GB2050829A

GB2050829A - Cosmetic agent comprising a pH colour indicator

Info

Publication number: GB2050829A
Application number: GB8015820A
Authority: GB
Original assignee: Dr Babor GmbH and Co
Current assignee: Dr Babor GmbH and Co
Priority date: 1979-05-15
Filing date: 1980-05-13
Publication date: 1981-01-14
Also published as: DE2919422A1; FR2456518A1; DE2919422C3; DE2919422B2; GB2050829B

Abstract

A cosmetic agent for treating the skin comprises an acidimetric colour indicator with a transition range from pH 1.2 to 13.0 in addition to customary active cosmetic substances, moisturisers and/or cosmetic adjuvants. Preparations are applied one after the other onto the skin; the mixture of preparations is removed when the indicator changes colour.

Description

SPECIFICATION Cosmetic agent and method for treating the skin with a cosmetic agent This invention relates to cosmetic agents and methods of skin treatment.

As a consequence of its acidic coating the skin has its own optimal pH value of about 5 to 6. It is a known fact that successful cosmetic treatment of the skin and its structures is dependent mainly on the active hydrogen ion concentration (pH value) of the cosmetic agents being used. Use is not infrequently made of preparations which are strongly alkaline or strongly acidic, whose pH values are accordingly far removed from the optimal physiological pH value of the skin. At the conclusion of a cosmetic treatment process the skin's acidic coating should always be restored (regenerated). To effect this pH regeneration, hitherto the specifically effective preparation was generally washed off and then, if the preparation was strongly alkaline as in the case of a depilation cream, an acidic cream or tonic was applied to the skin.

In order to limit the necessary effect of strongly alkaline or strongly acidic agents on the skin to the required extent, and to restore the natural physiological conditions of the skin as soon as possible, it would be extremely useful if the course of a cosmetic treatment process could easily be observed, checked and regulated. This applies in particular for the conclusion of the course of treatment, namely regeneration of the pH in order to restore the physiological pH value of the skin.

We have also sought to provide a cosmetic agent where as large a proportion as possible of the active substances and skin-care components contained in the cosmetic agent is taken up into or deposited on the skin in a treatment time which is as short as possible and which can be exactly measured.

The invention provides a cosmetic process for treating the skin and its structures, which comprises applying a cosmetic agent that contains one or more acidimetric colour indicators and that allows the course of treatment to be regulated by means of the discernible colour change. According to the invention, the pH of the skin is regenerated following the application of strongly alkaline preparations, especially cold wave agents, depilatories or skin-softening masks, by removing the strongly alkaline preparations with cosmetic agents which contain acidimetric colour indicators with a transition range from pH 1.2 to 13.0; the treatment is concluded when the colour changes.

A similar method is employed for the pH regeneration of the skin following the application of strongly acidic preparations, especially bleaching agents for hair and skin. In this case too, according to the invention, the strongly acidic preparations are removed with cosmetic agents that have acidimetric colour indicators with a transition range from pH 1.2 to 13.0, the treatment being concluded when the colour changes.

The invention also provides an acidic or alkaline-adjusted pH regeneration agent for application to the skin and containing acidimetric colour indicators with a transition range between pH 1.2 and 13.0, in particular pH 2 to 9 and preferably pH 4 to 8.

Through the use of the cosmetic agents according to the invention a simple, visible check on the regeneration of the physiological pH value of the skin is ensured which has hitherto not been possible with the use of cosmetic agents.

The easy and safe check on the pH value during a cosmetic treatment with the help of pH indicators makes it possible to develop cosmetic agents from two or more preparations with different pH values and independent of each other as regards their use, of which at least one contains an acidimetric colour indicator.

These cosmetic agents are also subject of the invention. With their help, a guaranteed effective treatment with active substances aimed at a particular result is possible. In this way, the active substances can be controllably applied in the highly active nascent state. In addition, it is possible to obtain a hitherto unknown concentration of active substances in the skin. The "depot effect" which can thus be achieved signifies a considerable advance in cosmetic treatments.A cosmetic agent of this sort, according to the invention, consists for example of a preparation A containing the active substances and having a pH value which deviates strongly from the pH value of the skin, and a preparation B containing a pH regeneration agent for the skin; at least one of these preparations contains the acidimetric colour indicator with a transition range from pH 1.2 to 13.0, in particular pH 2 to 9 and preferably pH 4to 8. Preparation A can be strongly alkaline with a pH of about 12 to 8, especially 11 to 8, or strongly acidic with a pH of about 1.5 to 4, especially 2 to 3, according to the desired method of cosmetic treatment.

