STABILIZATION OF THIOPYRIDINONE COMPOUND AND COMPOSITION COMPRISING SAME

Abstract

STABILIZATION OF THIOPYRIDINONE COMPOUND AND COMPOSITION COMPRISING SAME The present invention relates to a composition comprising: (1) at least one thiopyridinone compound; (2) at least one pH correcting agent, and (3) water, wherein the pH of the composition is 4.5 to 6.5. The present invention can provide a composition including (1) thiopyridinone compound(s) with increased stability of the (1) thiopyridinone compound(s) over time, particularly even when the composition is maintained for a relatively long period under an elevated temperature. Figure for abstract: None

Description

Title of the invention: STABILIZATION OF THIOPY-RIDINONE COMPOUND AND COMPOSITION COMPRISING IT Technical field

[0001] The present invention relates to the stabilization of a thiopyridinone compound in a composition including the thiopyridinone compound.

[0002] CONTEXT OF ART

[0003] At various times in their lives, some people notice the appearance on their skin, and more particularly on their face and hands, of darker and / or more colored spots, which give a heterogeneous appearance to their skin. These spots are in particular due to a high concentration of melanin in the keratinocytes located on the surface of the skin.

[0004] The use of harmless topical depigmentation substances having good efficacy is more particularly desired for the purpose of treating pigmentation spots.

[0005] For example, arbutin, niacinamide and kojic acid are known as skin depigmenting agents.

[0006] On the other hand, document WO2017 / 102349 discloses a novel depigmenting or whitening agent, i.e., a thiopyridinone compound. The thiopyridinone compound can exhibit strong depigmenting or whitening effects by reducing the production of melanin. DISCLOSURE OF THE INVENTION

[0007] However, it has been discovered that a thiopyridinone compound tends to destabilize in a composition over time, particularly when the composition including the thiopyridinone compound is maintained for a relatively long period under an elevated temperature.

[0008] Thus, an objective of the present invention is to provide a composition including one or more thiopyridinone compounds with increased stability of the thiopyridinone compound(s) over time, in particular when the composition is maintained for a relatively long period under an elevated temperature.

[0009] The above objective can be achieved by a composition comprising:

[0010] (1) at least one compound chosen from the compounds of formula (I) below, the tautomers of formula (T) below, their salts, solvates, such as hydrates, their optical isomers, their racemates, and their mixtures:

[0011] (I)(D

[0012] in which

[0013] Ri denotes a radical chosen from

[0014] a) a hydrogen atom, and

[0015] b) a linear saturated C1-C10 or C3-C10 branched alkyl group optionally substituted by one or more groups, which may be the same or different, chosen from

[0016] i) -O-R3, and

[0017] ii) -S-R3,

[0018] and

[0019] R2 denotes a radical chosen from

[0020] a) a hydrogen atom,

[0021] b) a linear or branched C3-Ci2 or cyclic C3-C8 saturated hydrocarbon group, optionally substituted by one or more groups, which may be the same or different, chosen from

[0022] i) -O-R3,

[0023] ii) -S-R3,

[0024] iii) -C(O)-O-R3, and

[0025] iv) a C5-C12 aryl group, optionally substituted by one or more hydroxyls and / or by one or more C1-C8 alkoxy radicals, and

[0026] c) a C5-C12 aryl group, optionally substituted by one or more hydroxyls and / or by one or more C1-C8 alkoxy radicals

[0027] in which

[0028] R3 denotes a radical chosen from

[0029] a) a hydrogen atom, and

[0030] b) a linear C1-C10 or branched C3-C10 saturated alkyl group;

[0031] (2) at least one pH correction agent; and

[0032] (3) water,

[0033] in which

[0034] the pH of the composition is from 4.5 to 6.5, and preferably from 5 to 6.

[0035] It may be preferable that:

[0036] Ri of formula (I) and (!') represents a hydrogen atom;

[0037] or

[0038] Ri of formula (I) and (!') represents a linear (C1-C10) or branched (C3-C10) alkyl group, in particular a linear (C1-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 not substituted.

[0039] It may be preferable that:

[0040] R2 of formula (I) and (I') represents a hydrogen atom;

[0041] or

[0042] R2 of formula (I) and (I') represents a linear (C1-C10) or branched (C3-C10) alkyl group, in particular a linear (C1-C6) or branched (C3-C6) alkyl group, such as methyl, ethyl, n-pentyl, n-nonyl, isobutyl, more preferably methyl or ethyl; said alkyl group of R2 being unsubstituted.

[0043] It may be preferable that:

[0044] R2 of formula (I) and (I1) represents a linear or branched (C1-C10) alkyl group, in particular a linear 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 chosen from i), ii), iii) and iv) as above, preferably said alkyl group being substituted by one or two groups chosen from i), ii) and iii), more preferably by one or two groups chosen from i) and iii), better substituted by a group iii) such as carboxy.

[0045] It may be preferable that:

[0046] R2 of formula (I) and (I') represents a cycloalkyl group (C3-C8), preferably a cycloalkyl group (C5-C7) such as cyclohexyl;

[0047] or

[0048] R2 of formula (I) and (I1) represents a C5-C12 aryl group optionally substituted by one or more hydroxyls and / or by one or more C1-C8 alkoxy radicals, preferably a phenyl group in particular unsubstituted.

[0049] It may be preferable that:

[0050] R3 of formula (I) and (I') represents a hydrogen atom;

[0051] or

[0052] R3 of formula (I) and (I') represents a linear C1-C10 or branched C3-C10 saturated alkyl group; in particular a linear (C1-C6) alkyl group or a branched (C3-C6) alkyl group, preferably a (C1-C4) alkyl group such as the methyl group.

[0053] It may be more preferable that:

[0054] Ri of formula (I) and (!') represents a radical chosen from

[0055] a) a hydrogen atom, and

[0056] b) a linear C1-C6 or C3-C6 branched saturated alkyl group optionally substituted by one or more groups, which may be the same or different, chosen from

[0057] i) -O-R3, and

[0058] ii) -S-R3,

[0059] preferably optionally substituted with one or more groups i);

[0060] R2 of formula (I) and (!') represents a radical chosen from

[0061] a) a hydrogen atom, and

[0062] b) a linear C1-C10 or branched C3-C10 or cyclic C3-C8 or C5-C6 saturated hydrocarbon group, optionally substituted by one or more groups, which may be identical or different, chosen from:

[0063] i) -O-R3,

[0064] ii) -S-R3,

[0065] iii) -C(O)-O-R3, and

[0066] iv) a phenyl group optionally substituted by one or more hydroxyls and / or by one or more C1-C4 alkoxy radicals such as methoxy,

[0067] preferably substituted by one or more groups chosen from i) and iii), preferably iii) such as carboxy; and

[0068] R3 of formula (I) and (!') represents a radical chosen from

[0069] a) a hydrogen atom, and

[0070] b) a linear C1-C6 or branched C3-C6 saturated alkyl group,

[0071] preferentially, the compounds of formula (I) and the tautomer (!), their salts, solvates, such as hydrates, their optical isomers, their racemates, and their mixtures, have the following meanings:

[0072] Ri of formula (I) and (!') represents a radical chosen from:

[0073] a) a hydrogen atom, and

[0074] b) a linear saturated C1-C4 or C3-C4 branched alkyl group optionally substituted by one or more groups, which may be the same or different, chosen from i) -OR3>more preferably unsubstituted;

[0075] R2 of formula (I) and (!') represents a radical chosen from

[0076] a) a hydrogen atom, and

[0077] b) a linear C1-C10 or branched C3-C10 or cyclic C3-C8 or C5-C6 saturated hydrocarbon group, optionally substituted by one or more groups, which may be the same or different, chosen from

[0078] i) -O-R3,

[0079] iii) -C(O)-O-R3, and

[0080] iv) a C5-C12 aryl group, optionally substituted by one or more hydroxyls and / or by one or more C1-C4 alkoxy radicals; and

[0081] R3 of formula (I) and (!') represents a radical chosen from:

[0082] a) a hydrogen atom;

[0083] b) a linear C1-C4 or branched C3-C4 saturated alkyl group such as methyl or ethyl.

