WO2013060710A2

WO2013060710A2 - A topical composition

Info

Publication number: WO2013060710A2
Application number: PCT/EP2012/071022
Authority: WO
Inventors: Anita DAMODARAN; Aparna DAMLE; Vikramjit Singh; Sreenivasa THIMMAIAH
Original assignee: Unilever N.V.; Unilever Plc; Hindustan Unilever Limited; Conopco, Inc., D/B/A Unilever
Priority date: 2011-10-28
Filing date: 2012-10-24
Publication date: 2013-05-02
Also published as: AR088549A1; WO2013060710A3

Abstract

The present invention relates to an anti-inflammatory and skin lightening topical composition. We have found out that though US 2010/01 19463 discloses an antioxidant cosmetic skin care composition for improving the appearance of aged or damaged skin, it is not significantly effective in providing desirable anti-inflammation benefit. Therefore there is a need to develop a topical composition for skin damage prevention (anti-inflammatory benefit) thereby improving skin appearance of the individuals. It is another object of the present invention to provide a topical composition for anti-inflammation benefit. The present inventors have surprisingly found that a combination of green tea and black tea extract in a particular range of ratios provides a topical composition which has improved anti-inflammation benefit and thus provides better skin appearance.

Description

A TOPICAL COMPOSITION

Technical field The present invention relates to a topical composition. More particularly the present invention relates to a topical composition for providing skin-benefits.

Background Highly pleasing skin appearance is one of the most desired expectations from personal care products from most consumers around the world. Various physical and chemical insults disrupt the normal functioning of the skin, Ultraviolet (UV) radiation being one of them. Excessive exposure to UV radiation leads to increased skin inflammation (reddening, swelling, and itching), increased pigmentation and premature ageing which in turn affects the skin appearance. In tropical countries where consumers generally have dark skin, there is a desire to have lighter skin appearance. In Caucasian and South East Asian consumers who generally have lighter skin, there is a problem of freckles and hyper pigmentation when they are exposed to bright sunshine especially in aged individuals and therefore they desire an evenly toned skin. Most consumers experience blemishes on their skin after exposure to sun, on healing of wounds or after drying up of acne. In consumers with sensitive skin, day to day use of detergents and soaps also causes subclinical inflammatory responses. In all of the above cases, consumers rely on cosmetic solutions to their skin appearance problems. There is possibility to protect the skin from harmful UV radiation by using skin cream which has sunscreens or sunblocks. Sunscreens are generally organic molecules that absorb the UV radiation and emits the energy in a different form, for instance in the visible range of the spectrum or in the form of heat, thereby protecting the skin against irritation and sunburn. Sunscreens are generally small organic molecules. But sometimes these skin creams are not that efficient to give full protection. Also, the protection offered by these types of creams is highly dependent on the exposure time to the sun. If the exposure time is quite long then there is a possibility of inflammation even after applying a sunscreen containing cream on the skin. Sunblocks are also used in skin creams for protecting harmful radiation. Sunblocks are used either alone or along with sunscreen to physically block the sunlight by creating a layer on the skin.

Though consumers like to apply skin cream for preventing possible inflammation and for improving the skin appearance, they also at the same time prefer to use a skin cream that includes natural substance as actives.

Incorporation of natural substances in topical compositions for improving the appearance of aged or damaged skin is known. US 2010/01 19463 (Jacobs, 2010) disclose an antioxidant cosmetic skin care compositions formulated to combat conditions associated with free radical damage and oxidative stress. The compositions contain effective amounts of one of several active agents, including an agent derived from one or more of the plant species: Lycium barbarum, Punica granatum, Vitis vinifera, Aspalathus linearis, and Camellia Sinensis as well as cosmetically acceptable carriers. These cosmetic compositions find use in improving the appearance of aged or damaged skin.

We have found out that, though US 2010/01 19463 discloses an antioxidant cosmetic skin care composition for improving the appearance of aged or damaged skin, it is not significantly effective in providing desirable anti-inflammation benefit.

