COSMETIC COMPOSITION COMPRISING A DIBENZOYLMETHANE DERIVATIVE AND A 2-PYRROLIDINONE-4-CARBOXY ESTER COMPOUND; METHOD FOR THE PHOTOSTABILIZATION OF THE DIBENZOYLMETHANE DERIVATIVE
The present invention relates to a cosmetic composition comprising the combination of at least one screening agent of the dibenzoylmethane derivative type and at least one 2-pyrrolidinone-4-carboxy ester compound of formula (I), the definition of which will be given below.
It also relates to a process for the photostabilization, with regard to radiation, of at least one screening agent of the dibenzoylmethane derivative type by a specific 2-pyrrolidinone-4-carboxy ester compound of formula (I), the definition of which will be given below.
The present invention also relates to the use of at least one specific 2-pyrrolidinone-4-carboxy ester compound of formula (I) in a composition comprising, in a cosmetically acceptable vehicle, at least one dibenzoylmethane derivative for the purpose of improving the effectiveness of the said composition with regard to UV-A rays.
It is known that light radiation with wavelengths of between 280 nm and 400 nm makes possible browning of the human epidermis and that rays with wavelengths more particularly of between 280 and 320 nm, known under the name of UV-B, cause erythemas and skin burns which may be harmful to the development of natural tanning. For these reasons, and for aesthetic reasons, there exists a constant demand for means for controlling this natural tanning for the purpose of thus controlling the colour of the skin; it is thus advisable to screen out this UV-B radiation.
It is also known that UV-A rays, with wavelengths of between 320 and 400 nm, which cause browning of the skin, are capable of bringing about a detrimental change in the latter, in particular in the case of
sensitive skin or of skin continually exposed to solar radiation. UV-A rays cause in particular a loss in the elasticity of the skin and the appearance of wrinkles, resulting in premature skin ageing. They promote the triggering of the erythemal reaction or accentuate this reaction in some subjects and can even be the cause of phototoxic or photoallergic reactions. Thus, for aesthetic and cosmetic reasons, such as the preservation of the natural elasticity of the skin, for example, increasingly people desire to control the effect of UV-A rays on their skin. It is therefore desirable also to screen out UV-A radiation.
With the aim of providing protection of the skin and keratinous substances against UV radiation, use is generally made of antisun compositions comprising organic screening agents which are active in the UV-A region and which are active in the UV-B region. The majority of these screening agents are fat-soluble.
In this respect, a particularly advantageous family of UV-A screening agents is currently composed of dibenzoylmethane derivatives and in particular 4-tert-butyl-4'-methoxydibenzoylmethane, this being because these exhibit a high intrinsic absorption power. These dibenzoylmethane derivatives, which are now products well known per se as screening agents active in the UV-A region, are described in particular in French Patents FR-A 2 326 405 and FR-A 2 440 933, and in European Patent Application EP-A 0 114 607; furthermore, 4-tert-butyl-4'-methoxydibenzoylmethane is currently provided for sale under the trade name of "Parsol 1789 ®" by DSM Nutritional Products.
Unfortunately, it is found that dibenzoylmethane derivatives are products which are relatively sensitive to ultraviolet radiation (in particular UV-A radiation) , that is to say, more specifically, that they exhibit an unfortunate tendency to decompose more or less rapidly under the action of the latter. Thus, this substantial lack of photochemical stability of dibenzoylmethane derivatives in the face of the
ultraviolet radiation to which they are by nature intended to be subjected does not make it possible to guarantee continuous protection during prolonged exposure to the sun, so that repeated applications at regular and close intervals of time have to be carried out by the user in order to obtain effective protection of the skin against UV rays.
It is known that, in Patent EP 717 982, amide compounds have a photostabilizing effect on dibenzoylmethane derivatives and more particularly N,N-disubstituted amidated oils, such as the compound N,N-diethyl-3-methylbenzamide with the structure:
(Structure Removed)
or ethyl N-butyl-N-acetylaminopropionate of formula:
(Formula Removed)
such as the product sold under the trade name R3535 by the company Merck. These amidated oils have been described in particular in Application US2007141014 as solvents in cosmetic formulations of active principles which are difficult to dissolve in oils, such as UV screening agents, flavone derivatives, chromone derivatives, aryloximes and parabens.
However, this stabilization is obtained in the presence of 20 to 30% of the latter compound, which exhibits a high solvating power for all the starting materials involved in producing the formulations, the consequence of which is reflected by a destabilization of the compositions, rendering unsuitable for use the
compositions comprising such a combination.
Patent US 6 528 068 also discloses sun compositions comprising amidated oils which are neutral esters of N-acylamino acid comprising a linear or branched long-chain C6-C22 acyl group, such as Isopropyl Lauroyl Sarcosinate (Eldew SL 205 from Ajinomoto), in combination with organic UV screening agents which are difficult to dissolve in the oils commonly used in sun formulations. The combination of these amidated oils with a dibenzoylmethane derivative, such as 4-tert-butyl-4'-methoxydibenzoylmethane, does not make it possible to obtain a completely satisfactory dibenzoylmethane photostability.
The photostabilization of dibenzoylmethane derivatives with regard to UV radiation by amidated compounds thus constitutes, at the present time, a problem which has not yet been completely satisfactorily solved.
In point of fact, the Applicant Company has now just discovered, surprisingly, that, by combining the abovementioned dibenzoylmethane derivatives with a specific 2-pyrrolidinone-4-carboxy ester compound of formula (I) which will be defined in detail below, it is possible to further improve in a substantial and noteworthy way the photochemical stability (or photostability) of these same dibenzoylmethane derivatives and their effectiveness in the UV-A region. The compositions comprising such a combination also result, after application, in a more homogeneous distribution of the dibenzoylmethane screening agent.
This discovery forms the basis of the present invention.
Thus, in accordance with one of the subject-matters of the present invention, a composition is now provided comprising, in a cosmetically acceptable vehicle, at least one UV screening system, characterized in that it comprises:
(a) at least one dibenzoylmethane derivative and
(b) at least one 2-pyrrolidinone-4-carboxy ester
compound of formula (I), the definition of which will be given below.
