BACKGROUND ART It is known that infection is spread via skin contact through the transmission of pathogenic microorganisms. Hitherto, in order to reduce the presence of such organisms it has been known to scrub the skin with a solution containing a surfactant followed by application of an antiseptic.

In recent years it has been suggested that it would be desirable to combine the washing and disinfectant actions in a single operation by providing a composition comprising both an antimicrobial agent and a surfactant. It has been found however that many antimicrobial agents such as chlorhexidine [N,N'-bis(4-chlorophenyl)- 3,12- diimino 2,4,1 3-tetraazatetradecanediimidamide] digluconate and other chlorhexidine salts are incompatible with anionic surfactants, and are reduced in their antimicrobial activity by nonionic surfactants, thus requiring addition of more antimicrobial agent in order to retain sufficient biocidal activity at the amount of surfactant required for satisfactory foam formation.

In particular, US 3,855,140 assigned to Imperial Chemical Industries describes a skin cleansing composition comprising a soluble salt of chlorhexidine in combination with a polyoxyethylenepolyoxypropylene block copolymer. In order to obtain sufficient sudsing of the polymer it is necessary to use high proportions of the surfactant in amounts of the order of 20-25%. High amounts of chlorhexidine are consequently required to maintain the desired antimicrobial activity. Such high amounts are undesirable as it is known that surfactants may affect the skin adversely by defatting, and causing in combination with biocides such as chlorhexidine, irritation to the skin. Further the ingredients of the composition can be costly.

It would be desirable therefore to provide a composition in which the amount of antimicrobial agent and surfactant is reduced whilst maintaining sufficient antimicrobial activity and sudsing ability.

In this regard, in order to provide such a composition, WO 95/09605 teaches one to combine a phenolic disinfectant with an alkylpolyglucoside surfactant. As indicated in that patent however, such compositions although showing good biocidal activity against most microorganisms, are incapable of disinfecting surfaces contaminated by the microorganism Pseudomonas aeruginosa to which the compositions are inactive.

It is an object of the invention to substantially ameliorate the disadvantages of the prior art.

DESCRIPTION OF THE INVENTION According to a first aspect of the invention, there is provided an antiseptic cleansing composition comprising an antimicrobial agent, an effective amount of an alkylpolysaccharide surfactant, at least one alkyl alcohol and at least one aryl alcohol.

According to a second aspect of the invention there is provided a method of decontaminating surfaces contaminated with bacteria including the Pseudomonas microorganism, which method comprises contacting the surface with the disinfectant cleansing composition of the first aspect.

Typically the cleansing composition comprises an inert carrier, and optionally other additives.

The alkylpolysaccharide surfactants are also known in the art as alkylpolyglucosides, however, for the purposes of the following discussion, the surfactant will be termed an alkylpolysaccharide.

Preferably, the content of the surfactant present in the composition does not exceed 6% w/v.

Preferably the alkylpolysaccharide is an alkylpolysaccharide of the formula:

wherein n is an integer between 5 and 19, and m is an integer between 1 and 3.

In the above formula the surfactant alkyl polysaccharide shown contains glucose units, however the invention is not limited thereto and other sugar units can be substituted for one or more of the glucose units. Other sugar units which might be included in the alkylpolysaccharide include maltose, arabinose, xylose, mannose, galactose, gulose, idose, talose, allose, altrose, sucrose, fructose, sorbose, levulose, lactose, allulose, tagatose, alloheptulose, sedoheptulose, glucoheptulose, mannoheptulose, guloheptulose, idoheptulose, galactoheptulose, taloheptulose and derivatives thereof.

Suitable antimicrobial agents include chlorhexidine and its salts; dichlorophene, other chlorophenol derivatives such as p-chloro-m-xylenol, chlorophene and o-phenylphenol, 2,4,4-trichloro-2-hydroxy-diphenylether (triclosan); octenidindihydrochloride (CH3 -(CH2)7-NHON-(CH2),0-NO-NH(CH2)7-CH2 or any other salt thereof and quatemary ammonium compounds.

