GB2311995A - Antimicrobial hair treatment composition - Google Patents

Abstract

An antimicrobial hair treatment composition is a shampoo composition comprising an antimicrobial compound selected from certain 1-hydroxy-6-substituted pyridine-2-one and 2-thione compounds, and a shampoo surfactant, in which the pH of the hair treatment composition is adjusted to at least 7. In this way the solubility of the antimicrobil active, and hence the optical clarity of the final formulation, can be maintained, allowing transparent formulations to be made.

Description

ANTIMfCROBIAL HAIR TREATb(ENT COMPOSZTZON FIELD OF THE INVENTON This invention relates to a hair treatment composition, and particularly to a hair treatment composition containing an antimicrobial agent and which is transparent.

Backaround and Prior Art Hair treatment compositions are often desired to be transparent, i.e. optically clear or substantially clear.

This is not only of benefit as regards visual product appeal to the consumer, but also conveys a perception of It lightness", which is particularly important for people whose hair is naturally greasy, for whom overconditioning associated with conventional opaque formulations can lead to dullness and a heavy, coated feel.

Insoluble particulate metal pyrithiones are the predominant antimicrobial agents encountered in antimicrobial composition9, such as antidandruff hair shampoos and conditioners. The zinc salt (hereinafter referred to as ZnPTO) is widely used in this context. A problem is that the insolubility of ZnPTO renders it unsuitable for transparent formulations. Generally, dispersed particles of the ZnPTO are suspended in the composition. Furthermore, thickeners or bulking agents, such as clays and pearlescers, frequently have to be added to give structural viscosity to the system and prevent ZnPTO separation and settlement during storage.

Such additives cloud the product further and lead to aesthetic unacceptability. A particular problem with ZnPTO containing formulations is chalkiness.

It is also known that certain l-hydroxy-2-pyridone derivatives are effective as antimicrobial agents with specific applicability to dandruff control. l-hydroxy-4 methyl-6-(2,4,4-trimethylpentyl) -2-pyridone has been described in US 4,185,106 and US 4.311.775 as exhibiting good antimicrobial efficacy and solubility in shampoo formulations. The compound is, however, expensive to prepare.

W095/11233 describes a specific class of l-hydroxy-6substituted gyridine-2-ones and 2-thiones, a process for their preparation and their use as antimicrobials in industrial and cosmetic applications generally, ranging from soaps and shampoos to sealants and other polymer compositions, most especially paints. The compounds are stated to be soluble in water and organic solvents.

We have now found that under acidic pH conditions. as are commonly found in hair treatment compositions, the compounds of W095/1l233 although highly effective as antimicrobial agents, are rendered insoluble in the composition and thus unsuitable for transparent formulations. By adjusting the pH of the composition to at least 7, however, the solubility of the active, and hence the optical clarity of the final formulation, can be maintained.

SUMMARY OF THE INVENTION The present invention provides an antimicrobial hair treatment composition comprising the following components: (a) an antimicrobial compound of the formula:

wherein X is an oxygen or sulphur moiety and R is a substituted or unsubstituted hydrocarbon radical having between 1 and 20 carbon atoms. with the proviso that R is other than chlorobenzyl, and R' is hydrogen or a cation selected from the group consisting of alkali metals, alkaline earth metals, ammonium ion and organic ammonium ions, or a compound of the formula

wherein Y is an oxygen, sulphur, or NR" moiety wherein N is nitrogen and R and R are independently each a substituted or unsubstituted hydrocarbon radical having between 1 and 20 carbon atoms, or a compound of the formula:

wherein RIII and RIV are independently either hydrogen or a substituted or unsubstituted hydrocarbon radical having between 1 and 20 carbon atoms, with the proviso that either R or R11 is a hydrocarbon radical; and (b) at least one surfactant, in which the pH of the hair treatment composition is at least 7, so that the antimicrobial compound is soluble in the hair treatment composition.

