Combinations of one or more alkylamidothiazoles and one or more sarcosine alkyl esters and cosmetic formulations containing such combinations

Abstract

The present invention is in the field of cosmetics and in particular relates to combinations of one or more alkylamidothiazoles and one or more sarcosine alkyl esters and cosmetic formulations containing such combinations. It has been found that the sarcosine alkyl esters significantly increase the solubility of alkylamidothiazoles in cosmetic formulations.

Description

Technical Field

[0001] The present invention belongs to the field of cosmetics, and in particular relates to a combination of one or more alkylamidothiazoles and one or more alkyl sarcosinates and a cosmetic preparation containing such a combination. Background Art

[0002] In general, cosmetics not only contribute to a beautiful and attractive appearance, but their effects also make a decisive contribution to improving people's self-esteem and well-being. Therefore, a wide variety of cosmetics are used for daily cleaning and care of human skin. For example, from DE 102011083259 A1, cosmetic preparations for human skin care are known, which contain alkylamidothiazoles.

[0003] Alkylamidothiazoles are used in cosmetic preparations to combat and prevent unwanted skin pigmentation. In this way, the user's complexion can be decisively improved.

[0004] It is also known from DE 102013226711 A1 that alkylamidothiazoles can be used in cosmetic or dermatological preparations for the prevention and treatment of sensitive skin, itching, dry skin and inflammatory conditions of the human skin. Said document discloses various cosmetic O / W emulsions for application to human skin.

[0005] Furthermore, DE 10 2013 204 110 A1 discloses a large number of cosmetic preparations for caring for human skin which contain alkylamidothiazoles.

[0006] Particularly effective lightening of human skin can be achieved by the combined use of alkylamidothiazoles with one or more cyclodextrins.

[0007] However, the fact that a large number of cosmetic preparations containing alkylamidothiazoles are known to the person skilled in the art should not obscure the fact that a large number of problems can arise when formulating cosmetic or dermatological preparations.

[0008] For example, one disadvantage is that alkylamidothiazoles exhibit relatively low solubility in cosmetically acceptable solvents.

[0009] This situation poses considerable difficulties for manufacturers of cosmetic formulations, as it usually requires large amounts of emollients, which significantly increase the development costs and negative sensory perception of the cosmetic product. Summary of the invention

[0010] Therefore, one object of the present invention is to provide a method for enhancing the solubility of alkylamidothiazoles in cosmetics.

[0011] This objective is achieved by the following combination of substances:

[0012] a) one or more alkylamidothiazoles, and

[0013] b) one or more alkyl sarcosinates of the following general formula

[0014]

[0015] R1 and R2 are independently selected from branched, linear or cyclic alkyl groups having 1 to 18 carbon atoms.

[0016] Surprisingly, the alkyl sarcosinates according to the invention significantly increase the solubility of alkylamidothiazoles compared to other cosmetically acceptable oil components. It is likewise possible and may be advantageous to use one or more alkyl sarcosinates according to the invention as the only one or more oil components in a cosmetic composition as well as in combination with other oil components.

[0017] Another embodiment of the invention is a cosmetic preparation containing such a combination.

[0018] Another embodiment of the present invention is the use of one or more sarcosine esters of the following general formula

[0019]

[0020] R1 and R2 are independently selected from branched, linear or cyclic alkyl groups having 1 to 18 carbon atoms, which serve to increase the solubility of the one or more alkylamidothiazoles in the cosmetic formulation.

[0021] Advantageous embodiments of the invention also include cosmetic or dermatological preparations containing:

[0022] a) one or more alkylamidothiazoles, and

[0023] b) one or more alkyl sarcosinates of the following general formula

[0024] ,

[0025] and its use for whitening human skin.

[0026] Preferably, R1 may be selected from branched alkyl groups having up to 10 carbon atoms, more preferably up to 5 carbon atoms.

[0027] Preferably, R2 may be selected from linear alkyl groups having up to 18 carbon atoms, more preferably up to 15 carbon atoms.

[0028] The most preferred embodiment of the present invention comprises

[0029]

[0030] It is considered to be the chemical formula of isopropyl lauroyl sarcosinate.

[0031] Advantageously, the formulations according to the invention include formulations in which the total amount of the one or more alkylamidothiazoles is, for example, 0.00001% to 10% by weight, preferably 0.001% to 5% by weight, in particular 0.005% to 3% by weight, based on the total weight of the formulation, in order to provide a cosmetic formulation.

