A personal care composition

Abstract

The present invention relates to a personal care composition. The composition especially relates to delivering antimicrobial benefit using environmentally sustainable ingredients. This is achieved through a composition that comprises a biosurfactant comprising a glycolipid and an anti-microbial peptide (AMP) booster.

Description

[0001] A PERSONAL CARE COMPOSITION

[0002] Field of the Invention

[0003] The present invention relates to a personal care composition. The composition especially relates to delivering antimicrobial benefit using environmentally sustainable ingredients.

[0004] Background of the Invention

[0005] Skin is the primary line of defence that protects the human body from invading pathogens, like virus and bacteria. As a primary defence organ, the skin tissue always remains in constant contact with the environment and therefore it has to face and resolve threats and challenges from invading pathogens. The exposed skin surface is not only challenged by pathogenic foreign bacteria, but it also remains in contact and interacts with the resident commensal bacteria. In spite of all these challenges from such foreign microbes, healthy skin remains infection free and also the numbers of the resident microflora remains generally constant. This equilibrium in the interaction between the skin tissue and the microbes is maintained as the skin has sophisticated defence strategy of which anti-microbial peptides (AMPs) form an important part.

[0006] AMPs form an integral part of the skin’s own defence system. AMPs are ubiquitous in nature and they typically exhibit a broad spectrum of activity against invading bacteria, fungi, viruses and parasites. AMPs are generally short peptides and in humans about 90 different AMPs are reported to be present. AMPs in general have two major physical features and they have - a) cationic charge and b) a significant proportion of hydrophobic residues. The cationic charge of the AMPs promotes selectivity for negatively charged microbial surfaces whereas the hydrophobicity facilitates interactions with the cell membrane of the microbial species.

[0007] The present inventors have been working to provide hygiene benefits to consumers through the route of enhancing the AMP levels in the skin. In the course of their work in this area over several years they have found many molecules that enhance AMPs and filed patent applications on them. In the course of utilising this knowledge and their constant search for actives that could potentially interact with known AMP boosters to deliver enhanced antimicrobial activity, they found that a class of biosurfactants viz. ones which comprise a glycolipid group is capable of providing this enhanced activity. Thus, the benefit obtained by the consumer is that the skin is protected against germs that may attack in the future.

[0008] Additionally, these biosurfactants by nature being more biodegradable have sustainability benefits thereby being more acceptable to consumers.

[0009] It is thus an object of the present invention to provide for combination of actives that deliver enhanced antimicrobial efficacy. Summary of the Invention

[0010] The first aspect of the present invention relates to a personal care composition comprising

[0011] (i) A biosurfactant comprising a glycolipid and

[0012] (ii) 0.05 to 5 wt% an anti-microbial peptide (AMP) booster selected from one or more of hydroxystearic acid; nicotinamide; isomer of nicotinamide, cycloalkyl derivatives of nicotinamide, Vitamin A, Vitamin C and linseed oil;

[0013] (iii) a cosmetically acceptable vehicle’ wherein said biosurfactant is chosen from one or more of rhamnolipid, sophorolipid, trehalolipid or mannosylerythritol lipid (MEL); and wherein, when the biosurfactant is a sophorolipid, it comprises higher than 50 wt% lactonic sophorolipid.

[0014] Another aspect of the present invention relates to a method of disinfecting an external surface of a human body comprising the step of applying onto the surface a composition of the first aspect on to the desired skin surface.

[0015] Detailed Description of the Invention

[0016] 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 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 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. The topical composition of the invention is meant to be used for personal care or for cosmetic use and could also be referred to as a personal care composition or a cosmetic composition. By a “personal care composition” as used herein, is meant to include a composition for topical application i.e external surfaces of the skin and / or hair of humans. Such a composition may be classified as leave-on or wash off, and includes any product applied to a human body for improving appearance, cleansing, odour control or general aesthetics. The composition is preferably of the wash-off type. The composition of the present invention can be in the form of a liquid, lotion, cream, paste, powder, emulsion, foam, stick, roll-on, gel or through an aerosol containing composition. Preferred compositions include a cream, lotion, gel, paste, powder or emulsion.

[0017] "Skin" as used herein is meant to include skin on the face and body e.g., neck, chest, back, arms, underarms, hands, legs and scalp.

[0018] The composition as per the invention comprises a biosurfactant comprising a glycoplipid. The biosurfactant is preferably chosen from one or more of a rhamnolipid, sophorolipid, trehalolipid or mannosylerythritol lipid (MEL).

