AN ANTIMICROBIAL COMPOSITION TO COMBAT BAD ODOR

Abstract

The present invention relates to an antimicrobial composition, more particularly to a method and composition for preventing or treating malodor, especially body odor. This is achieved through a composition comprising alkyl-substituted dihydroxybenzene in combination with thymol or terpineol. The composition is also noted to have anti-acne benefits.

Description

AN ANTIMICROBIAL COMPOSITION TO COMBAT BAD ODOR FIELD OF INVENTION The present invention relates to an antimicrobial composition, more particularly to a method and composition for preventing or treating malodor, especially in the human armpit. The composition is also noted to have anti-acne benefits. BACKGROUND OF THE INVENTION In humans, the skin of the forearms provides a unique niche for bacteria. Through the secretions of various glands that open onto the skin, the environment is rich in nutrients and hosts a unique microbial community. In humans, the link between axillary apocrine gland secretions, forearm bacteria, and body odor has long been established. Culture-based studies of this relationship found that the axillary microbiota is dominated by species of Staphylococcus, Corynebacterium, and Propionibacterium. More recent independent culture studies have confirmed the presence of these genera and, additionally, indicated the presence of Gram-positive anaerobic cocci (GPACs) belonging to the genera Anaerococcus and Peptoniphilus.The main reason for these studies was to identify the target bacterial species responsible for underarm odor and, therefore, to design strategies to control it and provide the benefit of reducing underarm odor. Human body odor contains various chemicals, but the most pungent and recognizable are thioalcohols. These molecules are created through a series of chemical reactions that begin with an odorless precursor: a compound produced in glands located in the armpits. Popular theory suggests that a type of bacteria called Staphylococcus hominis (S. hominis) takes these molecules and transforms them into thioalcohols, which then give body its characteristic odor. Body odor has been addressed in many ways. Some approaches include using perfumes to mask the smell, although this only provides temporary relief. Antiperspirants are also available, but they block the sweat glands, depriving the body of a mechanism for excreting unwanted chemicals through perspiration. The inventors of this product, seeking to solve the problem of body odor, worked on methods to control the bacterial population in the forearm area. It is possible to completely eradicate or minimize all bacteria on the skin using agents such as alcohol. However, the inventors of this product wish to use more natural agents that are less aggressive on the skin. The inventors of this product thus began working to provide "natural" solutions to the problem of bad odor. Ultimately, they discovered a combination of a specific alkyl-substituted dihydroxybenzene and compounds such as thymol and / or terpineol that interact synergistically to provide the desired benefit of odor reduction. WO 9517159 (P&G, 1995) describes a concentrated mouthwash for the effective delivery of antimicrobials comprising a combination of cationic antimicrobials, non-cationic antimicrobials, and a flavoring agent to provide anti-plaque benefits. Although this composition has been shown to provide antibacterial benefits with the non-cationic antibacterial selected from hexylresorcinol or thymol along with several other such agents, it does not disclose that this composition is effective against odor-causing bacteria on the forearms, such as S. hominis. Next, the inventors discovered that this composition is also effective in combating acne. Acne, also known as acne vulgaris, is a common skin condition that affects almost all adolescents and adults at some point in their lives. It has a complex etiology, involving abnormal keratinization, excessive sebum production, androgen function, bacterial growth, and immune hypersensitivity. Although one or more of the above processes are correlated with acne, the triggering factor and the exact sequence of events leading to the formation of acne lesions are not fully understood. Other factors that have been linked to acne include the presence of free radicals with the resulting oxidative stress that leads to cell damage. Acne has been observed to commonly appear in areas rich in sebaceous glands, such as the face, neck, and back. The bacterium Cutibacterium acnes (C. acnes), formerly Propionibacterium acnes, has also been implicated in the development of acne. It is one of the important and dominant bacteria residing on the surface of human facial skin. C. acnes is a Gram-positive, aerotolerant, anaerobic, slow-growing, rod-shaped bacterium. It resides in the sebaceous glands and constitutes an important part of the skin's commensal microbiota. C. acnes uses sebum and byproducts from the surrounding skin tissue as sources of energy and nutrients. This results in the release of certain fatty acids that can irritate the follicle wall and induce inflammation, leading to acne or acne vulgaris. Acne vulgaris is a chronic inflammatory