WO2023274774A1

WO2023274774A1 - Hair care composition

Info

Publication number: WO2023274774A1
Application number: PCT/EP2022/066752
Authority: WO
Inventors: Ranjit Kaur Bhogal; Gail Jenkins; Alexandra Claire KENDALL; Anna NICOLAOU; Jennifer Elizabeth Pople; Louise Victoria SMITH
Original assignee: Unilever Ip Holdings B.V.; Unilever Global Ip Limited; Conopco, Inc., D/B/A Unilever
Priority date: 2021-07-01
Filing date: 2022-06-20
Publication date: 2023-01-05
Also published as: AR126283A1

Abstract

A hair care composition comprising at least 0.3 wt% of the total composition of a compound of formula (1), in which R is an unsaturated carbon chain having a chain length from 13 to 21 and an unsaturated chain content of 5 or less double bonds.

Description

HAIR CARE COMPOSITION

Field of the Invention

This invention relates to hair/scalp care compositions, preferably hair and/or scalp treatment compositions and to their use in preventing an anti-inflammatory response on the skin and the associated itch.

Background of the Invention

An itchy scalp is a problem for many and is usually associated with dandruff. It is widely believed that Malassezia yeasts, such as Malassezia furfur, are the main cause of dandruff. However, it is unclear why some people suffer from this condition while others do not.

The scalp/skin is composed of multiple specialized tissues that function as a first line of defence against environmental insults. The skin is dynamic: sensing and responding to even small changes in the environment in order to help maintain homeostasis. Environmental influences such as solar radiation, pollution, or even the application of skin care products, result in a complex cascade of events that ultimately lead to changes in the expression of hundreds or thousands of genes. These changes in gene expression are generally translated to changes in protein production (or accumulation, release, modification etc.) that catalyze chemical reactions ultimately leading to the cellular response.

However, the main, if not only, intervention strategy used on the market currently for the treatment of dandruff is the topical application of antifungals such as zinc pyrithione, (ZnPTO), octopirox, climazole and ketoconazole which are normally delivered from a shampoo. These antifungal agents remove (or at least reduce the level of) the Malassezia from the scalp, and provide effective treatment of the dandruff condition. Although clinically proven to be effective in treating the clinical symptoms of dandruff over a two to four week period.

WO 03/007901 discloses hair and/or scalp treatment compositions comprise an antidandruff agent, an effective amount of a cannabinoid receptor (CBR) activating agent and a cosmetically acceptable diluent or carrier. The compositions said reduce scalp itch, a symptom which is typically associated with dandruff.

However there remains a need to treatskin inflammation and the scalp associated itch effectively and rapidly. Description of the Invention

The first aspect of the present invention relates to a hair/scalp care composition comprising at least 0.3 wt% of the total composition of a compound of formula 1 :

Formula 1

In which R is an unsaturated carbon chain having a chain length from 13 to 21 and an unsaturated chain content of 5 or less double bonds.

A second aspect of the invention is the cosmetic use of a hair/scalp care composition comprising at least 0.3 wt% of the total composition of a compound of formula 1 :

Formula 1 in which R is an unsaturated carbon chain having a chain length from 13 to 21 and an unsaturated chain content of 5 or less double bonds; for mitigating scalp itch.

A third aspect of the invention relates to a hair/scalp care composition comprising at least 0.3 wt% of the total composition of a compound of formula 1 :

Formula 1 in which R is an unsaturated carbon chain having a chain length from 13 to 21 and an unsaturated chain content of 5 or less double bonds, for use in a method for mitigating inflammation of the scalp/skin.

With respect to the present invention ‘cosmetic use’ should be understood to mean non-therapeutic use.

In the context of the present invention 'Hair/scalp Care Composition’ is meant to include a composition for topical application to hair and/or scalp of mammals, especially humans. Non-limiting examples of such compositions include leave-on hair lotions, creams, and wash-off shampoos, conditioners, shower gels, or toilet bar.

