AGENT FOR REPIGMENTATION OF KERATIN FIBERS, IN PARTICULAR HUMAN HAIR

Abstract

The present invention relates to a cosmetic formulation containing a coloring agent precursor selected from the group that consists of indole derivatives and indoline derivatives, and a xanthine derivative. The invention also relates to the use of the cosmetic formulation for repigmentation of keratin fibers, in particular human hair.

Claims

1. A cosmetic formulation comprising a dye precursor selected from the group consisting of indoline derivatives and indole derivatives, and a xanthine derivative as bioactive ingredient.

2. The cosmetic formulation according to claim 1, wherein the dye precursor is an indole derivative.

3. The cosmetic formulation according to claim 1, wherein the dye precursor is a derivative of 5,6-dihydroxyindole of formula (I), ##STR00004## wherein, independently of each other, R.sup.1 is hydrogen, a C.sub.1-C.sub.4-alkyl group or a C.sub.1-C.sub.4-hydroxyalkyl group, R.sup.2 is hydrogen or a COOH group, whereby the COOH group can also be present as a salt with a physiologically tolerated cation, R.sup.3 is hydrogen or a C.sub.1-C.sub.4-alkyl group, R.sup.4 is hydrogen, a C.sub.1-C.sub.4-alkyl group, an amino group or a group COR.sup.6 in which R.sup.6 is a C.sub.1-C.sub.4-alkyl group, and R.sup.5 is one of the groups mentioned under R.sup.4, or a physiologically tolerated salt of these compounds with an organic or inorganic acid.

4. The cosmetic formulation according to claim 3, wherein the compound of formula (I) is selected from 5,6-dihydroxyindole, N-methyl-5,6-dihydroxyindole and physiologically tolerated salts thereof.

5. The cosmetic formulation according to claim 1, wherein the dye precursor is an indoline derivative.

6. The cosmetic formulation according to claim 1, wherein the dye precursor is a derivative of 5,6-dihydroxyindoline of formula (II), ##STR00005## wherein, independently of each other, R.sup.1 is hydrogen, a C.sub.1-C.sub.4-alkyl group or a C.sub.1-C.sub.4-hydroxyalkyl group, R.sup.2 is hydrogen or a COOH group, whereby the COOH group can also be present as a salt with a physiologically tolerated cation, R.sup.3 is hydrogen or a C.sub.1-C.sub.4-alkyl group, R.sup.4 is hydrogen, a C.sub.1-C.sub.4-alkyl group, an amino group or a group COR.sup.6 in which R.sup.6 denotes a C.sub.1-C.sub.4-alkyl group, and R.sup.5 is one of the groups mentioned under R.sup.4, or a physiologically tolerated salt of these compounds with an organic or inorganic acid.

7. The cosmetic formulation according to claim 6, wherein the compound of formula (II) is selected from 5,6-dihydroxyindoline, N-methyl-5,6-dihydroxyindoline and physiologically tolerated salts thereof.

8. The cosmetic formulation according to claim 1, wherein the xanthine derivative is caffeine.

9. The cosmetic formulation according to claim 1, further comprising at least one direct dye.

10. The cosmetic formulation according to claim 9, wherein the direct dye is selected from the group consisting of 2-amino-6-chloro-4-nitrophenol, 1,4-bis-(-hydroxyethyl)-amino-2-nitrobenzene, Basic Yellow 57, Basic Red 76, Basic Brown 16, Basic Brown17, Basic Blue 99, HC Blue 2, HC Blue 12, HC Blue 16 and Acid Violet 43, preferably HC Blue 2.

11. Use of the cosmetic formulation according to claim 1 for the repigmentation of keratin fibers, in particular human hair.

12. The use according to claim 11 for the repigmentation of human hair, wherein the formulation is distributed in wet or dry hair and is rinsed out again after a dwell time of between 1 and 30 minutes.