Therefore there is a need for developing a topical composition for skin damage prevention (anti-inflammatory benefit) thereby improving skin appearance of the individuals.

Objects of the invention

It is therefore an object of the present invention is to overcome or ameliorate at least one of the disadvantages of the prior art.

It is another object of the present invention to provide a topical composition for anti- inflammation benefit. It is a further object of the invention to provide a topical composition for improved skin appearance.

It is yet another object of the present invention to provide a topical composition for improved skin appearance which includes natural substances as actives.

The present inventors have surprisingly found that a combination of green tea and black tea extract in particular ratio provides a topical composition which meets one or more of the aforesaid objects.

Summary of the invention

Accordingly in a first aspect of the present invention there is provided a topical composition comprising;

(a) 0.01 to 10% of a mixture of green tea and black tea extract of the Camellia sinensis species; and,

(b) a cosmetically acceptable base,

characterized in that the ratio of green tea extract to black tea extract is from 2:1 to 7:1 . According to the second aspect of the present invention there is provided the use of a topical composition of the first aspect for anti-inflammation benefit.

According to the third aspect of the present invention there is provided the use of a topical composition of the first aspect for improved skin appearance.

According to the fourth aspect of the present invention there is provided the use of a topical composition of the first aspect for preventing post-inflammatory pigmentation.

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. For the avoidance of doubt, any feature of one aspect of the present invention may be utilised 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 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.

Detailed description of the invention

The present invention provides a topical composition comprising;

(b) a cosmetically acceptable base,

characterized in that the ratio of green tea extract to black tea extract is from 2:1 to 7:1 . Topical composition means, the composition is suitable for application on the skin. The topical composition of the invention preferably comprises 0.1 to 8 %, more preferably 0.5 to 8%, further more preferably 1 to 6% and most preferably 1 to 5% and further most preferably 1 to 3% of a mixture of green tea and black tea extract of Camellia sinensis species. All the above mentioned percentage is on solid weight basis of the composition. If the composition is having high percentage of water then the percentage of the mixture of green tea and black tea extract as mentioned above has to construe accordingly. The preferable ratio of green tea extract to black tea extract is from 2:1 to 6:1 and more preferably 2:1 to 5:1 . Both, the green tea extract and the black tea extract are from the Camellia sinensis species. The green tea extract and the black tea extract preferably include extract from one or more of the leaf, the bud, the stem or combinations of these parts of Camellia sinensis species. There is no preference of the geographical origin of the Camellia sinensis species.

The green tea extract comprises preferably 30 - 50 % of polyphenols by dry weight of green tea extract. More preferably the green tea extract comprises 32 -50%, further more preferably 35-50% and most preferably 37-50% of polyphenols by weight of green tea extract.

The green tea extract of the topical composition comprises preferably 15 - 30%, more preferably 17 - 30% and most preferably 20 - 30% of catechins by dry weight of green tea extract.

The amount of epigallocatechin in the green tea extract preferably is in between 6 - 12%, more preferably 7- 12% and most preferably 8 - 12% by dry weight of green tea extract.

The topical composition of the present invention also comprises black tea extract. The black tea extract comprises preferably 25 - 40%, more preferably 28 - 40% and most preferably 30 - 40% of polyphenols by dry weight of black tea extract.

The black tea extract used preferably an aqueous extract of black tea. The aqueous extract of black tea is preferably made by extracting the black tea leaf with water in a ratio of 1 :5 to 1 :30 at a temperature of 80 - 98°C for 10 minutes to 2 hours. This may be achieved either by putting the tea leaf for the above mentioned time in water maintained at 80 - 98°C or heating the water to 80 - 98°C along with the tea leaf for 10 minutes to 2 hours. After the extraction process preferably the extract is subjected to centrifugation to separate out the residual leaf and the supernatant which comprises the aqueous extract. Then the supernatant is dried preferably in a spray dryer to get the black tea aqueous extract (in powder form). Optionally the supernatant (as it is or in diluted or in concentrated form) obtained after centrifugation which comprises the aqueous extract may also be used for making the composition of the present invention. The green tea extract preferably made by using the same protocol for making the black tea extract. Optionally commercially available green tea/black tea powder with the particular specification as stated above (in terms of polyphenols content, catechins content and epigallocatechin content) may also be used.