Cosmetic agents according to the invention can also consist of a strongly alkaline preparation A containing an acidimetric colour indicator, a strongly acidic preparation B and a preparation C containing a pH regeneration agent of pH about 5.0 to 6.0 for the skin and an acidimetric colour indicator with a transition rangefrom pH 1.2 to 13.0, in particularpH2to9and preferablypH4to 8. As the pH regeneration agent a buffer system is preferably used, for example, acetic acid/sodium acetate, boric acid/sodium borate, phosphoric acid/sodium phosphate or sodium bicarbonate/sodium carbonate.

The advantageous effects of such two-phase or three-phase preparations are elucidated by means of the examples. Treating the skin with an alkaline preparation A. causes swelling of the uppermost dermal layer and first makes possible, or at least considerably improves, the penetration into the skin of special active substances such as, for example, allantoin, tocopherol, lecithin, moisturising agents, collagen or uracil.

Following the necessary duration of action, the acidic preparation B is applied and mixed carefully with preparation A on the skin by massaging. The acidic preparation hardens the swollen upper dermal layer and the skin is practically sealed again once the active substances have penetrated. The process of pH regeneration, and thus the end of the treatment, has been reached when the colour indicator changes colour.

The preparations are then removed from the skin by means of damp compresses.

A two-phase treatment with a cosmetic agent where preparation A is acidic is recommendable, for example, for an optimal active substance treatment with collagen. Preparation A needs to be acidic on account of the solubility of the collagen. When regenerating the pH with preparation B the collagen precipitates and remains in intensive contact with the skin, even when the masks are removed at the end of the treatment with damp compresses.

An "active substance depot" can be obtained in the skin by means of the action of several preparations with different pH values, as can be shown using the example of a uracil-depot mask treatment. Uracil is hardly water-soluble in the acidic pH range, slightly water-soluble in the pH range of the skin and easily water-soluble in the alkaline range. This is explained by the fact that uracil is a dibasic acid with different acid constants. In order to obtain an optimal uracil depot in the skin, the treatment is carried out with three preparations which are applied one after the other. The skin is softened by the alkaline preparation A and allows the active substances to penetrate. At this pH value of e.g. 10 the uracil is easily soluble and diffuses well into the skin.For this purpose preparation A is applied generously to the parts of the skin to be treated, distributed well by massaging and left there for 2 to 8, especially 2 to 5 minutes. Following the duration of action, the preparation B, for example, an acidic face tonic with pH 2 to 3 is applied and mixed intensively, by massage, with preparation A on the skin until the colour changes. In this way the uracil is transformed into its insoluble form and remains to a large extent in the skin when the uracil mask is removed with the acidic face tonic. To complete the treatment, a pH regeneration cream (preparation C) is then applied until its colour change shows that the skin's optimal pH value of about 5.5 has been reached.

The acidimetric colour indicators suitable for purposes of the invention are in fact known. They must, however, for the purposes of the invention, be sufficiently stable in their application with respect to the active substances and other components of the cosmetic agent, reliable, and furthermore must be tolerated by the skin. The indicators which according to present-day knowledge can be considered for use in cosmetic agents are listed in the following table together with the pH range for their colour reactions and their special colour changes.