Detailed Descrintion and Preferred Embodiments Preferred hydrocarbon radicals for the R group in the above formulae ( (11) and (III) are aliphatic hydrocarbons having between 3 and 15 carbons, more preferably a straight chain hydrocarbon having between 5 and 10 carbons. The term "substituted hydrocarbon" is intended to include substituents such as halogen, chloro, iodo, fluoro or bromo, alkoxy such as methoxy, ethoxy, propoxy or butoxy, nitro, thio, amino combinations thereof, and che like. Illustrative hydrocarbon groups include n-octyl, 2.4,4-erimethylpenty1, 3,5,5 trimethyihexyl, combinations thereof, and the like.

Examples of R include sodium, lithium, potassium, calcium, magnesium, ammonium, and mono-, di-, or tri-ethanolamine.

A preferred antimicrobial compound in accordance with the invention is the monoethanolamine salt of the compound of formula (I) where R = octyl and X = oxygen.

The amount of antimicrobial compound incorporated into the compositions of the invention may depend on the type of composition and the exact nature of the material used. A preferred amount of antimicrobial compound is from about 0.001 to about 5% by weight of the total composition, more preferably from about 0.1 to about 3% by weight.

The composition according to the invention comprises at least one surfactant, preferably chosen from anionic, cationic, nonionic1 amphoteric and zwitterionic surfactants, and mixtures thereof.

A particularly preferred hair treatment composition in accordance with the invention is a shampoo composition in which at least one surfactant provides a deterging benefit.

The deterging surfactant is preferably selected from anionic, nonionic, amphoteric and zwitterionic surfactants, and mixtures thereof.

Suitable anionic surfactants include the alkyl sulphates, alkyl ether sulphates, alkaryl sulphonates, alkanoyl isethionates, alkyl succinates, alkyl sulphosuccinates, Nalkoyl sarcosinates. alkyl phosphates, alkyl ether phosphates, alkyl ether carboxylates, and alpha-olefin sulphonates, especially their sodium, magnesium, ammonium and mono- di- and triethanolamine salts. The alkyl and acyl groups generally contain.from 8 to 18 carbon atoms and may be unsaturated. The alkyl ether sulphates, alkyl ether phosphates and alkyl ether carboxylates may contain from one to 10 ethylene oxide or propylene oxide units per molecule, and preferably contain 2 to 3 etheylene oxide units per molecule.

Examples of suitable anionic surfactants include sodium oleyl succinate, ammonium lauryl suiphosuccinate, ammonium lauryl sulphate, sodium dodecylbenzene sulphonate, triethanolamine dodecylbenzene sulphonate, sodium cocoyl isethionate, sodium lauroyl isethionate and sodium N-lauryl sarcosinate. The most preferred anionic surfactants are sodium lauryl sulphate, triethanolamine lauryl sulphate, triethanolamine monolauryl phosphate, sodium lauryl ether sulphate lEO, 2Eo and 3EO, ammonium lauryl sulphate and ammonium lauryl ether sulphate lEO, 2EO and 3Eo.

Nonionic surfactants suitable for use in composition of the invention may include condensation products of aliphatic (C- Clue) 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 group. Other suitable nonionics include mono- or di-alkyl alkanolamides.

Examples include coco mono- or di-ethanolamide and coco mono isopropanolamide.

Amphoteric and zwitterionic surfactants suitable for use in compositions of the invention may include alkyl amine oxides, alkyl betaines, alkyl amidopropyl betaines, alkyl sulphobetaines (sultaines), alkyl glycinates, alkyl carboxyglycinates, alkyl amphopropionates, alkylarriphoglycinates alkyl amidopropyl hydroxysultaines, acyl taurates and acyl glutamates, wherein the alkyl and acyl groups have from 8 to 19 carbon atoms. Examples include lauryl amine oxide, cocodimethyl suiphopropyl betaine and preferably lauryl betaine, cocamidopropyl betaine and sodium cocamphopropionate.

The surfactants are present in shampoo compositions of the invention in an amount of from 0.1 to 50% by weight, preferably from 0.5 to 30% by weight.

Hair treatment compositions in accordance with the invention may also take the form of hair conditioning compositions, which preferably comprise one or more cat ionic surfactants.