13. The use according to claim 11 for the repigmentation of human hair, wherein the hair is permanently colored in a slow and gentle manner and at the same time the keratinocytes in the hair roots are stimulated so that they produce more natural pigment again.

14. A method for repigmenting keratin fibers, in particular human hair, wherein the cosmetic formulation according to claim 1 is applied to the hair and then the coloring is carried out.

Description

DESCRIPTION OF THE FIGURES

[0109] FIG. 1 Comparative photos of strands washed with Example Formulation 2 (D1/D2) and Comparative Formulation (E1/E2), respectively

[0110] FIG. 2 Comparison of the color preview for the used two shampoos Example Formulation 2 and Comparative Formulation, respectively

[0111] FIG. 3 Change in color depth when using the shampoos Example Formulation 2 and Comparative Formulation, respectively, as absolute values dL*

[0112] FIG. 4 Total color change dE* when using the shampoos Example Formulation 2 and Comparative Formulation, respectively

[0113] FIG. 5 Change in color depth when washing on with color shampoo (5 washes) and washing out with neutral formulation (14 washes), respectively

[0114] FIG. 6 Change in color depth when washing on with color shampoo (10 washes) and washing out with neutral formulation (15 washes), respectively

[0115] FIG. 7 Change in color depth when washing on with color shampoo (15 washes) and washing out with neutral formulation (15 washes), respectively

[0116] FIG. 8 Comparison of the color change for the two shampoos used on a single strand after 15 wash-on cycles, followed by 15 wash-out cycles

[0117] FIG. 9 Comparison of the color preview for the used shampoos Example Formulation 1 and Example Formulation 2 and Comparative Formulation, respectively, on a single strand in each case with 15 wash-on cycles

[0118] FIG. 10 Change in color depth when using the shampoos Example Formulation 1 and Example Formulation 2, respectively, and Comparative Formulation, respectively, as absolute values dL*

[0119] FIG. 11 Total color change dE* when using the shampoos Example Formulation 1 and Example Formulation 2, respectively, and Comparative Formulation, respectively

[0120] FIG. 12 Comparison of the color preview for the used shampoos Example Formulation 6, and Example Formulation 7, respectively, and Example Formulation 8, respectively, on a single strand at 15 wash-on cycles in each case

[0121] FIG. 13 Change in color depth when using the shampoos Example Formulation 6 or Example Formulation 7 or Example Formulation 8 as absolute values dL*

[0122] FIG. 14 Total color change dE* when using the shampoos Example Formulation 6 and Example Formulation 7, respectively, and Example Formulation 8, respectively

[0123] FIG. 15 Comparative photos of strands washed with Example Formulation 6 (DHI-B), Example Formulation 7 (Combi-B) and Example Formulation 8 (Blue-B), respectively, using strand B as an example

EXPERIMENTAL PART

Formulations

[0124] The following formulations have been prepared by means known to a person skilled in the art.

Comparative Formulation

[0125] The Comparative Formulation contains caffeine as xanthine derivative and HC Blue 2 as direct dye.

TABLE-US-00002 Component Quantity in % by weight 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 methyl glucose 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/colorant 0.1 Citric acid 0.06

Example Formulation 1

[0126] Example Formulation 1 contains dihydroxyindole and caffeine as xanthine derivative.

TABLE-US-00003 Component Quantity in % by weight 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 lauroyl glutamate 1.3 Caffeine 1.1 PEG-120 methyl glucose dioleate 0.75 Wheat protein hydrolyzate 0.7 Dihydroxyindole 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 Formulation 2

[0127] Example Formulation 2 contains dihydroxyindole, caffeine as xanthine derivative and HC Blue 2 as direct dye.

TABLE-US-00004 Component Quantity in % by weight 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 methyl glucose dioleate 0.3 HC Blue 2 0.22 Menthol 0.2 Polyquaternium-7 0.2 Sodium hydroxide 0.15 Dihydroxyindole 0.2 Niacinamide 0.1 Zinc PCA 0.1 Dye/colorant 0.1 Citric acid 0.06

Example Formulation 3

[0128] Example Formulation 3 contains dihydroxyindole, caffeine as xanthine derivative and HC Blue 2 as direct dye.