For avoidance of doubt, any feature of one aspect of the present invention may be utilised in any other aspect of the invention. Any feature described as ‘preferred’ should be understood to be particularly preferred in combination with a further preferred feature or features. Herein, any feature of a particular embodiment may be utilized in any other embodiment 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. The examples given in the description below are intended to clarify the invention but not to limit the invention. All percentages are weightA/veight 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 or 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, unless specified otherwise. 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 application has found that hair care composition comprising a compound of formula 1 :

Formula 1 in which R is an unsaturated carbon chain having a chain length from 13 to 21 and an unsaturated chain content of 5 or less double bonds can mitigate inflammation of the scalp/skin and thus the associated scalp itch.

The compound of formula 1 described above is preferably present in a composition at a level from 0.05 to 5%, more preferably from 0.1 to 2%, most preferably from 0.2 to 1% (by weight based on the total weight of the composition).

Preferably the compound of formula 1 is selected from N-arachidonoyl ethanolamine (anandamide)(AEA), N-oleoylethanolamine (OEA), N-palmitoleoyl ethanolamine (POEA), dihomo- g-linoleoyl ethanolamine (DGLEA), N-linoleoyl ethanolamine (LEA), N-(2-hydroxyethyl)- Docosapentaenamide (DPEA), Alpha linolenoylethanolamine (ALEA). and mixtures thereof.

Preferably the composition comprises less than 0.5wt% of the total composition of cocamide MEA, more preferably less than 0,1 wt%.

Compositions of the invention may further comprise antidandruff agents such as group consisting of anti-dandruff actives, anti-microbial actives, anti-fungal actives and mixtures thereof., more preferably pyridinethione salts, azoles, selenium sulphide, particulate sulfur, keratolytic agents and mixtures thereof. Particularly preferred are zinc pyrithione, climbazole, piroctone compound such as Octopirox® and mixtures thereof. Formats of the composition

The composition is a scalp/hair care composition.

The cosmetic composition may be an emulsion, lotion, cream, paste or gel. Preferably the composition is a rinse-off composition or a leave-on composition, more preferably a rinse off composition Rinse-off composition is intended to be rinsed off the scalp/hair of the user with water after use. Leave-on composition is intended not to be rinsed off the scalp of the user immediately after use (i.e. within at least the first 2 hours, preferably at least 4 hours after application of the composition). Rinse-off compositions include shampoos and conditioners, as well as treatment compositions which can be left on scalp for from 0.5 minute to up to 2 hours, preferably from 1 minute to 1 hour, more preferably from 2 minutes to 30 minutes, still more preferably from 5 minutes to lOminutes, prior to being rinsed off. Leave on treatments are designed to be left on the hair/scalp for a number of hours, for this invention at least 5 hours before being rinsed off, in many instances the composition is left on the hair/scalp until the hair/scalp is next washed.

The preferred use of the cosmetic composition is in a shampoo. The cosmetic composition may suitably comprise from 50 to 90%, preferably from 60 to 80% water by weight of the total shampoo composition.

Anionic cleansing surfactant

The cosmetic composition may comprise one or more anionic cleansing surfactants. The anionic cleansing surfactants refer to those which have net negative charge and can act to cleanse skin. The total level of anionic cleansing surfactant is suitably from 1 to 45%, by weight of the total composition, preferably from 10 to 25 wt%.

Preferably, the anionic cleansing surfactant is alkyl sulphate and/or ethoxylated alkyl sulphate anionic surfactant. The preferred level of such surfactant is from 0.5 to 20% by weight of the total composition, more preferably from 5 to 15wt%.

Preferred alkyl sulphates are Cs-is alkyl sulphate, more preferably C12-18 alkyl sulphate, 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).

Preferred alkyl ether sulphates are those of formula (II):

R-0-(CH₂CHr0)n-S0₃-M (II) wherein R is a straight or branched alkyl chain having 8 to 18 (preferably 12 to 18) carbon atoms; n is the average degree of ethoxylation and ranges from 0.5 to 3 (preferably from 1 to 3); and M is a solubilizing cation such as sodium, potassium, ammonium or substituted ammonium. An example is sodium lauryl ether sulphate (SLES). The most preferred example is SLES having an average degree of ethoxylate of from 0.5 to 3, preferably from 1 to 3.

