Anti-dandruff cosmetic composition

Abstract

A cosmetic composition is disclosed comprising i) i) glycine; and ii)a magnesium salt; wherein the molar ratio of said glycine to said magnesium salt is from 1:10 to 4:1; wherein the composition is comprises less than 0.5% of serine by weight of the composition.

Description

[0001] ANTI-DANDRUFF COSMETIC COMPOSITION

[0002] Field of the Invention

[0003] This invention relates to cosmetic compositions, preferably hair care compositions. More particularly the invention relates to cosmetic compositions that comprise glycine and a magnesium salt and has a limited amount of serine.

[0004] Background of the Invention

[0005] Dandruff control is an important aspect of hair cleansing and care. Anti-dandruff benefit has been provided through hair care compositions including shampoos and hair conditioners. Dandruff is an issue that affects many people globally. The condition is manifested by the shedding of clumps of dead skin cells from the scalp. These are white in colour and provide an aesthetically displeasing appearance. A factor that contributes to dandruff is certain members of the Malassezia yeasts. To combat these, anti-dandruff products have included certain antidandruff agents which have anti-fungal activity, for example, piroctone compound such as piroctone olamine. These anti-dandruff agents remove (or at least reduce the level of) the Malassezia from the scalp and provide moderately effective treatment of the dandruff condition. Such a product performs as a hair cleansing shampoo or as a hair conditioner while mitigating the causes of dandruff.

[0006] There remains a need to provide an improved antimicrobial efficacy onto the surface of skin preferably scalp, upon applying the products.

[0007] The present inventors have now found unexpectedly that the combination of glycine and a magnesium salt with certain ratio when present in the composition which does not comprise serine in a concentration more than a limited amount can provide synergistic antimicrobial efficacy onto a topical surface of a human or animal body, preferably on skin preferably scalp.

[0008] Summary of the Invention

[0009] In a first aspect, the present invention is directed to a cosmetic composition comprising: i) glycine; and ii) a magnesium salt; wherein the molar ratio of said glycine to said magnesium salt is from 1 :10 to 4:1 ; wherein the composition comprises less than 0.5% of serine by weight of the composition. In a second aspect, the present invention is directed to use ofa cosmetic composition of the first aspect for providing synergistic antimicrobial benefit on a topical surface of a human or animal body.

[0010] In a third aspect, the present invention is directed to use of a cosmetic composition of the first aspect for against at least some Malassezia spp. on a topical surface of a human or animal body.

[0011] In a fourth aspect, the present invention is directed to use of a cosmetic composition of the first aspect for preventing or alleviating the symptoms of dandruff on the scalp or hair.

[0012] In a fifth aspect, the present invention is directed to a non-therapeutic method of preventing or alleviating the symptoms of dandruff on the scalp or hair comprising a step of applying a safe and effective amount of a cosmetic composition of the first aspect.

[0013] All other aspects of the present invention will more readily become apparent upon considering the detailed description and examples which follow.

[0014] Detailed Description of the Invention

[0015] Cosmetic Composition

[0016] By ‘a cosmetic composition’ as used herein, is meant to include a composition for topical application to skin, hair and / or scalp of mammals, especially human beings. Such a composition is generally applied on to the desired topical surface of the body for a period of time from a few seconds to up to 24 hours. When the period of time of application is low say of the order of a few seconds to a few minutes after which the composition is rinsed off with water or wiped away, such a composition is known as a cleansing composition or a wash-off composition. On the other hand, When the composition is applied for longer period of time say from several minutes to up to 24 hours and washed off usually during the process of normal personal cleaning, such a composition is known as a leave-on composition. The composition as per the present invention includes any product applied to a human body for also improving appearance, cleansing, odor control or general aesthetics.

[0017] Hair Care Composition

[0018] “Hair care composition”, as used herein, is meant to include a composition for topical application to hair and / or scalp of mammals, especially humans. 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 appearance, cleansing, odor control or general aesthetics. The composition of the present invention can be in the form of a liquid, lotion, cream, foam, scrub, gel, or bar. Non-limiting examples of such compositions include leave-on hair lotions, creams, and rinse-off shampoos, conditioners, shower gels, or toilet bar. The composition of the present invention is preferably a rinse-off composition, especially preferred being a shampoo or a conditioner and most preferably a shampoo.

[0019] Miscellaneous

[0020] Except in the 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 may optionally be understood as modified by the word “about”.

[0021] All amounts are by weight of the final hair care composition, unless otherwise specified.

[0022] It should be noted that in specifying any ranges of values, any particular upper value can be associated with any particular lower value.

[0023] For the avoidance of doubt, 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.

[0024] The disclosure of the invention as found herein is to be considered to cover all embodiments as found in the claims as being multiply dependent upon each other irrespective of the fact that claims may be found without multiple dependency or redundancy.

[0025] Where a feature is disclosed with respect to a particular aspect of the invention (for example a composition of the invention), such disclosure is also to be considered to apply to any other aspect of the invention (for example a method of the invention) mutatis mutandis.

[0026] Glycine is an amino acid which is essential in the production of collagen, a protein that gives structure to bones, skin, muscles, and connective tissues. It is the simplest stable amino acid, with the chemical formula NH2-CH2-COOH. It may be D-glycine and L-Glycine, or a mixture thereof, preferably it is D-glycine. Amount of the glycine in the composition of the invention would depend on the type of the cosmetic composition and the precise nature of other antimicrobial agents used. It is preferred that the composition comprises from 0.01 to 10% of glycine, preferably from 0.1 to 5%, more preferably from 0.5 to 5%, furthermore preferably from 1 to 3% by weight of the composition.

