WO2018065190A1

WO2018065190A1 - Personal wash disinfectant liquid

Info

Publication number: WO2018065190A1
Application number: PCT/EP2017/073390
Authority: WO
Inventors: Ajit Manohar AGARKHED; Mohini Anand Bapat; Nikita TOMAR
Original assignee: Unilever NV; Conopco Inc
Current assignee: Unilever NV; Conopco Inc
Priority date: 2016-10-07
Filing date: 2017-09-18
Publication date: 2018-04-12
Anticipated expiration: 2019-04-07
Also published as: CN109803532A; BR112019005645A2; MX2019003774A; ZA201901673B

Abstract

An antimicrobial composition comprising: 0.01 to 15 wt% of a first quaternary ammonium composition comprising didecyl dimethyl ammonium chloride or a derivative thereof; and 0.01 to 15 wt% of a second quaternary ammonium composition comprising benzalkonium chloride (BKC) or a derivative thereof; wherein the antimicrobial composition comprises at most 10% wt of C2 to C3 monohydric alcohols; and wherein the additive concentration of non-ionic and anionic surfactant in the antimicrobial composition is less than 5 wt% based on the weight of the antimicrobial composition; and wherein the antimicrobial composition further comprises a pH indicator.

Description

PERSONAL WASH DISINFECTANT LIQUID

Technical Field

The present invention relates to an antimicrobial composition. The present invention more particularly relates to an antimicrobial composition suitable as a personal wash disinfectant liquid.

Background of the invention

People try to take good care of the external surface of their bodies as well as those of their pets to enable good overall health. Specific skin related issues that people care about include good skin health free of infections, good skin tone and skin hygiene. Skin hygiene is generally achieved by keeping them free of infections.

The skin is the biggest organ of our body and it acts as a protective layers against bacteria and other harmful germs. Everyday our body is assaulted by harmful chemicals, dirt and grime. Washing and bathing are the most important ways of maintain good health and protecting oneself from infections, illnesses and ailments. Staying clean at all times helps to keep germs away and prevent major diseases that they may cause. Therefore, it is of utmost importance and highly desirable that the daily bathing routine is supplemented by a regime that leaves the skin free of infection causing agents such as microbes.

A major problem in many geographies is use of hard water for bathing. This hard water is high in mineral content and is formed when water percolates through deposits of limestone and chalk which are largely made up of calcium and magnesium carbonates. The water hardness (i.e., high concentration of divalent cations) reduces the rate of kill of most of the disinfectants used in bath water because divalent cations (e.g., magnesium, calcium) in the hard water interact with the disinfectant to form insoluble precipitates. WO1995031958 (LONZA INC.) discloses that certain combinations of substituted imidazoline- based amphoterics and quaternary ammonium compounds show markedly reduced irritation profile in addition to providing excellent cleaning detergency. Moreover, it has further been found that certain substituted imidazoline amphoteric surfactants in combination with didecyl dimethyl ammonium chloride (DIDAC) show unexpected synergistic irritation reduction compared to that observed when the quaternary is an ADBAC type. This allows the formulation of disinfectants and sanitizers with the favored antimicrobial agent while at the same time affording the optimum reduction in irritation potential.

Therefore, there is a need for a disinfectant liquid that provides the bathing water, even when used in hard water, with antimicrobial properties for a holistic cleaning and disinfectant effect. The object of the present invention is therefore to provide for a synergistic antimicrobial composition that provides the desired antimicrobial action even after diluting with water and which provides a visual cue of change in colour on dilution.

Summary 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.

First aspect of the present invention provides an antimicrobial composition comprising: a. 0.01 to 15 wt% of a first quaternary ammonium composition comprising didecyl dimethyl ammonium chloride or a derivative thereof; and

b. 0.01 to 15 wt% of a second quaternary ammonium composition comprising benzalkonium chloride (BKC), or a derivative thereof;

wherein the antimicrobial composition comprises at most 10% wt of C2 to C3 monohydric alcohols; and

wherein the additive concentration of non-ionic and anionic surfactant in the antimicrobial composition is less than 5 wt% based on the weight of the antimicrobial composition; and

wherein the antimicrobial compostion further comprises a pH indicator.

Another aspect of the present invention provides for 0.01 to 15 wt% of a first quaternary ammonium composition comprising didecyl dimethyl ammonium chloride or a derivative thereof; and 0.01 to 15 wt% of a second quaternary ammonium composition comprising benzalkonium chloride (BKC) or a derivative thereof; and a pH indicator as a disinfectant for use in personal hygiene.

Another aspect of the present invention provides a method of personal wash, the method comprising steps of: a. diluting the antimicrobial composition according to the first aspect to at most to 5000 times to obtain a diluted antimicrobial composition, and

b. washing the surface of skin with the antimicrobial diluted composition resulting from step a.

Another aspect of the present invention provides a disinfectant kit for personal wash, the kit comprising: a. an antimicrobial composition according to the first aspect,

b. a dispensing container, and

c. a set of instructions.

Another aspect of the present invention provides a method of manufacture of the composition according to the first aspect, the method comprising: a. adding the first quaternary ammonium composition and the second quaternary ammonium composition; and

b. adding pH indicator to obtain the antimicrobial composition.

Detailed description of the invention

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". 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". 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.

The present invention provides an antimicrobial composition comprising: a. 0.01 to 15 wt% of a first quaternary ammonium composition comprising didecyl dimethyl ammonium chloride or a derivative thereof; and b. 0.01 to 15 wt% of a second quaternary ammonium composition comprising benzalkonium chloride (BKC) or a derivative thereof;

wherein the antimicrobial composition further comprises a pH indicator. Quaternary Ammonium Composition The disclosed embodiments comprise a quaternary ammonium composition comprising a quaternary ammonium compound or other compound having the same effects. Quaternary ammonium compounds are ammonium compounds in which all four of the ammonium's hydrogen atoms have been replaced by organic groups. The quaternary ammonium compounds of the present disclosure have the following basic structure:

wherein R1 , R2, R3, and R4 are organic substituent groups that provide the quaternary ammonium compound with antimicrobial properties and X is any anion that makes the compound sufficiently water soluble to allow the compound to form an antimicrobial solution. With reference to this general formula, R1 , R2, R3, and R4 are typically independently selected from the group consisting of all alkyl groups and aryl groups.

The antimicrobial activity of quaternary ammonium compounds may be related to their ability to disrupt the cell membranes of microbes. It is suspected that positively charged quaternary ammonium ions are attracted to the net negative charge on the surface of most microbes. The preferred quaternary ammonium compounds of the present disclosure release a positively charged quaternary ammonium ion in solution.

