FORM - 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2006
PROVISIONAL SPECIFICATION
(See Section 10 and Rule 13)


AN ANTIMICROBIAL COMPOSITION
HINDUSTAN UNILEVER LIMITED, a company incorporated under
the Indian Companies Act, 1913 and having its registered office
at 165/166, Backbay Reclamation, Mumbai -400 020, Maharashtra, India

The following specification describes the invention


Technical Field
The present invention relates to an antimicrobial composition. It particularly relates to an antimicrobial composition for cleansing or personal care.
Background and Prior Art
Sanitizing and disinfecting soap compositions comprising chlorine-based antimicrobial agent such as triclosan are known. Such compositions require rather long contact time to provide efficacious antimicrobial action. In practice, users, in particular children, do not spend long time in cleansing and as a result, cleaning with such compositions does not provide adequate prevention from surface or topical infection or adequate protection against diseases. The user, in spite of cleaning hands, is likely to have skin with relatively inadequate bacterial removal and may cause contamination of further animate and/or inanimate surfaces and lead to spreading of pathogens and consequent diseases. Users in general and children in particular who wash contaminated hands before meals with slow-acting antimicrobial compositions for relatively short time are at risk of contacting diseases.
Therefore, there is a need of providing a composition that provides relatively more efficacious antimicrobial action when cleaning period is relatively small, typically about 30 seconds or less.
Present inventors have surprisingly found that compositions comprising selected ingredients, namely thymol and terpineol, in selective proportions provide relatively quick antimicrobial action.

GB366870 (Namlooz Vennootschap,1931) describes a process of perfuming toilet soaps. Two different examples of soap perfumes, one comprising thymol and the other comprising terpineol are described. There is no disclosure of a specific soap composition comprising mixture of thymol and terpineol.
US6534042 (Pfizer, 2003) describes an oral care composition comprising from 0.01 to 5% by weight of citrus flavour or citrus flavour ingredient and from 0.01 to 5% by weight a phenolic selected from the group consisting of menthol eucalyptol, methyl salicylate, thymol, triclosan and mixtures thereof, and an orally acceptable carrier. The citrus flavour ingredient is selected from group consisting of limonene, citral, cadiene, decylaldehyde, linalool, terpineol, linalyl esters, terpinyl acetate, citronellol, alpha-terpinene, 2-dodecanal, alpha-pinene, beta-pinene, 3-penternal, decanal, and C8 to C10 and C12 aldehydes, acids, and esters found in citrus flavours and mixtures thereof. The oral care composition is said to be useful in retarding development of plaque, treating gingivitis and reducing viable population of microorganisms in oral cavity. There is no disclosure of a specific composition comprising thymol and terpineol.
GB508407 (Shepherd, 1938) describes an antiseptic product and method of preparation thereof comprising the steps of mixing salol and thymol in weight ratio of 1:3, melting the mixture and cooling to form crystals. An example of composition comprising 59 parts of the crystals, 41 parts of terpineol, 200 parts of red turkey oil and 200 parts of water is described. The composition described in this document comprises about 8% by weight thymol and about 8% by weight terpineol and is said to be particularly useful for disinfection of air.

None of the patents cited above address the problem of slow-acting antimicrobial composition
US5965518 (Nakatsu et al, 1999) describes a fragrance composition having antimicrobial activity comprising between 3 to 20% by weight of a phenolic compound and between 20 and 80% by weight of a non-aromatic terpenoid. Examples of phenolic compounds include amy! salicylate, cavacrol, dihydroeugenol, eugenol, hexyl eugenol, hexyl salicylate, isoeugenol, methyl eugenol, methyl isoeugenol, methyl salicylate, tert butyl cresol, thymol, and vanillin. Examples of non-aromatic terpenoid compounds include cedrene, cineole, citral, citronellal, citronellol, cymene, paradihydrolinalool, dihydromyrcenol, famesol, geraniol, hexyl cinnamaldehyde, hydroxycitronallol, hydroxycitronellal, isocitral, limonene, linalool, longifolene, menthol, nerol, nerolidiol, phellendrene, terpinene, terpinenol, and tetrahydromyrcenol. There is no disclosure of a specific composition comprising thymol and terpineol. The compositions reduce microbial number by at least 1.5 log cfu/mL within 5 minutes when used at about 0.25% concentration. Although there is some improvement in speed of antimicrobial action, there is still an on-going need for developing compositions with relatively fast antimicrobial action.
It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.
Another object of the present invention is to provide antimicrobial compositions that have relatively fast antimicrobial action.