[0032] Advantageously, the formulations according to the invention include formulations wherein the total amount of the one or more alkyl sarcosinates is from 0.00008% to 80% by weight, preferably from 0.008% to 40% by weight, in particular from 0.04% to 12% by weight, based on the total weight of the formulation, in order to provide a cosmetic formulation.

[0033] In the context of the present invention, advantageous alkylamidothiazoles are those of the general formula:

[0034]

[0035] Wherein R1, R2, X and Y may be different, partially identical or completely identical, and may independently mean:

[0036] R1=-C1-C24-alkyl (straight chain or branched), -C1-C24-alkenyl (straight chain or branched), -C1-C8-cycloalkyl, -C1-C8-cycloalkyl-alkylhydroxyl, -C1-C24-alkylhydroxyl (straight chain or branched), -C1-C24-alkylamine (straight chain or branched), -C1-C24-alkylaryl (straight chain or branched), -C1-C24-alkylaryl-alkyl-hydroxyl (straight chain or branched), -C1-C24-alkylheteroaryl (straight chain or branched), -C1-C24-alkyl-O-C1-C24-alkyl (straight chain or branched), -C1-C24 alkyl-morpholinyl, -C1-C24 alkyl-piperidinyl, -C1-C24 alkyl-piperazinyl, -C1-C24 alkyl-piperazinyl-N-alkyl,

[0037] R2=H, -C1-C24-alkyl (straight chain or branched chain), -C1-C24-alkenyl (straight chain or branched chain), -C1-C8-cycloalkyl, -C1-C24-hydroxyalkyl (straight chain or branched chain), -C1-C24-alkylaryl (straight chain or branched chain), -C1-C24-alkylheteroaryl (straight chain or branched chain),

[0038] X = -H, -C1-C24-alkyl (straight or branched), -C1-C24-alkenyl (straight or branched), -C1-C8-cycloalkyl, -C1-C24-aryl (optionally mono- or poly-substituted by -OH, -F, -Cl, -Br, -I, -OMe, -NH2, -CN), -C1-C24-heteroaryl (optionally mono- or poly-substituted by -OH, -F, -Cl, -Br, -I, -OMe, -NH2, -CN), -CN monosubstituted or polysubstituted), -C1-C24-alkylaryl (straight chain or branched), -C1-C24-alkylheteroaryl (straight chain or branched), -aryl (optionally monosubstituted or polysubstituted by -OH, -F, -Cl, -Br, -I, -OMe, -NH2, -CN), -phenyl, -2,4-dihydroxyphenyl, -2,3-dihydroxyphenyl, -2,4-dimethoxyphenyl, -2,3-dimethoxyphenyl,

[0039] Y=H, -C1-C24-alkyl (straight or branched), -C1-C24-alkenyl (straight or branched), -C1-C8-cycloalkyl, -C1-C24-aryl, -C1-C24-heteroaryl, -C1-C24-alkylaryl (straight or branched), -C1-C24-alkylheteroaryl (straight or branched), -aryl, -phenyl, -2,4-dihydroxyphenyl, -2,3-dihydroxyphenyl, -2,4-dimethoxyphenyl, -2,3-dimethoxyphenyl, -COO-alkyl, -COO-alkenyl, -COO-cycloalkyl, -COO-aryl, -COO-heteroaryl, and

[0040] X, Y may optionally be a fused aromatic compound, wherein X and Y may form with each other an aromatic or aliphatic carbocyclic or heterocyclic ring system having up to n ring atoms, and wherein the number n may take values ​​from 5 to 8, and the corresponding ring system may in turn be substituted by up to n-1 alkyl, hydroxyl, carboxyl, amino, nitrile functional groups, sulfur-containing substituents, ester groups and / or ether groups.

[0041] The thiazole may be in the form of a free base or a salt: for example a fluoride, chloride, bromide, iodide, sulfate, carbonate, ascorbate, acetate or phosphate, in particular in the form of a halogen salt such as chloride and bromide.

[0042] Furthermore, an advantageous embodiment of the invention is a cosmetic or dermatological preparation having an effective amount of one or more of the above-mentioned alkylamidothiazoles.

[0043] Also in accordance with the invention is the use of the above-described alkylamidothiazoles for the treatment and / or prevention of unwanted skin pigmentation.