The use of cat ionic surfactants is especially preferred, because these ingredients are capable of providing conditioning benefits to hair.

Examples of cat ionic surfactants include: quaternary ammonium hydroxides, e.g., tetrsmethylammonium hydroxide, alkyltrimethylammonium hydroxides wherein the alkyl group has from about 8 to 22 carbon atoms, for example octyltrimethylaznmonium hydroxide, dodecyltrimethy- ammonium hydroxide, hexadecyltrimethylarnnonium hydroxide, cetyltrimethylammonium hydroxide, octyldimethylbenzylammonium hydroxide, decyldimethyl- benzylammonium hydroxide, stearyldi-methylbenzylammonium hydroxide, didodecyldimethylammonium hydroxide, dioctadecyldimethylammoniurn hydroxide, tallow trimethylammonium hydroxide, cocotrimethylammonium hydroxide, and the corresponding salts thereof, e.g., chlorides Cetylpyridinium hydroxide or salts thereof e.g., chloride Quaternium -5 Quaternium -31 Quaterniurn -18 and mixtures thereof.

In hair conditioning compositions according to the invention, the level of cationic surfactant is preferably from 0.01 to 10t, more preferably 0.05 to 5%, most preferably 0.1 to 2% by weight of the composition.

Hair treatment compositions of the invention may also contain one or more conditioning agents, as are well known in the art. The conditioning agents may include silicones, protein hydrolyzates, quaternised protein hydrolysates, and other materials which are known in the art as having desirable hair conditioning properties.

Silicones are the most preferred conditioning agents.

Suitable silicones include volatile and non-volatile silicones, such as for example polyalkylsiloxanes, polyalkylaryl siloxanes, siloxane gums and resins, cyclomethicones, aminofunctional silicones, quaternary silicones and mixtures thereof. Silicone oil is a particularly preferred conditioning agent for hair.

The silicone oil may suitably be a polydimethylsiloxane with an average particle size of less than 20 microns and preferably less than 2 microns. Small particle size enables a more uniform distribution of silicone conditioning agent for the same concentration of silicone in the composition.

Particularly preferred are silicone microemulsions, in view of their transparency.

Advantageously, a silicone with a viscosity in the range 1-20 million cst is used. The silicone is preferably emulsionpolymerised, since this enables silicones of very high viscosity to be more easily processed. The silicone can be cross-linked.

Suitable protein hydrolysates include lauryl dimonium hydroxy propylamino hydrolysed animal protein, available commercially under the trade name LAMEQUAT L, and hydrolysed keratin containing sulphur-bearing amino acids, available commercially under the trade name CROQUAT WKP.

The hair treatment composition may also contain a polymeric water-soluble deposition aid for the antimicrobial compound.

By "deposition aid" is meant an agent which enhances deposition of the antimicrobial compound on the intended site, i.e., the hair and/or the scalp.

The deposition aid will generally be present at levels of from 0.01 to 5%, preferably from about 0.5 to 1%, more preferably from about 0.08% to about 0.5% by weight. The deposition aid may be a homopolymer or be formed from two or more types of monomers. The molecular weight of the polymer will generally be between 5 000 and 20 000 000, typically at least 10 000 and preferably in the range 100 000 to about 10 000 000. The polymers will have cationic nitrogen containing groups such as quaternary ammonium or protonated amino groups, or a mixture thereof.

The cat ionic charge density of the deposition aid, which is defined as the reciprocal of the molecular weight of a monomeric unit of the polymer containing 1 charge, has been found to need to be at least 0.1 meq/g, preferably above 0.8 or higher. The cat ionic charge density should not exceed 4 meq/g, it is preferably less than 3 and more preferably less than 2 meq/g. The charge density can be measured using conductimetric analysis and should be within the above limits at the desired pH of use, which will be at least 7 and preferably between 7.5 and 9.5.

The cat ionic nitrogen-containing group will generally be present as a substituent on a fraction of the total monomer units of the deposition aid. Thus when the polymer is not a homopolymer it can contain spacer non-cationic monomer Units.