Another subject-matter of the invention is also a method for improving the chemical stability with regard to UV radiation of at least one dibenzoylmethane derivative which consists in combining the said dibenzoylmethane derivative with an effective amount of at least one 2-pyrrolidinone-4-carboxy ester compound of formula (I), the definitions of which will be given below.
Another subject-matter of the present invention is the use of at least one 2-pyrrolidinone-4-carboxy ester compound of formula (I) in a composition comprising, in a cosmetically acceptable vehicle, at least one dibenzoylmethane derivative with the aim of improving the effectiveness of the said composition with regard to UV-A rays.
Other characteristics, aspects and advantages of the invention will become apparent on reading the detailed description which will follow.
"Cosmetically acceptable" is understood to mean compatible with the skin and/or its superficial body growths, exhibiting a pleasant colour, a pleasant odour and a pleasant feel, and not causing unacceptable discomfort (smarting, tightness, redness) liable to dissuade the consumer from using this composition.
"Effective amount" is understood to mean an amount sufficient to produce a notable and significant improvement in the photostability of the dibenzoylmethane derivative or derivatives in the cosmetic composition. This minimum amount of 2-pyrrolidinone-4-carboxy ester compound of formula (I) , which can vary according to the nature of the vehicle selected for the composition, can be determined without any difficulty by means of a conventional test for measuring photostability, such as that given in the examples below.
The 2-pyrrolidinone-4-carboxy ester compounds in accordance with the invention are chosen from those
corresponding to the following general formula (I):
(Formula Removed)
in which:
R1 denotes a linear or branched C1-C20 alkyl radical,
R2 denotes a linear or branched C1-C20 alkyl radical
which can comprise a C5-C6 ring, the phenyl radical, the
benzyl radical or the phenethyl radical.
In the formula (I), mention may in particular be made, among the alkyl groups, of the 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 (00) :

(Formula Removed)
Preference will more particularly be given to the compounds (j), (1), (m) and (n).
The derivatives of formula (I) , the syntheses of which are described in the following papers: 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 0 069 512, US 2 811 496 (1955), US 2 826 588, US 3 136 620, FR 2 290 199 and FR 2 696 744, can be easily obtained:
- either by the condensation of a diester of itaconic
acid of formula (II) with a primary amine of formula
(III), with or without solvent, at a temperature of
between 20°C and 150°C, according to the following scheme:
(Scheme Removed)
- or in 2 stages starting from itaconic acid of formula
(IV) by condensation with the primary amine of formula
(III) in or not in the presence of a solvent, in order
to give the intermediate acid of formula (V) , followed
by an 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)
The 2-pyrrolidinone-4-carboxy ester compounds of formula (I) in accordance with the invention are preferably present in the compositions at contents of 0.01 to 20% by weight and more preferably of 0.1 to 10% by weight, with respect to the total weight of the composition.
Mention may in particular be made, among the dibenzoylmethane derivatives, without implying a limitation, of:
- 2-methyldibenzoylmethane,
- 4-methyldibenzoylmethane,
- 4-isopropyldibenzoylmethane,
- 4-(tert-butyl)dibenzoylmethane,
- 2,4-dimethyldibenzoylmethane,
- 2,5-dimethyldibenzoylmethane,
- 4,4'-diisopropyldibenzoylmethane,
- 4,4'-dimethoxydibenzoylmethane,
- 4-(tert-butyl)-4'-methoxydibenzoylmethane,
- 2-methyl-5-isopropyl-4'-methoxydibenzoylmethane,
- 2-methyl-5-(tert-butyl)-4'-methoxydibenzoylmethane,
- 2,4-dimethyl-4'-methoxydibenzoylmethane,
- 2,6-dimethyl-4-(tert-butyl)-4' -methoxy
dibenzoylmethane .
Use will in particular be made, among the
abovementioned dibenzoylmethane derivatives, of 4-
isopropyldibenzoylmethane, sold under the name of
"Eusolex 8020" by Merck, which corresponds to the
following formula:
(Formula Removed)
Mention may also be made of 1-(4-methoxy-l-benzofuran-5-yl)-3-phenylpropane-l,3-dione, provided for sale by Quest under the name of Pongamol, of formula:
(Formula Removed)
Preference is very particularly given to the use of 4- (tert-butyl)-4'-methoxydibenzoylmethane or Butyl Methoxy Dibenzoylmethane, provided for sale under the trade name of "Parsol 1789" by DSM Nutritional Products; this screening agent corresponds to the following formula:
(Formula Removed)
The dibenzoylmethane derivative or derivatives can be present in the compositions in accordance with the invention at contents which preferably vary from 0.01 to 10% by weight and more preferably from 0.1 to 6% by weight, with respect to the total weight of the composition.
