IMPROVING THE PHOTOSTABILITY OF THE THIOPYRIDINONE COMPOUND WITHOUT THE USE OF UV FILTERS

Abstract

ENHANCING THE PHOTOSTABILITY OF THE THIOPYRIDINONE COMPOUND WITHOUT THE USE OF UV FILTERS This disclosure relates to cosmetic compositions and methods of using cosmetic compositions for the benefit of the skin. The cosmetic compositions typically include: (a) thiopyridinone-type compounds; and (b) one or more UV enhancers. The compositions offer multiple benefits to the skin. For example, the compositions are particularly useful for whitening the skin and improving its appearance. Figure for the abstract: none

Description

Title of the invention: IMPROVING THE PHOTOSTABILITY OF THE THIOPYRIDINONE COMPOUND WITHOUT THE USE OF UV FILTERS SCOPE OF DISCLOSURE

[0001] Cosmetic compositions offering improved photostability of Thiopyridinone type compounds without the use of UV filters and related usage methods. CONTEXT OF THE DISCLOSURE

[0002] The ultimate goal of the cosmetics industry has always been to deliver products with skin benefits such as hydration, anti-aging effects, whitening, cleansing, and others. Skin whitening and lightening always attract consumer interest, especially among those with dark or dull complexions. Unfortunately, at different times in their lives, some people develop darker and / or more pigmented spots on their skin, particularly on their hands, giving the skin an uneven appearance. These spots are primarily due to a high concentration of melanin in the keratinocytes located on the skin's surface.

[0003] Consequently, there is a need in the technology for a cosmetic composition which offers a stable formulation which includes active substances to improve the softness and radiance of the skin, lighten the skin, dark spots or a combination of these elements.

[0004] The ultimate goal of the cosmetics industry has always been to deliver products with skin benefits such as hydration, anti-aging effects, whitening, cleansing, and others. Skin whitening and lightening continue to be of interest to consumers, especially those with dark or dull complexions. Unfortunately, at various times in their lives, some people develop darker and / or more pigmented spots on their skin, particularly on their hands, giving the skin an uneven appearance. These spots are primarily due to a high concentration of melanin in the keratinocytes located on the skin's surface.

[0005] It is known that certain thiopyridinone compounds exhibit good depigmenting activity, even at low concentrations, see for example documents WO2012080075 and WO2017 / 102349. The thiopyridinone compound can exhibit strong depigmenting or bleaching effects by reducing melanin production. DISCLOSURE SUMMARY

[0006] This disclosure relates to cosmetic compositions and methods of using the compositions for the benefit of the skin. The compositions improve the appearance of the skin. The compositions are unique in their ability to photostabilize thiopyridinone-type compounds. The inventors have discovered that the combination of ethylhexyl methoxycrylene and diethyl syringylidene malonate unexpectedly enhances the photostability of thiopyridinone (I) or (T)-type compounds. This disclosure minimizes the degradation of thiopyridinone-type compounds when exposed to light and provides the ability to photostabilize thiopyridinone-type compounds without the use of UV filters.

[0007] The compositions of this disclosure typically include:

[0008] i) at least one compound selected from the compounds of formula (I) and the tautomer of formula (!') below; and their salts, optical isomers, racemates, and / or solvates such as hydrates, alone or in mixtures:

[0009] Formulas (I) and (I') in which:

[0010] -RI designates a radical chosen from:

[0011] a) a hydrogen atom;

[0012] b) a linear saturated C1-C10 or C3-C10 branched alkyl group optionally substituted by one or more groups, which may be identical or different, selected from:

[0013] i) -O-R3

[0014] ii) -S-R3;

[0015] - R2 denotes a radical chosen from:

[0016] a) a hydrogen atom;

[0017] b) a linear saturated hydrocarbon group in C1-C12 or branched in C3-C12 or cyclic in C3-C8, optionally substituted by one or more groups, which may be identical or different, selected from:

[0018] i) -O-R3

[0019] ii) -S-R3

[0020] iii) -C(O)-O-R3 ;

[0021] iv) an aryl group in C5-C12, optionally substituted by one or more hydroxyl groups and / or by one or more alkoxy radicals in C1-C8;

[0022] c) an aryl group at C5-C12, optionally substituted by one or more hydroxyl groups and / or by one or more alkoxy radicals at C1-C8

[0023] -R3 designates a radical chosen from:

[0024] a) a hydrogen atom;

[0025] b) a linear saturated alkyl group in C1-C10 or branched in C3-C10;

[0026] ii) one or more UV enhancers; and

[0027] in which the association of one or more UV enhancers improves the photostability of thiopyridinone-type compounds.

[0028] In some cases, one or more UV enhancers are selected from ethylhexyl methoxycrylene, diethyl syringylidene malonate, and a mixture thereof. In some cases, one or more UV enhancers are present at concentrations ranging from approximately 0.01% to approximately 10% by weight, relative to the total weight of the cosmetic composition.

[0029] In some cases, the thiopyridone-type compound is present from approximately 0.01 to approximately 10% by weight, relative to the total weight of the cosmetic composition. In some cases, the thiopyridone compound is present from approximately 0.1 to approximately 5% by weight, relative to the total weight of the cosmetic composition. In one embodiment, the thiopyridinone compound is present from approximately 0.5 to approximately 3% by weight, relative to the total weight of the cosmetic composition.

[0030] In some embodiments, ethylhexyl methoxycrylene is present from approximately 0.2 to approximately 3% by weight, relative to the total weight of the cosmetic composition. In other embodiments, ethylhexyl methoxycrylene is present from approximately 0.3 to approximately 2.8% by weight, relative to the total weight of the cosmetic composition.

[0031] In some embodiments, diethyl syringylidene malonate is present from about 0.2 to about 3% by weight, relative to the total weight of the cosmetic composition.

[0032] In one or more embodiments, the cosmetic composition may have a pH ranging from about 4.5 to about 6.5, preferably from about 5 to about 6.

[0033] As mentioned above, the compositions are unique in their ability to photostabilize thiopyridinone-type compounds without the use of UV filters. Consequently, in certain aspects, this disclosure relates to processes for photostabilizing thiopyridinone-type compounds with one or more UV enhancers, including the combination of thiopyridinone-type compounds with one or more UV enhancers, thereby improving the photostability of thiopyridinone-type compounds.

[0034] Finally, this disclosure relates to methods of using the compositions described in this document, for example in skin treatment. This disclosure relates to skin treatment processes that include the application of the cosmetic composition of this disclosure to the skin. The compositions may be used in processes to: depigment, lighten, and bleach keratinous materials, as well as improve the appearance of the skin.

[0035] These and other aspects of the invention are described in more detail in the detailed description of the invention.

[0036] This disclosure describes examples of embodiments according to general inventive concepts and is not intended to limit the scope of the invention in any way. Indeed, the invention as described in the document is broader than, and not limited by, the examples of embodiments presented herein, and the terms used herein have their full ordinary meaning. DISCLOSURE DETAILS

[0037] This communication relates to cosmetic compositions typically comprising at least one compound corresponding to the following formula (I) or I'), referred to as "thiopyridinone type compound".