The cosmetic composition may comprise one or more further anionic surfactants which are cosmetically acceptable and suitable for topical application to skin. Examples of further anionic surfactants include alkyl sulphonates, 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 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 cleansing surfactants for use in the compositions include sodium oleyl succinate, ammonium lauryl sulphosuccinate, sodium lauryl ether sulphosuccinate, sodium dodecylbenzene sulphonate, triethanolamine dodecylbenzene sulphonate, lauryl ether carboxylic acid and sodium N-lauryl sarcosinate.lauric monoglyceride sodium sulphate, sodium lauryl sulphate, sodium laureth sulphate, sodium cocyl sulphate, sodium cocoyl isethionate and mixtures thereof.

The cosmetic composition may also include co-surfactants, to help impart aesthetic, physical or cleansing properties to the composition. The co-surfactant is preferably comprised in the cleansing phase of the composition. An example of a co-surfactant is a nonionic surfactant, which can be included in an amount ranging from 0.5 to 10%, preferably from 2 to 8%, more preferably from 1 to 5% by weight of the total composition.

For example, representative nonionic surfactants that can be included in the cosmetic compositions, preferably shampoo compositions of the invention include condensation products of aliphatic (Cs - Cie) primary or secondary linear or branched chain alcohols or phenols with alkylene oxides, usually ethylene oxide and generally having from 6 to 30 ethylene oxide groups. Other representative nonionic surfactants include mono- or di-alkyl alkanolamides. Examples include coco mono- or di-ethanolamide and coco mono- isopropanolamide. Further nonionic surfactants which can be included are the alkyl polyglycosides (APGs). Typically, the APG is one which comprises an alkyl group connected (optionally via a bridging group) to a block of one or more glycosyl groups. Preferred APGs are defined by the following formula (III):

R^’O - (G)k (III) wherein R^’ is a branched or straight chain alkyl group which may be saturated or unsaturated and G is a saccharide group. R^’ may represent a mean alkyl chain length of from about C5 to about C20. Preferably R^’ represents a mean alkyl chain length of from about Cs to about C12. Most preferably the value of R^’ lies between about 9.5 and about 10.5. G may be selected from C5 or C₆ monosaccharide residues and is preferably a glucoside. G may be selected from the group comprising glucose, xylose, lactose, fructose, mannose and derivatives thereof. Preferably G is glucose. The degree of polymerisation, k, may have a value of from about 1 to about 10 or more; preferably, the value of k lies from about 1.1 to about 2; most preferably the value of m lies from about 1.3 to about 1.5.

Suitable alkyl polyglycosides for use in the invention are commercially available and include for example those materials identified as: Oramix NS10 ex Seppic; Plantaren 1200 and Plantaren 2000 ex Henkel.

Other sugar-derived nonionic surfactants which can be included in compositions (preferably shampoos) of the invention include the C10-C18 N-alkyl (Oi-Ob) polyhydroxy fatty acid amides, such as the C12-C18 N-methyl glucamides, as described for example in WO 92/06154 and US 5,194, 639, and the N-alkoxy polyhydroxy fatty acid amides, such as C10-C18 N-(3- methoxypropyl) glucamide.

A preferred example of a co-surfactant is an amphoteric or zwitterionic surfactant, which can be included in an amount ranging from 0.5 to about 10 wt.%, preferably from 2 to 8, more preferably from 1 to 5 % by weight of the total composition.

Examples of amphoteric or zwitterionic surfactants include alkyl amine oxides, alkyl betaines, alkyl amidopropyl betaines, alkyl sulphobetaines (sultaines), alkyl glycinates, alkyl carboxyglycinates, alkyl amphoacetates, alkyl amphopropionates, alkylamphoglycinates, alkyl amidopropyl hydroxysultaines, acyl taurates and acyl glutamates, wherein the alkyl and acyl groups have from 8 to 22 carbon atoms. Typical amphoteric and zwitterionic surfactants for use in shampoos of the invention include lauryl amine oxide, cocodimethyl sulphopropyl betaine, lauryl betaine, cocamidopropyl betaine and sodium cocoamphoacetate.