No. Indicator pH Range Colour Change 1. Tropeolin0o 1.2-3.2 violet red (Cl. 13080) yellow orange 2. Benzyl orange 1.9 - 3.3 red - yellow 3. Benzopurpurin 4B (C.I. 23560) 2.3 - 4.4 blue violet - red 4. Congo red (C.l. 22120) 3.0 - 5.2 blue - red 5. Brom-phenolblue 3.0-4.6 yellow - blue violet 6. Bromchlorphenol blue 3.0-4.6 yellow-violet 7. Methyl orange 3.0 -4.4 red - yeliow orange (Cl. 13025) 3.5-5.7 violet pink- brownish yellow 8. a-Naphthylred 3.7-5.0 purple-yellow orange 9. Bromcresol green 3.8-5.4 yellow - blue 10. Methyl red (Cl. 13020) 4.4-6.2 red-yellow 11. Ethyl red 4.4 - 6.2 red - yellow 12. Chlorophenol red 4.6 -7.0 yellow - red violet 13. Carminicacid (C.1.75470) 4.8 - 6.2 yellow - red violet 14. Alizarin red S (C.l. 58005) 5.0 - 6.6 yellow - violet red No. Indicator pH Range Colour Change 15. Litmus 5.0 - 8.0 red - blue violet 16. Bromcresol purple 5.2-6.8 yellow-violet 17. Bromphenolred 5.4-7.0 yellow - purple 18. Alizarin (C.1.58000) 5.8 - 7.2 yellow - red violet 19. Bromothymol blue 6.0-7.5 yellow - blue 20. Bromxylenol blue 6.0 - 7.6 yellow - blue 21. Brasilin (C.l. 75280) 6.0 - 7.7 greenish yellow dark violet 22.Nitrazine yellow (C.l. 14890) 6.0 - 7.0 yellow - blue violet 23. Hematoxylin (C.l. 75290) 6.0 - 11.0 yellow - violet 24. Phenol red 6.4 - 8.2 yellow - red 25. Neutral red (C.l. 50040) 6.8 - 8.0 red - yellow 26. Cresol red 0.2-1.8 pink red - yellow 7.0 - 8.8 yellow - violet red 27. m-Cresol purple 1.2-2.8 red-yellow 7.4-9.0 yellow - violet 28.Brilliant yellow (C.l.24890) 7.4 - 8.6 yellow - brown red 29. α-Naphtholorange 7.6-8.9 yellow-pink 30. a -Naphtholphthalein 7.8 - 9.0 pale yellow - blue 31. Thymol blue 1.2-2.8 red - yellow 8.0-9.6 yellow - blue 32. Xylenolblue 1.2-2.8 red-yellow 8.0-9.6 yellow- blue 33. o-Cresolphthalein 8.2-9.8 colourless - red violet 34. Phenolphthalein 8.4- 10.0 colourless - purple 35. a -Naphtholbenzein 8.8-11.0 colourless - blue green 36. Thymolphthalein 9.3-10.5 colourless-blue 37. Water blue (C.1.42755) 9.4-14.0 Blue-(red) colourless 38. Alizarin orange GG (Cl. 14025) 10.0-12.0 pale yellow- orange yellow No.Indicator pH Range Colour Change 39. Alizarin orange R (C.l. 14030) 10.0 - 12.0 pale yellow orange red 40. Nile blue A 10.2-13.0 blue violet red 41. (3-Naphthol violet 10.6 - 12.0 orange yellow violet 42. Gold yellow (C.l. 14270) 11.1 - 12.7 yellow-brown red Of the above acidimetric colour indicators, those which are differently coloured in different pH ranges are particularly useful for cosmetic treatment. These are, e.g. methyl orange, (No. 7), cresol red (No. 26), m-cresol purple, (No. 27), thymol blue, (No. 31) and xylenol blue (No. 32).

The indicators can be used in special mixtures such that pH changes can be observed by means of a continuous, manifoldly graduated colour transition.

The invention is illustrated by the following Examples.

Example 1 Face tonic for pH regeneration of the skin following application of a depilation cream.

1-Propyl alcohol 10.0 parts by weight Perfume 0.1 Allantoin 0.2 Bromothymol blue 0.005 Eumulgin 0 10* 0.2 Phosphate buffer solution according to Sorensen** pH 5.5 made up to 100.0 * Emulsifying agent based on fatty alcohol or alkyl aryl polyglycol ethers ** Potassium biphosphate/disodium biphosphate solution The preparation is yellow. A compress or wad of cotton wool is dampened with the tonic and the skin is cleaned of depilation cream. For as long as the alkaline depilation cream is not completely neutralised, the compress or wad of cotton wool is turned to blue. A colour change from yellow to blue is no longer observed when the depilation cream has been neutralised, i.e. when the physiological pH value of the skin has been reached.

Example 2 Face tonic for pH regeneration of the skin following application of a skin bleaching agent.