[0038] This disclosure relates to cosmetic compositions and methods of using the compositions for the benefit of the skin. The compositions improve the appearance of the skin. The compositions are unique in their ability to photostabilize thiopyridinone compounds. The inventors have discovered that the combination of ethylhexyl methoxycrylene and diethyl syringylidene malonate unexpectedly enhances the photostability of thiopyridinone compounds. This disclosure improves the stability of thiopyridinone compounds when exposed to light and provides the ability to photostabilize the thiopyridinone compound without the use of UV filters.

[0039] The compositions of this disclosure typically include:

[0040] i) at least one compound selected from the compounds of formula (I) and the tautomer of formula (!') below; and their salts, optical isomers, racemates, and / or solvates such as hydrates, alone or in mixtures:

[0041] [Chem.l] H (U (FJ

[0042] Formulas (I) and (I') in which:

[0043] -RI designates a radical chosen from:

[0044] a) a hydrogen atom;

[0045] b) a linear saturated C1-C10 or C3-C10 branched alkyl group optionally substituted by one or more groups, which may be identical or different, selected from:

[0046] i) -O-R3

[0047] ii) -S-R3;

[0048] - R2 denotes a radical chosen from:

[0049] a) a hydrogen atom;

[0050] b) a linear saturated hydrocarbon group in C1-C12 or branched in C3-C12 or cyclic in C3-C8, optionally substituted by one or more groups, which may be identical or different, selected from:

[0051] i)-O-R3

[0052] ii) -S-R3

[0053] iii) -C(O)-O-R3 ;

[0054] iv) an aryl group in C5-C12, optionally substituted by one or more hydroxyl groups and / or by one or more alkoxy radicals in C1-C8;

[0055] c) an aryl group at C5-C12, optionally substituted by one or more hydroxyl groups and / or by one or more alkoxy radicals at C1-C8

[0056] -R3 designates a radical chosen from:

[0057] a) a hydrogen atom;

[0058] b) a linear saturated alkyl group in C1-C10 or branched in C3-C10;

[0059] ii) one or more UV enhancers; and

[0060] in which the association of one or more UV enhancers improves the photostability of thiopyridinone compounds.

[0061] Thiopyridinone-type compounds

[0062] For the purposes of this disclosure, and unless otherwise indicated:

[0063] -a "linear saturated hydrocarbon group in Ci-Ci2 or branched in C3-Ci2" is equivalent to a "linear (C1-C12) or branched (C3-C12) alkyl group" which corresponds to a linear C1-C12 or branched C3-C12 saturated hydrocarbon-based group, and preferably a linear C1-C10 or branched C3-C10 hydrocarbon-based group, more preferably a linear C1-C6 or branched C3-C6 hydrocarbon-based group; preferably, the linear or branched groups may be selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl and tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl.

[0064] More preferably, the linear or branched saturated alkyl groups can be selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl and tert- butyl, pentyl, hexyl, heptyl and octyl, such as methyl, ethyl, n-pentyl, n-nonyl, isobutyl.

[0065] -a saturated C3-C8 hydrocarbon cyclic group is a mono- or bicyclic cycloalkyl group containing 3 to 8 carbon atoms, in particular a monocyclic cycloalkyl group in C5 to C7 such as the cyclohexyl group,

[0066] -an "alkoxy radical" is an alkyl-oxy radical for which the alkyl radical is a linear hydrocarbon-based radical or branched in Ci-Ci6 and preferably in Cr C8;

[0067] -when the alkoxy group is optionally substituted, this implies that the alkyl group is optionally substituted as defined above;

[0068] -an "aryl" group represents a carbon-based group, monocyclic or bicyclic, fused or not, comprising from 5 to 12 carbon atoms, preferably from 6 to 10 carbon atoms, and in which at least one ring is aromatic; preferably, the aryl radical is a phenyl, biphenyl, naphthyl group, more preferably a phenyl group;

[0069] - the term "at least one" is equivalent to the term "one or more"; and

[0070] - the term "inclusive" for a range of concentrations means that the limits of this ranges are included in the defined range.

[0071] The salts of compounds of formula (I), (I'), (II) or (II1) as defined below include conventional non-toxic salts of said compounds, such as those formed from an organic or inorganic acid or an organic or inorganic base.

[0072] Examples of salts of compounds of formula (I), (I'), (II) or (II') include:

[0073] the salts obtained by adding the compound of formula (I) or (II) to: - a mineral base, such as sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonium hydroxide, magnesium hydroxide, lithium hydroxide, and sodium, potassium or calcium carbonate or hydrogen carbonate, for example;

[0074] or - an organic base such as a primary, secondary or tertiary alkylamine, for example triethylamine or butylamine. This primary, secondary or tertiary alkylamine may include one or more nitrogen and / or oxygen atoms and may therefore include, for example, one or more alcohol functions; examples include 2-amino-2-methylpropanol, ethanolamine, triethanolamine, 2-dimethylaminopropanol, 2-amino-2-(hydroxymethyl)-1,3-propanediol, 3-(dimethylamino)propylamine.

[0075] Salts of amino acids, for example lysine, arginine, guanidine, glutamic acid, and aspartic acid, can also be cited. Advantageously, salts of compounds of formula (I) or (II) (when they include a carboxy group) can be chosen from alkali or alkaline-earth metal salts such as sodium, potassium, calcium or magnesium salts and ammonium salts.

[0076] A "salt of an organic or inorganic acid" is more particularly chosen from among the salts chosen from a salt derived from i) hydrochloric acid HCl, ii) hydrobromic acid HBr, iii) sulfuric acid H2SO4, iv) alkylsulfonic acids: Alk-S(O)2OH such as methanesulfonic acid and ethanesulfonic acid; v) arylsulfonic acids: Ar-S(O)2OH such as benzenesulfonic acid and toluenesulfonic acid; vi) citric acid; vii) succinic acid; viii) tartaric acid; ix) lactic acid; x) alkoxysulfinic acids: Alk-OS(O)OH such as methoxysulfinic acid and ethoxysulfinic acid; xi) aryloxysulfinic acids such as tolueneoxysulfinic acid and phenoxysulfinic acid; xii) phosphoric acid H3PO4; xiii) acetic acid CH3C(O)OH; xiv) triflic acid CF3SO3H; and xv) tetrafluoroboric acid HBF4;

[0077] Acceptable solvates of the compounds described in this disclosure include conventional solvates such as those formed during the preparation of said compounds due to the presence of solvents. Examples include solvates due to the presence of water or linear or branched alcohols, such as ethanol or isopropanol.

[0078] Optical isomers are in particular enantiomers and diastereomers.

[0079] Therefore, the compounds used according to this disclosure correspond to formula (I) or tautomer (F) or their salts, their optical isomers, racemates, and / or solvates such as hydrates and their derivatives, alone or in mixture.

