WO2015058942A1

WO2015058942A1 - A liquid disinfecting composition

Info

Publication number: WO2015058942A1
Application number: PCT/EP2014/071123
Authority: WO
Inventors: Anindya Dasgupta; Jasmeet Kaur Khokhar; Kalpana Kamalakar Nayak; Maya Treesa Saji; Jayashree Anantharam Vadhyar
Original assignee: Unilever NV; Conopco Inc
Current assignee: Unilever NV; Conopco Inc
Priority date: 2013-10-25
Filing date: 2014-10-02
Publication date: 2015-04-30
Anticipated expiration: 2016-04-25

Abstract

Disclosed invention relates to a liquid cleaning and disinfection composition. The invention more particularly relates to a composition for disinfection of skin or hard surfaces that provides synergistic antibacterial and antiviral efficacy. This is achieved through inclusion of an anionic surfactant SLES along with two carboxylic acids, the first being citric acid and the second chosen from malonic acid, malic acid or glycolic acid.

Description

A LIQUID DISINFECTING COMPOSITION

Field of the invention The invention relates to a liquid cleaning and disinfection composition. The invention more particularly relates to a composition for disinfection of skin or hard surfaces that provides synergistic antibacterial and antiviral efficacy.

Background of the invention

Liquid compositions for disinfecting and cleaning for personal care and for hard surfaces are known. Personal care includes cleansing and care of skin, hair and oral cavity. Hard surfaces include floors, walls, windows, doors, furniture, and table tops in various indoor and outdoor locations. Toilets and bathrooms are other places where germs proliferate and disinfection and cleaning compositions in liquid form are widely used. Other types of hard surfaces that are cleaned by such compositions include utensils and other articles found in households, offices and other public places.

Popular disinfecting / sanitizing actives like (i) bleaches and (ii) phenolics are known and widely used. They are sometimes considered harsh. It is an object of the present invention to develop mild disinfecting compositions for cleansing, disinfection and care for topical application and for hard surface cleaning and disinfection. Liquid hard surface cleaning compositions having a pH of 9 to 12 are known. Soaps for personal care and cleansing also have a high pH in a similar range. The present invention relates to a mild yet powerful disinfectant composition which is active at low pH of 2 to about 5. An especially useful aspect of the present invention is that the composition is very effective against virus which are inherently very difficult organisms to kill.

It is also known to include carboxylic acids in such compositions.

US6262038B (Altera, 1998) discloses a germicidal composition suitable for cleaning fruits, vegetables, skin and hair, includes a mixture of fruit acids and a surfactant. The surfactant may be an anionic surfactant (such as sodium lauryl sulfate), a sophorose lipid biosurfactant, or a combination of the two surfactants. The mixture of fruit acids may include citric acid, glycolic acid, lactic acid, malic acid and tartaric acid. The fruit acids are preferably present, in an aqueous solution, in a sufficient amount to produce a pH of about 2 to 6, for example 3.8 to 4.2.

US2006093570 (Reckitt) discloses a surface treatment composition, preferably for personal use, comprising at least one surfactant and at least two different organic acids and/or salts or organic acids, and wherein the total concentration of the organic acids and/or salts in the composition is at least 0.5 percent (w/v). The invention further extends to a method of treating a surface, preferably hair or skin, to remove dirt and to remove or inhibit microbial growth.

WO02/080668 A2 (Kimberly Clark Co) discloses that when one or more proton donating agents such as organic or inorganic acids are combined with an alkyl phosphate anionic surfactant comprised at least partially of a mono alkyl phosphate, numerous microorganisms are inactivated. In particular, it discloses antimicrobial action of a combination of acids, citric and malic, together with the mono alkyl phosphate. Also disclosed therein as a reference composition is a composition which has citric and malic, together with sodium lauryl sulphate and the combination has been shown to be effective against S. aureus and S. epidermidis and E.coli.

The journal article "Rhinovirus inactivation by nasal tissues treated with virucide", authored by Hayden et.al, and published in Antiviral Research Elsevier BV, NL, vol. 5, no. 2, 1 April 1985, discloses deactivation of colds virus by treating with citric acid, malic acid, and sodium lauryl sulfate.

