Bleaching and dyeing; fluid treatment and chemical modification – Dyeing involving animal-derived natural fiber material ,... – Hair dyeing
Reexamination Certificate
2002-03-05
2004-03-16
Gupta, Yogendra N. (Department: 1751)
Bleaching and dyeing; fluid treatment and chemical modification
Dyeing involving animal-derived natural fiber material ,...
Hair dyeing
C008S406000, C008S426000, C008S428000, C008S431000, C008S546000, C008S637100
Reexamination Certificate
active
06706077
ABSTRACT:
TECHNICAL FIELD
The present invention relates to compositions for changing the colour of keratinic fibers especially human hair. The composition can also be used to darken human skin.
BACKGROUND
Melanin is a naturally occurring pigment present in hair and skin and it is synthesised in melanocytes in the presence of the enzyme tyrosinase. Two different melanins are found in human hair, eumelanin and pheomelanin. While brown and black hair contain eumelanin, pheomelanin is found in red hair.
The enzyme tyrosinase catalyses the hydroxylation of tyrosine to 3,4-dihydroxyphenylalanine (DOPA) and its subsequent oxidation to dopachrome. Dopachrome further undergoes a series of complex reactions to form eumelanins and pheomelanins (often collectively termed melanin).
Efforts have been made in the past to provide a hair dyeing process that mirrors the formation of the hairs' natural pigment, melanin. These efforts relied in general upon treatment of hair with a recognized intermediate of the melanin pathway, most often tyrosine or DOPA or its analogs resulting in formation of melanin and consequent colouring of hair. An oxidative post-treatment is usually required to get satisfactory, fast colours.
DOPA is available naturally in nature. It can also be prepared synthetically and many hair compositions use the synthetic form that is available commercially. However, there have been some problems associated with the use of synthetic DOPA. Synthetic DOPA is reported to be unstable and to have a tendency to oxidise prematurely. Moreover, it can also be costly to synthesise. Further, there is a consumer preference for natural products as these are perceived to be safe.
An example of a natural source of DOPA is Mucuna, a genus belonging to the family Leguminosae with about 15 species, some of which can be found in India. Annual or perennial twining herbs or shrubs distributed in the tropics and subtropics, Mucuna includes many species like
Mucuna urens, Mucuna puriens
and
Mucuna sloanei.
While providing for a stable, natural form of DOPA to darken skin or hair is highly desirable, colour substantivity to the keratinic fibre and colour fastness is often difficult to achieve with natural materials.
PRIOR ART
Brown et al, J of Soc, of Cos. Chemists, 48, 1997, 133 relates to a process of converting DOPA on hair to 5,6-dihydroxyindole by careful selection of the oxidant. This indole is a precursor of black eumelanin and it is readily polymerised in situ to dye the hair black. Nucleophiles such as cysteine and other throls are added to produce a wide range of shades on hair.
U.S. Pat. No. 3,993,436 discloses a three component hair colouring system comprising of a cutting agent (for the cysteine bond in hair), tyrosine and/or synthetic DOPA or its derivatives and an oxidising agent. The cutting agent helps in better dyeing by making hair more susceptible to the uptake of organic molecules, like dyes.
EP0914816 discloses extracts from several plant sources, including Mykania Glomerata, Japanese pepper and Parameria laevigata that have superior tyrosinase promoting actions and prevent grey hair formation or darken grey hair.
U.S. Pat. No. 3,941,835 discloses the recovery of L-Dopa from several naturally occurring materials, including the seeds of
Mucuna puriens.
The prior art is therefore mainly concerned with the use of synthetic DOPA and its analogs or precursors for colouring skin and hair. As already mentioned, there may be problems associated with the use of synthetic DOPA. Natural materials that promote tyrosinase activity are known in the art, however these may not give as good a colouring as systems using DOPA.
The prior art does not therefore disclose a stable, natural source of DOPA to colour hair and skin. Also the prior art does not indicate how to achieve superior colouring and colour fastness using a natural product.
The applicants have now found that it is possible to obtain superior dark colour on hair and skin using a colouring system comprising the Mucuna plant or its extract, a cysteine cutting agent and an oxidising agent. The colour generated by this process is superior to the one generated using synthetic DOPA and it is possible to generate a wide range of shades by this process. Mucuna being cheap and readily available, the invention also provides for an inexpensive process to colour skin and/or hair. The product will be safe as the composition is based on a natural material.
SUMMARY OF THE INVENTION
Thus the present invention provides for a system for colouring hair and/or skin comprising at least three separately packaged components: a) a thio compound capable of cutting the cysteine bond and an alkaline reagent which may or may not be separately packaged b) Mucuna and c) an oxidising agent. The colouring system may be suitably supplied in the form of a combination kit. A method of dyeing skin and/or hair is also provided comprising the sequential steps of application of the thio compound and alkaline reagent followed by the application of Mucuna and finally applying the oxidising agent.
The term mucuna encompasses materials and extracts obtainable from the mucuna plant, including the dried powder of the plant or parts of the plant, the extract obtained by solvent extraction of mucuna or a wet homogenate in a suitable solvent. The term also encompasses solutions, dispersions and suspensions of the same.
The colouring system of the invention is based on a natural material, provides for a wide range of shades and is inexpensive and safe.
DEFINITION OF THE INVENTION
According to one aspect of the invention there is provided a colouring system for hair and/or skin comprising at least three separately packaged components:
a) a thio compound capable of breaking the S—S bond between cysteine residues, and an alkaline reagent;
b) a material and/or extract obtainable from the mucuna plant; and
c) an oxidising agent.
According to a preferred aspect of the invention there is provided a colouring system for hair and/or skin comprising at least three separately packaged components:
a. a thio compound capable of cutting the S—S cysteine bond, preferably in the form of a fluid composition having a concentration of from 0.01 to 8% weight/volume and an alkaline reagent, said alkaline reagent being supplied with the thio compound or as a separate package.
b. Mucuna or its extract, preferably in the form of a fluid composition having a concentration of from 0.1 to 99% weight/volume
c. an oxidising agent, preferably in the form of a fluid composition having a concentration of from 0.01 to 1% weight/volume.
According to another aspect of the invention, there is provided a method for sequential treatment of the hair and/or skin by the colouring system according to the invention, comprising the specific sequence of:
treating hair and/or skin with a thio compound capable of breaking the S—S bond between cysteine residues, in the form of an aqueous solution; applying to the hair and/or skin mucuna and/or an extract thereof; and treating the hair and/or skin with an aqueous solution of an oxidising agent.
In a preferred embodiment, the method comprises the specific sequence of
a. treating hair and/or skin with a thio compound capable of cutting the cysteine S—S bond in the form of a fluid composition having a concentration of from 0.01 to 8% weight/volume and an alkaline reagent.
b. applying to the hair and/or skin mucuna and/or its extract in the form of a fluid composition having a concentration of from 0.1 to 99% weight/volume and
c. treating the hair and/or skin with a fluid composition of an oxidising agent having a concentration of from 0.01 to 5% weight/volume.
In a preferred aspect of the invention, the colouring system of the invention is provided as a combination kit comprising the three components mentioned above, said combination kit also having an instruction manual containing instructions for sequential use of the ingredients on hair and/or skin.
DETAILED DESCRIPTION OF THE INVENTION
All parts herein are by weight unless otherwise specified.
The present invention relates to a c
Bhagyalakshmi Krithivasan
Mani Indu
Raman Govindarajan
Elhilo Eisa B
Gupta Yogendra N.
Honig Milton L.
Unilever Home & Personal Care USA , division of Conopco, Inc.
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