The topical composition comprises a cosmetically acceptable base. The cosmetically acceptable base is preferably a cream, lotion, gel or emulsion.

The composition of the invention comprises a cosmetically acceptable vehicle. The cosmetically acceptable vehicle is usually from 10 to 99.9%, preferably from 50 to 99% by weight of the composition. The cosmetically acceptable vehicle preferably comprises 1 to 25% fatty acid. The cosmetically acceptable vehicles are preferably in a cream, lotion, gel or emulsion format. A more preferred format is a cream; further more preferably a vanishing cream. Vanishing cream base is one which comprises 1 to 25%, more preferably 5 to 20% fatty acid. The base preferably comprises 0.1 to 10%, more preferably 0.1 to 3% soap. C12 to C20 fatty acids are especially preferred in vanishing cream bases, further more preferred being C14 to C18 fatty acids. In creams, the fatty acid is preferably substantially a mixture of stearic acid and palmitic acid. Soaps in the vanishing cream base include alkali metal salt of fatty acids, like sodium or potassium salts. The soap is preferably the potassium salt of the fatty acid mixture. The fatty acid in vanishing cream base is often prepared using hystric acid which is substantially (generally about 90 to 95%) a mixture of stearic acid and palmitic acid. Thus, inclusion of hystric acid and its soap to prepare the vanishing cream base is within the scope of the present invention. It is particularly preferred that the composition comprises at least 6%, preferably at least 10%, more preferably at least 12% fatty acid. The cosmetically acceptable vehicle preferably includes water. Water is preferably included in 35 to 90%, more preferably 50 to 85%, further more preferably 50 to 80% by weight of the composition. The composition of the invention may additionally comprise a skin lightening agent. The skin lightening agent is preferably chosen from a vitamin B3 compound or its derivative e.g. niacin, nicotinic acid, niacinamide or other well known skin lightening agents e.g. aloe extract, ammonium lactate, arbutin, azelaic acid, kojic acid, butyl hydroxy anisole, butyl hydroxy toluene, citrate esters, 3 diphenyl propane derivatives, 2, 5 dihydroxybenzoic acid and its derivatives, ellagic acid, fennel extract, gluco pyranosyl-1 -ascorbate, gluconic acid, glycolic acid, green tea extract, hydroquinone, 4 hydroxyanisole and its derivatives, 4-hydroxy benzoic acid derivatives, hydroxycaprylic acid, lemon extract, linoleic acid, magnesium ascorbyl phosphate, mulberry root extract, 2,4 resorcinol derivatives, 3,5 resorcinol derivatives, salicylic acid, vitamins like vitamin B6, vitamin B12, vitamin C, vitamin A, a dicarboxylic acid, resorcinol derivatives, hydroxycarboxylic acid like lactic acid and their salts e.g. sodium lactate, and mixtures thereof. Vitamin B3 compound or its derivative e.g. niacin, nicotinic acid, niacinamide are the more preferred skin lightening agent as per the invention, most preferred being niacinamide. Skin lightening agent, when used, is preferably present in an amount in the range of 0.1 to 10%, more preferably 0.2 to 5% by weight of the composition. Additionally inorganic sunscreens and/or sun-blocks are used in the composition of the present invention.

The composition preferably includes sunscreens like 4-t-butyl-4'- methoxydibenzoylmethane which is known as Avobenzone TM or Parsol 1789 TM. Most of the consumer care products that intend to protect the skin against UV radiation use Parsol 1789. Avobenzone TM is also available in the trade name of Parsol 1789TM, Eusolex 9020 TM, Escalol 517 TM and many others. This is an oil soluble ingredient used in sunscreen products to provide protection against the full spectrum of UVA rays. Avobenzone exists in the ground state as a mixture of the enol and keto forms, favoring the chelated enol. It is able to absorb ultraviolet light over a wider range of wavelengths compared to many organic sunscreen agents.

The personal care composition of the invention optionally can have UVB sunscreens also like para-methoxy cinnamic acid and its derivative e.g. ethylhexyl

methoxycinnamate which is known as Parsol MCX TM, to protect entire gamut of UV rays. According to the invention, the personal care composition optionally comprises 0.1 to 10% preferably 0.1 to 6% of sunscreen by weight of the composition. Inclusion of p-methoxycinnamic acid derivative is especially useful since in addition to providing the known UV-B protection, the personal care composition ensures better stability of Parsol 1789 in the presence of p-methoxycinnamic acid derivative.

The preferable examples of sunblocks include zinc oxide, iron oxide, silica, such as fumed silica, and titanium dioxide.

Ultrafine titanium dioxide in either of its two forms, namely water-dispersible titanium dioxide and oil- dispersible titanium dioxide is especially suitable for the invention. Water-dispersible titanium dioxide is ultra-fine titanium dioxide, the particles of which are non-coated or which are coated with a material to impart a hydrophilic surface property to the particles. Examples of such materials include aluminium oxide and aluminium silicate.

Oil-dispersible titanium dioxide is ultrafine titanium dioxide, the particles of which exhibits a hydrophobic surface property, and which, for this purpose, can be coated with metal soaps such as aluminium stearate, aluminium laurate or zinc stearate, or with organosilicone compounds.

By "ultrafine titanium dioxide" is meant particles of titanium dioxide having an average particle size of less than 100 nm, preferably 70 nm or less, more preferably from 10 to 40 nm and most preferably from 15 to 25 nm.

By topical application to the skin of a mixture of both water- dispersible ultrafine titanium dioxide and oil-dispersible ultrafine titanium dioxide, synergistically enhanced protection of the skin against the harmful effects of both UV-A and UV-B rays is achievable.

Ultrafine titanium dioxide is the preferred inorganic sun-block agent. The total amount of sun block that is preferably incorporated in the composition according to the invention is from 0.1 to 5% by weight of the composition. 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. Examples of each of these types of vehicle, which can be used singly or as mixtures of one or more vehicles, are as follows:

Emollients, such as stearyl alcohol, glyceryl monoricinoleate, mink oil, cetyl alcohol, isopropyl isostearate, stearic acid, isobutyl palmitate, isocetyl stearate, oleyl alcohol, isopropyl laurate, hexyl laurate, decyl oleate, octadecan-2-ol, isocetyl alcohol, eicosanyl alcohol, behenyl alcohol, cetyl palmitate, silicone oils such as

dimethylpolysiloxane, di-n-butyl sebacate, isopropyl myristate (IPM), isopropyl palmitate, isopropyl stearate, butyl stearate, polyethylene glycol, triethylene glycol, lanolin, cocoa butter, corn oil, cotton seed oil, olive oil, palm kernel oil, rape seed oil, safflower seed oil, evening primrose oil, soybean oil, sunflower seed oil, avocado oil, sesame seed oil, coconut oil, arachis oil, castor oil, acetylated lanolin alcohols, petroleum jelly, mineral oil, butyl myristate, isostearic acid, palmitic acid, isopropyl linoleate, lauryl lactate, myristyl lactate, decyl oleate, myristyl myristate;

Solvents, such as ethyl alcohol, isopropanol, acetone, ethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether;

Powders, such as chalk, talc, fullers earth, kaolin, starch, gums, colloidal silica sodium polyacrylate, tetra alkyl and/or trialkyl aryl ammonium smectites, chemically modified magnesium aluminium silicate, organically modified montmorillonite clay, hydrated aluminium silicate, fumed silica, carboxyvinyl polymer, sodium carboxymethyl cellulose, ethylene glycol monostearate. The cosmetically acceptable vehicle is usually from 10 to 99.9%, preferably from 50 to 99% by weight of the composition, and can, in the absence of other personal care adjuncts, form the balance of the composition. The composition of the invention may comprise a conventional deodorant base as the cosmetically acceptable carrier. By a deodorant is meant a product in the stick, roll-on, or propellant medium which is used for personal deodorant benefit e.g. application in the under-arm area which may or may not contain anti-perspirant actives.

Deodorant compositions can generally be in the form of firm solids, soft solids, gels, creams, and liquids and are dispensed using applicators appropriate to the physical characteristics of the composition. Deodorant compositions which are delivered through roll-ons generally comprise a liquid carrier. Such liquid carrier can be hydrophobic or comprise a mixture of both hydrophilic and hydrophobic liquids. They may be in the form of an emulsion or a microemulsion. The liquid carrier or mixture of carriers often constitutes from 30 to 95% by weight of the composition and in many instances from 40 to 80%. Hydrophobic liquid carriers commonly can comprise one or more materials selected within the chemical classes of siloxanes, hydrocarbons, branched aliphatic alcohols, esters and ethers that have a melting point not higher than 25 °C and a boiling point of at least 100°C. Hydrophilic carrier liquids that can be employed in compositions herein commonly comprise water and/or a mono or polyhydric alcohol or water-miscible homologue. Monohydric alcohols often are short chain, by which is meant that they contain up to 6 carbons, and in practice is most often ethanol or sometimes iso-propanol. Polyhydric alcohols commonly comprise ethylene or propylene glycol, or a homologue can be employed such as diethylene glycol. Other than this suitable other vehicle and component used for deodorant composition can be added. The compositions of the present invention can comprise a wide range of other optional components. The CTFA Personal care Ingredient Handbook, Second Edition, 1992, which is incorporated by reference herein in its entirety, describes a wide variety of non-limiting personal care and pharmaceutical ingredients commonly used in the skin 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 composition is formulated in any known format, more preferred formats being creams or lotions. UV exposure creates inflammation in the skin and also hampers appearance of the skin. The present invention provides the use of a topical composition according to the invention for anti-inflammation benefit. The present invention also provides the use of a topical composition according to the invention for improved skin appearance. The present invention further provides the use of a topical composition according to the invention for improved skin lightening. The present invention yet further provides the use of a topical composition according to the invention for preventing post-inflammatory pigmentation.

Now the invention will be demonstrated with the help of following non-limiting examples.

Examples

Making the topical composition of the invention:

The topical compositions were prepared using as per the following Table 1 :

Table: 1

Ingredients Example Number

(Weight %) A B 1 C 2 D

Glycerine

1 1 1 1 1 1

Disodium EDTA

0.04 0.04 0.04 0.04 0.04 0.04

Potassium hydroxide

0.57 0.57 0.57 0.57 0.57 0.57

Methyl paraben

0.2 0.2 0.2 0.2 0.2 0.2

Hystric acid

17.9 17.9 17.9 17.9 17.9 17.9

IPM Propyl paraben

0.1 0.1 0.1 0.1 0.1 0.1

Cetyl alcohol

0.52 0.52 0.52 0.52 0.52 0.52

Parsol 1789

0.4 0.4 0.4 0.4 0.4 0.4

Parsol MCX

1 .25 1 .25 1 .25 1 .25 1 .25 1 .25 phenoxy ethanol

0.4 0.4 0.4 0.4 0.4 0.4

Silicone oil

0.5 0.5 0.5 0.5 0.5 0.5

Micro ΤΊ02

0.2 0.2 0.2 0.2 0.2 0.2

Perfume

0.35 0.35 0.35 0.35 0.35 0.35

Colour

0.0006 0.0006 0.0006 0.0006 0.0006 0.0006

Green Tea

2 0 1 .75 1 1 .5 0.5

Black Tea

0 2 0.25 1 0.5 1 .5

Water

To 100 To 100 To 100 To 100 To 100 To 100

The topical compositions were made using the following protocol:

All the water soluble ingredients of Table 1 water, glycerine, and, potassium hydroxide were added together and heated on a heater until it reached the temperature of 80±2°C. Simultaneously, the oil phase (hystric acid) was also heated separately on a heater until it reaches the temperature of 82±2°C. The oil phase was then added to the water phase prepared before and homogenized slowly by using a homogenizer (Silverson L5M-A) at ~ 3000 rpm.

After that, cetyl alcohol. Parsol 1789, parsol MCX, IPM, phenoxy ethanol and silicone oil were added together in a separate vessel and heated on a heater until it reaches the temperature of 68±2°C. This solution was then added to the homogenized mixture of the previous step when the temperature of the mixture was around 65-70°C. At the same time the green tea and the black tea extract was added into this mixture. Titanium

Dioxide was also added at the same time. The mixture was then cooled down to ~ 45°C, followed by homogenizing it for few minutes. The formulation vessel was then placed in a dessicator with attached vacuum pump. The air bubbles were removed by using the vacuum pump.

For making the above formulations the green tea powder extract was commercially obtained from Synthite Industries Ltd., Kerala, India. The green tea extract obtained was characterized by having 34.6% of polyphenols, 23.5% of catechins and 8.5% of epigallocatechin by dry weight of the green tea extract.

The black tea extract was made by taking Lipton Yellow label leaf tea product available in the market. Then the leaf tea product was extracted with water in a ratio of 1 :20 at a temperature of 92±2°C for 45 minutes. After the extraction process the extract was subjected to ultra filtration to obtain concentrated extract and then it was dried in a spray dryer to obtain the black tea extract powder. The black tea powder extract was characterized by having 30% of polyphenols by dry weight basis.

Anti-irritation study (patch test) with the formulations made according to Tablel

Protocol: Ten healthy volunteers (panelists) of age between 18 to 55 years were selected based on their medical history (people with heart problems, diabetes, allergic to sun- exposure, under medication, pregnant/lactating women or with any other major health problems were excluded). The test was performed with their consent and written approvals were taken from them before carrying out the test. Panelists were asked not to apply any topical applications 24 hours before the test.

On the first day test samples (according to Table 1 ) at a level of -150 mg were applied in patches (patches were obtained from SmartPractice ® having Finn Chamber diameter of 12 mm) in occlusion on the upper arm of the panelists. After 24 hours (second day), the patches were carefully removed and any excess cream which is still sticking on to the skin was carefully removed using a wet tissue paper. SDS was used as an irritant. The area of the Finn Chamber was marked on the arm with marker. After that 40 micro liters of 3% SDS (sodium dodecyl sulphate, 99% purity from Sigma®) was applied on the same areas where the samples were applied in the first day with a control (a patch that has only SDS applied on skin where there was no formulation was applied on the first day) under occlusion. After 24 hours (third day) the patches were removed and the areas were remarked by a marker. After another 24 hours (fourth day), the area under the patches were observed and evaluated by a skilled

dermatologist and the score were given which are summarized in the following Table 2.

The scale of evaluation was from Ό-8', wherein '8' represents maximum level of irritation and Ό' represent no irritation.

Table: 2

From the above table it is evident that example number 1 and 2 which is inside the scope of the present invention provides much higher reduction in irritation (having the lowest irritation score) than example numbers A, B, C or D which are outside the scope of the present invention. This indicates that the compositions made according to the present invention provide improved anti-inflammation benefit.

Post-inflammatory pigmentation study (patch test) with the formulation that has given best result in anti-irritation study

From Table 2 It is evident that Example 2 gives higher reduction in irritation than any other composition. Therefore it was decided to check whether this formulation also works in Post-inflammatory pigmentation study (patch test). The study was carried out using the following protocol:

All volunteers were asked to visit the clinical site for 5 consecutive days. The study was conducted in presence of a trained dermatologist. Pre-screening medical history and informed consent was obtained on the first day. On the second day, Colour

measurements (L^* value - lightness) were taken using a hand held Minolta

Chromameter model number CR-10 at the site of patch application. Patches (patches were obtained from SmartPractice ® having Finn Chamber diameter of 12 mm) with formulation of Example 2 and a base formulation which does not have any green tea or black tea but all other ingredients as mentioned in Table 1 (both at a level of~150 mg), were applied on the left/right upper arms. On the third day, the patches were carefully removed and gently wiped with tissue and water. On the same sites, patches with 40 μΙ_ of 3% SDS (sodium dodecyl sulphate, 99% purity from Sigma®) were applied. On the fourth day, all patches were carefully removed and gently wiped with tissue. The volunteers were advised to avoid wetting the site with water or scratching on all these days. On the fifth day, the patched areas were observed for inflammation by the dermatologist similar to as mentioned in the previous section. The volunteers were called again after 2 weeks and the post-inflammatory pigmentation (The L^* values were taken again) was measured with Minolta Chromameter CR 10. The values were subtracted from baseline measured on day 1 and delta L values were calculated to determine the post inflammatory pigmentation caused by SDS in presence of the composition of Example 2 and the base composition. The results are summarized below in Table 3

Table: 3

In Table 3, lower the 'Delta L^*' value better the formulation is in preventing

pigmentation. From the above Table 3 it is evident that composition of example 2 provides good prevention of post-inflammatory (inflammation caused by the applied SDS)

pigmentation. Anti-melanogenic assay with green tea and black tea extracts at various ratios Protocol:

Primary melanocytes, isolated from darkly pigmented human neonatal foreskin (Negroid origin) were procured from Invitrogen under the brand name Cascade Biologies®. Cells obtained and stored under liquid nitrogen were thawed at 37°C and cultured in 25 sqcm cell culture flasks in melanocyte growth media [MGM254 obtained from Invitrogen under the brand Gibco® + HMGS-2 (from Gibco) + Antibiotics] under sterile conditions. The antibiotics which were added to the melanocytes growth media was prepared by adding 1 million units of penicillin obtained from Himedia and 10 g of Streptomycin sulphate obtained from sigma, in 100 mL of distilled autoclaved water. This solution was stirred well, aliquoted and stored it in a freezer of temperature -20°C.

1 mL of this solution was added in 1 L of melanocytes growth media. The cells were cultured until they were -80% confluent. After that they were further subcultured before they were used for the assay. All the cell cultures were incubated at 37°C with 5% carbon dioxide gas. The cells were seeded in a 24-well plate at a density of 5x10⁴ cells per well in melanocytes growth media in duplicates and incubated at 37°C with 5% carbon dioxide gas. After 24 hours the spent media was carefully discarded and fresh media containing MBM-4 (melanocytes basal media without calcium obtained from Lonza, sold under Clonetics™), growth factors and actives (green tea and/or black tea extract) at different ratios were added. The growth factors supplement for this purpose was obtained from Lonza (Cat No. CC-3250) as a kit which comprises calcium chloride, PMA, rhFGF-B, rh-insulin, BPE, hydrocortisone, FBS and GA-1000. From the above said kit 1 mL of calcium chloride, 0.5mL of PMA, 1 mL of rhFGF-B, 1 mL of rh-insulin,