[0044] Here, the treatment and / or prevention of unwanted skin pigmentation can be found both in the cosmetic field and in the pharmaceutical field.

[0045] In this respect, the medical (or dermatological) treatment is primarily understood as being directed to diseased skin conditions, whereas the cosmetic treatment and / or prevention of unwanted skin pigmentation primarily concerns healthy skin.

[0046] Advantageously, X is selected from substituted phenyl, in which case the substituents (Z) may be selected from -H, -OH, -F, -Cl, -Br, -I, -OMe, -NH2, -CN, acetyl and may be identical or different.

[0047]

[0048] In a particularly advantageous case, X is selected from phenyl substituted by one or more hydroxyl groups, in which case the substituent (Z) may be selected from -H, -OH, -F, -Cl, -Br, -I, -OMe, -NH2, -CN, acetyl, and preferably the following general structure, wherein Y, R1 and R2 may have the properties defined above.

[0049]

[0050] Particularly advantageous compounds are those wherein

[0051] X =

[0052] Y=H

[0053] R1=-C1-C24-alkyl (straight chain or branched), -C1-C24-alkenyl (straight chain or branched), -C1-C8-cycloalkyl, -C1-C8-cycloalkyl-alkylhydroxyl, -C1-C24 alkylhydroxyl (straight chain or branched), -C1-C24 alkylamine (straight chain or branched), -C1-C24-alkylaryl (straight chain or branched), -C1-C24-alkylaryl-alkyl-hydroxyl (straight chain or branched), -C1-C24-alkylheteroaryl (straight chain or branched), -C1-C24-alkyl-O-C1-C24-alkyl (straight chain or branched), -C1-C24-alkyl-morpholinyl, -C1-C24 alkyl-piperidinyl, -C1-C24 alkyl-piperazinyl, -C1-C24 alkyl-piperazinyl-N-alkyl,

[0054] R2=H, -C1-C24-alkyl (straight or branched chain),

[0055] Z = -H, -OH, -F, -Cl, -Br, -I, -OMe, -NH2, -CN, acetyl.

[0056] Particularly preferred are the following compounds:

[0057] X =

[0058] Y=H

[0059] R1=-C1-C24-alkyl (straight chain or branched), -C1-C24-alkenyl (straight chain or branched), -C1-C8-cycloalkyl, -C1-C8-cycloalkyl-alkylhydroxyl, -C1-C24-alkylhydroxyl (straight chain or branched), -C1-C24-alkylamine (straight chain or branched), -C1-C24-alkylaryl (straight chain or branched), -C1-C24-alkyl-aryl-alkyl-hydroxyl (straight chain or branched), -C1-C24-alkylheteroaryl (straight chain or branched), -C1-C24-alkyl-O-C1-C24-alkyl (straight chain or branched), -C1-C24 alkyl-morpholinyl, -C1-C24 alkyl-piperidinyl, -C1-C24 alkyl-piperazinyl, -C1-C24 alkyl-piperazinyl-N-alkyl,

[0060] R2=H.

[0061] The following compounds are the most preferred compounds within the scope of the present invention:

[0062]

[0063] N-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)pivalamide

[0064]

[0065] N-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)isobutyramide

[0066]

[0067] N-(4-(2,4-Dihydroxyphenyl)thiazol-2-yl)butanamide

[0068]

[0069] N-(4-(2,4-Dihydroxyphenyl)thiazol-2-yl)heptylamide

[0070]

[0071] N-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-6-hydroxyhexanamide

[0072]

[0073] N-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-3-hydroxypropanamide

[0074]

[0075] N-(4-(2,4-Dihydroxyphenyl)thiazol-2-yl)-2-methoxyacetamide

[0076]

[0077] 3-Amino-N-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)propanamide

[0078]

[0079] N-(4-(2,4-Dihydroxyphenyl)thiazol-2-yl)acetamide

[0080]

[0081] N-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-4-(hydroxymethyl)cyclohexanecarboxamide

[0082]

[0083] N-(4-(2,4-Dihydroxyphenyl)thiazol-2-yl)cyclohexanecarboxamide

[0084]

[0085] N-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-2-(4-(hydroxymethyl)phenyl)acetamide.

[0086] Cosmetic or dermatological preparations containing alkylamidothiazoles and their use for the treatment and / or prevention of unwanted skin pigmentation are likewise advantageous embodiments of the invention.