Such polymers are described in the CTFA Cosmetic Ingredient Directory, 3rd edition. The ratio of the cationic to noncat ionic monomer units is selected to give a polymer having a cat ionic charge density in the required range.

Suitable cationic deposition aids include, for example, copolymers of vinyl monomers having cat ionic amine or quaternary ammonium functionalities with water soluble spacer monomers such as (meth)acrylamide, alkyl and dialkyl (meth)acrylamides, alkyl (meth)acrylate, vinyl caprolactone and vinyl pyrrolidine. The alkyl and dialkyl substituted monomers preferably have C1-C7 alkyl groups, more preferably C1-3 alkyl groups. Other suitable spacers include vinyl esters, vinyl alcohol, maleic anhydride. propylene glycol and ethylene glycol.

The cat ionic amines can be primary, secondary or tertiary gamines, depending upon the particular species and the pX of the composition. In general secondary and tertiary amines, especially tertiary, are preferred.

Amine substituted vinyl monomers and amines can be polymerized in the amine form and then converted to ammonium by quaternization.

Suitable cat ionic amino and quaternary ammonium monomers include, for example, vinyl compounds substituted with dialkyl aminoalkyl acrylate, dialkylamino alkylmethacrylate, monoalkylaminoalkyl acrylate, monoalkylaminoalkyl methacrylate, trialkyl methacryloxyalkyl ammonium salt, trialkyl acryloxyalkyl ammonium salt, diallyl quaternary ammonium salts, and vinyl quaternary ammonium monomers having cyclic cat ionic nitrogen-containing rings such as pyridinium, imidazolium, and quaternized pyrrolidine, e.g., alkyl vinyl imidazolium alkyl vinyl pyridinium, and alkyl vinyl pyrrolidine salts. The alkyl portions of these ,monomers are preferably lower alkyls such as the C,-C; alkyls, more preferably C, and C alkyls.

Suitable amine-substituted vinyl monomers for use herein include dialkylaminoalkyl acrylate, dialkylaminoalkyl methacrylate, dialkylaminoalkyl acrylamide, and dialkylaminoalkyl methacrylamide, wherein the alkyl groups are preferably C1-C, hydrocarbyls, more preferably Cl-C3, alkyls.

The deposition aid can comprise mixtures of monomer units derived from amine- and/or quaternary ammonium-substituted monomer and/or compatible spacer monomers.

Suitable deposition aids include, for example: cationic copolymers of l-vlnyl-2-Dyrrolidine and l-vinyl-3-methylimidazolium salt (e.g., Chloride salt) (referred to in the industry by the Cosmetic, Toiletry, and Fragrance Association, "CTFA". as Polyquaternium-16); copolymers of 1vinyl-2-pyrrolidine and dimethylaminoethyl methacrylate (referred to in the industry by CTFA as Polyquaternium-ll); cat ionic diallyl quaternary ammonium-containing polymers including, for example, dimethyldiallylarnmonium chloride homopolymer (referred to in the industry (CTFA) as Polyquaternium 6); mineral acid salts of amino-alkyl esters of homo-and co-polymers of unsaturated carboxylic acids having from 3 to 5 carbon atoms, as described in U.S. Patent 4,009,256; and cationic polyacrylamides as described in w095/22311.

Other cat ionic deposition aids that can be used include cationic guar gum derivatives, such as guar hydroxypropyltrimonium chloride (Commercially available from Celanese Corp. in their Jaguar trademark series).

Examples are JAGUAR Cl3S, which has a low degree of substitution of the cat ionic groups and high viscosity.

JAGUAR C15, having a moderate degree of substitution and a low viscosity, JAGUAR C17 (high degree of substitution, high viscosity) JAGUAR C16, which is a hydroxypropylated cationic guar derivative containing a low level of substituent groups as well as cationic quaternary ammonium groups, and JAGUAR 162 which is a high transparency, medium viscosity guar having a low degree of substitution.

