Agents for the repigmentation of keratin fibers, especially human hair

Description

[0001] The present invention relates to a cosmetic formulation containing a dye precursor selected from the group consisting of indole derivatives and indolin derivatives, a xanthine derivative, and a direct dye. The invention further relates to the use of the cosmetic formulation for the repigmentation of keratin fibers, in particular human hair.

[0002] A person's hair color depends on the amount of melanins, eumelanin and pheomelanin, contained in the hair's cortex and produced by melanocytes in the hair follicles. As part of the normal aging process, but also due to certain illnesses, stress, vitamin and mineral deficiencies, or excessive alcohol or nicotine consumption, melanin production can decrease, resulting in hypopigmentation. Such hair appears white or colorless to the observer. The visual impression of gray hair results from the mixture of pigmented and unpigmented hairs.

[0003] The average life cycle of a hair is three to seven years, after which the hair falls out and a new hair grows in its place. Gradually, the proportion of white or unpigmented hairs increases, and the hair turns gray.

[0004] Changing hair color, and in particular the pigmentation or repigmentation of gray hair, represents an important area of ​​modern cosmetics. Good colorfastness, effective gray coverage, and long-lasting results are especially desirable.

[0005] For permanent, intense colorations with good fastness properties and good gray coverage, oxidation dyes are conventionally used. Such dyes typically contain oxidation dye precursors, so-called developer components and coupler components, which, under the influence of oxidizing agents, such as hydrogen peroxide, or atmospheric oxygen, react with each other or with one or more coupler components to form the actual dyes.

[0006] However, the use of oxidative dyes is still associated with impairment or damage to the hair and especially its surface structure.

[0007] Alternatively, precursors of the natural hair pigment melanin can be applied to the hair, which, through oxidative processes within the hair, form practically nature-identical pigments. The coloring process can be carried out using atmospheric oxygen as the sole oxidizing agent, thus eliminating the need for any other oxidizing agents. Such a process, using 5,6-dihydroxyindoline as a pigment precursor, is described, for example, in EP 0 530 229 B1.

[0008] In contrast, temporary hair coloring uses direct dyes, also known as direct dyes. These are dye molecules that adhere directly to the hair shaft and do not require an oxidative process to develop the color. Compared to oxidative hair coloring, colorations achieved with direct dyes are less long-lasting and wash out more quickly. Colorations with direct dyes typically remain on the hair for between 5 and 20 washes.

[0009] WO 99 / 66890 describes a dye for dyeing keratin fibers containing a dye precursor, which may be an indoline or indole derivative, e.g., a derivative of 5,6-dihydroxyindoline or 5,6-dihydroxyindole, as well as an amino acid or an oligopeptide. The color can be formed by air oxidation.

[0010] DE 10 2018 127 182 A1 relates to a two-component system for artificial hair coloring, comprising separately an anhydrous carrier medium consisting of an alkane, a fatty alcohol, and an alcohol, and an aqueous phase containing hydrogen peroxide. An organosilicon compound from the silane group may be included for hair protection and conditioning.

[0011] DE 10 2007 038 484 A1 describes a hair treatment product for protection against external influences, wherein the hair treatment product contains bacterial ferment(s) from Thermus thermophilus contains.

[0012] WO 2005 / 007615 A1 concerns 2-(amino or substituted amino)-5-(substituted oxymethyl)-phenol compounds and compositions for the oxidative dyeing of keratin fibers.

[0013] DE102007040313 concerns hair treatment products for strengthening hair, containing a combination of a biotin compound, a taurine compound, a purine compound such as caffeine, and a glycoprotein. The preparation may also contain a color-changing component.

[0014] However, with the formulations known in the prior art, sufficiently satisfactory results in terms of quality, intensity and duration of the coloring performance cannot be achieved while simultaneously minimizing impairment or damage to the hair structure.

[0015] The precursors of the natural hair pigment melanin form the resulting color bodies with a significant time delay, and the color tones are difficult to control. Furthermore, the intermediate shades often appear unnaturally violet. Another disadvantage is the unpigmented roots that become visible as the hair grows out.

[0016] In summary, there is still room for improvement, particularly regarding colorfastness, grey coverage, and the duration of dyeing performance.

[0017] Based on this, the object of the present invention was to provide a cosmetic formulation suitable for the pigmentation or repigmentation of keratin fibers, particularly human hair, and which offers, in particular, improved colorfastness properties of the pigmented or repigmented keratin fibers as well as improved gray coverage. Furthermore, this cosmetic formulation should exhibit improved properties with regard to the quality, intensity, and duration of the coloring effect compared to formulations known from the prior art.

[0018] This problem was surprisingly solved by the formulation according to claim 1 and its use according to claim 5++. Preferred embodiments are described in the dependent claims.

[0019] According to the invention, the problem is solved by providing a cosmetic formulation which contains a dye precursor selected from the group consisting of the indole derivatives and indolin derivatives defined in claim 1, the xanthine derivative caffeine and at least one direct dye.

[0020] Surprisingly, it was found that the contrast to the regrowing hair (hairline) is significantly lower, as the natural pigment production in the hair root is stimulated, while the already grown-out hair is darkened.

[0021] Overall, the hair gradually becomes darker, with the color effect building up subtly, gray hairs being clearly covered, and the overall impression of the hair color appearing significantly darker.

[0022] Thus, the cosmetic formulation according to the invention achieves good grey coverage as well as excellent fastness properties with long-lasting coloring performance and reduced re-greying of the hair roots.

[0023] The xanthine derivative contained in the formulation according to the invention, together with the dye precursor, stimulates the keratinocytes in the hair roots, thereby increasing their production of natural pigment. Furthermore, the xanthine derivative promotes the longer lifespan of the hair on the scalp. This delays the loss of pigmented hair and contributes to the natural repigmentation of hair that is already low in pigment or pigmentless. Within the scope of the present invention, the terms pigmentation and repigmentation are used interchangeably.

[0024] The dye precursor contained in the formulation according to the invention, which is an indole derivative or indolin derivative, is defined in claim 1.

[0025] In a preferred embodiment of the invention, the dye precursor is an indole derivative.

[0026] Preferably according to the invention, the dye precursor is a derivative of the 5,6-dihydroxyindole of formula (I), each independently of each other, R 1< means hydrogen, a C 1-C 4 alkyl group or a C 1-C 4 hydroxyalkyl group, R 2< means hydrogen or a -COOH group, where the -COOH group may also be present as a salt with a physiologically acceptable cation, R 3< means hydrogen or a C 1-C 4 alkyl group, R 4< means hydrogen, a C 1-C 4 alkyl group, an amino group or a group -CO-R 6<, in which R 6< means a C 1-C 4 alkyl group, and R 5< means one of the groups mentioned under R 4<, or a physiologically acceptable salt of these compounds with an organic or inorganic acid.