[0080] [Chem.2] (0 01

[0081] Formulas (I) and (F) in which:

[0082] RI designates a radical chosen from:

[0083] a) a hydrogen atom;

[0084] b) a linear saturated C1-C10 or C3-C10 branched alkyl group optionally substituted by one or more groups, which may be identical or different, selected from:

[0085] i) -O-R3

[0086] ii) -S-R3;

[0087] R2 denotes a radical chosen from:

[0088] a) a hydrogen atom;

[0089] b) a linear saturated hydrocarbon group in C1-C12 or branched in C3-C12 or cyclic in C3-C8, optionally substituted by one or more groups, which may be identical or different, selected from:

[0090] i) -O-R3

[0091] ii) -S-R3

[0092] iii) -C(O)-O-R3 ;

[0093] iv) an aryl group in C5-C12, optionally substituted by one or more hydroxyl groups and / or by one or more alkoxy radicals in C1-C8;

[0094] c) an aryl group at C5-C12, optionally substituted by one or more hydroxyl groups and / or by one or more alkoxy radicals at C1-C8

[0095] R3 designates a radical chosen from:

[0096] a) a hydrogen atom;

[0097] b) a linear saturated alkyl group in C1-C10 or branched in C3-C10;

[0098] Compound (I1) is the tautomeric form of compound (I) when a tautomeric equilibrium exists according to the following scheme:

[0099] [Chem.3]

[0100] According to one embodiment of the disclosure, Ri represents a hydrogen atom.

[0101] According to another embodiment of the invention, Ri represents a linear (Ci-CiO) or branched (C3-C10) alkyl group, in particular a linear (Cr-C6) or branched (C3-C6) alkyl group, such as methyl, ethyl, n-pentyl, n-nonyl, isobutyl, more preferably ethyl. In particular, said alkyl group of Ri is unsubstituted.

[0102] According to one embodiment of the disclosure, R2 represents a hydrogen atom.

[0103] According to another embodiment of the disclosure, R2 represents an alkyl group linear (C1-C10) or branched (C3-C10), including a linear or branched (C3-C6) alkyl group (Ci-C6), such as methyl, ethyl, n-pentyl, n-nonyl, isobutyl, more preferentially methyl or ethyl; said alkyl group of R2 not being substituted.

[0104] According to another embodiment of the invention, R2 represents a linear (Ci-Ci0) or branched (C3-Ci0) alkyl group, in particular a linear (Ci-C6) or branched (C3-C6) alkyl group, such as methyl, ethyl, n-pentyl, n-nonyl, isobutyl, more preferably methyl or ethyl; said alkyl group being substituted by one or more groups selected from i), ii), iii) and iv) as defined herein before, preferably, said alkyl group being substituted by one or more groups selected from i), ii) and iii), more preferably by one or more groups selected from i) and iii), better substituted by a group iii) as carboxy.

[0105] Another variant for the radical R2 is that said alkyl group is substituted by a group iv) in particular substituted by a phenyl group.

[0106] According to another embodiment of the invention, R2 represents a cycloalkyl group (in C3-C8), preferably a cycloalkyl group (in C5-C7) such as cyclohexyl.

[0107] According to another embodiment of the invention, R2 represents an aryl group in C5-Ci2 optionally substituted by one or more hydroxyls and / or by one or more alkoxy radicals in CrC8, preferably a phenyl group in particular unsubstituted.

[0108] According to one embodiment, R3 represents a hydrogen atom.

[0109] According to another embodiment, R3 represents a linear saturated alkyl group in Ci-Cio or branched in C3-Ci0; in particular a linear alkyl group (in Ci-C6) or a branched alkyl group (in C3-C6), preferably an alkyl group (in C1-C4) such as the methyl group.

[0110] preferably, compounds of formula (I) and the tautomer (!') or their salts, their optical isomers, racemates, and / or solvates such as hydrates and their derivatives, alone or in mixture;

[0111] have the following meanings:

[0112] RI designates a radical chosen from:

[0113] a) a hydrogen atom;

[0114] b) a linear saturated alkyl group in C1-C6 or branched in C3-C6 optionally substituted by one or more groups, which may be identical or different, selected from:

[0115] i)-O-R3

[0116] ii)-S-R3;

[0117] preferably optionally substituted by one or more groups i)

[0118] R2 denotes a radical chosen from:

[0119] a) a hydrogen atom;

[0120] b) a linear saturated hydrocarbon group in C1-C10 or branched in C3-C10 or cyclic in C3-C8 such as in C5-C6, optionally substituted by one or more groups, which may be identical or different, selected from:

[0121] i) -O-R3

[0122] ii) -SR-3

[0123] iii) -C(O)-O-R3 ;

[0124] iv) a phenyl group optionally substituted by one or more hydroxyl groups and / or by one or more C1-C4 alkoxy radicals such as methoxy;

[0125] preferably substituted by one or more groups selected from i) and iii), preferably iii) such that carboxy

[0126] R3 designates a radical chosen from:

[0127] a) a hydrogen atom;

[0128] b) a linear saturated alkyl group in C1-C6 or branched in C3-C6;

[0129] Preferably, the compounds of formula (I) and the tautomer (!') or their salts, their optical isomers, racemates, and / or solvates such as hydrates and their derivatives, alone or in mixture;

[0130] have the following meanings:

[0131] RI designates a radical chosen from:

[0132] a) a hydrogen atom;

[0133] b) a linear saturated alkyl group in C1-C4 or branched in C3-C4 optionally substituted by one or more groups, which may be identical or different, selected from i) -OR3, more preferably unsubstituted;

[0134] R2 denotes a radical chosen from:

[0135] a) a hydrogen atom;

[0136] b) a linear saturated hydrocarbon group in C1-C10 or branched in C3-C10 or cyclic in C3-C8 as in C5-C6, optionally substituted by one or more groups, which may be identical or different, selected from:

[0137] i) -O-R3

[0138] iii) -C(O)-O-R3 ;

[0139] iv) an aryl group in C5-C12, optionally substituted by one or more hydroxyls and / or by one or more alkoxy radicals in C1-C4;

[0140] R3 designates a radical chosen from:

[0141] a) a hydrogen atom;

[0142] b) a linear saturated alkyl group in C1-C4 or branched in C3-C4 such as methyl or ethyl.

[0143] Preferably, the compounds of formula (I) and the tautomer (I1) or their salts, their optical isomers, racemates, and / or solvates such as hydrates and their derivatives, alone or in mixture;

[0144] have the following meanings:

[0145] RI is a hydrogen atom; and

[0146] R2 denotes a radical chosen from:

[0147] a) a hydrogen atom;

[0148] b) a linear saturated hydrocarbon group in C1-C5 or branched in C3-C5 or cyclic in C3-C8 such as in C5-C6, optionally substituted by one or more groups, which may be identical or different, selected from v) -C(O)-O-R3, preferably substituted by a group iii) -C(O)-O-R3;

[0149] R2 is even more preferably a linear saturated Cl-C4 hydrocarbon group or a C3-C4 branched group substituted by a iii) -C(O)-OR3 group.