A particularly preferred amphoteric or zwitterionic surfactant is an amidobetaine amphoteric surfactant of general formula (IV):

wherein m is 2 or 3; R¹C(0) is selected from linear or branched, saturated or unsaturated acyl groups having from 8 to 22 carbon atoms and mixtures thereof; and R² and R³are each independently selected from alkyl, hydroxyalkyl or carboxyalkyl groups having from 1 to 6 carbon atoms and mixtures thereof. An example is cocamidopropyl betaine. The preferred level of such surfactant is from 0.5-10% by weight of the total composition, more preferably from 2-8 wt%, most preferably from 1-5 wt%.

A further optional but preferred surfactant is an alkyl glycinate and/or alkyl carboxyglycinate. If present, it is present at a level of from 1 to 8 wt.%, preferably 2 to 6 wt.%

Preferably the alkyl glycinate and/or alkyl carboxyglycinate has an alkyl group of from Cs-22 carbon atoms, in the form of a salt with a solubilising cation such as sodium, potassium, ammonium or substituted ammonium. Preferred glycinates are sodium coco glycinate and sodium cocoyl glycinate.

Mixtures of any of the foregoing amphoteric or zwitterionic surfactants may also be suitable. Preferred mixtures are those of cocamidopropyl betaine with further amphoteric or zwitterionic surfactants as described above. A preferred further amphoteric or zwitterionic surfactant is sodium cocoamphoacetate.

In preferred embodiments, the cosmetic composition comprises an alkyl sulphate and/or ethoxylated alkyl sulphate anionic surfactant; and a betaine surfactant, preferably an alkyl amidopropyl betaine. The total amount of surfactants (inclusive of any co-surfactants) in a cosmetic composition, is generally from 1 to 50 wt.%, preferably from 2 to 40 wt.%, more preferably from 10 to 25 wt.% by weight of the total composition.

Cationic deposition polymer

The cosmetic composition may comprise at least one cationic deposition polymer. The level of the cationic polymer is suitably from 0.01 to 5%, by weight of the total composition, preferably from 0.05 to 2 wt%, more preferably from 0.1 to 1 wt%, most preferably from 0.1 to 0.5 wt%. The preferred choice of a cationic deposition polymer is a guar hydroxypropyltrimmonium chloride polymer.

The cationic deposition polymer is often used in cosmetic composition for enhancing conditioning and other sensory performance. In the present invention, it is believed that the inclusion of cationic polymer can help to enhance the delivery efficiency of piroctone olamine to the desired skin area, hence the improvement of skin natural defence.

Suitable cationic deposition polymers include cationic polygalactomannans, which are polysaccharides composed principally of galactose and mannose units and are usually found in the endosperm of leguminous seeds, such as guar, locust bean, honey locust, flame tree, and the like. Guar flour is composed mostly of a galactomannan which is essentially a straight chain mannan with single membered galactose branches. The mannose units are linked in a 1-4^-glycosidic linkage and the galactose branching takes place by means of a 1-6 linkage on alternate mannose units. The ratio of galactose to mannose in the guar polymer is therefore one to two. Preferred cationic polygalactomannans are guar hydroxypropyltrimonium choride polymers.

Guar hydroxypropyltrimethylammonium chlorides for use in the invention are generally comprised of a nonionic guar gum backbone that is functionalized with ether-linked 2- hydroxypropyltrimethylammonium chloride groups and are typically prepared by the reaction of guar gum with N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride.

Generally, the guar hydroxypropyltrimethylammonium chlorides have an average molecular weight (weight average molecular mass (Mw) determined by size exclusion chromatography) in the range 500,000 to 3 million g/mol, more preferably 800,000 to 2.5 million g/mol.