[0027] Preferred representatives according to the invention are 5,6-dihydroxyindole, N-methyl-5,6-dihydroxyindole, N-ethyl-5,6-dihydroxyindole, N-propyl-5,6-dihydroxyindole, N-butyl-5,6-dihydroxyindole.

[0028] In a particularly preferred embodiment, the compound of formula (I) is selected from 5,6-dihydroxyindole, N-methyl-5,6-dihydroxyindole and their physiologically acceptable salts.

[0029] The dye precursor used in the formulation according to the invention is particularly preferably 5,6-dihydroxyindole.

[0030] In another preferred embodiment of the invention, the dye precursor is an indoline derivative.

[0031] According to the invention, the dye precursor is preferably a derivative of 5,6-dihydroxyindoline of formula (II), each independently of each other, R 1< means hydrogen, a C 1-C 4 alkyl group or a C 1-C 4 hydroxyalkyl group, R 2< means hydrogen or a -COOH group, where the -COOH group may also be present as a salt with a physiologically acceptable cation, R 3< means hydrogen or a C 1-C 4 alkyl group, R 4< means hydrogen, a C 1-C 4 alkyl group, an amino group or a group -CO-R 6<, in which R 6< means a C 1-C 4 alkyl group, and R 5< means one of the groups mentioned under R 4<, or a physiologically acceptable salt of these compounds with an organic or inorganic acid.

[0032] Preferred representatives according to the invention are 5,6-dihydroxyindoline, N-methyl-5,6-dihydroxyindoline, N-ethyl-5,6-dihydroxyindole.

[0033] In a particularly preferred embodiment, the compound of formula (II) is selected from 5,6-dihydroxyindoline, N-methyl-5,6-dihydroxyindoline and their physiologically acceptable salts.

[0034] The dye precursor used in the formulation according to the invention is particularly preferably 5,6-dihydroxyindoline.

[0035] In a further particularly preferred embodiment, the dye precursor used in the formulation according to the invention is dihydroxyindole hydrobromide (2,3-dihydro-1H-indole-5,6-diol hydrobromide).

[0036] The indole and indoline derivatives contained in the compositions according to the invention can be used both as free bases and in the form of their physiologically compatible salts with inorganic or organic acids, e.g. the hydrochlorides, sulfates and hydrobromides.

[0037] The indole or indolin derivative is typically present in the formulation according to the invention in an amount of 0.001-5 wt.%, preferably 0.005-2 wt.%, preferably 0.01-2 wt.%, preferably 0.01-1.5 wt.%, preferably in an amount of about 0.05 wt.%, 0.1 wt.%, 0.2 wt.%, 0.3 wt.%, 0.4 wt.%, 0.5 wt.%, 0.6 wt.%, 0.7 wt.%, 0.8 wt.%, 0.9 wt.%, 1.0 wt.%, 1.5 wt.%, each based on the total weight of the formulation.

[0038] In a particularly preferred embodiment, the dye precursor is an indole derivative, preferably 5,6-dihydroxyindole, wherein this is contained in the formulation according to the invention in an amount of 0.01-2 wt.%, preferably 0.05-0.6 wt.%, preferably in an amount of 0.08-0.5 wt.%, preferably in an amount of about 0.1-0.5 wt.%, in each case based on the total weight of the formulation.

[0039] In a further particularly preferred embodiment, the dye precursor is an indoline derivative, preferably dihydroxyindoline hydrobromide (2,3-dihydro-1H-indole-5,6-diol hydrobromide), wherein this is contained in the formulation according to the invention in an amount of 0.01-4.0 wt.%, preferably 0.05-2.0 wt.%, preferably in an amount of 0.08-1.0 wt.%, preferably in an amount of about 0.1-0.5 wt.%, in each case based on the total weight of the formulation.

[0040] The formulation according to the invention can also contain more than one indole or indolin derivative or mixtures of indole and indolin derivatives.

[0041] The formation of the pigment from the dye precursor, i.e. the indole or indolin derivative, occurs through reaction with atmospheric oxygen; no additional oxidizing agent is required.

[0042] The xanthine derivative contained in the cosmetic formulation, together with the dye precursor, stimulates the keratinocytes in the hair roots to produce more natural pigment. Furthermore, the xanthine derivative promotes longer hair growth, which delays the loss of pigmented hair and contributes to the natural repigmentation of hair that is already lightly pigmented or pigment-free.

[0043] The xanthine derivative according to the invention is caffeine.

[0044] The IUPAC name for caffeine is 1,3,7-trimethyl-3,7-dihydro-1H-purine-2,6-dione. Alternatively, caffeine is also known as 1,3,7-trimethylxanthine. Caffeine is represented by the following chemical formula (III).

[0045] Caffeine is a methylxanthine alkaloid belonging to the class of methylxanthines. It is a bitter crystalline substance, can be considered a purine derivative, and is chemically related to the adenine and guanine bases of deoxyribonucleic acids and ribonucleic acid.

[0046] The xanthine derivative is typically present in the formulation according to the invention in an amount of 0.0001-10 wt.%, preferably 0.01-5 wt.%, preferably 0.05-2 wt.%, preferably 0.1-1.5 wt.%, preferably in an amount of about 0.0001 wt.%, 0.05 wt.%, 0.1 wt.%, 0.2 wt.%, 0.3 wt.%, 0.5 wt.%, 0.7 wt.%, 1.0 wt.%, 1.3 wt.%, 1.4 wt.%, 1.5 wt.%, each based on the total weight of the formulation.

[0047] The formulations according to the invention contain at least one direct dye.

[0048] Surprisingly, it was found that the color effect of a formulation containing not only the indole- or indolin-type dye precursor and the xanthine derivative, but also a direct dye, is more intense than would have been expected based on the color effects of the individual components: the indole- or indolin-type dye precursor and the direct dye. The darkening effects (repigmentation) are synergistically enhanced by the combination with direct dyes, increasing both the speed of color onset and the color depth.

[0049] In the presence of a combination of an indole- or indolin-type dye precursor and a direct dye, a synergistic effect occurs. Thus, with the cosmetic formulation according to the invention, containing an indole- or indolin-type dye precursor, a xanthine derivative, and a direct dye, a particularly intense color effect is advantageously achieved, with excellent gray coverage and outstanding fastness properties, i.e., a highly natural shade with a long-lasting color result.

[0050] As mentioned at the beginning, direct dyes are dye molecules that adhere directly to the hair and do not require an oxidative process to develop the color.