Summary of the Invention
According to the present invention there is provided an antimicrobial composition comprising:
a. 0.05 to 5% by weight thymol,
b. 0.05 to 5% by weight terpineol, and
c. a carrier.
Detailed Description of the Invention
The antimicrobial composition comprises thymol, terpineol and a carrier. Various components of the antimicrobial composition are described below.
Thymol
The antimicrobial composition comprises preferably 0.05 to 5%, more preferably 0.1 to 1%, and most preferably 0.1 to 0.4% by weight thymol. Thymol may be added to the antimicrobial composition in purified form. Alternatively, thyme oil or thyme extract comprising thymol may be added to the antimicrobial composition. Thyme oil or thyme extract is obtained from the thyme plant. Thyme plant refers to a plant belonging be genus Thymus and includes but is not limited to the following species: Thymus vulgaris, Thymus zygis, Thymus satureoides, Thymus mastichina, Thymus broussonetti, Thymus maroccanus, Thymus pallidus, Thymus algeriensis, Thymus serpyllum, Thymus pulegoide, and Thymus citriodorus.
Terpineol
The antimicrobial composition comprises preferably 0.05 to 5%, more preferably 0.1 to 1%, and most preferably 0.4 to 0.6% by weight terpineol. The terpineol is preferably selected from alpha-terpineol, beta-terpineol, gamma-terpineol or mixtures thereof. It is particularly preferred that the

terpineol is alpha-terpineol. Terpineol may be added to the antimicrobial composition in purified form. Alternatively pine oil comprising terpineol may be added to the antimicrobial composition.
Carrier
The antimicrobial composition comprises a carrier. The carrier is selected from the group consisting of water, oil, solvent, inorganic particulate material, starch and mixtures thereof. The carrier is preferably from 0.1 to 99% by weight of the composition. The antimicrobial composition may be in form of a solid, liquid, gel, pastel or soft solid and the carrier may be selected by a person skilled in the art depending on the format of the antimicrobial composition.
The examples of inorganic particulate materials include clay, talc, calcite, dolomite, silica, and aluminosilicate. The examples of oils include mineral oils, vegetable oils, and petroleum-derived oils and waxes. The examples of solvents include alcohols, ethers and acetone.
The starch may be natural starch obtained from food grains or may be a modified starch.
Surfactant
The antimicrobial composition preferably comprises 1 to 80% surfactant. Any type of surfactant, i.e. anionic, cationic, nonionic, zwitterionic or amphoteric can be used although it is preferred that the surfactant is an anionic surfactant. A particularly preferred surfactant is a soap. The soap is preferably C8-C24 soap, more preferably C10-C20 soap and most preferably C12-C16 soap. The soap may or may not have one or more

carbon-carbon double bond or triple bond. The cation of the soap can be alkali metal, alkaline earth metal or ammonium. Preferably, the cation of the soap is selected from sodium, potassium or ammonium. More preferably the cation of the soap is sodium.
Additional ingredients
The composition may further comprise various additional ingredients known to a person skilled in the art. Such additional ingredients include but are not limited to: perfume, pigments, preservative, emollients, sunscreens, emulsifier, gelling agents, and thickening agents.
Format
The antimicrobial composition may be in form of a solid, a liquid, a gel or a paste. A person skilled in the art can prepare compositions in various formats by choosing one or more carrier materials and/or surfactant. The antimicrobial compositions of the present invention are useful for cleansing and care, in particular for skin cleansing and skin care. It is envisaged that the bacterial composition can be used as a leave-on product or a wash-off product. The antimicrobial composition of the present invention can also be used for cleansing and care of hard surfaces such as glass, metal, plastic and the like.
According to one aspect water is a preferred carrier. When water is the carrier, a preferred liquid bacterial composition comprises:
a. 0.05 to 5% by weight thymol,
b. 0.05 to 5% by weight terpineol
c. 10 to 99.9% by weight water, and;
d. 1 to 30% by weight surfactant.