According to a particularly preferred form of the invention, use will additionally be made, in the compositions of the invention, of a silicated s-triazine compound substituted by two aminobenzoate or

aminobenzamide groups of following general formula (VI) or one of its tautomeric forms:
(Formula Removed)
in which:
- R, which are identical or different, represent a linear or branched C1-C30 alkyl radical which is optionally halogenated or unsaturated, a C6-C12 aryl radical, a C1-C10 alkoxy radical, a hydroxyl radical or the trimethylsilyloxy group;
- a = 0 to 3; in addition to the units of formula -A- (Si)(R) a (O)(3-a)/2, the organosiloxane can comprise units of formula: (R)b- (Si) (O)(4-b)/2, in which:
R has the same meaning as in the formula (II) and b = 1, 2 or 3;
the group (D) denotes an s-triazine compound of following formula (VII):
(Formula Removed)
where
X represents -O- or -NR3_, with R3 representing hydrogen or a C1-C5 alkyl radical,
- R1 represents a linear or branched C1-C30 alkyl radical
which is optionally unsaturated and which can comprise
a silicon atom, a C5-C20 cycloalkyl group, optionally
substituted by 1 to 3 linear or branched C1-C4 alkyl
radicals, the - (CH2CHR4-O) mR5 group or the
-CH2-CH(0H)-CH2-O-R6 group,
- R4 represents hydrogen or methyl; it being possible
for the (C=O)XR1 group to be in the ortho, meta or para
position with respect to the amino group,
- R5 represents hydrogen or a C1-C8 alkyl group,
- R6 represents hydrogen or a C4-C8 alkyl group,
- m is an integer ranging from 2 to 20,
- n1 = 0 to 2,
- R2, which are identical or different, represent a
hydroxyl radical, a linear or branched C1-C8 alkyl
radical or a C1-C8 alkoxy radical, it being possible for
two adjacent R2 groups on the same aromatic nucleus to
together form an alkylidenedioxy group in which the
alkylidene group comprises 1 or 2 carbon atoms,
A is a divalent radical chosen from methylene, -[CH (Si(CH3)3) ]-, ethylene or a group corresponding to one of the following formulae (VIII), (IX), (X) or (XI) :
(Formula Removed)
in which:
Z is a saturated or unsaturated and linear or branched C1-C10 alkylene diradical which is optionally substituted by a hydroxyl radical or oxygen atoms and which can optionally comprise an amino group, - W represents a hydrogen atom, a hydroxyl radical or a saturated or unsaturated and linear or branched C1-C8 alkyl radical.
It should be noted that the derivatives of formula
(VI) can be used in their tautomeric forms and more
particularly in the tautomeric form of following
formula (VI'):
(Formula Removed)
in which the group (D') denotes an s-triazine compound of following formula (VII'):
(Formula Removed)
The preferred s-triazine derivatives are those for which, in the formula (VII) or (VII'), at least one and more preferably still all of the following characteristics are met: R is methyl, a = 1 or 2, X is O,
R1 is a C4-C5 radical, n' = O,
the (C=O)XR1 group is in the para position with respect to the amino group, Z = -CH2-, W = H.
Preferably, the s-triazine compounds of the invention are represented by the following formulae (VIa), (VIb) and (VIc):
(Formula Removed)
in which:
(D) corresponds to the formula (VII) as defined above,
- R7, which are identical or different, are chosen from linear or branched C1-C20 alkyl, phenyl, 3,3,3-trifluoropropyl and trimethylsilyloxy radicals or the hydroxyl radical,
- R8, which are identical or different, are chosen from linear or branched C1-C20 alkyl and alkenyl radicals, hydroxyl radicals or phenyl radicals,
(B) , which are identical or different, are chosen from the R7 radicals and the (D) radical,
- r is an integer between 0 and 200 inclusive,
- s is an integer ranging from 0 to 50 and, if s = 0, at least one of the two (B) symbols denotes (D),
- u is an integer ranging from 1 to 10,
- t is an integer ranging from 0 to 10, it being
understood that t + u is equal to or greater than 3,
and their tautomeric forms.
The linear diorganosiloxanes of formula (VIa) are particularly preferred.
The linear or cyclic diorganosiloxanes of formula (VIa) or (VIb) coming within the scope of the present invention are random oligomers or polymers preferably exhibiting at least one or more preferably still all of the following characteristics:
- R7 is the methyl radical or the hydroxyl radical,
- B is preferably methyl (case of the linear compounds of formula (VIa)).
Mention will be made, as examples of particularly preferred compounds of formula (VI), of the compounds of following formulae (1) to (26) and their tautomeric

Use will more particularly be made of the compounds chosen from:
2,4-bis (ethyl 4'-aminobenzoate)-6-[ (3-{l,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl}-
(Formula Removed)
propyl)amino]-s-triazine of formula (2),
(Formula Removed)
2,4-bis(isopropyl 4'-aminobenzoate)-6-[ (3-{1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl}propyl)-amino]-s-triazine of formula (4)
(Formula Removed)
2,4-bis (n-butyl 4'-aminobenzoate)-6-[(3-{1, 3,3,3-tetramethyl-1-[(trimethylsilyl)oxy] -disiloxanyl}propyl)amino]-s-triazine of formula (5)
(Formula Removed)
2, 4-bis(isobutyl 4'-aminobenzoate)-6-[ (3-{1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl}propyl)-amino]-s-triazine of formula (6)
(Formula Removed)
2, 4-bis(neopentyl 4'-aminobenzoate)-6- [ (3-
{1,3,3,3-tetramethyl-l-[(trimethylsilyl)oxy]-disiloxanyl}propyl)amino]-s-triazine of formula (10)
(Formula Removed)
Use will more particularly still be made of 2,4-
bis(n-butyl 4'-aminobenzoate)-6-[(3-{l,3,3,3-tetra-methyl-1-[(trimethylsilyl)oxy]disiloxanyl}propyl)-amino]-s-triazine of formula (5):
(Formula Removed)
Some among the triazine compounds of formula (II) and their tautomeric forms are known and have been described in Patents EP 0 841 341 and FR 2 886 143.
The compositions according to the invention can additionally comprise other additional organic UV screening agents active in the UV-A and/or UV-B regions which are water-soluble or fat-soluble or else insoluble in the cosmetic solvents commonly used.
Of course, a person skilled in the art will take care to choose the optional additional screening agent or agents and/or their amounts so that the advantageous properties intrinsically attached to the compositions in accordance with the invention are not, or not substantially, detrimentally affected by the envisaged addition or additions, in particular the improvement in the photostability of the dibenzoylmethane derivative.