TABLE-US-00005 Component Quantity in % by weight Aqua [water] ad 100 Sodium lauryl ether sulfate 9 Sodium myreth sulfate 3 Sodium cocoamphoacetate 1 Laureth-2 2 Disodium lauryl sulfosuccinate 1 Sodium lauroyl glutamate 2 Caffeine 0.9 Sodium chloride 1 Wheat protein hydrolyzate 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 Dihydroxyindole 0.3 Tocopherol 0.02

Example Formulation 4

[0129] Example Formulation 4 contains dihydroxyindole, caffeine as xanthine derivative and HC Blue 2 as direct dye.

TABLE-US-00006 Component Quantity in % by weight Aqua [water] ad 100 Sodium lauryl ether sulfate 11 Sodium myreth sulfate 2 Laureth-2 3 Cocoamidopropyl betaine 2 Disodium lauryl sulfosuccinate 1 Sodium lauroyl glutamate 1 Panthenol 0.5 Caffeine 1 Sodium chloride 0.9 Phenoxyethanol 0.5 Wheat protein hydrolyzate 0.5 Cocoglucoside 0.3 Glyceryl oleate 0.4 Phosphoric acid 0.25 Sodium benzoate 0.2 PEG-120 methyl glucose 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 Dihydroxyindole 0.1 Citric acid 0.03 Niacinamide 0.2 Zinc PCA 0.2 Dye/colorant 0.1

Example Formulation 5

[0130] Example Formulation 5 contains dihydroxyindole and caffeine as xanthine derivative.

TABLE-US-00007 Component Quantity in % by weight 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 methyl glucose dioleate 0.2 Menthol 0.2 Polyquaternium-7 0.1 Sodium hydroxide 0.2 Disodium EDTA 0.1 Dihydroxyindole 0.2 Citric acid 0.06 Niacinamide 0.2 Zinc PCA 0.2 Dye/colorant 0.5

Example Formulations 6-8

[0131] In contrast to Example Formulation 2, the additional dye for coloring the formulation was completely omitted in Example Formulations 6-8. Example Formulation 6 contains dihydroxyindole and caffeine as xanthine derivative, Example Formulation 7 contains dihydroxyindole, caffeine as xanthine derivative and HC Blue 2 as direct dye and Example Formulation 8 contains caffeine as xanthine derivative and HC Blue 2 as direct dye.

TABLE-US-00008 Example Example Example Example Formulation 2 Formulation 6 Formulation 7 Formulation 8 Quantity in % Quantity in % Quantity in % Quantity in % Component by weight by weight by weight by weight Aqua [water] ad 100 ad 100 ad 100 ad 100 Sodium lauryl ether sulfate 11.5 11.5 11.5 11.5 Sodium cocoamphoacetate 3 3 3 3 Cocamidopropyl betaine 1.7 1.7 1.7 1.7 Caffeine 1.1 1.1 1.1 1.1 Panthenol 0.92 0.92 0.92 0.92 Sodium chloride 1 1 1 1 Phenoxyethanol 0.7 0.7 0.7 0.7 Cocoglucoside 0.5 0.5 0.5 0.5 Glyceryl oleate 0.5 0.5 0.5 0.5 Phosphoric acid 0.4 0.4 0.4 0.4 PEG-120 methyl glucose dioleate 0.3 0.3 0.3 0.3 HC Blue 2 0.22 0.22 0.22 Menthol 0.2 0.2 0.2 0.2 Polyquaternium-7 0.2 0.2 0.2 0.2 Sodium hydroxide 0.15 0.15 0.15 0.15 Dihydroxyindole 0.2 0.2 0.2 - Niacinamide 0.1 0.1 0.1 0.1 Zinc PCA 0.1 0.1 0.1 0.1 Dye/colorant 0.1 Citric acid 0.06 0.06 0.06 0.06

Neutral Formulation

[0132] The neutral formulation contains neither caffeine nor DHI nor HC Blue 2.