[0051] Preferred direct-drawing dyes include nitrophenylenediamines, nitroaminophenols, azo dyes, anthraquinones, and indophenols, and are preferably selected from the group of dyes known by the international names or trade names HC Yellow 2, HC Yellow 4, HC Yellow 5, HC Yellow 6, HC Yellow 12, Acid Yellow 1, Acid Yellow 10, Acid Yellow 23, Acid Yellow 36, Basic Yellow 57, Basic Yellow 87, HC Orange 1, Disperse Orange 3, Acid Orange 7, Basic Orange 31, HC Red 1, HC Red 3, HC Red 10, HC Red 11, HC Red 13, HC Red BN, Acid Red 33, Acid Red 52, Pigment Red 57:1, Basic Red 51, Basic Red 76, HC Blue 2, HC Blue 12, HC Blue 16, Disperse Blue 3, Acid Blue 7. Basic Blue 99, Acid Green 50, HC Violet 1, Disperse Violet 1, Disperse Violet 4, Acid Violet 43, Disperse Black 9, Acid Black 1, Acid Black 52, Basic Brown 16 and Basic Brown 17 as well as 1,4-diamino-2-nitrobenzene, 2-amino-4-nitrophenol, 1,4-Bis-(β-hydroxyethyl)-amino-2-nitrobenzene,3-Nitro-4-(β-hydroxyethyl)-aminophenol, 2-(2-Hydroxyethyl)amino-4,6-dinitrophenol, 1-(2'-Hydroxyethyl)amino-4-methyl-2-nitrobenzol, 1-Amino-4-(2-hydroxyethyl)-amino-5-chlor-2-nitrobenzol, 4-Amino-3-nitrophenol, 1-(2-Ureidoethyl)amino-4-nitrobenzol, 4-Amino-2-nitrodiphenylamin-2'-carbonsäure, 6-Nitro-1,2,3,4-tetrahydrochinoxalin, 2-Hydroxy-1,4-naphthochinon, Hydroxyethyl-2-nitro-toluidin, Pikraminsäure und deren Salze, 2-Amino-6-chlor-4-nitrophenol, 4-Ethylamino-3-nitrobenzoesäure und 2-Chlor-6-ethylamino-1-hydroxy-4-nitrobenzol.,

[0052] The direct-drawing dye is typically present in the formulation according to the invention in an amount of 0.001-5 wt.%, preferably 0.05-3 wt.%, preferably 0.1-2 wt.%, preferably 0.1-1.2 wt.%, preferably in an amount of about 0.1 wt.%, 0.2 wt.%, 0.3 wt.%, 0.4 wt.%, 0.5 wt.%, 0.6 wt.%, 0.7 wt.%, 0.8 wt.%, 0.9 wt.%, 1.0 wt.%, 1.1 wt.%, 1.2 wt.%, 1.3 wt.%, 1.4 wt.%, 1.5 wt.%, 1.6 wt.%, 1.7 wt.%, 1.8 wt.%, 1.9 wt.%, 2.0 wt.%, in each case based on the total weight of the formulation.

[0053] In a preferred embodiment, the direct-drawing dye is selected from the group consisting of 2-Amino-6-chloro-4-nitrophenol, 1,4-Bis-(β-hydroxyethyl)-amino-2-nitrobenzene, Basic Yellow 57, Basic Red 76, Basic Brown 16, Basic Brown 17, Basic Blue 99, HC Blue 2, HC Blue 12, HC Blue 16 and Acid Violet 43.

[0054] In a particularly preferred embodiment of the invention, the direct-drawing dye is HC Blue 2.

[0055] In a further particularly preferred embodiment, the formulation according to the invention contains 5,6-dihydroxyindole as a dye precursor, caffeine as a xanthine derivative, and HC Blue 2 as a direct-drawing dye. Here, 5,6-dihydroxyindole is present in an amount of 0.05–0.6 wt.%, caffeine in an amount of 0.8–1.2 wt.%, and the direct-drawing dye in an amount of 0.1–1.2 wt.%, each based on the total weight of the formulation.

[0056] Furthermore, the cosmetic formulation according to the invention can contain all additives (i.e., active ingredients, additives and excipients) known in such preparations.

[0057] In one embodiment, the cosmetic formulation comprises a surfactant. The surfactant can be anionic, non-ionic, cationic, or zwitterionic. Preferably, the surfactant is an anionic or non-ionic surfactant, in particular a mild (i.e., especially skin-friendly) anionic or non-ionic surfactant. According to the invention, non-ionic surfactants are used especially because of their very good emulsifying properties and their excellent skin-care properties. Anionic surfactants are preferred because they exhibit particularly high cleaning performance. Therefore, they are especially suitable for cleansing formulations such as shampoos. Cationic surfactants possess excellent hair-care properties and are used according to the invention especially in hair-care formulations such as conditioners, shampoos, and treatments.

[0058] The formulation according to the invention preferably contains surfactants in an amount of 2 to 40 wt.%, in particular 5 to 30 wt.%, preferably 7 to 20 wt.%, and most preferably 10 to 17 wt.%, based on the total weight of the formulation. Suitable amounts of surfactant are: 8 wt.%; 9 wt.%; 10 wt.%; 11 wt.%; 12 wt.%; 13 wt.%; 14 wt.%; 15 wt.%; 16 wt.%; 17 wt.%; 18 wt.%; 19 wt.%; 20 wt.%; 21 wt.%; 22 wt.%; 23 wt.%; 24 wt.%; 25 wt.%, based on the total weight of the formulation. The cosmetic formulation of the invention most preferably contains one or more anionic surfactants in an amount of 0.1 to 20 wt.%, preferably 1 to 17 wt.%, and most preferably 5 to 15 wt.%, in each case based on the total weight of the formulation. Suitable amounts of anionic surfactant are: 1 wt.%, 2 wt.%, 3 wt.%; 4 wt.%, 5 wt.%, 6 wt.%, 7 wt.%, 8 wt.%, 9 wt.%, 10 wt.%, 11 wt.%, 12 wt.%.-%, 13 wt.%, 14 wt.%, 15 wt.%, 16 wt.%, 17 wt.%, 18 wt.%, 19 wt.%, 20 wt.%, each based on the total weight of the formulation. At these amounts, the surfactants exhibit particularly high cleaning performance and are extremely well-tolerated by skin, scalp, and hair.

[0059] The surfactants of the present invention are described, among other places, in the book "Surfactants and interfacial phenomena", by Milton Rosen and Joy Kunjappu, John Wiley & Sons, Inc.-Verlag, 2012, 4th edition.

[0060] In a preferred embodiment, the surfactant is an anionic surfactant selected from alkyl carboxylates, alkyl sulfonates, alkyl sulfates, alkyl ether sulfates, alkyl phosphates, alkyl sarcosinates, alkyl taurates, amino acid surfactants, and mixtures thereof. Particularly preferred is a surfactant selected from alkyl carboxylates, alkyl sulfates, alkyl sarcosinates, alkyl taurates, alkyl glutamate (such as sodium cocoyl glutamate / disodium cocoyl glutamate), alkyl glycinate, alkyl alaninate (such as sodium cocoyl alaninate), and mixtures thereof. Also preferred, due to their cleaning performance, are fatty alcohol polyglycerol ether sulfates, monoglyceride sulfates, mono- and / or dialkyl sulfosuccinates, fatty acid isethionates, and α-olefin sulfonates.