[0019] An especially preferred biosurfactant is a sophorolipid. Sophorolipids are biosurfactants produced by several yeast species. In Candida bombicola, the hydrophilic moiety of the biosurfactant molecule is a disaccharide (i.e., sophorose), and the hydrophobic portion is an omega- or (omega- 1)-hydroxy fatty acid attached to the sophorose via a glycosidic bond. The fatty acid chain, most commonly containing 16- and 18-carbon atoms, may be unsaturated and lactonized to the disaccharide. The disclosed potential applications of Sophorolipids include serving as environmentally friendly surfactants in oil recovery, and as active ingredient in detergent, cosmetic and lubricant formulations. Sophorolipids produced by Torulopsis sp. consist of a dimeric sugar (sophorose) and a hydroxyl fatty acid linked by a B-glycosidic bond.

[0020] There are generally considered to be two types of sophorolipids, the acidic (non-lactonic) and the lactonic sophorolipids. The hydroxyl fatty acid moiety of the acidic Sophorolipids forms a macrocyclic lactone ring with the 4”-hydroxyl group of the sophorose by intramolecular esterification. Lactonic Sophorolipids have attracted more attention than their acidic counterparts. The acetylated lactonic Sophorolipids have been applied in cosmetics as antidandruff, bacteriostatic agents and deodorants.

[0021] Sophorolipids may be obtained from Candida apicola, Candida bombicola ATCC 22214, Candida lipolytica and Candida bogoriensis when grown on carbohydrates, hydrocarbons, vegetable oils or their mixtures. They are produced as a mixture of six to eight different hydrophobic sophorosides. Sophorolipids having higher than 50 wt% lactonic sophorolipid preferably 60-80 wt% lactonic sophorolipid are preferred for use in the present invention. A preferred sophorolipid for use in the present invention is Ferma SL from Locus FS. It is said to contain high lactonic sophorolipid content of from 60-80%. It is preferred that the sophorolipid is not a modified sophorolipid.

[0022] Another preferred biosurfactant for use in the present invention is a rhamnolipid. In the case of rhamnolipids, it may comprise one or both components: mono-rhamnolipids having a single rhamnose sugar ring and di-rhamnolipids, having two rhamnose sugar rings. If abbreviations are used R1 is mono-rhamnolipid and R2 is di-rhamnolipid.

[0023] Rhamnolipids may be produced by strains of the bacteria Pseudomonas aeruginosa. A typical mono-rhamnolipid produced by P. aeruginosa is L-rhamnosyl-b-hydroxydecanoyl-b- hydroxydecanoate (RhaCwCw). It may be referred to as Rha-Cw-Cw, with a formula of C26H48O9. Monorhamnolipids have a single rhamnose sugar ring. The IIIPAC Name is 3-[3- [(2R,3R,4R,5R,6S)-3,4,5-trihydroxy-6-methyloxan-2- yl]oxydecanoyloxy]decanoic acid. Di- rhamnolipids have two rhamnose sugar rings. A typical di-rhamnolipid is L-rhamnosyl-L- rhamnosyl-b-hydroxydecanoyl-b-hydroxydecanoate (Rha2CioC ). It may be referred to as Rha- Rha-C- -C-10, with a formula of C32H58O13. The IIIPAC name is 3-[3-[4,5-dihydroxy-6-methyl-3- (3,4, 5-tri hydroxy-6-methyloxan-2- yl)oxyoxan-2-yl]oxydecanoyloxy]decanoic acid.

[0024] Mannosylerythritol lipids (MELs) are a type of biosurfactant produced by certain yeast species, notably from the genus Candida. These compounds are glycolipids composed of a carbohydrate (mannosylerythritol) and a lipid moiety. They have attracted attention due to their potential applications in various industries, including pharmaceuticals, cosmetics, and environmental remediation. These compounds are typically produced through fermentation processes using renewable resources, such as vegetable oils or waste materials, making them environmentally friendly alternatives to traditional surfactants derived from petrochemicals.

[0025] MELs exhibit excellent surfactant properties, including foaming, emulsifying, and detergent activities. Their biodegradability, low toxicity, and stability under various conditions make them attractive alternatives to synthetic surfactants. In addition to their surfactant properties, MELs have shown antitumor, and anti-inflammatory activities, which further broaden their potential applications.

[0026] Trehalose lipids, also known as trehalose esters or trehalose fatty acid esters, are a class of compounds consisting of trehalose molecules linked to fatty acid chains. Trehalose itself is a disaccharide sugar composed of two glucose molecules, and when combined with fatty acids, it forms a glycolipid. These compounds are produced by certain microorganisms, particularly bacteria and fungi, as part of their cell membrane or cell wall structures.

[0027] Trehalose lipids possess surfactant properties, meaning they can reduce surface tension and enhance the stability of emulsions. This makes them useful in various industrial applications, including as emulsifiers, foaming agents, and stabilizers in food, cosmetics, pharmaceuticals, and other products.

[0028] Additionally, trehalose lipids have gained attention for their potential biotechnological applications, such as in bioremediation, biopharmaceuticals, and nanotechnology. Their biocompatibility, low toxicity, and biodegradability make them attractive for use in environmentally friendly products and processes.