The preferred quaternary ammonium compounds of the present disclosure have at least one substituent group containing from 6 to 24 carbon atoms, typically from 8 to 20 carbon atoms; or, alternatively, two substituent groups that form an aliphatic or aromatic ring including the nitrogen atom. The disclosed embodiments may contain an effective amount of a single quaternary ammonium compound or mixtures of two or more quaternary ammonium compounds. Examples of quaternary ammonium compounds suitable for the disclosed invention include without limitation: n-alkyl dimethyl benzyl ammonium chloride, n-alkyl dimethyl ethylbenzyl ammonium chloride, n-alkyl dimethyl 3,4-dichlorobenzyl ammonium chloride, dioctyl dimethyl ammonium chloride, didecyl dimethyl ammonium chloride, cetyl pyridinium chloride, etc., and combinations thereof.

First Quaternary Ammonium Composition

The composition of the present invention comprises 0.01 to 15 wt%, more preferably 0.05 to 10 wt% and most preferably 1 to 8 wt% of a first quaternary ammonium composition by weight of the antimicrobial composition. Preferably, the first quaternary ammonium composition comprises didecyl dimethyl ammonium chloride DDAC in the range of 0.01 to 15 wt% by weight of the antimicrobial composition, preferably 0.05 to 10 wt% and most preferably 1 to 8 wt% by weight of the antimicrobial composition. It is preferable that 70 to 100 wt%, more preferably 80 to 100 wt% and most preferably 90 to 100 wt% of the total first quaternary ammonium composition is DDAC based on the weight of the total first quaternary ammonium composition.

Didecyl Dimethyl Ammonium Chloride (DDAC) is a known disinfectant used in many biocidal formulations. It has the followin structure:

Didecyl Dimethyl Ammonium Chloride

In a preferable aspect the first quaternary ammonium composition may further comprise other quaternary ammonium compounds such as n-alkyl dimethyl benzyl ammonium chloride, n-alkyl dimethyl ethylbenzyl ammonium chloride, n-alkyl dimethyl 3,4-dichlorobenzyl ammonium chloride, dioctyl dimethyl ammonium chloride, cetyl pyridinium chloride, etc., or derivatives, mixtures and combinations thereof.

Second Quaternary Ammonium Compound The present invention also comprises 0.01 to 15 % by weight of a second quaternary ammonium composition comprising benzalkonium chloride (BKC) or a derivative thereof.

The second quaternary ammounium composition may additionally comprise benzathonium chloride (BEC). In a preferable aspect the second quaternary ammonium composition may further comprise other quaternary ammonium compounds such as n-alkyl dimethyl 3,4-dichlorobenzyl ammonium chloride, dioctyl dimethyl ammonium chloride, cetyl pyridinium chloride, didecyl dimethyl ammonium chloride etc., or derivatives, mixtures and combinations thereof.

Benzalkonium Chloride (BKC) Benzalkonium chloride (BKC) also known as alkyldimethylbenzylammonium chloride. It is known to be used as a cationic surfactant and as a biocide. It has the following structure:

n = 8, 10, 12, 14, 16, 18

The amount of BKC is preferably in the range of 0.01 to 15 wt%, more preferably 0.05 to 10 wt% and most preferably 1 to 8 wt% by weight of the antimicrobial composition.

It is preferable that BKC consists 70 to 100 wt%, more preferably 80 to 100 wt% and most preferably 90 to 100 wt% of the total second quaternary ammonium composition based on the weight of the total second quaternary ammonium composition. Benzethonium chloride

Benzethonium chloride (BEC) also known as hyamine which is a quaternary ammonium compound. It is known for its disinfectant properties and having the following structure:

BEC is known for its antiseptic and anti-infective properties. It has been known to be used in cosmetic and toiletries compositions.

The amount of BEC is preferably in the range of 0.01 to 15 wt%, more preferably in the range of 0.05 to 10 wt% and most preferably in the range of 1 to 8 wt% by weight of the antimicrobial composition.

It is preferable that BEC consists 70 to 100 wt%, more preferably 80 to 100 wt% and most preferably 90 to 100 wt% of the total second quaternary ammonium composition based on the weight of the total second quaternary ammonium composition. More particularly the present invention provides an antimicrobial composition comprising: a. 0.01 to 15 wt% of a first quaternary ammonium composition comprising didecyl dimethyl ammonium chloride; and

b. 0.01 to 15 wt% of a second quaternary ammonium composition benzalkonium chloride (BKC);

wherein the antimicrobial composition further comprises a pH indicator.

It is preferred that the ratio by weight of the antimicrobial composition of first quaternary ammonium composition to the second quaternary ammonium composition in the antimicrobial composition ranges from 10:1 to 1 :10, more preferably from 8:1 to 1 :8 and most preferably from 5:1 to 1 :5.

It is further preferred that the ratio of DDAC to the second quaternary ammonium composition in the antimicrobial composition ranges from 10:1 to 1 :10, more preferably from 8:1 to 1 :8 and most preferably from 5:1 to 1 :5. It is further preferred that the ratio of DDAC to the BKC in the antimicrobial composition ranges from 10:1 to 1 :10, more preferably from 8:1 to 1 :8 and most preferably from 5:1 to 1 :5.

Water hardness (i.e., high concentration of divalent cations) reduces the rate of kill of most of the disinfectants because divalent cations (e.g., magnesium, calcium) in the hard water interact with the disinfectant to form insoluble precipitates.

Water Hardness

Hardness is caused by compounds of calcium and magnesium, and by a variety of other metals. General guidelines for classification of waters are: 0 to 60 mg/L (milligrams per liter) as calcium carbonate is classified as soft; 61 to 120 mg/L as moderately hard; 121 to 180 mg/L as hard; and more than 180 mg/L as very hard.

The present inventors have surprisingly found that the first and second quaternary ammonium compounds act synergistically to improve antimicrobial efficacy even in hard water conditions, which is not possible with any single quaternary ammonium compound taken in isolation. The hard water conditions are defined as 120 to 180 mg/L (milligrams per liter) of calcium carbonate and most preferably,≥ 180 mg/L mg/L (milligrams per liter) of calcium carbonate.