[0061] Alkyl carboxylates have the generic formula RCO₂M, alkyl sulfates have the generic formula ROSO₃M, alkyl sarcosinates have the generic formula RC(O)N(CH₃)CH₂CO₂M, and alkyl taurates have the generic formula RC(O)N(CH₃)CH₂CH₂SO₃M, where R is a C₄-C₂₆ alkyl or C₄-C₂₆ alkenyl and M is a water-soluble cation such as ammonium, sodium, or potassium. Preferably, M is a sodium cation. Preferably, it is a pure C₁₂-C₁₆ alkyl or a C₁₂-C₁₈ alkyl.

[0062] In one embodiment, the surfactant is a nonionic surfactant (also referred to as a nonionic emulsifier). Non-limiting examples include glycerol fatty acid esters, fatty alcohols, polyoxyethylene ethers of one or more fatty alcohols, alkoxylated fatty acid alkyl esters, polyglycerol ethers of fatty alcohols, polyglycerol esters of fatty acids, polyethylene glycol and / or polypropylene glycol ethers, fatty acid amides, alkylphenol polyglycol ethers, amine oxides, and alkyl polyglucosides.

[0063] In one embodiment, the surfactant is selected from the group consisting of glycerol fatty acid esters, fatty alcohols, polyoxyethylene ethers of one or more fatty alcohols, polyglycerol ethers of fatty alcohols, polyglycerol esters of fatty acids and mixtures thereof.

[0064] In the present invention, the term "glycerol fatty acid ester" refers to a glycerol mono- or glycerol di-fatty acid ester. Glycerol di-fatty acid esters have the formula R<3<-COO-(CH2CH(OH)CH2)-OOR<4< or R3<-COO-(CH2CH(OOR4<)CH2)-OH. Glycerol mono-fatty acid esters have the formula R<3<-COO-(CH2CH(OH)CH2)-OH or HO-(CH2CH(OOR3<)CH2)-OH. R3 and R4 are independently selected from C6-C28 alkyl and C6-C28 alkenyl, respectively. Glycerol mono-fatty acid esters contain a glycerol group linked to a single fatty acid via an ester bond. Examples include glycerol monostearate, glycerol monobehenate, glycerol monocaprylate, glycerol monocaprate and glycerol monolaurate.

[0065] Saturated fatty alcohols are compounds of the formula H 3 C-(CH 2 ) n -CH 2 -OH, where n is an integer between 4 and 20, preferably an integer between 6 and 16.

[0066] Polyoxyethylene ethers are compounds of the formula R5(OC2H3)nOH, where R5 is selected from C6-C28 alkyl, C6-C28 alkenyl, substituted and unsubstituted phenoxy groups; and n is an integer greater than 1. Preferably, the polyoxyethylene ether of one or more fatty alcohols is selected from the group consisting of steareth-2, steareth-21, macrogol cetostearyl ether 12, ceteareth-25, macrogol cetostearyl ether 20, and mixtures thereof. Even more preferably, the polyoxyethylene ether is a compound selected from the group consisting of ceteareth-25, macrogol cetostearyl ether 20, and mixtures thereof.

[0067] The term "polyglycerol ethers of fatty alcohols" refers to a compound of the formula R6O-(C3H6O2)n-H, where R6 is a branched or linear C6-C28 alkyl or C6-C28 alkenyl and n is an integer greater than 1, preferably an integer from 2 to 10. It is preferred that the formulation contains 0.01 to 15.0 wt%, 0.1 to 10.0 wt%, or 1 to 5.0 wt% polyglycerol ethers.

[0068] The term "polyglycerol esters of fatty acids" refers to compounds containing both a polyglycerol unit and at least one C6-C26 alkyl or C6-C26 alkenyl carboxylic acid unit. These compounds may have the formula R7< -R8< -(C3H6O2)n-H, where R7< is a C6-C26 alkanoate or C6-C26 alkenoate residue and R8< is a suitable linker molecule or a direct bond. Thus, the polyglycerol unit and the C6-C26 alkyl or C6-C26 alkenyl carboxylic acid unit may be directly linked by an ester bond or may contain a linker unit connecting these two units.Nicht einschränkende Beispiele für diese Gruppe sind Polyglyceryl-3-methylglucosedistearat, Polyglycerinpolycrinoleat, Polyglyceryl-Dimerat-Isostearat, Polyglyceryl-2-Laurat, Polyglyceryl-2-Sesquiisostearat, Polyglyceryl-3-Distearat (Cremophor GS 32), Polyglyceryl-3-Oleat, Polyglyceryl-3-Methylglykose-Distearat, Polyglyceryl-4-Caprat (Polyglycerolcaprat T2010190), Polyglyceryl-4-Diisostearat / Polyhydroxystearat / Sebacat (Isolan GPS) und Polyglyceryl-4-Isostearat.

[0069] In one embodiment, the surfactant comprises a cationic surfactant, such as a quaternary surfactant. Quaternary surfactants contain at least one nitrogen atom covalently bonded to four alkyl or aryl groups. This results in a positive charge, independent of pH. Advantageous examples include alkyl betaine, alkylamidopropyl betaine, and alkylamidopropyl hydroxysulfaine.The cationic surfactants used according to the invention can preferably be selected from the group of quaternary ammonium compounds, in particular benzyltrialkylammonium chlorides or bromides, such as benzyldimethylstearylammonium chloride, furthermore alkyltrialkylammonium salts, for example cetyltrimethylammonium chloride or bromide, alkyldimethylhydroxyethylammonium chlorides or bromides, dialkyldimethylammonium chlorides or bromides, alkylamidethyltrimethylammonium ether sulfates, alkylpyridinium salts, for example laurylpyrimidinium or cetylpyrimidinium chloride, imidazoline derivatives and compounds with cationic character such as amine oxides, for example alkyldimethylamine oxides or alkylaminoethyldimethylamine oxides. The use of cetyltrimethylammonium salts is particularly advantageous.

[0070] In a further embodiment, the formulation according to the invention contains at least one additive. Preferably, the additives are those commonly used in shampoos, conditioners, and emulsions for treating the skin, scalp, and hair. The at least one additive can be present in a proportion of 0.01 wt.% to 12.0 wt.%, more preferably from 0.25 wt.% to 10.0 wt.%, and particularly from 1.0 wt.% to 7.0 wt.%.

[0071] The at least one additive may also be selected from the group consisting of hair conditioning agents, emollients, preservatives, stabilizers, fragrances, antioxidants, rheology modifiers, thickeners, conditioning agents, dyes, pearlescent agents, lightening agents, solvents, strengthening compounds, anti-dandruff agents, vitamins, alkalizing agents or pH adjusters and combinations thereof.

[0072] Hair conditioning products can reduce static electricity in the hair by neutralizing the electrical charge on its surface. Examples of hair conditioning products include quaternary ammonium compounds.