[0027] Magnesium salt

[0028] Magnesium salt in accordance with this invention may be selected from a group consisting of magnesium oxide, magnesium carboxylates, magnesium halids, magnesium sulphate, magnesium nitrate, magnesium carbonate, magnesium carbonate hydroxide, magnesium hydroxide, magnesium amino acid complex, magnesium silicates, magnesium phosphate, preferably selected from a group consisting of magnesium oxide, magnesium carboxylates, magnesium halids, magnesium sulphate, magnesium nitrate, magnesium carbonate, magnesium carbonate hydroxide, magnesium hydroxide, magnesium amino acid complex, magnesium silicates, magnesium phosphate.

[0029] It is preferred that the magnesium salt in accordance with this invention is selected from a group consisting of slightly water-soluble magnesium salt and water-soluble magnesium salt, more preferably is water-soluble magnesium salt. The term “water-soluble”, as used herein, means a salt that has a solubility in water at 20 °C and 1 atm of greater than 1 g salt / 100 ml water.

[0030] “Water-insoluble” means a salt that has a solubility in water at 20 °C and 1 atm of less than 0.01 g salt / 100 ml water. Therefore “slightly water-soluble” means a salt that has a solubility in water at 20 °C and 1 atm of from 0.01 to 1 g / 100 ml.

[0031] It is preferred that the magnesium salt is selected from a group consisting of magnesium carboxylates, magnesium halids, magnesium sulphate, magnesium nitrate, magnesium amino acid complex, more preferably selected from a group consisting of magnesium carboxylates, magnesium halids, magnesium sulphate, magnesium nitrate.

[0032] Suitable magnesium carboxylates may include lactate, citrate, ascorbate, acetate, gluconate, laurate, myristate, palmitate, salicylate, aspirinate, stearate, succinate, tartrate, undecylenate, neodecanoate and ricinoleate, preferably include lactate, citrate, acetate, gluconate, salicylate, succinate, ricinoleate.

[0033] Suitable magnesium halids include magnesium chloride, magnesium bromide and magnesium iodide. Magnesium amino acid complex is preferably magnesium glycinate.

[0034] It is preferred that the magnesium salt is selected from a group consisting of magnesium chloride, magnesium bromide, magnesium iodide, magnesium nitrate, magnesium sulfate, magnesium salicylate, magnesium lactate, magnesium acetate, magnesium succinate, magnesium ricinoleate, magnesium glycinate, magnesium gluconate, and magnesium citrate, more preferably is selected from a group consisting of magnesium chloride, magnesium sulfate, magnesium salicylate, magnesium glycinate, magnesium gluconate, and magnesium citrate, more preferably selected from a group consisting of magnesium chloride, magnesium sulfate, magnesium salicylate, magnesium gluconate, and magnesium citrate, further more preferably selected from magnesium chloride, magnesium sulfate and mixture thereof .

[0035] It is preferred that the composition comprises from 0.01 to 10% of the magnesium salt, preferably from 0.1 to 10%, more preferably 0.5 to 8%, furthermore preferably 1 to 5% by weight of the composition.

[0036] In the composition in accordance with the invention, the molar ratio of the glycine to magnesium salt is from 1:10 to 4:1 , preferably from 1:5 to 4:1 , more preferably from 1:4 to 3:1 , more preferably from 1 :3.7 to 2.71:1.

[0037] The composition in accordance with the invention comprises less than 0.5% of serine by weight of the composition, preferably serine is present in an amount less than 0.3%, preferably less than 0.1%, more preferably less than 0.05%, furthermore preferably less than 0.01% and most preferably absent in the composition, by weight of the composition.

[0038] The sum of the fractional inhibitory concentrations (£FIC) is widely used in the context of combinations of antimicrobial ingredients. It is a tool to determine whether the antimicrobial ingredients (when used in combination) have synergistic effect or antagonistic effect or neither of the two, i.e. , an additive effect. The present inventors have resorted to the FIC test to evaluate the combined effect of glycine with magnesium salt against M. restricta.

[0039] It is believed that while the glycine and magnesium salt according to the present invention present in the compositions of the invention, the magnesium salt interacts synergistically with the glycine to make it even more efficacious. Cosmetic composition

[0040] The composition of the invention preferably comprises a cosmetically acceptable carrier. The cosmetically acceptable carrier is such that the composition can be prepared, e.g., as a shampoo, conditioner, body wash, hand wash or face wash product, cream, lotion, gel, powder, ointment, deodorant, hand sanitiser or a soap bar and the rest of the ingredients would vary accordingly. It is preferred that the cosmetically acceptable carrier comprises water.

[0041] The hair care composition may comprise a scalp health agent to provide scalp benefits. This group of materials is varied and provides a wide range of benefits including moisturization, barrier improvement, anti-fungal, anti-microbial and anti-oxidant, anti-itch, sensates, and antidandruff, etc.

[0042] The anti-dandruff agents can be selected from pyridinethione salts, zinc pyrithione, copper pyrithione, coal tar, sulfur, charcoal, zinc carbonate, hydroxy pyridines such as piroctone olamine, azoles such as ketoconazole or climbazole, selenium sulfide, hinokitiol, salicylic acid, and mixtures thereof.

