyl)-3-(2-hydroxyphenyl)-propane-1,3-dione
(Formula Removed)
Screen 2: 1-(4-methoxy-l-benzofuran-5-yl)-3-phenyl-propane-1,3-dione
(Formula Removed)
Screen 3: 1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)-propane-1,3-dione (avobenzone) (known under the name "Parsol 1789" from DSM):
(Formula Removed)
Screen 4: 1- (4-isopropylphenyl)-3-phenylpropane-l,3-dione:
(Formula Removed)
Screen 5: dineopentyl 2-(3,3-diphenylprop-2-enylidene)-malonate:
Screen 6 : 2-(2H-1,2, 3-benzotriazol-2-yl)-4-methyl-6-(2-methyl-3-{l,3,3,3-tetramethyl-l-[(trimethylsilyl)-oxy]disiloxanyl}propyl)phenol:
(Formula Removed)
Screen 7 : (2E)-3-(2,4,5-trimethoxyphenyl)prop-2-enoic acid:
(Formula Removed)
Screen 8: (2E)-1-(4-hydroxyphenyl)-3-phenylprop-2-en-1-one:
Comparative oil 1: Eldew SL-205 from Ajinomoto: isopropyl N-lauroyl sarcosinate of formula:
(Formula Removed)
Comparative oil 2: Finsolv TN: C12-C15 alkyl benzoate
Comparative oil 3: Miglyol 812: caprylic/capric acid
triglycerides
Comparative oil 4: X-Tend: 2-phenylethyl benzoate
Procedure:
X mg of product are introduced into Y mg of oil; with mild heating (<60°C) and the use of a sonicator for 1 minute, the solution obtained is left at laboratory temperature for 1 month; the state of this solution is observed; if no crystal or oil deposit is visible, the solubility of the product is considered to be greater than XxlOO/(X+Y) weight/weight; when crystals or an oil deposit appear, the test is repeated with 5% less product.
Table 1 Table 2 Table 3

(Table Removed)
FORMULATION EXAMPLES 1-4
The following formulations were prepared, the amounts are expressed as percentages by weight relative to the total weight of the composition.
(Table Removed)
Procedure:
The aqueous phase (phase B) containing all its ingredients is heated to 80°C in a water bath. The fatty phase (phase A) containing all its ingredients is heated to 80°C in a water bath. A is emulsified in B with rotor-stator stirring (instrument from the company Moritz). Phase C is incorporated and the resulting mixture is left to return to ambient temperature with moderate stirring. The triethanolamine is introduced so as to adjust the pH to the desired value at the end of production. The anti-sun emulsions obtained are stable with respect to storage and do not display any crystals or precipitates.

CLAIMS
1. A process for preparing a pharmaceutical or cosmetic composition, which process comprises dissolving at least one lipohilic active agent in at least one liquid fatty phase, wherein said dissolution is effected in the presence of a 4-carboxy-2-pyrrolidinone of formula (I), or wherein the 4-carboxy-2-pyrrolidone of formula (I) is added after dissolution,
(Formula Removed)
in which:
R1 denotes a linear or branched C1-C20 alkyl radical,
R2 denotes a linear or branched C1-C20 alkyl radical that may
contain a C5-C6 ring, the phenyl radical, the benzyl radical
or the phenethyl radical.
2. A process according to Claim 1, in which the compounds of formula (I)are chosen from the following compounds (a) to (oo) :
(Formula Removed)
3. A process according to Claim 2, in which the compounds of formula (I) are chosen from the compounds (t), (u), (v), (x), (j), (1), (m), (w), (n), (ab), (ii) and (kk).
4. A process according to any one of Claims 1 to 3, in which the derivative(s) of formula (I) constitute said at least one liquid fatty phase, and constitute the sole solvent for the lipophilic active agent (s).
5. A process according to any one of Claims 1 to 4, in which the lipophilic active agent is chosen from lipophilic organic UV screening agents.
6. A process according to Claim 5, in which the lipophilic screening agent is chosen from para-aminobenzoic acid derivatives, salicylic derivatives, cinnamic derivatives, anthranilic derivatives, dibenzoylmethane derivatives,
ß,ß-diphenylacrylate derivatives, benzylidenecamphor derivatives,
phenylbenzimidazole derivatives, benzotriazole derivatives, imidazoline derivatives, benzalmalonate derivatives, 4,4-diarylbutadiene derivatives, benzoxazole derivatives, chalcones, malonitrile or malonate diphenyl butadiene derivatives, and mixtures thereof.

7. A process according to Claim 6, in which the lipophilic organic UV screening agents are chosen from dibenzoylmethane derivatives, benzotriazoles, chalcones, and malonitrile or malonate diphenyl butadiene derivatives.
8. A process according to any one of Claims 1 to 3, in which the lipophilic active agent is chosen from aminophenol derivatives, salicylic acid derivatives,
N,N'di(arylmethylene)ethylenediaminetriacetate derivatives, 2-amino-4-alkylaminopyrimidine 3-oxide derivatives, flavonoids, retinol and its derivatives, carotenoids such as lycopene, and also fragrances, essential oils, hormones, vitamins, in particular vitamin E, ceramides, or mixtures thereof.
9. Composition comprising, in a cosmetically acceptable medium, at least one liquid fatty phase characterized in that it contains at least one ester derived from 4-carboxy-2-pyrrolidinone, of formula (I), as defined in either one of Claims 1 and 2 and at least one lipophilic active agent.
10. Composition according to Claim 9, in which the lipophilic active agent is chosen from lipophilic organic UV screening agents.
11. Composition according to Claim 10, in which the lipophilic screening agent is chosen from para-aminobenzoic acid derivatives, salicylic derivatives, cinnamic derivatives, anthranilic derivatives,
dibenzoylmethane derivatives, ß,ß-diphenylacrylate derivatives, benzylidenecamphor derivatives, phenylbenzimidazole derivatives, benzotriazole derivatives, imidazoline derivatives, benzalmalonate derivatives, 4,4-diarylbutadiene derivatives, benzoxazole derivatives, chalcones, malonitrile or malonate diphenyl butadiene derivatives, and mixtures thereof.
12. Composition according to Claim 11, in which the lipophilic organic UV screening agent is chosen from benzotriazoles, chalcones, and malonitrile or malonate diphenyl butadiene derivatives.
13. Composition according to Claim 8, in which the lipophilic active agent is chosen from aminophenol derivatives, salicylic acid derivatives, N,N'-
di (arylmethylene)ethylenediaminetriacetate derivatives, 2-amino-4-alkylaminopyrimidine 3-oxide derivatives, flavonoids, retinol and its derivatives, carotenoids such as lycopene, and also fragrances, essential oils, hormones, vitamins, in particular vitamin E, ceramides, or mixtures thereof.
14. Composition according to any one of Claims 8 to 13, in which the derivative(s) of formula (I) in accordance with the invention is (are) preferably present in the compositions of the invention at contents ranging from 1% to 30% by weight, and more preferably from 3% to 20% by weight, relative to the
total weight of the composition.
15. Use of at least one derivative of formula (I)
as defined in either one of Claims 1 and 2, in a
composition comprising, in a cosmetically acceptable
medium, at least one liquid fatty phase and at least
one lipophilic active agent,- with the aim of improving
the effectiveness of said active agent and/or the
cosmetic qualities and/or the stability of said
composition.
16. Use of at least one derivative of formula (I)
as defined in either one of Claims 1 and 2, in a
composition comprising, in a cosmetically acceptable
medium, at least one liquid fatty phase and at least
one lipophilic organic UV screening agent, with the aim
of improving the sun protection factor.