C2 to C3 monohydric alcohols

The present invention is most preferably an aqueous antimicrobial composition having C2 to C3 monohydric alcohols at most 10 wt% by the weight of the antimicrobial composition. The antimicrobial composition of the present invention is preferably 'substantially free' and more preferably 'essentially free' of C2 to C3 alcohols, and most preferably 'completely free' of C2 to C3 alcohols, which find their most common use in sanitizers. The term 'substantially free' means less than 1 wt%, 'essentially free' means less than 0.01 wt% and 'completely free' means less than 2.0x10^"6 wt%. In a highly preferred aspect of the present invention, the amount of C2 to C3 alcohols ranges from 0 to 5 wt%, more preferably from 0.0001 to 5 wt% and most preferably from 0.01 to 3 wt% based on the weight of the antimicrobial composition. It is preferred that the antimicrobial composition comprises at most 10 wt% of C2 to C3 alcohols, more preferably at most 8 wt%, even more preferably at most 5 wt%, even more preferably at most 2 wt%, even more preferably at most 1 % and most ideally 0%, in the order of preference, 0% being the ideal most preference. C2 monohydric alcohol is ethanol and C3 monohydric alcohol is propanol. The term C2 to C3 monohydric alcohols includes ethanol, propanol and derivatives such as isopropyl alcohol (isopropanol), n-propanol.

Non-ionic, anionic surfactant and amphoteric surfactants The additive concentration of non-ionic and anionic surfactant in the antimicrobial composition is less than 5% based on the weight of the antimicrobial composition. It is preferable that the antimicrobial composition of the present invention is 'substantially free' and more preferably 'essentially free' of non-ionic and anionic surfactant, and most preferably 'completely free' of non-ionic and anionic surfactant, which find their most common use in sanitizers. The term 'substantially free' means less than 1 wt%, 'essentially free' means less than 0.01 wt% and 'completely free' means less than 2.0x 10^"6 wt%. In a highly preferred aspect of the present invention, additive concentration of non-ionic and anionic surfactant ranges from 0 to 5 wt%, more preferably from 0.0001 to 5 wt% and most preferably from 0.01 to 3 wt% based on the weight of the antimicrobial composition. It is preferred that the antimicrobial composition comprises at most 5 wt% of non-ionic and anionic surfactant, more preferably at most 4 wt%, even more preferably at most 3 wt%, even more preferably at most 2 wt%, even more preferably at most 1 wt% and most ideally 0 wt%, in the order of preference, 0 wt% being the ideal most preference.

The antimicrobial composition of the present invention is preferably 'substantially free' and more preferably 'essentially free' of amphoteric surfactants, and most preferably 'completely free' of amphoteric surfactants, which find their most common use in sanitizers. The term 'substantially free' means less than 1 wt%, 'essentially free' means less than 0.01 wt% and 'completely free' means less than 2.0x 10^"6 wt%. In a highly preferred aspect of the present invention, the amount of amphoteric surfactant ranges from 0 to 5 wt%, more preferably from 0.0001 to 5 wt% and most preferably from 0.01 to 3 wt% based on the weight of the antimicrobial composition. It is preferred that the antimicrobial composition comprises at most 10 wt% of amphoteric surfactants, more preferably at most 8 wt%, even more preferably at most 5 wt%, even more preferably at most 2 wt%, even more preferably at most 1 wt% and most ideally 0 wt%, in the order of preference, 0 wt% being the ideal most preference. Water

The present antimicrobial composition is preferably an aqueous type of antimicrobial composition having water at least 70 wt%, more preferably at least 80 wt% and most preferably at least 85 wt%, based on the weight of the antimicrobial composition. The suitable ranges of water in the antimicrobial composition are from 70 to 99 wt%, more preferably from 80 to 98 wt% and most preferably from 85 to 97.5 wt% based on the weight of the antimicrobial composition. Chelating agent

It is preferable that the antimicrobial compositions of the present invention include chelating agent in the range from 0.01 wt% to 3 wt%, more preferably from 0.01 to 2 wt% and most preferably from 0.05 to 1.5 wt% by weight of the antimicrobial composition. It is most preferred that the chelating agent comprises, most preferably is, a polydentate ligand. The antimicrobial composition preferably comprises polydentate ligand in an amount of from 0.01 wt% to 3 wt%, more preferably from 0.01 to 2 wt% and most preferably from 0.05 to 1.5 wt% based on the weight of the antimicrobial composition.

Preferred chelating agents are as follows (names followed by their abbreviation in parenthesis):

Ethylene Diamine Tetra Acetic acid (EDTA), Diethylene Triamine Penta Acetic acid (DTPA), Ethane-1 -hydroxy-1 ,1-diphosphonate (EHDP), Ethylene Diamine-N,N'-Disuccinate (EDDS), Nitrilo Triacetic Acid (NTA), Sodium Imino Disuccinate (IDS), Ethylene Glycol-bis-(2- aminoethyl)-N,N,N', N'-Tetra Acetic acid (EGTA), Methyl Glycine Diacetic Acid (MGDA), N-(2- hydroxyethyl) Ethylene Diamine Ν,Ν',Ν'-Thacetic acid) (HEDTA), Ethylene Diamine Tetra Methylene Phosphonic acid (EDTMP), Diethylene Thamine-Penta-Methylene Phosphonic acid (DTPMP), Glutamic acid-N,N-Diacetic Acid (GLDA), Cyclohexane-1 ,2-Diamine-N,N,N',N'- Tetra-Acetic Acid (CDTA), 1 ,3-Propylenediamine Tetra-Acetic Acid (PDTA), Ethylene Diamine Triacetic Acid (EDTA), L-hydroxy Imino Disuccinic acid (L-IDS), Trisodium N-Carboxyethyl Imino Succinate (CEIS), Citric Acid, Sodium Thpolyphosphate (STP), Thethylene Tetramine Hexaacetic Acid (TTHA). Other preferred chelating agents are Trisodium Ethylene Diamine Disuccinate, Tetra-sodium-lmino disuccinate, Glutamic acid-Ν,Ν diacetic acid tetra sodium salt, 2-hydroxyethyl iminodiacetic acid, Sodium salt (disodium ethanol diglycinate), Tetrasodium 3- hydroxy-2,2 imino disuccinate, Trisodium methylglycine diacetic acid, L- Aspartate-N,N-diacetic acid tetrasodium salt. The more preferred chelating agents are salt of Ethylene Diamine Tetra Acetic acid (EDTA) and salt of Diethylene Thamine Penta Acetic acid (DTPA). Preferred salts of EDTA are disodium Ethylene Diamine Tetra Acetic acid and tetrasodium Ethylene Diamine Tetra Acetic acid. Preferred salt of DTPA is the pentasodium Diethylene Thamine Penta Acetic acid. Method

The present invention provides a method of disinfecting the surface of skin, the method comprising the steps of: Diluting the antimicrobial composition to at most to 5000 times, and washing the skin with the diluted antimicrobial composition. It is most preferable that the diluted antimicrobial composition is allowed to sit for at least 5 minutes before it is used for washing the skin.