Suitable salts of chlorhexidine include the gluconate, isethionate, formate, acetate, glutamate, succinamate, monodiglycolate, dimethanesulfonate, lactate, diisobutyrate or the glucoheptonate salts.

Preferably the antimicrobial agent has a water solubility of at least 0.001% w/v at ambient temperature.

When the antimicrobial agent is chlorhexidine digluconate it is used in an amount preferably not exceeding 4.5% w/v. When the antimicrobial agent is 2,4,4- trichloro-2-hydroxydiphenylether (triclosan) it is used in an amount preferably not exceeding 3% w/v.

The alkyl alcohol is preferably a lower alkyl alcohol (herein defined as an alcohol having less than 6 carbon atoms) such as ethanol, iso or n-propanol, most preferably the alkyl alcohol is isopropanol or n-propanol. The alcohol content preferably does not exceed 70% w/v. When the composition is in an aqueous carrier (for example for use in hand washing) the alcohol is desirably iso or n-propanol or a combination thereof and is preferably present in an amount of from 3 to 10% w/v, most preferably 4 to 8% w/v. When the composition is an alcoholic solution (for example for a rapid cleaning self-drying solution) the alkyl alcohol will be preferably be 55-75% w/v.

The aryl alcohol is preferably a berizylalcohol, phenylethylalcohol, phenoxyethanol, phenoxypropanol or a chlorinated derivative thereof. For application to skin, phenoxyethanol and phenoxypropanol are preferred. Preferably the aryl alcohol is present in an amount not exceeding 3% w/v.

An inert carrier can be used - for example water or a lower alcohol such as ethanol.

The composition may further comprise one or more of the following integers: (a) a solubilising agent for example propylene glycol, a hydrotrope or mixtures thereof. Suitable hydrotropes include urea, cumene sulphonate, toluene sulfonate, xylenesulphonate and the ethanolamine salts of citric and other hydroxycarboxylic acids.

(b) a foaming agent such as an alkylaminooxide, alkylmono or diethanolamides. Examples of foaming agents are lauryl or cocodiethanolamide or monoethanolamide condensates or the lauryl or cetyl dimethylamineoxides.

(c) viscosity modifiers such as cellulose derivatives, guar resins and carbopol resins.

(d) preservatives such as imidazolidinyl, urea derivatives (Germabenes), methyl or propyl parabens (p-hydroxy benzoic esters).

(e) other conventional additives such as colouring agents, fragrances, antioxidants, emolients, moisturisers, stabilising agents and thickeners such as carboxymethylcellulose.

(f) optionally, additional surfactants including amphoteric surfactants, anionic surfactants and nonionic surfactants. Suitable additional surfactants include quaternary ammonium compounds or a small amount of a high foaming anionic surfactant such as laurylethoxysulfonate, sarcosinates, sodium laurylethersulphate.

The additional ingredients are selected to avoid possible incompatibility with any of the other ingredients of the composition and especially with regard to the antimicrobial agents.

The pH of the composition is typically adjusted to pH 5 to 7, most preferably 5.5 but is not limited to this pH. When chlorhexidine is used as the antimicrobial agent, a pH greater than 8 should be avoided to prevent precipitation of the chlorhexidine free base. Most organic acids compatible with the composition, such as lactic, acetic, citric and gluconic acids, preferably gluconic acid, can be used to adjust the pH.

The term "comprising" as herein used is used in an inclusive sense, that is to say in the sense of"including" or "containing". The term is not intended in an exclusive sense ("consisting of" or "composed of').

BEST MODES FOR CARRYING OUT THE INVENTION The following examples illustrate preferred embodiments of the present invention. They should not be construed as limiting.

It will also be understood by those skilled in the art that while the present invention is described herein with reference to a concentrate, such a concentrate could be diluted prior to sale (for example to 55%) or use.