[0084] The (1) compound may be chosen from compounds 1 to 24 below, their tautomers, their salts, their solvates such as hydrates, their optical isomers, their racemates, and their mixtures, in particular compounds 1, 2, 4, 6, 7, 9, 11, 12, 14, 15, 16, 17, 18, 19, 20 or 21, more particularly 1, 9, 16, 18, 19, 20 or 21, preferably 18, 19, 20 or 21, more preferably 20:

[0085] [Tables 1] No. Structure Chemical name 1 H N-ethyl-2-thioxo-1,2-dihydropyridine -3-carboxamide 2 AV' ' HN-------A. N-methyl-2-thioxo-1,2-dihydropyridi ne-3-carboxamide 3 b N-octyl-2-thioxo-1,2-dihydropyridine -3-carboxamide 4 (X^ N-benzyl-2-thioxo-1,2-dihydropyridi ne-3-carboxamide 5 / / \\ Ks—Y x) ZA <\ / A™™ / ç y----->-----: A N-phenyl-2-thioxo-1,2-dihydropyridi ne-3-carboxamide 6 xuu N-cyclohexyl-2-thioxo-1,2-dihydrop yridine- 3 -carboxamide 7 N- [2-(4-methoxyphenyl)ethyl] -2-thio xo-1,2-dihydropyridine-3-carboxami de 8 J’*x -'^-x À $ vS N-(2-méthylpropyl)-2-thioxo-1,2-dih ydropyridine-3-carboxamide 9 ■A 'A 'A’'''" "A-A ‘'V" N-pentyl-2-thioxo-1,2-dihydropyridi ne-3-carboxamide 10 N-nonyl-2-thioxo-1,2-dihydropyridin e-3-carboxamide 11 ' / ' \ Z P \ / / / FA / """"', O Z X ''^ Am N-(2-hydroxyéthyl)-2-thioxo-1,2-dih ydropyridine-3-carboxamide 12 Fz "A Fm N,N-diéthyl 2-mercaptonicotinamide 13 N-éthyl-N-(2-hydroxyéthyl)-2-thioxo -1,2-dihydropyridine-3-carboxamide 14 'MM' N-(2,3-dihydroxypropyl)-2-thioxo-1, 2-dihydropyridine-3-carboxamide 15 ■ L 1 C'* H N-(1,3-dihydroxypropan-2-yl)-2-thio xo-1,2-dihydropyridine-3-carboxami of 16 s ÇH. ss / - N-[(2-thioxo-1,2-dihydropyridin-3-yl )carbonyl]ethyl alaninate 17 T ' ,--¼. N-[(2-thioxo-1,2-dihydropyridin-3-yl )carbonyl]phenyl ethyl alaninate 18 ï X$< ;. Ethyl N-methyl-N-[(2-thioxo-1,2-dihydropyridin-3-yl)carbonyl]glycinate 19 f ï 1 Jï Ethyl N-[(2-thioxo-1,2-dihydropyridin-3-yl )carbonyl]glycinate 20 r->. A .-Y- ' 0 L * ï <4 N-[(2-thioxo-1,2-dihydropyridin-3-yl )carbonyl]glycine 21 i / ^33333^7* VJX \ / / / \ ut ac,^- / N-methyl-N-[(2-thioxo-1,2-dihydropyridin-3-yl)carbonyl]glycine 22 nr •-XX " ' e-3-carboxamide

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093] The amount of the (1) compound(s) in the composition according to the present invention may be from 0.01% to 10% by weight, preferably from 0.05% to 5% by weight, and more preferably from 0.1% to 3% by weight, relative to the total weight of the composition. The (2) pH correction agent may be chosen from acidifying agents, basifying agents, and mixtures thereof. The amount of the (2) pH correction agent(s) in the composition according to the present invention may be 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, relative to the total weight of the composition. The amount of (3) water in the composition according to the present invention may be from 20% to 99% by weight, preferably from 30% to 95% by weight, and more preferably from 40% to 90% by weight, relative to the total weight of the composition. The composition according to the present invention may be intended to whiten a keratinous substance, preferably the skin. The present invention also relates to a cosmetic process, preferably a bleaching process, for a keratinous substance, preferably the skin, comprising the step: application to the keratinous substance of the composition according to the present invention. Another aspect of the present invention is a use of (2) at least one agent pH correction in a composition comprising (1) at least one compound chosen from the compounds of formula (I) below, the tautomers of formula (I1) below, their salts, their solvates, such as hydrates, their optical isomers, their racemates, and their mixtures:

[0094] (I) (!')

[0095] in which

[0096] Ri denotes a radical chosen from

[0097] a) a hydrogen atom, and

[0098] b) a linear saturated C1-C10 or C3-C10 branched alkyl group optionally substituted by one or more groups, which may be the same or different, chosen from

[0099] i) -O-R3, and

[0100] ii) -S-R3,

[0101] and

[0102] R2 denotes a radical chosen from

[0103] a) a hydrogen atom,

[0104] b) a linear or branched C3-Ci2 or cyclic C3-C8 saturated hydrocarbon group, optionally substituted by one or more groups, which may be the same or different, chosen from

[0105] i) -O-R3,

[0106] ii) -S-R3,

[0107] iii) -C(O)-O-R3, and

[0108] iv) a C5-C12 aryl group, optionally substituted by one or more hydroxyls and / or by one or more CrC8 alkoxy radicals, and

[0109] c) a C5-C12 aryl group, optionally substituted by one or more hydroxyls and / or by one or more CrC8 alkoxy radicals

[0110] in which

[0111] R3 denotes a radical chosen from

[0112] a) a hydrogen atom, and

[0113] b) a linear C1-C10 or branched C3-C10 saturated alkyl group

[0114] in order to regulate the pH of the composition so that it is from 4.5 to 6.5 in order to stabilize the (1) compound(s). Best mode for carrying out the invention

[0115] After diligent research, the inventors have discovered that it is possible to provide a composition including a thiopyridinone compound or thiopyridinone compounds with increased stability of the thiopyridinone compound(s) over time, particularly even when the composition is maintained for a relatively long period under an elevated temperature.

[0116] Thus, the composition according to the present invention comprises:

[0117] (1) at least one compound chosen from the compounds of formula (I) below, the tautomers of formula (I1) below, their salts, solvates, such as their hydrates, their optical isomers, their racemates, and their mixtures (hereinafter, the compound is designated by "thiopyridinone compound"):

[0118] (I)(D

[0119] in which

[0120] Ri denotes a radical chosen from

[0121] a) a hydrogen atom, and

[0122] b) a linear saturated C1-C10 or C3-C10 branched alkyl group optionally substituted by one or more groups, which may be the same or different, chosen from

[0123] i) -O-R3, and

[0124] ii) -S-R3,

[0125] and

[0126] R2 denotes a radical chosen from

[0127] a) a hydrogen atom,

[0128] b) a linear or branched C3-Ci2 or cyclic C3-C8 saturated hydrocarbon group, optionally substituted by one or more groups, which may be the same or different, chosen from

[0129] i) -O-R3,

[0130] ii) -S-R3,

[0131] iii)-C(O)-O-R3, and

[0132] iv) a C5-C12 aryl group, optionally substituted by one or more hydroxyls and / or by one or more CrC8 alkoxy radicals, and

[0133] c) a C5-C12 aryl group, optionally substituted by one or more hydroxyls and / or by one or more CrC8 alkoxy radicals

[0134] in which

[0135] R3 denotes a radical chosen from

[0136] a) a hydrogen atom, and

[0137] b) a linear C1-C10 or branched C3-C10 saturated alkyl group;

[0138] (2) at least one pH correction agent; and

[0139] (3) water,

[0140] in which

[0141] the pH of the composition is from 4.5 to 6.5, and preferably from 5 to 6.