EH

It is preferred that the pH of the antimicrobial composition ranges from 2 to 7, more preferably from 3 to 6 and most preferably from 3.5 to 6. Dilution

It is highly preferred that the intended use of the present antimicrobial composition for personal wash is most suitable after diluting with water. The dilution is at most 1 part of the antimicrobial composition with 5000 parts of water, it is most preferred that the dilution is at most 1 part of the antimicrobial composition with 3000 parts of water and most preferably the dilution is at most 1 part of the antimicrobial composition with 2000 parts of water.

It was a unique finding by the inventors of the invention that the antimicrobial composition of the present invention is effective even at very high levels of dilution. pH indicator

It is preferred that the antimicrobial composition has a pH ranging from 2 to 7, preferably 2 to 6 and is preferably used in diluted form with water. Therefore, it is preferable to provide a pH indicator indicating that the pH of the diluted antimicrobial composition is close to the neutral pH- 7 which is most suitable for use as personal wash. The pH of the antimicrobial composition after dilution with water is preferably in the range of 7 to 9, more preferably in the range of 7 to 8.5 most preferably in the range of 7 to 8. The colour change is observed over a wide range of dilution i.e over 1 :500 to 1 :3000. The conditions over which the actual experiments were carried out at was at 1 :2000.

The pH indicator is therefore preferable for a visual indication that the antimicrobial composition is suitably diluted and is good for use as personal wash. There is also a wide array of suitable pH indicators available to the skilled artisan. Preferably, the protonated and deprotonated forms of the pH indicator have large differences in extinction coefficients (for example, 200 vs 18,000 M^'On^"1 at 404 nm for 4-nitrophenol) which allows for good sensitivity. Suitable pH indicators include but are not limited to chlorophenol red (pK_a 6.0) useful for screening at a pH of approximately 6, 4-nitrophenol (pK_a 7.2) useful for screening at a pH of approximately 7, phenol red (pK_a 8.0) useful for screening at a pH of approximately 8, and thymol blue (pK_a 9.2) useful for screening at a pH of approximately 9. Other suitable indicators may be identified in the Merck Index (The Merck Index, 10th ed., Merck & Co., Rahway, NJ, 1983), Indicators (ed. By E. Bishop, Pergamon Press, New York, 1972), or the Sigma / Aldrich Handbook related to dyes and indicators (The Sigma-Aldrich Handbook of Stains, Dyes and Indicators' by Floyd J. Green, published by Aldrich Chemical Company in 1990, Milwaukee, Wisconsin). In addition, the skilled artisan would be aware of many other such suitable pH indicators that may be utilized in practicing the present invention. Those skilled in the art would recognize that the present assay could be utilized to assay enzyme activity at many different pH ranges utilizing specific pH indicator/buffer combinations. As the majority of hydrolases have maximal activity near neutral pH, an assay designed for use at pH 7.2 could use, for example, 4-nitrophenol as a pH indicator due to the similarity of its pK_a (7.15) (The Merck Index, 10th ed., Merck & Co., Rahway, NJ, 1983, p. 950.) If the pK_a of an indicator is not known, the pK_a could be ascertained by measuring the midpoint of the pH change as standardized base is added. It should also be understood that the pKa may shift under different assay conditions, for example, cosolvent and ionic strength may change the pK_a values and that the skilled artisan should take this into account. Exemplary buffer-indicator combinations include but are not limited to the following: chlorophenol red (pK_a 6.0) and MES (2-[N-morpholino]ethanesulfonic acid, pK_a 6.1 ) for use at a pH of approximately 6; 4-nitrophenol (pK_a 7.2) and BES (N,N-bis[2-hydroxyethyl]-2- aminoethanesulfonic acid, pK_a 7.15) for use at a pH of approximately 7; phenol red (pK_a 8.0) and EPPS (N-[2-hydroxylethyl]piperazine-N'-[3-propanesulfonic acid], pK_a 8.0) for use at a pH of approximately 8; thymol blue (pK_a 9.2) and, CHES (2-[N-cyclohexylamino]ethane-sulfonic acid, pK_a 9.3) for use at a pH of approximately 9. In a preferred embodiment, the buffer-indicator combination is BES (K,N-bis[2-hydroxyethyl]-2-aminoethanesulfonic acid) and 4-nitrophenol (pK_a 7.2) because the pK_a of BES (7.15) (Beynon, et al. Buffer Solutions, The Basics, IRL Press, Oxford, .1996, p. 72) is the same as that of 4-nitrophenol. The skilled artisan would be aware of many other such suitable buffer-pH indicator combinations that may utilized in practicing the present invention. It is highly preferred to use a pH indicator that provides a visual cue at a neutral pH.

In this respect the present inventors have carried out several experiments with various indicators that help the consumers have a visual cue of change of colour on dilution. The preferred pH indicators, the pH of the antimicrobial compositions prepared using them, the pH on dilution, the colour of the antimicrobial composition and the colour of the composition on dilution with water is give in Table -A below.

It is preferred that the pH indicator used in the antimicrobial composition is selected from cresol red, bromothymol blue, phenol red or cresol purple, more preferably from cresol red, bromothymol blue, or phenol red, and most preferably is bromothymol blue.

Kit

The present invention provides a disinfectant kit for providing personal washing, comprising the antimicrobial composition of the present invention, a dispensing container; and a set of instructions. It is highly preferable that the dispensing container comprises a nozzle, which is preferably capable of dispensing the antimicrobial composition in a drop wise manner. It is most preferable that the dispensing container contains the antimicrobial composition of the present invention.

Container

The present invention provides a dispensing container containing the antimicrobial composition of the present invention. The antimicrobial compositions may be provided in bottles, pump dispensers, tubes, sachets, or other packaging suitable for the product form. It is highly preferred that the antimicrobial composition of the invention is packaged in a dispensing container. The dispensing container most preferably comprises a nozzle, which is preferably capable of dispensing the antimicrobial composition in a drop wise manner.

Use The present invention also provides the use of the antimicrobial composition of the present invention as a personal wash disinfectant liquid.

The present invention also provides use of benzalkonium chloride and didecyl dimethyl ammonium chloride as a disinfectant for use as a personal wash disinfectant liquid.

A preferred use of the antimicrobial composition of the present invention is for preparing a disinfecting aqueous solution by diluting the antimicrobial composition to at most to 5000 times with water.