Generally, the guar hydroxypropyltrimethylammonium chlorides have a charge density ranging from 0.5 to 1.8 meq/g. The cationic charge density of the polymer is suitably determined via the Kjeldahl method as described in the US Pharmacopoeia under chemical tests for nitrogen determination. Preferred guar hydroxypropyltrimonium chlorides have a cationic charge density from 1.1 to 1.8 meq/g. Also suitable are mixtures of guars in which one has a cationic charge density from 0.5 to 1.1 meq/g, and one has a cationic charge density from 1.1 to 1.8 meq per gram.

Guar hydroxypropyltrimethylammonium chlorides for use in the invention are commercially available from Rhodia as JAGUAR ® C13S, JAGUAR ® C14 and JAGUAR ® C17. Also preferred is boron-free crosslinked cationic guar hydroxypropyltrimethylammonium chloride, such as the guar polymer from Lambeti as Cesmetic ® BF-7.

Other suitable cationic polymers for use in the present invention include polysaccharide polymers, such as cationic cellulose derivatives and cationic starch derivatives. Preferred cationic cellulose polymers are salts of hydroxyethyl cellulose reacted with trimethyl ammonium substituted epoxide, referred to in the industry (CTFA) as polyquaternium 10 and available from Dow Chemical as UCARE™ Polymer JR-30M. Other suitable types of cationic cellulose include the polymeric quaternary ammonium salts of hydroxyethyl cellulose reacted with lauryl dimethyl ammonium-substituted epoxide referred to in the industry (CTFA) a Polyquaternium 24.

Other optional components

The cosmetic composition may optionally comprise one or more components, provided that the optional components are physically and chemically compatible with the essential components described hereinbefore, and do not otherwise unduly impair sensory, formulation rheology and conditioning performance. Individual concentrations of such optional components may range from 0.001 % to 10% by weight of the total composition, preferably from 0.01 % to 5%wt%. Such components may include suspending agents, conditioning agents, fragrance, dyes, pigments, pH adjusting agents, pearlescers or opacifiers, viscosity modifiers, preservatives, and natural hair nutrients such as botanicals, fruit extracts, sugar derivatives and amino acids.

One of the preferred optional components is 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 acid-containing 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. Mixtures of any of the above suspending agents may be used. Preferred is a mixture of cross-linked polymer of acrylic acid and crystalline long chain acyl derivative.

A most preferred example is a crosslinked polyacrylate polymer.

Suspending agent, if included, will generally be present in the composition at a level of from 0.01 to 5 wt.%, preferably from 0.1 to 2.5 wt.%, more preferably from 0.25 to 1 wt.%.

Another preferred optional component is a conditioning agent, providing conditioning benefit. Typically, the most popular conditioning agents used in cosmetic compositions are water-insoluble oily materials such as mineral oils, naturally occurring oils such as triglycerides and silicone oils. Conditioning benefit is achieved by the oily material being deposited onto the skin resulting in the formation of a film, which makes the skin more lubricant and less dry. Preferably, the conditioning agent is non-volatile, meaning that it has a vapour pressure of less than 1000 Pa at 25°C.

Preferably, the 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.

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

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.

The viscosity of the emulsified silicone itself (not the emulsion or the final hair care composition) is typically at least 10,000 cSt (centi-Stokes=mm² S¹) at25°C, preferably at least 60,000 cSt, most preferably at least 500,000 cSt, ideally at least 1 ,000,000 cSt. Preferably the viscosity does not exceed 10⁹ cSt for ease of formulation. Suitable methods for measuring the kinematic viscosity of silicone oils are known to those skilled in the art, e.g. capillary viscometers. For high viscosity silicones, a constant stress rheometer can be used to measure viscosity.

Suitable emulsified silicones for use in the compositions are available as pre-formed silicone emulsions from suppliers of silicones such as Dow Coming and GE silicones. The use of such preformed 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.

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.”