[0142] The composition according to the present invention can show increased stability of (1) thiopyridinone compound it contains.

[0143] In other words, the composition according to the present invention can increase the stability of the compound (1) thiopyridinone contained therein. The term "stability" of the compound (1) thiopyridinone can be determined by the change in the amount of the compound (1) thiopyridinone in the composition according to the present invention over a certain period. Increased "stability" means that the change in the amount of the compound (1) thiopyridinone over time is more limited.

[0144] The composition according to the present invention can show increased stability of the compound (1) thiopyridinone contained therein, even when the composition is maintained for a relatively long period, such as two weeks under a high temperature, such as 55°C.

[0145] Therefore, the composition according to the present invention can be stored for a long period of time, even under hot conditions.

[0146] Furthermore, the increased stability of the (1) thiopyridinone compound may provide improved or enhanced bioavailability of the (1) thiopyridinone compound which may function as a depigmenting or whitening agent. Therefore, the composition according to the present invention may provide improved or enhanced depigmentation or whitening effects.

[0147] Hereinafter, the composition, use and others according to the present invention will be described in detail.

[0148] [Composition]

[0149] The composition according to the present invention comprises:

[0150] (1) of at least one thiopyridinone compound;

[0151] (2) at least one pH correction agent; and

[0152] (3) water,

[0153] and

[0154] the pH of the composition is 4.5 to 6.5.

[0155] The (1) thiopyridinone compound, the (2) pH correcting agent, and (3) water, as well as the other features of the composition according to the present invention will be explained below.

[0156] (Thiopyridinone compound)

[0157] The composition according to the present invention comprises (1) at least one thiopyridinone compound. Two or more (1) thiopyridinone compounds may be used in combination. Thus, a single type of (1) thiopyridinone compound or a combination of different types of (1) thiopyridinone compounds may be used.

[0158] The (1) thiopyridinone compound is chosen from the compounds of formula (I) below, the tautomers of formula (I1) below, their salts, their solvates, such as hydrates, their optical isomers, their racemates, and their mixtures:

[0159] (I) (!')

[0160] in which

[0161] Ri denotes a radical chosen from

[0162] a) a hydrogen atom, and

[0163] b) a linear saturated C1-C10 or C3-C10 branched alkyl group optionally substituted by one or more groups, which may be the same or different, chosen from

[0164] i) -O-R3, and

[0165] ii) -S-R3,

[0166] and

[0167] R2 denotes a radical chosen from

[0168] a) a hydrogen atom,

[0169] b) a linear C1-C12 or branched C3-C12 or cyclic C3-C8 saturated hydrocarbon group, optionally substituted by one or more groups, which may be the same or different, chosen from

[0170] i) -O-R3,

[0171] ii)-S-R3,

[0172] iii) -C(O)-O-R3, and

[0173] iv) a C5-C12 aryl group, optionally substituted by one or more hydroxyls and / or by one or more CrC8 alkoxy radicals, and

[0174] c) a C5-C12 aryl group, optionally substituted by one or more hydroxyls and / or by one or more CrC8 alkoxy radicals

[0175] in which

[0176] R3 denotes a radical chosen from

[0177] a) a hydrogen atom, and

[0178] b) a linear C1-C10 or branched C3-C10 saturated alkyl group.

[0179] Hereinafter, for the purposes of the present invention, and unless otherwise indicated:

[0180] a "saturated, linear CrCi2 or branched C3-Ci2" hydrocarbon group is equivalent to a "linear (CrCi2) or branched (C3-Ci2) alkyl group" which corresponds to a saturated, linear CrCi2 or branched C3-Ci2 hydrocarbon group, preferably a linear C1-Ci0 or branched C3-Ci0 hydrocarbon group, and more preferably a linear C1-C6 or branched C3-C6 hydrocarbon group; Preferably, the linear or branched groups may be chosen from methyl, ethyl, propyl, isopropyl, butyl, isobutyl and tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl groups; More preferably, the saturated, linear or branched alkyl groups may be chosen from methyl, ethyl, propyl, isopropyl, butyl, isobutyl and tert-butyl, pentyl, hexyl, heptyl and octyl groups, such as methyl, ethyl, n-pentyl, n-nonyl, isobutyl;

[0181] - a “C3-C8 cyclic” saturated hydrocarbon group is a monocycloalkyl group or bicyclic containing from 3 to 8 carbon atoms, and in particular is a monocyclic C5 to C7 cycloalkyl group such as a cyclohexyl group,

[0182] - an "alkoxy radical" is an alkyloxy radical whose alkyl radical is a radical linear or branched in C1-C16, and preferentially a C1-C8 hydrocarbon radical;

[0183] - when the alkoxy group is optionally substituted, this implies that the group alkyl is optionally substituted as defined above;

[0184] - an “aryl” group represents a carbon-based, monocyclic or bi cyclic, fused or not, comprising from 5 to 12 carbon atoms, preferably from 6 to 10 carbon atoms, and in which at least one cycle is aromatic; preferably, the aryl radical is a phenyl, biphenyl, naphthyl group, more preferably a phenyl group;

[0185] - the term “at least one” is equivalent to the term “one or more”; and

[0186] - the term "inclusive" for a concentration range means that the limits of this range are included in the defined range.

[0187] The salts of the compounds of formula (I), (I'), (II) or (II1) as defined below include the conventional non-toxic salts of said compounds, such as those formed from an organic or inorganic acid or from an organic or inorganic base.

[0188] As salts of the compounds of formula (I), (I'), (II) or (II'), mention may be made of:

[0189] the salts obtained by addition of the compound of formula (I) or (II) to:

[0190] 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;

[0191] or

[0192] an organic base such as a primary, secondary or tertiary alkylamine, for example triethylamine or butylamine. This primary, secondary or tertiary alkylamine may comprise one or more nitrogen and / or oxygen atoms and may therefore comprise, for example, one or more alcohol functions. Mention may be made in particular of 2-amino-2-methylpropanol, ethanolamine, triethanolamine, 2-dimethylaminopropanol, 2-amino-2-(hydroxymethyl)-1,3-propanediol and 3-(dimethylamino)propylamine.

[0193] Mention may also be made of amino acid salts, for example lysine, arginine, guanidine, glutamic acid and aspartic acid. Advantageously, the salts of the compounds of formula (I) or (II) (when they comprise a carboxy group) may be chosen from alkali or alkaline earth metal salts such as sodium, potassium, calcium or magnesium salts and ammonium salts.

[0194] An “organic or inorganic acid salt” is more particularly chosen from salts chosen from a salt derived from i) hydrochloric acid HCl, ii) hydrobromide 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.

[0195] Acceptable solvates of the compounds described in the specification 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.

[0196] The optical isomers are in particular the enantiomers and the diastereoisomers.

[0197] Compound (I') is the tautomeric form of compound (I) when a tautomeric equilibrium exists according to the following scheme: (I) (D

[0198] According to one embodiment of the present invention, Ri represents a hydrogen atom.

[0199] According to one embodiment of the present invention, the formula (I) and (!') represents a linear (C1-C10) or branched (C3-C10) alkyl group, in particular a linear (C1-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 not substituted.

[0200] According to one embodiment of the present invention, R2 represents a hydrogen atom.

[0201] According to one embodiment of the present invention, R2 represents a linear (C1-C10) or branched (C3-C10) alkyl group, in particular a linear (C1-C6) or branched (C3-C6) alkyl group, such as methyl, ethyl, n-pentyl, n-nonyl, isobutyl, more preferably methyl or ethyl; said alkyl group of R2 not being substituted.

[0202] According to one embodiment of the present invention, R2 of formula (I) and (!') represents a linear (C1-C10) or branched (C3-C10) alkyl group, in particular a linear (C1-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 chosen from i), ii), iii) and iv) as defined above. Preferably, said alkyl group being substituted by one or more groups chosen from i), ii) and iii), more preferably by one or more groups chosen from i) and iii), better substituted by a group iii) such as carboxy.

[0203] Another variant for the radical R2 is that said alkyl group is substituted by a group iv) in particular substituted by a phenyl group.