[0029] The composition as per the invention preferably comprises biosurfactant in amount of 0.01 to 3 wt%, more preferably 0.025 to 2.5 wt%.

[0030] The composition as per the invention also comprises an anti-microbial peptide (AMP) booster selected from one or more of hydroxystearic acid; nicotinamide; isomer of nicotinamide, cycloalkyl derivatives of nicotinamide, Vitamin A, Vitamin C and linseed oil. An AMP booster as per this invention is meant a compound which when applied on to the skin of a living being (e.g. a human being) produces enhanced levels of AMPs on skin.

[0031] It is preferred that the hydroxy stearic acid is 10-hydroxystearic acid, 12-hydroxystearic acid or trihydoxystearic acid (e.g. 9, 10,13-tri hydroxy stearic acid) or trihydroxy stearin or compounds that yield one or more molecules of hydroxy stearic acid or hydroxystearate on their breakdown like mono, di or tri ester of glycerol with hydroxy stearic acid. Of these, 10-hydroxystearic acid, 12- hydroxystearic acid and 9,10,13-trihydroxystearic acid are more preferred. 12-hydroxystearic acid (12-HSA) is most preferred. 12-HSA has the structure as given below:

[0032] A preferred AMP booster is nicotinamide (which is also known as niacinamide) which is a Vitamin B3 compound. Other vitamin B3 compound which may be used are niacin or nicotinic acid. Isomers of nicotinamide which may be used include isonicotinamide or picolinamide. Cycloalkyl derivatives of nicotinamide which may be used preferably have 4 to 6 carbon atoms in the cycloalkyl group, e.g. are one or more of n-cyclobutyl nicotinamide, n-cyclopentyl nicotinamide, and n-cyclohexyl nicotinamide. The most preferred Vitamin VB3 compound is niacinamide. Niacinamide also known as pyridine-3-carboxamide is the active, water soluble form of vitamin B3.

[0033] Vitamin C or it derivatives may also be used as an AMP booster in the composition of the invention. Vitamin C or its derivative for use may be selected from one or more of ascorbic acid, sodium ascorbyl phosphate, 3-0-ethyl ascorbic acid, ascorbyl methylsilanol pectinate, magnesium ascorbyl phosphate, ascorbyl glucoside, and tetrahexyldecyl ascorbate; preferably ascorbic acid or sodium ascorbyl phosphate. The composition of the present invention comprises a Vitamin A compound as the AMP booster which is also known as a retinoid. Typically, the retinoid is selected from retinyl ester, retinol, retinal, retinoic acid or a mixture thereof. More preferably the retinoid comprises retinol, retinyl ester, or a mixture thereof and even more preferably the retinoid is selected from retinol, retinyl ester, or a mixture thereof. Of these retinyl esters are preferred. Suitable retinyl esters for use in the present invention are retinyl palmitate, retinyl propionate, retinyl acetate, retinyl linoleate, retinyl oleate, or a mixture thereof. Most preferred are retinyl palmitate, retinyl acetate, retinyl propionate, or a mixture thereof. Preferred AMP booster is one or more of hydroxystearic acid; nicotinamide; Vitamin A or Vitamin C, further more preferred being one or both of hydroxystearic acid or nicotinamide.

[0034] The composition of the invention preferably comprises 0.1 % to 5 wt%, more preferably 0.1 to 3 wt% AMP booster.

[0035] Without wishing to be bound by theory the inventors believe that mild surfactants embed itself in the lipid bilayer thereby enabling better activity of the AMPs.

[0036] Thus, it is also possible as per the invention that the composition comprises a biosurfactant comprising a glycolipid; an antimicrobial peptide (AMP) and a cosmetically acceptable vehicle. The AMP for inclusion in such a composition is preferably LL37, Psoriacin, HBD1 , or HBD3, preferably LL37. The AMP so included in the composition may be included in 0.000001 to 0.1 wt% of the composition.

[0037] Leave-on compositions

[0038] The composition of the invention preferably is delivered as a leave on composition. The cosmetically acceptable vehicle for a leave on composition is preferably in the form of an oil, liquid, stick, cream, lotion, spray or gel. The cosmetically acceptable vehicle in leave on compositions preferably includes ingredients like a non-ionic surfactant, a fatty acid, a soap, a polymer, an emollient, a polyhydric alcohol, a solvent, a powder or combinations thereof. Details on the various possible ingredients for inclusion in the cosmetically acceptable vehicle are given below.