TABLE-US-00009 Component Quantity in % by weight Aqua [water] ad 100 Sodium lauryl ether sulfate 10 Laureth-2 1.9 Disodium lauryl sulfosuccinate 1.5 Sodium chloride 1.3 Sodium lauroyl glutamate 1.3 Panthenol 1.2 PEG-120 methyl glucose dioleate 0.5 Wheat protein hydrolyzate 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/colorant 0.0005

Application Examples

[0133] To evaluate the color performance in terms of quality, intensity and duration, the following washing tests (wash-on and wash-out tests) were carried out.

Application Example 1

[0134] Kerling strands were subjected to a wash-on test with a shampoo containing 5,6-DHI, caffeine and HC Blue 2 (Example Formulation 2) and with a shampoo containing HC Blue 2 and caffeine (Comparative Formulation), respectively, in order to examine the color performance in terms of quality and intensity.

Washing Protocol:

[0135] Moisten strands with lukewarm water for 30 seconds, brush out excess water between two fingers [0136] Massage in a total of 5 g shampoo for 1 minute per 5 strands [0137] Leave for a total of 5 minutes [0138] Rinse with lukewarm water for 1 minute, then squeeze out in kitchen roll [0139] Combing, spread out individually to air dry [0140] The next day, scan strands with the Konica (Konica-Minolta Spectrophotometer CM600d, measuring geometry d/8, Specular Component Excluded (SCE), standard illuminant D65, visual field) 10 (photograph sample strands every 5 washes); then repeat washing cycle

Used Hair Strands:

[0141] Kerling white selected, adhesive braid 2 cm wide, 12 cm long, 3 g/pc

Used Shampoos:

TABLE-US-00010 Example Formulation 2 Strands D1-D5 Comparative Formulation Strands E1-E5

[0142] For each product, 5 strands were used and 28 washes were carried out.

[0143] FIG. 1 shows a comparison of the strands D1/D2 treated with Example Formulation 2 with strands E1/E2 which were treated with the Comparative Formulation.

[0144] The comparison of the color preview for the two shampoos used is shown in FIG. 2. FIGS. 3 and 4 show the change in color depth as absolute values dL* (FIG. 3) and as total color change dE* (FIG. 4). The figures show the gradual build-up of the color effect with repeated use and the improved coloring result compared to the Comparative Formulation.

Application Example 2

[0145] Kerling strands were subjected to a wash-on and wash-out test with a shampoo containing 5,6-DHI, caffeine and HC Blue 2 (Example Formulation 2) and with a shampoo containing HC Blue 2 and caffeine (Comparative Formulation), respectively, in order to examine the color performance in terms of quality, intensity and duration.

Washing Protocol:

[0146] Moisten strands with lukewarm water for 30 seconds, brush out excess water between two fingers [0147] Massage in a total of 5 g shampoo for 1 minute per 5 strands [0148] Leave for a total of 5 minutes [0149] Rinse with lukewarm water for 1 minute, then squeeze out in kitchen roll [0150] Combing, spread out individually to air dry [0151] The next day, scan strands with the Konica (Konica-Minolta Spectrophotometer CM600d, measuring geometry d/8, Specular Component Excluded (SCE), standard illuminant D65, visual field) 10, photograph; then repeat washing cycle

Used Hair Strands:

[0152] Kerling white selected, adhesive braid 2 cm wide, 12 cm long

Used Color Shampoos:

TABLE-US-00011 Example Formulation 2 Strands B1-B15 Comparative Formulation Strands C1-C15

[0153] The neutral formulation was used for washing out.

[0154] For each product, 15 strands were treated in portions of 5 pieces.