In order to regenerate the pH a similar face tonic is used as in Example 1, except that the tonic of Example 2 contains the indicator bromcresol green. The face tonic is thus green. For as long as the acidic face mask is not completely neutralised and the pH value of the skin regenerated, the cotton wool or compress is coloured yellow.

Example 3 pH-Regeneration emulsion for the skin following treatment with an acidic face mask.

Di-ethanolamino cetyl phosphate (Amphisol) 3.0 parts by weight Stearic acid 3.0 Isopropyl myristate 5.0 Paraffin oil 5.0 Phosphate buffer solution according to Sorensen pH 5.5 9.5 Bromcresol green 0.01 Perfume 0.2 Distilled water made up to 100.0 This pH regeneration emulsion is blue and turns yellow for as long as the physiological pH value of the skin has not yet been reached. Application of the emulsion is analogous to that of the tonic according to the preceding Examples.

Example 4 Two-phase regeneration mask Preparation A: Ointment base* 10.50 parts by weight Squalane 6.00 Coconut oil 6.00 Distilled water 55.45 4-Hydroxybenzoic ester 0.35 1,2-propanediol 4.00 Complex of moisturising factors (Hygroplex)** 4.00 Litmus 0.20 Potassium carbonate 0.50 Allantoin 2.00 Tocopherol acetate 0.60 Powder mixture*** 10.00 Perfume 0.40 Preparation B: Bentonite 2.60 Glycerin 12.00 Citric acid 2.50 Distilled water 83.30 4-Hydroxybenzoic methyl and/or propyl ester 0.30 Sodium benzoate 0.20 Emulgin 0 10 2.00 Perfume 0.10 * Vaseline (Trade Mark), paraffin - polyethylene, triglycerides, carbohydrates, lipogel, bentonite, cellulose derivates and/or polyethylene glycol.

** Mono- and disaccharides, amino acids, urea and weak hyperemisation substances.

Talcum, corn starch, titanium dioxide and/or wheat starch.

The pH value of preparation A is about 10. Due to its litmus content it is blue, and is applied generously onto the parts of the skin to be treated, particularly face, décolleté etc. This mask is left on the skin for about 5 minutes. The colourless, acidic preparation B (pH value 2.8) is subsequently applied to the parts of the skin to be treated and mixed carefully with preparation A on the skin by means of massage. The treatment is concluded when the acidic coating of the skin has been restored, i.e. when the blue litmus colour of the combined masks has turned to red. The preparations are then removed from the skin with damp compresses.

Example 5 Two-phase collagen mask Preparation A: Aerosil (Trade Mark) 3.5 parts by weight Na-alginate 0.5 Titanium dioxide 2.0 Acidic solution of collagen (Collapur) 5.0 Methyl red 0.02 4-Hydroxybenzoic methyl ester 0.18 Distilled water made up to 100.0 Preparation B: Phosphate buffer according to Sörensen pH 6.5 made up to 100.0 Na-caraginate (Viscarine) 2.0 4Hydroxybenzoic 0.2 methyl ester Preparation A is acidic and is coloured red by the indicator methyl red. It is applied generously to the parts of the skin to be treated and distributed for about 3 minutes by massaging lightly. The colourless preparation B is subsequently applied on top of the red preparation A and the two masks mixed thoroughly on the skin until the red colour has turned completely to yellow.At the isoelectric point (pH 5 to 6) the collagen precipitates, the pH having been regenerated, and remains in contact with the skin even after the masks have been removed by treatment with damp compresses.

Example 6 Uracil-depot mask treatment Preparation A (Alkaline uracil mask): K-carbonate 0.2 parts by weight Uracil 0.2 1,2-propanediol 4.0 Hydroxybenzoic ester 0.2 Bentonite 3.0 n Bromcresol green 0.02 Distilled water made up to 100.0 Preparation B (Acidic face tonic): Na-alginate 0.2 parts by weight Citric acid 1.0 1,2-propanediol 5.0 Hydroxybenzoic ester 0.2 Distilled water made up to 100.0 Preparation C (pH-Regeneration uracil cream): Emulsion according to Example 3 with 0.1 parts by weight of uracil.

The blue preparation A, which contains the dissolved uracil, is applied generously to the parts of the skin to be treated, distributed well by massaging and left on for a further 3 to 5 minutes. After the duration of action the colourless, acidic face tonic (preparation B) with pH value 2.8 is applied and mixed intensively with mask A by massaging until the blue colour has turned completely to yellow. This causes the uracil to precipitate. Finally a pH regeneration cream C which contains uracil is applied, the uracil content of which increases the uracil depot which has already been worked into the skin and which is only slightly soluble in the pH range of the skin. The blue cream C, applied with a ball of cotton wool, is coloured yellow for as long as the optimal skin pH value of about 5.5 has not been reached.The preparation C may contain a further indicator, e.g. bromothymol blue, or may be used without an indicator.

Example 7 Two-phase regeneration mask Preparation A: Amorphous silicic acid (Aerosil) 9.000 parts by weight Corn starch 2.000 Allantoin 2.000 11 1,2 Dipropyl alcohol 6.000 Panthenol 1.200 4-Hydroxy benzoic methyl ester 0.0002 4-Hydroxy benzoic propyl ester 0.00006 Alizarin 0.00002 Triethanolamine 2.000 Extract of wheatgerm (Epigran) 4.000 Emulgin 010 0.0001 Tocopherol acetate 0.0006 Distilled H2O made up to 100.000 Preparation B: (Teginacid)* 5.000 (Emulgade F Spezial)** 4.000 Isopropyl myristate 5.000 Cetyl stearyl alcohol mixture 1.000 Mixture of triglycerides (Miglyol 812) 5.000 1,2-propane diol 4.000 Moisturising agent (Hygroplex)*** 4.000 4-Hydroxy benzoic methyl ester 0.0002 4-Hydroxy benzoic propyl ester 0.0001 Na-benzoate 0.0002 Lactic acid 2.000 Distilled H2O made up to 100.000 * o/w emulsifying agent of glycerin mono-distearates and polyglycol fatty alcohol ether ** Emulsifying agent based on cetyl stearyl alcohol with addition of cetyl stearyl sulphate - Na or non-ionic polyglycol ether Mono- and disaccharides, amino acids, urea and weak hyperemisation substances.

The pH value of preparation A, which is blue-violet in colour, is about 8.2. It is applied to the skin, where it is allowed to take effect for about 5 minutes. During this time the skin swells, which results in better or increased uptake of the active substances. Then the colourless, acidic preparation B with pH 2.6 is applied and mixed with the preparation A already on the skin until the colour turns to yellow. The mixture of preparations is then removed from the skin.