[0073] Emollients, also called re-fatting agents or superfatting agents, are lipophilic substances that can prevent a disruptive effect on the epidermal barrier function. Examples of emollients include lanolin, squalene, liquid paraffin, vegetable oils, silicones, and cetyl palmitate.

[0074] Preservatives are substances used for preservation by killing microorganisms that degrade the formulation and / or inhibiting their growth. Preferably, the preservatives can be selected from the group consisting of benzoic acid, benzoic acid derivatives, sorbic acid, sorbic acid derivatives, salicylic acid, salicylic acid derivatives, phenoxyethanol, parabens, and combinations thereof. In a preferred embodiment, sodium benzoate and / or potassium sorbate are used as preservatives in the formulation according to the invention. Sodium benzoate releases benzoic acid and potassium sorbate releases sorbic acid in a slightly acidic environment. Both acids are attributed with antimicrobial properties.

[0075] Stabilizers can protect light-sensitive components from radiation and are preferably UV absorbers such as benzophenone derivatives.

[0076] The addition of fragrances can give the formulation a pleasant scent. Examples include perfumes familiar to professionals.

[0077] An antioxidant is a chemical compound that slows down or completely prevents the oxidation of other components in the formulation according to the invention. Examples of suitable antioxidants include citric acid, ascorbic acid, sodium sulfite, and butylhydroxyanisole.

[0078] Rheology modifiers and thickening agents can help to improve the application properties of the formulation according to the invention. The addition of sodium chloride (table salt) can be considered as a rheology modifier and thickening agent. The addition of sodium chloride can influence the flowability of the formulation according to the invention within certain limits and adjust it to the required level. Naturally occurring gelling agents can also be used as thickeners, preferably selected from agar, xanthan gum, cellulose and / or cellulose derivatives, or alginic acid.

[0079] For the purposes of this application, "care products" are defined as substances that care for the hair and / or scalp. Hydrolyzed wheat protein, panthenol, and allantoin have a conditioning effect on the scalp and hair. Hydrolyzed wheat protein primarily has moisturizing properties.

[0080] The formulation according to the invention may also contain dyes, for example to give the formulation an aesthetically pleasing color. For example, CI 47005 may be included as a suitable dye in the formulation according to the invention.

[0081] A solvent or solvent mixture commonly used by those skilled in the art in this field can be employed. Preferred solvents are ethanol or butylene glycol, in particular 1,4-butylene glycol, propylene glycol, and isopropyl alcohol. Ethanol or propylene glycol is preferred. These solvents may preferably be present in the formulation according to the invention in an amount of 0.1 to 70% by weight. A particularly preferred amount is 0.1 to 5.0% by weight.

[0082] Strengthening compounds are preferably selected from the group consisting of waxes, synthetic polymers, and mixtures thereof. Suitable strengthening compounds are known to those skilled in the art and are described, for example, in Goddard, E. Desmond; Gruber, James V. (1999), "Principles of polymer science and technology in cosmetics and personal care", Series: Cosmetic science and technology series : v. 22., New York (Marcel Dekker, INC.); Schrader, Karlheinz (1989), "Grundlagen und Rezepturen der Kosmetika" (2nd edition), Chapter 3.7, Heidelberg (Hüthig); and Scott, Richard (2017), "ingredients focus: cosmetic waxes and butters", Personal Care Europe 10(3), 46-47.

[0083] Anti-dandruff agents are used to control excessive dandruff production on the scalp. Suitable anti-dandruff agents are known to those skilled in the art and are described, for example, in Trüeb, RM (2009). "Successfully treating dandruff." Akt Dermatol 35(01 / 02): 19-24; Trueb, RM (2007). "Shampoos: ingredients, efficacy and adverse effects." J. Dtsch. Dermatol. Ges. 5(5): 356-365; Sanfilippo, A. and J. English (2006). "An overview of medicated shampoos used in dandruff treatment." P AND T 31(7): 396; and Futterer, E. (1981). "Evaluation of efficacy of antidandruff agents." J Soc Cosmet Chem 32: 327-338.

[0084] Vitamins and minerals such as niacinamide (vitamin B3), vitamin E, and zinc are used to promote hair growth and repair damage. Suitable vitamins and minerals are known to experts and are described, for example, in Pietrzik K, Golly I, Loew D, Handbuch Vitamine (Handbook of Vitamins), Elsevier GmbH, Urban & Fischer Verlag, Munich 2008; H. Lautenschläger, Vitamine in der Kosmetik (Vitamins in Cosmetics), medical Beauty Forum 2020 (3), 14-17; and Martini MC, Chivot M., Peyrefitte G., Lehrbuch Kosmetik: Grundlagen - Grundstoffe - Grundtechniken (Textbook of Cosmetics: Fundamentals - Basic Ingredients - Basic Techniques), Hogrefe AG, Bern 2001.

[0085] Alkalizing agents or pH adjusters are used to adjust the pH of the formulation to a desired range. Suitable alkalizing agents or pH adjusters include, among others, sodium hydroxide, monoethanolamine (0.1–5%), phosphoric acid, and citric acid.

[0086] Examples of compositions are shown in the following table: ingredient Quantity in wt.%% Aqua [Water] ad 100 Sodium lauryl ether sulfate 5-15 Sodium myreth sulfate 0-5 Sodium cocoamphoacetate 0-5 Laureth-2 0-5 Cocoamidopropyl betaine 0-5 Disodium lauryl sulfosuccinate 0-5 Sodium lauroylglutamate 0-5 Panthenol 0-5 caffeine 0,1-5 Sodium chloride 0-5 Phenoxyethanol 0-5 Wheat protein hydrolysate 0-3 Cocoglucoside 0-3 Glyceryl oleate 0-3 Phosphoric acid 0-3 Sodium benzoate 0-3 PEG-120 Methylglucose dioleate 0-3 Potassium sorbate 0-3 HC Blue 2 0,1-2 Allantoin 0-3 PEG-40 hydrogenated castor oil 0-3 menthol 0-2 Polyquaternium-7 0-2 Sodium hydroxide 0-2 Disodium EDTA 0-2 Dihydroxyindol 0,01-2 Tocopherol 0-2 citric acid 0-2 Niacinamide 0-2 Zinc PCA 0-2 Dye / coloring agent 0-2

[0087] According to the invention, the composition is applied topically. Topical application is understood to mean external application, in particular local, external application. Compositions according to the invention are preferably hair care products (i.e., treatment products such as shampoos, conditioners, or treatments).

[0088] In a preferred embodiment, the formulation according to the invention is in the form of a shampoo, conditioner, treatment or color treatment, in particular as a shampoo or color treatment.

[0089] The cosmetic formulation of the present invention is particularly suitable for the pigmentation and / or repigmentation of keratin fibers.

[0090] Accordingly, in a further embodiment, the present invention relates to the use of the cosmetic formulation containing a dye precursor selected from the group consisting of the indolin derivatives and indole derivatives defined in claim 1, the xanthine derivative caffeine and at least one direct dye, as a bioactive substance for the pigmentation and / or repigmentation of keratin fibers.