The prior art WO'668 and the article authored by Hayden et.al., disclose antimicrobial effect of sodium lauryl sulphate together with citric and malic acids. In another journal article entitled "Profile of irritant patch testing with detergents: sodium lauryl sulfate, sodium laureth sulfate and alkyl polyglucoside" authored by H. Ujffler and Happle and published in Contact Dermatitis 2005, 48, 26-32, irritancy profile of the surfactant sodium lauryl sulphate (SLS) has been compared with another surfactant sodium lauryl ether sulphate (SLES) and the inference therein is that SLES is milder or irritant to a lesser extent as against SLS.

Further, there is a need for providing a composition that gives relatively more efficacious antimicrobial action, or an enhanced antimicrobial effect, when the cleaning period is relatively small, typically about 5 minutes or less, preferably lesser than 2 minutes and in many cases less than one minute or sometimes as low as 15 seconds or lesser. The present invention relates to the synergistic interaction between two selective carboxylic acids in the presence of one or more specific anionic surfactant to provide enhanced antibacterial and antiviral action over the above published compositions which can be formulated for hard-surface cleaning or personal care in a liquid composition.

The invention further relates to providing enhanced antibacterial and antiviral action which is effective over short time frames of less than about 5 minutes.

Summary of the invention

The present invention provides for a liquid cleaning and disinfecting composition having a pH from 2 to 5 comprising

(i) 1 to 20% anionic surfactant sodium lauryl ether sulphate (SLES);

(ii) 0.05 to 10% of a mixture of two carboxylic acids, the first carboxylic acid is citric acid and the second carboxylic acid is selected from malonic acid, malic acid, glycolic acid and mixtures thereof; and

(iii) 40 to 98% water.

Another aspect of the present invention provides for a method of disinfecting a surface comprising the steps of

(i) applying a composition of the invention on to a surface; and

(ii) rinsing the surface with a suitable solvent or wiping the surface with a suitable wipe. Detailed description of the invention

These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be utilised in any other aspect of the invention. The word "comprising" is intended to mean "including" but not necessarily "consisting of" or "composed of". In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all percentages are weight/weight percentages unless otherwise indicated.

Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word "about". Unless specified otherwise, numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated.

By a personal cleaning composition as used herein, is meant to include a composition for cleaning and disinfecting topical areas e.g. skin and/or hair of mammals, especially humans. Such a composition is generally a rinse off composition, and includes any product applied to a human body for also improving appearance, cleansing, odor control or general aesthetics. It is more preferably a rinse off product. The composition of the present invention is in the form of a liquid but may be modified to include a lotion, cream, foam or gel, or toner, or applied with an implement or via a face mask, pad or patch. "Skin" as used herein is meant to include skin on the face and body (e.g., neck, chest, back, arms, underarms, hands, legs, buttocks and scalp). The composition of the invention is also of relevance to applications on any other keratinous substrates of the human body other than skin e.g. hair where products may be formulated with specific aim of providing disinfection and cleaning. By a hard surface cleaning composition as used herein, is meant to include a composition for cleaning and disinfecting hard surfaces in the homes and other places like offices, restaurants, hotels, and public places like airports, bus stations, railways stations among other places. The hard surfaces in such places includes floors, walls, windows, doors, furniture, and table tops in the various indoor and outdoor locations abovementioned. Toilets and bathrooms are other places where such hard surface cleaning and disinfection composition are especially useful. Such a composition is generally a rinse off composition, and includes any product applied to such surfaces which may be applied and thereafter either rinsed off or wiped off in a few minutes if not in a few seconds. This is usually used for cleaning and disinfection but is also used for odour control. The composition of the present invention is in the form of a liquid but may be modified to include a lotion, cream, foam or gel.

The present invention relates to a liquid cleaning and disinfecting composition having a pH from 2 to 5. The pH is preferably in the range of 2.5 to 3.5.