[0043] The anti-microbial active can be selected from a group consisting of zinc pyrithione, copper pyrithione, sulfur, zinc carbonate, selenium sulfide, hinokitiol, hydroxamic acid such as caprylhydroxamic acid and benzohydroxamic acid, triclosan, whitfield's ointment, castellani's paint, aluminium chloride, gentian violet, hydroxyl pyridine and wherein the hydroxyl pyridine may be piroctone olamine, ciclopirox olamine, rilopirox, MEA-Hydroxyoctyloxypyridinone, strobilurins such as azoxystrobin and metal chelators such as 1 ,10-phenanthroline, potassium permanganate, sodium thiosulfate, propylene glycol, oil of bitter orange, urea preparations, griseofulvin, 8-hydroxyquinoline ciloquinol, thiobendazole, thiocarbamates, haloprogin, polyenes, hydroxypyridone, morpholine, benzylamine, allylamines (such as terbinafine), tea tree oil, clove leaf oil, coriander, palmarosa, berberine, thyme red, cinnamon oil, rosemary oil, cinnamic aldehyde, citronellic acid, ichthyol pale, Sensiva SC-50, Elestab HP-100, azelaic acid, lyticase, iodopropynyl butylcarbamate (IPBC), isothiazalinones such as octyl isothiazalinone, azoles such as ketoconazole or climbazole, benzimidazole, benzothiazole, bifonazole, butaconazole nitrate, clotrimazole, croconazole, eberconazole, econazole, elubiol, fenticonazole, fluconazole, flutimazole, isoconazole, lanoconazole, metronidazole, miconazole, neticonazole, omoconazole, oxiconazole nitrate, sertaconazole, sulconazole nitrate, tioconazole, thiazole, triazoles such as terconazole and itraconazole and mixtures thereof. Other scalp health agents may include but are not limited to: niacinamide, glycerin, glycine, alanine, vitamin E and F, caffeine, panthenol, glycols, glycolic acid, PCA, PEGs, erythritol, lactates, hyaluronates, allantoin and other ureas, betaines, sorbitol, glutamates, xylitols, menthol, menthyl lactate, iso cyclomone, benzyl alcohol, natural extracts / oils including peppermint, spearmint, argan, jojoba and aloe.

[0044] The hair care composition may comprise from 0.01 to 10%, preferably from 0.1 to 5%, more preferably from 0.5 to 2% of the scalp health agent by weight of the composition.

[0045] The composition may comprise a scalp health agent selected from a group consisting of salicylic acid, piroctone compound, hinokitiol, azole compound including climbazole and ketoconazole, selenium sulfide.

[0046] The composition may also additionally comprise an antimicrobial agent.

[0047] It is preferred that the composition is a rinse-off or leave-on product, more preferably a hair care composition. Preferably the composition is a leave-on composition. Alternatively, the composition is preferably a rinse-off composition.

[0048] When the composition is a rinse-off composition, it is preferred that the composition comprises a cleansing surfactant. The composition of this invention preferably comprises a cleansing surfactant comprising an anionic surfactant.

[0049] Non-limiting examples of suitable anionic surfactants are alkyl sulphates, alkyl ether sulphates, alkaryl sulphonates, alkanoyl isethionates, alkyl succinates, alkyl sulphosuccinates, alkyl ether sulphosuccinates, N-alkyl sarcosinates, alkyl phosphates, alkyl ether phosphates, and alkyl ether carboxylic acids and salts thereof, especially their sodium, magnesium, ammonium and mono-, di- and triethanolamine salts. The alkyl and acyl groups generally contain from 8 to 18, preferably from 10 to 16 carbon atoms and may be unsaturated. The alkyl ether sulphates, alkyl ether sulphosuccinates, alkyl ether phosphates and alkyl ether carboxylic acids and salts thereof may contain from 1 to 20 ethylene oxide or propylene oxide units per molecule. Typical anionic surfactants for use in compositions of the invention include, but not limited to, sodium oleyl succinate, ammonium lauryl sulphosuccinate, sodium lauryl sulphate, sodium lauryl ether sulphate, sodium lauryl ether sulphosuccinate, ammonium lauryl sulphate, sodium dodecylbenzene sulphonate, triethanolamine dodecylbenzene sulphonate, sodium cocoyl isethionate, sodium lauryl isethionate, lauryl ether carboxylic acid, sodium N-lauryl sarcosinate or mixtures thereof.

[0050] Preferred anionic surfactants are the alkyl sulphates and alkyl ether sulphates. Preferred alkyl sulphates are C8-18 alky sulphates, more preferably C12-18 alkyl sulphates, preferably in the form of a salt with a solubilising cation such as sodium, potassium, ammonium or substituted ammonium. Examples are sodium lauryl sulphate (SLS) or sodium dodecyl sulphate (SDS). It is particularly preferred that the anionic surfactant is alkyl ether sulphate. Preferred alkyl ether sulphates are those having the formula: RO(CH2CH2O)nSO-,3M; wherein R is an alkyl or alkenyl having from 8 to 18 (preferably 12 to 18) carbon atoms; n is a number having an average value of greater than at least 0.5, preferably between 1 and 3, more preferably between 1 and 2; and M is a solubilising cation such as sodium, potassium, ammonium or substituted ammonium. An example is sodium lauryl ether sulphate (SLES). Preferred alkyl ether sulphate is sodium lauryl ether sulphate having an average degree of ethoxylation of from 0.5 to 3, preferably from 1 to 3, more preferably from 1 to 2.