[0204] According to another embodiment of the invention, R2 represents a cycloalkyl group (C3-C8, preferably a cycloalkyl group (C5-C7) such as cyclohexyl.

[0205] According to another embodiment of the invention, R2 represents a C 5-C 12 aryl group optionally substituted by one or more hydroxyls and / or by one or more C 1-C 8 alkoxy radicals, preferably a phenyl group in particular unsubstituted.

[0206] According to one embodiment, R3 represents a hydrogen atom.

[0207] According to another embodiment, R3 represents a saturated, linear C1-C10 or branched C3-C10 alkyl group; in particular a linear (C1-C6) or branched (C3-C6) alkyl group, preferably an alkyl group (C1-C4) such as the group methyl.

[0208] 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 as a mixture

[0209] have the following meanings:

[0210] Ri denotes a radical chosen from

[0211] a) a hydrogen atom, and

[0212] b) a linear C1-C6 or C3-C6 branched saturated alkyl group optionally substituted by one or more groups, which may be the same or different, chosen from

[0213] i) -O-R3, and

[0214] ii) -S-R3,

[0215] preferably optionally substituted with one or more groups i);

[0216] R2 denotes a radical chosen from

[0217] a) a hydrogen atom;

[0218] b) a linear C1-C10 or branched C3-C10 or cyclic C3-C8 or C5-C6 saturated hydrocarbon group, optionally substituted by one or more groups, which may be the same or different, chosen from:

[0219] i) -O-R3,

[0220] ii) -S-R3,

[0221] iii) -C(O)-O-R3, and

[0222] iv) a phenyl group optionally substituted by one or more hydroxyls and / or by one or more C1-C4 alkoxy radicals such as methoxy,

[0223] preferably substituted by one or more groups chosen from i) and iii), preferably iii) such as carboxy; and

[0224] R3 denotes a radical chosen from

[0225] a) a hydrogen atom, and

[0226] b) a linear C1-C6 or branched C3-C6 saturated alkyl group

[0227] 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 as a mixture

[0228] have the following meanings:

[0229] Ri denotes a radical chosen from

[0230] a) a hydrogen atom, and

[0231] b) a linear saturated C1-C4 or C3-C4 branched alkyl group optionally substituted by one or more groups, which may be the same or different, chosen from i) -OR3jplus preferably unsubstituted;

[0232] R2 denotes a radical chosen from

[0233] a) a hydrogen atom; and

[0234] b) a linear C1-C10 or branched C3-C10 or cyclic C3-C8 or C5-C6 saturated hydrocarbon group, optionally substituted by one or more groups, which may be the same or different, chosen from:

[0235] i) -O-R3,

[0236] iii) -C(O)-O-R3,

[0237] iv) a C5-C12 aryl group, optionally substituted by one or more hydroxyls and / or by one or more C1-C4 alkoxy radicals; and

[0238] R3 denotes a radical chosen from

[0239] a) a hydrogen atom, and

[0240] b) a linear C1-C4 or branched C3-C4 saturated alkyl group such as methyl or ethyl.

[0241] Preferably, the compounds of formula (I) and the tautomer (P) or their salts, their optical isomers, racemates, and / or solvates such as hydrates and their derivatives, alone or as a mixture

[0242] have the following meanings:

[0243] Ri is a hydrogen atom; and

[0244] R2 denotes a radical chosen from

[0245] a) a hydrogen atom, and

[0246] b) a saturated hydrocarbon group, linear in C1-C5 or branched in C3-C5 or cyclic in C3-C8 such that C5-C6 may be identical or different, chosen from v) -C(O)-O-R3, preferably substituted by a group iii) -C(O)-O-R3; R2 is even more preferably a saturated hydrocarbon group, linear in C1-C4 or branched in C3-C4 substituted by a group iii) -C(O)-OR3; and

[0247] R3 denotes a radical chosen from

[0248] a) a hydrogen atom, and

[0249] b) a linear C1-C4 or branched C3-C4 saturated alkyl group such as methyl or ethyl.

[0250] According to another preferred embodiment, the compounds of formula (I) and the tautomer (P) are chosen from the compounds of formula (II) below as well as their tautomers of formula (IP) below, their salts, their solvates and their optical isomers, and their racemates, alone or as a mixture: [0251 ] [T ableaux2] 0 TO, x ü L X.

[0252] in formulas (II) and (II') R1 and R3 have the same meaning as R1 and R3 in the compounds of formula (I) and (I') and X denotes an alkylene radical -(CH2)n- with n being an integer ranging inclusively from 1 to 10, preferably from 1 to 6, more preferably from 1 to 4, such that 1, preferably R3 represents a hydrogen atom.

[0253] Preferably, 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:

[0254] [Tables3] No. Structure Chemical Name CAS No. 1 H N-ethyl-2-thioxo-1,2-dihydropyridine-3-carbo xamide 91859-75-5 2 / / XX N-methyl-2-thioxo-1,2-dihydropyridine-3-car boxamide 91859-74-4 3 •'"■'■'s T' p N-octyl-2-thioxo-1,2-dihydropyridine-3-carbo xamide 91859-77-7 4 XI| ! N-benzyl-2-thioxo-1,2-dihydropyridine-3-carb oxamide 91859-79-9 5 y--------H<_;-------\> s. / AX N-phenyl-2-thioxo-1,2-dihydropyridine-3-carb oxamide 104857-16-1 6 y N-cyclohexyl-2-thioxo-1,2-dihydropyridine-3-carboxamide 91859-78-8 7 N-[2-(4-methoxyphenyl)ethyl]-2-thioxo-1,2-dihydropyridine-3-carbo xamide 923682-88-6 8 x : ->•:. N-(2-méthylpropyl)-2-t hioxo-1,2-dihydropyrid ine-3-carboxamide 1100027-79- 9 9 v-'^X • .'"^x N-pentyl-2-thioxo-1,2-dihydropyridine-3-carb oxamide 330667-57-7 10 '1 il 11 :<" N-nonyl-2-thioxo-1,2-dihydropyridine-3-carb oxamide 1031149-44- 6 11 NX H . À. "OH N-(2-hydroxyéthyl)-2-t hioxo-1,2-dihydropyrid ine-3-carboxamide 12 sx^ 'TJ ^.; N,N-diéthyl 2-mercaptonicotinamid e 13 M‘ N-éthyl-N-(2-hydroxyé thyl)-2-thioxo-1,2-dihy dropyridine-3-carboxa mide 14 $ x\s îj N-(2,3-dihydroxypropy l)-2-thioxo-1,2-dihydro pyridine-3-carboxamid e 15 hs 4 N-(1,3-di hydroxypropa n-2-yl)-2-thioxo-1,2-di hydropyridine-3-carbo xamide 16 o £K. c'' >•;■* x^'' Ethyl N-[(2-thioxo-1,2-dihydropyridin-3-yl)carbonyl]alaninate 17 Ethyl N-[(2-thioxo-1,2-dihydropyridin-3-yl)carbonyl]phenyl alaninate 18 y Ethyl N-methyl-N-[(2-thioxo -1,2-dihydropyridin-3-yl)carbonyl]glycinate 19 Ethyl N-[(2-thioxo-1,2-dihydropyridin-3-yl)carbonyl]glycinate 20 4 Ethyl N-[(2-thioxo-1,2-dihydropyridin-3-yl)carbonyl]glycine 21 □ A ex xr N ■ £ H N-methyl-N-[(2-thioxo -1,2-dihydropyridin-3-yl)carbonyl]glycine 22 ...J' 0 N,N-bis(2-hydroxyethyl)-2-thioxo-1,2-dihydropyridine-3-carboxamide e 23 Kr ' JH Ï4 N-(3-methoxypropyl)-2-thioxo-1,2-dihydropyridine-3-carboxamide 24 :-:Sr N-butyl-2-thioxo-1,2-d ihydropyridine-3-carbo xamide

[0255] Among these compounds, the following compounds are more particularly preferred:

[0256] [Tables4] No. Structure Chemical Name CAS No. 1 N-Ethyl-2-thioxo-1,2-dihydropyridine-3-carboxamide 91859-75-5 2 \ / \\ ¢: Xx N-methyl-2-thioxo-1, 2-dihy dropyridine- 3 -carboxamide 91859-74-4 4 b ']x * t JH N-benzyl-2-thioxo-1, 2-dihy dropyridine- 3 -carboxamide 91859-79-9 6 ' xv ■ N-cyclohexyl-2-thiox o-1,2-dihydropyridine -3-carboxamide 91859-78-8 7 G .-<£■*' VV'* AAU N- [2- (4-methoxyphen yl)ethy 1] -2-thioxo-1,2 -dihy dropyridine- 3 -ca rboxamide 923682-88-6 9 X' XA" 'A 11 | 'Al'*"' H 12 ay 1 i "'CH; N,N-diethyl 2-mercaptonicotinami de 14 IJ il N-(2,3-dihydroxyprop yl)-2-thioxo-1,2-dihy dropyridine-3-carboxa mide 15 x■* an-2-yl)-2-thioxo-1,2-dihydropyridine-3-car boxamide 16 > AN. ethyl 18 N-methyl-N-[(2-thiox [(o-1,2-dihydropyridin-3-yl)carbonyl]glycinate ethyl 19 N-[(2-thioxo-1,2-dihydropyridin-3-yl)carbonyl]glycinate ethyl 20 1 .. H N-[(2-thioxo-1,2-dihy dropyridin-3-yl)carbo nyljglycine 21 n H N-methyl-N-[(2-thiox o-1,2-dihydropyridin-3-yl)carbonyl]glycine

[0257] more preferably, among these compounds, the following compounds are more particularly preferred:

[0258] [Tables5] No. Structure Chemical Name CAS No. 1 .-O- N-ethyl-2-thioxo-1,2-dihydropyridine-3-car boxamide 91859-75-5 9 x"xx,. zs. N-pentyl-2-thioxo-1,2 -dihy dropyridine- 3 -ca rboxamide 330667-57-7 16 y* V Ethyl N-[(2-thioxo-1,2-dihy dropyridin-3-yl)carbo nyl]alaninate 18 k, «. Ethyl N-methyl-N-[(2-thiox o-1,2-dihydropyridin-3-yl)carbonyl]glycinate 19 >! Ethyl N-[(2-thioxo-1,2-dihy dropyridin-3-yl)carbo nyl]glycinate 20 O _<X jL --x z" (i T r ï N > 1 N-[(2-thioxo-1,2-dihy dropyridin-3-yl)carbo nyljglycine 21 nm CH. CH H N-methyl-N-[(2-thiox o-1,2-dihydropyridin-3-yl)carbonyl]glycine

[0259]

[0260]

[0261] Even more preferably, among these compounds, the following compounds are more particularly preferred: [Tableauxô] No. Structure Chemical Name CAS No. 18 fxSrY Ethyl N-methyl-N-[(2-thioxo-1,2-dihydropyridin-3-yl)carbonyl]glycinate 19 G II T * Il Ethyl N-[(2-thioxo-1,2-dihydropyridin-3-yl)carbonyl]glycinate 20 ( / o=\. iï fi \, \^J N-[(2-thioxo-1,2-dihydropyridin-3-yl)carbonyl]glycine 21 (X' t 'f / rf: " " \ z \ "A N-methyl-N-[(2-thioxo-1,2-dihydropyridin-3-yl)carbonyl]glycine In a most preferred embodiment, the compound according to the present invention is as follows:

[0262]

[0263]

[0264]

[0265]

[0266]

[0267]

[0268]

[0269] [Paintings?] 20 CX " <• N-[(2-thioxo-1,2-dihy dropyridin-3-yl)carbo nyl]glycine All of the above compounds can be obtained by a chemical process known to those skilled in the art, from commercially available reagents. The (1) thiopyridinone compound may be prepared in accordance with the process described, for example, in EP-A-3390363 or WO 2017 / 102349, which are incorporated herein by reference. The (1) thiopyridinone compound may be an active ingredient or an active compound in cosmetic or dermatological products. The term "active" ingredient or compound as used herein means an ingredient or compound that has a cosmetic or dermatological active property, such as antioxidant, whitening, UV-filtering, and antibacterial effects. The (1) thiopyridinone compound used in the present invention may function as a depigmenting, bleaching, or whitening agent, and thus the composition according to the present invention may be used as a whitening product or as a cosmetic composition for a whitening keratinous substance. The (1) thiopyridinone compound can be used as a depigmenting, bleaching or whitening agent for the skin, body hair, eyelashes or hair, as well as lips and / or nails, and preferably for the skin, in particular for removing pigmentation or senescence spots, and / or as an antitanning agent. The amount of the (1) thiopyridinone compound(s) in the composition according to the present invention may be 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. On the other hand, the amount of the (1) thiopyridinone compound(s) in the composition according to the present invention may be 10% by weight or less, preferably 5% by weight or less, and more preferably 3% by weight or less, relative to the total weight of the composition. The amount of the (1) thiopyridinone compound(s) in the composition according to the present invention may range from 0.01% to 10% by weight, preferably from 0.05% to 5% by weight, more preferably from 0.1% to 3% by weight, relative to the total weight of the composition.

[0270] (pH correction agent)

[0271] The composition according to the present invention comprises (2) at least one pH correcting agent (pH corrector). Two or more pH correcting agents may be used in combination. Thus, a single type of pH correcting agent or a combination of different types of pH correcting agents may be used.

[0272] The (2) pH correction agent is different from the (1) thiopyridinone compound.

[0273] As (2) pH correction agent, at least one agent may be used acidifying agent and / or at least one basifying agent (alkaline agent).

[0274] The acidifying agent may be a monovalent or polyvalent acid, such as divalent.

[0275] The 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, lactic acid, as well as sulfonic acids.

[0276] The basifying agent may be a monovalent or polyvalent base, such as divalent.

[0277] Basifying agents can be mineral (inorganic) or organic, or hybrid.

[0278] The mineral basifying agents may be chosen from aqueous 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.

[0279] The organic basifying agents may be chosen from 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 function of greatest basicity. In addition, the organic amines do not comprise any alkyl or alkenyl fatty chain comprising more than ten carbon atoms.

[0280] The organic basifying agent may be chosen, for example, from alkanolamines, oxyethylenated and / or oxypropylenated ethylenediamines, amino acids and amine compounds of formula (III) below:

[0281] in which

[0282] W represents a divalent C1-C6 alkylene radical optionally substituted by one or more hydroxyl groups or a C1-C6 alkyl radical, and optionally interrupted by one or more heteroatoms such as O and N, and

[0283] Rx, Ry, Rz, and Rt, which may be the same or different, represent an atom of hydrogen or a C1-C6 alkyl, C1-C6 hydroxyalkyl, or C1-C6 aminoalkyl radical.

[0284] Examples of amine compounds of formula (III) which may be mentioned include 1,3-diaminopropane, 1,3-diamino-2-propanol, spermine and spermidine.

[0285] The term "alkanolamine" designates an organic amine comprising a primary, secondary or tertiary amine function, and one or more linear or branched CrC8 alkyl groups carrying one or more hydroxyl radicals.

[0286] Alkanolamines such as monoalkanolamines, dialkanolamines or trialkanolamines comprising one to three identical or different C1-C4 hydroxyalkyl radicals may be suitable for the present invention. Among the compounds of this type, mention may be made of monoethanolamine (MEA), diethanolamine, triethanolamine, monoisopropa-nolamine, 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.

[0287] The amino acids which can 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 the carboxylic acid, sulfonic acid, phosphonic acid or phosphoric acid functions. The amino acids can be in neutral or ionic form.

[0288] As amino acids that can be used in the present invention, mention may in particular be made of 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.

[0289] It may be preferable that the amino acids are basic amino acids comprising an additional amine function optionally included in a ring or in a ureido function.