The composition comprises 1 to 20% anionic surfactant sodium lauryl ether sulphate (SLES). The SLES is preferably sodium lauryl ether sulphate(n)EO, (where n is from 1 to 3). Sodium laureth sulfate, or sodium lauryl ether sulfate (SLES), is an anionic surfactant . It is added to many personal care products like soaps, shampoos, and toothpaste. SLES is an inexpensive and very effective foaming agent. Its chemical formula is

CH₃(CH2)ioCH2(OCH2CH2)_nOS0₃Na. Sometimes, the number represented by n is specified in the name, for example laureth-2 sulfate. The surfactant generally comprises a range of ethoxyl groups, where n denotes the mean. n= 3 is a very commonly used SLES. SLES is prepared by ethoxylation of dodecyl alcohol. The resulting ethoxylate is converted to a half ester of sulfuric acid, which is neutralized by conversion to the sodium salt. General structure of SLES is as follows:

In the present invention Sodium Laureth Sulfate (1 EO) with 70% purity has been used which was sourced from Galaxy Surfactants. SLES is present in 1 to 20% preferably 2 to 16%, further more preferably 2 to 14% by weight of the composition. We have determined that ethoxylated sodium lauryl sulphate i.e., SLES, provides much enhanced antimicrobial action as compared to its

unethoxylated counterpart i.e., SLS. While SLES has been known to be milder than SLS, the enhanced antimicrobial effect of SLES is a new technical effect. The composition of the invention comprises 0.05 to 10% of a mixture of two carboxylic acids, the first carboxylic acid is citric acid and the second carboxylic acid is selected from malonic acid, malic acid or glycolic acid. The first carboxylic acid is citric acid. Citric acid has the structure given below:

Citric acid is a weak organic acid with the formula C₆H₈0₇. Citric acid is a natural preservative. It is used to give a sour taste to foods and soft drinks. Citric acid is a commodity chemical and it is also used as a flavouring agent, and as a chelating agent. Citric acid is also widely used as a pH adjusting agent in creams and gels of all kinds. The second carboxylic acid is one of malonic acid, malic acid or glycolic acid or mixtures thereof. These acids have the structure given below: Malonic acid

Malic acid

It is particularly preferred that the first carboxylic acid is citric acid and the second carboxylic acid is malonic acid.

The first carboxylic acid citric acid is preferably present in 0.025% to 5% by weight of the composition. The second carboxylic acid is preferably present in 0.025% to 5% by weight of the composition. The mixture of carboxylic acid is present in 0.05 to 10%, preferably 0.1 to 5% by weight of the composition. It is preferred that the weight ratio of the first carboxylic acid and the second carboxylic acid is in the range of 1 :2 to 5:1. The composition comprises 40 to 98%, preferably 65 to 95% by weight water. The composition comprising SLES, the mixture of the two carboxylic acid and water is preferably used for personal care compositions for cleaning and disinfection of skin, hair and other topical surfaces of the human body. This is especially evidenced by data that indicates that this composition is found to give very good reduction of E.coli (transient flora), and S.aureus (skin pathogenic) bacteria in very short times of about 10 seconds. The composition of the invention preferably additionally comprises 1 to 20% of another anionic surfactant linear alkyl benzene sulphonate (LAS).

Linear alkylbenzene sulfonic acid (LAS) is the largest-volume synthetic surfactant available and used in various products because of its relatively low cost and good performance. The fact that it can be dried to a stable powder and its biodegradable nature makes it very attractive for use in large volume products. LAS is an anionic surfactant with molecules characterized by a hydrophobic and a hydrophilic group. LAS is generally a complex mixture of homologues of different alkyl chain lengths (C10 to C13 or C14). It contains an aromatic ring sulfonated at the para position and attached to a linear alkyl chain at any position with the exception of terminal one (1 -phenyl). The alkyl carbon chain typically has 10 to 14 carbon atoms and the linearity of the alkyl chains ranges from 87 to 98%. While commercial LAS consists of more than 20 individual components, the ratio of the various homologs and isomers, representing different alkyl chain lengths and aromatic ring positions along the linear alkyl chain, is relatively constant in currently produced products.