[0150] According to another preferred embodiment, the compounds of formula (I) and the tautomer (I') are chosen from the compounds of formula (II) as well as their tautomers, their salts, their solvates and their optical isomers, and their racemates, alone or in mixture:

[0151] [Chem.4] rVr-'V''*» 'Tr'- SH ... £ xo O' y ^3 y Y & o W SH ' (m on

[0152] Formulas (II) and (II') in which RI and R3 have the same meaning as for the compounds of formula (I) and (I') and X denotes an alkylene radical -(CH2)n- n being an integer from inclusively 1 to 10, preferably from 1 to 6, more preferably from 1 to 4, such that 1, preferably R3 represents a hydrogen atom.

[0153] Among the compounds of formula (I), the following compounds are preferably used, and their tautomer or their salts, their optical isomers, racemates, and / or solvates such as hydrates and their derivatives, alone or in mixture:

[0154] [Tables 1] No. Structure Chemical Name CAS No. 1 Cl H ''''l'A H N-ethyl-2-thioxo-1,2-dihydropyridine-3-car boxamide 91859-75-5 2 N-methyl-2-thioxo-1,2-dihydropyridine-3-car boxamide 91859-74-4 3 ■'v. xv''' N-octyl-2-thioxo-1,2-dihy dropyridine- 3 -c ar boxamide 91859-77-7 4 xFlx --------< ■■ x ) / \ / A k........' ü N-phenyl-2-thioxo-1,2 -dihydropyridine-3-car boxamide 104857-16-1 6 HH N-cyclohexyl-2-thioxo -1,2-dihydropyridine-3-carboxamide 91859-78-8 7 aX- N-[2-(4-methoxyph enyl)ethyl]-2-thioxo-1,2-dihydropyridine-3-carboxamide 923682-88-6 8 .,-- S CH? N-(2-méthylpropyl)-2-thioxo-1,2-dihydropy ridine-3-carboxamide 1100027-79- 9 9 N-pentyl-2-thioxo-1,2 -dihydropyridine-3-car boxamide 330667-57-7 10 N-nonyl-2-thioxo-1,2-dihy dropyridine- 3 -c ar boxamide 1031149-44- 6 11 H A. N\ AA Ct-I N-(2-hydroxyéthyl)-2-thioxo-1,2-dihydropy ridine-3-carboxamide 12 H q "'A'""" ""AA [ N,N-diéthyl 2-mercap tonicotinamide 13 H A-i—-\ / V S ^CMs N-éthyl-N-(2-hydrox yéthyl)-2-thioxo-1,2-dihy dropyridine- 3 -c ar boxamide 14 N-(2,3-dihydroxypropyl)-2-thioxo-1,2-dihydropyridine-3-carboxamide 15 .OH 0 < ...xx .,-''~J^ X'>K N-( 1,3-dihydroxypropyl-2-yl)-2-thioxo-1,2-dihydropyridine-3-carboxamide 16 f ^Mi fY YT° "O x h3c N- [(2-thioxo-1,2-dihydropyridine-3-yl)carboxamide]ethyl alaninate 17 çCŸ J ' N- [(2-thioxo-1,2-dihydropyridine-3-yl)carboxamide]ethyl phenyl alaninate 18 'ky'' xJyv CH> 0., 8t § N-methyl-N-[(2-thioxo 1,2-dihydropyridin-3-yl)carbonyl]ethyl glycinate 19 [j N- [(2-thioxo-1,2-dihydropyridin-3-yl)carbonyl]ethyl glycinate 20 HG N- [(2-thioxo-1,2-dih ydropyridin-3-yl)car bonyl] glycine 21 0' hyl)-2-thioxo-1,2-dih ydropyridine-3-carbox amide 23 Yï w S $ N-(3-methoxypropyl)-2-thioxo-1,2-dihydr opyridine-3-carboxami de 24 TT N-butyl-2-thioxo-1,2-dihy dropyridine- 3 -c ar boxamide

[0155] Among these compounds, the following compounds are particularly preferred:

[0156] [Tables2] No. Structure Chemical Name CAS No. 1 X'v" NH N-ethyl-2-thioxo-1,2-dihydropyridine-3-carboxamide 91859-75-5 2 <■ N-methyl-2-thioxo-1,2-dihydropyridine-3-carboxamide 91859-74-4 4 7"\ ,x"-. N-benzyl-2-thioxo-1,2-dihydropyridine-3-carboxamide 91859-79-9 6 A AA ^îA HHAH N-cyclohexyl-2-thioxo-1,2-dihydropyridine-3-carboxamide 91859-78-8 7 A £X“ (X * <4 N-[2-(4-methoxyphenyl)ethyl]-2-thioxo-1,2-dihydropyridine-3-carboxamide 923682-88-6 9 pA^^ xv' "'A N-pentyl-2-thioxo-1,2 -dihydropyridine-3-carboxamide 330667-57-7 11 SH N-(2-hydroxyethyl)-2-thioxo-1,2-dihydr opyridine-3-carbox amide 12 y) \ / / 3-v Y -, N-(2,3-dihydroxypropyl)-2-thioxo-1,2-dihydropyridine-3-carboxamide 15 Zs AX -ou i 'X : ' Yr s N-( 1,3-dihydroxypropyl-2-yl)-2-thioxo-1,2-dihydropyridine-3-carboxamide 16 L (ZX?^” / N,C N- [(2-thioxo-1,2-dihydropyridine-3-yl)carboxyl]ethyl alaninate 17 YYYH N- [(2-thioxo-1,2-dihydropyridine-3-yl)carboxyl]ethyl phenyl alaninate 18 CH> $x N-methyl-N-[(2-thi oxo-1,2-dihydropyrid in-3-yl)carbonyl]gly ethyl cinate 19 or >r H q S N- [(2-thioxo-1,2-dih ydropyridin-3-yl)car bonyl] glycine 21 H CH> OH N-methyl-N-[(2-thi oxo-1,2-dihydropyrid in-3-yl)carbonyl]gly cine More preferably, among these compounds, the following compounds are more

[0157]

[0158] particularly preferred: [Tables 3] No. Structure Chemical Name CAS No. 1 er \ '\___7 / WX > / / S N-ethyl-2-thioxo-1,2-dihydropyridine-3-carboxamide 91859-75-5 9 c 0 N-pentyl-2-thioxo-1,2-dihydropyridine-3-carboxamide 330667-57-7 16 o CH, J.....L ... 1X7 \ / h3c N- [(2-thioxo-1,2-dihydropyridine-3-yl)carboxamide]ethyl alaninate 18 X>X n' x CH' N-methyl-N-[(2-thioxo-1,2-dihydropyridine-3-yl)carbonyl]ethyl cyanate 19 l G x'S / $* ' "1 YK' X, Àx 0 N- [(2-thioxo-1,2-dih ydropyridin-3-yl)car bonyl]ethyl glycinate 20 [ „ 5 « । Even more preferentially, among these compounds, the following compounds are more

[0159]

[0160]

[0161]

[0162] particularly preferred: [Tables4] No. Structure Chemical Name CAS No. 18 1 _ f 1 TTH | CH, N-methyl-N-[(2-thi oxo-1,2-dihydropyridin-3-yl)carbonyl]glycine ethyl 19 O !! H N- [(2-thioxo-1,2-dihydropyridin-3-yl)carbonyl]ethyl glycinate 20 Â rc » f H N- [(2-thioxo-1,2-dihydropyridin-3-yl)carbonyl]glycine 21 Q . / X 0 L Jx CH., OH N-methyl-N-[(2-thi oxo-1,2-dihydropyridin-3-yl)carbonyl]glycine In a most preferred embodiment, the compound according to this disclosure is as follows: [Tables5]

[0163] All the compounds can be obtained by a chemical process known to those skilled in the art, using commercially available reagents. For example, the synthesis process disclosed in European patent application EP3 390 363 can be used.