Preferably, silicone emulsion droplets are blended with certain types of surface active block polymers of a high molecular weight to form silicone emulsions, as described for example in WO03/094874. One preferred form of the surface active block polymer having polyoxypropylene and polyoxyethylene groups as the hydrophobic and hydrophilic part respectively has formula V and has the CTFA designation poloxamer, known commercially under the trade name “Pluronic” from BASF.

V ) H0(CH2CH20)x(CH(CH3)CH20)_y(CH2CH₂0)x H Suitably, the mean value of x in formula I is 4 or more, preferably 8 or more, more preferably 25 or more, yet more preferably 50 or more and most preferably 80 or more. The mean value of x is typically no greater than 200. Suitably, the mean value of y is 25 or more, preferably 35 or more, more preferably 45 or more and most preferably 60 or more. The mean value of y is typically no greater than 100.

Another preferred form of the surface active block polymer is according to formula VI and has the CTFA designation Poloxamine. Those are commercially available under the trade name “Tetronic” from BASF.

VI) (H0(CH2CH20)a(CH(CH3)CH20)b)rN-CHrCHrN-((0CH2CH(CH3))b(0CH₂CH2)a0H)2

Suitably, the mean value of a is 2 or more, preferably 4 or more, more preferably 8 or more, even more preferably 25 or more and most preferably 40 or more. The mean value of a is typically no greater than 200. The mean value of b is suitably 6 or more, preferably 9 or more, more preferably 11 or more and most preferably 15 or more. The mean value of b is typically no greater than 50.

Preferably, the surface active block polymer is poloxamer and/or poloxamine, more preferably, the surface active block polymer is poloxamer.

Preferably, the surface active block polymer is blended with dimethicone. The weight ratio of dimethicone to surface active block polymer in the blend is preferably in the range from 2: 1 to 200: 1 , more preferably from 5: 1 to 50: 1 , even more preferably from 10: 1 to 40: 1 , most preferably from 15: 1 to 30:1.

The water-insoluble conditioning agent is generally present in the composition 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 the total weight of the composition and including all ranges subsumed therein.

The composition may preferably comprise a pearlescer. The preferred pearlescer is ethylene glycol ester as disclosed in US4885107, incorporated herein by reference. Preferably, the ethylene glycol ester is a mono- or, di-ester of glycol, more preferably a di-ester of glycol.

Preferably ethylene glycol mono- or di-ester is an ethylene glycol mono- or di-ester of a C12-22 fatty acid, more preferably an ethylene glycol mono- or di-ester of a saturated C12-22 fatty acid. Most preferred are the diesters comprising a mixture of palmitate and stearate. The amount of stearate should be in the range of about 10% to about 42% or in the range of about 55% to about 80% with palmitate accounting for the remainder. The amount of stearate is preferably from about 60% to about 75%, more preferably from about 80-95%, most preferably 100%. The most suitable example of a pearlescer is an ethylene glycol distearate. Pearlescer may also perform the function as a suspending agent.

The level of the ethylene glycol ester can be suitably from about 0.5% to about 6%, preferably from about 1 % to about 4%, by weight of the total composition.

The viscosity of the composition suitably ranges from 3,000 to 10,000 mPa.s, preferably from 4,000 to 8,000 mPa.s, more preferably from 5,000 to 7,000 mPa.s when measured using a Brookfield V2 viscometer (spindle RTV5, 1 minute, 20rpm) at 30°C.

The pH of the composition of the invention preferably ranges from 3 to 9, more preferably from 5 to 7, still more preferably from 5.5 to 6.5.

The present invention is illustrated by means of the following non-limiting examples. Examples of the invention are illustrated by a number, comparative Examples are illustrated by a letter.

Examples

Two skin punch were taken from active dandruff regions from 8 dandruff volunteers (samples for lipid analysis were snap-frozen and stored at -80°C).

Lipid extractions and analysis by UPLC-MS/MS and UHPSFC-MS

/V-acyl ethanolamines (NAE) and ceramides were extracted and analysed (Kendall AC, Pilkington SM, Sassano G etal. N-Acyl ethanolamide and eicosanoid involvement in irritant dermatitis.