Various LAS are available according to the alkyl chain length, resulting in formulations for various applications. The starting material is ro prepare LAS is LAB (linear alkylbenzene). LAS is produced by the sulfonation of LAB with oleum in batch reactors. Other sulfonation alternative reagents are sulfuric acid, diluted sulfur trioxide, chlorosulfonic acid and sulfamic acid on falling film reactors. LAS are then neutralized to the desired salt. Surfactants are widely used in the industry needed to improve contact between polar and non-polar media such as between oil and water or between water and minerals. Linear alkylbenzene sulfonic acid is mainly used to produce household detergents including laundry powders, laundry liquids, dishwashing liquids and other household cleaners as well as in numerous industrial applications like as a coupling agent and as an emulsifier for agricultural herbicides and in emulsion polymerization.

Structure of one typical Sodium LAS is as follows:

LAS is commercially available at 95 - 96% purity from Galaxy Surfactants which has been used in the present invention. LAS is preferably present in 5 to 15% by weight of the composition.

It is preferred that the total amount of anionic surfactant in the composition is from 1 to 30% by total weight of the composition. When the composition comprises SLES and LAS it is especially preferred that the composition is useful for hard surface cleaning and disinfection purposes. This is especially so since this combination is found to inhibit growth of bacteria and virus generally present in such surfaces.

It is preferred that the composition comprises an amphoteric surfactant in addition to the anionic surfactant already present in the composition. The amphoteric surfactant is preferably a betaine.

Cocamidopropyl betaine (CAPB) is an organic compound derived from coconut oil and dimethylaminopropylamine. It is a zwitterion, consisting of both a quaternary ammonium cation and a carboxylate. CAPB is available as viscous pale yellow solution that is used as a surfactant in personal care products. The name reflects that the major part of the molecule, the lauric acid group, is derived from coconut oil.

Cocamidopropyl betaine is used as a foam booster in shampoos. It is a medium strength surfactant also used in bath products like hand soaps. It is also used in cosmetics as an emulsifying agent and thickener, and to reduce irritation generally caused by purely ionic surfactants. It also serves as an antistatic agent in hair conditioners, which most often does not irritate skin or mucous membranes. It also has antiseptic properties, making it suitable for personal sanitary products. It is compatible with other cationic, anionic, and nonionic surfactants. CAPB is obtained as an aqueous solution in concentrations of about 30%. Structure of CAPB is as follows:

Preferred betaines include alkyl betaines, alkyl amidopropyl betaines, and alkyl sulphobetaines (sultaines), wherein the alkyl and acyl groups have from 8 to 19 carbon atoms. Typical amphoteric surfactants for use in compositions of the invention include cocodimethyl sulphopropyl betaine, lauryl betaine, and cocamidopropyl betaine. A particularly preferred amphoteric is cocoamidopropyl betaine (CAPB). An especially useful combination of surfactants for personal care compositions like body wash and shampoos are a mixture of SLES and CAPB. When present, the amphoteric surfactant is preferably present in 0.1 to 5 wt%.

When the composition of the invention is formulated for hard surface cleaning compositions, the following optional ingredients may be included for providing additional consumer preferred properties to the liquid composition.

The compositions may contain other ingredients which aid in their cleaning

performance. For example, the composition may contain detergent builders such as nitrilotriacetates, polycarboxylates, water-soluble phosphates (especially ortho-, pyro-or poly-phosphates or mixtures thereof), zeolites and mixtures thereof in an amount up to 25%. If present, the builder preferably will form at least 0.1 % of the composition.

Metal ion sequestrants such as ethylenediaminetetraacetates, polyphosphonates (DEQUEST™-range) and the (ortho, pyro, poly) phosphoric acids/phosphates

(hereinafter collectively referred to as"phosphate"), and a wide variety of poly-functional organic acids (particularly citric acid) and salts, can also optionally be employed. The amount of such sequestrants, if present, is usefully between 0.05 and 5% by weight of the composition, preferably 0. 1 -1 %. A further optional ingredient for compositions according to the invention is a suds regulating material, which can be employed in compositions which have a tendency to produce excessive suds in use. One example of a suds regulating material is soap. Soaps are salts of fatty acids and include alkali metal soaps such as the sodium, potassium and ammonium salts of fatty acids containing from about 8 to about 24 carbon atoms, and preferably from about 10 to about 20 carbon atoms. Particularly useful are the sodium and potassium and mono-, di-and triethanolamine salts of the mixtures of fatty acids derived from coconut oil and ground nut oil. When employed, the amount of soap can form at least 0.005 wt%, preferably at least 0.1 % by weight of the composition.