[0164] The composition used according to the disclosure comprises at least one compound of formulas (I) and / or (II) as described above, in a physiologically acceptable medium.

[0165] Compounds (I), (I'), (II) and / or (II1) may be present in the composition according to the disclosure, in an amount ranging for example from 0.01% to 10% by weight, preferably from 0.1% to 5% by weight, in particular from 0.5% to 3% by weight, relative to the total weight of the composition. UV enhancers

[0166] Ethylhexyl methoxycrylene and diethyl syringylidene malonate have been used to enhance the SPF of organic UV filtering agents. These compounds, alone or in combination, enhance the SPF of the organic UV filtering agent because they act as highly effective singlet-state extinguishers. In the present disclosure, the UV enhancers are used in the photostabilization of thiopyridone.

[0167] Ethylhexylméthoxycrylène

[0168] In some cases, ethylhexyl methoxycrylene is present at approximately 0.2 to 3% by weight, relative to the total weight of the cosmetic composition. In various embodiments, ethylhexyl methoxycrylene is present at approximately 0.3 to approximately 2.8% by weight, relative to the total weight of the cosmetic composition. The total amount of ethylhexyl methoxycrylene in the compositions may be, for example, approximately 0.2 to approximately 3% by weight, relative to the total weight of the cosmetic composition. In some cases, the total amount of ethylhexyl methoxycrylene in the compositions can be from about 0.2% by weight to about 2.9% by weight, about 2.8% by weight, about 2.7% by weight, about 2.6% by weight, about 2.5% by weight, about 2.4% by weight, about 2.3% by weight, about 2.2% by weight, about 2.1% by weight, about 2.0% by weight or about 1.8% by weight.Similarly, in some cases, the total amount of ethylhexyl methoxycrylene in the compositions may be, for example, from about 0.2 to about 2.8% by weight, about 2.7% by weight, about 2.6% by weight, about 2.5% by weight, about 2.4% by weight, about 2.3. % by weight, approximately 2.2% by weight, approximately 2.1% by weight, approximately 2.0% by weight or approximately 1.8% by weight. In addition, the total amount of ethylhexyl methoxycrylene in the compositions may be from approximately 0.25 to approximately 3% by weight, approximately 2.9% by weight, approximately 2.8% by weight, approximately 2.7% by weight, approximately 2.6% by weight, approximately 2.5% by weight, approximately 2.4% by weight, approximately 2.3% by weight, approximately 2.2% by weight, approximately 2.1% by weight, approximately 2.0% by weight or approximately 1.8% by weight. Furthermore, the total amount of ethylhexyl methoxycrylene in the compositions can be from about 0.3 to about 3% by weight, about 2.9% by weight, about 2.8% by weight, about 2.7% by weight, about 2.6% by weight, about 2.5% by weight, about 2.4% by weight, about 2.3% by weight, about 2.2% by weight, about 2.1% by weight, about 2.0% by weight or about 1.8% by weight.Finally, the total amount of ethylhexyl methoxycrylene in the compositions can be from about 0.3 to about 2.9% by weight, from about 0.3 to about 2.8% by weight, from about 0.3 to about 2.7% by weight, from about 0.3 to about 2.6% by weight, from about 0.3 to about 2.5% by weight, or about 2.4% by weight.

[0169] Diethylhexyl syringylidene malonate

[0170] In some embodiments, diethyl syringylidene malonate is present from about 0.2 to about 3% by weight, relative to the total weight of the cosmetic composition.

[0171] In some cases, diethyl syringylidene malonate is present at approximately 0.2 to 3% by weight, relative to the total weight of the cosmetic composition. In various embodiments, diethyl syringylidene malonate is present at approximately 0.3 to approximately 2.8% by weight, relative to the total weight of the cosmetic composition. The total amount of diethyl syringylidene malonate in the compositions may be, for example, approximately 0.2 to approximately 3% by weight, relative to the total weight of the cosmetic composition. In some cases, the total amount of diethyl syringylidene malonate in the compositions can be from about 0.2% by weight to about 2.9% by weight, about 2.8% by weight, about 2.7% by weight, about 2.6% by weight, about 2.5% by weight, about 2.4% by weight, about 2.3% by weight, about 2.2% by weight, about 2.1% by weight, about 2.0% by weight or about 1.8% by weight.Similarly, in some cases, the total amount of diethyl syringylidene malonate in the compositions may be, for example, from approximately 0.2 to approximately 2.8% by weight, approximately 2.7% by weight, approximately 2.6% by weight, approximately 2.5% by weight, approximately 2.4% by weight, approximately 2.3% by weight, approximately 2.2% by weight, approximately 2.1% by weight, approximately 2.0% by weight, or approximately 1.8% by weight. Furthermore, the total amount of diethyl syringylidene malonate in the compositions may be from approximately 0.25 to approximately 3% by weight, approximately 2.9% by weight, approximately 2.8% by weight, approximately 2.7% by weight, approximately 2.6% by weight, approximately 2.5% by weight, or approximately 2.4% by weight. approximately 2.3% by weight, approximately 2.2% by weight, approximately 2.1% by weight, approximately 2.0% by weight, or approximately 1.8% by weight. Furthermore, the total amount of diethyl syringylidene malonate in the compositions may be from approximately 0.3% to approximately 3% by weight, approximately 2.9% by weight, approximately 2.8% by weight, approximately 2.7% by weight, approximately 2.6% by weight, approximately 2.5% by weight, approximately 2.4% by weight, approximately 2.3% by weight, approximately 2.2% by weight, approximately 2.1% by weight, approximately 2.0% by weight, or approximately 1.8% by weight. Finally, the total amount of diethyl syringylidene malonate in the compositions can be from about 0.3 to about 2.9% by weight, about 0.3 to about 2.8% by weight, about 0.3 to about 2.7% by weight, about 0.3 to about 2.6% by weight, about 0.3 to about 2.5% by weight, or about 2.4% by weight.

[0172] The total quantity of UV enhancers in the compositions may be, for example, from about 0.2 to about 0.5%, relative to the total weight of the cosmetic composition. In some cases, the total quantity of UV enhancers in the compositions may be, for example, from about 0.2, 0.22, 0.24, 0.26, 0.28, 0.30, 0.32, 0.34 to about 0.34, 0.36, 0.38, 0.40, 0.42, 0.44, 0.46, 0.48 or 0.5% by weight, relative to the total weight of the cosmetic composition. pH correcting agent

[0173] The composition according to the present invention may comprise at least one pH-adjusting agent (pH corrector). Two or more pH-adjusting agents may be used in combination. Thus, a single type of pH-adjusting agent or a combination of different types of pH-adjusting agents may be used.