disorder of the pilosebaceous gland. It affects almost all adolescents at some point in their lives, and between 15 and 20% experience moderate to severe forms of acne. Acne has been treated in many ways. Most treatments take several weeks to months before a noticeable change is seen. Benzoyl peroxide, which has an antibacterial effect, has been used for mild cases of comedones. In very severe cases of acne, antibiotics such as tetracycline, erythromycin, and clindamycin have been used. Antibiotics are thought to work through various mechanisms, the most important being the reduction of the number of bacteria in and around the follicle. They are also thought to reduce the irritating chemicals produced by white blood cells in sebum, thus reducing the inflammatory response. However, the drawback of antibiotics and other types of general antimicrobial treatments is that they are broad-spectrum and help to eliminate or inhibit most bacteria on the skin. Most treatments, as summarized above, involve the use of synthetic chemicals. Ultimately, more and more people prefer the use of materials that are “natural” or nature-identical. In this respect as well, the present invention involves a combination of, for example, a resorcinol derivative and an essential oil selected from thymol or terpineol, which provides a more natural method for addressing or alleviating the problem of acne. Therefore, it is an objective of the present invention to provide an antimicrobial composition to combat bad body odor. Another objective of the present invention is to provide solutions to combat bad body odor while ensuring the prevention or reduction of the occurrence of acne. BRIEF DESCRIPTION OF THE INVENTION The first aspect of the present invention relates to an antimicrobial composition comprising: (i) alkyl-substituted dihydroxybenzene wherein the alkyl group comprises from 2 to 10 carbon atoms; (i) a selected essential oil compound of thymol or terpineol; and, (iii) a cosmetically acceptable base. Another aspect of the present invention relates to a composition according to the first aspect for providing a reduction of bad odor on the skin when applying the composition of the first aspect to the desired skin surface. Yet another aspect of the present invention relates to a composition according to the first aspect for providing an anti-acne benefit to the skin after application of the composition of the first aspect to the desired skin surface. DETAILED DESCRIPTION OF THE INVENTION These and other aspects, features, and advantages will be evident to those of ordinary experience in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be used in any other aspect of the invention. The word “comprising” is intended to mean “including” but not necessarily “consisting of” or “composed of.” In other words, the steps or options listed need not be exhaustive. Note that the examples provided 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 and ratios contained herein are weight / weight percentages unless otherwise stated. Except in performance and comparative examples, or where explicitly stated otherwise, all numbers in this description indicating quantities of material or reaction conditions, physical properties of materials, and / or use shall be understood to be modified by the word “approximately.” Unless otherwise specified, numerical variations expressed in the format “xay” shall be understood to include x and y. When multiple preferred variations are described for a specific characteristic in the format “xay,” it shall be understood that all variations combining different endpoints are also included. The composition according to this invention may be in the form of a leave-in or wash-out format to provide selective odor control in topical areas, for example, the skin and / or hair of mammals, especially humans. Such a composition includes any product applied to the human body to also improve appearance, cleanliness, or overall aesthetics. The composition of the present invention may be supplied with a topically / cosmetically acceptable base, which may be an anhydrous base, a liquid, a lotion, a cream, a foam, a scrub, a gel, an emulsion, or a propellant. “Skin,” as used herein, includes the skin of any part of the body (for example, neck, chest, back, arms, forearms, hands, legs, buttocks, and scalp), especially the forearms.It is especially useful for reducing unpleasant odors on the forearm (or armpit) or any other part of the body where odor originates. To obtain the desired anti-acne benefit, the composition of the invention could be applied to any part of the body generally affected by acne. Such surfaces include the face or any other part of the body where acne forms. The antimicrobial composition of the invention comprises alkyl-substituted dihydroxybenzene wherein the alkyl group comprises from 2 to 10 carbon atoms; an essential oil compound selected from thymol or terpineol; and a cosmetically acceptable base. Alkyl-substituted dihydroxybenzene has the general chemical structure (I) as provided below: where Ri is an alkyl group from C1 to C10; and each of R2 to Re is either an OH or H group; and where at least two of R2 to Re are OH. R1 is an alkyl group from C2 to C10. The preferred alkyl-substituted dihydroxybenzene structure for use in the present invention is where R1 is an alkyl group from C1 to C10; R2 and Re are OH. R1 is an alkyl group from C2 to C10. Preferably, R1 is an alkyl group comprising 2 to 10 carbon atoms, preferably comprising 2 to 6 carbon atoms, and most preferably comprising 2, 4, or 6 carbon atoms. The two hydroxyl groups are generally at positions 1 and 3. Such compounds are often called substituted resorcinols. Therefore, the most preferred compounds are ethylresorcinol, butylresorcinol, or hexylresorcinol. 