[0087] It is particularly advantageous if such preparations contain from 0.00001 to 10% by weight, in particular from 0.001 to 5% by weight and very particularly from 0.005 to 3% by weight, based on the total weight of the preparation, of one or more alkylamidothiazoles according to the invention (e.g. N-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)isobutyramide, i.e. isobutyramidothiazolylresorcinol).

[0088] It is particularly advantageous if such preparations comprise 0.00008 to 80% by weight, in particular 0.008 to 40% by weight, very particularly 0.04 to 12% by weight, based on the total weight of the preparation, of one or more alkyl sarcosinates (eg isopropyl lauroyl sarcosinate).

[0089] The cosmetic and dermatological preparations according to the invention can take various forms. Thus, they can be, for example, solutions, anhydrous preparations, emulsions or microemulsions of the water-in-oil (W / O) type or of the oil-in-water (O / W) type, multiple emulsions, for example of the water-in-oil-in-water (W / O / W) type, gels, solid sticks, balms or aerosols. According to the invention, it is also advantageous to apply the substances used according to the invention and / or their derivatives in encapsulated form, for example in a collagen matrix and other conventional encapsulation materials, for example as cellulose encapsulation, gelatin or liposome encapsulation.

[0090] In the context of the present invention, it is also possible and advantageous to add the substances used according to the invention and / or their derivatives to aqueous systems or surfactant preparations for cleansing the skin and hair.

[0091] The cosmetic and dermatological preparations according to the invention may contain the cosmetic auxiliaries customary for such preparations, for example preservatives, bactericides, fragrances, substances for preventing foaming, dyes, pigments with a coloring action, thickeners, surface-active substances, emulsifiers, softening, moisturizing and / or humectant substances, fats, oils, waxes or other customary ingredients of cosmetic or dermatological preparations, for example alcohols, polyols, polymers, foam stabilizers, electrolytes, organic solvents or silicone derivatives.

[0092] The lipid phase can advantageously be chosen from the following substances: mineral oils, mineral wax oils such as triglycerides of capric or caprylic acid, and natural oils such as castor oil; fats, waxes and other natural and synthetic fatty bodies, preferably esters of fatty acids with low-carbon alcohols, such as esters with isopropanol, propylene glycol or glycerol, or esters of fatty alcohols with low-carbon alkanoic acids or fatty acids; alkyl benzoates; silicone oils such as dimethylpolysiloxane, diethylpolysiloxane, diphenylpolysiloxane and mixtures thereof.

[0093] In the context of the present invention, the oil phase of the emulsion, oleogel or aqueous or fatty dispersion is advantageously chosen from esters of saturated and / or unsaturated, branched and / or unbranched alkanoic acids with a chain length of 3 to 30 C atoms and saturated and / or unsaturated, branched and / or unbranched alcohols with a chain length of 3 to 30 C atoms, from esters of aromatic carboxylic acids and saturated and / or unsaturated, branched and / or unbranched alcohols with a chain length of 3 to 30 C atoms. Thus, such ester oils may advantageously be chosen from isopropyl myristate, isopropyl palmitate, isopropyl stearate, isopropyl oleate, n-butyl stearate, n-hexyl laurate, n-decyl oleate, isooctyl stearate, isononyl stearate, isononyl isononanoate, 2-ethylhexyl palmitate, 2-ethylhexyl laurate, 2-hexyldecyl stearate, 2-octyldodecyl palmitate, oleyl oleate, oleyl erucate, erucyl oleate, erucyl erucate, and synthetic, semisynthetic and natural mixtures of such esters, for example jojoba oil.

[0094] The aqueous phase of the preparation according to the invention optionally advantageously comprises a humectant, for example propylene glycol, panthenol or hyaluronic acid, and in particular one or more thickeners, which can advantageously be chosen from silicon dioxide, aluminum silicate, hydroxypropylmethylcellulose, particularly advantageously polyacrylates such as carbomer grade 980, in each case alone or in combination.

[0095] In particular, mixtures of the abovementioned solvents are used. In the case of alcoholic solvents, water may be a further component.

[0096] Emulsions according to the invention are advantageous and comprise, for example, certain fats, oils, waxes and other fatty bodies, as well as water and an emulsifier, as is customary for preparations of this type.

[0097] The gels according to the invention generally comprise low-carbon alcohols such as ethanol, propylene glycol and water or the abovementioned oils in the presence of a thickener, preferably silicon dioxide or aluminum silicate in the case of oily alcoholic gels and preferably polyacrylates in the case of aqueous alcoholic gels or alcoholic gels.