The additional organic screening agents are
chosen in particular from anthranilates; cinnamic
derivatives; salicylic derivatives; camphor
derivatives; benzophenone derivatives;
ß, ß-diphenylacrylate derivatives; triazine derivatives; benzotriazole derivatives; benzalmalonate derivatives, in particular those cited in Patent US 5
624 663; benzimidazole derivatives; imidazolines;
bis-benzoazolyl derivatives, such as described in
Patents EP 669 323 and US 2 463 264; p-aminobenzoic
acid (PABA) derivatives;
methylenebis(hydroxyphenylbenzotriazole) derivatives, such as described in Applications US 5 237 071, US 5 166 355, GB 2 303 549, DE 197 26 184 and EP 893 119; benzoxazole derivatives, such as described in Patent Applications EP 0 832 642, EP 1 027 883, EP 1 300 137 and DE 10162844; screening polymers and screening silicones, such as those described in particular in Application WO 93/04665; dimers derived from α-alkylstyrene, such as those described in Patent Application DE 19855649; 4,4-diarylbutadienes, such as described in Applications EP 0 967 200, DE 19746654, DE 19755649, EP-A-1 008 586, EP 1 133 980 and EP 133 981; merocyanine derivatives, such as those described in Applications WO04006878, WO05058269 and WO06032741; and their mixtures.
Mention may be made, as examples of additional organic photoprotective agents, of those denoted below under their INCI names: Cinnamic derivatives:
Ethylhexyl Methoxycinnamate, sold in particular under the trade name "Parsol MCX" by DSM Nutritional Products Inc., Isopropyl Methoxycinnamate,
Isoamyl Methoxycinnamate, sold under the trade name "Neo Heliopan E 1000" by Symrise, DEA Methoxycinnamate, Diisopropyl Methylcinnamate, Glyceryl Ethylhexanoate Dimethoxycinnamate,
para-Aminobenzoic acid derivatives:
PABA,
Ethyl PABA,
Ethyl Dihydroxypropyl PABA,
Ethylhexyl Dimethyl PABA, sold in particular under the
name "Escalol 507" by ISP,
Glyceryl PABA,
PEG-25 PABA, sold under the name "Uvinul P25" by BASF,
Salicylic derivatives:
Homosalate, sold under the name "Eusolex HMS" by
Rona/EM Industries,
Ethylhexyl Salicylate, sold under the name "Neo
Heliopan OS" by Symrise,
Dipropyleneglycol Salicylate, sold under the name
"Dipsal" by Scher,
TEA Salicylate, sold under the name "Neo Heliopan TS"
by Symrise,
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,
Benzophenone derivatives:
Benzophenone-1, sold under the trade name "Uvinul 400" by BASF,
Benzophenone-2, sold under the trade name "Uvinul D50" by BASF,
Benzophenone-3 or Oxybenzone, sold under the trade name "Uvinul M40" by BASF,
Benzophenone-4, sold under the trade name "Uvinul MS40" by BASF, Benzophenone-5,
Benzophenone-6, sold under the trade name "Helisorb 11" by Norquay,
Benzophenone-8, sold under the trade name "Spectra-Sorb UV-24" by American Cyanamid,
Benzophenone-9, sold under the trade name "Uvinul DS-4 9" by BASF, Benzophenone-12,
n-Hexyl 2-(4-diethylamino-2-hydroxybenzoyl)benzoate, sold under the trade name "Uvinul A+" by BASF,
Benzylidenecamphor derivatives:
3-Benzylidene camphor, manufactured under the name
"Mexoryl SD" by Chimex,
4-Methylbenzylidene camphor, sold under the name
"Eusolex 6300" by Merck,
Benzylidene Camphor Sulfonic Acid, manufactured under
the name "Mexoryl SL" by Chimex,
Camphor Benzalkonium Methosulfate, manufactured under
the name "Mexoryl SO" by Chimex,
Terephthalylidene Dicamphor Sulfonic Acid,
manufactured under the name "Mexoryl SX" by Chimex,
Polyacrylamidomethyl Benzylidene Camphor, manufactured
under the name "Mexoryl SW" by Chimex,
Phenylbenzimidazole derivatives:
Phenylbenzimidazole Sulfonic Acid, sold in particular
under the trade name "Eusolex 232" by Merck,
Disodium Phenyl Dibenzimidazole Tetrasulfonate, sold
under the trade name "Neo Heliopan AP" by Symrise,
Phenylbenzotriazole derivatives:
Drometrizole Trisiloxane, sold under the name
"Silatrizole" by Rhodia Chimie,
Methylene Bis-Benzotriazolyl Tetramethylbutylphenol,
sold in the solid form under the trade name "Mixxim
BB/100" by Fairmount Chemical or in the micronized
form in aqueous dispersion under the trade name
"Tinosorb M" by Ciba Specialty Chemicals,
Triazine derivatives:
Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, sold
under the trade name "Tinosorb S" by Ciba-Geigy,
Ethylhexyl Triazone, sold in particular under the
trade name "Uvinul T150" by BASF,
Diethylhexyl Butamido Triazone, sold under the trade
name "Uvasorb HEB" by Sigma 3V,
2,4,6-Tris(dineopentyl 4'-aminobenzalmalonate)-s-
triazine,
2,4,6-Tris(diisobutyl 4'-aminobenzalmalonate) -s-triazine,
2,4-Bis(dineopentyl 4'-aminobenzalmalonate)-6-(n-butyl 4'-aminobenzoate)-s-triazine,
The symmetrical triazine screening agents described in Patent US 6 225 467, 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), in particular 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 are taken up again in Patent Applications WO 06/035000, WO 06/034982, WO 06/034991, WO 06/035007, WO 2006/034992 and WO 2006/034985.
Anthranilic derivatives:
Menthyl anthranilate, sold under the trade name "Neo
Heliopan MA" by Symrise,
Imidazoline derivatives:
Ethylhexyl Dimethoxybenzylidene Dioxoimidazoline
Propionate,
Benzalmalonate derivatives:
Polyorganosiloxane comprising benzalmalonate functional groups, such as Polysilicone-15, sold under the trade name "Parsol SLX" by DSM Nutritional Products Inc.,
4,4-Diarylbutadiene derivatives:
1,1-Dicarboxy(2,2'-dimethylpropyl)-4,4-
diphenylbutadiene,
Benzoxazole derivatives:
2,4-bis[5-1(dimethylpropyl)benzoxazol-2-yl-(4-phenyl)imino]-6-(2-ethylhexyl)imino-1,3,5-triazine, sold under the name of Uvasorb K2A by Sigma 3V,
Merocyanine derivatives:
Octyl 5-N,N-diethylamino-2-phenylsulphonyl-2,4-
pentadienoate,
and their mixtures.