A further example of a suds regulating material is a silicone oil. Where a hydrocarbon co-solvent is present at a sufficiently high level this may itself provide some or all of the desired antifoaming activity. Compositions according to the invention can also contain, in addition to the ingredients already mentioned, various other optional ingredients such as colorants, whiteners, optical brighteners, soil suspending agents, detersive enzymes, gel- control agents, freeze-thaw stabilisers, preservatives (for example 1 , 2-benzisothiazolin-3-one), and hydrotropes.

When the composition of the invention is formulated for personal care applications the following optional ingredients may be included.

Personal care compositions may comprise a skin lightening agent. The skin lightening agent is preferably chosen from a vitamin B3 compound or its derivative e.g. niacin, nicotinic acid, niacinamide or any other well known skin lightening agent. Most preferred skin lightening agent is niacinamide. Niacinamide, when used, is preferably present in an amount in the range of 0.1 to 10%, more preferably 0.2 to 5 wt% of the composition.

The personal care composition may preferably additionally comprise one or more UV sunscreens. The UV sunscreens may be inorganic or organic. A wide variety of organic sunscreen agents are suitable for use in combination with the essential ingredients of this invention. Most suitable organic sunscreen are 2-ethylhexyl-p- methoxycinnamate (as a UVB sunscreen agent) and/ or

butylmethoxydibenzoylmethane (as a UVA sunscreen agent). A safe and effective amount of sunscreen may be used in the compositions of the present invention. The composition preferably comprises from about 0.1 % to about 10%, more preferably from about 0.1 % to about 5% w/w of a sunscreen agent.

Useful inorganic sun-blocks are also preferably used in the present invention. These include, for example, zinc oxide iron oxide, silica, such as fumed silica, and titanium dioxide. Ultrafine titanium dioxide is preferably included. Ultrafine titanium dioxide are particles having an average particle size of less than 100 nm, preferably 70 nm or less, more preferably from 10 to 40 nm and most preferably from 15 to 25 nm. The total amount of sun block that is preferably incorporated in the composition according to the invention is from 0.1 to 5 wt% of the composition.

The composition according to the invention may also comprise other diluents. The diluents act as a dispersant or carrier for other materials present in the composition, so as to facilitate their distribution when the composition is applied to the skin.

Diluents other than water can include liquid or solid emollients, solvents, humectants, thickeners and powders.

The compositions of the present invention may include a wide range of other optional components. The CTFA Cosmetic Ingredient Handbook, Second Edition, 1992, which is incorporated by reference herein in its entirety, describes a wide variety of non- limiting cosmetic and pharmaceutical ingredients commonly used in the skin care industry, which are suitable for use in the compositions of the present invention.

Examples include: antioxidants, binders, biological additives, buffering agents, colorants, thickeners, polymers, astringents, fragrance, humectants, opacifying agents, conditioners, exfoliating agents, pH adjusters, preservatives, natural extracts, essential oils, skin sensates, skin soothing agents, and skin healing agents. A preferred embodiment of the composition has less than 1 % halogenated biocide e.g., chlorinated biocide. Further preferably it is less than 0.1 wt%.

According you another aspect of the present invention, there is provided a method of disinfecting a surface comprising the steps of (i) applying a composition of the invention on to a surface; and (ii) rinsing the surface with a solvent or wiping the surface with a wipe.

The solvent for rinsing the surface is preferably water but could also be a mixture of water and alcohol. The word rinsing herein includes the act of wiping the surface with a suitable wipe. Thus the surface e.g hand, face, body, oral cavity or any hard surface e.g. a utensil is first contacted with the composition of the invention. It is then rinsed preferably with sufficient amounts of water after a pre-determined period of time to remove any visible or sensory reside of the composition. Alternately an alcohol wipe or a water/alcohol impregnated wipe may be used to wipe the surface to be visibly free of the anti-microbial composition. The step of rinsing the substrate is preferably carried out less than five minutes, preferably less than two minutes, further more preferably less than a minute and in many cases less than fifteen seconds after the step of applying the composition on the substrate.

Yet another aspect of the present invention provides for use of the composition of the invention for enhanced antibacterial efficacy.