Preferably the deposition aid is selected from the group comprising cationic polyacrylamides, and cationic guar derivatives. Particularly preferred deposition aids are Jaguar Cl3S with a cationic charge density of 0.8meq/g.

Other particularly suitable materials include Jaguar C15, Jaguar C17 and Jaguar C16 and Jaguar C162.

The hair treatment compositions of the invention are preferably aqueous based. The compositions suitably comprise water in amount of from about 20 to about 99% by weight of the total composition.

The compositions of the invention are preferably rinse-off compositions, i.e.. suitable for applying to the hair andXor scalp, left thereon for an appropriate period of time and then rinsed off with water. Thus. shampoos are a particularly preferred product form for compositions of the invention.

Depending on the type of composition employed, one or more additional ingredients conventionally incorporated into hair treatment formulations may be included in the compositions of the invention. Such additional ingredients include polymer lattices, additional antimicrobial agents such as ZnPTO and Octopirox, foam boosters, perfumes, colouring agents, preservatives, viscosity modifiers, proteins, polymers, buffering or pH adjusting agents, moisturising agents, herb or other plant extracts and other natural ingredients.

In a further aspect of the present invention there is provided a method of preparing an antimicrobial hair treatment composition which method comprises mixing together the components (a), (b) and (c) as are defined above, and adjusting the gH of the resultant composition to at least 7, so that the antimicrobial compound of component (a) is soluble in the final hair treatment composition.

Formulations of the present invention have the advantage that thickeners or suspending agents, which can adversely affect optical clarity, are not required for the antimicrobial compound. In this way optical clarity of the final formulation may be preserved, without comprising product stability.

The invention is further illustrated by way of the following non-limitative examples.

EXAMPLE An antimicrobial shampoo composition was made up from the following ingredients: 14% Sodium lauryl ether sulphate 2EO 2% Cocamidopropyl betaine 0.5% Sodium benzoate 0.3% POLYMER JR 400 (ex Meyhall) 1% HP101 (ex Olin) The pH of the composition was adjusted to 8.0 so that the HP101 was present in soluble form.

Claims (7)

1) An antimicrobial hair treatment composition comprising the following components: (a) an antimicrobial compound of the formula:

wherein X is an oxygen or sulfur moiety and R is e substituted or unsubstituted hydrocarbon radical having between 1 and 20 carbon atoms, with the proviso that R is other than chlorobenzyl, and R: is hydrogen or a cation selected from the group consisting of alkali metals, alkaline earth metals, ammonium ion and organic ammonium ions, or a compound of the formula:

wherein Y is an oxygen, sulfur, or NRr moiety wherein N. is nitrogen and R and R11 are independently each a substituted or unsubstituted hydrocarbon radical having between 1 and 20 carbon atoms, or a compound of the formula:

wherein Rtt and Rrv are independently either hydrogen or a substituted or unsubstituted hydrocarbon radicals having between 1 and 20 carbonatoms, with the proviso that either R or Rtl is a hydrocarbon radical; and (b) at least one surfactant, in which the pH of the hair treatment composition is at least 7, so that the antimicrobial compound is soluble in the hair treatment composition.

2) A composition according to claim 1, in which the antimicrobial compound is present in the composition in an amount from about 0.1 to about 38 by weight.

3) A composition according to any preceding claim, further comprising a deposition aid which is a cat ionic derivative of guar gum or a cationic polyacrylamide.

4) A composition according to any preceding claim. which is a shampoo composition, in which at the least one surfactant is selected from anionic, nonionic, amphoteric and zwitterionic surfactants, and mixtures thereof, in a total amount of from about 0.1 to about 50% by weight of the composition.

5) A composition according to any preceding claim, which further comprises a conditioning agent selected from volatile and non-volatile silicones.

6) A composition according to any preceding claim, which has a pH in the range of from 7.5 to 9.5.

7) A method of preparing an antimicrobial hair treatment composition which comprises mixing together the components (a) and (b) as are defined in Claim 1, and adjusting the pH of the resultant composition to at least 7, so that the antimicrobial compound of component (a) is soluble in the final hair treatment composition.