AU612706B2 - Pharmaceutical and/or cosmetic composition with controlling action on cutaneous pigmentation - Google Patents

Description

i S F Ref: 74172 FORM COMMONWEALTH OF AUSTRA 12 PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

706 FOR OFFICE USE: Class Int Class Complete Specification Lodged: Accepted: Published: Priority: ,Related Art: 0 a 4 Name and Address of Applicant: 4 0

D

Daniel Jean Rue de la Chaussade 63270 Vic-Le-Comte

FRANCE

L-eon -Can e-4 1EC- T I vS- Aif, J rue Raynouard Cic ri'c 'rpe^C, 7-5016 Paris

-FRANCE

Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Address for Service: Complete Specification for the invention entitled: Pharmaceutical and/or Cosmetic Composition with Controlling Action on Cutaneous Pigmentation The following statement is d full description of this invention, including the best method of performing it known to me/us 5845/3 Ii. c.

ABSTRACT

The present invention relates to a pharmaceutical and/or cosmetic composition with controlling action on cutaneous pigmentation, characterized in that it comprises, as an active substance, a chemical compound which has an inhibiting action on peroxydase and on tyrosinase.

This composition is available in the forms of lotion, milk, stick, mask, gel or cream.

44 4 4 4 0 1 I 4 4 t SBR/TGK/1598P -1

A.

3 The present invention relates to a pharmaceutical and/or cosmetic composition with controlling action on cutaneous pigmentation.

The mechanism of formation of the pigment responsible for skin coloration, melanin, is a complex oxidation mechanism which corresponds, very approximately, to the following scheme: Tyrosine -4 Dopa Dopachrome melanin.

This series of highly complex reactions is subject to the action of tyrosinase, which catalyses the oxidation of the various substrates. It is quite possible to carry out a biosynthesis of natural melanin "in vitro", starting from tyrosine and tyrosinase. However, these oxidations require a major input of oxygen, whose transfer can be efficiently provided by a peroxidase which will degrade the peroxides found in the dermis during the respiratory oxidative processes.

c Naturally coloured skins, white skins and those which have been o. 5 subjected to the action of ultraviolet radiations, sometimes exhibit nonuniform brown patches. These patches may be due to senescence, to an o abnormal effect of solar radiations, to pregnancy, to the use of oral contraceptives, to the use of ill-tolerated sunscreen products, to contact with plants or to plant extracts containing psorlenes or other photosensitizing substances.

These abnormalities of skin pigmentation appear to be due to a 0 0 S disorderly distribution of the oxygen available for the steps of oxidation of tyrosine to melanin.

The objective of the present invention is to overcome the abovementioned disadvantages by providing a pharmaceutical and/or cosmetic composition with controlling action on skin pigmentation, characterized in that it comprises, as an active substance, at least one chemical compound having an inhibiting action on peroxidase and on tyrosinase.

According to a broad form of this invention there is provided a method of regulating cutaneous pigmentation patches, comprising the topical application of a composition comprising a compound inhibiting peroxidase and tyrosinase, said compound conmprising gallic acid or an ester thereof.

A number of chemical compounds have this inhibiting action on peroxidase and on tyrosinase, particularly gallic acid and pyrogallol.

Nithin the scope of the invention, it is preferred to employ a composition for external topical use which is guaranteed to be completely harmless. A KEH/+7f 1 1_11~ 3A composition which comprises, as an active substance, gallic acid or one of its esters, especially with C 3 Cg9 alcohols, has these characteristics.

According to a characteristic of the invention, the said pharmaceutical and/or cosmetic composition contains approximately 0.2°/o to approximately 2.5% by weight of gallic acid or of its esters.

0 0 00 0 r, 4 o a 0 a I KE/179f M The composition according to the invention additionally comprises substances which can be used for its galenic embodiment, as well as, optionally, an agent promoting the entry of the active compound into the skin.

The composition according to the invention is suitable for naturally coloured skins, white skins and for tnose which have been subjected to the action of' ultraviolet radiations.

Esters of gallic acid especially the methyl, butyl or lauryl ester, for example, have the advantage of an improved stability when compared with gallic acid itself, particularly the butyl ester which, while having good stability, retains a certain solubility in water and has pharmacological properties akin to the free acid.