Yet another aspect of the present invention provides for use of the composition of the invention for enhanced antiviral efficacy.

The invention will now be demonstrated with the help of the following non-limiting examples. Examples

Examples A to D and Examples 1 to 3: Synergistic interaction between the surfactant sodium lauryl ether sulphate (SLES) and the carboxylic acid combinations claimed in the invention

Compositions as shown in Table-1 were prepared. The compositions were tested for antibacterial efficacy using the standard European Suspension Test protocol EN:1276 which is briefly described below.

One ml of bacterial culture was mixed with one ml of interfering substance of bovine serum albumin (BSA) solution. When the condition hereafter is mentioned as dirty (high soil) condition, BSA at 30 g/l was used. When the condition hereafter is mentioned as clean (low soil) condition, BSA at 3 g/l was used. Thereafter 8 ml of test solution was added. The test solutions were prepared in hard water at three different concentrations to include one concentration in the active range and one concentration in the non active range. The concentration of the test solution was 1 .25 times the required test concentration. The mixture was maintained at 20 ^°C for duration of contact time mentioned in each experiment. After this contact time, an aliquot was taken and immediately neutralized by adding to nine ml of D/E neutralizing solution. The number of bacteria in each sample was determined by plating on TSA agar. The plates were incubated at 37 ^°C for 48 hours. The plates with colonies >15 and <300 were counted. The cell numbers were converted to log counts. Reduction in viable count was calculated. The sample (at a particular concentration) was deemed to have passed the European Suspension test if there was a≥ 5 log reduction in the viable count demonstrated under the required test conditions.

The compositions in these set of experiments (diluted 1 :20 with hard water) were tested for antibacterial efficacy against a Gram negative bacteria (P. aeruginosa ATCC 15442) by maintaining a contact time of five minutes of the composition with the bacteria under dirty (high soil) condition for the anti-bacterial efficacy. The log reduction of bacteria for each of the compositions from a starting value of 7.3 log bacteria is shown in Table 1.

Note:

In the case of all the compositions (control as well as preferred) described in the tables below, only the acid(s) and the surfactant content has been shown in the table. Each composition had 80 wt% water and the compositions had other minor ingredients adding up to 100wt%. The pH of each composition was in the range of 2.5 to 3.5.

Table 1

Note: (^*) these examples are outside the scope of the invention

The data in Table -1 above indicates that compositions as per the invention (Examples 1 to 3) demonstrate high antibacterial efficacy and synergistic interaction over the individual components (Examples A to D).

Example E to H and 4 to 6: Experiments conducted with the compositions of Table -1 but with Gram +ve bacteria.

Compositions as in Table 1 were tested under similar conditions and analysed for residual bacteria using the same protocol but with a Gram positive bacteria (S. aureus ATCC 6538). The data is presented in Table 2. Table 2

Note: (^*) these examples are outside the scope of the invention

The data in Table 2 indicates that the synergistic interaction and high anti-bacterial efficacy is seen when used on Gram positive bacteria also.

Examples I to M and 7 to 9: Antibacterial efficacy of compositions at 10 seconds contact time

Compositions as shown in Table 3 were prepared. The efficacy was evaluated using the test method ASTM 2783-1 1 . The compositions were tested for efficacy against Gram negative bacteria (£. coli ATCC 10536) where the compositions were tested at 50% (1 :1 dilution in water) for a contact time of 10 seconds with the bacteria. The residual bacterial count was measured and the data is summarized in Table 3.

Table-3

Lactic Citric Malic

SLES, Malonic Glycolic Log

Example acid, acid, acid,

wt% acid, wt% acid, wt% reduction wt% wt% wt%

I^* 2.0 - - - - - 0.1

J^* 2.0 0.04 - - - - 0.3

K^* 2.0 - 0.04 - - - 0.8

L^* 2.0 - - 0.04 - - 3.0

M^* 2.0 0.04 0.04 - - 1 .5

7 2.0 - 0.04 0.04 - - 7.3

8 2.0 - 0.04 - 0.04 - 7.3

9 2.0 0.04 - - 0.04 7.3 Note: (^*) these examples are outside the scope of the invention

The data in Table 3 above indicates that at very low concentrations and at very low contact times, the compositions of the invention (Examples 7 to 9) demonstrate high and synergistic efficacy as compared to individual components. Further, the efficacy of the carboxylic acid combinations claimed in the present invention is shown to be superior to other carboxylic acid combinations (e.g., with Lactic acid in Example J and M). Examples N and 10, 1 1 : Improved efficacy in using SLES as compared to other surfactant sodium lauryl sulphate (SLS).

