WO2014173635A1

WO2014173635A1 - A topical composition for hair growth

Info

Publication number: WO2014173635A1
Application number: PCT/EP2014/056410
Authority: WO
Inventors: Indu Mani; Savitha RAJKUMAR
Original assignee: Unilever NV; Conopco Inc
Current assignee: Unilever NV; Conopco Inc
Priority date: 2013-04-23
Filing date: 2014-03-31
Publication date: 2014-10-30
Anticipated expiration: 2015-10-23

Abstract

The invention relates to a topical composition for hair growth comprising synergistic combination of extracts of plant source. The composition not only retains hair bulb in the anagen state for a longer period of time but also ensures longer length of hair. This is achieved through a composition which comprises a gallic acid ester and an extract of Glycyrrhiza glabra or Sesamum indicum which is applied on the hair or scalp for the desired benefits.

Description

A TOPICAL COMPOSITION FOR HAIR GROWTH

Technical Field

The invention relates to a topical composition for hair growth comprising synergistic combination of materials including extracts of plant source.

Background of the Invention

Hairs are filamentous, keratinized structures consisting of a shaft and a root. The shaft is composed of specialized keratinocytes. The root lies within the hair follicle and comprises the germinative matrix and the keratogenous zone.

There has been continuous effort to find a safe, reliable method of minimizing hair loss or increasing hair growth and thus reducing baldness to various degrees. Though hair loss is not a disease, it bothers the persons concerned

psychologically and seriously affects the individual's self-esteem. The cause for the problem of hair loss is not always the same in all. There are several factors that influence the process by which hair grows and there are many contributory factors that can alter the normal vigorous growth of hair. The hair growth cycle is divided into three phases: an anagen phase, in which the hair is growing actively, with a very substantial level of cell proliferation occurring in the hair follicle; a catagen phase, when the follicle slows down its proliferative activity temporarily to permit hair development; and a telogen phase, in which the follicle simply stops growing and regresses, until the hair is shed, and a new anagen phase begins. It is natural to lose some hair on a daily basis as this is a part of the hair renewal process. This cycling process of hair growth continues throughout the life of an individual. But when this loss becomes excessive it becomes a problem which people try to solve by the use of cosmetic formulations. As appearance and looks are an important aspect in society, hair loss is considered a major problem. Millions of people worldwide suffer from hair loss and are keen to find a solution to treat such hair loss. Different hair growth products and treatments have been developed to solve such a problem but the problem still persists. Compositions comprising extract of plant source are also known.

The present inventors have been working on providing improved hair growth by tackling the problem from two angles - agents that promote health of hair bulb while at the same time increasing the rate of hair bulb growth. They have found that certain synergistic combinations for topical application provide both of these benefits thus ensuring hair that grows long and is healthy. WO 07/084614A discloses a hair treatment composition for topical application to the skin and/or hair, comprising partially hydrolyzed fucoidan and a

pharmaceutical carrier and optionally may also include flavonoids, analgesics, radiation protecting agents, and/or anti-oxidants. IN248853 discloses a composition for minimizing hair loss comprising 0.001 -10% by weight gallic acid or an alkyl ester of gallic acid or a mixture thereof.

The above publications do not disclose the specific combination claimed in the present invention nor provide the enhanced synergistic benefit claimed.

It is thus an object the present invention to obviate the drawbacks of the prior art and provide a topical composition with enhanced hair growth properties.

It is another object of the present invention to provide a topical composition with enhanced hair growth properties that are achieved with combination of materials that are available in nature thereby being mild and safe for use on scalp and hair. Summary of the Invention

The invention relates to a topical composition for hair growth comprising: a. 0.01 to 10% of a gallic acid ester selected from methyl, ethyl or propyl

gallate; b. 0.01 to 10 % of an extract of Glycyrrhiza glabra or Sesamum indicum; and c. a topically acceptable base.