[0051] It is preferred that the anionic surfactant is an ethoxylated alkyl sulphate a degree of ethoxylation of less than 3, preferably an ethoxylated alkyl sulphate a degree of ethoxylation of less than 2, more preferably sodium laureth sulphate (1 EO).

[0052] Alternatively, it is preferred that the surfactant is sulfate-free.

[0053] The composition may comprise an alpha olefin sulfonate anionic surfactant of general formula (I):

[0054] RI-CH=CH-CH2-SO3-M+(I) in which Ri is selected from linear or branched alkyl groups having from 11 to 13 carbon atoms and mixtures thereof; and M is a solubilizing cation;

[0055] Preferably Ri in general formula (I) is a C14 or C16 linear alkyl group.

[0056] Preferably M in general formula (I) is selected from alkali metal cations (such as sodium or potassium), ammonium cations and substituted ammonium cations (such as alkylammonium, alkanolammonium or glucammonium). Commercially produced alpha olefin sulfonate anionic surfactants of general formula (I) may be made by sulfating C14-16 olefins derived from natural gas. The process can also yield mixtures of homologues and low levels of unreacted olefins.

[0057] Particularly preferred is alpha olefin sulfonate with an average of 14-16 carbons. A suitable example of such a material is Bioterge AS40 (ex Stepan).

[0058] The amount of alpha olefin sulfonate anionic surfactant, at 100 % activity, of general formula (I) ranges from 3 to 13 %, preferably from 3.5 to 12%, more preferably from 3 to 10%, (by weight based on the total weight of the composition).

[0059] The composition may comprise an amphoteric or zwitterionic surfactant, selected from an alkyl betaine of general formula (II)

[0060] R2-N+(CH3)2-CH2-COO- M+(II) wherein R2= C12 (Lauryl) or Coco derived; an alkyl hydroxy sultaine of general formula (III),

[0061] R3-N+(CH3)2-CH2-CH(OH)-CH2-SO3- M+(III) wherein R3= C12 (Lauryl) or Coco derived; an alkyl aminopropyl hydroxy sultaine of general formula (IV),

[0062] R4-CO-NH-(CH2)3-N+(CH3)2-CH2-CH(OH)-CH2-SO3- M+(IV) wherein R4= C12 (Lauryl) or Coco derived; an alkyl amphoacetate of general formula (V),

[0063] R5-CO-NH-(CH2)2-N(CH2-CH2-OH)(CH2-COO- M+) (V) wherein Rs = C12 (Lauryl) or Coco derived; and mixtures thereof.

[0064] The preferred surfactant (ii) is selected from coco betaine, lauryl hydroxy sultaine, coco aminopropyl hydroxy sultaine, lauryl amphoacetate and mixtures thereof, most preferably selected from coco betaine, lauryl hydroxy sultaine and mixtures thereof. Alkyl hydroxy sultaines are preferred, particularly lauryl hydroxy sultaine.

[0065] The amount of amphoteric or zwitterionic surfactants of general formula (II), (III), (IV) or (V) or mixtures thereof, preferably ranges from 1 to 6%, more preferably from 1.5 to 5%, most preferably from 2 to 3.5 % (based on the total weight of the composition and 100 % activity).

[0066] The amphoteric or zwitterionic surfactant is preferably selected from a betaine amphoteric surfactant of general formula (II), which is coco betaine, an amphoteric surfactant of general formula (III), which is lauryl hydroxy sultaine, and mixtures thereof, in an amount of from 1 to 4 % (by weight based on the total weight of the composition and 100 % activity).

[0067] The combined amount of (i) and (ii) ranges from 4 to 20 wt %, preferably from 5 to 17 wt %, most preferably from 8 to 15 wt % (based on the total weight of the composition and 100 % activity).

[0068] The composition may comprise alpha olefin sulfonate in an amount ranging from 3.25 to 8% (by weight based on the total weight of the composition and 100 % active material); and an amphoteric or zwitterionic surfactant selected from coco betaine, lauryl hydroxy sultaine, coco aminopropyl hydroxy sultaine, lauryl amphoacetate or mixtures thereof, in an amount ranging from 1 to 4 % by weight of the composition.

[0069] The weight ratio of the alpha olefin sulfonate anionic surfactant to the amphoteric surfactant may range from 1 :1 to 6:1 , preferably from 1.5:1 to 5.

[0070] The anionic surfactants are typically present in the composition of the present invention at a level of from 0.5 to 20%, more preferably from 2 to 16% and most preferably from 3 to 16%, by weight of the composition.

[0071] Suitable amphoteric surfactant examples include alkyl amine oxides, alkyl betaines, alkyl amidopropyl betaines, alkyl sulphobetaines (sultaines), alkyl amphoacetates, alkyl amphopropionates, alkyl amidopropyl hydroxysultaines, wherein the alkyl group has from 8 to 19 carbon atoms.

[0072] Preferably, the amphoteric surfactant is a betaine surfactant. It is preferred that the betaine surfactant is one of alkyl amidopropyl betaines. Cocamidopropyl betaine (CAPB) is particularly preferred.

[0073] In a preferred embodiment, the composition comprises from 0.1 to 10 wt.%, preferably from 0.5 to 8 wt.%, more preferably from 1 to 5 wt.% of an amphoteric surfactant by weight of the composition.

[0074] The ratio of ethoxylated anionic surfactant to amphoteric surfactant in which the ratio of anionic surfactant to amphoteric surfactant is less than 10:1, preferably from 2:1 to 10:1, more preferably from 3:1 to 9:1.