4-Substituted resorcinol is the most preferred. Therefore, the resorcinols that can be used are 4-ethylresorcinol, 4-butylresorcinol, or 4-hexylresorcinol. The most preferred compound for use in the present invention is 4-hexylresorcinol. This compound has the structure provided below: iviA / a / zuzz / uio 11 and The compound is also known by its synonyms 4-hexylbenzen-1,3-diol and 4-hexyl-1,3-benzendiol. Hexylresorcinol is known to have antiseptic and local anesthetic properties. It has been used topically for minor skin infections and in oral solutions for pain relief and as a first-aid antiseptic. It has also been used as a skin-brightening agent in skincare. The compound is also known to have antioxidant properties and has therefore been used in skincare formulations to promote a more even skin tone or in anti-aging products. The composition preferably comprises from 0.0005% to 10% by weight of alkyl-substituted dihydroxybenzene. More preferably, it is present in an amount ranging from 0.001% to 2% by weight of the composition. The composition of the invention preferably comprises thymol or terpineol. The structure of thymol is provided below: Thymol Alternatively, the composition may include terpineol. The terpineol is preferably selected from alpha-terpineol, beta-terpineol, gamma-terpineol, or mixtures thereof. In particular, alpha-terpineol is preferred. The structure of a terpineol compound is provided below: iviA / a / zuzz / uio 11 and OH Thymol and terpineol are both essential oil compounds. Both are known to have a strong odor and are therefore used in perfumery compositions. They are also known to have antimicrobial activity. They can be extracted from naturally occurring herbs or prepared synthetically and used in the present invention. In the present invention, both are used from synthetic sources. The essential oil compound is included at concentrations of 0.001% to 5%, preferably 0.005% to 1%, and more preferably 0.005% to 0.5% by weight of the composition. According to a particularly preferred aspect of the invention, the composition comprises a mixture of thymol and terpineol. Other essential oil compounds that may optionally be included in the composition of the invention are carvacrol, (E)-2-(prop-1-enyl)phenol, 2-propylphenol, 4-pentylphenol, 4-sec-butylphenol, 2-benzylphenol, eugenol, or combinations thereof. Without wishing to be limited by theory, the inventors of the present invention believe that the combination of the active ingredients claimed herein works for the following reason. The alkyl-substituted dihydroxybenzene, for example, hexylresorcinol, interacts with the biological membranes and intracellular proteins of bacteria. Due to its amphiphilic nature, it penetrates the bacterial cell to damage membrane integrity and increase permeability. Once inside the cell, it may act on multiple targets and eliminate the bacteria. The essential oil compound, for example, thymol, a monoterpenoid, is a fast-acting antimicrobial that destabilizes bacterial membranes. We observed a synergistic effect between the alkyl-substituted dihydroxybenzene (for example, hexylresorcinol) and the essential oil compound, for example, thymol, in our assays.Our hypothesis is that thymol's rapid action helps in the penetration of hexylresorcinol and, therefore, in combination, acts as a potent, fast-acting, synergistic antimicrobial combination. The composition of the invention comprises a cosmetically acceptable base. The cosmetically acceptable base preferably comprises a gel, emulsion, lotion, paste, spray, or cream. In the aforementioned forms, the cosmetically acceptable base preferably comprises water, surfactant, or combinations thereof. The surfactant is preferably an anionic surfactant, preferably soap. A particularly preferred form of the composition of the invention involves a cosmetically acceptable base that is anhydrous. Such anhydrous compositions are useful for deodorant products, especially for application to the forearm region. These compositions are generally supplied in stick form, or from a roll-on device, or supplied from an aerosol can or as a sprayer. The composition can also be supplied in the form of a disinfectant comprising more than 60% ethanol by weight of the composition. The composition comprises a topically / cosmetically acceptable base, preferably anhydrous. An anhydrous base is defined as having a water content of less than 5% by weight, preferably less than 2% by weight, and more preferably less than 1% by weight, and ideally absent from the composition. To enable this, the anhydrous base preferably comprises a silicone