Solubilization of thiopyridone compounds and compositions comprising same

Abstract

The present invention relates to a composition comprising: (1) at least one thiopyridone compound; and (2) at least one compound selected from vitamin B3 and derivatives thereof. The present invention can provide compositions comprising (1) thiopyridone compound (s), wherein the solubility of the (1) thiopyridone compound (s) increases over time.

Description

Technical Field

[0001] The present invention relates to stabilized compositions comprising thiopyridone compounds and to their use for caring for keratin materials, in particular the skin. Background Art

[0002] At different times in their lives, some people notice the appearance of darker and / or more pigmented spots on their skin, more particularly on their face and hands, which give the skin an uneven appearance. These spots are caused in particular by a high concentration of melanin in the keratinocytes located on the surface of the skin.

[0003] For the treatment of pigmented spots, it is most particularly desirable to use topical depigmenting substances that have good efficacy and are harmless.

[0004] For example, arbutin, niacinamide, and kojic acid are known skin depigmenting agents.

[0005] On the other hand, it has been found that certain thiopyridone compounds, such as those disclosed in WO2012 / 080075 and WO2017 / 102349, exhibit good depigmentation activity even at low concentrations. The thiopyridone compounds can exhibit strong depigmentation or whitening effects by reducing the production of melanin. Summary of the invention

[0006] However, it has been found that thiopyridone compounds may not dissolve completely in the composition, thereby reducing the bioavailability of the thiopyridone compounds. Therefore, a composition is needed, which comprises (one or more) thiopyridone compounds, (one or more) of which have solubility and stability that increase over time.

[0007] The above object can be achieved by a composition comprising:

[0008] (1) at least one compound selected from the group consisting of a compound of the following formula (I), a tautomer of the following formula (I'), a salt thereof, a solvate thereof such as a hydrate thereof, an optical isomer thereof, a racemate thereof, and a mixture thereof:

[0009]

[0010] in

[0011] R1 represents a group selected from the following

[0012] a) hydrogen atoms, and

[0013] b) Saturated straight chain C1-C 10 or branched C3-C 10 An alkyl group, which is optionally substituted by one or more groups, which may be the same or different, selected from

[0014] i)-O-R3, and

[0015] ii) -S-R3,

[0016] and

[0017] R2 represents a group selected from the following

[0018] a) Hydrogen atoms,

[0019] b) Saturated straight chain C1-C 12 or branched C3-C 12 or a cyclic C3-C8 hydrocarbon group, which is optionally substituted by one or more groups which may be the same or different, selected from

[0020] i) -O-R3,

[0021] ii) -S-R3,

[0022] iii) -C(O)-O-R3, and

[0023] iv) C5-C 12 an aryl group, which is optionally substituted with one or more hydroxyl groups and / or one or more C1-C8 alkoxy groups, and

[0024] c) C5-C 12 Aryl groups, which are optionally substituted with one or more hydroxyl groups and / or one or more C1-C8 alkoxy groups

[0025] in

[0026] R3 represents a group selected from the following

[0027] a) hydrogen atoms, and

[0028] b) Saturated straight chain C1-C 10 or branched C3-C 10 Alkyl groups;

[0029] as well as

[0030] (2) At least one compound selected from vitamin B3 and its derivatives.

[0031] Preferably:

[0032] R1 in formula (I) and (I') represents a hydrogen atom;

[0033] or

[0034] In formula (I) and (I'), R1 represents a straight chain (C1-C 10) alkyl group or branched (C3-C 10 )alkyl group, especially a straight-chain (C1-C6)alkyl group or a branched (C3-C6)alkyl group, such as methyl, ethyl, n-pentyl, n-nonyl, isobutyl, more preferably ethyl, and in particular, the alkyl group of R1 is unsubstituted.

[0035] Preferably:

[0036] R2 in formula (I) and (I') represents a hydrogen atom;

[0037] or

[0038] R2 in formula (I) and (I') represents a straight chain (C1-C 10 ) alkyl group or branched (C3-C 10 )alkyl group, especially a straight-chain (C1-C6)alkyl group or a branched (C3-C6)alkyl group, such as methyl, ethyl, n-pentyl, n-nonyl, isobutyl, more preferably a methyl or ethyl group; the alkyl group of R2 is unsubstituted.

[0039] Preferably:

[0040] R2 in formula (I) and (I') represents a straight chain (C1-C 10 ) alkyl group or branched (C3-C 10 )alkyl group, especially a straight-chain (C1-C6)alkyl group or a branched (C3-C6)alkyl group, such as methyl, ethyl, n-pentyl, n-nonyl, isobutyl, more preferably methyl or ethyl; the alkyl group is substituted by one or more groups selected from i), ii), iii) and iv) as defined above, preferably the alkyl group is substituted by one or two groups selected from i), ii) and iii), more preferably substituted by one or two groups selected from i) and iii), more preferably substituted by a group iii), such as carboxyl.

[0041] Preferably:

[0042] R2 in formula (I) and (I') represents a (C3-C8) cycloalkyl group, preferably a (C5-C7) cycloalkyl group such as cyclohexyl;

[0043] or

[0044] R2 in formula (I) and (I') represents C5-C 12 An aryl group, which is optionally substituted by one or more hydroxyl groups and / or one or more C1-C8 alkoxy groups, is preferably a phenyl group, especially an unsubstituted phenyl group.

[0045] Preferably:

[0046] R3 in formula (I) and (I') represents a hydrogen atom;

[0047] or

[0048] R3 in formula (I) and (I') represents a saturated straight chain C1-C 10 or branched C3-C 10 Alkyl group; in particular a straight chain (C1-C6) alkyl group or a branched chain (C3-C6) alkyl group, preferably a (C1-C4) alkyl group such as a methyl group.

[0049] Preferably:

[0050] R1 in formula (I) and (I') represents a group selected from the following

[0051] a) hydrogen atoms, and

[0052] b) a saturated straight-chain C1-C6 or branched C3-C6 alkyl group, which is optionally substituted by one or more groups which may be the same or different and are selected from

[0053] i)-O-R3, and

[0054] ii) -S-R3,

[0055] Preferably optionally substituted with one or more groups i);

[0056] R2 in formula (I) and (I') represents a group selected from the following

[0057] a) hydrogen atoms, and

[0058] b) Saturated straight chain C1-C 10 or branched C3-C 10 or a cyclic C3-C8 (e.g. C5-C6) hydrocarbon group, which is optionally substituted by one or more groups which may be the same or different and are selected from

[0059] i) -O-R3,

[0060] ii) -S-R3,

[0061] iii) -C(O)-O-R3, and

[0062] iv) a phenyl group, which is optionally substituted by one or more hydroxyl groups and / or one or more C1-C4 alkoxy groups, such as methoxy groups,

[0063] Preferably substituted with one or more groups selected from i) and iii), preferably iii), such as carboxyl; and

[0064] R3 in formula (I) and (I') represents a group selected from the following

[0065] a) hydrogen atoms, and

[0066] b) a saturated straight-chain C1-C6 or branched C3-C6 alkyl group,

[0067] Preferably, the compound of formula (I) and tautomer (I'), its salt, its solvate (such as hydrate), its optical isomer, its racemate and mixture thereof have the following meanings:

[0068] R1 in formula (I) and (I') represents a group selected from the following:

[0069] a) hydrogen atoms, and

[0070] b) a saturated linear C1-C4 or branched C3-C4 alkyl group, optionally substituted by one or more groups which may be the same or different, selected from i) -OR3, more preferably unsubstituted;

[0071] R2 in formula (I) and (I') represents a group selected from the following:

[0072] a) hydrogen atoms, and

[0073] b) Saturated straight chain C1-C 10 or branched C3-C 10 or a cyclic C3-C8 (e.g. C5-C6) hydrocarbon group, which is optionally substituted by one or more groups which may be the same or different and are selected from

[0074] i) -O-R3,

[0075] iii) -C(O)-O-R3, and

[0076] iv) C5-C 12 an aryl group, which is optionally substituted with one or more hydroxyl groups and / or one or more C1-C4 alkoxy groups; and

[0077] R3 in formula (I) and (I') represents a group selected from the following:

[0078] a) Hydrogen atom;

[0079] b) a saturated straight-chain C1-C4 or branched C3-C4 alkyl group, for example methyl or ethyl.

[0080] The (1) compound can be selected from the following compounds 1 to 24, their tautomers, their salts, their solvates, such as hydrates, their optical isomers, their racemates and mixtures thereof, in particular compounds 1, 2, 4, 6, 7, 9, 11, 12, 14, 15, 16, 17, 18, 19, 20 or 21, more in particular 1, 9, 16, 18, 19, 20 or 21, preferably 18, 19, 20 or 21, more preferably 20:

[0081]

[0082]

[0083]

[0084]

[0085] The amount of the compound(s) (1) in the composition according to the invention may be 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.

[0086] The at least one compound (2) is preferably vitamin B3.

[0087] The amount of vitamin B3 or a derivative thereof in the composition according to the invention may range from 0.06% to 60% by weight, preferably from 0.3% to 30% by weight, more preferably from 0.6% to 18% by weight, relative to the total weight of the composition.

[0088] The composition according to the invention can be used for whitening keratinous substances, preferably the skin.

[0089] The present invention also relates to a cosmetic method, preferably a whitening method, for keratinous substances, preferably skin, comprising the following steps:

[0090] The composition according to the invention is applied to the keratinous material.

[0091] Another aspect of the present invention is the use of at least one compound b) selected from vitamin B3 and its derivatives in a composition comprising at least one compound (1) selected from the group consisting of compounds of the following formula (I), tautomers of the following formula (I′), salts thereof, solvates thereof, such as hydrates, optical isomers thereof, racemates thereof and mixtures thereof, to stabilize (one or more) compounds of (1):

[0092]

[0093] in

[0094] R1 represents a group selected from the following

[0095] a) hydrogen atoms, and

[0096] b) Saturated straight chain C1-C 10 or branched C3-C 10 An alkyl group, which is optionally substituted by one or more groups, which may be the same or different, selected from

[0097] i)-O-R3, and

[0098] ii) -S-R3,

[0099] as well as

[0100] R2 represents a group selected from the following

[0101] a) Hydrogen atoms,

[0102] b) Saturated straight chain C1-C 12 or branched C3-C 12 or a cyclic C3-C8 hydrocarbon group, which is optionally substituted by one or more groups which may be the same or different, selected from

[0103] i) -O-R3,

[0104] ii) -S-R3,

[0105] iii) -C(O)-O-R3, and

[0106] iv) C5-C 12 an aryl group, which is optionally substituted with one or more hydroxyl groups and / or one or more C1-C8 alkoxy groups, and

[0107] c) C5-C 12 Aryl groups, which are optionally substituted with one or more hydroxyl groups and / or one or more C1-C8 alkoxy groups

[0108] in

[0109] R3 represents a group selected from the following

[0110] a) hydrogen atoms, and

[0111] b) Saturated straight chain C1-C 10 or branched C3-C 10 Alkyl group. DETAILED DESCRIPTION

[0112] After diligent research, the inventors have discovered that it is possible to provide a composition comprising one or more thiopyridone compounds, wherein the solubility of the thiopyridone compound(s) increases over time.

[0113] Therefore, the composition according to the invention comprises:

[0114] (1) at least one compound selected from the group consisting of a compound of the following formula (I), a tautomer of the following formula (I'), a salt thereof, a solvate thereof such as a hydrate, an optical isomer thereof, a racemate thereof, and a mixture thereof (hereinafter, the compound is referred to as a "thiopyridone compound"):

[0115]

[0116] in

[0117] R1 represents a group selected from the following

[0118] a) hydrogen atoms, and

[0119] b) Saturated straight chain C1-C 10 or branched C3-C 10 An alkyl group, which is optionally substituted by one or more groups, which may be the same or different, selected from

[0120] i)-O-R3, and

[0121] ii) -S-R3,

[0122] as well as

[0123] R2 represents a group selected from the following

[0124] a) Hydrogen atoms,

[0125] b) Saturated straight chain C1-C 12 or branched C3-C 12 or a cyclic C3-C8 hydrocarbon group, which is optionally substituted by one or more groups which may be the same or different, selected from

[0126] i) -O-R3,

[0127] ii) -S-R3,

[0128] iii) -C(O)-OR3, and

[0129] iv) C5-C 12 an aryl group, which is optionally substituted with one or more hydroxyl groups and / or one or more C1-C8 alkoxy groups, and

[0130] c) C5-C 12 Aryl groups, which are optionally substituted with one or more hydroxyl groups and / or one or more C1-C8 alkoxy groups

[0131] in

[0132] R3 represents a group selected from the following

[0133] a) hydrogen atoms, and

[0134] b) Saturated straight chain C1-C 10 or branched C3-C 10 Alkyl groups;

[0135] as well as

[0136] (2) At least one compound selected from vitamin B3 and its derivatives.

[0137] The composition according to the present invention can exhibit (1) increased solubility of the thiopyridone compound therein.

[0138] In other words, the composition according to the present invention can increase the solubility of (1) the thiopyridone compound therein. The increased "solubility" means that the composition according to the present invention containing the (1) thiopyridone compound does not exhibit any turbidity but is uniform, transparent and stable.

[0139] Furthermore, the increased solubility of (1) the thiopyridone compound can provide (1) improved or enhanced bioavailability of the thiopyridone compound, which can act as a depigmenting or whitening agent. Thus, the composition according to the present invention can provide an enhanced or improved depigmenting or whitening effect.

[0140] Hereinafter, the composition, use, etc. according to the present invention will be described in a detailed manner.

[0141] [Composition]

[0142] The composition according to the invention comprises:

[0143] (1) at least one thiopyridone compound; and

[0144] (2) At least one compound selected from vitamin B3 and its derivatives.

[0145] The (1) thiopyridone compound, and (2) vitamin B3 and its derivatives, and other features of the composition according to the present invention will be explained below.