[0091] For the purposes of the present invention, "keratin fibers" are understood to mean hair, in particular human hair. The term "human hair" specifically includes head hair and beard hair.

[0092] In a preferred embodiment, the present invention relates to the use of the cosmetic formulation for the pigmentation and / or repigmentation of human hair.

[0093] The formula is preferably applied to wet or dry hair and rinsed out after a dwell time of between 1 and 30 minutes.

[0094] The cosmetic formulation according to the invention for the pigmentation and / or repigmentation of keratin fibers, in particular human hair, causes the hair to be slowly and gently permanently colored and at the same time stimulates the keratinocytes in the hair roots so that they produce more natural pigment again.

[0095] In a further embodiment, the invention relates to the use of the cosmetic formulation for the pigmentation and / or repigmentation of human hair, wherein the hair is slowly and gently permanently colored and at the same time the keratinocytes in the hair roots are stimulated so that they produce more natural pigment again.

[0096] In a further embodiment, the invention relates to a method for the pigmentation and / or repigmentation of keratin fibers, in particular human hair, wherein the cosmetic formulation according to the invention is applied to the hair and the coloring process then takes place. The coloring is effected solely by atmospheric oxygen; no further oxidizing agent is required.

[0097] The following formulations are intended to clarify the invention without limiting it to the specific examples. Character description

[0098] Figure 1 Comparison photos of strands washed with example formula 2 (D1 / D2) or comparison formula (E1 / E2). Figure 2 Comparison of the color preview for the two shampoos used: Example formula 2 and comparison formula. Figure 3 Change in color depth when using shampoos example formula 2 or comparison formula as absolute values ​​dL* Figure 4 Total color change dE* when using shampoos example formula 2 or comparison formula Figure 5 Change in color depth when washing with coloring shampoo (5 washes) or rinsing with a neutral formula (14 washes) Figure 6 Change in color depth when washing with coloring shampoo (10 washes) or rinsing with a neutral formula (15 washes) Figure 7 Change in color depth when washing with coloring shampoo (15 washes) or rinsing with a neutral formula (15 washes) Figure 8Comparison of the color change for the two shampoos used on a single strand each after 15 washes followed by 15 rinses. Figure 9 Comparison of the color preview for the shampoos used: Example formula 1, Example formula 2, and Comparison formula, each on a single strand after 15 washes. Figure 10 Change in color depth when using shampoos example formula 1 or example formula 2 or comparison formula as absolute values ​​dL* Figure 11 Total color change dE* when using shampoos example formula 1 or example formula 2 or comparison formula Experimental section Recipes

[0099] The following recipes were produced using methods known to experts. Comparative formula

[0100] The comparison formulation contains caffeine as a xanthine derivative and HC Blue 2 as a direct-drawing dye. ingredient Quantity in wt.% Aqua [Water] ad 100 Sodium lauryl ether sulfate 11,5 Sodium cocoamphoacetate 3 Cocamidopropyl betaine 1,7 caffeine 1,1 Panthenol 0,92 Sodium chloride 1 Phenoxyethanol 0,7 Cocoglucoside 0,5 Glyceryl oleate 0,5 Phosphoric acid 0,4 PEG-120 Methylglucose dioleate 0,3 HC Blue 2 0,22 menthol 0,2 Polyquaternium-7 0,2 Sodium hydroxide 0,15 Niacinamide 0,1 Zinc PCA 0,1 Dye / coloring agent 0,1 citric acid 0,06 Example recipe 1 (outside the scope of the invention)

[0101] Example formulation 1 contains dihydroxyindole and caffeine as a xanthine derivative. ingredient Quantity in wt.% Aqua [Water] ad 100 Sodium lauryl ether sulfate 8,0 Sodium myreth sulfate 2,5 Laureth-2 2 Panthenol 1,7 Sodium chloride 1,65 Disodium lauryl sulfosuccinate 1,5 Sodium lauroylglutamate 1,3 caffeine 1,1 PEG-120 Methylglucose dioleate 0,75 Wheat protein hydrolysate 0,7 Dihydroxyindol 0,49 Allantoin 0,4 citric acid 0,38 Sodium benzoate 0,36 Propylene glycol 0,3 Potassium sorbate 0,3 PEG-40 hydrogenated castor oil 0,18 Cocoglucoside 0,18 Glyceryl oleate 0,17 Polyquaternium-7 0,17 Disodium EDTA 0,15 Zinc PCA 0,1 Niacinamide 0,1 Tocopherol 0,06 Example recipe 2

[0102] Example formulation 2 contains dihydroxyindole, caffeine as a xanthine derivative and HC Blue 2 as a direct-drawing dye. ingredient Quantity in wt.% Aqua [Water] ad 100 Sodium lauryl ether sulfate 11,5 Sodium cocoamphoacetate 3 Cocamidopropyl betaine 1,7 caffeine 1,1 Panthenol 0,92 Sodium chloride 1 Phenoxyethanol 0,7 Cocoglucoside 0,5 Glyceryl oleate 0,5 Phosphoric acid 0,4 PEG-120 Methylglucose dioleate 0,3 HC Blue 2 0,22 menthol 0,2 Polyquaternium-7 0,2 Sodium hydroxide 0,15 Dihydroxyindol 0,2 Niacinamide 0,1 Zinc PCA 0,1 Dye / coloring agent 0,1 citric acid 0,06 Example recipe 3

[0103] Example formulation 3 contains dihydroxyindole, caffeine as a xanthine derivative and HC Blue 2 as a direct-drawing dye. ingredient Quantity in wt.% Aqua [Water] ad 100 Sodium lauryl ether sulfate 9 Sodium myreth sulfate 3 Sodium cocoamphoacetate 1 Laureth-2 2 Disodium lauryl sulfosuccinate 1 Sodium lauroylglutamate 2 caffeine 0,9 Sodium chloride 1 Wheat protein hydrolysate 0,7 Phosphoric acid 0,3 Sodium benzoate 0,5 Potassium sorbate 0,2 HC Blue 2 1 Allantoin 0,4 PEG-40 hydrogenated castor oil 0,4 Polyquaternium-7 0,2 Disodium EDTA 0,2 Dihydroxyindol 0,3 Tocopherol 0,02 Example recipe 4