[0290] Such basic amino acids may preferably be chosen from those corresponding to formula (IV) below:

[0291] in which

[0292] R represents a group chosen from:

[0293] -(CH2)3-NH2,

[0294] -(CH2)2-NH2,

[0295] -(CH2)2-NH-CO-NH2, and

[0296] Compounds corresponding to formula (IV) include histidine, lysine, arginine, ornithine and citrulline.

[0297] The organic basifying agent may be chosen from organic amines of heterocyclic type. In addition to histidine which has already been mentioned in the amino acids, mention may in particular be made of pyridine, piperidine, imidazole, triazole, tetrazole and benzimidazole.

[0298] The organic basifying agent may also be chosen from amino acid dipeptides. As amino acid dipeptides which may be used in the present invention, mention may in particular be made of carnosine, anserine and balein.

[0299] The organic basifying agent may also be chosen from compounds comprising a guanidine function. As amines of this type which may be used in the present invention, in addition to arginine, which has already been mentioned as an amino acid, mention may in particular be made of 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-1-sulfonic acid.

[0300] In a preferred embodiment of the present invention, the organic basifying agent may be chosen from amino acids, preferably basic amino acids, and more preferably arginine, lysine, histidine or mixtures thereof. Even more preferably, the organic basifying agent may be arginine.

[0301] Hybrid compounds that may be mentioned include salts of the aforementioned amines with acids such as carbonic acid or hydrochloric acid. Guanidine carbonate or monoethanolamine hydrochloride may in particular be used.

[0302] The (2) 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.

[0303] The (2) pH correction 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.

[0304] The (2) pH correction agent may be present in an amount ranging 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.

[0305] It is preferable that the composition according to the present invention has a pH of 4.5 or more, and more preferably of 5 or more.

[0306] It is preferable that the composition according to the present invention has a pH of 6.5 or less, and more preferably 6 or less.

[0307] It is preferable that the composition according to the present invention has a pH of 4.5 to 6.5, and more preferably of 5 to 6.

[0308] The pH of the composition means the pH of the aqueous phase of the composition according to the present invention. The pH can be measured in accordance with JIS Z 8802 (2011).

[0309] It may be preferable that at least one buffer or buffering agent is also used, as (2) pH correcting agent, in combination with the acidifying agent and / or the basifying agent, in order to stabilize the pH of the composition according to the present invention.

[0310] As a buffer, any of the commonly known buffers may be used. For example, salts of acids or bases, preferably salts of weak acids or weak bases, may be used. For example, sodium citrate or sodium lactate may be used as a buffer, if citric acid or lactic acid is used as the acidifying agent.

[0311] (Water)

[0312] The composition according to the present invention comprises (3) water.

[0313] The amount of (3) water in the composition according to the present invention may be 20% by weight or more, preferably 30% by weight or more, and more preferably 40% by weight or more, relative to the total weight of the composition.

[0314] On the other hand, the amount of (3) water in the composition according to the present invention may be 99% by weight or less, preferably 95% by weight or less, and more preferably 90% by weight or less, relative to the total weight of the composition.

[0315] The amount of (3) water in the composition according to the present invention may be from 20% to 99% by weight, preferably from 30% to 95% by weight, and more preferably from 40% to 90% by weight, relative to the total weight of the composition.

[0316] (Optional additives)

[0317] The composition according to the present invention may also comprise any optional additive(s) usually used in the field of cosmetics, chosen for example from solvents, antioxidants, chelating agents, cosmetic active ingredients other than ingredient (1), such as oils, preservatives, and their mixtures.

[0318] It is a matter of routine operation for a person skilled in the art to adjust the nature and quantity of the above optional additives which may be present in the composition according to the present invention, such that the desired cosmetic properties are not affected.

[0319] As solvents, mention may be made of one or more cosmetically acceptable organic solvents, which may be alcohols: in particular monovalent alcohols such as ethyl alcohol, isopropyl alcohol, benzyl alcohol, phenylethyl alcohol; diols such as ethylene glycol, propylene glycol, butylene glycol; other polyols such as glycerol, sugar, sugar alcohols; and ethers such as monomethyl, monoethyl and monobutyl ethers of ethylene glycol, monomethyl, monoethyl and monobutyl ethers of propylene glycol and monomethyl, monoethyl and monobutyl ethers of butylene glycol.

[0320] The organic solvent(s) may be present at a concentration of 0.01% to 30% by weight, preferably of 0.1% to 20% by weight, and more preferably of 1% to 10% by weight, relative to the total weight of the composition.

[0321] [Preparation]

[0322] The composition according to the present invention can be prepared by mixing the essential and optional ingredients described above in a conventional manner.

[0323] For example, the composition according to the present invention can be prepared by a process comprising the following steps

[0324] the mixture

[0325] (1) of at least one thiopyridinone compound;

[0326] (2) at least one pH correction agent; and

[0327] (3) of water.

[0328] It is possible to further mix any of the optional ingredients.

[0329] The mixing may be carried out at any temperature such as room temperature (e.g., 20-25°C, preferably 25°C), preferably at a temperature of 30°C or higher, preferably 40°C or higher, and more preferably 50°C or higher. It is preferable to carry out the mixing further with any of the optional ingredients described above, such as a pH correcting agent.

[0330] The form of the composition according to the present invention is not particularly limited, and may take various forms such as a W / O emulsion, an O / W emulsion, a gel, a solution, or the like. It is preferable that the composition according to the present invention is in the form of an emulsion, preferably an O / W emulsion, and more preferably an O / W gel emulsion.

[0331] [Cosmetic process]

[0332] The composition according to the present invention can be used as a cosmetic or dermatological composition, preferably as a cosmetic composition, and more preferably as a cosmetic composition for a keratinous material. As keratinous material, mention may be made of the skin, the scalp, the hair, the mucous membranes such as the lips and the nails.

[0333] The composition according to the present invention can be used as a depigmentation, bleaching or whitening product for a keratinous material such as the skin. In particular, the composition according to the present invention can be used as a whitening product.

[0334] The composition according to the present invention may preferably be intended for application to a keratinous material such as the skin, the scalp and / or the lips, preferably the skin.

[0335] Thus, the composition according to the present invention can be used for a cosmetic process for a keratinous material, preferably the skin. In one embodiment, the present invention relates to a cosmetic process, preferably a bleaching process, for a keratinous material, preferably the skin, comprising the step of applying to the keratinous material the composition according to the present invention.

[0336] The composition according to the present invention can be used as a topical cosmetic composition in the form of a lotion, a milky lotion, a cream, a gel, a paste, a serum, a mousse or a spray.

[0337] [Use]

[0338] The present invention also relates to a use of (2) at least one pH correction agent in a composition comprising (1) at least one compound chosen from the compounds of formula (I) below, the tautomers of formula (I) below, their salts, solvates, such as their hydrates, their optical isomers, their racemates, and their mixtures:

[0339] (I) (!')

[0340] in which

[0341] Ri denotes a radical chosen from

[0342] a) a hydrogen atom, and

[0343] b) an optionally branched linear C1-C10 or C3-C10 saturated alkyl group substituted by one or more groups, which may be the same or different, chosen from

[0344] i) -O-R3, and

[0345] ii) -S-R3,

[0346] and

[0347] R2 denotes a radical chosen from

[0348] a) a hydrogen atom,

[0349] b) a linear or branched C3-Ci2 or cyclic C3-C8 saturated hydrocarbon group, optionally substituted by one or more groups, which may be the same or different, chosen from

[0350] i) -O-R3,

[0351] ii)-S-R3,

[0352] iii) -C(O)-O-R3, and

[0353] iv) a C5-C12 aryl group, optionally substituted by one or more hydroxyls and / or by one or more CrC8 alkoxy radicals, and

[0354] c) a C5-C12 aryl group, optionally substituted by one or more hydroxyls and / or by one or more CrC8 alkoxy radicals

[0355] in which

[0356] R3 denotes a radical chosen from

[0357] a) a hydrogen atom, and

[0358] b) a linear C1-C10 or branched C3-C10 saturated alkyl group

[0359] in order to regulate the pH of the composition so that it is from 4.5 to 6.5 in order to stabilize the (1) compound(s).