Detailed Description of the Invention These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be utilized in any other aspect of the invention. The word "comprising" is intended to mean "including" but not necessarily "consisting of or "composed of." In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all percentages are weight/weight percentages unless otherwise indicated. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description and claims indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word "about". Numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated. By "A topical composition for hair growth" as used herein, is meant to include a composition for topical application to hair or scalp of mammals, especially humans. By topical is meant that the composition is applied to the external surface of the body. In the present invention this is achieved by applying the composition on the hair or scalp. Compositions for achieving the desired benefits by way of ingestion into the human body are excluded from the scope of the present invention. Such a composition may be generally classified as leave-on or rinse off, and includes any product applied to a human body for also improving the appearance, cleansing, odor control or general aesthetics of scalp and hair. The composition of the present invention can be in the form of a liquid, lotion, cream, foam, scrub, gel, shampoo, conditioner, shower gel or bar. The composition of the present invention is preferably a leave-on composition.

Gallic acid and its esters:

For minimizing hair loss alkyl ester is selected from methyl, ethyl or propyl ester or a mixture thereof. It is particularly preferred that the ester is methyl gallate. The source of methyl gallate is preferably an extract from Acacia nilotica, Mangifera indica, Anachardium oxydentale. Alternately it may be chemically synthesized from gallo tannins using reported procedures.

The source of gallic acid or its esters is synthetic or any gallic acid rich plant source. The source of gallic acid is preferably gall nuts, Terminalia species for e.g. chebula, bellerica, arjuna etc, tea, Embelica officinalis, Mucuna pruriens and other gallic acid rich sources.

Sesamum indicum is also known as Sesamum orientale. The common name is sesame. It is an erect, branched plant that grows to a height of about 60-180 cm. It is an annual plant. It is cultivated throughout the plains of India and also in the hills up to an altitude of about 1200 metres. It is also grown in other countries having climatic conditions like the tropical plains of India mostly as a source of oil seed. It is also used as a spice for seasonings. Sesame is known as Tila, Till, Til, or Gingelli in different regions of India. There are many varieties of sesame grown in India. The varieties are based on the colour of the seed coat which ranges from white to black. There are many intermediate varieties as well. However, the black and white Sesame are two varieties largely cultivated in India.

Of these two varieties, the white sesame is more preferred for use in the present invention. The extract of the second active is preferably present in 0.01 to 2% by weight of the composition, conveniently 0.1 to 1 .0 % by weight of the composition. The extract of Sesamum indicum preferably comprises sesamin, sesamolin, sesamol and sesaminol.

Glycyrrhiza glabra is perennial herb or under shrub attaining a height up to six feet. It is commonly called as licorice, liquorice or mulethi or sweet wood. It is cultivated in India, Spain, Iran, Russia, China, Italy and Persia. In India it is cultivated in Punjab and Sub Himalayan tracts. The root crown gives out a number of long woody stems which bear compound pinnate leaves. Liquorice is known as Jeshtamadha, Jatimadhu, Atimaduram, Atimadhuranu, or Yashtimadhukam in different parts of India. Root and rhizomes are the parts commonly used. The major bio-active constituent of rhizomes are triterpenoids saponin, glycyrrhizin, glycyrrhizinic acid, glabrin A&B, glycyrrhetol, glabrolide, isoglabrolide, isoflavones, coumarins and triterpene sterols.

The extract of Glycyrrhiza glabra, for use in the present invention, preferably comprises higher than 10% of glycyrrhizinic acid. The extract of Glycyrrhiza glabra or Sesamum indicum for use in the composition of the invention preferably an aqueous extract.

The composition of the invention comprises a topically acceptable base. The topically acceptable bases are such as to have a product in preferably a lotion, emulsion, gel, or cream form. The topically acceptable base preferably comprises water. The composition is preferably a gel or a cream. The composition according to the invention may also comprise other diluents. The diluents act as a dispersant or carrier for other materials present in the composition, so as to facilitate their distribution when the composition is applied to the skin. Diluents other than water can include liquid or solid emollients, solvents, humectants, thickeners and powders.

The compositions of the present invention can comprise a wide range of other optional components. The CTFA Cosmetic Ingredient Handbook, Second Edition, 1992, which is incorporated by reference herein in its entirety, describes a wide variety of non-limiting cosmetic and pharmaceutical ingredients commonly used in the skin, scalp and hair care industry, which are suitable for use in the

compositions of the present invention. Examples include: antioxidants, binders, biological additives, buffering agents, colorants, thickeners, polymers, astringents, fragrance, humectants, opacifying agents, conditioners, exfoliating agents, pH adjusters, preservatives, natural extracts, essential oils, skin sensates, skin soothing agents, and skin healing agents.