[0075] The total amount of cleansing surfactant in the composition for use in the invention is generally from 3 to 35 wt%, preferably from 5 to 25 wt%, most preferably from 7 to 16 wt% of the total composition.

[0076] When the composition is a leave-on composition, the composition may comprise a non-ionic surfactant, in an amount from 0.1 to 20% by weight of the composition, preferably from 0.4 to 15%, more preferably from 0.5 to 10% by weight of the composition. The non-ionic surfactant can be one fatty alcohol ethoxylate or polyethoxylated monoester. The fatty alcohol ethoxylate can be one of C12-C18 fatty alcohol ethoxylates. The polyethoxylated monoester can be selected from a group consisting of polysorbate 21, polysorbate 60, polysorbate 80, polysorbate 40, polysorbate 20.

[0077] Typically leave-on compositions are substantially free from cleansing surfactants. Thus it is preferred that the composition comprises less than 1 wt% cleansing surfactant, more preferably less than 0.5 wt%, more preferably still less than 0.1% and most preferably from 0 to 0.01 wt%. Cleansing surfactants are typically anionic surfactants such as, for example, alkyl sulfates and / or alkyl ether sulfates. The leave-on composition may comprise a moisturizing agent. Preferably the moisturizing agent is selected from the group consisting of 1 ,2-glycols, selected from caprylyl glycol, pentylene glycol, 1,2-hexanediol and C15-18 glycol.

[0078] The leave-on composition may also comprise a thickening agent. The thickening agent may be a polymer, a cellulose, a xanthan gum, a gelatin.

[0079] Hair care composition

[0080] Preferably the composition is a shampoo, hair conditioner, hair cream, hair gel, hair serum, mousse or hair oil.

[0081] In a preferred embodiment, the hair care composition is rinse-off composition, particularly a shampoo. Shampoo compositions for use in the invention are generally aqueous, i.e. they have water or an aqueous solution or a lyotropic liquid crystalline phase as their major component. Suitably, the shampoo composition will comprise from 50 to 98%, preferably from 60 to 92% water by weight based on the total weight of the composition. Such compositions are referred to as having an aqueous base.

[0082] The hair care composition may additionally comprise a conditioning agent to provide conditioning benefit. Preferably, the hair care composition comprises discrete dispersed droplets of a water-insoluble conditioning agent, which has a mean droplet diameter (D3,2) of less than 15 microns, preferably less than 10 microns, more preferably less than 5 microns, most preferably less than 3 microns. The mean droplet diameter (D3,2) of a water-insoluble conditioning agent may be measured by means of a laser light scattering technique, for example using a 2600D Particle Sizer from Malvern Instruments.

[0083] The water-insoluble conditioning agent may include non-silicone conditioning agent comprising non-silicone oily or fatty materials such as hydrocarbon oils, fatty esters and mixtures thereof. Preferably, the water-insoluble conditioning agent is emulsified silicone oil.

[0084] Suitable silicones include polydiorganosiloxanes, in particular polydimethylsiloxanes which have the CTFA designation dimethicone. Also suitable for use in compositions of this invention (particularly shampoos and conditioners) are polydimethyl siloxanes having hydroxyl end groups, which have the CTFA designation dimethiconol. Also suitable for use in compositions of this invention are silicone gums having a slight degree of cross-linking, as are described for example in WO 96 / 31188. Preferably, the silicone oil comprises dimethicone, dimethiconol or a mixture thereof.

[0085] Suitable emulsified silicones for use in the hair care compositions of this invention are available as pre-formed silicone emulsions from suppliers of silicones such as Dow Corning and GE silicones. The use of such pre-formed silicone emulsion is preferred for ease of processing and control of silicone particle size. Such pre-formed silicone emulsions will typically additionally comprise a suitable emulsifier, and may be prepared by a chemical emulsification process such as emulsion polymerisation, or by mechanical emulsification using a high shear mixer. Examples of suitable pre-formed silicone emulsions include DC1785, DC1788, DC7128, all available from Dow Corning. These are emulsions of dimethiconol / dimethicone.

[0086] Another class of silicones which may be used are functionalized silicones such as amino functional silicones, meaning a silicone containing at least one primary, secondary or tertiary amine group, or a quaternary ammonium group. Examples of suitable amino functional silicones include polysiloxanes having the CTFA designation “amodimethicone.”

[0087] The water-insoluble conditioning agent is generally present in hair care composition of this invention in an amount from 0.05 to 15%, preferably from 0.1 to 10%, more preferably from 0.5 to 8%, most preferably from 1 to 5%, based on total weight of the hair care composition.

[0088] Preferably the composition of the invention further comprises a suspending agent. Suitable suspending agents are selected from polyacrylic acids, cross-linked polymers of acrylic acid, copolymers of acrylic acid with a hydrophobic monomer, copolymers of carboxylic acidcontaining monomers and acrylic esters, cross-linked copolymers of acrylic acid and acrylate esters, heteropolysaccharide gums and crystalline long chain acyl derivatives. The long chain acyl derivative is desirably selected from ethylene glycol stearate, alkanolamides of fatty acids having from 16 to 22 carbon atoms and mixtures thereof. Ethylene glycol distearate and polyethylene glycol 3 distearate are preferred long chain acyl derivatives, since these impart pearlescence to the composition. Polyacrylic acid is available commercially as Carbopol 420, Carbopol 488 or Carbopol 493. Polymers of acrylic acid cross-linked with a polyfunctional agent may also be used; they are available commercially as Carbopol 910, Carbopol 934, Carbopol 941 and Carbopol 980. An example of a suitable copolymer of a carboxylic acid containing monomer and acrylic acid esters is Carbopol 1342. All Carbopol (trademark) materials are available from Goodrich. Suitable cross-linked polymers of acrylic acid and acrylate esters are Pemulen TR1 or Pemulen TR2. A suitable heteropolysaccharide gum is xanthan gum, for example that available as Kelzan mu.