Compositions as shown in Table 4 were prepared and the efficacy was tested using the standard European Suspension Test protocol EN:1276 against Gram -ve bacteria (P. aeruginosa ATCC 15442) under clean (low soil condition) when the compositions were diluted 1 :10 with water and the contact time was 1 minute. The data on log reduction of the bacteria is shown in Table 4.

Table 4

Note: (^*) this example is outside the scope of the invention

The data in Table 4 indicates the superior anti-bacterial efficacy of the composition of the invention Example 10 which comprises the surfactant claimed in the invention

(SLES) as compared to a composition that comprises another surfactant SLS as used in US6262038B (Altera, 1998) and also WO'668 and the article authored by Hayden et.al,. Examples P and 12 to 14: Improved efficacy of the compositions of the invention as against prior art compositions

Compositions as shown in Table 5 were prepared and the efficacy tested using the standard European Suspension Test protocol EN:1276 against Gram negative bacteria (P. aeruginosa) under dirty (high soil) condition when the compositions were diluted 1 :20 with water and the contact time was five minutes. LAS in the table refers to sodium alkyl benzene sulphonate. The data on log reduction of the bacteria is shown in Table 5.

Table 5

Note: (^*) this example is outside the scope of the invention

The data in Table 5 indicates that compositions as per the present invention (Examples 12 to 14) provides vastly improved antibacterial efficacy as compared to that disclosed in the past viz. Example P as in US2006093570 (Reckitt). Examples Q, R and 15 to 17: Various other compositions

Compositions as shown in Table 6 were prepared and the efficacy tested using the standard European Suspension Test protocol EN:1276 against Gram +ve bacteria (S. aureus ATCC 6538) under dirty (high soil) condition when the compositions were diluted 1 :30 with water and the contact time was one minute. The data on log reduction of the bacteria is shown in Table 6. Table 6

Note: (^*) these examples are outside the scope of the invention

In the Table 6 above, fruit acid is a mixture of 4 parts citric acid, 15 parts glycolic acid, 30 parts lactic acid, 1 part malic acid and 1 part tartaric acid.

The data in Table 6 above indicates that compositions as per the present invention (Examples 15 to 17) provides vastly improved antibacterial efficacy as compared to compositions outside the invention (Examples Q and R). Example Q indicates that combination of SLS with citric and malic acid [and also some more fruit acids] does not provide antimicrobial effect anywhere comparable to that obtained with combination of SLS with citric and malic acid or citric and malonic acid.

Examples S, T, 18: Various other compositions

Compositions as shown in Table 7 were prepared and the efficacy tested using the standard European Suspension Test protocol EN:1276 against Gram +ve bacteria (S. aureus ATCC 6538) under dirty condition when the compositions were diluted 1 :60 with water and the contact time was five minute. The data on log reduction of the bacteria is shown in Table -7. Table 7

Note: (^*) these examples are outside the scope of the invention

The data in Table 7 indicates that composition as per the invention (Example 18) gives vastly superior antibacterial efficacy as compared to a combination of citric acid and lactic acid with surfactant SLES (Example T) which has been used in the past and is outside the scope of the present invention.