[0146] (Thiopyridone compounds)

[0147] The composition according to the present invention comprises (1) at least one thiopyridone compound. Two or more (1) thiopyridone compounds may be used in combination. Thus, a single type of (1) thiopyridone compound or a combination of different types of (1) thiopyridone compounds may be used.

[0148] The (1) thiopyridone compound is selected from the group consisting of a compound of the following formula (I), a tautomer of the following formula (I'), a salt thereof, a solvate thereof, such as a hydrate thereof, an optical isomer thereof, a racemate thereof, and a mixture thereof:

[0149]

[0150] in

[0151] R1 represents a group selected from the following

[0152] a) hydrogen atoms, and

[0153] b) Saturated straight chain C1-C 10 or branched C3-C 10 An alkyl group, which is optionally substituted by one or more groups, which may be the same or different, selected from

[0154] i)-O-R3, and

[0155] ii) -S-R3,

[0156] as well as

[0157] R2 represents a group selected from the following

[0158] a) Hydrogen atoms,

[0159] b) Saturated straight chain C1-C 12 or branched C3-C 12 or a cyclic C3-C8 hydrocarbon group, which is optionally substituted by one or more groups which may be the same or different, selected from

[0160] i) -O-R3,

[0161] ii) -S-R3,

[0162] iii) -C(O)-O-R3, and

[0163] iv) C5-C 12 an aryl group, which is optionally substituted with one or more hydroxyl groups and / or one or more C1-C8 alkoxy groups, and

[0164] c) C5-C 12 Aryl groups, which are optionally substituted with one or more hydroxyl groups and / or one or more C1-C8 alkoxy groups

[0165] in

[0166] R3 represents a group selected from the following

[0167] a) hydrogen atoms, and

[0168] b) Saturated straight chain C1-C 10 or branched C3-C 10 Alkyl group.

[0169] Hereinafter, for the purpose of the present invention and unless otherwise specified:

[0170] - "Saturated straight chain C1-C 12 or branched C3-C 12 "Hydrocarbon group is equivalent to "straight chain (C1-C 12 ) alkyl or branched (C3-C 12 ) alkyl group", which corresponds to a saturated straight-chain C1-C 12 or branched C3-C 12 Hydrocarbyl groups, preferably straight chain C1-C 10 or branched C3-C 10 A hydrocarbon group, more preferably a straight-chain C1-C6 or branched C3-C6 hydrocarbon group; preferably, the straight-chain or branched group may be selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl and tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl; more preferably, a saturated straight-chain or branched alkyl group may 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;

[0171] - a saturated "cyclic C3-C8" hydrocarbon radical is a monocyclic or bicyclic cycloalkyl radical containing 3 to 8 carbon atoms, in particular a C5 to C7 monocyclic cycloalkyl radical, for example a cyclohexyl radical,

[0172] - "Alkoxy group" is an alkyl-oxy group in which the alkyl group is a straight or branched C1-C 16 , preferably a C1-C8 hydrocarbon group;

[0173] - when the alkoxy group is optionally substituted, this means that the alkyl group is optionally substituted as defined above;

[0174] - an "aryl" group means a fused or non-fused monocyclic or bicyclic carbonyl group containing 5 to 12 carbon atoms, preferably 6 to 10 carbon atoms, and wherein at least one ring is aromatic; preferably, the aryl group is phenyl, biphenyl, naphthyl, more preferably a phenyl group;

[0175] - the term "at least one" is equivalent to the term "one or more"; and

[0176] - With respect to a concentration range, the term "inclusive" means that the endpoints of the range are included in the defined range.

[0177] Salts of compounds of formula (I), (I'), (II) or (II') as defined below include conventional non-toxic salts of said compounds, such as those formed from organic or inorganic acids or from organic or inorganic bases.

[0178] As salts of the compounds of formula (I), (I'), (II) or (II'), mention may be made of:

[0179] Salts obtained by addition of a compound of formula (I) or (II) with:

[0180] - inorganic bases, for example sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonium hydroxide, magnesium hydroxide, lithium hydroxide and for example sodium, potassium or calcium carbonate or sodium, potassium or calcium bicarbonate;

[0181] or

[0182] - an organic base, for example a primary, secondary or tertiary alkylamine, for example triethylamine or butylamine. The primary, secondary or tertiary alkylamine may contain one or more nitrogen and / or oxygen atoms and may thus contain, 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.

[0183] Mention may also be made of the salts of amino acids, for example lysine, arginine, guanidine, glutamic acid and aspartic acid. Advantageously, the salts of the compounds of formula (I) or (II) when they contain a carboxyl group may be chosen from alkali metal salts or alkaline earth metal salts, for example sodium, potassium, calcium or magnesium salts and ammonium salts.

[0184] "Organic acid salt or inorganic acid salt" is more specifically selected from the following salts, which are selected from the salts derived from the following: 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 acid: Alk-OS(O)OH, such as methoxysulfinic acid and ethoxysulfinic acid; xi) aryloxysulfinic acid, such as tolyloxysulfinic acid and phenoxysulfinic acid; xii) phosphoric acid H3PO4; xiii) acetic acid CH3C(O)OH; xiv) trifluoromethanesulfonic acid CF3SO3H; and xv) tetrafluoroboric acid HBF4.

[0185] The acceptable solvates of the compounds described in this specification include conventional solvates, such as those formed due to the presence of solvents in the process of preparing the compounds. For example, solvates formed due to the presence of water or straight or branched alcohols (such as ethanol or isopropanol) can be mentioned.

[0186] Optical isomers are specifically enantiomers and diastereomers.

[0187] According to the following scheme, when tautomeric equilibrium exists, compound (I') is a tautomeric form of compound (I):

[0188]

[0189] According to one embodiment of the invention, R1 represents a hydrogen atom.

[0190] According to another embodiment of the present invention, R1 represents a straight chain (C1-C 10 ) alkyl group or branched (C3-C 10 )alkyl group, especially a straight chain (C1-C6)alkyl group or a branched chain (C3-C6)alkyl group, such as methyl, ethyl, n-pentyl, n-nonyl, isobutyl, more preferably ethyl. In particular, the alkyl group of R1 is unsubstituted.

[0191] According to one embodiment of the invention, R2 represents a hydrogen atom.

[0192] According to another embodiment of the present invention, R2 represents a straight chain (C1-C 10 ) alkyl group or branched (C3-C 10 )alkyl group, especially a straight-chain (C1-C6)alkyl group or a branched (C3-C6)alkyl group, such as methyl, ethyl, n-pentyl, n-nonyl, isobutyl, more preferably a methyl or ethyl group; the alkyl group of R2 is unsubstituted.

[0193] According to another embodiment of the present invention, R2 represents a straight chain (C1-C 10 ) alkyl group or branched (C3-C 10 )alkyl group, especially a linear (C1-C6)alkyl group or a branched (C3-C6)alkyl group, such as methyl, ethyl, n-pentyl, n-nonyl, isobutyl, more preferably methyl or ethyl; the alkyl group is substituted by one or more groups selected from i), ii), iii) and iv) as defined above. Preferably, the alkyl group is substituted by one or two groups selected from i), ii) and iii), more preferably by one or two groups selected from i) and iii), more preferably by one group iii), such as carboxyl.