[0174] As a pH correcting agent, at least one acidifying agent and / or at least one basifying agent (alkaline agent) may be used.

[0175] The acidifying agent may be a monovalent or polyvalent acid, such as divalent.

[0176] Acidifying agents may be, for example, mineral (inorganic) acids such as hydrochloric acid, sulfuric acid, phosphoric acid, or organic acids such as carboxylic acids, for example tartaric acid, citric acid and lactic acid, as well as sulfonic acids.

[0177] The basifying agent may be a monovalent or polyvalent base, such as divalent.

[0178] Alkalizing agents can be mineral (inorganic) or organic, or hybrid.

[0179] Mineral alkalizing agents may be selected from liquid ammonia; alkali metal carbonates or bicarbonates such as sodium or potassium carbonates and sodium or potassium bicarbonates; alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; and mixtures thereof.

[0180] Organic alkalizing agents may be chosen from among organic amines whose pKb at 25 °C is less than 12, preferably less than 10, and even more advantageously less than 6. It should be noted that this is the pKb corresponding to the highest basicity function. Furthermore, organic amines do not include any fatty alkyl or alkenyl chains comprising more than ten carbon atoms.

[0181] The organic alkalizing agent may be chosen, for example, from the alkanolamines, oxyethylenated and / or oxypropylenated ethylenediamines, amino acids and amine compounds of formula (III) below: R. R.

[0182] in which

[0183] W represents a divalent Ci-C6 alkylene radical optionally substituted by one or more hydroxyl groups or a Ci-C6 alkyl radical, and optionally interrupted by one or more heteroatoms such as O and N, and

[0184] Rx, Ry, Rz and Rt, which may be identical or different, represent a hydrogen atom or an alkyl radical in Ci-C6, hydroxyalkyl in Ci-C6, or aminoalkyl in CrC6.

[0185] Examples of amine compounds of formula (III) that may be cited include 1,3-diaminopropane, 1,3-diamino-2-propanol, spermine and spermidine.

[0186] The term "alkanolamine" designates an organic amine comprising a primary, secondary or tertiary amine function, and one or more linear or CrC8 branched alkyl groups bearing one or more hydroxyl radicals.

[0187] Alkanolamines such as monoalkanolamines, dialcanolamines, or trialcanolamines comprising one to three identical or different C1-C4 hydroxyalkyl radicals may be suitable for the present disclosure. Examples of such compounds include monoethanolamine (MEA), diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, N-dimethylaminoethanolamine, 2-amino-2-methyl-1-propanol, triisopropanolamine, 2-amino-2-methyl-1,3-propanediol, 3-amino-1,2-propanediol, 3-dimethylamino-1,2-propanediol, and tris(hydroxymethylamino)methane.

[0188] The amino acids that may be used are of natural or synthetic origin, in their L, D or racemic form, and comprise at least one acid function chosen more particularly from among the carboxylic acid, sulfonic acid, phosphonic acid or phosphoric acid functions. The amino acids may be in neutral or ionic form.

[0189]

[0190]

[0191]

[0192]

[0193] Examples of amino acids that may be used in this disclosure include, but are not limited to, aspartic acid, glutamic acid, alanine, arginine, omithine, citrulline, asparagine, carnitine, cysteine, glutamine, glycine, histidine, lysine, isoleucine, leucine, methionine, N-phenylalanine, proline, serine, taurine, threonine, tryptophan, tyrosine, and valine. It may be preferable for amino acids to be basic amino acids comprising an additional amine function optionally included in a ring or in a ureido function. Such basic amino acids may preferably be chosen from those corresponding to formula (IV) below: HHL & R --CH"—"CH * (IV) in which R represents a group chosen from:

[0194]

[0195]

[0196]

[0197]

[0198]

[0199] -(CH2)3-NH2, -(CH2)2-NH2, -(CH2)2-NH-CO-NH2, and Compounds corresponding to formula (IV) include histidine, lysine, arginine, ornithine, and citrulline. The organic alkalizing agent can be chosen from among the heterocyclic organic amines. In addition to histidine, which has already been mentioned among the amino acids, the following compounds can be cited in particular: pyridine, piperidine, imidazole, triazole, tetrazole, and benzimidazole. The organic alkalizing agent may also be selected from amino acid dipeptides. Examples of amino acid dipeptides that may be used in this disclosure include camosine, anserine, and baleine.

[0200] The organic alkalizing agent may also be selected from compounds comprising a guanidine function. As amines of this type that may be used in the present disclosure, in addition to arginine, which has already been cited as an amino acid, creatine, creatinine, 1,1-dimethylguanidine, 1,1-diethylguanidine, glycocyamine, metformin, agmatine, N-amidinoalanine, 3-guanidinopropionic acid, 4-guanidinobutyric acid and 2-([amino(imino)methyl]amino)ethane-l-sulfonic acid.

[0201] In a preferred embodiment of this disclosure, the organic alkalizing agent may be selected from amino acids, preferably basic amino acids, and more preferably arginine, lysine, histidine, or mixtures thereof. Even more preferably, the organic alkalizing agent may be arginine.

[0202] Examples of hybrid compounds that may be cited include salts of the amines mentioned above with acids such as carbonic acid or hydrochloric acid. Guanidine carbonate or monoethanolamine hydrochloride may be used in particular.

[0203] The pH correcting agent may be present in an amount of 0.01% by weight or more, preferably 0.05% by weight or more and, more preferably, 0.1% by weight or more, relative to the total weight of the composition.

[0204] The pH correcting agent may be present in an amount of 15% by weight or less, preferably 10% by weight or less and, more preferably, 5% by weight or less, relative to the total weight of the composition.

[0205] The pH correcting agent may be present in an amount from 0.01% to 15% by weight, preferably from 0.05% to 10% by weight and, more preferably, from 0.1% to 5% by weight or less, relative to the total weight of the composition.

[0206] It is preferable that the composition according to this disclosure has a pH of 4.5 or more, and more preferably of 5 or more.

[0207] It is preferable that the composition according to this disclosure has a pH of 6.5 or less and, more preferably, of 6 or less.

[0208] It is preferable that the composition according to this disclosure has a pH of 4.5 to 6.5 and, more preferably, of 5 to 6.

[0209] The pH of the composition means the pH of the aqueous phase of the composition according to this disclosure.

[0210] It may be preferable that at least one buffer or buffering agent also be used, such as the pH correcting agent, in combination with the acidifying agent and / or the alkalizing agent, in order to stabilize the pH of the composition according to this disclosure.

[0211] As a buffer, any of the commonly known buffers may be used. For example, salts of acids or bases, preferably salts of acids Weak or weak bases can be used. For example, sodium citrate or sodium lactate can be used as a buffer if citric acid or lactic acid is used as the acidifying agent.