It is possible, of course, to employ other derivatives of the acid group or esters other than those described above to improve the properties of the compositions. Other characteristics and advantages of the present S' invention will become apparent from reading the description which is to follow.

In a first stage, an attempt has been made to evaluate the inhibiting effect of various substances on tyrosinase. The operating procedure is described in the example which follows: EXAMPLE 1: The tyrosinase employed has been extracted from carpophores of fresh Psalliota bispora with a pH 6.8 phosphate buffer.

The determination of tyrosinase activity is carried out by measuring the D.O. of the following solution at 475 nm at 250C: pH 6.8 buffer 0.5 ml DOPA at a concentration of 0.1% in pH 6.8 buffer. 1 ml Enzyme solution to be determined I ml The evaluation of the activity of an inhibitor is carried out by dissolving the substance to be tested in the buffer at a concentration of 0.02% (0.1 mg in 0.5 ml of buffer).

The measurements are carried out relative to a control solution not containing the substance to be tested.

A number of compounds have been tested, in particular hydroquinone and vitamin C, two commercial substances which are known to have an effect on pigmentation. Table I which follows, illustrates the results obtained.

SBR/TGK/1598P TABLE I SUBSTANCE TESTED INHIBITING POWER Hydroquinone Vitamin C Kojic acid 88 Caffeic acid 32 Gallic acid Pyrogallol 45.1 3-Hydroxy-2-methyl-4-pyrone 0 Azelaic acid 3 otr: 1 r; r Inhibiting power DO tested solution x 100 DO control solution It is found that the two commercial products do not appear among the most active substances, Vitamin C even being capable of activating pyrosinase.

In the second stage, the inhibiting effect of certain substances on peroxidase has been evaluated.

EXAMPLE II The peroxidase employed has been extracted from fresh roots of Cochlearia armoracia with the pH 6.8 buffer.

;The determination of the peroxidase activity is carried out by measuring the change in the D.O. at 485 nm of the following solution: pH 6.8 buffer 1.5 ml 10 vol. hydrogen peroxide 0.1 ml 0.1 ml of a 1% strength solution of p-phenylenediamine in the pH 6.8 buffer 0.1 ml Enzyme solution to be determined 0.4 ml The evaluation of the inhibiting power of a substance is measured by dissolving this substance in the buffer at the concentration of 0.005% g in 1.5 ml of buffer).

The compounds employed in Example I have been tested again.

SBR/TGK/1598P TABLE II SUBSTANCE TESTED INHIBITING POWER Hydroquinone 36.5 Vitamin C Kojic acid 20.5 Caffeic acid 43.5 Gallic acid 51 Pyrogallol 83 3-Hydroxy-2-methyl-4-pyrone Azelaic acid 4 From reading the two preceding tables, it appears that pyrogallol and gallic acid have a strong inhibiting effect, both on tyrosinase and on peroxydase.

However, pyrogallol is a product which is not tolerated well by skin.

Consequently, it has been withdrawn from this study.

EXAMPLE III Clinical study of gallic acid as a regulator of cutaneous pigmentation.

women aged between 18 and 45 and exhibiting a persistent chloasma are selected (Chloasma is a group of facial patches. It occurs on the face of the pregnant woman and constitutes the mask of pregnancy) from more than two years following a pregnancy or during a continual use of oral contraceptives.

people aged between 24 and 55, 7 men and 8 women, exhibiting facial patches following the use of sunscreen products are also selected.

I t Finally 20 people aged between 45 and 78, 10 men and ten women exhibiting hypermelanic patches on the hands are selected.

In all cases, a part of the affected region is treated with a placebo solution and an equivalent adjoining part, clearly defined in the photographs, is treated with a 0.5% strength solution of gallic acid in alcohol, for external topical use.

The treatment takes place twice daily, morning and evening in the case of the test and of the placebo, and is carried out for one month.

The assessment of efficiency is determined by a reflectometric method consisting in measuring the light reflected by the hyperpigmented skin, healthy skin of the same subject being taken as reference, This measurement involves the plot of the reflected light spectrum from 400 to 800 nm, which allows a simple erythema to be differentiated SBR/TGK/1598P from a true hyperpigmentation.