The present invention provides use of 0.01 to 15 wt% of a first quaternary ammonium composition comprising didecyl dimethyl ammonium chloride or a derivative thereof; and 0.01 to 15 wt% of a second quaternary ammonium composition comprising benzalkonium chloride (BKC) or a derivative thereof; and a pH indicator as a disinfectant for use in personal hygiene.

The present invention provides use of 0.01 to 15 wt% of a first quaternary ammonium composition comprising didecyl dimethyl ammonium chloride; and 0.01 to 15 wt% of a second quaternary ammonium composition comprising benzalkonium chloride (BKC); and a pH indicator as a disinfectant for use in personal hygiene. The present invention provides use of the antimicrobial composition for providing disinfection in hard water.

The present invention provides use of 0.01 to 15 wt% of a first quaternary ammonium composition comprising didecyl dimethyl ammonium chloride or a derivative thereof; and 0.01 to 15 wt% of a second quaternary ammonium composition comprising a compound selected from benzalkonium chloride (BKC; and a pH indicator as a disinfectant in hard water.

The present invention provides use of 0.01 to 15 wt% of a first quaternary ammonium composition comprising didecyl dimethyl ammonium chloride; and 0.01 to 15 wt% of a second quaternary ammonium composition comprising benzalkonium chloride (BKC) and a pH indicator as a disinfectant in hard water. Manufacture

The present invention also provides a method of manufacture of the antimicrobial composition, the method comprising adding the first quaternary ammonium composition and the second quaternary ammonium composition most preferably in water; and adding a pH indicator to obtain the antimicrobial composition.

The present invention also discloses a use of the antimicrobial composition of the present invention as disclosed above for improved antimicrobial benefit. More particularly the present invention discloses the use of a first quaternary ammonium composition comprising didecyl dimethyl ammonium chloride and a second quaternary ammonium composition comprising benzalkonium chloride (BKC) and a pH indicator in a topical antimicrobial composition for synergistic antimicrobial benefit.

Synergistic antimicrobial benefit preferably means the antimicrobial composition of the invention is able to provide significantly better antimicrobial benefit when the individual component of the present antimicrobial composition used alone. The inventors surprisingly found that, after application of the antimicrobial composition of the present invention the residual microbes on the surface are significantly less. Therefore the antimicrobial composition of the present invention able to provide antimicrobial benefits. The preferred intended use of the antimicrobial composition of the present invention is non-therapeutic and/or cosmetic.

Optional Ingredients If desired, the formulations may optionally include a detersive surfactant in addition to the non- ionic surfactant. Such detersive surfactants include, for example, anionic, zwitterionic and/or non-ionic surfactants.

Examples of anionic surfactants suitable for use herein include, but are not limited to, ammonium lauryl sulfate, ammonium laureth sulfate, triethylamine lauryl sulfate, triethylamine laureth sulfate, triethanolamine lauryl sulfate, triethanolamine laureth sulfate, monoethanolamine lauryl sulfate, monoethanolamine laureth sulfate, diethanolamine lauryl sulfate, diethanolamine laureth sulfate, lauric monoglyceride sodium sulfate, sodium lauryl sulfate, sodium laureth sulfate, potassium laureth sulfate, sodium lauryl sarcosinate, sodium lauroyl sarcosinate, potassium lauryl sulfate, sodium trideceth sulfate, sodium methyl lauroyl taurate, sodium lauroyl isethionate, sodium laureth sulfosuccinate, sodium lauroyl sulfosuccinate, sodium tridecyl benzene sulfonate, sodium dodecyl benzene sulfonate, sodium lauryl amphoacetate and mixtures thereof.

The anionic surfactant may be, for example, an aliphatic sulfonate, such as a primary C8-C22 alkane sulfonate, primary C8-C22 alkane disulfonate, C8-C22 alkene sulfonate, C8-C22 hydroxyalkane sulfonate or alkyl glyceryl ether sulfonate.

Zwitterionic surfactants suitable for use herein include, but are not limited to derivatives of aliphatic quaternary ammonium, phosphonium, and sulfonium compounds, in which the aliphatic radicals can be straight or branched chain, and wherein one of the aliphatic substituents contains from about 8 to about 18 carbon atoms and one substituent contains an anionic group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. Illustrative zwitterionic surfactants are coco dimethyl carboxymethyl betaine, cocoamidopropyl betaine, cocobetaine, oleyl betaine, cetyl dimethyl carboxymethyl betaine, lauryl bis-(2-hydroxyethyl) carboxymethyl betaine, stearyl bis-(2-hydroxypropyl) carboxymethyl betaine, oleyl dimethyl gamma-carboxypropyl betaine, lauryl bis-(2-hydroxypropyl)alpha-carboxyethyl betaine, and mixtures thereof. The sulfobetaines may include stearyl dimethyl sulfopropyl betaine, lauryl dimethyl sulfoethyl betaine, lauryl bis-(2-hydroxyethyl) sulfopropyl betaine and mixtures thereof.

Suitable nonionic surfactants include the reaction products of compounds having a hydrophobic group and a reactive hydrogen atom, for example aliphatic alcohols or fatty acids, with alkylene oxides, especially ethylene oxide either alone or with propylene oxide. Examples include the condensation products of aliphatic (Cs-Cis) primary or secondary linear or branched alcohols with ethylene oxide, and products made by condensation of ethylene oxide with the reaction products of propylene oxide and ethylenediamine. Other so-called nonionic surfactant compounds include long chain tertiary amine oxides, long chain tertiary phosphine oxides and dialkyi sulphoxides. Other suitable nonionics include mono or dialkyi alkanolamides or alkyl polyglucosides. Also useful are the alkyl polysaccharides. Nonlimiting examples of nonionic surfactants include coco mono or diethanolamide, coco mono isopropanolamide, and coco di glucoside. Examples of useful nonionic surfactants include the polyethylene, polypropylene, and polybutylene oxide condensates of alkyl phenols, fatty acid amide surfactants, polyhydroxy fatty acid amide surfactants, alkyl cthoxylate surfactants, alkanoyi glucose amide surfactants, and alkylpolyglycosides. Specific examples of suitable nonionic surfactants include alkanolamides such as cocainide DEA, cocamide MEA, cocamide MIPA, lauramide DEA, and lauramide MEA, sorbitan lauratc, sorbitan distcaratc, fatty acids or fatty acid esters such as lauric acid, and isostearic acid, fatty alcohols or ethoxylated fatty alcohols such as laiiryl alcohol, lauicth-4, laureth-7, laiireth-9, laureth-40, ti^'ideceth alcohol, Cn- 15 pareth-9, C12- 13 Pareth-3, and C14-15 Pareth-1 1 , alkylpolyglucosides such as decyl glucoside, lauryl glucoside, and coco glucoside. The nonionic surfactant may also be a carbohydrate or sugar-based surfactant, ethers, esters or amides, such as alkyl (poly)saccharides and alkyl (poly)saccharide amides.

The nonionic surfactant may also be a sugar amide, such as a polysaccharide amide. Specifically, the surfactant may be one of the lactobionamides described in U.S. Patent No. 5,389,279 to Au et al. or it may be one of the sugar amides described in Patent No. 5,009,814 to Kelkenberg.

Other surfactants which may be used are described in U.S. Patent No. 3,723,325 to Parran Jr. and alkyl polysaccharide nonionic surfactants as disclosed in U.S. Patent No. 4,565, 647 to Llenado.

The formulations typically include one or more skin benefit agents. The term "skin benefit agent" is defined as a substance which softens or improves the elasticity, appearance, and youthfulness of the skin (stratum corneum) by either increasing its water content, adding, or replacing lipids and other skin nutrients, or both, and keeps it soft by retarding the decrease of its water content. Included among the suitable skin benefit agents are emollients, including, for example, hydrophobic emollients, hydrophilic emollients, or blends thereof. Useful skin benefit agents include the following: (a) silicone oils and modifications thereof such as linear and cyclic polydimethylsiloxanes; amino, alkyl, alkylaryl, and aryl silicone oils; (b) fats and oils including natural fats and oils such as jojoba, soybean, sunflower, rice bran, avocado, almond, olive, sesame, persic, castor, coconut, and mink oils; cacao fat; beef tallow and lard; hardened oils obtained by hydrogenating the aforementioned oils; and synthetic mono, di and triglycerides such as myristic acid glyceride and 2-ethylhexanoic acid glyceride; (c) waxes such as carnauba, spermaceti, beeswax, lanolin, and derivatives thereof; (d) hydrophobic and hydrophilic plant extracts; (e) hydrocarbons such as liquid paraffin, petrolatum, microcrystalline wax, ceresin, squalene, pristan and mineral oil; (f) higher fatty acids such as lauric, myristic, palmitic, stearic, behenic, oleic, linoleic, linolenic, lanolic, isostearic, arachidonic and poly unsaturated fatty acids (PUFA); (g) higher alcohols such as lauryl, cetyl, stearyl, oleyl, behenyl, cholesterol and 2-hexydecanol alcohol; (h) esters such as cetyl octanoate, myristyl lactate, cetyl lactate, isopropyl myristate, myristyl myristate, isopropyl palmitate, isopropyl adipate, butyl stearate, decyl oleate, cholesterol isostearate, glycerol monostearate, glycerol monolaurate, glycerol distearate, glycerol tristearate, alkyl lactate, alkyl citrate and alkyl tartrate; (i) essential oils and extracts thereof such as mentha, jasmine, camphor, white cedar, bitter orange peel, ryu, turpentine, cinnamon, bergamot, citrus unshiu, calamus, pine, lavender, bay, clove, hiba, eucalyptus, lemon, starflower, thyme, peppermint, rose, sage, sesame, ginger, basil, juniper, lemon grass, rosemary, rosewood, avocado, grape, grapeseed, myrrh, cucumber, watercress, calendula, elder flower, geranium, linden blossom, amaranth, seaweed, ginko, ginseng, carrot, guarana, tea tree, jojoba, comfrey, oatmeal, cocoa, neroli, vanilla, green tea, penny royal, aloe vera, menthol, cineole, eugenol, citral, citronelle, borneol, linalool, geraniol, evening primrose, camphor, thymol, spirantol, penene, limonene and terpenoid oils; (j) lipids such as cholesterol, ceramides, sucrose esters and pseudo-ceramides as described in European Patent Specification No. 556,957; (k) sunscreens such as octyl methoxyl cinnamate (Parsol MCX) and butyl methoxy benzoylmethane (Parsol 1789); (I) phospholipids; and (m) anti-aging compounds such as alpha-hydroxy acids and beta-hydroxy acids. Preferably, the antimicrobial composition may have sunscreen. Any sunscreen that can be suitably used with the base may be added. Both, UVA and UVB sunscreens may preferably be added.

The antimicrobial composition of the invention preferably comprises a UV- A sunscreen which is a dibenzoylmethane or its derivatives. Preferred dibenzoylmethane derivatives are selected from 4-tert-butyl-4'-methoxydibenzoylmethane, 2-methyldibenzoylmethane, 4-methyl- dibenzoylmethane, 4-isopropyldibenzoyl-methane, 4-tert-butyldibenzoylmethane, 2,4- dimethyldibenzoylmethane, 2,5-dimethyldibenzoylmethane, 4,4'-diisopropyl- dibenzoylmethane, 2-methyl-5-isopropyl-4'-methoxydibenzoylmethane, 2-methyl-5-tert-butyl- 4'-methoxy-dibenzoyl methane, 2,4-dimethyl-4'- methoxy dibenzoylmethane or 2,6-dimethyl- 4-tert-butyl-4'-methoxy-dibenzoylmethane. The most preferred dibenzoylmethane derivative is 4-tert.-butyl-4'-methoxydibenzoylmethane. The antimicrobial composition of the invention preferably comprises 0.1 to 10%, more preferably 0.2 to 5%, further more preferably 0.4 to 3%, by weight dibenzoylmethane or a derivative thereof based on total weight of the antimicrobial composition and including all ranges subsumed therein. The antimicrobial composition preferably comprises a UV-B organic sunscreen selected from the class of cinnamic acid, salicylic acid, diphenyl acrylic acid and derivatives thereof.

Illustrative non-limiting example of UV-B sunscreens which are commercially available and useful for inclusion in the antimicrobial composition of the invention are OctisalateTM, HomosalateTM, NeoHelipanTM, OctocryleneTM, OxybenzoneTM or Parsol MCXTM. The UV-B sunscreen is most preferably 2-ethyl-hexyl-4-methoxy cinnamate which is commercially available as Parsol MCX. The UV-B organic sunscreen is preferably included in 0.1 to 10%, more preferably 0.1 to 7 % by weight of the antimicrobial composition. It has been observed that presence of an organic UV-B sunscreen like 2-ethyl-hexyl-4-methoxy cinnamate causes further rapid degradation of the UV-A dibenzoylmethane sunscreen in the presence of UV radiation. The presence of the rosmarinic acid ester antimicrobial compound is found to be very efficacious in stabilizing the antimicrobial composition even when UV-B sunscreens are present. 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.