[0039] Preferably, the composition comprises a nonionic surfactant. More preferably the nonionic surfactant is selected from those having HLB value in the range 9 to 20. HLB is calculated using the Griffin method wherein HLB = 20 x Mh / M wherein Mh is the molecular mass of the hydrophilic portion of the molecule and M is the molecular mass of the whole molecule, giving a result on an arbitrary scale of 0 to 20. Preferably, the nonionic surfactant having HLB value in the range 9 to 20 is selected from fatty alcohol ethoxylates, alkyl phenol ethoxylates, polyoxyethylene sorbitan alkyl esters and mixtures thereof. Preferably, the leave-on composition comprises 0.5 to 5 wt%, more preferably 1 to 4 wt%, even more preferably from 2 to 3 wt% nonionic surfactant having HLB in the range 9 to 20. Another preferred non-ionic surfactant is cocamide monoethanolamide (CMEA).

[0040] Preferably, the composition of the invention is delivered in the form of a vanishing cream. A vanishing cream is one which when applied and rubbed on to the human skin, vanishes on the skin leaving behind no significant streaks of the composition. Fatty acids when present in a composition along with a soap provides the so-called vanishing cream effect. Preferably, the leave-on composition comprises fatty acids having 10 to 30, more preferably 12 to 25, even more preferably 14 to 20, further more preferably 16 to 18 carbon atoms. Examples of fatty acids that may be used in the composition include pelargonic, lauric, myristic, palmitic, stearic, isostearic, oleic, linoleic, arachidic, behenic, erucic acid and mixtures thereof. Preferably, the fatty acid that may be used is stearic acid or palmitic acid or a mixture thereof. The fatty acid in the present invention is preferably hysteric acid which is substantially (generally about 90 to 95%) a mixture of stearic acid and palmitic acid in a ratio of between 55:45 to 45:55.

[0041] Preferably, the vanishing cream composition comprises from 2.25 to 25 wt%, more preferably from 4 to 22 wt%, even more preferably from 6 to 20 wt%, further more preferably from 8 to 19 wt% and still more preferably from 10 to 18 wt% and yet more preferably from 12 to 16 wt% fatty acid.

[0042] Preferably, the vanishing cream composition comprises soap. Soap, when present in combination with fatty acid in the composition, provides the vanishing effect described above. Preferably, soap in the composition is generally prepared by in-situ neutralization of fatty acid that may be present in the composition. Thus, it is preferred that the soap has a carbon chain length that corresponds to the chain length of fatty acid in the composition. The soap is formed from the fatty acid through use of alkali metal hydroxides e.g. sodium hydroxide or potassium hydroxide. Of the two, potassium hydroxide is more preferred. Thus, the soap is preferably a potassium soap (potassium salt of fatty acid). Preferably, the vanishing cream composition comprises from 0.1 to 10 wt%, more preferably from 0.25% to 8 wt%, even more preferably from 0.5 to 7 wt%, further more preferably from 0.5 to 5 wt% soap, even further more preferably 0.5% to 3%.

[0043] Preferably, the leave on composition may comprise a polymer. The polymer acts as thickener in the composition and improves sensorial properties of the composition. The polymer is preferably selected from the following classes: acrylate I R-methacrylate copolymer e.g. acrylates / steareth-20 methacrylate copolymer (commercially available as Aculyn™ 22) and acrylates / beheneth-25 methacrylate copolymer (commercially available as Aculyn™ 28), acrylate I R-methacrylate crosspolymer e.g. acrylates / steareth-20 methacrylate crosspolymer (commercially available as AculynTM88), acrylates copolymer (commercially available as Aculyn™ 33), acrylate / R-alkyl acrylate crosspolymer e.g. acrylates / C10-C30 alkyl acrylate crosspolymer (commercially available as Pemulen™ TR-2), copolymer of ammonium acryloyldimethyltaurate with vinyl pyrrolidone (commercially available as Aristoflex® AVC), copolymer of sodium acryloyldimethyltaurate with vinyl pyrrolidone (commercially available as Aristoflex® AVS); and crosspolymer of acryloyldimethyltaurate with R-alkyl acrylate and methyacrylate e.g. Ammonium acryloyldimethyltaurate / beheneth-25 methacrylate crosspolymer (commercially available as Aristoflex® HMB and Aristoflex® BLV).

[0044] Preferably, the composition comprises 0.1 to 5 wt%, more preferably 0.25 to 4.5 wt%, even more preferably 0.5 to 4 wt%, further more preferably from 0.75 to 3.5 wt%, still more preferably from 0.75 to 2.75 wt% polymer.

[0045] Preferably, the composition comprises emollients. Examples of emollients that may be used in the leave-on composition include stearyl alcohol, glyceryl monoricinoleate, mink oil, isopropyl isostearate, 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, din-butyl sebacate, isopropyl myristate, 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, isopropyl linoleate, lauryl lactate, myristyl lactate, decyl oleate, myristyl myristate, caprylyl triglyceride and mixtures thereof.