[0360] The term “stabilize” has the same meaning as enhancing stability.

[0361] The use according to the present invention can increase the stability of the thio-pyridinone compound (1) in the composition comprising it.

[0362] Therefore, the use according to the present invention can enable a composition comprising the thiopyridinone compound (1) to be stored for a long period of time, and in particular even under hot conditions.

[0363] The above explanations relating to (1) thiopyridinone compound and (2) pH correcting agent for the compositions according to the present invention may also apply to those used in the use according to the present invention.

[0364] The composition in the use according to the present invention may include any of the optional ingredients as explained above for the compositions according to the present invention.

[0365] EXAMPLES

[0366] The present invention will be described in more detail with the aid of examples. However, these examples should not be interpreted as limiting the scope of the present invention. [Examples 1-3 and Comparative Example 1]

[0367] [Preparation]

[0368] Each of the compositions according to Examples 1 to 3 and Comparative Example 1 was prepared by mixing the ingredients listed in Table 8. The numerical values ​​for the amounts of the ingredients are all based on "% by weight" as active ingredients.

[0369] [Tables8] Ingredients Ex. 1 Ex. 2 Ex. 3 Comp. Ex. 1 Water qsp 100 qsp 100 qsp 100 qsp 100 Glycerin 5.2 5.2 5.2 5.2 Butylene Glycol 4.4 4.4 4.4 4.4 Preservatives 1.3 1.3 1.3 1.3 N-[(2-thioxo-l,2-dihydropyridin-3-yl)carbonyl] glycine 1.0 1.0 1.0 1.0 Potassium Hydroxide 0.52 - - 0.54 Sodium Hydroxide - 0.70 - - Arginine - - 0.70 - PH 5.8 5.8 5.8 7.0 Compound Thiopyridinone Remaining rate (%) 95 95 95 41 Stability Very good Very good Very good Poor

[0370] N-[(2-thioxo-1,2-dihydropyridin-3-yl)carbonyl]glycine (2-MERCAPTONICOTINOYL GLYCINE): Compound 20 [0371 ] [Evaluations]

[0372] (pH)

[0373] The pH at 25°C of each of the compositions according to Examples 1 to 3 and Comparative Example 1 was measured as follows.

[0374] Equipment:

[0375] 1. pH meter; Laqua F-71 (Horiba)

[0376] 2. pH electrodes; 9615S-10D (Horiba)

[0377] 3. pH standard solutions (Horiba)

[0378] 4. internal pH probe solution (Horiba)

[0379] Procedures:

[0380] 1. The internal solution charging ports of the pH meter have been opened, and internal solutions were provided around the electrodes.

[0381] 2. Calibration was carried out using standard solutions at pH 9, 7 and 4.

[0382] 3. The electrodes were washed with deionized water.

[0383] 4. The protective cap of one of the electrodes (glass electrode) has been removed, and the electrodes were immersed in each of the compositions according to Examples 1 to 3 and Comparative Example 1.

[0384] 5. The pH was recorded after the pH value had stabilized.

[0385] The results are shown in the "pH" row of Table 8.

[0386] (Remaining level of thiopyridinone compound)

[0387] The amount of thiopyridinone compound in each of the compositions according to Examples 1-3 and Comparative Example 1 was measured by HPLC-UV assay at the following time point.

[0388] Moment (1) Just after the preparation of the composition (T0)

[0389] Time (2) 2 weeks after preparation, where the composition was kept in a sealed container and protected from light at 55°C

[0390] The details of the HPLC-UV assay are as follows.

[0391] Apparatus / Reagents

[0392] [Tables9] Ultra performance LC (UPLC) HPLC system RP18 HPLC column, 1.7 pm, 2.1 mm x 100 mm Eluent A 0.1% Phosphoric Acid in water Eluent B Methanol

[0393] HPLC conditions

[0394] [Tables10] UV Detector 296 nm Column temp. 30°C Flow rate 0.4 mL / min Injection volume 1 pL Mobile phase Gradient mode A: 0.1% Phosphoric Acid in water B: Methanol

[0395] The remaining level of thiopyridinone compound was determined by the following equation:

[0396] Remaining rate of thiopyridinone compound (%) =

[0397] Amount of thiopyridinone compound at time (2) / Amount of thiopyridinone compound at time (1)

[0398] The results are shown in the line "Remaining level of thiopyridinone compound (%)" in Table 8.

[0399] The remaining level of thiopyridinone compound was also categorized in accordance with the following criteria:

[0400] Very good 90% or more

[0401] Good 50% or more and less than 90%

[0402] Bad: less than 50%

[0403] The results are shown in the "stability" row of Table 8.

[0404] (Results)

[0405] The compositions according to Examples 1 to 3, each of which included a thiopyridinone compound and a pH correcting agent for regulating the pH of the composition from 4.5 to 6.5, were more stable, even under elevated temperature, such that most of the thiopyridinone compound remained, than the composition according to Comparative Example 1 which had a pH of more than 6.5.

Claims

Claims

1. Use of (2) at least one pH correcting agent in a cosmetic composition comprising (1) at least one compound selected from the compounds of formula (I) below, the tautomers of formula (!') below, the salts thereof, the solvates, such as hydrates, thereof, the optical isomers thereof, the racemates thereof, and the mixtures thereof: (i) (D in which Ri denotes a radical chosen from a) a hydrogen atom, and (b) a linear saturated C1-C10 or C3-C10 branched alkyl group optionally substituted by one or more groups, which may be the same or different, selected from i) -O-R3, and ii) -S-R3, And R2 denotes a radical chosen from a) a hydrogen atom, (b) a linear or branched C3-C12 or cyclic C3-C8 saturated hydrocarbon group optionally substituted by one or more groups, which may be the same or different, chosen from i) -O-R3, ü) -S-R3, iii) -C(O)-O-R3, and iv) a C5-C12 aryl group, optionally substituted by one or more hydroxyls and / or by one or more C1-C8 alkoxy radicals, and (c) a C5-C12 aryl group, optionally substituted by one or more hydroxyls and / or by one or more C1-C8 alkoxy radicals in which R3 denotes a radical chosen from a) a hydrogen atom, and b) a saturated linear CrCio or branched C3-Ci0 alkyl group; and (3) water, in order to regulate the pH of the composition to be from 4.5 to 6.5, and preferably from 5 to 6, in order to stabilize the (1) compound(s).

2. Use according to claim 1, wherein the composition comprises at least one compound (1) selected from the compounds of formula (I), the tautomers of formula (!'), the salts thereof, the solvates, such as hydrates, of these, the optical isomers thereof, the racemates thereof, and the mixtures thereof, wherein: R 1 of formula (I) and (!') represents a hydrogen atom; or R 1 of formula (I) and (!') represents a linear (C 1 -C 10 ) or branched (C 3 -C 10 ) alkyl group, in particular a linear (C 1 -C 6 ) or branched (C 3 -C 6 ) alkyl group, such as methyl, ethyl, n-pentyl, n-nonyl, isobutyl, more preferably ethyl, in particular said alkyl group of R 1 is not substituted.

3. Use according to claim 1 or 2, wherein the composition comprises at least one compound (1) chosen from the compounds of formula (I), the tautomers of formula (!'), the salts thereof, the solvates, such as hydrates, of these, the optical isomers thereof, the racemates thereof, and the mixtures thereof, wherein: R2 of formula (I) and (!') represents a hydrogen atom; or R2 of formula (I) and (!') represents a linear (C1-C10) or branched (C3-C10) alkyl group, in particular a linear (C1-C6) or branched (C3-C6) alkyl group, such as methyl, ethyl, n-pentyl, n-nonyl, isobutyl, more preferably methyl or ethyl; said alkyl group of R2 being unsubstituted.