[0212] Cosmetically acceptable support system

[0213] Cosmetic compositions comprise a cosmetically acceptable carrier system. The term “cosmetically acceptable” means a carrier compatible with any keratinous substrate and, for the purposes hereof, includes water and, optionally, water-based solvents, subject to any exclusions disclosed herein.

[0214] Cosmetic compositions may include any constituent normally used in the intended topical application and administration. These may include, but are not limited to, water, solvents, polyols, compounds (i.e., those described by the International Federation of Societies of Cosmetic Chemistry, for example in Analysis and Quality of Cosmetic Raw Materials, Volume I: Hydrocarbons, Glycerides, Waxes and Other Esters (Redwood Books, 1994), pigments, fillers, silicones, surfactants, thickeners, gelling agents, preservatives and mixtures thereof in all proportions. Usage methods

[0215] This disclosure also relates to processes for using the cosmetic compositions described herein. For example, the cosmetic compositions may be used in a process that includes applying the cosmetic compositions to human skin. In some cases, the composition is applied to the face. Furthermore, the cosmetic composition may be used in processes for depigmenting, lightening, and / or bleaching keratinous materials, preferably skin, comprising the step of applying the composition to the keratinous substance according to the compositions described herein. The aforementioned processes are non-therapeutic.

[0216] The cosmetic composition can be applied once a day, twice a day, or more than once or twice a day. In some cases, the composition is applied in the evening before bedtime. In other cases, the compositions are applied in the morning. In still other cases, the composition can be applied immediately after washing the skin. The compositions can be used once, or for a series of days, weeks, or months. For example, the compositions can be used daily for a period of 1, 2, 3, 4, 5, 6, 7, 8 weeks or more, or months.

[0217] This disclosure also relates to the non-therapeutic cosmetic process for depigmenting, lightening and / or bleaching keratinous materials, preferably the skin, including the step of: applying the compositions described in this document to the keratinous substance.

[0218] These and other aspects of the invention are described in more detail in the detailed description of the invention.

[0219] This disclosure describes examples of embodiments according to general inventive concepts and is not intended to limit the scope of the invention in any way. Indeed, the invention as described in the document is broader than, and not limited by, the examples of embodiments presented herein, and the terms used herein have their full ordinary meaning. EXAMPLES

[0220] An implementation of this disclosure is provided by means of the following examples. The following examples are intended to explain certain aspects of the technology without being limited by their nature. Example 1

[0221] Example 1: Synthesis of compound 20

[0222] Compound 20 is synthesized as disclosed in Example 2 of patent EP3 390 363. Example 2 Inventive compositions:

[0223] The inventive and comparative compositions were prepared according to the following general procedure:

[0224] Water-soluble raw materials were added to the main tank and dissolved. Polymers were then added and mixed until well dispersed. The batch was heated to 75 °C. In a separate tank, fatty compounds, silicones, emulsifiers, and / or enhancers were mixed and heated to 75 °C. The mixture from the separate tank was added to the main tank, ensuring thorough homogenization. Once well emulsified, the batch was cooled to room temperature, and active substances and fillers were added.

[0225] Inventive compositions

[0226] [Tableauxô] Inventive Example 1 Inventive Example 2 Inventive Example 3 Inventive Example 4 Inventive Example 5 INCI US Thiopyridinone-type compound 0.5 0.5 0.5 0.5 0.5 Ethylhexyl Methoxycrylene 1.0 1.0 0 1.0 3.0 Diethylhexyl Syringylide nemalonate 0.9 0.9 0.9 1.8 0 Fatty compounds 7.5 4.3 7.7 4.3 4.3 Filler 0.4 1.0 0.4 0 0 Polymer 1.6 1.6 1.6 1.6 1.6 Preservative 0.6 0.6 0.6 0.6 0.6 Silicon 4.6 4.6 6.1 4.6 4.6 Solvent 7.0 9.0 7.0 9.0 9.0 Surfactant 8.7 8.7 8.7 8.7 8.7 Active ingredient 1.8 1.4 1.8 1.7 1.7 Vitamin 10.3 10.3 10.3 10.3 10.3 Water QSQSQSQSQS

[0227] Comparative compositions

[0228] [Tables?] Comp. Ex. 1 Comp. Ex. 2 INCI US Thiopyridine-type compound 0.5 0.5 Ethylhexyl Methoxycrylene 0 0 Diethylhexyl Syringylidenemalonate 0 0 Butyl methoxydibenzoylmethane 0 0 Ethylhexyl Salicylate 0 0 Terephthalylidene Diethylamphor Sulfonic Acid 0 0 Octocrylene 0 0 Homosalate 0 0 Mineral sunscreen 0 0 Fatty compounds 3.0 7.7 Filler 0.5 0.4 Polymer 1.5 1.6 Preservative 0.6 0.6 Silicon 1.5 6.1 Solvent 20.3 4.0 Surfactant 2.7 8.7 Active ingredient 5.6 1.8 Vitamin 6.0 10.3 Water QSQS Example 3

[0229] Inventive examples 1 and several comparative examples were tested for photostability. The photostability of the inventive and comparative examples was evaluated following the procedure described below.

[0230] First, the amount of thiopyridinone (THP)-type compound in the formula is determined by HPLC / UV. A specific amount of the formula is distributed uniformly on a PMMA plate to produce a layer of approximately 2 mg / cm² (n=4 plates). All plates are exposed to UVA light until a dose of 5 J / cm², corresponding to the average daily UV dose, is reached using a solar simulator instrument. The plates are removed, and a solvent is used to wash off the formulation film. The thiopyridinone-like compound is then extracted. This extract is subsequently quantified for the thiopyridinone-like compound concentration using HPLC / UV. The percentage of photostability is given as follows: % Thiopyridinone-like compound after UVA exposure / % Initial thiopyridinone-like compound x 100.

[0231] The results are presented in Table 8 below.

[0232] Photostability results

[0233] [Tables8] Examples % THP*** remaining after UV test UV Filters (%) Inventive Enhancer Mixture** (%) Comp. Ex. 1 6% 0% 0% Worst-case scenario (no filters or enhancers) Comp. Ex. 2 63% 0% 0% Better stability than Ex. Comp. 1; but can still be improved. Inventive Ex. 1 81% 0% 1% ethylhexyl methoxycrylene + 1% diethylhexyl syringylidene malonate Inventive; not OTC*, and better stability Inventive Ex. 2 87% 0% 1% diethylhexyl syringylidene malonate Inventive; Not OTC*, and better stability. Ex. Inventory 3 90% 0% 1% ethylhexyl methoxycrylene + 2% diethylhexyl syringylidene malonate. Inventory; not OTC*, and better stability. Ex. Inventory 4 86% 0% 3% ethylhexyl methoxycrylene. Inventory; not OTC*, and better stability.

[0234] *= Available for sale without a prescription

[0235] **= Ethylhexylmethoxycrylene and diethylhexyl syringylidene malonate

[0236] ***=thiopyridinone type compound

[0237] The photostability of the compound of thiopyridinone-type formulations containing UV enhancers was evaluated using the photostability protocol described above.