[0089] Mixtures of any of the above suspending agents may be used. Preferred is a mixture of crosslinked polymer of acrylic acid and crystalline long chain acyl derivative.

[0090] The suspending agent is generally present in hair care composition of this invention in an amount of from 0.1 to 10%, more preferably from 0.2 to 6%, and most preferably from 0.3 to 4%, based on total weight of the hair care composition and including all ranges subsumed therein.

[0091] Preservatives may also be incorporated into the hair care composition of this invention to protect against the growth of potentially harmful microorganisms. Suitable traditional preservatives include alkyl esters of parahydroxybenzoic acid, hydantoin derivatives, propionate salts, and a variety of quaternary ammonium compounds. Illustrative yet non-limiting examples of the types of preservatives that may be used in this invention include, for examples, phenoxyethanol, sodium salicylate, methyl paraben, butyl paraben, propyl paraben, diazolidinyl urea, sodium dehydroacetate, benzyl alcohol, sodium benzoate, iodopropynyl butylcarbamate, caprylyl glycol, disodium EDTA or mixtures thereof. In an especially preferred embodiment, the preservative is sodium benzoate, phenoxyethanol, sodium salicylate or a mixture thereof. Preservatives are preferably employed in amounts ranging from 0.01 to 2% by weight of the hair care composition.

[0092] It is further preferred that the hair care composition of the invention comprises a cosmetic ingredient. Preferably the cosmetic ingredient is selected from the group consisting of a silicone, an antibacterial agent other than antidandruff agents, a foam booster, a perfume, encapsulates (for example encapsulated fragrance) a dye, a colouring agent, a pigment, a preservative, a thickener, a protein, a phosphate ester, a buffering agent, a pH adjusting agent, a pearlescer (for example; mica, titanium dioxide, titanium dioxide coated mica, ethylene glycol distearate (INCI glycol distearate)) and / or opacifier, a viscosity modifier, an emollient, a sunscreen, an emulsifier, a sensate active (for example menthol and menthol derivatives), vitamins, mineral oils, essential oils, lipids, natural actives, glycerin, natural hair nutrients such as botanical extracts, fruit extracts, sugar derivatives and amino acids, microcrystalline cellulose and mixtures thereof. Preferably, the composition of the present invention includes from 0.01 to 20 wt% of the at least one cosmetic ingredient, more preferably from 0.05 to 10 wt%, still more preferably from 0.075 to 7.5 wt% and most preferably, from 0.1 to 5 wt% of the at least one cosmetic ingredient, by weight of the total composition.

[0093] As an alternative, the cosmetic composition of the invention is a hair conditioner. When conditioning benefits are to be delivered through the composition of the invention the composition is called a hair conditioner. Typically, the most popular conditioning agents used in hair care compositions are water-insoluble oily materials such as mineral oils, naturally occurring oils such as triglycerides and silicone polymers. Conditioning benefit is achieved by the oily material being deposited onto the hair resulting in the formation of a film, which makes the hair easier to comb when wet and more manageable when dry. An especially useful conditioning agent is a silicone, preferably a non-volatile silicone. Advantageously compositions herein may include one or more silicones. The silicones are conditioning agents found in dispersed or suspended particulate form. They are intended to deposit onto hair remaining behind after rinsing of the hair with water. Suitable silicone oils may include polyalkyl siloxanes, polyaryl siloxanes, polyalkylaryl siloxanes, polyether siloxane copolymers and mixtures thereof. Amino silicones are often formulated with shampoo compositions. Amino silicones are silicones containing at least one primary amine, secondary amine, tertiary amine or a quaternary ammonium group. High molecular weight silicone gums can also be utilized. Another useful type are the crosslinked silicone elastomers such as Dimethicone / Vinyl / Dimethicone Crosspolymers (e.g. Dow Corning 9040 and 9041).

[0094] It is preferred that hair conditioner composition of the invention comprises 0.1 to 10 wt%, more preferably from about 0.1 to about 8 wt% silicone. Alternatively, the hair conditioner is silicone-free, containing not more than 1 wt% silicone. It is preferred that pH of the composition is more than 4.0, more preferably 5.0 to 7.0.

[0095] Hair conditioner composition of the invention preferably may also comprise 0.5 to 10 wt% fatty alcohol. The combined use of fatty alcohols and cationic surfactants in conditioning compositions is believed to be especially advantageous, because this leads to the formation of a lamellar phase, in which the cationic surfactant is dispersed.

[0096] Representative fatty alcohols comprise from 8 to 22 carbon atoms, more preferably 16 to 22.

[0097] Fatty alcohols are typically compounds containing straight chain alkyl groups. Examples of suitable fatty alcohols include cetyl alcohol, stearyl alcohol and mixtures thereof. The use of these materials is also advantageous in that they contribute to the overall conditioning properties of compositions of the invention.

[0098] Method and Use

[0099] The present invention provides for use of a cosmetic composition of the first aspect for providing synergistic antimicrobial benefit on a topical surface of a human or animal body, preferably on skin, more preferably on scalp. Preferably such use is non-therapeutic, it is for cosmetic purpose.