[0046] Preferably the composition may comprise a polyhydric alcohol. Polyhydric alcohols are selected from one or more of glycerol, propylene glycol, dipropylene glycol, polypropylene glycol, polyethylene glycol, sorbitol, hydroxypropyl sorbitol, hexylene glycol, 1 ,3-butylene glycol, isoprene glycol, 1 ,2,6-hexanetriol, ethoxylated glycerol, propoxylated glycerol, or a combination thereof. Most preferred is glycerol.

[0047] Preferably, the composition comprises solvents. Examples of solvents that may be used in the composition include ethyl alcohol, isopropanol, acetone, ethylene glycol ono ethyl ether, diethylene glycol mono butyl ether, diethylene glycol mono ethyl ether and mixtures thereof. Preferably, the composition comprises powders. Examples of powders that may be used in the composition include zinc oxide, titanium oxide, 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 and mixtures thereof.

[0048] Water is present in different amounts depending on the type of leave on composition. Liquid composition may comprise from 40 to 90 wt% water. Creams, lotions and gels may comprise lesser amount of water in the range of 5 to 70 wt% water.

[0049] Preferably, the composition comprises a range of other optional ingredients that include antioxidants, binders, buffering agents, colorants, astringents, fragrance, opacifying agents, conditioners, exfoliating agents, pH adjusters, skin sensates, skin soothing agents, sunscreens, and skin healing agents.

[0050] Wash-off compositions

[0051] The composition of the present invention may also be delivered through a wash off composition which is used for the purpose of cleansing a surface e.g. skin. The composition may then be applied on to the skin using suitable means, often using hands, and alternatively using a sponge, loofah or similar material along with copious amount of water to create lather; which is rinsed off with water to cleanse the surface, e.g. the skin. "Skin" as used herein is meant to include skin on the face and body e.g., neck, chest, back, arms, underarms, hands, legs and scalp.

[0052] The wash off compositions of the invention preferably includes a cleansing surfactant which is defined for the purposes of the present invention as a surfactant other than the biosurfactant claimed. The cleaning surfactant may be one or more of an anionic surfactant, non-ionic or amphoteric surfactant. Anionic surfactant is generally included in 3.0 to 80 wt%, preferably 4.0 to 40 wt%, more preferably 4.0 to 20 wt%. When the wash off composition is in liquid form, it is preferred that the anionic surfactant is a soap, an isethionate, taurate, glycinate, glutamate, alkyl sulphate, a-olefin sulphonate, alkyl ether sulphate, succinate, sulphosuccinate, sarcosinate, amphoacetate, and mixtures thereof.

[0053] Preferably, the anionic surfactant is selected from soap, alkyl sulfates, alkyl ether sulfates, isethionate, taurate and mixtures thereof. Even more preferably, alkyl ether sulfates are used as the anionic surfactant in the composition. Anionic surfactants are known to provide foam and cleansing action.

[0054] Examples of alkyl sulfates that may be used as anionic surfactant in the composition include sodium lauryl sulfate (SLS), sodium myristyl sulfate and mixtures thereof. Examples of AES that may be used as anionic surfactant in the composition include sodium lauryl ether sulfate (SLES), sodium myristyl ether sulfate and sodium palmityl ether sulfate and mixtures thereof. Preferred AES is SLES having 1 to 3 ethylene oxide units per molecule. SLES having 1 to 2 ethylene oxide units per molecule is more preferred.

[0055] Another class of anionic surfactants which is particularly desirable are alkyl isethionate (e.g., fatty acid esters of isethionate acid such as sodium lauroyl or sodium cocoyl isethionate) and alkyl taurate (e.g., alkyl taurate amides such as N-methyl taurate). Especially suitable is to include them as a surfactant mixture as they have the advantage that they are sulfate-free. Further, they offer the ability to formulate isotropic systems at neutral and slightly acidic pH.

[0056] As especially preferred aspect relates to compositions comprising 5 to 20%, preferably 6 to 15% by weight of a surfactant system which comprises (a) alkali metal acyl isethionate, (b) alkali metal alkyl taurate. Preferred isethionate sulfonates include cocoyl isethionate and lauroyl isethionate, preferably having sodium or potassium as counterions. The other preferred anionic surfactant for inclusion in the composition of the invention are alkyl taurates, e.g., alkyl taurate amides. Preferably alkyl taurate amides include sodium methyl cocoyl taurate and sodium methyl lauroyl taurate.

[0057] The composition may also be delivered with soap as the anionic surfactant or as a combination of one or more of the above mentioned synthetic anionic surfactant together with soap. Such combination of soap and synthetic anionic surfactants may be included in a cleansing composition in both liquid as well as in solid (e.g. a bar) compositions. The soap for preparing the cleansing composition of the invention is preferably a C8-C24 soap, more preferably C10-C20 soap and most preferably C12-C18 soap. The cation of the soap can be alkali metal, alkaline earth metal or ammonium. Preferably, the cation of the soap is selected from sodium, potassium or ammonium. More preferably the cation of the soap is sodium or potassium. Fatty acids derived from other suitable oils / fats such as groundnut, soybean, tallow, palm, palm kernel, etc. may also be used in other desired proportions. Such combination of soap with synthetic surfactants is often called a soap-syndet formulation.