The preferred organic screening agents are chosen from:
Ethylhexyl Methoxycinnamate, Ethylhexyl Salicylate, Homosalate, Octocrylene,
Phenylbenzimidazole Sulfonic Acid, Benzophenone-3, Benzophenone-4, Benzophenone-5,
n-Hexyl 2-(4-diethylamino-2-hydroxybenzoyl)benzoate, 4-Methylbenzylidene Camphor, Terephthalylidene Dicamphor Sulfonic Acid, Disodium Phenyl Dibenzimidazole Tetrasulfonate, Methylene Bis-Benzotriazolyl Tetramethylbutylphenol, Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, Ethylhexyl Triazone, Diethylhexyl Butamido Triazone,
2,4,6-Tris (dineopentyl 4'-aminobenzalmalonate)-s-triazine,
2,4,6-Tris(diisobutyl 4'-aminobenzalmalonate)-s-triazine,
2,4-Bis (n-butyl 4'-aminobenzoate)-6-(aminopropyltri-siloxane)-s-triazine,
2,4-Bis(dineopentyl 4 ' -aminobenzalmalonate)-6-(n-butyl 4'-laminobenzoate)-s-triazine, 2,4,6-Tris(biphenyl-4-yl)-1,3,5-triazine, 2,4,6-Tris(terphenyl)-1,3,5-triazine, Drometrizole Trisiloxane, Polysilicone-15,
1,1-Dicarboxy(2,2'-dimethylpropyl)-4,4-diphenylbutadiene,
2,4-Bis[5-1(dimethylpropyl)benzoxazol-2-yl- (4-phenyl)imino]-6-(2-ethylhexyl)imino-1,3,5-triazine,

Octyl 5-N,N-diethylamino-2-phenylsulphonyl-2,4-
pentadienoate,
and their mixtures.
The additional organic screening agents in accordance with the invention generally represent from 0.1 to 30%, preferably from 1 to 25%, of the total weight of the composition.
Of course, a person skilled in the art will take care to choose the optional additional screening agent or agents and/or their amounts so that the advantageous properties intrinsically attached to the compositions in accordance with the invention are not, or not substantially, detrimentally affected by the envisaged addition or additions.
The compositions according to the invention can also comprise agents for the artificial tanning and/or browning of the skin (self-tanning agents) and more particularly dihydroxyacetone (DHA). They are preferably present in amounts ranging from 0.1 to 10% by weight, with respect to the total weight of the composition.
The aqueous compositions in accordance with the present invention can additionally comprise conventional cosmetic adjuvants chosen in particular from fatty substances, organic solvents, ionic or nonionic and hydrophilic or lipophilic thickeners, softening agents, humectants, opacifiers, stabilizing agents, emollients, silicones, antifoaming agents, fragrances, preservatives, anionic, cationic, nonionic, zwitterionic or amphoteric surfactants, active principles, fillers, polymers, propellants, basifying or acidifying agents or any other ingredient commonly used in the cosmetics and/or dermatological field.
Of course, a person skilled in the art will take care to choose the optional additive or additives and/or their amounts so that the advantageous properties intrinsically attached to the compositions in accordance with the invention are not, or not
substantially, detrimentally affected by the envisaged addition or additions.
The fatty substances can be composed of an oil or a wax, other than the nonpolar waxes as defined above, or their mixtures. 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 which has a melting point generally of greater than 35°C.
Mention may be made, as oils, of mineral oils (liquid paraffin); vegetable oils (sweet almond, macadamia, blackcurrant seed or jojoba oil); synthetic oils, such as perhydrosqualene, fatty alcohols, fatty amides (such as isopropyl lauroyl sarcosinate, sold under the name of "Eldew SL-205" by Ajinomoto), fatty acids or esters (such as C12-C15 alkyl benzoate, 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, or dicaprylyl carbonate, sold under the name "Cetiol CC" by Cognis), or oxyethylenated or oxypropylenated fatty esters and ethers; silicone oils (cyclomethicone, polydimethylsiloxanes or PDMSs); fluorinated oils; or polyalkylenes.
Mention may be made, as waxy compounds, of carnauba wax, beeswax, hydrogenated castor oil, polyethylene waxes and polymethylene waxes, such as that sold under the name Cirebelle 303 by Sasol.
Mention may be made, among organic solvents, of lower alcohols and polyols. The latter can be chosen from glycols and glycol ethers, such as ethylene glycol, propylene glycol, butylene glycol, dipropylene glycol or diethylene glycol.
Mention may be made, as hydrophilic thickeners, of carboxyvinyl polymers, such as the Carbopols (Carbomers) and the Pemulens (acrylate/C10-C30-alkyl
acrylate copolymer); 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 acryloyldimethyltaurate copolymer/ isohexadecane/polysorbate 80) by Seppic; optionally crosslinked and/or neutralized polymers and copolymers of 2-acrylamido-2-methylpropanesulphonic acid, such as the 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 of hydroxyethyl acrylate, such as Simulgel NS and Sepinov EMT 10, sold by Seppic; cellulose derivatives, such as hydroxyethylcellulose; polysaccharides and in particular gums, such as xanthan gum; and their mixtures.
Mention may be made, as lipophilic thickeners, of synthetic polymers, such as the poly(C10-C30 alkyl acrylates) sold under the names "Intelimer IPA 13-1" and "Intelimer IPA 13-6" by Landec, or of modified clays, such as hectorite and its derivatives, such as the products sold under the Bentone names.