[0100] The present invention provides for use of a cosmetic composition of the first aspect for against at least some Malassezia spp. on a topical surface of a human or animal body, preferably on skin, more preferably on scalp. Preferably the cosmetic composition is an antidandruff composition effective against at least some Malessezia spp. on a topical surface of a human or animal body, preferably on scalp. Preferably the Malessezia spp. is Malessezia restricta. Preferably such use is non-therapeutic, it is for cosmetic purpose.

[0101] The present invention provides for use of a cosmetic composition of the first aspect for preventing or alleviating the symptoms of dandruff on the scalp or hair. Preferably such use is non-therapeutic, it is for cosmetic purpose.

[0102] The present invention provides for a non-therapeutic method of providing synergistic antimicrobial benefit on a topical surface of a human or animal body comprising a step of applying a safe and effective amount of a cosmetic composition of the first aspect. Preferably the topical surface is skin, more preferably is scalp. It also provides for a non-therapeutic method of preventing or alleviating the symptoms of dandruff on the scalp or hair. Preferably it is for cosmetic purpose. The term safe an effective amount is well known to persons skilled in the art and such amounts may vary depending on the product format, for example, the said amount in the case of a leave on composition could be 1 to 2 ml for each application, while the same amount could be 5 to 10 ml for each application in the case of shampoos. The method may be utilized for preventing or treating acne, dandruff or for maintaining general hygiene. Mode of Use

[0103] The compositions of the invention are primarily intended for topical application to scalp and / or at least a portion of the hair or skin of an individual, either in rinse-off or leave-on compositions.

[0104] When the composition is a shampoo, it is topically applied to the hair and then massaged into the hair and scalp. Then it is rinsed with water prior to drying the hair.

[0105] The invention will be further illustrated by the following, non-limiting Examples, in which all percentages quoted are by weight based on total weight unless otherwise stated.

[0106] The examples are intended to illustrate the invention and are not intended to limit the invention to those examples perse.

[0107] Example 1

[0108] The antimicrobial efficacy of exemplary compositions according to the invention was determined as against M. restricta.

[0109] The concerned procedures will now be briefly explained.

[0110] Method 1 : TFIC assay against M. restricta.

[0111] M. restricta (CBS 7877) was maintained on Modified Leeming & Notman Agar (MLNA) agar (Solution A) plate and then cultured into 20ml of growth medium Modified Leeming & Notman broth (MLNB, Solution B).

[0112] Solution A

[0113] Modified Leeming & Notman Agar (MLNA)

[0114] 10g Bacteriological Peptone

[0115] 10g Glucose 2g Yeast Extract

[0116] 8g Ox bile

[0117] 10ml Glycerol

[0118] 0.5g Glycerol Monostearate

[0119] 5ml Tween 60

[0120] 20ml Olive oil

[0121] 15g Agar No.1

[0122] Deionized Water to 1000ml

[0123] (Ensure stirring thoroughly including after autoclaving)

[0124] Solution B preparation

[0125] Modified Leeming & Notman Broth (MLNB)

[0126] 10g Bacteriological Peptone

[0127] 10g Glucose

[0128] 2g Yeast Extract

[0129] 8g Ox bile

[0130] 10ml Glycerol

[0131] 0.5g Glycerol Monostearate

[0132] 5ml Tween 60

[0133] 20ml Olive oil

[0134] Deionized Water to 1000ml

[0135] (Ensure stirring thoroughly including after autoclaving)

[0136] M. restricta (CBS 7877) was maintained on Modified Leeming & Notman Agar (MLNA) agar plate (Solution A). Then, 3 loops of colonies were taken and transferred into a fresh 20ml of growth medium Modified Leeming & Notman broth (MLNB, Solution B). The culture medium was than incubated at 32 oC for 72 hrs with shaking. After incubation, cell density was adjusted to OD=1 for the coming inhibition experiments.

[0137] Working solutions of glycine and magnesium salt were prepared at 20 times of the final concentration as below: Prepare glycine 4% solution with autoclaved deionized water, then get the working solutions with 2 times dilution: 2%, 1%, 0.5%, 0.125%, 0%. Prepare MgCh 6H2O 5%, 4% working solutions with autoclaved deionized water, then obtained 2.5%, 2%, 1.25% and 0% of working solutions through dilutions. 350 L working solutions of glycine and magnesium salt were added to the specific wells of 6 wells plate (corning-3788) before adding culture media. Keep the MLNA medium warm at around 50-60°C. Then 6.3 ml MLNB was added in each well, the cultural medium was mixed well by using a pipette. Till the agar plate went solid, 4 pL of M. restricta inoculum (OD=1) was pipetted on the plate. These were incubated at 32°C for six days and growth status was monitored for each day.

[0138] Final concentrations of the test compounds in each well of the 6-well plate is shown as below:

[0139] Glycine: 1000, 500, 250, 62.5, 0 ppm (13.32, 6.66, 3.33, 0.83, 0 mM).

[0140] MgCI2: 1175, 940, 587.5, 470, 293.75, 0 ppm (12.30, 9.84, 6.15, 4.92, 3.08, 0 mM)

[0141] Step 3: Calculation: 7FIC test

[0142] (1) Minimum Inhibition Concentration (MIC):

[0143] The MIC is defined as the lowest concentration of active compound that inhibits the growth of microbes on the agar plate of cultural medium.