[0238] It was observed that the composition containing the enhancers exhibited photostability at the same level as or greater than that of the thiopyridinone type compound.

[0239] It has been shown that the thiopyridinone-type compound was stabilized when the compositions contained one or two enhancers such as ethylhexyl methoxycrylene and diethyl syringylidene malonate

[0240] The inventors discovered how the stability of the thiopyridinone-type compound when exposed to light is enhanced by incorporating a booster or mixture of boosters such as ethylhexyl methoxycrylene and diethylethyl syringylidene malonate.

[0241] Although the disclosure has been described with reference to described embodiments, it will be understood by those skilled in the art that various modifications can be made and equivalents can be substituted for elements thereof without departing from the scope of the disclosure. Furthermore, numerous modifications can be made to adapt a particular situation or subject matter to the teachings of the disclosure without departing from its essential scope. Therefore, it is intended that the disclosure will not be limited to the particular embodiment disclosed as being the best envisaged means of carrying out that disclosure, but that the disclosure will include all embodiments falling within the scope of the claims.

[0242] The term “INCI” is an abbreviation for International Nomenclature of Cosmetic Ingredients, which is a system of names provided by the International Nomenclature Committee of the Personal Care Products Council to describe the ingredients of personal care products.

[0243] “At least one”, as used herein, means one or more and thus includes individual components as well as mixtures / combinations.

[0244] The transitional terms "including," "consisting essentially of," and "consisting of," when used in the claims, in their original and amended forms, define the scope of the claim with respect to any additional unspecified elements or steps, if any, which are excluded from the scope of the claim(s). The term "including" is intended to be inclusive or broad and does not exclude any additional, unspecified element, process, step, or material. The expression "consisting of" excludes any element, step, or material other than those specified in the claim and, in the latter case, impurities ordinarily associated with the specified material(s). The expression "consisting essentially of" limits the scope of a claim to the specified elements, steps, or materials and to those that do not materially affect the fundamental and novel features of the claimed disclosure.All the materials and processes described in this document that embody this disclosure may, in other embodiments, be defined more specifically by any of the transitional terms "including", "consisting essentially of" and "consisting of".

[0245] The terms "free" and "devoid" indicate that no reliably measurable excluded material is present in the composition, typically 0% by weight, relative to the total weight of the composition. The term "essentially free" means that, although it is preferable for no excluded material to be present in the composition, it is possible to have very small amounts of the excluded material in the composition of the disclosure, provided that such amounts do not materially affect the advantageous properties of the composition. In particular, "essentially free" means that the excluded material may be present in the composition in an amount of less than about 0.1% by weight, relative to the total weight of the composition.

[0246] All percentages and ratios are calculated by weight unless otherwise stated. All percentages are calculated relative to the total composition unless otherwise stated. In general, unless expressly stated otherwise in this document, "weight" or "quantity" as used in this document with respect to the percentage of an ingredient means the quantity of raw material comprising the ingredient, the raw material being described in this document as comprising less than and up to 100% of the ingredient's activity. Therefore, the percentage by weight of an active substance in a composition is represented as the quantity of raw material containing the active substance that is used and may or may not reflect the final percentage of the active substance, the final percentage of the active substance depending on the percentage by weight of the active substance in the raw material.

[0247] The terms "percent by weight" and "% by weight" may be used interchangeably and mean the percentage by weight, relative to the total weight of a composition, article, or material, except as may be specified with respect to, for example, a phase or system that is a component of a composition, article, or material. All ranges and quantities stated herein are intended to include subranges and quantities using any disclosed point as a boundary. Thus, a range of "1% to 10%, such as 2% to 8%, such as 3% to 5%" is intended to encompass ranges of "1% to 8%", "1% to 5%", "2% to 10%", and so on. All figures, quantities, ranges, etc., are intended to be modified by the term "approximately", whether or not expressly stated.Similarly, a given range of "approximately 1% to 10%" is intended to have its 1% and 10% limits modified by the term "approximately". Furthermore, it is understood that when a quantity of a component is given, it is assumed to mean the quantity of active ingredient, unless expressly stated otherwise.

[0248] Although the numerical ranges and parameters presenting the general scope of disclosure are approximations, unless otherwise indicated, the values The numerical values ​​presented in the specific examples are reported as accurately as possible. However, every numerical value inherently contains some error resulting from the standard deviation observed in their respective test measurements. The following example serves to illustrate one implementation of this disclosure but is not intended to be limiting.

Claims

Demands

1. Cosmetic composition including: i) a) at least one compound selected from compounds of formula (I) and the tautomer of formula (!') below or their salts; and their optical, racemate, and / or solvated isomers such as hydrates, alone or in mixtures: Formulas (I) and (I') in which: -RI designates a radical chosen from: a) a hydrogen atom; b) a linear saturated C1-C10 or C3-C10 branched alkyl group optionally substituted by one or more groups, which may be identical or different, chosen from: i) -O-R3 ii) -S-R3; - R2 denotes a radical chosen from: a) a hydrogen atom; b) a linear saturated hydrocarbon group in Cl-Cl2 or branched in C3-C12 or cyclic in C3-C8, optionally substituted by one or more groups, which may be identical or different, chosen from: i) -O-R3 ii) -S-R3 iii) -C(O)-O-R3 ; (iv) an aryl group in C5-C12, optionally substituted by one or more hydroxyl groups and / or by one or more alkoxy radicals in C1-C8; c) an aryl group at C5-C12, optionally substituted by one or more hydroxyl groups and / or by one or more alkoxy radicals at C1-C8 -R3 designates a radical chosen from: a) hydrogen atony; b) a linear saturated C1-C10 or C3-C10 branched alkyl group; ii) a mixture of ethylhexyl methoxycrylene and diethyl syringylidene malonate; and wherein: - compound i) is present from 0.5 to 3% by weight, relative to the total weight of the cosmetic composition; - ethylhexyl methoxycrylene is present from 0.3 to 2.8% by weight, relative to the total weight of the cosmetic composition; - diethyl syringylidene malonate is present from 0.3 to 2.8% by weight, relative to the total weight of the cosmetic composition; and the combination of a mixture of ethylhexyl methoxycrylene and diethyl syringylidene malonate improves the photostability of thiopyridinone compounds; said cosmetic composition is free of UV filters.

2. Composition according to any one of the preceding claims, wherein compound ii) improves the photostability of thiopyridinone-type compounds.

3. Composition according to any one of the preceding claims, wherein the pH is from about 4.5 to about 6.5, preferably from about 5 to about 6.

4. A method for photo-stabilizing thiopyridinone compounds with a mixture of ethylhexylmethoxycrylene and diethyl syringylidene malonate comprising combining thiopyridinone compounds with a mixture of ethylhexylmethoxycrylene and diethyl syringylidene malonate, thereby improving the photo-stability of thiopyridinone compounds.

5. A skin treatment method comprising applying a cosmetic composition according to claim 1 to the skin.

6. A non-therapeutic cosmetic process for depigmenting, lightening and / or bleaching keratinous materials, preferably skin, comprising the step of applying the composition according to claim 1 to the keratinous substance.