Claims

CLAIMS 1. A cosmetic agent for treating the skin, comprising at least one customary active cosmetic substance, at least one moisturiser and, or at least one cosmetic adjuvant, and containing at least one acidimetric colour indicator having a transition range from pH 1.2 to 13.0. 2. A cosmetic agent according to claim 1, comprising a preparation which contains at least one active skin substance and a strongly acidic or strongly alkaline agent, and at least one additional preparation which contains an agent for regenerating the pH value of the skin to the physiological pH value, the individual preparations being intended for application to the skin one after the other and being mixed with one another on the skin, and at least one of the preparations containing a colour indicator with a transition range from pH 1.2to 13.0. 3. A cosmetic agent according to claim 1, comprising a strongly alkaline preparation A which contains at least one active skin substance, at least one additional customary cream component and at least one acidimetric colour indicator with a transition range from pH 1.2 to 13.0, a second, strongly acidic preparation B to precipitate the active skin substance or substances, and a preparation C with a pH-regenerating agent for the skin and optionally an acidimetric colour indicator with a transition range from pH 1.2 to 13.0. 4. A cosmetic agent according to claim 1, comprising a preparation A with the following components: Amorphous silicicacid 9.0 parts by weight Corn starch 2.0 1 ,2-propanediol 6.0 4-Hydroxybenzoic methyl and propyl ester 0.0003 Panthenol 1.2 Alizarin 0.00002 Allantoin 2.0 Tri-ethanolamine 2.0 Emulsifying agent 0.0001 Extract of wheat germ 4.0 Tocopherol acetate 0.0006 Distilled water made up to 100.0 and a preparation B with the following components: ow Emulsifying agent 10.0 parts by weight Isopropyl myristate 5.0 Mixture of triglycerides 5.0 1,2-propanediol 4.0 Moisturising agent 4.0 Lactic acid 2.0 4-Hydroxybenzoic methyl and propyl ester 0.0003 Sodium benzoate 0.0002 Distilled water made up to 100.0 5.A cosmetic agent according to claim 1, substantially as hereinbefore described with reference to any of the Examples. 6. A method of treating the skin with a cosmetic agent according to any one of claims 1 to 5, which comprises first applying a strongly acidic or strongly alkaline preparation, containing at least one active skin substance and at least one additional customary cream component, to the skin and allowing it to take effect; then applying at least a second preparation, containing an agent for regenerating the pH value of the skin to the physiological pH value (pH = about 5 - 6); mixing the second preparation with the preparation initially applied, at least one of the preparations applied containing at least one colour indicator with a transition range from pH 1.2 to 13.0 and the preparations being mixed until the colour of the mixture changes; and then removing the mixture of preparations from the skin. 7. A method of treating the skin with a cosmetic agent, which comprises first applying a strongly acidic or strongly alkaline preparation, containing at least one active skin substance, at least one additional customary cream component and at least one colour indicator with a transition range from pH 1.2 to 13.0, to the skin and allowing it to take effect; then applying a second preparation, containing an agent for neutralising the pH value of the first preparation; mixing the second preparation with the preparation which was initially applied until the colour of the mixture changes; then applying a third preparation, containing an agent for regenerating the pH value of the skin to the physiological pH value, at least one colour indicator with a transition range from pH 1.2 to 13.0 and optionally at least one other active skin substance; mixing the third preparation with the mixed preparation until the colour changes; and then removing the mixture of preparations from the skin. 8. A method according to claim 6 or 7, wherein the acidimetric colour indicator has a transition range from about pH 2 to 9. 9. A method according to claim 8, wherein the transition range is from about pH 4 to 8. 10. A method according to any one of claims 6 to 9, wherein at least one of the preparations contains at least one skin active substance selected from allantoin, vitamin B, E or F, natural vitamin oils, lecithin, uracil and collagen. 11. A method according to any one of claims 6 to 10, wherein the strongly alkaline preparation has a pH value of about 12 to 8, and the strongly acidic preparation has a pH value of about 1.5 to 4. 12. A method according to claim 11, wherein the strongly alkaline preparation has a pH of 11 to 8 and the strongly acidic preparation has a pH of 2 to 3. 13. A method according to any one of claims 6 to 12, wherein the agent for regenerating the pH value of the skin contains a buffer substance with a pH of about 5.0 to 6.0 14. A method according to claim 13, wherein the buffer substance consists of acetic acid/sodium acetate, boric acid/sodium borate, phosphoric acid/sodium phosphate or Na-bicarbonate/Na-carbonate. 15. A method according to any one of claims 6 to 14, wherein the colour indicator is at least one of the following: No. Indicator

1. Tropeolin00 (C.l. 13080)

2. Benzyl orange

3. Benzopurpurin 4B (C.l. 23560)

4. Congo red (C.l. 22120)

5. Brom-phenol blue

6. Bromchlorphenol blue

7. Methyl orange (C.l. 13025)

8. a-Naphthyl red

9. Bromcresol green

10. Methyl red (C.l. 13020)

11. Ethyl red

12. Chlorophenol red

13. Carminicacid (C.l. 75470)

14. Alizarin red S (C.l. 58005)

15. Litmus

16. A method of treating the skin with a cosmetic agent, substantially as hereinbefore described with reference to any of the Examples.

16. Bromcresol purple

17. Bromphenol red

18. Alizarin (C.l. 58000) 19.Bromothymol blue

20. Bromxylenol blue

21. Brasilin (C.l. 75280)

22. Nitrazineyellow (C.1.14890)

23. Hematoxylin (C.l. 75290)

24. Phenol red

25. Neutral red (C.l. 50040)

26. Cresol red

27. m-Cresol purple

28. Brilliant yellow (C.l. 24890)

29. a-Naphtholorange

30. a-Naphtholphthalein

31. Thymol blue

32. Xylenol blue

33. o-Cresolphthalein

34. Phenolphthalein

35. a-Naphtholbenzein

36. Thymolphthalein

37. Water blue (C.l. 42755)

38. Alizarin orange GG (C.l. 14025)

39. Alizarin orange R (C.l. 14030)

40. Nile blue A

41. p-Naphthol violet 42. Gold yellow (C.l. 14270)