4. Use according to claim 1 or 2, wherein the composition comprises at least one compound (1) chosen from the compounds of formula (I), the tautomers of formula (!'), the salts thereof, the solvates, such as hydrates, of these, the optical isomers thereof, the racemates thereof, and the mixtures thereof, wherein:

5.

6.

7. R2 of formula (I) and (I1) represents a linear or branched (C1-C10) alkyl group, in particular a linear or branched (C1-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 chosen from i), ii), iii) and iv) as above, preferably said alkyl group being substituted by one or two groups chosen from i), ii) and iii), more preferably by one or two groups chosen from i) and iii), better substituted by a group iii) such as carboxy. Use according to claim 1 or 2, wherein the composition comprises at least one compound (1) chosen from the compounds of formula (I), the tautomers of formula (!), the salts thereof, the solvates, such as hydrates, of these, the optical isomers thereof, the racemates thereof, and the mixtures thereof, wherein: R2 of formula (I) and (!') represents a cycloalkyl group (C3-C8), preferably a cycloalkyl group (C5-C7) such as cyclohexyl; Or R2 of formula (I) and (I1) represents a C5-C12 aryl group optionally substituted by one or more hydroxyls and / or by one or more C1-C8 alkoxy radicals, preferably a phenyl group in particular unsubstituted. Use according to any one of claims 1 to 5, wherein the composition comprises at least one compound (1) chosen from the compounds of formula (I), the tautomers of formula (!), the salts thereof, the solvates, such as hydrates, of these, the optical isomers thereof, the racemates thereof, and the mixtures thereof, wherein: R3 of formula (I) and (!') represents a hydrogen atom; or R3 of formula (I) and (!) represents a linear C1-C10 or branched C3-C10 saturated alkyl group; in particular a linear (C1-C6) alkyl group or a branched (C3-C6) alkyl group, preferably a (C1-C4) alkyl group such as the methyl group. Use according to any one of claims 1 to 6, in which the composition comprises at least one compound (1) chosen from the compounds of formula (I), the tautomers of formula (!'), the salts thereof, the solvates, such as the hydrates, of these, the optical isomers thereof, racemates thereof, and mixtures thereof, wherein: Ri of formula (I) and (!') represents a radical chosen from a) a hydrogen atom, and (b) a linear C1-C6 or C3-C6 branched saturated alkyl group optionally substituted by one or more groups, which may be the same or different, chosen from i) -O-R3, and ii) -S-R3, preferably optionally substituted by one or more groups i); R2 of formula (I) and (!') represents a radical chosen from a) a hydrogen atom, and (b) a linear C1-C10 or branched C3-C10 or cyclic C3-C8 or C5-C6 saturated hydrocarbon group, optionally substituted by one or more groups, which may be the same or different, chosen from: i) -O-R3, ii) -S-R3, iii) -C(O)-O-R3, and iv) a phenyl group optionally substituted by one or more hydroxyls and / or by one or more C1-C4 alkoxy radicals such as methoxy, preferably substituted by one or more groups chosen from i) and iii), preferably iii) such as carboxy; and R3 of formula (I) and (!') represents a radical chosen from a) a hydrogen atom, and b) a linear saturated C1-C6 or branched C3-C6 alkyl group, preferably, the compounds of formula (I) and the tautomer (!'), their salts, solvates, such as hydrates, their optical isomers, their racemates, and their mixtures, have the following meanings: R1 of formula (I) and (!') represents a radical chosen from: a) a hydrogen atom, and b) a linear C1-C4 or branched C3-C4 saturated alkyl group optionally substituted by one or more groups, which may be the same or different, chosen from i) -OR3jplus preferably unsubstituted; R2 of formula (I) and (!') represents a radical chosen from a) a hydrogen atom, and

8. (b) a linear C1-C10 or branched C3-C10 or cyclic C3-C8 or C5-C6 saturated hydrocarbon group, optionally substituted by one or more groups, which may be the same or different, chosen from i) -O-R3, iii) -C(O)-O-R3, and iv) a C5-C12 aryl group, optionally substituted by one or more hydroxyls and / or by one or more C1-C4 alkoxy radicals; and R3 of formula (I) and (!') represents a radical chosen from: a) a hydrogen atom; (b) a linear C1-C4 or branched C3-C4 saturated alkyl group such as methyl or ethyl. Use according to any one of claims 1 to 7, wherein: compound (1) is selected from compounds 1 to 24 below, tautomers thereof, salts thereof, solvates, such as hydrates, thereof, optical isomers thereof, racemates thereof, and mixtures thereof, in particular compounds 1, 2, 4, 6, 7, 9, 11, 12, 14, 15, 16, 17, 18, 19, 20 or 21, more particularly 1, 9, 16, 18, 19, 20 or 21, preferably 18, 19, 20 or 21, and more preferably 20: [Tableaux 1] N° Structure Nom chimique 1 H N-éthyl-2-thioxo-1,2-dihydrop yridine- 3 -carboxamide 2 N-méthyl-2-thioxo-1,2-dihydr opyridine-3-carboxamide 3 ■ N-octyl-2-thioxo-1,2-dihydrop yridine- 3 -carboxamide 4 :-x x'"x [j s T '^ H N-benzyl-2-thioxo-1,2-dihydro pyridine-3-carboxamide 5 .,—.... — / / X JT / : ■>____ / $ V- N-phényl-2-thioxo-1,2-dihydro pyridine-3-carboxamide 6 N-cyclohexyl-2-thioxo-1,2-dih ydropyridine-3-carboxamide 7 N-[2-(4-méthoxyphényl)éthyl] -2-thioxo-1,2-dihydropyridine-3-carboxamide 8 $ 'tî N-(2-méthylpropyl)-2-thioxo-1 ,2-dihydropyridine-3-carboxa mide 9 N-pentyl-2-thioxo-1,2-dihydro pyridine-3-carboxamide 10 h .. N-nonyl-2-thioxo-1,2-dihydro pyridine-3-carboxamide 11 VsX H h XY 'V x-x î "<3H x'¥ XV H N-(2-hydroxyéthyl)-2-thioxo-1 ,2-dihydropyridine-3-carboxa mide 12 a X?Z " '-y 1 X X ' Ç. H N,N-diéthyl 2-mercaptonicotinamide 13 Q h x î r \ 1 j: | ; \ x$ '•*'■>: N-éthyl-N-(2-hydroxyéthyl)-2-thioxo-1,2-dihydropyridine-3-c arboxamide 14 r r N-(2,3-dihydroxypropyl)-2-thi oxo-1,2-dihydropyridine-3-car boxamide 15 . . ..h..... Jx "P .K H N-( 1,3-dihydroxypropan-2-yl)-2-thioxo-1,2-dihydropyridine-3-carboxamide 16 $ ck-, H [ " XV' S^“ h¥ N-[(2-thioxo-1,2-dihydropyridi n-3-yl)carbonyl]alaninate d'éthyle 17 N-[(2-thioxo-1,2-dihydropyridi n-3-yl)carbonyl]phényl alaninate d'éthyle 18 '''kx^-‘a' ;fv'v N-méthyl-N-[(2-thioxo-l,2-dih ydropyridin-3-yl)carbonyl]gly cinate d'éthyle 19 "S N-[(2-thioxo-1,2-dihydropyridi n-3-yl)carbonyl]glycinate d'éthyle 20 ■x,, H N-[(2-thioxo-1,2-dihydropyridi n-3-yl)carbonyl]glycine 21 Lt ^:; H N-méthyl-N-[(2-thioxo-l,2-dih ydropyridin-3-yl)carbonyl]gly cine 22 i] N,N-bis(2-hydroxyéthyl)-2-thi oxo-1,2-dihydropyridine-3-car boxamide 23 hr\ ÿ 1 S o T '“ N-(3-méthoxypropyl)-2-thioxo -1,2-dihydropyridine-3-carbox amide 24 T x’"" ' N-butyl-2-thioxo-1,2-dihydrop yridine- 3 -carboxamide