Mention may be made, among active principles, of: vitamins (C, K, PP, and the like) and their derivatives or precursors, alone or as mixtures;
- agents for combating pollution and/or agents for
combating free radicals;
- depigmenting agents and/or propigmenting agents;
- antiglycation agents;
- soothing agents;
- NO-synthase inhibitors;
- agents which stimulate the synthesis of dermal or
epidermal macromolecules and/or which prevent their
decomposition;
agents which stimulate the proliferation of fibroblasts;
agents which stimulate the proliferation of keratinocytes;
- muscle-relaxing agents;
- tightening agents;
- matifying agents;
- keratolytic agents;
- desquamating agents;
- moisturizing agents;
- antiinflammatory agents;
- agents which act on the energy metabolism of the
cells;
- insect repellents;
- substance P or substance CRGP antagonists;
agents for combating hair loss and/or for the regrowth of the hair;
- antiwrinkle agents.
The compositions according to the invention can be prepared according to techniques well known to a person skilled in the art. They can in particular be provided in the form of a simple or complex (O/W, W/O, 0/W/O or W/O/W) emulsion, such as a cream or a milk, or of a cream gel; in the form of an aqueous gel; in the form of a lotion. They can optionally be packaged as an aerosol and be provided in the foam or spray form.
Preferably, the compositions according to the invention are provided in the form of an oil-in-water or water-in-oil emulsion.
The emulsions generally comprise at least one emulsifier chosen from amphoteric, anionic, cationic or nonionic emulsifiers, used alone or as a mixture. The emulsifiers are appropriately chosen according to the emulsion to be obtained (W/O or O/W emulsion). The emulsions can also comprise other types of stabilizing agents, such as, for example, fillers or gelling or thickening polymers.
Mention may be made, as emulsifying surfactants which can be used for the preparation of the W/0 emulsions, for example, of sorbitan, glycerol or sugar alkyl esters or ethers; silicone surfactants, such as dimethicone copolyols, for example the mixture of cyclomethicone and of dimethicone copolyol sold under the name "DC 5225 C" by Dow Corning, and alkyl dimethicone copolyols, such as lauryl methicone 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, of polyglycerol (4 mol) isostearate and of hexyl laurate sold under the name Abil WE 09 by Goldschmidt. It is also possible to add thereto one or more coemulsifiers which, advantageously, can be chosen from the group consisting of polyol alkyl esters.
Mention may in particular be made, as polyol alkyl esters, of polyethylene glycol esters, such as PEG-30 dipolyhydroxystearate, such as the product sold under the name Arlacel P135 by ICI.
Mention may be made, as esters of glycerol and/or of sorbitan, 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; glycerol sorbitan isostearate, such as the product sold under the name Arlacel 986 by ICI, and their mixtures.
Mention may be made, for the 0/W emulsions, for example, as emulsifiers, of nonionic emulsifiers, such as oxyalkylenated (more particularly polyoxyethylenated) esters of fatty acids and of glycerol; oxyalkylenated esters of fatty acids and of sorbitan; 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; ethers of fatty alcohol and of sugar, in particular alkyl polyglucosides (APG), such as decyl glucoside and lauryl glucoside, for example sold by Henkel under the respective names Plantaren 2000 and Plantaren 1200, cetearyl glucoside, optionally as a mixture with cetearyl alcohol, for example sold under the name Montanov 68 by Seppic, under the name Tegocare CG90 by Goldschmidt and under the name Emulgade KE3302 by Henkel, and arachidyl glucoside, for example in the form of the mixture of arachidyl and behenyl alcohols and of arachidyl glucoside sold under the name Montanov 202 by Seppic. According to a specific embodiment of the invention, the mixture of the alkyl polyglucoside as defined above with the corresponding fatty alcohol can be in the form of a self-emulsifying composition, for example as disclosed in the document WO-A-92/06778.
Use will more particularly be made, among other emulsion stabilizers, of polymers of isophthalic acid or sulphoisophthalic acid and in particular the phthalate/sulphoisophthalate/glycol copolymers, for example the diethyleneglycol/
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 can comprise a nonionic vesicular dispersion prepared according to known methods (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 have applications in a large number of treatments, in particular cosmetic treatments, of the skin, lips and hair, including the scalp, in particular for protecting and/or caring for the skin, lips and/or hair and/or for making up the skin and/or lips.
Another subject-matter of the present invention is composed of the use of the compositions according to the invention as defined above in the manufacture of products for the cosmetic treatment of the skin, lips, nails, hair, eyelashes, eyebrows and/or scalp, in particular of care products, sun protection products and makeup products.
The cosmetic compositions according to the invention can, for example, be used as makeup product.
The cosmetic compositions according to the invention can, for example, be used as care product and/or sun protection product for the face and/or body with a liquid to semi-liquid consistency, such as milks, relatively smooth creams, cream gels or pastes. They can optionally be packaged in an aerosol and be provided in the foam or spray form.
The compositions according to the invention in the form of vaporizable fluid lotions in accordance with the invention are applied to the skin or hair in the form of fine particles by means of pressurizing devices. The devices in accordance with the invention are well known to a person skilled in the art and comprise non-aerosol pumps or "atomizers", aerosol containers comprising a propellant and aerosol pumps using compressed air as propellant. The latter are disclosed in Patents US 4 077 441 and US 4 850 517 (forming an integral part of the content of the description).
The compositions packaged as an aerosol in accordance with the invention generally comprise conventional propellants, such as, for example, hydrofluorinated compounds, dichlorodifluoromethane, difluoroethane, dimethyl ether, isobutane, n-butane, propane or trichlorofluoromethane. They are preferably present in amounts ranging from 15 to 50% by weight, with respect to the total weight of the composition.
The following examples serve to illustrate the invention. In these examples, the amounts of the ingredients in the compositions are given as % by
weight, with respect to the total weight of the composition.
EXAMPLES 1 to 4
1. Photostability of the dibenzoylmethane
The photostabilizing effect of the 2-pyrrolidinone-4-carboxy ester compounds of formula (I) in accordance with the invention was evaluated with respect to the dibenzoylmethane derivative: Butyl Methoxy Dibenzoylmethane (avobenzone), provided for sale under the trade name "Parsol 1789" by Roche Vitamins (Examples 1, 2, 3 and 4).