compound, an alcohol, or a wax. The alcohol, when used, could be a low-boiling-point (C2 to C4) alcohol or a polyhydric alcohol, preferably a polyhydric alcohol. The pH of the preferred composition is greater than 3.5, most preferably in the range of 4 to 7. The pH of the composition of the invention is measured using the following procedure: equal volumes of the composition and the model ionic sweat (pH 6.1) are mixed, and the pH value is measured using a pH test paper of precise variation. The anhydrous composition of the invention preferably comprises a polyhydric alcohol. A polyhydric alcohol is also referred to simply as a polyol. A polyhydric alcohol according to the present invention is a compound having two or more hydroxyl groups. Suitable classes of polyhydric alcohols that may be included in the composition of the invention are monomeric polyols, polyalkylene glycols, or sugars. Preferred monomeric polyols are glycol; alkylene glycol, for example, propylene glycol; glycerol; or xylitol, most preferably propylene glycol. Suitable polyalkylene glycols are polyethylene glycol or polypropylene glycol. The sugars for inclusion in the invention may be monomeric, dimeric, trimeric, or polymeric. Preferred sugars include glucose, fructose, mannose, sucrose, threitol, erythritol, sorbitol, mannitol, galactitol, adonitol, dextran, or cyclodextrin. Of these, the most preferred sugars are glucose, fructose, sucrose, sorbitol, mannitol, adonitol, dextran, or cyclodextrin. Other components commonly included in conventional compositions may also be incorporated into the composition of the present invention. Such components include skin care agents such as emollients, humectants, and skin barrier promoters; skin appearance modifiers such as skin brightening agents and skin softening agents; antimicrobial agents, in particular organic antimicrobial agents; and preservatives. The composition of the invention can be applied cosmetically and topically to the skin, generally speaking, by one of two methods. Some consumers prefer one method and others the other. In one method, sometimes called the contact method, a composition is rubbed onto the skin surface, depositing a fraction of the composition as it passes over it. In the second method, sometimes called the non-contact method, the composition is sprayed from a dispenser held close to the skin, often over an area of ​​approximately 10 to 20 cm². The spray can be developed by mechanical means to generate pressure on the contents of the dispenser, such as a pump or a compressible sidewall, or by internally generated pressure arising from a fraction of a liquefied propellant that volatilizes. The dispenser is commonly referred to as an aerosol. Generally speaking, there are two types of contact compositions. One is liquid and is typically applied using a roll-on dispenser or possibly absorbed onto a wipe. In the second, the antiperspirant active is distributed within a carrier fluid that forms a continuous, gelled phase. In one variation, the carrier fluid comprises a solvent for the antiperspirant, and in a second variation, the antiperspirant remains a particulate solid suspended in an oil, usually a mixture of oils. Soft or bar-shaped solid compositions Many different materials have been proposed as gelling agents for a continuous oil phase, including waxes, small-molecule gelling agents, and polymers. Each has its advantages, and one of the most popular classes of gelling agents comprises waxes, at least in part due to their easy availability and ease of processing, particularly linear fatty alcohol wax gelling agents. A gelled antiperspirant composition is applied topically to the skin by rubbing it in, thus depositing a thin film on the skin. The nature of the film depends largely on the gelling agent used. Although wax fatty alcohols have been used as gelling agents for many years and are effective at gelling, the resulting product is rather ineffective in improving the visual appearance of the skin, particularly the skin of the forearms, to which the composition has been applied. This problem has been solved by including improving materials, for example, di- or polyhydric humectants and / or a triglyceride oil. Roll-on Liquid antiperspirant compositions applied via roll-on can generally be divided into two classes: those in which an antiperspirant active ingredient is suspended in a hydrophobic carrier, such as a volatile silicone, and those in which the antiperspirant active ingredient is dissolved in a liquid carrier. The latter has proven more popular. There are primarily two types of solvent carrier liquids: those that are predominantly alcoholic, meaning the majority of the solvent carrier fluid comprises ethanol, and those in which the carrier fluid is primarily water. The former was very popular because ethanol is a mild bactericide in its own right, although its popularity declined because it stings, especially if the surface to which the composition was applied is damaged or cut, as can easily happen during shaving or other hair removal procedures. The second class of formulations, which is an alternative to alcoholic formulations, comprises a dispersion of water-insoluble or very slightly