[0058] Preferably, the composition may further comprise an amphoteric surfactant. They provide foam boost and improve sensorial of the composition. Preferably, amphoteric surfactants are selected from the class of betaines, sultaines, ethanolamides. Preferred examples are cocamidopropyl betaine (CAPB), cocoamphoacetate and mixtures thereof. When included the composition preferably comprises from 0.1 to 40 wt%, more preferably 1 to 20 wt%, most preferably from 1 to 5 wt% amphoteric surfactant. Non-ionic surfactants may also be included in the wash-off compositions as per the invention. Suitable non-ionic surfactants are the same as those described under the leave-on composition section above.

[0059] The pH of the composition is preferably in the range of 4.0 to 10.5, more preferably 4.0 to 9.0. pH as reported in the present invention is measured as follows. The composition is diluted 1 :1 with deionized water and pH is directly measured by a standard pH meter at room temperature (25°C). The composition of the invention when in the liquid form preferably comprises 5 to 95 wt%, more preferably in 40 to 90 wt% water.

[0060] Preferably, the composition further comprises water soluble / dispersible polymers. They are known to increase the viscosity and stability of liquid cleansing compositions, to enhance in-use and after-use skin sensory feels, and to enhance lather creaminess and lather stability. Such polymers may preferably be used in amounts from 0.1 to 10 wt%, more preferably from 0.1 to 5 wt%.

[0061] Examples of water soluble / or dispersible polymers include the carbohydrate gums such as cellulose gum, microcrystalline cellulose, cellulose gel, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, sodium carboxymethylcellulose, methyl cellulose, ethyl cellulose, guar gum, gum karaya, gum tragacanth, gum arabic, gum acacia, gum agar, xanthan gum and mixtures thereof; modified and nonmodified starch granules and pregelatinized cold water soluble starch; emulsion polymers such as Aculyn® 28, Aculyn® 22 or Carbopol® Aqua SF1 ; cationic polymer such as modified polysaccharides including cationic guar available from Rhone Poulenc under the trade name Jaguar® C13S, Jaguar® C14S, Jaguar® C17, or Jaguar® C16; cationic modified cellulose such as LICARE® Polymer JR 30 or JR 40 from Amerchol; N-Hance® 3000, N-Hance® 3196, N-Hance® GPX 215 or N-Hance® GPX 196 from Hercules; synthetic cationic polymer such as Merquat® 100, Merquat® 280, Merquat® 281 and Merquat® 550 sold by Nalco; cationic starches such as StaLok® 100, 200, 300 and 400 sold by Staley Inc.; cationic galactomannans such as Galactasol® 800 series by Henkel, Inc.; Quadrosoft® LM-200; and Polyquaternium-24®. Also suitable are high molecular weight polyethylene glycols such as Polyox® WSR-205 (PEG 14M), Polyox® WSR-N-60K (PEG 45), and Polyox® WSR-301 (PEG 90M).

[0062] The composition may further comprise emollients. Emollients listed above for use in leave-on compositions may be in wash-off compositions also.

[0063] The compositions may further comprise a wide range of other optional components e.g. antioxidants, biological additives, buffering agents, colorants, astringents, fragrance, humectants, opacifying agents, conditioners, pH adjusters, skin soothing agents and skin healing agents. The composition may also be delivered in solid form in which case it is preferably in the form of a bar. In such cases soap bars are preferred. Soap bars generally have the following constitution. Soap i.e salt of fatty acid is preferably present in an amount of 5 to 80 wt%, preferably from 10 to 75%, more preferably 25 to 75% by weight of the cleansing composition. It may comprise small amount (0.1 to 10 wt%) of synthetic anionic surfactants which could be one or more of the ones listed herein above. The soap bars may include other known ingredients such as perfumes, pigments, preservatives, emollients, gelling agents and thickening agents. Choice of these ingredients will largely depend on the format of the composition. Water is a preferred carrier. When water is present, it is preferably present in at least 1 %, more preferably at least 2%, further more preferably at least 5% by weight of the composition. When water is the carrier, soap bar may comprises 10 to 50%, more preferably 12 to 40%, further more preferably from 12 to 35% by weight water.