Example U,V and Example 19: Experiments conducted with the compositions of Table 7 but with Gram -ve bacteria (P. aeruginosa ATCC 15442)

Compositions as in Table- 7 were tested under similar conditions and analysed for residual bacteria using the same protocol but with a Gram negative bacteria (P.

aeruginosa ATCC 15442). The compositions however were diluted to 1 :30 dilution. The data is presented in Table 8. Table 8

Note: (^*) these examples are outside the scope of the invention

The data in Table 8 indicates that a compositions as per the invention (Example 19) provides much enhanced antibacterial efficacy as compared to those outside the invention (Examples U and V). Example W and 20: Antiviral efficacy of the compostion as per the invention

Compositions as in Table 9 were prepared and tested for anti-viral efficacy (against Feline calcivirus used at 4.5 log) after a dilution of the composition of 1 :10 with water. The procedure for measuring the anti-viral efficacy is given below:

Determination of Virucidal Activity:

A standard EST protocol (EN 14476) was followed for the evaluation of activity of antiviral actives in suspension test. Antiviral activity of actives was tested in clean conditions. Clean conditions:

To create clean conditions, 0.3 g of bovine albumin fraction V was dissolved in 100 ml of water and sterilized by passing the solution through a 0.2 μηη filter).

Preparation of test mixture:

To prepare the test mixture, 100 μΙ of interfering substance (hard water or clean water or dirty water) was pipette into a suitable container, followed by addition of 100 μΙ of test virus suspension. To this, 800μΙ of product test solution was added. At the end of chosen contact time period, 100 μΙ of the test mixture was added to resin column, centrifuged in a microspin column (735 xg, 2 minutes) and the elutant was diluted upto 10^"6 in ice cold virus growth medium. The infectivity of each dilution was measured by TCID50 using the Karber formula. The effect of clean conditions, on virus was also determined by infectivity.

Titration of Virus:

Monolayers of cells were grown in 96-well tissue-culture plates (Costar) at 37 °C in an atmosphere of 95% air and 5% carbon dioxide (C0₂). Tenfold dilutions of virus suspension were prepared in virus growth medium. One hundred microlitres of each dilution was added to five replicate wells in 96-well tissue-culture plates. Cell controls were included on each plate. Plates were incubated at 37 °C in an atmosphere of 95% air/ 5% C0₂. Cultures were observed daily for viral cytopathic effect for a period of seven days after which they were discarded.The virus titre was calculated by TCID50 (Tissue culture infective dose ) using the Karber formula.

The formula is as follows: Negative logarithm of the 50 % end point = Negative logarithm of the highest virus concentration used - [(Sum of % affected at each dilution / 100 - 0.5) x (log of dilutions)] The log reduction of the virus for the compositions is summarized in Table -9.

Table -9

Note: (^*) this example is outside the scope of the invention

The data in Table 9 indicates that a composition as per the invention (Example 20) provides for vastly improved anti-viral efficacy as compared to a conventional clean composition.

Claims

1. A liquid cleaning and disinfecting composition having a pH from 2 to 5

comprising:

(i) 1 to 20% anionic surfactant sodium lauryl ether sulphate (SLES);

(iii) 40 to 98% water.

2. A composition as claimed in claim 1 additionally comprising 1 to 20% of anionic surfactant linear alkyl benzene sulphonate (LAS).

3. A composition as claimed in claim 1 or 2 wherein the first carboxylic acid is citric acid and the second carboxylic acid is malonic acid.

4. A composition as claimed in any one of the preceding claims comprising 0.1 to 5% of carboxylic acid.

5. A composition as claimed in any one of the preceding claims comprising 1 to 30% of total anionic surfactant.

6. A composition as claimed in any one of the preceding claims additionally comprising an amphoteric surfactant.

7. A composition as claimed in claim 6 wherein said amphoteric surfactant is a betaine.

8. A composition as claimed in claim 6 or 7 wherein said amphoteric surfactant is present in 0.1 to 5 wt%.

9. A composition as claimed in any one of the preceding claims comprising less than 1 % halogenated biocide.

10. A composition as claimed in claim 9 wherein said halogenated biocide is present in less than 0.1 wt%.

1 1. A method of disinfecting a surface comprising the steps of :

(i) applying a composition as claimed in any one of the preceding claims on to a surface; and

(ii) rinsing the surface with a suitable solvent or wiping the surface with a suitable wipe.

12. A method as claimed in claim 1 1 wherein said step of rinsing or wiping the surface is carried out less than 5 minutes after the step of applying the composition on the surface.

13. Use of a composition as claimed in any one of the preceding claims 1 to 10 for enhanced antibacterial efficacy.

14. Use of a composition as claimed in any one of the preceding claims 1 to 10 for enhanced antiviral efficacy.