EXAMPLES Example I - ComDarative comDosition in accordance with WO 95109605 Sodium laurylsulfate (100%) 4.67% w/v Alkylpolysaccharide (100%) 3.92% w/v Coconut Betaine (100%) 0.90% w/v Triclosan 0.49% w/v Propylene glycol 0.254% w/v Glycerine 0.254% w/v

Sodium chloride 0.49% w/v Citric acid up to 10% w/v Water to 100% by volume Example II- Comparative Commercial Antibacterial Skin Cleanser Containing 2.0% (Triclosan) Full Composition Unknown) Example III -Comparative Composition of Commercial Antiseptic Surgical Scrub Chlorhexidine Gluconate (CHG) 4.0% w/v Nonionic Surfactant* (100%) 25.00% w/v Lauryl Dimethylamineoxide (100%) 2.60% w/v Water to 100.0% by volume (formula as per published data (Manuf. Chemist, October 1973, p. 25-27 and disclosed in US Patent 3 855 140) *polyoxyethylene/polyoxypropylene block copolymer PLURONIC F87 (BASF, Germany).

Example IV - Inventive Composition containing Triclosan Same composition as Example 1 to which n-propanol 5.0% w/v and phenoxyethanol 1% w/v have been added.

Example V - Inventive Composition containing Triclosan Same composition as Example 1 to which 5.0% w/v n-propanol and 1% w/v phenoxyethanol have been added and the triclosan increased to 1% w/v.

Example VI - Inventive Composition Containing Chlorhexidine Gluconate Chlorhexidine Gluconate (CHG) 2.0% w/v Alkylpolysaccharide* (100%) 4.00% w/v Cocodiethanolamide (100%) 2.00% w/v Propylene Glycol 2.0% w/v Isopropanol 8.0% w/v Phenoxyethanol 2.0% w/v Water to 100% by volume *OramixTM NS10 55% w/v (Sepic SA, France).

Example VII - Inventive Compositions Containing Chlorhexidine Gluconate Chlorhexidine gluconate (CHG) 1.0% w/v Alkylpolysaccharide* (100%) 4.00% w/v Cocodiethanolamide (100%) 0.80% w/v Propylene glycol 2.0% w/v n-propanol 6.0% w/v Phenoxypropanol 1.0% w/v Water to 100.0% by volume <BR> <BR> <BR> * Any commercial alkylpolysaccharide can be used such as Plantaren TM<BR> commercial alkylpolysaccharide can be used such as Plantaren 2000 (Henkel) or AtlasTM G73500 (ICI).

Example VIII- inventive Composition Containing Triclosan Triclosan 1.0% w/v Alkylpolysaccharide* (100%) 4.00% w/v Sodium 2 laurylethersulfate (100%) 0.20% w/v Cocodiethanolamide (100%) 2.00% w/v Isopropanol 8.0% w/v Propylene Glycol 10.0% w/v Preservative** 1.0% w/v Phenoxyethanol 2.0% w/v Water to 100.0% by volume <BR> <BR> TM<BR> *Oramix NS 12 (Sepic SA, France) **GermabeneTM II 0.2% w/v Example IX - Inventive Composition Containing Triclosan Triclosan 1.0% w/v Alkyl polysaccharide* (100%) 4.00% w/v Sodium 2 laurylethersulphate (100%) 0.25% w/v Sodium cumene sulfate (100%) 4.00% w/v Ethyl alcohol 4.0% w/v n-propanol 4.0% w/v Phenoxyethanol 1.5% w/v Water to 100% by volume *Any commercial alkylpolysaccharide can be used such as Plantaren 2000 (Henkel) or AtlasTM G73500 (ICI).