BrJ Dermatol 2016; 175: 163-71 & Kendall AC, Kiezel-Tsugunova M, Brownbridge LC etal. Lipid functions in skin: Differential effects of n-3 polyunsaturated fatty acids on cutaneous ceramides, in a human skin organ culture model. Biochimica etBiophysica Acta (BBA) - Biomembranes 2017;

1859: 1679-89.) Briefly, dermis and epidermis were separated and homogenised in chloroform: methanol (2:1) with deuterated internal standards (20ng AEA-d3, Cayman Chemical, Ann Arbor, Ml; 50pmol CER[N(25)S(18)], Avanti Polar Lipids, Alabaster, AL). Lipid extracts were analysed by ultraperformance liquid chromatography coupled to electrospray ionisation tandem mass spectrometry (UPLC/ESI-MS/MS).

Lipid levels were normalised against tissue protein content, quantified using Bio-Rad protein assay II. Subjects were recruited and their scalp health was graded according to the presence or absence of scalp skin flakes. If flakes were present, they were classified as suffering from dandruff, if there were no scalp skin flakes present they were classified as healthy. The level of active compound was assessed for subjects suffering from dandruff compared with subjects with a healthy scalp. The results obtained were as follows:

The results show increased level of active compound for people suffering from dandruff indicating this is the body’s natural way of combatting the deleterious effects of dandruff. Thus, compositions comprising these compounds mimic the body’s natural response to mitigate the adverse effects of dandruff.

The following is an example of a shampoo composition according to the invention:

Ingredient Example 8 weight percent

SLES 2EO 14

Cocoamidopropylbetaine 2

Guar hydroxypropyltrimonium chloride 0.1

Dimethiconol 1

Crosslinked polyacrylic acid 0.4

Alpha Linolenoyl ethanolamine 0.6

Mica + titanium dioxide 0.2

Sodium benzoate 0.5

Water to 100

Claims

1. A hair/scalp care composition comprising at least 0.3 wt% of the total composition of compound of formula 1:

Formula 1 in which R is an unsaturated carbon chain having a chain length from 13 to 21 and an unsaturated chain content of 5 or less double bonds.

2. A hair/scalp care composition according to claim 1 in which the level of compound of formula 1 is from 05 wt% to 5 wt% of the total composition.

3. A hair /scalpcare composition according to claim 1 or claim 2 in which the compound of formula 1 is selected from ; N-arachidonoyl ethanolamine (anandamide)(AEA), N- oleoylethanolamine (OEA), N-palmitoleoyl ethanolamine (POEA), dihomo-g-linoleoyl ethanolamine (DGLEA), N-linoleoyl ethanolamine (LEA), N-(2-hydroxyethyl)- Docosapentaenamide (DPEA), Alpha linolenoylethanolamine (ALEA) and mixtures thereof.

4. A hair/scalp care composition according to any preceding claim that comprises less than 0.5wt% of the total composition of cocamide MEA, preferably less than 0,1 wt%.

5. A hair/scalp care composition according to any preceding claim that is a shampoo composition.

6. A hair/scalp care composition according to any preceding claim that further comprise a surfactant.

7. A hair care composition according to claim 6 in which the surfactant comprises an anionic surfactant.

8. A hair care composition according to any preceding claim that comprises a polymeric thickener.

9. A hair care composition according to any preceding claim that further comprises a silicone.

10. A persona care composition according to any preceding claim that further comprises a cationic deposition polymer.

11. A method for washing the hair/scalp comprising the following steps: i) application of a composition according any preceding claim to the hair and scalp ii) rinsing the composition with water.

12. Cosmetic use of a hair/scalp care composition comprising at least 0.3 wt% of the total composition a compound of formula 1 :

Formula 1 in which R is an unsaturated carbon chain having a chain length from 13 to 21 and an unsaturated chain content of 5 or less double bonds; for mitigating scalp itch

13. A hair/scalp care composition comprising at least 0.3 wt% of the total composition ofa compound of formula 1: