WO2017063848A1

WO2017063848A1 - Sanitising and disinfecting compositions

Info

Publication number: WO2017063848A1
Application number: PCT/EP2016/072656
Authority: WO
Inventors: Shanthi APPAVOO; Srilaxmi Venkata Medepalli; Kalpana Kamalakar Nayak; Jayashree Anantharam Vadhyar
Original assignee: Unilever N.V.; Unilever Plc; Conopco, Inc., D/B/A Unilever
Priority date: 2015-10-12
Filing date: 2016-09-23
Publication date: 2017-04-20
Also published as: AR106316A1

Abstract

Disclosed is a composition comprising: (i) 5 to 47.5 wt% cationic surfactant; (ii) 5 to 47.5 wt% hydrotrope; and (iii) 0.5 to 20 wt% antimicrobial agent; wherein said antimicrobial agent is in the form of an oligodynamic metal or a compound of said metal; and wherein the amount of non-aqueous solvent in said composition is not greater than 2 wt%. The composition is capable of providing at least 2-log reduction in pathogenic bacterial count of a surface, when contacted with the surface in the form of an aqueous solution at dilution factor of one part by weight of composition to at least one thousand parts by weight of water.

Description

SANITISING AND DISINFECTING COMPOSITIONS Field of the invention The present invention relates to sanitizing and disinfecting compositions, particularly to compositions that are efficacious at very small amounts and in diluted form.

Background of the invention Sanitizing and disinfecting compositions are immensely useful since proper use reduces our contact and exposure to germs, microbes and pathogens. Therefore, such compositions play an important role in reducing the occurrence and spread of infectious diseases. Such compositions are useful for sanitizing several animate as well as inanimate surfaces; non-limiting examples thereof include hands, human body, bodies of pets and domestic animals, hard-surfaces such as kitchen sinks, toilets and dishes.

Most sanitizing and disinfecting compositions need a sufficiently long contact time with the animate or inanimate surface intended to be cleaned. The most common hygiene agents include strong acids and alkalies, phenolic compounds and oxidizing agents like peracids and hypohalites. In general, for efficacious cleaning, these ingredients are required at relatively high levels in the formulations. Most of the sanitizing and disinfecting compositions are formulated such they could be diluted with water by the user. Generally, the dilution factor is about 1 :100 to 1 :1000 parts by volume, where the 100/1000 indicate the parts by volume of water. At such dilution levels, the products generally provide up to 3-log reduction in the viable pathogenic bacterial count e.g. of E.coli.

US5916581 B1 (West Agro Inc, 1999) discloses stable iodine-based anti-microbial aqueous compositions in the form of dilutable concentrates or final use solutions which contains an available iodine-based ingredient and non- ionic surfactant supplemented with a quantity of an iodine solubilizing halide ion selected from the group consisting of chloride and bromide ions and mixtures thereof. US2002/0032241 A1 (Ciba Specialty Chemicals) discloses surface-active preparation containing 0.01 to 2% by weight of an antimicrobial (diphenyl ethers), 0.1 to 30% by weight of a hydrotrope, 6 to 50% by weight of one or more synthetic detergents or soaps, optionally a monohydric or dihydric alcohol and the balance being water. The

compositions are said to be effective against Gram-positive and Gram-negative bacteria as well as yeast and dermatophytes.

US2008/0267904 A1 (Taylor et.al.) discloses fast-acting antimicrobial compositions which contain a phenolic antimicrobial agent, a surfactant, a hydrotrope, a hydric solvent, and an organic acid. The antibacterial efficacy is stated to relate to the presence of a polyhydric solvent, a hydrotrope, and a surfactant. The phenolic antimicrobial agent is present in a continuous aqueous phase in an amount of at least 25% of saturation concentration and pH of the composition is 5 or less than that. WO 02/097020 A2 (Cussons International Limited) discloses a bactericidal liquid detergent composition which has 1 to 50 wt% surfactant, 0.1 to 5 wt% nonionic and non- phenolic antimicrobial agent, upto 10 wt% sulphonate hydrotrope and water soluble solvent having hydroxyl groups. The last two components add up to 0.5 to 30 wt% of the composition. The composition provides synergistic increase in bactericidal activity as determined by the European Suspension Test PrEN1040.

The compositions are efficacious at dilution factor greater than 1 :500, more particularly at least 1 :1000, and provide at least 2-log reduction in microbial count against at least some of the common pathogenic bacteria like E.coli.

Summary of the invention

Surprisingly, we have observed that synergistic interaction between a surfactant, a hydrotrope and an antimicrobial agent, wherein said antimicrobial agent is in the form of an oligodynamic metal or a compound of said metal, allows for formulating a highly efficacious antimicrobial composition which contains less than 2 wt% of non-aqueous solvents and which provides at least 2-log reduction in the viable microbial count of at least some of the common pathogenic bacteria like E.coli and in some cases at least 4-log reduction and even more. The compositions are found to be efficacious at significantly high dilution factors up to and including 1 :10000 times dilution with water.

In accordance with a first aspect is disclosed a composition comprising:

(i) 5 to 47.5 wt% cationic surfactant;

(ii) 5 to 47.5 wt% hydrotrope; and

(iii) 0.5 to 20 wt% antimicrobial agent;

wherein said antimicrobial agent is in the form of an oligodynamic metal or a compound of said metal; and

wherein the amount of non-aqueous solvent in said composition is not greater than 2 wt%.

The invention and all other aspects thereof will now be described in details. Detailed description of the invention

Throughout this description, the term sanitizing and other grammatical variations thereof refers to reduction of the number of viable microorganisms, especially pathogenic bacteria, in a given medium or on a given animate or inanimate surface. Typically, disinfection involves the destruction or inactivation of said microorganisms.

The term "microbes or microorganism" includes, for example, fungi (such as yeast and mould), bacteria, protozoans and algae. The term "wt%" refers to the weight of an ingredient based on total weight of the composition unless specified otherwise.

The compositions contain less than 2 wt% of a non-aqueous solvent, preferably less than 1 wt% non-aqueous solvent. Non-limiting examples of non-aqueous solvents include alcohols and humectants like glycerine and sorbitol as well as organic solvents like benzene, toluene, xylene, ethers, petroleum ether, hexane and other hydrocarbons.

It is preferred that compositions in accordance with the invention comprise: (i) 20 to 45 wt% cationic surfactant;

(ii) 20 to 45 wt% hydrotrope; and

(iii) 2 to 10 wt% antimicrobial agent

It is believed that the surfactant, the hydrotrope and the antimicrobial agent interact synergistically with each other thereby allowing to formulate a highly efficacious solvent- free antimicrobial composition which can provide at least 2-log reduction in the viable microbial count of at least some of the common pathogenic bacteria like E.coli and in some cases even more log-reduction. The compositions in accordance with this invention are efficacious at significantly high dilution factors of 1 part by weight of the composition to at least 1000 parts by weight of water, up to and including 1 :10000 times dilution with water.

The surfactant

Surfactants are used in cleansing compositions like soap bars and detergent powders for the basic purpose of cleaning.

Compositions in accordance with this invention comprise 5 to 47.5 wt% cationic surfactant.

The surfactant may be chosen from those described in well-known textbooks. These include "Surface Active Agents" Vol.1 , by Schwartz & Perry, Interscience 1949, Vol. 2 by Schwartz, Perry & Berch, Interscience 1958; and/or the current edition of

"McCutcheon's Emulsifiers and Detergents" published by Manufacturing Confectioners Company or "Tenside-Taschenbuch", H. Stache, 2nd Edn., Carl Hauser Verlag, 1981 ; "Handbook of Industrial Surfactants" (4th Edn.) by Michael Ash and Irene Ash;

Synapse Information Resources, 2008. It is preferred that the cationic surfactant is a quaternary ammonium compound. The quaternary ammonium compounds have general formula Ri R2Rs 4N⁺X^", wherein Ri is a C12-C18 alkyl group, an aryl group or an aryl- alkyl group, R2 is selected from an aryl group or an aryl-alkyl group having 1 to 5 carbon atoms or a C1-C3 alkyl group, R3 and R₄ are independently selected from C1-C3 alkyl groups and X^" is an inorganic anion. It is preferred that the inorganic anion is chosen from halides (including chloride, bromide and iodide), phosphate, sulphite, sulphate, bisulphate or hydroxyl ions. More preferably the anion is a halide ion or sulphate, most preferably a chloride or sulphate. Cetyl trimethylammonium halides and benzalkonium chlorides are specifically preferred as examples of suitable compounds. It is further preferred that the cationic surfactant is benzalkonium chloride.

Hydrotrope In addition to the surfactant, the compositions according to the present invention comprise a hydrotrope. The compositions comprise 5 to 47.5 wt% hydrotrope. A hydrotrope is an ingredient that generally enhances water solubility of other compounds, especially surfactants. The hydrotrope in accordance with this invention is devoid of surface activity.

Hydrotropes may be cationic or anionic depending on the ionic charges thereon.

In accordance with one aspect of the invention, the hydrotrope is anionic. A particularly preferred anionic hydrotrope is sodium benzoate.

Other preferred anionic hydrotropes include sodium cumene sulfonate, ammonium cumene sulfonate, ammonium xylene sulfonate, potassium toluene sulfonate, sodium toluene sulfonate, sodium xylene sulfonate, toluene sulfonic acid, xylene sulfonic acid, sodium polynaphthalene sulfonate, sodium polystyrene sulfonate, sodium

methylnaphthalene sulfonate, sodium camphor sulfonate, and disodium succinate and sodium benzoate. Alternatively, the hydrotrope in compositions according to the invention is cationic. It is preferred that the cationic hydrotrope is tallow, aniline hydrochloride, o-toluidine hydrochloride or p-toluidine hydrochloride. Tallow is particularly preferred. Antimicrobial agent

The compositions in accordance with the invention comprise 0.5 to 5 wt% of at least one antimicrobial agent. The agent is primarily responsible for antibacterial action but its efficacy increases due to the presence of the surfactant and the hydrotrope as the three ingredients act synergistically to cumulatively provide reduction in the count of viable pathogenic bacteria, which is greater than the arithmetic sum of reduction provided by them individually.

The antimicrobial agent is in the form of an oligodynamic metal or a compound of the metal. When the antimicrobial agent is a compound of an oligodynamic agent, such as silver nitrate; it is the actual metal content in the compound which is responsible for antimicrobial action. For example, if a composition contains 20 wt% silver nitrate, then the silver content is 12.7 parts by weight and this figure can be easily calculated with the relative molecular mass (molecular weight) of the compound and the relative atomic mass (atomic weight) of the oligodynamic metal.

It is further preferred that the oligodynamic metal is silver, copper or zinc. Silver is particularly preferred. When the metal is silver, it is preferred that the compound of the oligidynamic metal is silver nitrate, silver acetate, silver pentetate, silver oxide, silver sulfate, silver benzoate, silver salicylate, silver carbonate, silver citrate or silver phosphate It is particularly preferred that the compound of the metal is silver nitrate, silver acetate or silver pentetate. Metallic antimicrobial agents, may for example, be in the form of silver or copper particles, especially nanoparticles. Other suitable optionally additional antibacterial agents include 2-hydroxy-4,2',4'- trichlorodiphenylether (DP300); 2,6-dimethyl-4-hydroxychlorobenzene (PCMX); 3,4,4'- trichlorocarbanilide (TCC); 3-trifluoromethyl-4,4'-dichlorocarbaniide (TFC); 2,2'- dihydroxy- 3,3',5,5',6,6'-hexachlorophenylmethane; 2,2'-dihydroxy-3,3', 5,5'- tetrachlorodiphenylmethane; 2,2'-dihydroxy-3,3',dibromo-5,5'- dichlorodiphenylmethane; 2-hydroxy-4,4'-dichlorodiphenylether; 2-hydroxy- 3,5',4-tribromodiphenlylether; and 1 - hydroxyl-4-methyl-6-(2,4,4-trimethylpentyl)- 2(1 H)-pyridinone (Octopirox). Alternatively the optionallly additionalantibactenal agent is thymol or terpeniol or eugenol, optimally used in any combinations of two or three. The compositions may then have strong smell, which may if needed, be masked by use of perfumes. As an alternative to thymol, thyme oil or thyme extract may also be added. Thyme oil or thyme extract is obtained from the thyme plant, belonging be genus Thymus and includes but is not limited to Thymus vulgaris, Thymus zygis, Thymus satureoides, Thymus mastichina, Thymus broussonetti, Thymus maroccanus, Thymus pallidus, Thymus algeriensis, Thymus serpyllum, Thymus pulegoide, and Thymus citriodorus.

Other ingredients:

An antibacterial composition falling within the scope of the present invention can be formulated by using the three ingredients as disclosed earlier such that the total amounts add up to 100 wt%. However, some additional ingredients may be included in the compositions according to the invention in order to make the compositions more flowable, handy and easy to dose.

In addition, the compositions may also include colour, perfume, stabilisers and other ingredients which are usually present in home and personal care compositions. The compositions in accordance with the invention comprise not more than 2 wt% nonaqueous solvent, but the compositions may comprise water. In such cases, the water serves as a carrier or a medium. The carrier, may alternatively, be a non-aqueous ingredient. Such other ingredients include inert carriers like clay, cellulose, clay, talc, calcite, dolomite, silica and starch. The carrier may be selected by a person skilled in the art depending on the format of the antimicrobial composition. In certain other

embodiments, suitable carriers may include, for example, cyclodextrin, waxes, alkali and alkaline earth (e.g., sodium, magnesium, potassium) metal salts (e.g., chloride, nitrate, bromide, sulphate) and charcoal.

Builders are generally used in detergent compositions to aid detergency. Without wishing to be bound by theory, it is believed that such builders, if present, are likely to have an adverse impact on efficacy of the compositions in accordance with the invention.

Therefore it is preferred that total amount of detergency builder in the compositions in accordance with the invention is less than 1 wt%. The detergency builder is detergency builder is carbonate, sesquicarbonate, zeolite or aluminosilicate.

Form and packaging

The compositions may be liquid, solid or semi-solid depending upon the nature of the ingredients. They may be packed in any suitable form of packing such as plastic or glass containers, bottles, pouches and sachets. Such container would usually be equipped with a dosing mechanism and preferably a measured dosage. Sachets may be of the unit- dose type.

Use and method in accordance with the invention:

Compositions in accordance with this invention may be used to sanitise any animate or inanimate surface. Examples of such surfaces have been given earlier.

The compositions may be used as antiseptic composition. By that is meant a composition that may be used as such or after dilution with water for first aid treatment of cuts on skin and other keratinous substrates of the body. They may be used for sanitizing surfaces which are believed to be high in germ count e.g., nappies, hospital linen, undergarments, and hard surfaces like those in the kitchen, bathrooms and toilets, for example glass, metal, plastic or porcelain. It is preferred that the consumers are instructed to dilute the product with water by a dilution factor of more than 1 :1000, preferably 1 :5000 and more preferably 1 :10000, before actual use. Dilution may accompany a visual cue such as change in colour or change from transparent/translucent form to a turbid form. Suitable formulation techniques may be employed for such effects.

The composition (in diluted form) can be applied to the surface by any means such as spraying. The composition is preferably allowed to remain in contact therewith for at least one minute after which, wherever possible, the composition may be wiped off if desired or may be rinsed-off with water.

The composition may, non-limitingly, be a floor cleaner, a kitchen cleaner, a toilet cleaner, a hand sanitizer or a bath aid which can be dosed to a bucket of water which is used for bathing or alternatively dosed in to an overhead tank.

In accordance with another aspect is disclosed the use in a therapeutic method of the compositions of the present invention.

In accordance with another aspect is disclosed the use of compositions of the present invention to sanitise an animate or inanimate surface.

It is preferred that the composition is capable of providing at least 2-log reduction in pathogenic bacterial count of said surface, when contacted with said surface in the form of an aqueous solution at dilution factor of one part by weight of composition to at least one thousand parts by weight of water.

In accordance with a yet further aspect is disclosed use of a composition of the first aspect to sanitise an animate or inanimate surface in a non-therapeutic manner.

In accordance with a yet further aspect is disclosed a method of sanitising an animate or inanimate surface by contacting said surface with a composition of the first aspect. In accordance with a further aspect is disclosed a method of sanitising an animate or inanimate surface in a non-therapeutic manner by contacting said surface with a composition of the first aspect. The following non-limiting examples further illustrate the preferred embodiments of the invention. All percentages referred to in the examples and throughout this specification are by weight based on total weight unless otherwise indicated. Examples

Example 1 : Efficacy of a composition according to the invention

A composition in accordance with the invention was prepared by mixing pre-weighed amounts of a surfactant, an anionic hydrotrope and an antimicrobial agent. The final formulation is shown in table 1. This was an example where the surfactant (cationic) and the hydrotrope (negative) had dissimilar ionic charges.

Table 1

^*Note: The silver metal content was 12.7 parts by weight, but the composition contained 20 g silver nitrate. The calculation is as follows: 107.86X20/169.87 E. coli ATCC 10536, P. aeruginosa ATCC 15442 and S. aureus ATCC 6538 were subjected to certain tests to ascertain the efficacy of the composition of table 1. A modified form of the standard European Suspension Test BS EN 1276 was used which is briefly described below. One gram of the composition of table 1 was mixed with enough water to prepare a dilute solution. An aliquot of this dilute solution was added to a suspension of the concerned bacterium which was pre-mixed with an interfering substance. The interfering substance was 1 ml of bovine serum albumin (0.3% solution). The mix was gently agitated for five minutes at 20 °C, and was allowed contact with the bacterium for sixty minutes. At the end of the contact time, an aliquot was taken and the bactericidal activity therein was immediately neutralised or suppressed by known quenching method. The number of surviving bacteria were determined and reduction in their numbers was calculated acordingly. The tests were performed against E. coli, P. aeruginosa, S. aureus and £. coli as the pathogenic bacteria.

The observations are summarised in table 2.

Table 2

The data in table 1 indicates that none of the ingredients alone could not bring about the extent of log reduction that was possible with the composition of table 1 . The experiments were conducted at a dilution factor of 1 :6400, which indicates that the compositions were significantly diluted in water.

Example 2: Antimicrobial efficacy of another composition according to the invention

Another composition in accordance with the invention was prepared by mixing pre- weighted quantities of a surfactant, a hydrotrope and an antimicrobial agent. The final formulation is shown in table 3. This was an example where the surfactant (cationic) and the hydrotrope (cationic) had identical ionic charges and the composition also include water.

Table 3

Ingredient Wt%

Benzalkonium chloride 5.00

Silver nitrate^* 3.15 Tallow 5.00

Water Balance to 100

^*Note: The silver content was 2.22 parts by weight (107.86X3.5/169.87) The observations pertaining to this composition are summarised in table 4.

Table 4

The data in table 4 indicates that none of the ingredients alone could bring about even 2-log reduction in the viable bacterial count of the organisms. However the composition of table 3 brought about more than 2 log reduction in the viable bacterial count of all three organisms. The experiments were conducted at dilution factor of 1 :10000 which is extreme situation of dilution.

Claims

1. A composition comprising:

(i) 5 to 47.5 wt% cationic surfactant;

(ii) 5 to 47.5 wt% hydrotrope; and

(iii) 0.5 to 20 wt% antimicrobial agent;

2. A composition as claimed in claimed in claim 1 wherein said oligodynamic metal is silver, copper or zinc.

3. A composition as claimed in claim 2 wherein said oligodynamic metal is silver.

4. A composition as claimed in claim 2 or 3 wherein compound of said metal is silver nitrate, silver acetate or silver pentetate.

5. A composition as claimed in any one of claims 1 to 4 wherein said cationic

surfactant is a quaternary ammonium compound.

6. A composition as claimed in any one of claims 1 to 5 wherein said hydrotrope is cationic.

7. A composition as claimed in claim 6 wherein said hydrotrope is tallow or aniline hydrochloride, o-toluidene hydrochloride or p-toluidene hydrochloride.

8. A composition as claimed in any one of claims 1 to 5 wherein said hydrotrope is anionic.

9. A composition as claimed in claim 8 wherein said hydrotrope is sodium benzoate.

10. A composition as claimed in any one of claims 1 to 9 wherein total amount of detergency builder in said composition is less than 1 wt%.

11. A composition as claimed in claim 10 wherein said detergency builder is carbonate, sesquicarbonate, zeolite or aluminosilicate.

12. A composition according to any one of claims 1 to 1 1 for use in a therapeutic

method.

13. A composition according to any one of claims 1 to 1 1 for use to sanitise an animate or inanimate surface.

14. A composition for use as claimed in claim 13 wherein said composition is capable of providing at least 2-log reduction in pathogenic bacterial count of said surface, when contacted with said surface in the form of an aqueous solution at dilution factor of one part by weight of composition to at least one thousand parts by weight of water.