[0194] Another variant of the radical R2 is that the alkyl radical is substituted by a radical iv), in particular by a phenyl radical.

[0195] According to another embodiment of the present invention, R2 represents a (C3-C8)cycloalkyl group, preferably a (C5-C7)cycloalkyl group, such as cyclohexyl.

[0196] According to another embodiment of the present invention, R2 represents C5-C 12 An aryl group, which is optionally substituted by one or more hydroxyl groups and / or one or more C1-C8 alkoxy groups, is preferably a phenyl group, especially an unsubstituted phenyl group.

[0197] According to one embodiment, R3 represents a hydrogen atom.

[0198] According to another embodiment, R3 represents a saturated straight-chain C1-C 10 or branched C3-C 10 Alkyl group; in particular a straight chain (C1-C6) alkyl group or a branched chain (C3-C6) alkyl group, preferably a (C1-C4) alkyl group such as a methyl group.

[0199] Preferably, the compound of formula (I) and its tautomer (I') or its salt, optical isomer, racemate and / or solvate (such as hydrate) thereof, alone or as a mixture

[0200] Has the following meanings:

[0201] R1 represents a group selected from the following

[0202] a) hydrogen atoms, and

[0203] b) a saturated straight-chain C1-C6 or branched C3-C6 alkyl group, which is optionally substituted by one or more groups which may be the same or different and are selected from

[0204] i)-O-R3, and

[0205] ii) -S-R3,

[0206] Preferably optionally substituted with one or more groups i);

[0207] R2 represents a group selected from the following

[0208] a) Hydrogen atom;

[0209] b) Saturated straight chain C1-C 10 or branched C3-C 10 or a cyclic C3-C8 (e.g. C5-C6) hydrocarbon group, which is optionally substituted by one or more groups which may be the same or different, selected from:

[0210] i) -O-R3,

[0211] ii) -S-R3,

[0212] iii) -C(O)-O-R3, and

[0213] iv) a phenyl group, which is optionally substituted by one or more hydroxyl groups and / or one or more C1-C4 alkoxy groups, such as methoxy groups,

[0214] is preferably substituted with one or more groups selected from i) and iii), preferably iii), such as carboxyl; and

[0215] R3 represents a group selected from the following

[0216] a) hydrogen atoms, and

[0217] b) a saturated straight-chain C1-C6 or branched C3-C6 alkyl group.

[0218] Preferably, the compound of formula (I) and the tautomer (I') or a salt thereof, an optical isomer thereof, a racemate thereof and / or a solvate thereof (such as a hydrate), alone or as a mixture

[0219] Has the following meanings:

[0220] R1 represents a group selected from the following

[0221] a) hydrogen atoms, and

[0222] b) a saturated linear C1-C4 or branched C3-C4 alkyl group, optionally substituted by one or more groups which may be the same or different, selected from i) -OR3, more preferably unsubstituted;

[0223] R2 represents a group selected from the following

[0224] a) hydrogen atoms; and

[0225] b) Saturated straight chain C1-C 10 or branched C3-C 10 or a cyclic C3-C8 (e.g. C5-C6) hydrocarbon group, which is optionally substituted by one or more groups which may be the same or different and are selected from

[0226] i) -O-R3,

[0227] iii) -C(O)-O-R3,

[0228] iv) C5-C 12an aryl group, which is optionally substituted with one or more hydroxyl groups and / or one or more C1-C4 alkoxy groups; and

[0229] R3 represents a group selected from the following

[0230] a) hydrogen atoms, and

[0231] b) a saturated straight-chain C1-C4 or branched C3-C4 alkyl group, for example methyl or ethyl.

[0232] Preferably, the compound of formula (I) and its tautomer (I') or its salt, optical isomer, racemate and / or solvate (such as hydrate) thereof, alone or as a mixture

[0233] Has the following meanings:

[0234] R1 is a hydrogen atom; and

[0235] R2 represents a group selected from the following

[0236] a) hydrogen atoms, and

[0237] b) a saturated linear C1-C5 or branched C3-C5 or cyclic C3-C8 (e.g. C5-C6) hydrocarbon group substituted by one or more groups which may be identical or different and selected from v) -C(O)-O-R3, preferably substituted by a group iii) -C(O)-O-R3; R2 is even more preferably a saturated linear C1-C4 or branched C3-C4 hydrocarbon group substituted by a group iii) -C(O)-OR3; and

[0238] R3 represents a group selected from the following

[0239] a) hydrogen atoms, and

[0240] b) Saturated straight-chain C1-C4 or branched C3-C4 alkyl groups such as methyl or ethyl.

[0241] According to another preferred embodiment, the compound of formula (I) and the tautomer (I') are selected from the compounds of formula (II) below and the tautomers thereof, their salts, their solvates and their optical isomers, and their racemates, alone or as a mixture:

[0242]

[0243] In formulae (II) and (II′), R1 and R3 have the same meanings as R1 and R3 in the compounds of formulae (I) and (I′), and X represents an alkylene group -(CH2) n-, wherein n is an integer from 1 to 10 (inclusive), preferably from 1 to 6, more preferably from 1 to 4, for example 1, preferably R3 represents a hydrogen atom.

[0244] Among the compounds of formula (I), preference is given to using the following compounds and their tautomers or salts thereof, their optical isomers, their racemates and / or their solvates (such as hydrates), alone or as a mixture:

[0245]

[0246]

[0247]

[0248]

[0249] Among these compounds, the following compounds are more particularly preferred:

[0250]

[0251]

[0252]

[0253] More preferably, among these compounds, the following compounds are more particularly preferred:

[0254]

[0255] Even more preferably, among these compounds, the following compounds are more particularly preferred:

[0256]

[0257] In the most preferred embodiment, the compounds according to the invention are as follows:

[0258]

[0259] All of the above compounds can be obtained from commercially available reagents by chemical methods known to those skilled in the art.

[0260] The (1) thiopyridone compound can be prepared according to the method described in, for example, EP-A-3390363 or WO2017 / 102349, which are incorporated herein by reference.

[0261] The (1) thiopyridone compound may be an active ingredient or active compound in a cosmetic or dermatological product. The term "active" ingredient or compound as used herein refers to an ingredient or compound having cosmetic or dermatologically active properties, such as antioxidant, whitening, UV filtering effect and antibacterial effect. The (1) thiopyridone compound used in the present invention may be used as a decolorizing agent, bleaching agent or whitening agent, and thus the composition according to the present invention may be used as a whitening product or a cosmetic composition for whitening keratin substances.

[0262] The (1) thiopyridone compounds can be used as agents for depigmenting, bleaching or whitening the skin, body hair, eyelashes or hair and lips and / or nails and preferably the skin, in particular for eliminating pigmentation spots or aging spots, and / or as anti-tanning agents.

[0263] The amount of the (one or more) (1) thiopyridone compounds in the composition according to the present invention may be 0.01 wt% or more, preferably 0.05 wt% or more, more preferably 0.1 wt% or more, relative to the total weight of the composition.