water-soluble ingredients in an aqueous solution of the antiperspirant. Hereinafter, such compositions will be referred to as emulsions. Roll-on antiperspirant emulsions commonly comprise one or more emulsifiers to maintain a distribution of the water-soluble ingredients. Aerosol compositions The composition of the invention can be supplied via an aerosol composition comprising a propellant in addition to the other ingredients described above. Typically, the propellant is used in a weight ratio with the base formulation of 95:5 to 5:95. Depending on the propellant, in such aerosol compositions, the propellant-to-base formulation ratio is normally at least 20:80, generally at least 30:70, particularly at least 40:60, and in many formulations, the weight ratio is 90:10 to 50:50. Occasionally, a ratio variation of 70:30 to 90:10 is preferred. iviA / a / zuzz / uio 11 and In general, the propellants herein are one of three classes; i) low boiling point gases liquefied by compression, ii) volatile ethers and iii) compressed non-oxidizing gases. Class i) is conveniently a low-boiling-point material, typically boiling below -5°C, and frequently below -15°C, and in particular, alkanes and / or halogenated hydrocarbons. This class of propellant normally liquefies at the pressure of the aerosol can and evaporates to generate the pressure to expel the composition from the can. Examples of particularly suitable alkanes include propane, butane, or isobutane. The second class of propellant comprises a highly volatile ether, of which the most commonly used ether to date is dimethyl ether. This propellant can be advantageously employed at a relatively low weight ratio of propellant to base formulation, for example, as low as 5:95. It can also be used in mixtures with, for example, compressible / liquefiable alkane gases. The third class of propellants comprises compressed non-oxidizing gases and, in particular, carbon dioxide or nitrogen.Inert gases such as neon are a theoretical alternative. When the composition of the invention is supplied in a roll-on, firm solid, or stick format, the topically acceptable base comprises a hydrophobic or aqueous carrier. The hydrophobic carrier in such cases may comprise a silicone compound, a low-boiling-point alcohol, or a wax. When the composition comprises a propellant, it is supplied in aerosol form. The composition of the preferred invention further comprises a fragrance. A fragrance is understood to be a molecule or a composition comprising a group of molecules that produces a pleasant odor. The preferred composition comprises a fragrance in 0.1 to 3% by weight of the composition. Skin care composition The composition of the present invention can be used for skin care. The cosmetically acceptable base in such cases can be a liquid or solid material. Typically, the cosmetically acceptable base is present in an amount ranging from 10 to 99.9%, most preferably from 20 to 95%, with the highest preference being from 40 to 85% of the total weight of the composition, including all variations therein. In particular, it is preferred that the cosmetically acceptable carrier include water. Water is preferred in an amount of 30 to 90%, with a higher preference of 30 to 85%, and a maximum preference of 30 to 80% by weight of the total sunscreen composition. In addition to water, suitable carrier classes include silicones, polyhydric alcohols, hydrocarbons, triglycerides, and thickening powders. Cosmetically acceptable bases, preferably supplied in a water-containing format, include, for example, a gel, cream, lotion, or emulsion. The skincare composition of the invention may be in any form, including toners, lotions, creams, foams, scrubs, serums, or gels suitable for topical application to the skin. The composition may be a leave-on product, such as skin lotions, creams, lipsticks, makeup bases, mascara, sunless tanners, and sunscreens, or a rinse-off product, such as shower gels and toilet bars. It is preferred that the composition be a skin lotion or cream. ινΐΛ / a / zuzz / uio 11 a One such format is where the water-containing product is thickened using thickeners to form a gel. An oil-in-water emulsion, whether in lotion or cream form, is one in which the preferred composition includes a fatty acid. Lotions generally contain 3 to 8% fatty acids by weight. In particular, C12 to C20 fatty acids are preferred, and C14 to C10 fatty acids are also preferred. The preferred fatty acid is substantially (generally approximately 90 to 95%) a mixture of stearic and palmitic acids. A mixture of stearic and palmitic acids in a 55:45 weight ratio is known as hysteric acid. Preferably, the composition of the invention is supplied in the form of a vanishing cream. A vanishing cream is one that, when applied and rubbed into human skin, disappears without leaving significant streaks of the composition. Fatty acids, when present in a composition together with a soap, provide the so-called vanishing cream effect. Preferably, the no-rinse composition comprises fatty acids having 10 to 30 carbon atoms, more preferably 12 to 25, even more preferably 14 to 20, with the highest preference being 16 to 18 carbon atoms. Examples of fatty acids that may be