The photostabilizing effect of these 2-pyrrolidinone-4-carboxy ester derivatives was also compared with that of Isopropyl Lauroyl Sarcosinate (Example A) of formula:
(Formula Removed)
Example B comprises neither pyrrolidone-4-carboxy ester compound nor isopropyl lauroyl sarcosinate.
(Table Removed)
PRINCIPLE OF THE METHOD:
The percentage of loss of dibenzoylmethane derivative brought about by the exposure to a solar simulator of a formulation spread as films with a thickness of approximately 20 urn is measured. Evaluation is carried out by HPLC analysis of the screening agent in solution, after extraction of the films, by comparing irradiated and nonirradiated samples.
EQUIPMENT AND METHOD:
Solar simulator: Oriel 1000W device equipped with a 4-inch outlet, having an 81017 filter and a dichroic mirror. The samples are exposed in a horizontal position. The UV-meter used is the Osram Centra device equipped with 2 reading heads, one for UV-A radiation and the other for UV-B radiation. The simulator/UV-meter assembly is calibrated annually by spectroradiometry. The irradiance measurements are carried out at the beginning and at the end of exposure by placing the reading heads at the position of the sample. The irradiances are: 0.35 - 0.45 mW/cra2 in UV-B radiation 16 - 18 mW/cm2 in UV-A radiation.
The residual Butyl Methoxy Dibenzoylmethane is measured by chromatography: HPLC line with diode array detector. The 2-pyrrolidinone-4-carboxy ester derivatives are introduced into the common vehicle defined above at a concentration of 10% in the presence of 1% of Butyl Methoxy Dibenzoylmethane with the composition: The loss of Butyl Methoxy Dibenzoylmethane (avobenzone) after irradiation in the same vehicle not comprising compound of formula (I) (Composition B) is also measured.
IMPLEMENTATION OF THE PHOTOSTABILITY TESTS
Approximately 20 mg of each formulation tested are spread over a surface area of 10 cm2 on a ground face of a fused silica disc. The exact amount is determined by weighing. 3 films are exposed to the
solar simulator and 3 others act as a control. The samples are exposed 3 by 3 to the light of the solar simulator for a time sufficient to deliver a UV-A dose equal to 12J corrected for the sensitivity of the UV-meter, corresponding to the decomposition of approximately 50% of the Butyl Methoxy Dibenzoylmethane (avobenzone) in the absence of photoprotective agent. At the end of the exposure, each support disc is introduced into a 600 ml container with 10 ml of an appropriate solvent (generally EtOH); the assembly is placed in an ultrasonic bath for 5 minutes. The solution is subsequently transferred into flasks suitable for the vehicle compatible with the HPLC analytical device used. The analytical conditions can be adjusted according to the active principle tested. The residual levels are calculated from the means obtained with regard to the irradiated and nonirradiated samples, as described below:
TABLE I

(Table Removed)
The 2-pyrrolidinone-4-carboxy ester compounds of formulae (j), (1), (m) and (n) of Examples 1 to 4 according to the invention have a photostabilizing effect with regard to the dibenzoylmethane derivative which is better than that obtained with Isopropyl Lauroyl Sarcosinate.

2. Formulation stability of the compositions:
The thermal stabilities of Examples 1, 2, 3 and 4 corresponding to the derivatives of the invention are compared with formulation C, which is identical to formulation A but which comprises, in place of Isopropyl Lauroyl Sarcosinate, the amidated compound ethyl N-butyl-N-acetylaminopropionate (R3535, Merck). The appearance of each formulation after storing in an oven at 45°C for 2 months is observed with the naked eye (macroscopic appearance).

(Table Removed)
It is clearly observed that, compared with ethyl N-butyl-N-acetylaminopropionate (R3535) as described in EP 717 982, compounds (j), (1), (m) and (n) of formula (I) according to the invention make it possible to obtain a good stable dispersion of the oil in the composition and, at the end, good formulation stability.

CLAIMS
1. Composition comprising, in a cosmetically acceptable vehicle, at least one UV screening system, characterized in that it comprises:
(a) at least one dibenzoylmethane derivative and
(b) at least one 2-pyrrolidinone-4-carboxy ester compound of following formula (I):
(Formula Removed)
in which:
R1 denotes a linear or branched C1-C20 alkyl radical,
R2 denotes a linear or branched C1-C20 alkyl radical
which can comprise a C5-C6 ring, the phenyl radical, the
benzyl radical or the phenethyl radical.