2 mL of BPE, 0.5 mL of hydrocortisone, 2.5 mL of FBS and 0.5 mL of GA-1000 were added in 500 mL of MBM-4 media. The total volume of the media was 500 micro liters per well and the total concentration of actives was 12.5 ppm. After 1 hour of active addition alpha- Melanocyte Stimulating Hormone (NDP-MSH from calbiochem, Cat no. 05-23-0756) was added at a concentration of 10 nano-molar. After 72 hours of incubation spent media was again carefully discarded. Then the plates were carefully rinsed with phosphate buffer saline- Ca-Mg buffer of pH 7.4 followed by addition of 200 mL of the same buffer containing 1 micro molar of calcein-AM (from Sigma®). This solution was then incubated for 30 minutes under the condition as specified above. Then the fluorescence was measured (using TECAN, model - infinite® M1000) at excitation wavelength of 490 nanometers and emission wavelength of 520 nanometer to find out the cell viability. Buffer containing fluorescent dye without cells was used as a blank and buffer containing fluorescent dye with cells but without green tea (GT) and black tea (BT) was used as a control. The buffer used above was prepared by adding 5 ml of solution A (49.4 g of anhydrous Na₂HP0₄ + 10.92 g dihydrated NaH₂P04 in 1 L of distilled water) and 5 mL of solution B(2.6 g CaCI₂ + 5.22 g KCI + 3.66 g MgCI₂ + 160.3 g NaCI in 1 L of distilled water) in 90 mL of distilled water. The buffer was carefully discarded and 100 microlitres of MCA (Melanin content assay) reagent (10% dimethyl sulphoxide in 1 N NaOH) was added to each well and incubated in an incubator shaker for 1 hour at 60°C. It was then followed by transfer of 80 micro liter of the above solution into a 384 well plate and the absorbance was measured at a wavelength of 405 nanometer, to find out the melanin content. The above procedure was followed for different ratios of actives along with a control where there was no active. All data set were repeated six times and then the averages were calculated. For non-cytotoxic concentrations of green tea and black tea (based on cell viability), the results were calculated as a ratio of average MCA value/average cell viability value and expressed as %of control (here the control is cells treated with alpha-MSH alone without GT and BT).

The results are summarized below in Table 4. Table: 4

Example number H is a control where it is taken as 100% melanin content and all the other values were calculated with respect to % of H. From the above table it is evident that example number 3, 4, 5 and 6 which are inside the scope of the present invention provides higher decrease in melanin generation than example numbers E, F or G which are outside the scope of the present invention.

Claims

Claims:

1 . A topical composition comprising ;

(b) a cosmetically acceptable vehicle,

characterized in that the ratio of green tea extract to black tea extract is from 2:1 to 7:1 .

2. A composition as claimed in claim 1 where the ratio of green tea extract to black tea extract is from 2:1 to 5:1.

3. A topical composition as claimed in claim 1 or 2 wherein the green tea extract comprises 30 - 50 % of polyphenols by dry weight of green tea extract.

4. A topical composition as claimed in any one of the preceding claims 1 to 3

wherein the green tea extract comprises 15 - 30% of catechins by dry weight of green tea extract.

5. A topical composition as claimed in claim 4 comprising 6 - 12%

epigallocatechin by dry weight of green tea extract.

6. A topical composition as claimed in any one of the preceding claims comprising 25 - 40% of polyphenols by dry weight of black tea extract.

7. A composition as claimed in any one of the preceding claims wherein the

cosmetically acceptable vehicle comprises 1 to 25 % of fatty acid by weight of the composition.

8. A composition as claimed in any one of the preceding claims wherein the black tea extract and/or the green tea extract is an aqueous extract.

9. A composition as claimed in any one of the preceding claims wherein the cosmetically acceptable base comprises 0.1 to 10% of soap by weight of the composition.

10. A composition as claimed in any one of the preceding claims further comprising sunscreens and/or sunblocks.

1 1 . A composition as claimed in claim 10 wherein the sunscreen comprises para- methoxy cinnamic acid or its derivatives.

12. The use of a topical composition as claimed in any of the preceding claims for anti-inflammation benefit.

13. The use of a topical composition as claimed in any of the preceding claims for improved skin appearance.

14. The use of a topical composition as claimed in any of the preceding claims for improved skin lightening.

15. The use of a topical composition as claimed in any of the preceding claims for preventing post-inflammatory pigmentation.