[0155] The color change was monitored throughout the subsequent wash-on and wash-out cycles: [0156] 5 washes each with color shampoo to wash on, followed by 14 washes with neutral formulation (FIG. 5) [0157] 10 washes each with color shampoo to wash on, followed by 15 washes with neutral formulation (FIG. 6) [0158] 15 washes each with color shampoo to wash on, followed by 15 washes with neutral formulation (FIG. 7).

[0159] FIGS. 5-7 each show the change in color depth when washing on with color shampoo or washing out with neutral formulation according to the protocols given above. FIG. 8 shows the comparison of the color change for the two shampoos used on a single strand each at 15 wash-on cycles, followed by 15 wash-out cycles, measured with the Konica measuring device (Konica-Minolta Spectrophotometer CM600d, measuring geometry d/8, Specular Component Excluded (SCE), standard illuminant D65, visual field) 10. The figures show the gradual build-up of the color effect with repeated application and the improved staining result compared to the Comparative Formulation. After discontinuing the treatment with the shampoo according to the invention, the color effect also lasts longer than when using the Comparative Formulation.

Application Example 3

[0160] White Virgin strands (Imhair company) were subjected to a wash-on test with a shampoo containing 5,6-DHI and caffeine (Example Formulation 1) and with a shampoo containing 5,6-DHI, caffeine and HC Blue 2 (Example Formulation 2), respectively, and with a shampoo containing HC Blue 2 and caffeine (Comparative Formulation), respectively, in order to examine the color performance in terms of quality and intensity.

Washing Protocol:

[0161] Moisten strands with lukewarm water for 30 seconds, brush out excess water between two fingers [0162] Massage in a total of 2 g shampoo for 30 seconds per 3 strands [0163] Leave for a total of 5 minutes [0164] Rinse with lukewarm water for 1 minute [0165] Combing, air drying [0166] The next day, scan strands with the Konica, photograph; then repeat washing cycle

Used Hair Strands:

[0167] White Virgin (Imhair company)

Used Shampoos:

TABLE-US-00012 Example Formulation 1 Strands 1-3 Example Formulation 2 Strands 4-6 Comparative Formulation Strands 7-9

[0168] For each product, 3 strands each were used and 15 washing cycles each were carried out.

[0169] The comparison of the color preview for the shampoos used is shown for a single strand of hair in FIG. 9. FIGS. 10 and 11 show the change in color depth as absolute values dL* (FIG. 10) and as total color change dE* (FIG. 11). The figures show the gradual build-up of the color effect with repeated application and the improved dyeing result compared to the Comparative Formulation.

Application Example 4

[0170] To examine the dyed shade over time, the Kerling white and Imhair bleached strands were dyed for 15 min with 10 g of Example Formulation 2, rinsed for 1 min and air-dried for 1.5 h (residual moisture was then blow-dried). Measurements were taken on the day of treatment after 15 min exposure time (initial shade) and after 1, 2, 3, 8, 9, 10, 11, 14 and 15 days.

TABLE-US-00013 L*(D65) a*(D65) b*(D65) dL*(D65) da*(D65) db*(D65) dE*ab(D65) Kerling strand, white 76.58 2.15 21 Initial shade 62.32 1.58 5.02 14.27 0.57 15.98 21.43 (after 15 min exposure time) read in after 1 d 62.11 2.05 5.23 14.48 0.1 15.77 21.41 read in after 2 d 63.06 2.22 4.59 13.52 0.07 16.42 21.27 read in after 3 d 63.02 2.44 5.09 13.56 0.29 15.91 20.91 read in after 8 d 62.95 2.53 5.57 13.64 0.38 15.44 20.6 read in after 9 d 62.86 2.35 5.5 13.73 0.21 15.51 20.71 read in after 10 d 62.63 2.57 5.87 13.95 0.42 15.13 20.58 read in after 11 d 62.59 2.61 5.47 14 0.46 15.53 20.91 read in after 14 d 63.16 3.1 6.34 13.43 0.95 14.67 19.91 read in after 15 d 63.59 3.16 6.26 12.99 1.02 14.74 19.68