[0104] Example formulation 4 contains dihydroxyindole, caffeine as a xanthine derivative and HC Blue 2 as a direct-drawing dye. ingredient Quantity in wt.% Aqua [Water] ad 100 Sodium lauryl ether sulfate 11 Sodium myreth sulfate 2 Laureth-2 3 Cocoamidopropyl betaine 2 Disodium lauryl sulfosuccinate 1 Sodium lauroylglutamate 1 Panthenol 0,5 caffeine 1 Sodium chloride 0,9 Phenoxyethanol 0,5 Wheat protein hydrolysate 0,5 Cocoglucoside 0,3 Glyceryl oleate 0,4 Phosphoric acid 0,25 Sodium benzoate 0,2 PEG-120 Methylglucose dioleate 0,1 Potassium sorbate 0,5 HC Blue 2 0,8 Allantoin 0,1 PEG-40 hydrogenated castor oil 0,2 menthol 0,2 Sodium hydroxide 0,1 Disodium EDTA 0,2 Dihydroxyindol 0,1 citric acid 0,03 Niacinamide 0,2 Zinc PCA 0,2 Dye / coloring agent 0,1 Example recipe 5 (outside the invention)

[0105] Example formulation 5 contains dihydroxyindole and caffeine as a xanthine derivative. ingredient Quantity in wt.% Aqua [Water] ad 100 Sodium lauryl ether sulfate 12 Sodium cocoamphoacetate 2 Cocoamidopropyl betaine 2 Panthenol 1 caffeine 1,1 Sodium chloride 0,9 Phenoxyethanol 0,8 Cocoglucoside 0,4 Glyceryl oleate 0,3 Phosphoric acid 0,3 PEG-120 Methylglucose dioleate 0,2 menthol 0,2 Polyquaternium-7 0,1 Sodium hydroxide 0,2 Disodium EDTA 0,1 Dihydroxyindol 0,2 citric acid 0,06 Niacinamide 0,2 Zinc PCA 0,2 Dye / coloring agent 0,5 Neutral formula

[0106] The neutral formula contains neithercaffeine still DHI still HC Blue 2. ingredient Quantity in wt.% Aqua [Water] ad 100 Sodium lauryl ether sulfate 10 Laureth-2 1,9 Disodium lauryl sulfosuccinate 1,5 Sodium chloride 1,3 Sodium lauroylglutamate 1,3 Panthenol 1,2 PEG-120 Methylglucose dioleate 0,5 Wheat protein hydrolysate 0,49 citric acid 0,4 Sodium citrate 0,35 Propylene glycol 0,2 menthol 0,2 PEG-40 hydrogenated castor oil 0,2 Potassium sorbate 0,19 Polyquaternium-7 0,17 Disodium EDTA 0,11 Sodium benzoate 0,1 Zinc PCA 0,06 Niacinamide 0,055 Tocopherol 0,032 Dye / coloring agent 0,0005 Application examples

[0107] To evaluate the dyeing performance in terms of quality, intensity and duration, the following washing tests (wash-on and wash-out tests) were carried out. Application example 1

[0108] Kerling strands were subjected to a wash-up test with a shampoo containing 5,6-DHI, caffeine and HC Blue 2 (Example Recipe 2) or with a shampoo containing HC Blue 2 and caffeine (Comparison Recipe) to investigate the coloring performance in terms of quality and intensity. Washing protocol:

[0109] Moisten strands with lukewarm water for 30 seconds, then squeeze out excess water between two fingers. Massage a total of 5 g of shampoo into 5 strands for 1 minute. Leave on for a total of 5 minutes. Rinse with lukewarm water for 1 minute, then squeeze out excess water using a paper towel. Comb through, then air dry, spreading the strands out individually. The next day, scan the strands with the Konica (Konica-Minolta Spectrophotometer CM600d, measuring geometry d / 8°, Specular Component Excluded (SCE), standard illuminant D65, field of view 10°) (photograph sample strands every 5 washes); then repeat the washing cycle. Hair strands used:

[0110] Kerling white selected, adhesive braid 2 cm wide, 12 cm long, 3 g / pc., Ch. 1719 Shampoos used:

[0111] Example recipe 2 Strands D1-D5 Comparative formula Highlights E1-E5

[0112] Five strands of each product were used, and 28 wash cycles were performed.

[0113] Figure 1 shows a comparison of strands D1 / D2 treated with example formula 2 with strands E1 / E2, which were treated with the comparison formula.

[0114] The comparison of the color preview for the two shampoos used is in Figure 2 depicted. The Figures 3 and 4 show the change in color depth as absolute values ​​dL* ( Figure 3 ) or as total color change dE* ( Figure 4 The figures show the gradual development of the color effect with repeated application, as well as the improved coloring result compared to the reference formula. Application example 2

[0115] Kerling strands were subjected to a wash-in and wash-out test with a shampoo containing 5,6-DHI, caffeine and HC Blue 2 (Example Recipe 2) or with a shampoo containing HC Blue 2 and caffeine (Comparison Recipe) to investigate the coloring performance in terms of quality, intensity and duration. Washing protocol:

[0116] Moisten strands with lukewarm water for 30 seconds, then squeeze out excess water between two fingers. Massage a total of 5 g of shampoo into 5 strands for 1 minute. Leave on for a total of 5 minutes. Rinse with lukewarm water for 1 minute, then squeeze out excess water using a paper towel. Comb through, then air dry, spreading the strands out individually. The next day, scan the strands with the Konica (Konica-Minolta Spectrophotometer CM600d, measuring geometry d / 8°, Specular Component Excluded (SCE), standard illuminant D65, field of view 10°), photograph them, and then repeat the washing cycle. Hair strands used:

[0117] Kerling white selected, adhesive weft 2cm wide, 12cm long Coloring shampoos used:

[0118] Example recipe 2 Highlights B1-B15 Comparative formula Strands C1-C15

[0119] The neutral formula was used for rinsing.

[0120] For each product, 15 strands were treated in portions of 5.

[0121] The color change was tracked over the following wash and rinse cycles: Five washes each with color-depositing shampoo for rinsing, followed by 14 washes with a neutral formula ( Figure 5 ) 10 washes each with color-depositing shampoo for rinsing, followed by 15 washes with a neutral formula ( Figure 6 ) 15 washes each with color-depositing shampoo for rinsing, followed by 15 washes with a neutral formula ( Figure 7 ).

[0122] The Figures 5-7 Each figure shows the change in color depth when washing with coloring shampoo or rinsing with a neutral formula according to the protocols specified above. Figure 8Figure 1 shows the comparison of the color change for the two shampoos used on a single strand of hair after 15 washes followed by 15 rinses, measured with the Konica measuring device (Konica-Minolta Spectrophotometer CM600d, measuring geometry d / 8°, Specular Component Excluded (SCE), standard illuminant D65, field of view 10°). The figures illustrate the gradual development of the color effect with repeated application and the improved coloring result compared to the reference formulation. Furthermore, after discontinuing treatment with the shampoo according to the invention, the color effect lasts longer than when using the reference formulation. Application example 3

[0123] White Virgin strands (Imhair) were subjected to a wash-up test with a shampoo containing 5,6-DHI and caffeine (example formula 1), with a shampoo containing 5,6-DHI, caffeine and HC Blue 2 (example formula 2), and with a shampoo containing HC Blue 2 and caffeine (comparative formula) to investigate the coloring performance in terms of quality and intensity. Washing protocol:

[0124] Moisten strands with lukewarm water for 30 seconds, then squeeze out excess water between two fingers. Massage a total of 2 g of shampoo into 3 strands for 30 seconds. Leave on for a total of 5 minutes. Rinse with lukewarm water for 1 minute. Comb and air dry. The next day, scan the strands with the Konica applicator, take photos, then repeat the washing cycle. Hair strands used:

[0125] White Virgin (Imhair) Shampoos used:

[0126] Example recipe 1 Strands 1-3 Example recipe 2 Strands 4-6 Comparative formula Strands 7-9

[0127] Three strands of each product were used, and 15 wash cycles were performed.