Skin benefit agents commonly account for up to 30wt.% of the liquid soap formulation, with levels of from 0 to 25wt.%, more particularly from 0 to 20wt%, being typical of the levels at which those skin benefit agents generally known as "emollients" are employed in many of the subject formulations. Preferred skin benefit agents include fatty acids, hydrocarbons, polyhydric alcohols, polyols and mixtures thereof, with emollients that include at least one C12 to C18 fatty acid, petrolatum, glycerol, sorbitol and/or propylene glycol being of particular interest in one or more embodiments.

Other optional ingredients include water soluble/dispersible polymers. These polymers can be cationic, anionic, amphoteric or nonionic types with molecular weights higher than 100,000 Dalton. They are known to increase the viscosity and stability of liquid personal cleansing formulation, to enhance in-use and after-use skin sensory properties, and to enhance lather creaminess and lather stability. When present, the total amount of such polymers commonly ranges from 0.1 to 10% by weight of the personal cleansing formulation. Examples of water soluble or dispersible polymers include the carbohydrate gums such as cellulose gum, microcrystalline cellulose, cellulose gel, hydroxyethyl cellulose, hydroxypropyl cellulose, sodium carboxymethylcellulose, methyl cellulose, ethyl cellulose, guar gum, gum karaya, gum tragacanth, gum arabic, gum acacia, gum agar, xanthan gum and mixtures thereof; modified and nonmodified starch granules and pregelatinized cold water soluble starch; emulsion polymers such as Aculyn® 28, Aculyn® 22 or Carbopol ©Aqua SF1 ; cationic polymer such as modified polysaccharides including cationic guar available from Rhone Poulenc under the trade name Jaguar C13S, Jaguar C14S, Jaguar C17, or Jaguar C16; cationic modified cellulose such as UCARE Polymer JR 30 or JR 40 from Amerchol; N-Hance^® 3000, N-Hance^® 3196, N-Hance^® GPX 215 or N-Hance^® GPX 196 from Hercules; synthetic cationic polymer such as Merquat^® 100, Merquat^® 280, Merquat^® 281 and Merquat^® 550 sold by Nalco; cationic starches such as StaLok^® 100, 200, 300 and 400 sold by Staley Inc.; cationic galactomannans such as Galactasol^® 800 series by Henkel, Inc.; Quadrosoft^® LM-200; and Polyquaternium-24. Also suitable are high molecular weight polyethylene glycols such as Polyox^® WSR-205 (PEG 14M), Polyox^® WSR-N-60K (PEG 45), and Polyox® WSR-301 (PEG 90M).

Preservatives/antimicrobials can desirably be incorporated into the personal cleansing formulations of this invention to protect against the growth of potentially harmful microorganisms. Suitable traditional preservatives for formulations of this invention are alkyl esters of para-hydroxybenzoic acid. Other preservatives/ antimicrobials which have more recently come into use include hydantoin derivatives, propionate salts, and a variety of quaternary ammonium compounds. Among the preservatives/antimicrobials of particular interest are phenoxyethanol, methyl paraben, propyl paraben, imidazolidinyl urea, sodium dehydroacetate and benzyl alcohol. Other preservatives of particular interest are dimethyloldimethylhydantoin (Glydant XL1000), parabens, sorbic acid, thymol and terpineol to name a few (with combinations of thymol and terpineol as described, for example, in U.S. Patent Application Publication No. 201 1/02231 14 incorporated herein by reference, being of particular interest in one or more embodiments). The preservatives/antimicrobials should be selected having regard for the use of the formulation and possible incompatibilities between the preservatives and other ingredients. Preservatives are preferably employed in amounts ranging from 0.01 to 2% by weight of the personal cleansing formulation.

Additional optional ingredients which may be present in the subject personal cleansing formulations are, for example: fragrances; pH adjusters; antioxidants, for example, butylated hydroxytoluene (BHT) and the like; stabilizers; suds boosters, such as for example, coconut acyl mono- or diethanol amides; ionizing salts, such as, for example, sodium chloride and sodium sulfate, and other ingredients such as are conventionally used in liquid soap formulations. The total amount of such additional optional ingredients is typically from 0 to 10% by weight, more particularly from 0.1 to 5% by weight, based on the total weight of the personal cleansing formulation. Appropriate solubilizing excipients may be used for incorporating the optional ingredients, benefit agents and fragrances.

A variety of other optional materials may be formulated into the antimicrobial compositions. These may include: antimicrobials such as 2-hydroxy-4,2',4'-trichlorodiphenylether (triclosan), 2,6-dimethyl-4-hydroxychlorobenzene, and 3,4,4'-trichlorocarbanilide; scrub and exfoliating particles such as polyethylene and silica or alumina; cooling agents such as menthol; skin calming agents such as aloe vera; and colorants.

In addition, the antimicrobial compositions may further include 0 to 10% by weight of opacifiers and pearlizers such as ethylene glycol distearate, titanium dioxide or Lytron® 621 (Styrene/Acrylate copolymer); all of which are useful in enhancing the appearance or properties of the product.

Diluents other than water can include liquid or solid emollients, solvents, humectants, thickeners and powders. Examples of each of these types of vehicle, which can be used singly or as mixtures of one or more vehicles, are as follows: Emollients, such as stearyl alcohol, glyceryl monoricinoleate, mink oil, cetyl alcohol, isopropyl isostearate, stearic acid, isobutyl palmitate, isocetyl stearate, oleyl alcohol, isopropyl laurate, hexyl laurate, decyl oleate, octadecan-2-ol, isocetyl alcohol, eicosanyl alcohol, behenyl alcohol, cetyl palmitate, silicone oils such as dimethylpolysiloxane, di-n-butyl sebacate, isopropyl myristate, isopropyl palmitate, isopropyl stearate, butyl stearate, polyethylene glycol, triethylene glycol, lanolin, cocoa butter, corn oil, cotton seed oil, olive oil, palm kernel oil, rape seed oil, safflower seed oil, evening primrose oil, soybean oil, sunflower seed oil, avocado oil, sesame seed oil, coconut oil, arachis oil, castor oil, acetylated lanolin alcohols, petroleum jelly, mineral oil, butyl myristate, isostearic acid, palmitic acid, isopropyl linoleate, lauryl lactate, myristyl lactate, decyl oleate, myristyl myristate;; Solvents, such as ethyl alcohol, isopropanol, acetone, ethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether;

Advantageously, active agents other than skin conditioning agents defined above may be added to the antimicrobial composition. These active ingredients may be advantageously selected from bactericides, vitamins, anti-acne actives; anti-wrinkle, anti-skin atrophy and skin repair actives; skin barrier repair actives; non-steroidal cosmetic soothing actives; artificial tanning agents and accelerators; skin lightening actives; sunscreen actives; sebum stimulators; sebum inhibitors; anti-oxidants; protease inhibitors; skin tightening agents; anti-itch ingredients; hair growth inhibitors; 5-alpha reductase inhibitors; desquamating enzyme enhancers; anti- glycation agents; or mixtures thereof; and the like.