[0144] (2) Fractional Inhibition Concentration (FIC):

[0145] The differing behaviours of inhibitory antimicrobials in isolation and mixtures have been widely explored using the concept of the Fractional Concentration (FC) and Fractional Inhibitory Concentration (FIC). The parameter can be defined as follows: FIC (component a) = MIC (component a tested in the mixture)

[0146] MIC (component a tested as a single active)

[0147] (3) Synergy and Additivity

[0148] The interactions between antimicrobials can be additive, synergistic or antagonistic depending on whether the efficacy of the combination is equivalent to, greater than or less than that obtained for the same total concentration of the individual components when tested alone.

[0149] These relationships can be expressed mathematically by summing the fractional MIC values for all the components present in the mixture to give the “fractional inhibition index”. There is no consistent approach in the academic or patent literature in defining precise limiting EFIC values that differentiate synergy from additivity or antagonism. In this study, we have adopted a liberal approach defining any binary mixture with EFIC < 0.9 as showing evidence of synergistic behaviour.

[0150] EFIC = FIC (component 1) + FIC (component 2)

[0151] EFIC = 1 corresponds to additive microbial inhibition activity EFIC > 1 corresponds to antagonistic microbial inhibition activity

[0152] EFIC < 0.9 corresponds to synergistic microbial inhibition activity

[0153] Results:

[0154] It was observed that there was synergistic effect of glycine with magnesium salt with certain molar ratio against M. restricta (Table 1).

[0155] TABLE 1

[0156] The observations tabulated in Tables 1 clearly indicate that the glycine interacts synergistically with magnesium salt for inhibiting the growth of M. restricts ( FIC<0.9) only when the molar ratio between glycine and magnesium salt is from 1:10 to 4:1 (Examples 1-4) according to the present invention.

[0157] It also implies that is possible to formulate highly efficacious antimicrobial compositions comprising the two active ingredients within the molar ratio range after giving due consideration to the fact that the experiments were conducted under test conditions and the amount of the ingredients may not match or reflect the practical amounts under in-use conditions, i.e., compositions like hair serum, or a shampoo.

[0158] As far as the experiments were concerned, the concentrations of the ingredients were chosen to fall within the allowable limits permitted by the concerned tests and in which it was possible to record the technical effects. Therefore, the concentrations at which the tests were conducted might not appear to fall within the range in which such ingredients are generally used in cosmetic compositions (usually in wt%).

[0159] Example 2

[0160] The impact of inclusion of serine to the combination of glycine and magnesium salt on the antimicrobial efficacy against M. restricta was investigated.

[0161] Glycine and MgCI2 were chosen at the final concentration of 1000 ppm and 470 ppm respectively, different concentrations of serine were selected at the final concentration of:5000 ppm, 0 ppm. The test was conducted using the same FIC assay against M. restricta as disclosed in Example 1.

[0162] Results:

[0163] It was observed that there was negative impact from inclusion of serine to the combination of glycine and magnesium salt on the antimicrobial efficacy against M. restricta (Table 2).

[0164] TABLE 2

[0165] The observations tabulated in Tables 2 clearly indicate that the inclusion of serine (0.5%) in the combination of glycine and magnesium salt has antagonistic effect for inhibiting the growth of M. restricts.

Claims

CLAIMS1. A cosmetic composition comprising i) glycine; and ii) a magnesium salt; wherein the molar ratio of said glycine to said magnesium salt is from 1 :10 to 4:1; wherein the composition comprises less than 0.5% of serine by weight of the composition.

2. A composition as claimed in claim 1 wherein the molar ratio of said glycine to said magnesium salt is from 1:5 to 4:1, preferably from 1 :4 to 3:1.

3. A composition as claimed in claim 1 or 2 wherein said magnesium salt is selected from a group consisting of slightly water-soluble magnesium salt and water-soluble magnesium salt.

4. A composition as claimed in any of claims 1 to 3 wherein said magnesium salt is selected from a group consisting of magnesium carboxylates, magnesium halids, magnesium sulphate, magnesium nitrate, magnesium amino acid complex.

5. A composition as claimed in any of claims 1 to 4 wherein the composition comprises from 0.01 to 10% of glycine by weight of the composition.

6. A composition as claimed in any of claims 1 to 5 wherein the composition comprises from 0.01 to 10% of said magnesium salt by weight of the composition.

7. A composition as claimed in any of claims 1 to 6 wherein the composition comprises a cosmetically acceptable carrier comprising water.

8. A composition as claimed in any of claims 1 to 7 wherein the composition is a leave-on or rinse-off composition, preferably a leave-on composition.

9. A composition as claimed in any of claims 1 to 8 wherein the composition is a hair composition.

10. A composition as claimed in any of claims 1 to 9 wherein the composition comprises a scalp health agent selected from a group consisting of salicylic acid, piroctone compound, hinokitiol, azole compound including climbazole and ketoconazole.

11. A composition as claimed in any of claims 1 to 10 wherein the composition comprises a surfactant.

12. Use of a composition as claimed in any of claims 1 to 11 for providing synergistic antimicrobial benefit on a topical surface of a human or animal body.

13. Use of a composition as claimed in any of claims 1 to 11 for against at least some Malassezia spp on a topical surface of a human or animal body.

14. Use of a composition as claimed in any of claims 1 to 11 for preventing or alleviating the symptoms of dandruff on the scalp or hair.

15. A non-therapeutic method of preventing or alleviating the symptoms of dandruff on the scalp or hair on a topical surface of a human or animal body comprising a step of applying a safe and effective amount of a cosmetic composition as claimed in any of claims 1 to 11.

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