The invention will now be illustrated with the help of the following non-limiting examples which are by way of demonstration of the invention only and do not limit the scope of the claims.

The extracts of Glycyrrhiza glabra and Sesamum indicum in the following examples were obtained from the supplier Phyto Concentrates who have prepared the extract from plant grown in India. EXAMPLES

In vitro hair bulb culture:

Anagen hair follicles were isolated from scalp biopsies of volunteers undergoing hair transplant operations. Isolated follicles were maintained in William's E Media (Sigma # W 4128) in the absence or presence of various actives. The movement of hair bulbs from anagen (growth phase) to catagen phase (phase of hair fall) was monitored by daily photography and measurement of the size of the hair bulb.

Preparation of actives:

Methyl gallate (MG) was purchased from Sigma and aqueous extracts of all herb samples were purchased from Phyto Concentrates. These were prepared in water as 1 % solution and stored at -20°C. Further dilutions of MG and herbs and their combinations were prepared in the media just before addition to the hair follicle culture. The actives were added fresh every time the media was changed (every alternate day) and the growth was followed for a period of 4 days. Morphology of hair bulb and change in length was recorded for every time point (Day 0, Day 2 and Day 4). Each experiment was conducted at least with 6-8 hair follicles per group and the results are averages of 3-5 experiments per active.

Various herbs were tested of which Sesamum indicum (S.indicum) and

Glycyrrhiza glabra (G. glabra) in combination with methyl gallate showed both growth and bulb retention in the invitro hair follicle. The methyl gallate was tested at concentrations of 10 and 50 ppm and the herb extracts were tested at at concentrations of 125, 250 and 500 ppm. The summary of the data on % hair growth and % bulbs retained in anagen ph is summarised in Table 1 .

Table 1

It is essential that there is need to maximize growth of hair as well as maximize retention of hair bulbs in the anagen phase. The data in Table 1 above indicates that while herb extract causes hair growth it does not cause retention of hair bulbs in anagen phase while methyl gallate does both albeit at low levels. The data in the above table especially the highlighted and underlined data indicate that it is possible to improve retention of intact bulbs while maintaining good hair growth by a judicious combination of herb extracts chosen from G. glabra and S.indicum. Such improvement in both these properties is not observed when extracts of other herbs are used.

It is to be appreciated that the concentration of the herb and the gallic acid ester in the above experiments correspond to in-vitro hair bulb conditions. The actual amount of these actives to be included in a composition for hair growth has to be orders of magnitude higher, to account for various factors including loss of active due to possible stability issues in the composition over storage and use, efficiency of spreading of the composition on the hair/ scalp, availability of the active from the bulk of the composition to the desired surface, diffusion of the active from the desired surface to the active site where the biochemical reaction occurs among various other known and unknown factors. Thus from experience, the inventors are aware that use of ppm levels of active in an in-vitro assay generally requires percentage levels of incorporation of the actives in a compostion. The invention thus provides for a composition for hair growth comprising a judicious combination of natural materials.

Claims

C LAI MS

1 . A topical composition for hair growth comprising: a. 0.01 to 10% of a gallic acid ester selected from methyl, ethyl or propyl gallate; b. 0.01 to 10 % of an extract of Giycyrrhiza glabra or Sesamum indicum; and c. a topically acceptable base.

2. A composition as claimed in claim 1 wherein said gallic acid ester is methyl gallate.

3. A composition as claimed in claim 1 or 2 wherein the gallic acid ester is

extracted from a plant source selected from Acacia nilotica, mangifera indica or anachardium oxydentale.

4. A composition as claimed in any one of the preceding claims wherein the extract of Giycyrrhiza glabra or Sesamum indicum is an aqueous extract.

5. A composition as claimed in claim 4 wherein the extract of Giycyrrhiza glabra comprises higher than 10% of glycyrrhizinic acid.

6. A composition as claimed in claim 4 wherein the extract of Sesamum

indicum comprises sesamin, sesamolin, sesamol and sesaminol.

7. A composition as claimed in any one of the preceding claims wherein the topically acceptable base comprises water.

8. A composition as claimed in claim 7 wherein said topically acceptable base is a gel or a cream.

9. A process for growing hair comprising applying to the hair or scalp a

composition as claimed in any one of the preceding claims for at least 10 minutes.