These active agents may be selected from water-soluble active agents, oil soluble active agents, pharmaceutically acceptable salts and mixtures thereof. The term "active agent" as used herein, means personal care actives which can be used to deliver a benefit to the skin and/or hair and which generally are not used to confer a skin conditioning benefit, such are delivered by emollients as defined above. The term "safe and effective amount" as used herein, means an amount of active agent high enough to modify the condition to be treated or to deliver the desired skin care benefit, but low enough to avoid serious side effects. The term "benefit," as used herein, means the therapeutic, prophylactic, and/or chronic benefits associated with treating a particular condition with one or more of the active agents described herein. What is a safe and effective amount of the active agent(s) will vary with the specific active agent, the ability of the active to penetrate through the skin, the age, health condition, and skin condition of the user, and other like factors.

The antimicrobial compositions of the present invention can comprise a wide range of other optional components. The CTFA Personal care Ingredient Handbook, Second Edition, 1992, which is incorporated by reference herein in its entirety, describes a wide variety of non-limiting personal care and pharmaceutical ingredients commonly used in the skin care industry, which are suitable for use in the antimicrobial compositions of the present invention. Examples include: antioxidants, binders, biological additives, buffering agents, colorants, thickeners, polymers, astringents, fragrance, humectants, opacifying agents, conditioners, pH adjusters, natural extracts, essential oils, skin sensates, skin soothing agents, and skin healing agents.

Now the invention will be demonstrated by the following non-limiting example. Examples:

Example 1

The antimicrobial compositions of the present invention are prepared according to Table 1 . For a 100 g batch, 4.2 ml BKC and 4.48 ml of DDAC was mixed in 30ml water and to this mixture, a solution of 0.05 g of Bromothymol blue in 20 ml water was added. The remaining amount was made up with water. The antimicrobial Compositions P1 and P2 are the preferred antimicrobial compositions of the present invention. Whereas, C1 and C2 are the control antimicrobial compositions which fall outside the scope of the present invention.

Table 1 : The Antimicrobial Compositions and their efficacy:

Example 2

Testing of antimicrobial efficacy:

The test was done according to BS EN 1276: Proof of bactericidal efficacy. BS EN 1276 is the European standard for the bactericidal activity of chemical disinfectants. In order to pass this standard, products must prove a bacteria kill rate of 99.999% within 5 minutes.

To a sterile container 10 ml of interfering agent (Bovine Serum- BSA) was added as a water contaminant. 10 ml of test bacterial suspension (1 .5-5 x 10⁸ cfu /ml ) was then added. This was mixed in a tube and placed in a water bath controlled at test temperature of about 30°C for about 2 minutes and then 179.9 ml of water was added and mixed. To the above 0.1 ml of test formulation was added and mixed continuously. At the end of the contact time of 5 minutes, 1 ml was aliquoted and transferred into a tube containing 8.0 ml neutralizer and 1.0 ml water for quenching the antimicrobial actives from further killing the microorganisms beyond the contact time of 5 minutes to obtain the neutralized test mixture. The neutralized test mixture was mixed and placed in a water bath controlled at 30°C. After neutralization the neutralized test mixture of 1 .0 ml was taken in duplicate and inoculated using the pour plate.

The Antimicrobial efficacy as provided in Table 1 shows that the first and second quaternary ammonium compounds act synergistically to provide > 5 log kill in 5 minutes which provides excellent disinfectant property to the water treated with the antimicrobial composition of the present invention as compared to the Control antimicrobial compositions C1 and C2. The compositions P1 and P2 also give a visual cue to the consumer when the colour changes from yellow to blue on dilution (1 :2000) that the compositions will be effective in synergistically killing the microorganisms thereby delivering the desired hygiene.

Claims

Claims:

1 ) An antimicrobial composition comprising: a. 0.01 to 15 wt% of a first quaternary ammonium composition comprising didecyl dimethyl ammonium chloride or a derivative thereof; and

wherein the antimicrobial composition further comprises a pH indicator.

2) An antimicrobial composition as claimed in claim 1 , wherein the antimicrobial composition further comprises at least 70 wt% of water.

3) An antimicrobial composition as claimed in claim 1 or 2, wherein the antimicrobial composition has pH value in the range of 2 to 7.

4) An antimicrobial composition according to any one of claims 1 to 3, wherein the ratio of first quaternary ammonium composition to the second quaternary ammonium composition is in the range of 10:1 to 1 :10.

5) Use of an antimicrobial composition as claimed in any one of the preceding claims 1 to 4 as a personal wash disinfectant liquid.

6) Use of an antimicrobial composition as claimed in any one of the preceding claims 1 to 4, for preparing a disinfecting aqueous solution by diluting the antimicrobial composition to at most to 5000 times with water.

7) Use of 0.01 to 15 wt% of a first quaternary ammonium composition comprising didecyl dimethyl ammonium chloride or a derivative thereof; and 0.01 to 15 wt% of a second quaternary ammonium composition comprising benzalkonium chloride (BKC) or a derivative thereof; and a pH indicator as a disinfectant for use in personal hygiene.

8) A method of personal wash, the method comprising steps of: a. diluting the antimicrobial composition according to anyone of the claims 1 to 4 to at most to 5000 times to obtain a diluted antimicrobial composition, and b. washing the surface of skin with the antimicrobial diluted composition resulting from step a.

9) A disinfectant kit for personal wash, the kit comprising: a. an antimicrobial composition according to anyone of the claims 1 to 4, b. a dispensing container, and

c. a set of instructions.

10) A kit as claimed in claim 9, wherein, the dispensing container comprises a dispensing tip capable of dispensing the antimicrobial composition in form of drops.

1 1 ) A kit as claimed in claim 9 or 10, wherein the dispensing container contains the antimicrobial composition according to claims 1 to 4.

12) A dispensing container containing the antimicrobial composition of anyone of the claims 1 to 4.

13) A method of manufacture of the antimicrobial composition according to anyone of the claims 1 to 4, the method comprising: a. adding the first quaternary ammonium composition and the second quaternary ammonium composition; and

b. adding pH indicator to obtain the antimicrobial composition.