TABLE-US-00014 L*(D65) a*(D65) b*(D65) dL*(D65) da*(D65) db*(D65) dE*ab(D65) Imhair strand, 76.9 3.5 24.61 bleached Initial shade 51.51 1.01 2.73 25.38 2.49 21.88 33.61 (after 15 min exposure time) read in after 1 d 51.71 1.6 2.8 25.19 1.9 21.82 33.38 read in after 2 d 52.11 1.61 2.79 24.78 1.89 21.82 33.08 read in after 3 d 51.57 2.06 3.23 25.33 1.43 21.38 33.17 read in after 8 d 52.21 2.22 3.78 24.68 1.28 20.84 32.33 read in after 9 d 51.98 2.13 3.84 24.92 1.36 20.78 32.47 read in after 10 d 52 2.29 4.16 24.9 1.21 20.46 32.24 read in after 11 d 52.11 2.29 4.16 24.79 1.21 20.46 32.16 read in after 14 d 52.69 2.65 4.86 24.21 0.84 19.75 31.25 read in after 15 d 53.23 2.68 5.01 23.67 0.82 19.61 30.74

[0171] The measured values show aalso visually perceptibleshift in shade from the original graphite to a more natural, more brownish color.

Application Example 5

[0172] Kerling strands were subjected to a wash-on test with a shampoo containing 5,6-DHI and caffeine (Example Formulation 6) and with a shampoo containing 5,6-DHI, caffeine and HC Blue 2 (Example Formulation 7), respectively, and with a shampoo containing HC Blue 2 and caffeine (Example Formulation 8), respectively, in order to examine the color performance in terms of quality and intensity.

Washing Protocol:

[0173] Moisten 5 strands with lukewarm water for 30 s, squeeze out excess water between two fingers [0174] Massage in a total of 5 g shampoo for 1 min per 5 strands [0175] Leave for a total of 5 minutes [0176] Rinse with lukewarm water for 1 minute, then squeeze out with kitchen roll [0177] Comb, spread out individually to air dry [0178] The next day, scan strands with the Konica (Konica-Minolta Spectrophotometer CM600d, measuring geometry d/8, Specular Component Excluded (SCE), standard illuminant D65, visual field) 10, photograph; then repeat washing cycle

Used Hair Strands:

[0179] Kerling white selected, adhesive braid 2 cm wide, 12 cm long, 3 g/pc,

Used Coloring Shampoos:

TABLE-US-00015 Example Formulation 6 strands DHI-A to E Example Formulation 7 strands Combi-A to E Example Formulation 8 strands Blue-A to E

[0180] 5 strands were used per product, 15 washes were carried out in each case.

[0181] The comparison of the color preview for the shampoos used is shown for a single strand of hair in FIG. 12.

[0182] FIGS. 13 and 14 show the change in color depth as absolute values dL* (FIG. 13) and as total color change dE* (FIG. 14).

[0183] In FIGS. 12-14, the term DHI only refers to tests with a shampoo containing 5,6-DHI and caffeine (Example Formulation 6), the term DHI/Blue 2 refers to tests with a shampoo containing 5,6-DHI, caffeine and HC Blue 2 (Example Formulation 7) and the designation Blue 2 only refers to tests with a shampoo containing HC Blue 2 and caffeine (Example Formulation 8).

[0184] FIG. 15 shows a comparison of the strands washed with Example Formulation 6 (DHI-B), with Example Formulation 7 (Combi-B) and with Example Formulation 8 (Blue-B) using strand B as an example.

[0185] The figures show the gradual build-up of the color effect with repeated application and the improved coloring result compared to a Comparative Formulation only containing HC Blue 2 and caffeine (Example Formulation 8).