A plot of three curves is thus obtained: one for the healthy skin, one for the hyperpigmented skin, and one for the relative intensity of the two curves.

One measurement is carried out at the beginning of-the experimental period, one after one month's treatment and a last one after three month's treatment.

Resul ts In almost all cases, a very marked improvement is obtained in the first month.

Chloasma: A complete disappearance of the pigmentation disorder is observed in 44 cases out of 50, that is in 88% of cases.

A slight improvement is observed in two cases and no result at all in 4 cases.

Patches due to the use of sunscreen products A complete disappearance of the patches is observed in 11 cases out 0 0 of 15, that is in 73% of the cases.

An appreciable improvement is observed in one case and no improvement at all in 3 cases.

Senescence patches An appreciable improvement in the patches is observed in 12 cases out 0 t0 of 20, that is in 60% of the cases.

A slight improvement is observed in 3 cases arid no improvement at all in 5 cases.

No complete disappearance of the patches is observed.

No intolerance or discomfort due to the treatment is observed in any of the cases investigated.

Gallic acid is suitable for the preparation of different galenic compositions. These compositions are employed according to conventional methods. The following example illustrates a few of these.

EXAMPLE 4: Lotion formultion by weight) Glycerol 8 to 12 Gallic 0.2 to 0.8 0.05 to 0.15 Mater, perfume, preservatives.........remainder to 100%.

Gel formulation by weight) Crosslinked polyacrylic 0.5 to 1 SBR/TGK/l 598P Gallic acid 0.2 to 0.8 NaOH 0.1 to 0.3 Water, perfume, preservatives remainder to 100% Cream formulation by weight) Glycerol stearate 12 to 18 Polyoxyethylene glycol cetostearate 2 to 4 i Di-n-butyl adipate 8 to 12 Paraffin oil 2 to 4 I! Glycerol 4 to Gallic acid 0.5 to NaOH 0.1 to 0.3 ii Water, perfume, preservatives remainder to 100%.

i Milk formulation by weight) Mixture of palmitostearic acid mono- and diglycerides 5 to 7 Cetosteryl alcohol ethoxylated with 12 Smolecules of ethylene oxide 1 to 2 i Cetostearyl alcohol ethoxylated with j molecules of ethylene oxide 1 to 2 I 2-Octyldodecanol 8 to 12 1 Triglyceride of capric and caprylic acid 4 to 6 i Viscous paraffin oil 4 to 6 Gallic acid 0.2 to 0.8 I Water, perfume, preservatives remainder to 100%.

i Lotion formulation based on gallic acid at a high concentration(% by weight) Monopropylene glycol 8 to 12 Gallic acid 1.5 to Fatty acid polyol ester 4 to 6 Water, perfume, preservatives remainder to 100%.

j Mask formulation by weight) SSodium alginates 1.5 to 96% ethyl alcohol 8 to 12 Rice starch 27 to 33 Zinc oxide 2 to 4 Gallic acid 0.8 to 1.3 Water, perfume, preservatives remainder to 100%.

Stick formulation by weight) Cetostearyl alcohol 2 to 4 2-Octyldodecanol 40 to 46 SBR/TGK/1598P

F'

It 1~ It

II

ii Ii 1

I

ii If

II

II

ii Monoethanolamide of coprah fatty acids Palmitostearic acid Viscous paraffin oil 96% ethyl alcohol Gallic acid 2 to 4 9 to 9.6 2.2 to 37.7 to 38.5 0.2 to 0.8 SPR/TGK/1598P

Claims (14)

1. A method of regulating cutaneous pigmentation patches,)comprising the topical application of a composition comprising a compound inhibiting peroxidase and tyrosinase, said compound comprising gallic acid or an ester thereof.

2. A method as claimed in Claim 1 wherein the cLaneous pigmentation patches are chloasma patches, patches due to the use of sunscreen products ahd/or senescence patches.

3. A method as claimed in Claim 1 o- Clnim 2 characterised in that the compound is a C 3 -C 9 ester of gallic acid.

4. A method as claimed in Claim 3 characterised in that the compound is butyl gallate.

5. A method as claimed in any one of Claims 1 to 4, characterised in that thecomposition comprises 0.2 to 2.5% by weight of the compound.