The liquid antimicrobial composition is useful for skin cleansing, in particular for hand wash or a face wash.
When water is the carrier, a preferred solid bacterial composition comprises:
a. 0.05 to 5% by weight thymol,
b. 0.05 to 5% by weight terpineol,
c. 5 to 30% by weight water, and;
d. 30 to 90% by weight surfactant.
Preferably the surfactant is soap. The solid antimicrobial composition is preferably in form of a shaped solid, more preferably a bar. The solid antimicrobial composition is particularly useful for skin cleansing in particular for hand wash or a face wash.
According to another aspect, inorganic particulate material is a preferred carrier. When inorganic particulate material is the carrier, the antimicrobial composition is in a solid form. Preferably the inorganic particulate material is talc. When the inorganic particulate material is talc, the solid antimicrobial composition is particularly useful as a talcum powder for application on face or body.
According to a further aspect, solvent is a preferred carrier. Although any solvent can be used, alcohol is a preferred solvent. Short chain alcohols, in particular ethanol and propanol are particularly preferred as carrier for an antimicrobial wipe or an antimicrobial hand sanitizer composition.

Examples
The invention will now be demonstrated with examples. The examples are for purpose of illustration only and do not limit the scope of claims in any manner.
Compositions comprising various actives were prepared with water as a carrier (details given in Table 1 below). Eucalyptol and linalool were obtained from Fluka. Terpineot and thymol were obtained from Nishant aromas, India. Menthol, citral, citronellol, and geraniol were obtained from Som Santi Corporation, India. The composition of Example 1 is within the scope of the present invention whilst the compositions of Comparative Examples A-H are outside the scope of the present invention.
106 bacterial cells (E. coli ATCC 10536) were taken in a test tube and contacted with various compositions for a period of 15 seconds. Bacteria were taken out after 15 seconds of contact and presence of viable cells was determined by serial dilution and plating on agar plates. The absence of bacterial cells after contacting with the antimicrobial composition indicates highly efficacious antimicrobial composition corresponding to a log reduction of 6 in 15 seconds whilst presence of viable cells after contacting with the antimicrobial composition indicates relatively less efficacious and slow antimicrobial action.

Table 1: Antimicrobial efficacy

Ex
No Composition Viable E. coli after 15 seconds
1 Thymol (0.2%) + Terpineol (0.5%) Absent
A Thymol (0.2%) + Linalool (0.5%) Present
B Thymol (0.2%) + Citral (0.5%) Present
C Thymol (0.2%) + Geraniol (0.5%) Present
D Menthol (0.2%) + Terpineol (0.5%) Present
E Eucalyptol (0.2%) + Terpineol (0.5%) Present
F Triclosan (0.2%) + Terpineol (0.5%) Present
G Thymol {0.2%} Present )
H Terpineol (0.5%) Present
From the results, it is clear that specific mixture 0f terpineol with thymol of the present invention provides fast antimicrobial action with relatively high bactericidal efficacy against E. coli as compared to prior art mixtures of thymol with citrus flavour ingredients (US6534042, Pfizer, 2003) or terpineol with phenolic compounds (US5965518, Nakatsu et al, 1999). The results further demonstrate that the mixture of terpineol with thymol provides synergistically fast antimicrobial action with relatively high bactericidal efficacy against E. coli as compared to terpineol a|0ne or thymol alone.

It will be appreciated that the selection of thymol and terpineol in specific amounts provides a bactericidal action that is efficacious and yet relatively
fast.