[0098] Suitable propellants for the preparations according to the invention which can be sprayed from aerosol containers are the commonly known volatile liquefied propellants, such as hydrocarbons (propane, butane, isobutane), which can be used alone or mixed with one another. Compressed air can also be advantageously used.

[0099] Advantageously, the preparations according to the invention may also advantageously contain substances which absorb UV radiation in the UVB region, the total amount of said filter substances being, for example, 0.1 to 30% by weight, preferably 0.5 to 10% by weight, in particular 1.0 to 6.0% by weight, based on the total weight of the preparation, in order to provide cosmetic preparations which protect the hair and / or skin from the entire range of ultraviolet radiation. They can also be used as sunscreens for the hair or the skin.

[0100] Furthermore, the preparations according to the invention can advantageously additionally contain substances which mask the unpleasant inherent odor of the remaining raw materials used, the total amount of said fragrance ingredients being, for example, 0.001 to 30% by weight, preferably 0.05 to 10% by weight, in particular 0.1 to 5.0% by weight, based on the total weight of the preparation, in order to provide cosmetic preparations. DETAILED DESCRIPTION

[0101] Example

[0102] The following examples are intended to illustrate the present invention without limiting the present invention. Unless otherwise stated, all amounts, parts and percentages stated are by weight and total amount or total weight of the formulation.

[0103] Preparation Example

[0104]

[0105] Effect Examples

[0106] Isobutylamidothiazolylresorcinol + Isopropyl lauroylsarcosinate (solubility 12.5%)

[0107] Isobutylamidothiazolylresorcinol + diisopropyl adipate (solubility 5%)

[0108] Isobutylamidothiazolylresorcinol + PPG-3 octyl ether (solubility 5%)

[0109] Isobutylamidothiazolylresorcinol + dibutyl adipate (solubility 4.4%)

[0110] Isobutylamidothiazolylresorcinol + lauryl lactate (solubility 2.5%)

[0111] Isobutyramidothiazolylresorcinol + diisopropyl sebacate (solubility 2.5%).

Claims

1. A combination of the following substances: a) one or more alkylamidothiazoles, and b) one or more alkyl sarcosinates of the following general formula R1 and R2 are independently selected from branched, linear or cyclic alkyl groups having 1 to 18 carbon atoms.

2. The combination according to claim 1, characterized in that R1 is selected from branched alkyl groups having up to 10 carbon atoms, preferably up to 5 carbon atoms, and R2 is selected from linear alkyl groups having up to 18 carbon atoms, preferably up to 15 carbon atoms.

3. A cosmetic preparation comprising the combination according to claim 1 or 2.

4. Use of one or more alkyl sarcosinates of the following general formula, R1 and R2 are independently selected from branched, linear or cyclic alkyl groups having 1 to 18 carbon atoms, They are used to increase the solubility of one or more alkylamidothiazoles in cosmetic preparations.

5. The use according to claim 4, characterized in that R1 is selected from branched alkyl groups having up to 10 carbon atoms, preferably up to 5 carbon atoms, and R2 is selected from linear alkyl groups having up to 18 carbon atoms, preferably up to 15 carbon atoms.

6. The cosmetic preparation according to claim 2 or 3 or the use according to claim 4 or 5, characterized in that The total amount of the one or more alkylamidothiazoles is 0.00001% to 10% by weight, preferably 0.001% to 5% by weight, especially 0.005% to 3% by weight, based on the total weight of the formulation.

7. The cosmetic preparation according to claim 2 or 3 or the use according to claim 4 or 5, characterized in that Based on the total weight of the preparation, the total amount of the one or more sarcosinates is 0.00008 wt % to 80 wt %, preferably 0.008 wt % to 40 wt %, in particular 0.04 wt % to 12 wt %.