[0264] On the other hand, the amount of the (one or more) (1) thiopyridone compounds in the composition according to the present invention can be 10 wt% or less, preferably 5 wt% or less, more preferably 3 wt% or less, relative to the total weight of the composition.

[0265] The amount of the (one or more) (1) thiopyridone compounds in the composition according to the present invention may be 0.01 to 10 wt %, preferably 0.05 to 5 wt %, more preferably 0.1 to 3 wt %, relative to the total weight of the composition.

[0266] (Vitamin B3)

[0267] Vitamin B3, also known as vitamin PP, is a compound with the following formula:

[0268]

[0269] Wherein R can be -CONH2 (nicotinamide), -COOH (nicotinic acid or nicotinic acid), or CH2OH (nicotinyl alcohol), -CO-NH-CH2-COOH (nicotinuric acid) or -CO-NH-OH (nicotinyl hydroxamic acid). Nicotinamide is preferred.

[0270] Vitamin B3 derivatives that may be mentioned include, for example, nicotinic acid esters, such as tocopheryl nicotinate; amides derived from nicotinamide by substitution of the hydrogen group of -CONH2; products from reactions with carboxylic acids and amino acids; esters of nicotinic acid alcohol with carboxylic acids, such as acetic acid, salicylic acid, glycolic acid or palmitic acid.

[0271] The following derivatives may also be mentioned: 2-chloronicotinamide, 6-methylnicotinamide, 6-aminonicotinamide, N-methylnicotinamide, N,N-dimethylnicotinamide, N-(hydroxymethyl)nicotinamide, quinolinic acid imide, nicotinanilide, N-benzylnicotinamide, N-ethylnicotinamide, nifenazone, nicotinaldehyde, isonicotinic acid, methylisonicotinic acid, thionicotinamide, niacinamide, 2-mercaptonicotinic acid, nicomol and niaprazine, methyl nicotinate and sodium nicotinate.

[0272] Other vitamin B3 derivatives that may also be mentioned include their inorganic salts, for example chlorides, bromides, iodides or carbonates, and their organic salts, for example salts obtained by reaction with carboxylic acids, such as acetates, salicylates, glycolates, lactates, malates, citrates, mandelates, tartrates, etc.

[0273] In a preferred embodiment, the (2) at least one compound selected from vitamin B3 and its derivatives in the composition of the present invention is niacinamide.

[0274] The amount of (2) at least one compound selected from vitamin B3 and its derivatives in the composition according to the present invention may be 0.06 wt % or more, preferably 0.3 wt % or more, more preferably 0.6 wt % or more, relative to the total weight of the composition.

[0275] On the other hand, the amount of (2) at least one compound selected from vitamin B3 and its derivatives in the composition according to the present invention can be 60 weight % or less, preferably 30 weight % or less, more preferably 18 weight % or less, relative to the total weight of the composition.

[0276] The amount of (2) at least one compound selected from vitamin B3 and its derivatives in the composition according to the present invention may be 0.06 to 60% by weight, preferably 0.3 to 30% by weight, and more preferably 0.6 to 18% by weight, relative to the total weight of the composition.

[0277] In the composition according to the present invention, the weight ratio of the amount of (2) at least one compound selected from vitamin B3 and its derivatives to the amount of (one or more) (1) thiopyridone compounds can be 6 or more, preferably 8 or more, and more preferably 10 or more.

[0278] In the composition according to the present invention, the weight ratio of the amount of (2) at least one compound selected from vitamin B3 and its derivatives to the amount of (one or more) (1) thiopyridone compounds can be 20 or less, preferably 15 or less, and more preferably 12 or less.

[0279] In the composition according to the present invention, the weight ratio of the amount of (2) at least one compound selected from vitamin B3 and its derivatives to the amount of (one or more) (1) thiopyridone compounds can be 6 to 20, preferably 8 to 15, and more preferably 10 to 12.

[0280] (pH adjuster)

[0281] The composition according to the present invention may contain (3) at least one pH adjuster (pH adjusting agent). Two or more pH adjusters may be used in combination. Thus, a single type of pH adjuster or a combination of different types of pH adjusters may be used.

[0282] As (3) the pH adjuster, at least one acidifying agent and / or at least one alkalizing agent (alkaline agent) may be used.

[0283] The acidulant may be a monovalent or polyvalent (eg, divalent) acid.

[0284] The acidulant may be, for example, a mineral (inorganic) acid, such as hydrochloric acid, sulfuric acid, phosphoric acid, or an organic acid, such as a carboxylic acid, for example tartaric acid, citric acid and lactic acid, and also a sulfonic acid.

[0285] The alkalizing agent may be a monovalent or polyvalent (eg, divalent) base.

[0286] The alkalizing agent may be mineral (inorganic), or organic, or a mixture.

[0287] The inorganic alkalizing agent may be selected from aqueous ammonia; alkali metal carbonates or bicarbonates, such as sodium carbonate or potassium carbonate and sodium bicarbonate or potassium bicarbonate; alkali metal hydroxides, such as sodium hydroxide and potassium hydroxide; and mixtures thereof.

[0288] The organic alkalizing agent may be chosen from organic amines having a pKb at 25°C of less than 12, preferably less than 10, even more advantageously less than 6. It should be noted that this is the pKb corresponding to the most basic functional group. Furthermore, the organic amine does not contain any alkyl or alkenyl fatty chain containing more than 10 carbon atoms.

[0289] The organic alkalizing agent may be selected from, for example, alkanolamines, oxyethylenated and / or oxypropylenated ethylenediamines, amino acids and amine compounds of the following formula (III):

[0290]

[0291] in

[0292] W represents a C1-C6 divalent alkylene group, which is optionally substituted by one or more hydroxyl groups or C1-C6 alkyl groups, and is optionally interrupted by one or more heteroatoms (such as O and N), and

[0293] R x , R y , R z and R t may be the same or different and represent a hydrogen atom or a C1-C6 alkyl, C1-C6 hydroxyalkyl or C1-C6 aminoalkyl group.

[0294] Examples of amine compounds of formula (III) that may be mentioned include 1,3-diaminopropane, 1,3-diamino-2-propanol, spermine and spermidine.

[0295] The term "alkanolamine" refers to an organic amine comprising a primary, secondary or tertiary amine functional group and one or more linear or branched C1-C8 alkyl groups bearing one or more hydroxyl groups.

[0296] Alkanolamines, such as monoalkanolamines, dialkanolamines or trialkanolamines containing one to three identical or different C1-C4 hydroxyalkyl groups, may be suitable for use in the present invention. Among compounds of this type, mention may be made of 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.

[0297] The amino acids that may be used are of natural or synthetic origin, in their L, D or racemic form and contain at least one acid function, more particularly chosen from carboxylic acid, sulfonic acid, phosphonic acid or phosphoric acid functions. The amino acids may be in neutral or ionic form.

[0298] As the amino acids which can be used in the present invention, there may be mentioned in particular aspartic acid, glutamic acid, alanine, arginine, ornithine, citrulline, asparagine, carnitine, cysteine, glutamine, glycine, histidine, lysine, isoleucine, leucine, methionine, N-phenylalanine, proline, serine, taurine, threonine, tryptophan, tyrosine and valine.

[0299] It may be preferred that the amino acid is a basic amino acid comprising an additional amine function optionally included in the ring or in a ureido function.

[0300] Such basic amino acids may preferably be selected from those corresponding to the following formula (IV):

[0301]

[0302] in

[0303] R represents a group selected from the following:

[0304]

[0305] -(CH2)3-NH2,

[0306] -(CH2)2-NH2,

[0307] -(CH2)2-NH-CO-NH2, and

[0308]

[0309] Compounds corresponding to formula (IV) include histidine, lysine, arginine, ornithine and citrulline.

[0310] The organic alkalizing agent may be selected from heterocyclic organic amines. In addition to histidine, which has already been mentioned among the amino acids, particular mention may be made of pyridine, piperidine, imidazole, triazole, tetrazole and benzimidazole.

[0311] The organic alkalizing agent may also be selected from amino acid dipeptides. As amino acid dipeptides that can be used in the present invention, mention may be made in particular of carnosine, anserine and baleine.

[0312] The organic alkalizing agent can also be chosen from compounds containing a guanidine functional group. As such amines which can be used in the present invention, in addition to arginine already mentioned as an amino acid, mention may be made in particular of creatine, creatinine, 1,1-dimethylguanidine, 1,1-diethylguanidine, guanidinoacetic acid, metformin, agmatine, N-amidinoalanine, 3-guanidinopropionic acid, 4-guanidinobutyric acid and 2-([amino(imino)methyl]amino)ethane-1-sulfonic acid.

[0313] In a preferred embodiment of the present invention, the organic alkalizing agent may be selected from amino acids, preferably basic amino acids, more preferably arginine, lysine, histidine or a mixture thereof. Even more preferably, the organic alkalizing agent may be arginine.

[0314] Mixed compounds that may be mentioned include salts of the aforementioned amines with acids such as carbonic acid or hydrochloric acid. In particular, guanidine carbonate or monoethanolamine hydrochloride may be used.

[0315] The (3) pH adjuster may be present in an amount of 0.01 wt % or more, preferably 0.05 wt % or more, more preferably 0.1 wt % or more, relative to the total weight of the composition.

[0316] The (3) pH adjuster may be present in an amount of 15 wt% or less, preferably 10 wt% or less, more preferably 5 wt% or less, relative to the total weight of the composition.

[0317] The (3) pH adjuster may be present in an amount of 0.01 to 15 wt %, preferably 0.05 to 10 wt %, more preferably 0.1 to 5 wt % or less, relative to the total weight of the composition.

[0318] It is preferred that the composition according to the present invention has a pH of 4.5 or higher, more preferably 5 or higher.

[0319] It is preferred that the composition according to the present invention has a pH of 6.5 or lower, more preferably 6 or lower.

[0320] It is preferred that the composition according to the invention has a pH of 4.5 to 6.5, more preferably 5-6.

[0321] The pH of the composition refers to the pH of the aqueous phase of the composition according to the invention.

[0322] It may be preferred to also use at least one buffer or buffering agent as the (3) pH adjuster, in combination with an acidifying agent and / or an alkalizing agent, to stabilize the pH of the composition according to the present invention.

[0323] As a buffer, any commonly known buffer can be used. For example, a salt of an acid or base, preferably a salt of a weak acid or base, can be used. For example, if citric acid or lactic acid is used as an acidulant, sodium citrate or sodium lactate can be used as a buffer.

[0324] (water)

[0325] The composition according to the present invention may contain (4) water.

[0326] The amount of (4) water in the composition according to the present invention may be 50 wt% or more, preferably 55 wt% or more, more preferably 60 wt% or more, relative to the total weight of the composition.

[0327] On the other hand, the amount of (4) water in the composition according to the present invention may be 99 wt% or less, preferably 95 wt% or less, more preferably 90 wt% or less, relative to the total weight of the composition.

[0328] The amount of (4) water in the composition according to the present invention may be 50 to 99% by weight, preferably 55 to 95% by weight, more preferably 60 to 90% by weight, relative to the total weight of the composition.

[0329] (caffeine)

[0330] In a particular embodiment of the present invention, the composition according to the present invention may further comprise (5) caffeine.

[0331] The (5) caffeine may be present in an amount of 0.01 wt% or more, preferably 0.5 wt% or more, more preferably 1 wt% or more, relative to the total weight of the composition.

[0332] The (5) caffeine may be present in an amount of 15 wt% or less, preferably 10 wt% or less, more preferably 5 wt% or less, relative to the total weight of the composition.

[0333] The (5) caffeine may be present in an amount of 0.01 to 15 wt %, preferably 0.5 to 10 wt %, more preferably 1 to 5 wt % or less relative to the total weight of the composition.

[0334] In a specific embodiment of the present invention, the composition of the present invention comprises (1) a thiopyridone compound as disclosed above, (2) at least one compound selected from vitamin B3 and its derivatives and (3) caffeine.

[0335] (Other optional additives)

[0336] The composition according to the invention may also comprise any other optional additive(s) commonly used in the cosmetic field, selected from, for example, solvents, chelating agents, cosmetic active agents other than ingredient (1), such as oils, preservatives and mixtures thereof.

[0337] It is a routine matter for a person skilled in the art to adjust the nature and amount of the above optional additives that may be present in the composition according to the invention in such a way that the desired cosmetic properties are not affected thereby.

[0338] As solvents, mention may be made of one or more cosmetically acceptable organic solvents, which may be alcohols: in particular monohydric alcohols, such as ethanol, isopropanol, benzyl alcohol and phenylethyl alcohol; diols, such as ethylene glycol, propylene glycol and butylene glycol; other polyols, such as glycerol, sugars and sugar alcohols; and ethers, such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether and ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether and propylene glycol monobutyl ether and butylene glycol monomethyl ether, butylene glycol monoethyl ether and butylene glycol monobutyl ether.

[0339] The organic solvent(s) may be present in a concentration of 0.01 to 30 wt %, preferably 0.1 to 20 wt %, more preferably 1 to 10 wt % relative to the total weight of the composition.

[0340] [preparation]

[0341] The compositions according to the present invention may be prepared by mixing the essential and optional ingredients described above in a conventional manner.

[0342] For example, the composition according to the present invention can be prepared by a method comprising the following steps:

[0343] mix

[0344] (1) at least one thiopyridone compound; and

[0345] (2) At least one compound selected from vitamin B3 and its derivatives.

[0346] Any optional ingredients may be further mixed.

[0347] The mixing may be performed at any temperature, such as room temperature (eg 20-25°C, preferably at 25°C), preferably at 30°C or higher, preferably 40°C or higher, more preferably 50°C or higher.

[0348] The form of the composition according to the present invention is not particularly limited, and may take various forms, such as W / O emulsion, O / W emulsion, gel, solution, etc. It is preferred that the composition according to the present invention is in the form of an emulsion, preferably an O / W emulsion, more preferably an O / W gel emulsion or a gel.

[0349] [Beauty Methods]

[0350] The composition according to the invention can be used as a cosmetic composition or a dermatological composition, preferably a cosmetic composition, more preferably a cosmetic composition for keratinous substances. As keratinous substances, mention may be made of the skin, scalp, hair, mucous membranes (such as lips) and nails.

[0351] The composition according to the invention can be used as a depigmenting, bleaching or whitening product for keratinous substances such as the skin. In particular, the composition according to the invention can be used as a whitening product.

[0352] The composition according to the invention may preferably be intended for application to keratinous substances, such as the skin, the scalp and / or the lips, preferably the skin.

[0353] Thus, the composition according to the invention can be used in a cosmetic method for keratinous materials, preferably the skin. In one embodiment, the invention relates to a cosmetic method for keratinous materials, preferably the skin, preferably a whitening method, comprising the step of applying a composition according to the invention to the keratinous material.

[0354] The composition according to the invention can be used as a topical cosmetic composition in the form of a lotion, milky lotion, cream, gel, paste, serum, foam or spray.

[0355] [use]

[0356] The present invention also relates to the use of (2) at least one compound selected from vitamin B3 and its derivatives in a composition comprising (1) at least one compound selected from the group consisting of a compound of the following formula (I), a tautomer of the following formula (I'), a salt thereof, a solvate thereof, such as a hydrate thereof, an optical isomer thereof, a racemate thereof, and a mixture thereof, to solubilize (one or more) of the compound (1):

[0357]

[0358] in

[0359] R1 represents a group selected from the following:

[0360] a) hydrogen atoms, and

[0361] b) Saturated straight chain C1-C 10 or branched C3-C 10 An alkyl group, which is optionally substituted by one or more groups, which may be the same or different, selected from:

[0362] i)-O-R3, and

[0363] ii) -S-R3,

[0364] and

[0365] R2 represents a group selected from the following:

[0366] a) Hydrogen atoms,

[0367] b) Saturated straight chain C1-C 12 or branched C3-C 12 or a cyclic C3-C8 hydrocarbon group, which is optionally substituted by one or more groups which may be the same or different, selected from:

[0368] i) -O-R3,

[0369] ii) -S-R3,

[0370] iii) -C(O)-O-R3, and

[0371] iv) C5-C 12 an aryl group, which is optionally substituted with one or more hydroxyl groups and / or one or more C1-C8 alkoxy groups, and

[0372] c) C5-C 12 Aryl groups, which are optionally substituted with one or more hydroxyl groups and / or one or more C1-C8 alkoxy groups

[0373] in

[0374] R3 represents a group selected from the following:

[0375] a) hydrogen atoms, and

[0376] b) Saturated straight chain C1-C 10 or branched C3-C 10 Alkyl group.

[0377] The term "solubilize" has the same meaning as increase solubility.

[0378] The use according to the invention can increase the solubility of the (1) thiopyridone compound in a composition comprising the compound. Thus, the resulting composition is not turbid. The increased solubility of the (1) thiopyridone compound in the composition of the invention thus makes the composition stable and transparent.

[0379] The above explanations concerning (1) the thiopyridone compound and (2) at least one compound selected from vitamin B3 and its derivatives in the composition according to the present invention also apply to those used according to the use according to the present invention.

[0380] The composition in the use according to the invention may comprise any optional ingredients as explained above for the composition according to the invention.

[0381] Example

[0382] The present invention will be described in more detail by way of examples. However, these examples should not be construed as limiting the scope of the present invention.

[0383] [Examples 1-3 and Comparative Examples 1-2]

[0384] [preparation]

[0385] Each composition according to Examples 1 to 3 and Comparative Examples 1 to 2 was prepared by mixing the ingredients shown in Table 1. The numerical values ​​of the amounts of the ingredients are all based on "weight %" based on active materials.

[0386] In order to evaluate the solubility of the thiopyridone compound 20 according to the present invention, a screening test was performed using nicotinamide, or nicotinamide and caffeine. In this test, the thiopyridone compound 20 was mixed with nicotinamide using a magnetic stirrer at room temperature in combination with the raw materials disclosed in Examples 1-3 or Comparative Examples 1-2 and observed for the next 90 minutes.

[0387] The appearance of the mixture was analyzed by examining the suspended or decanted particles and comparing them with the pure thiopyridone compound 20.

[0388] Table 1

[0389]

[0390] Comparative Examples 1 and 2 did not present a homogenous appearance (turbid) after the dissolution protocol. With respect to Examples 1-3, the compositions presented a homogenous and transparent appearance.

Claims

1. A composition, preferably a cosmetic composition, comprising (1) at least one compound selected from the group consisting of a compound of the following formula (I), a tautomer of the following formula (I'), a salt thereof, a solvate thereof such as a hydrate thereof, an optical isomer thereof, a racemate thereof, and a mixture thereof: in R1 represents a group selected from the following a) hydrogen atoms, and b) Saturated straight chain C1-C 10 or branched C3-C 10 An alkyl group, which is optionally substituted by one or more groups, which may be the same or different, selected from i)-O-R3, and ii) -S-R3, as well as R2 represents a group selected from the following a) Hydrogen atoms, b) Saturated straight chain C1-C 12 or branched C3-C 12 or a cyclic C3-C8 hydrocarbon group, which is optionally substituted by one or more groups which may be the same or different, selected from i) -O-R3, ii) -S-R3, iii) -C(O)-O-R3, and iv) C5-C 12 an aryl group, which is optionally substituted with one or more hydroxyl groups and / or one or more C1-C8 alkoxy groups, and c) C5-C 12 Aryl groups, which are optionally substituted with one or more hydroxyl groups and / or one or more C1-C8 alkoxy groups in R3 represents a group selected from the following a) hydrogen atoms, and b) Saturated straight chain C1-C 10 or branched C3-C 10 Alkyl groups; as well as (2) At least one compound selected from vitamin B3 and its derivatives.

2. The composition according to claim 1, wherein: R1 in formula (I) and (I') represents a hydrogen atom; or R1 in formula (I) and (I') represents a straight chain (C1-C 10 ) alkyl group or branched (C3-C 10 )alkyl group, in particular a linear (C1-C6)alkyl group or a branched (C3-C6)alkyl group, such as methyl, ethyl, n-pentyl, n-nonyl, isobutyl, more preferably ethyl, in particular, the alkyl group of R1 is unsubstituted.

3. The composition according to claim 1 or 2, wherein: R2 in formula (I) and (I') represents a hydrogen atom; or R2 in formula (I) and (I') represents a straight chain (C1-C 10 ) alkyl group or branched (C3-C 10 )alkyl group, in particular a straight-chain (C1-C6)alkyl group or a branched (C3-C6)alkyl group, such as methyl, ethyl, n-pentyl, n-nonyl, isobutyl, more preferably a methyl or ethyl group; the alkyl group of R2 is unsubstituted.

4. The composition according to claim 1 or 2, wherein: R2 in formula (I) and (I') represents a straight chain (C1-C 10 ) alkyl group or branched (C3-C 10 )alkyl group, in particular a straight-chain (C1-C6)alkyl group or a branched (C3-C6)alkyl group, such as methyl, ethyl, n-pentyl, n-nonyl, isobutyl, more preferably methyl or ethyl; the alkyl group is substituted by one or more groups selected from i), ii), iii) and iv) as defined above, preferably the alkyl group is substituted by one or two groups selected from i), ii) and iii), more preferably substituted by one or two groups selected from i) and iii), more preferably substituted by a group iii), such as a carboxyl group.

5. The composition according to claim 1 or 2, wherein: R2 in formula (I) and (I') represents a (C3-C8) cycloalkyl group, preferably a (C5-C7) cycloalkyl group such as cyclohexyl; or R2 in formula (I) and (I') represents C5-C 12 An aryl group, which is optionally substituted by one or more hydroxyl groups and / or one or more C1-C8 alkoxy groups, is preferably a phenyl group, especially an unsubstituted phenyl group.

6. A composition according to any one of claims 1 to 5, wherein: R3 in formula (I) and (I') represents a hydrogen atom; or R3 in formula (I) and (I') represents a saturated straight chain C1-C 10 or branched C3-C 10 Alkyl group; in particular a straight-chain (C1-C6)alkyl group or a branched (C3-C6)alkyl group, preferably a (C1-C4)alkyl group, such as a methyl group.

7. A composition according to any one of claims 1 to 6, wherein: R1 in formula (I) and (I') represents a group selected from the following a) hydrogen atoms, and b) a saturated straight-chain C1-C6 or branched C3-C6 alkyl group, which is optionally substituted by one or more groups which may be the same or different and are selected from: i)-O-R3, and ii) -S-R3, Preferably optionally substituted with one or more groups i); R2 in formula (I) and (I') represents a group selected from the following: a) hydrogen atoms, and b) Saturated straight chain C1-C 10 or branched C3-C 10 or a cyclic C3-C8, for example C5-C6, hydrocarbon group, which is optionally substituted by one or more groups which may be the same or different, selected from: i) -O-R3, ii) -S-R3, iii) -C(O)-O-R3, and iv) a phenyl group, which is optionally substituted by one or more hydroxyl groups and / or one or more C1-C4 alkoxy groups, such as methoxy groups, Preferably substituted with one or more groups selected from i) and iii), preferably iii), such as carboxyl; and R3 in formula (I) and (I') represents a group selected from the following: a) hydrogen atoms, and b) a saturated straight-chain C1-C6 or branched C3-C6 alkyl group, Preferably, the compounds of formula (I) and tautomers (I'), their salts, their solvates, such as hydrates, their optical isomers, their racemates and mixtures thereof have the following meanings: R1 in formula (I) and (I') represents a group selected from the following: a) hydrogen atoms, and b) a saturated linear C1-C4 or branched C3-C4 alkyl group, optionally substituted by one or more groups which may be the same or different, selected from i) -OR3, more preferably unsubstituted; R2 in formula (I) and (I') represents a group selected from the following: a) hydrogen atoms, and b) Saturated straight chain C1-C 10 or branched C3-C 10 or a cyclic C3-C8, for example C5-C6, hydrocarbon group, which is optionally substituted by one or more groups which may be the same or different, selected from: i) -O-R3, iii) -C(O)-O-R3, and iv) C5-C 12 an aryl group, which is optionally substituted with one or more hydroxyl groups and / or one or more C1-C4 alkoxy groups; and R3 in formula (I) and (I') represents a group selected from the following: a) Hydrogen atom; b) Saturated straight-chain C1-C4 or branched C3-C4 alkyl groups such as methyl or ethyl.

8. A composition according to any one of claims 1 to 7, wherein: The (1) compound is selected from the following compounds 1 to 24, their tautomers, their salts, their solvates, such as hydrates, their optical isomers, their racemates and mixtures thereof, in particular compounds 1, 2, 4, 6, 7, 9, 11, 12, 14, 15, 16, 17, 18, 19, 20 or 21, more in particular 1, 9, 16, 18, 19, 20 or 21, preferably 18, 19, 20 or 21, more preferably 20:

9. The composition according to any one of claims 1 to 8, wherein the amount of (one or more) the (1) compound in the composition is 0.01% to 10% by weight, preferably 0.05% to 5% by weight, more preferably 0.1% to 3% by weight, relative to the total weight of the composition.

10. The composition according to any one of claims 1 to 9, wherein the amount of (2) at least one compound selected from vitamin B3 and its derivatives in the composition is 0.06% to 60% by weight, preferably 0.3% to 30% by weight, and more preferably 0.6% to 18% by weight, relative to the total weight of the composition.

11. The composition according to any one of claims 1 to 10, wherein the (2) at least one compound selected from vitamin B3 and its derivatives is selected from niacinamide, nicotinic acid, nicotinic alcohol, nicotinuric acid, nicotinyl hydroxamic acid, 2-chloronicotinamide, 6-methylnicotinamide, 6-aminonicotinamide, N-methylnicotinamide, N,N-dimethylnicotinamide, N-(hydroxymethyl)nicotinamide, quinolinic acid imide, nicotinanilide, N-benzylnicotinamide, N-ethylnicotinamide, nifenazone, nicotinaldehyde, isonicotinic acid, methylisonicotinic acid, thionicotinamide, niacinamide, 2-mercaptonicotinic acid, nicotinamide and nicotinamide, methyl nicotinate and sodium nicotinate and mixtures thereof, preferably niacinamide.

12. The composition according to any one of claims 1 to 11, further comprising caffeine in an amount of 0.01 to 15 wt%, preferably 0.5 to 10 wt%, more preferably 1 to 5 wt% or less relative to the total weight of the composition.

13. The composition according to any one of claims 1 to 12, wherein the composition is for whitening keratinous substances, preferably the skin.

14. A cosmetic method, preferably a whitening method, for keratinous material, preferably skin, comprising the following steps: The composition according to any one of claims 1 to 13 is applied to a keratinous material.

15. (2) Use of at least one compound selected from vitamin B3 and its derivatives in a composition comprising at least one compound selected from (1) a compound of the following formula (I), a tautomer of the following formula (I'), a salt thereof, a solvate thereof, such as a hydrate thereof, an optical isomer thereof, a racemate thereof, and a mixture thereof, to solubilize (one or more) said (1) compound(s): in R1 represents a group selected from the following a) hydrogen atoms, and b) Saturated straight chain C1-C 10 or branched C3-C 10 An alkyl group, which is optionally substituted by one or more groups, which may be the same or different, selected from i)-O-R3, and ii) -S-R3, as well as R2 represents a group selected from the following a) Hydrogen atoms, b) Saturated straight chain C1-C 12 or branched C3-C 12 or a cyclic C3-C8 hydrocarbon group, which is optionally substituted by one or more groups which may be the same or different, selected from i) -O-R3, ii) -S-R3, iii) -C(O)-O-R3, and iv) C5-C 12 an aryl group, which is optionally substituted with one or more hydroxyl groups and / or one or more C1-C8 alkoxy groups, and c) C5-C 12 Aryl groups, which are optionally substituted with one or more hydroxyl groups and / or one or more C1-C8 alkoxy groups in R3 represents a group selected from the following a) hydrogen atoms, and b) Saturated straight chain C1-C 10 or branched C3-C 10 Alkyl group.

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