[0128] The comparison of the color preview for the shampoos used is for a single strand of hair in each case. Figure 9 depicted. The Figures 10 and 11 show the change in color depth as absolute values ​​dL* ( Figure 10 ) or as total color change dE* ( Figure 11 The figures show the gradual development of the color effect with repeated application, as well as the improved coloring result compared to the reference formula. Application example 4

[0129] To examine the color change over time, strands of Kerling White and Imhair bleached hair were colored with 10 g of sample formula 2 for 15 minutes, rinsed for 1 minute, and left to air dry for 1.5 hours (residual moisture was then blow-dried). Measurements were taken on the day of treatment after a 15-minute processing time (initial color) and after 1, 2, 3, 8, 9, 10, 11, 14, and 15 days. L*(D65) a*(D65) b*(D65) dL*(D65) da*(D65) db*(D65) dE*ab(D65) Kerling strand, white 76,58 2,15 21 ------ ------ ------ ------ Starting shade (after 15 minutes of exposure time) 62,32 1,58 5,02 -14,27 -0,57 -15,98 21,43 read after 1 day 62,11 2,05 5,23 -14,48 -0,1 -15,77 21,41 read into 2D 63,06 2,22 4,59 -13,52 0,07 -16,42 21,27 read into 3D 63,02 2,44 5,09 -13,56 0,29 -15,91 20,91 read after 8 days 62,95 2,53 5,57 -13,64 0,38 -15,44 20,6 read after 9d 62,86 2,35 5,5 -13,73 0,21 -15,51 20,71 Read in after 10 days 62,63 2,57 5,87 -13,95 0,42 -15,13 20,58 read after 11d 62,59 2,61 5,47 -14 0,46 -15,53 20,91 Read in after 14 days 63,16 3,1 6,34 -13,43 0,95 -14,67 19,91 Read in after 15 days 63,59 3,16 6,26 -12,99 1,02 -14,74 19,68 L*(D65) a*(D65) b*(D65) dL*(D65) da*(D65) db*(D65) dE*ab(D65) Strand of hair, bleached 76,9 3,5 24,61 ------ ------ ------ ------ Starting shade (after 15 minutes of exposure time) 51,51 1,01 2,73 -25,38 -2,49 -21,88 33,61 read after 1 day 51,71 1,6 2,8 -25,19 -1,9 -21,82 33,38 read into 2D 52,11 1,61 2,79 -24,78 -1,89 -21,82 33,08 read into 3D 51,57 2,06 3,23 -25,33 -1,43 -21,38 33,17 read after 8 days 52,21 2,22 3,78 -24,68 -1,28 -20,84 32,33 read after 9d 51,98 2,13 3,84 -24,92 -1,36 -20,78 32,47 Read in after 10 days 52 2,29 4,16 -24,9 -1,21 -20,46 32,24 read after 11d 52,11 2,29 4,16 -24,79 -1,21 -20,46 32,16 Read in after 14 days 52,69 2,65 4,86 -24,21 -0,84 -19,75 31,25 Read in after 15 days 53,23 2,68 5,01 -23,67 -0,82 -19,61 30,74

[0130] The measured values ​​demonstrate a shift in nuances – also visually perceptible – from the original graphite to a more natural, brownish hue.

Claims

1. Cosmetic formulation containing a dye precursor, selected from the group consisting of derivatives of 5,6-dihydroxyindole of formula (I), wherein, independently of one another, R1 means hydrogen, a C1-C4 alkyl group or a C1-C4 hydroxyalkyl group, R2 means hydrogen or a -COOH group, wherein the -COOH group also being able to be present as a salt with a physiologically acceptable cation, R3 means hydrogen or a C1-C4 alkyl group, R4 means hydrogen, a C1-C4 alkyl group, an amino group or a group -CO-R6, in which R6 means a C1-C4 alkyl group, and R5 means one of the groups mentioned under R4, or a physiologically acceptable salt of these compounds with an organic or inorganic acid, and derivatives of 5,6-dihydroxyindoline of formula (II), wherein, independently of one another, R1 means hydrogen, a C1-C4 alkyl group or a C1-C4 hydroxyalkyl group, R2 means hydrogen or a -COOH group, wherein the -COOH group also being able to be present as a salt with a physiologically acceptable cation, R3 means hydrogen or a C1-C4 alkyl group, R4 means hydrogen, a C1-C4 alkyl group, an amino group or a group -CO-R6, in which R6 means a C1-C4 alkyl group, and R5 means one of the groups mentioned under R4, or a physiologically acceptable salt of these compounds with an organic or inorganic acid; a xanthine derivative as bioactive substance, wherein the xanthine derivative is caffeine; and at least one direct dye.

2. Cosmetic formulation according to claim 1, wherein the compound of formula (I) is selected from 5,6-dihydroxyindole, N-methyl-5,6-dihydroxyindole, and their physiologically acceptable salts.

3. Cosmetic formulation according to claim 1, wherein the compound of formula (II) is selected from 5,6-dihydroxyindoline, N-methyl-5,6-dihydroxyindoline, and their physiologically acceptable salts.

4. Cosmetic formulation according to any of the claims 1-3, wherein the direct dye is selected from the group consisting of 2-amino-6-chloro-4-nitrophenol, 1,4-bis-(β-hydroxyethyl)-amino-2-nitrobenzene, Basic Yellow 57, Basic Red 76, Basic Brown 16, Basic Brown 17, Basic Blue 99, HC Blue 2, HC Blue 12, HC Blue 16 and Acid Violet 43, preferably HC Blue 2.

5. Non-therapeutic use of the cosmetic formulation according to any of the preceding claims for the repigmentation of keratin fibres, in particular human hair.

6. Use according to claim 5 for the repigmentation of human hair, wherein the formulation is distributed in wet or dry hair and rinsed out again after a residence time of between 1 and 30 minutes.

7. Use according to claim 5 or claim 6 for the repigmentation of human hair, wherein the hair is slowly and gently permanently coloured and at the same time the keratinocytes in the hair roots are stimulated so that they once again increasingly produce natural pigment.

8. Non-therapeutic method for the repigmentation of keratin fibres, in particular human hair, wherein the cosmetic formulation according to any of claims 1-4 is applied to the hair and the colouring subsequently develops.