Example X - Inventive Composition Containing Triclosan Triclosan 1.00% w/v Alkylpolysaccharide (100%) 2.75% w/v Cocodiethanolamide (100%) 0.80% w/v Sodium xylene sulphonate (100%) 4.00% w/v Isopropanol 8.0% w/v Propylene glycol 2.0% w/v Phenoxyethanol 1.0% w/v Carboxymethyl cellulose 0.6% w/v Phenoxypropanol 1.0% w/v Water to 100.0 by volume % Example XI - Inventive Composition Containing Dichlorophene Dichlorophene 1.5% w/v Alkylpolysaccharide (100%) 4.00% w/v Sodium 2 laurylethersulfate (100%) 0.20% w/v Cocodiethanolamide (100%) 2.00% w/v Isopropanol 5.0% w/v Phenoxyethanol 1.0% w/v Water to make 100.0% by volume Example XII - Inventive Composition Containing Dichlorophene

Dichlorophene 1.5% w/v Alkylpolysaccharide (100%) 4.00% w/v Sodium 2 laurylethersulphate (100%) 0.50% w/v Cocodiethanolamide ( 100%) 1.00% w/v Ethanol 5.0% w/v Phenoxyethanol 1.0% w/v Water to make 100.0% by volume adjust pH to 7.0 - 7.2 with triethanolamine.

Suspension tests were performed (in accordance with European Standard CEN/TC2 1 6/WG IN) in the presence of a number of organisms. The results are shown in the following table: TABLE I - SUSPENSION TESTS RESULTS EXPRESSED AS: log reduction Test temperature: 23"C; Contact time: 60 seconds Neutralising Medium: Tween80 100 g/L, Lecithin 50 g/L, Histidine 1 g/L ..,. cCnccntraLon Neat Neat Concentration Neat Conlact Time (sccs) \ 60 1 60 60 | 60 l l l l Fonnujations: Comparative Example 10.49% wiv | NO j NG >2 | >2 Triclosan Inventive Example 1V ova9% wtv l NG - NG l NG | NG Triclosan Comparative Example 1l 23C | >2 | >2 1 >2 1 >2 Triclosan Inventive Example v l.Oe/ w/v NO NO NO NO Triclosan Comparative Example 1112% wlv NO 3.8 NO 3.9 CHO Inventive Example Vl 2.0% wlv | NG j NG t NG NO CHG l l l l l Inoculum Level \ 2.5 x 108 Level 2.8 x lOX | NG: Means NO GROWTH

Suspension tests were also conducted for the composition of Example X (1.0% w/v Triclosan). The results were as follows: Microbicidal Results Suspension test - 30 sec contact/con. 75% Expressed as a Log reduction of microorganisms.

Microorganism Inoculum level Reduction S. aureus ATTC 6538 Log 6.8 > 5.8 E. coli ATTC 11229 Log 6.9 > 5.9 PS aeruginosa ATTC 15442 Log 7.0 > 6.0 P. mirabilia ATTC 14153 Log 6.8 > 6.0 Compositions according to the invention have the same or greater effectiveness with respect to biocidal activity and are less toxic, at much lower concentrations of the antimicrobial agent in comparison with conventional prior art compositions.

In preferred embodiments, the use of an alkylpolysaccharide surfactant in amounts below 6% (w/v), the amount of triclosan can be successfully reduced from 1.0% to 0.5% (w/v) with substantially no loss in biocidal activity. Surprisingly the amount of chlorhexidine can be reduced 4% to 2% (w/v) whilst maintaining good biocidal activity and foaming properties.

Further, by use of alkylpolysaccharides in amounts as low as 2% it is possible to obtain sufficient foaming skin cleansing properties not obtainable with other conventional surfactants. Further, the known interference with the antimicrobial properties of biocides with surfactants is considerably reduced.

Further, by the inclusion of an alkyl and aryl alcohol combination, the compositions of the invention are effective against the pseudomonas microorganism.

The invention is a significant and important improvement on the art as taught in US 3,855,140 as illustrated by the fact that, while the composition of US Patent 3,855,140 showed no activity against Pseudomonas, the compositions ofthe present invention are effective against Pseudomonas at concentrations containing as low as 0.49% triclosan.

Compositions according to the invention are especially suitable for skin and hand disinfection, surface disinfection, impregnation of sponges, woven and non- woven textiles and the like.

The composition of the invention is suitable for cleansing any object. The composition of the invention is particularly suitable for cleansing hands in clinical situations and before surgery but can also be used for cleansing inanimate objects such as surgical instruments.