6. A method*as claimed in any one of Claims 1 to 5, characterised in that the composition is in the form of lotion, milk, stick, mask, gel or cream.

7. A method as claimed in any one of Claims 1 to 6, characterised in that the composition corresponds to the following formulation (percentages by weight): 3 0-7,-to 3 0 3r; 3i 3 770I 3 7) 3 3 0440 000 0044 o 3~ 0 03 0 3 04Q 04 40 Glycerol 8 to 12% Gallic acid or ester 0.2 to 0.8% NaOH 0.05 to 0.15% Water, perfume, preservatives remainder to 100% 0

8. A method as claimed in any one of Claims 1 to 6, characterised in that the composition corresponds to the following formulation (percentages by weight): Glycerol stearate 12 to 18% Polyoxyethylene glycol cetostearate 2 to 4% Di-n-butyl adipate 8 to 12% Paraffin oil 2 to 4% Glycerol 4 to 5% Gallic acid or ester 0.5 to 1.5% NaO11 0.1 to 0.3% Water, perfume, preservatives remainder to 100%

9. A method as claimed in any one of Claims 1 to 6, characterised in that the composition corresp6nds to the following formulation (percentages by weight): Mixt Ceto ethy Ceto ethy 2-Oc Trig Viisc Gall Wate

10. A me the compc weight): Monof Gall. FattN Wate

11. IA mel the compo weight): SodiL 96% E Rice Zinc Galli Watel

12. A met the compo weight): Cetos 2-Oct Monoe Palmi visco 96% e Galli

13. A pha cutaneous reference 0000 0t o 0 0 30 4 00 4 4 01 04 0 4 0 y\4W SII A4Y 11 Mixture of palmitosteatic acid mono- and diglycerides 5 to 7% Cetostearyl alcohol ethoxylated with 12 molecules of ethylene oxide 1 to 2% Cetostearyl alcohol ethoxylated with 20 molecules of ethylene oxide 1 to 2% 2-Octyldodecanol 8 to 12% Triglyceride of capric and caprylic acids 4 to 6% Viscous paraffin oil 4 to 6% Gallic acid or ester 0.2 to 0.8% Water, perfume, preservatives remainder to 100% A method as claimed in any one of Claims 1 to 6, characterised in that the composition corresponds to the following formulation (percentages by weight): Monopropylene glycol 8 to 12% oo, Gallic acid or ester 1.5 to o Fatty acid polyol ister 4 to 6% oo 0 Water, perfume, preservatives remainder to 100% S 11. A method as claimed-in any one of Claims 1 to 6, characterised in that S the composition corresponds to the following formulation (percentages by weight): Sodium alginates 15 to 96% ethyl alcohol 8 to 12% SRice starch 27 to 33% o Zinc oxide 2 to 4% Gallic acid or ester 0.8 to 1.3% Water, perfume, preservatives remainder to 100% 12. A method as claimed in any one of Claims 1 to 6, characterised in that the composition corresponds to the following formulation (percentages by S' weight): Cetostearylic alcohol 2 to 4% 2-Octyldodecanol 40 to 46% Monoethanolamide of coprah fatty acids 2 to 4% Palmitostearic acid 9 to 9.6% Viscous paraffin oil 2.2 to 96% ethyl alcohol 37.7 to 38.5% Gallic acid or ester 0.2 to 0.8% 13. A pharmaceutical and/or cosmetic composition with controllinglaction oo cutaneous pigmenlation I substantially as hereinbefore described with reference to Example 4. MS 12

14. A method of regulating cutaneous pigmentation patches in a human requiring such regulation, which method comprises applying topically to said human a composition as claimed in claim 13 in an amount which ecfectively regulates said cutaneous pigmentation patches. DATED this SIXTEENTH day of APRIL 1991 Daniel Jean, Reckitt Colman pCI? PPOJ no(ir) iO ill 01 ii C1 3 i) 1 Patent Attorneys for the Applicant SPRUSON FERGUSON a o 0 I KEH179f