[0064] The cleansing composition of the invention may also be delivered through a moisturizing bar composition. Moisturizing bar compositions comprising fatty acyl isethionates (e.g. cocyl isethionate) are especially preferred. Fatty acyl isethionates (e.g., cocoyl isethionates) surfactant "products" are defined as mixtures of anionic acyl isethionate surfactants and fatty acids / fatty acid soaps. They are highly desirable in personal skin or hair cleansing products because they lather well, are mild to the skin and have good emollient properties. Typically, fatty acid isethionate surfactant products are produced by esterification of fatty acids or by reaction of fatty acid chloride having carbon chain length of C8 to C20 with isethionate. A typical surfactant product containing fatty acyl isethionate contains about 40 to 95 wt.% acid isethionate, and 5 to 50 wt.%, typically 10 to 40 wt.% free fatty acid, in addition to isethionate salts, typically at less than 5%, and trace (less than 2 wt.%) of other additives. Fatty acid soap may be included in the range of 5 to 15 wt%. Other surfactants like betaines may be included in 1 to 5 wt%. Water is generally included in 2 to 8 wt% of the composition.

[0065] The composition of the invention may also be delivered through a self-foaming composition. A preferred self-foaming composition comprises 2.5 to 10 wt% surfactant which is usually a mixture of anionic surfactant and amphoteric surfactant. Anionic surfactants preferred are of the amino acid class viz. sodium lauroyl glycinate, sodium cocoyl glycinate, sodium lauroyl glutamate, sodium cocoyl glutamate and may also be selected from one or more of sodium lauroyl isethionate, sodium cocoyl isethionate, alpha olefin sulfonate (AOS), or a combination thereof. The amphoteric surfactant may be one or more as listed herein above. Self foaming composition additionally usually comprises a humectant selected from glycerol, propylene glycol, dipropylene glycol, polypropylene glycol, polyethylene glycol, sorbitol, hydroxypropyl sorbitol, hexylene glycol, 1 ,3-butylene glycol, isoprene glycol, 1 ,2,6-hexanetriol, ethoxylated glycerol, propoxylated glycerol, or a combination thereof. It may also comprise an emollient which may be selected from one or more of the compounds listed herein above. Such types of self-foaming compositions are usually free of sulphate.

[0066] The composition as per the invention may also be delivered through a make-up remover composition. Make-up remover compositions in various forms are known and available like micellar water, lotions, foams, gels, and creams. A preferred make up remover is one which has high amount of oils preferably in the range of 80 to 90 wt%, surfactant (which is preferably nonionic) in the range of 5 to 15 wt%, optionally emollients up to 10 wt% and the rest may be water. The invention also relates to a method of disinfecting an external surface of a human body comprising the step of applying onto the surface a composition of the invention. If the composition is of the wash-off type, it may be rinsed off with copious amounts of water after it is applied.

[0067] The invention also relates to use of a composition of the invention for obtaining an antimicrobial benefit when applied on an external surface of the human body.

[0068] The method and use are preferably non-therapeutic.

[0069] The invention will now be illustrated with the help of the following non-limiting examples:

[0070] Examples

[0071] Examples A-E, 1-4: Effect of combining a Sophorolipid with AMP on antimicrobial efficacy: Actives and their combinations as shown in Table -1 below were taken and the antimicrobial efficacy against microorganisms S. aureus and E. coli were tested using the procedure as given below:

[0072] IN-VITRO MICRODILUTION ASSAY

[0073] Culture preparation

[0074] E.coli and S. aureus was inoculated from glycerol stock to TSA slants. Slants were incubated at 37°C aerobically for 24 hours until saturated growth is seen. These slants were then used to streak TSA agar plates which are then incubated at 37°C for ~16 hrs. This culture was then used for experiments in 3 passages from the main ATCC stock. (Passages include - growing for glycerol stock, making slants and making plates from slants).

[0075] One loopful of this plate culture was dissolved (pipetting and vortexing) in 10mM Sodium Phosphate buffer pH 5.8 (~10ml of buffer). OD was checked and culture was adjusted to 0.6 OD for E.coli and 0.2 for S. aureus at 620 nm. This OD value at 620 nm corresponds to ~108cfu / ml. The culture was then serially diluted to get ~ 106CFU / ml. (0.5ml from 0.8 OD culture was added to 4.5ml buffer (first dilution) and 0.5ml from first dilution added to 4.5ml of buffer (second dilution)

[0076] LL37 PREPARATION

[0077] LL-37 stocks (1 mg / ml) stored in -20°C were taken out (1 tube of 10 pl in this case) and given a short spin after thawing. Working stocks (25pg / ml) were prepared by diluting it in water. This working stock is used for adding to the reaction wells. 0.5 pg / ml and 0.25 pg / ml were the concentrations of LL37 tested in the assay.

[0078] PREPARATION OF ACTIVES

[0079] The stocks of all the respective biosurfactants tested were prepared as mentioned below

[0080] Water soluble actives: 2.5%

[0081] Water insoluble actives (DMSO) - 10% and 2.5%

[0082] The concentrations tested were.