2. Composition according to Claim 1, where the compound of formula (I) is chosen from the following compounds (a) to (00):

(Formula Removed)
3. Composition according to Claim 2, where the compound of formula (I) is chosen from the compounds:
(Formula Removed)
4. Composition according to any one of Claims 1 to 3,
where the dibenzoylmethane derivative is 4- (tert-
butyl)-4'-methoxydibenzoylmethane or Butyl Methoxy
Dibenzoylmethane of following formula:
(Formula Removed)
5. Composition according to any one of Claims 1 to 3,
characterized in that it additionally comprises a
silicated s-triazine compound substituted by two
aminobenzoate or aminobenzamide groups of following
general formula (VI) or one of its tautomeric forms:
(Formula Removed)
in which:
- R, which are identical or different, represent a
linear or branched C1-C30 alkyl radical which is
optionally halogenated or unsaturated, a C6-C12 aryl
radical, a C1-C10 alkoxy radical, a hydroxyl radical or
the trimethylsilyloxy group;
a = 0 to 3; in addition to the units of formula
-A-(Si) (R) a (O) (3-a)/2, the organosiloxane can comprise units of formula: (R)b-(Si) (O)(4-b)/2, in which: R has the same meaning as in the formula (II) and b = 1, 2 or 3;
the group (D) denotes an s-triazine compound of following formula (VII):
(Formula Removed)
where
X represents -O- or -NR3_, with R3 representing hydrogen or a C1-C5 alkyl radical,
- R1 represents a linear or branched C1-C30 alkyl radical
which is optionally unsaturated and which can comprise
a silicon atom, a C5-C20 cycloalkyl group, optionally
substituted by 1 to 3 linear or branched C1-C4 alkyl
radicals, the - (CH2CHR4-O) mRs group or the
-CH2-CH(OH)-CH2-O-R6 group,
- R4 represents hydrogen or methyl; it being possible for the (C=O)XR1 group to be in the ortho, meta or para position with respect to the amino group,
- R5 represents hydrogen or a C1-C8 alkyl group,
- R6 represents hydrogen or a C4-C8 alkyl group,
- m is an integer ranging from 2 to 20,
- n' = 0 to 2,
- R2, which are. identical or different, represent a
hydroxyl radical, a linear or branched C1-C8 alkyl
radical or a C1-C8 alkoxy radical, it being possible for
two adjacent R2 groups on the same aromatic nucleus to
together form an alkylidenedioxy group in which the
alkylidene group comprises 1 or 2 carbon atoms,
A is a divalent radical chosen from methylene, -[CH(Si(CH3)3) ]-, ethylene or a group corresponding to one of the following formulae (VIII), (IX), (X) or (XI) :
(Formula Removed)
in which:
Z is a saturated or unsaturated and linear or branched C1-C10 alkylene diradical which is optionally substituted by a hydroxyl radical or oxygen atoms and which can optionally comprise an amino group, - W represents a hydrogen atom, a hydroxyl radical or a saturated or unsaturated and linear or branched C1-C8 alkyl radical.
6. Composition according to Claim 5, where the compound of formula (VI) is 2, 4-bis(n-butyl 4'-aminobenzoate)-6-[(3-{l,3,3,3-tetramethyl-l-[(trimethylsilyl)oxy]disiloxanyl}propyl)amino]-s-triazine of formula (5):
(Formula Removed)
7. Composition according to any one of Claims 1 to 6, characterized in that it additionally comprises other organic or inorganic screening agents active in the UV-A and/or UV-B regions which are water-soluble or fat-soluble or else insoluble in the cosmetic solvents commonly used.
8. Composition according to Claim 7, where the additional organic screening agents are chosen from anthranilates; cinnamic derivatives; salicylic derivatives; camphor derivatives; benzophenone derivatives; ß,ß-diphenylacrylate derivatives; triazine derivatives; benzotriazole derivatives; benzalmalonate derivatives; benzimidazole derivatives; imidazolines; bis-benzoazolyl derivatives; p-aminobenzoic acid (PABA) derivatives; methylenebis(hydroxyphenylbenzotriazole) derivatives; benzoxazole derivatives; screening polymers and screening silicones; dimers derived from α-alkylstyrene; 4,4-diarylbutadienes; merocyanine derivatives and their mixtures.
9. Composition according to Claim 8, characterized in that the organic UV screening agent or agents are chosen from the following compounds:
Ethylhexyl Methoxycinnamate,
Ethylhexyl Salicylate,
Homosalate,
Octocrylene,
Phenylbenzimidazole Sulfonic Acid,
Benzophenone-3,
Benzophenone-4,
Benzophenone-5,
n-Hexyl 2-(4-diethylamino-2-hydroxybenzoyl)benzoate,
4-Methylbenzylidene Camphor,
Terephthalylidene Dicamphor Sulfonic Acid,
Disodium Phenyl Dibenzimidazole Tetrasulfonate,
Methylene Bis-Benzotriazolyl Tetramethylbutylphenol,
Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine,
Ethylhexyl Triazone,
Diethylhexyl Butamido Triazone,
2,4,6-Tris(dineopentyl 4'-aminobenzalmalonate)-s-
triazine,
2,4,6-Tris(diisobutyl 4'-aminobenzalmalonate)-s-
triazine,
2,4-Bis(dineopentyl 4 ' -aminobenzalmalonate)-6-(n-butyl
4'-aminobenzoate)-s-triazine,
2,4,6-Tris (biphenyl-4-yl)-1,3,5-triazine,
2,4,6-Tris(terphenyl)-1,3,5-triazine,
Drometrizole Trisiloxane,
Polysilicone-15,
1,1-Dicarboxy(2,2'-dimethylpropyl)-4,4-
diphenylbutadiene,
2,4-Bis[5-1(dimethylpropyl)benzoxazol-2-yl-(4-
phenyl)imino]-6-(2-ethylhexyl)imino-1,3,5-triazine,
Octyl 5-N, N-diethylamino-2-phenylsulphonyl-2,4-
pentadienoate,
and their mixtures.
10. Composition according to Claim 7, characterized in that the additional inorganic screening agents are coated or uncoated metal oxide pigments.
11. Composition according to Claim 10, where the coated or uncoated metal oxide pigments have a mean primary particle size of between 5 nm and 100 nm and preferably between 10 nm and 50 nm.
12. Composition according to Claim 10 or 11, where the coated or uncoated metal oxide pigments are chosen from pigments formed of titanium oxide (amorphous or crystallized in the rutile and/or anatase form), iron oxide, zinc oxide, zirconium oxide or cerium oxide or their mixtures.
13. Composition according to any one of Claims 1 to 12, characterized in that it is provided in the form of an oil-in-water or water-in-oil emulsion.
14. Method for improving the chemical stability with
regard to UV radiation of at least one dibenzoylmethane
derivative as defined in any one of the preceding
claims, characterized in that the said dibenzoylmethane
derivative is combined with an effective amount of at
least one 2-pyrrolidinone-4-carboxy ester compound of
formula (I) as defined in the preceding claims.
15. Use of at least one 2-pyrrolidinone-4-carboxy
ester compound of formula (I) as defined in the
preceding claims in a composition comprising, in a
cosmetically acceptable vehicle, at least one
dibenzoylmethane derivative as defined in any one of
the preceding claims with the aim of improving the
effectiveness of the said composition with regard to
UV-A rays.