8. The combination, cosmetic preparation or use according to any one of the preceding claims, characterized in that The sarcosine alkyl ester is characterized by the following structure 。 9. The combination, cosmetic preparation or use according to any one of the preceding claims, characterized in that Alkylamidothiazoles are substances having the following general formula: in R1=-C1-C24-alkyl (straight chain or branched), -C1-C24-alkenyl (straight chain or branched), -C1-C8-cycloalkyl, -C1-C8-cycloalkyl-alkylhydroxyl, -C1-C24-alkylhydroxyl (straight chain or branched), -C1-C24-alkylamine (straight chain or branched), -C1-C24-alkylaryl (straight chain or branched), -C1-C24-alkylaryl-alkyl-hydroxyl (straight chain or branched), -C1-C24-alkylheteroaryl (straight chain or branched), -C1-C24-alkyl-O-C1-C24-alkyl (straight chain or branched), -C1-C24 alkyl-morpholinyl, -C1-C24 alkyl-piperidinyl, -C1-C24 alkyl-piperazinyl, -C1-C24 alkyl-piperazinyl-N-alkyl, R2=H, -C1-C24-alkyl (straight chain or branched chain), -C1-C24-alkenyl (straight chain or branched chain), -C1-C8-cycloalkyl, -C1-C24-hydroxyalkyl (straight chain or branched chain), -C1-C24-alkylaryl (straight chain or branched chain), -C1-C24-alkylheteroaryl (straight chain or branched chain), X = -H, -C1-C24-alkyl (straight or branched), -C1-C24-alkenyl (straight or branched), -C1-C8-cycloalkyl, -C1-C24-aryl (optionally mono- or poly-substituted by -OH, -F, -Cl, -Br, -I, -OMe, -NH2, -CN), -C1-C24-heteroaryl (optionally mono- or poly-substituted by -OH, -F, -Cl, -Br, -I, -OMe, -NH2, -CN), -CN monosubstituted or polysubstituted), -C1-C24-alkylaryl (straight chain or branched), -C1-C24-alkylheteroaryl (straight chain or branched), -aryl (optionally monosubstituted or polysubstituted by -OH, -F, -Cl, -Br, -I, -OMe, -NH2, -CN), -phenyl, -2,4-dihydroxyphenyl, -2,3-dihydroxyphenyl, -2,4-dimethoxyphenyl, -2,3-dimethoxyphenyl, Y=H, -C1-C24-alkyl (straight or branched), -C1-C24-alkenyl (straight or branched), -C1-C8-cycloalkyl, -C1-C24-aryl, -C1-C24-heteroaryl, -C1-C24-alkylaryl (straight or branched), -C1-C24-alkylheteroaryl (straight or branched), -aryl, -phenyl, -2,4-dihydroxyphenyl, -2,3-dihydroxyphenyl, -2,4-dimethoxyphenyl, -2,3-dimethoxyphenyl, -COO-alkyl, -COO-alkenyl, -COO-cycloalkyl, -COO-aryl, -COO-heteroaryl, and X, Y may optionally be a fused aromatic compound, wherein X and Y may form with each other an aromatic or aliphatic carbocyclic or heterocyclic ring system having up to n ring atoms, and wherein the number n may take values ​​from 5 to 8, and the corresponding ring system may in turn be substituted by up to n-1 alkyl, hydroxyl, carboxyl, amino, nitrile functional groups, sulfur-containing substituents, ester groups and / or ether groups.

10. The combination, cosmetic preparation or use according to claim 9, characterized in that X is selected from substituted phenyl, wherein Z is selected from -H, -OH, -F, -Cl, -Br, -I, -OMe, -NH2, -CN, acetyl, and may be the same or different, and R1, R2 and Y are as defined in claim 9, 。 11. The combination, cosmetic preparation or use according to claim 9, characterized in that X is selected from substituted phenyl, wherein R2 is selected from H or -C1-C24-alkyl (linear or branched), and R1, Y and Z are as defined in claim 10, , preferably Y is H, R2 is H, and Z is OH.

12. The combination, cosmetic preparation or use according to any one of the preceding claims, characterized in that The alkylamidothiazole is selected from the following substances: N-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)pivalamide N-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)isobutyramide N-(4-(2,4-Dihydroxyphenyl)thiazol-2-yl)butanamide N-(4-(2,4-Dihydroxyphenyl)thiazol-2-yl)heptylamide N-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-6-hydroxyhexanamide N-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-3-hydroxypropanamide N-(4-(2,4-Dihydroxyphenyl)thiazol-2-yl)-2-methoxyacetamide 3-Amino-N-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)propanamide N-(4-(2,4-Dihydroxyphenyl)thiazol-2-yl)acetamide N-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-4-(hydroxymethyl)cyclohexanecarboxamide N-(4-(2,4-Dihydroxyphenyl)thiazol-2-yl)cyclohexanecarboxamide N-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-2-(4-(hydroxymethyl)phenyl)acetamide.

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