[0083] Water soluble actives - 0.25% and 0.025%

[0084] MEL201 - 0.025%

[0085] ASSAY PROTOCOL

[0086] The test reaction was prepared in a 96 well microtiter plate with duplicate wells for each reaction.

[0087] From the working stock of LL37 15pd and 7.5 J were added to the respective wells for 0.5pg / ml and 0.25 pg / ml test concentrations. Biosurfactants working stocks of 10 and 100 times higher the tested concentrations were prepared and 30 / 3pl of this was added in the respective wells for water soluble actives. Biosurfactants working stock of 100 times higher the tested concentrations was prepared and 3 pl of this was added in the respective wells for water insoluble actives.

[0088] The total volume of the reaction in each well is made up to 300pd with water. Contact time provided was 4 hours at 37° C. Post-incubation, the reactions were plated on pre-prepared TSA agar plates in requisite dilutions. Dilutions were made in D / E neutralizer, in a microtitre plate. (270 pl of D / E + 30 pl reaction mixture, etc.) 100 pl volume of desired dilutions is spread plated onto prepared plates. Plates were incubated aerobically overnight. Colonies were counted at the end of the incubation to quantitate the log kill / survival.

[0089] Table -1 The data in the table above indicates that sophorolipid interacts synergistically with an AMP like LL37 to deliver enhanced antimicrobial efficacy against both a gram positive as well as a gram negative bacteria.

[0090] Examples F-l, 5-6: Effect of combining a MEL surfactant with AMP on antimicrobial efficacy: Actives and their combinations as shown in Table -2 below were taken and the antimicrobial efficacy against microorganisms S. aureus and E. coli were tested using the procedure as given hereinbefore.

[0091] Table - 2 The data in the table -2 above indicates that MEL is also effective in delivering similar synergistic antimicrobial efficacy when combined with AMP.

[0092] Examples J-M, 7-10: Effect of combining a Rhamnolipid with AMP on antimicrobial efficacy: Actives and their combinations as shown in Table -3 below were taken and the antimicrobial efficacy against microorganisms S. aureus and E. coli were tested using the procedure as given hereinbefore.

[0093] Table - 3

[0094] The data in the table -3 above indicates that rhamnolipid is also effective in delivering similar synergistic antimicrobial efficacy when combined with AMP, especially against S. aureus.

Claims

Claims1. A personal care composition comprising(i) A biosurfactant comprising a glycolipid;(ii) 0.05 to 5 wt% an anti-microbial peptide (AMP) booster selected from one or more of hydroxystearic acid; nicotinamide; isomer of nicotinamide, cycloalkyl derivatives of nicotinamide, Vitamin A, Vitamin C and linseed oil; and(iii) a cosmetically acceptable vehicle; wherein said biosurfactant is chosen from one or more of rhamnolipid, sophorolipid, trehalolipid or mannosylerythritol lipid (MEL); and wherein, when the biosurfactant is a sophorolipid, it comprises higher than 50 wt% lactonic sophorolipid.

2. A composition as claimed in claim 1 wherein the biosurfactant is a sophorolipid.

3. A composition as claimed in claim 2 comprising from 60 to 80 wt% lactonic sophorolipid.

4. A composition as claimed in any one of the preceding claims wherein hydroxystearic acid is selected from one or more of 10-hydroxystearic acid, 12-hydroxystearic acid, trihydoxystearic acid or trihydroxy stearin.

5. A composition as claimed in any one of the preceding claims wherein the isomer of niacinamide is selected from one or both of isonicotinamide and picolinamide.

6. A composition as claimed in any one of the preceding claims comprising 0.01 to 3 wt% said biosurfactant.

7. A composition as claimed in any one of the preceding claims comprising 0.1% to 5 wt% AMP booster.

8. A composition as claimed in any one of the preceding claims which is a leave-on composition wherein the cosmetically acceptable vehicle comprises a non-ionic surfactant, a fatty acid, a soap, a polymer, an emollient, a polyhydric alcohol, a solvent, a powder or combinations thereof.

9. A composition as claimed in any one of the preceding claims 1 to 7 which is a skin cleansing composition wherein the cosmetically acceptable vehicle comprises a cleansing surfactant other than said biosurfactant.

10. A composition as claimed in claim 9 wherein said cleansing surfactant is selected from one or more of an anionic, non-ionic or amphoteric surfactant.

11. A personal care composition comprising(i) a biosurfactant comprising a glycolipid;(ii) an anti-microbial peptide (AMP); and(iii) a cosmetically acceptable vehicle.

12. A composition as claimed in claim 11 wherein said AMP is LL37, Psoriacin, HBD1 , HBD3, preferably LL37.

13. A method of disinfecting an external surface of a human body comprising the step of applying onto the surface a composition as claimed in any one of the preceding claims.

14. Use of a composition as claimed in any one of claims 1 to 12 for obtaining an antimicrobial benefit when applied on an external surface of the human body.

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