used in the composition include pelargonic, lauric, myristic, palmitic, stearic, isostearic, oleic, linoleic, arachidic, behenic, erucic acids, and mixtures thereof. Preferably, the fatty acid that may be used is stearic acid or palmitic acid, or a mixture thereof.The fatty acid in the present invention is preferably hysteric acid, which is substantially (generally about 90 to 95%) a mixture of stearic acid and palmitic acid in a ratio between 55:45 and 45:55. Preferably, the composition comprises 2.25 to 25% by weight, more preferably 4 to 22% by weight, even more preferably 6 to 20% by weight, with the highest preference 8 to 19% by weight and still more preferably 10 to 18% by weight and even more preferably 12 to 16% by weight of fatty acid. Preferably, the composition comprises soap. The soap, when present in combination with a fatty acid in the composition, provides the fading effect described above. Preferably, the soap in the composition is generally prepared by in-situ neutralization of the fatty acids that may be present in the composition. Therefore, it is preferable that the soap have a carbon chain length that corresponds to the chain length of the fatty acid in the composition. The soap is formed from the fatty acid by utilizing alkali metal hydroxides, for example, sodium hydroxide or potassium hydroxide. Of the two, potassium hydroxide is the more preferred. Therefore, the preferred soap is a potassium soap (potassium salt of fatty acid). Preferably, the composition comprises 0.1 to 10% by weight, more preferably 0.25% to 8% by weight, even more preferably 0.5 to 7% by weight, and even more preferably 0.5 to 5% by weight of soap, even with the maximum preference of 0.5% to 3%. The composition may include an emollient oil that acts as a co-solvent. Suitable emollient oils include, for example, alkoxylated aromatic alcohol esters with fatty carboxylic acids, polyglycol esters or diols with fatty carboxylic acids such as caprylic / capric triglyceride, fatty alcohol-fatty acid esters, alkoxylated benzyl alcohol derivatives, and mixtures thereof. Preferably, the emollient oil is caprylic / capric triglyceride. νΐΛ / 3 / 2υ22 / υΊ 011» Typically, such compositions comprise co-solvents in an amount of 0.01 to 10%, most preferably 0.1 to 8%, with the highest preference 1 to 6%, based on the total weight of the sun protection composition and including all variations contained therein. Creams are those whose composition generally comprises 8 to 24% by weight of fatty acids. Some of the fatty acid may be neutralized to form soap, which may be present from 1 to 10% by weight of the composition. A cosmetically acceptable base is typically 10 to 99.9%, preferably 50 to 99% by weight of the composition. A cosmetically acceptable base preferably includes water. The water content is preferably 35 to 90%, more preferably 50 to 85%, with the highest preference being 50 to 80% by weight of the composition. A water-in-oil emulsion may also be included as the cosmetically acceptable base. The cosmetically acceptable base in such emulsions generally comprises 5–50% silicone elastomer, preferably 10–30% by weight of the base. The silicone elastomer is preferably present at 1–15% by weight of the composition. Silicone elastomers differ from linear polymers due to crosslinking. Many silicone elastomers are made from linear silicone polymers containing reactive sites along the polymer chain. Elastomers have very different physical and chemical properties from linear polymers, and these properties are highly dependent on the number of crosslinks. An elastomer with a relatively small number of crosslinks will be very soft and will swell significantly in the presence of a compatible solvent. As the number of crosslinks increases, the elastomer's hardness increases, and it will swell to a lesser extent in the presence of the solvent. A silicone elastomer well-suited for use in the composition of the invention is DC 9045, a commercially available dimethicone crosspolymer from Dow Corning.DC 9045 is chemically a mixture of cyclopentasiloxane swelling agent and dimethicone crosspolymer (12-13%). The preferred swelling agent is a silicone fluid or a functional silicone fluid. The preferred swelling agent is used in a weight ratio of 1:10 to 10:1, most preferably 1:1 to 5:1, with respect to the reaction mixture used to prepare the silicone elastomer. The preferred swelling agent is a low-molecular-weight silicone oil, including (i) low-molecular-weight linear and cyclic volatile methylsiloxanes, (ii) low-molecular-weight linear and cyclic volatile and non-volatile alkyl- and arylsiloxanes, and (iii) low-molecular-weight linear and cyclic functional siloxanes. However, low-molecular-weight (VMS) linear and cyclic volatile methylsiloxanes are preferred. "Low molecular weight" in this paragraph means a compound having a molecular weight of 1000 to 9000. Other useful blends of silicone elastomers that can be used in the present invention are commercially available as (i) DC 9027 (a blend of ultra-high viscosity dimethiconol and silicone elastomer in cyclopentasiloxane) available from Dow Corning; (ii) DC 9546 (a blend of high molecular weight silicone elastomer, cyclopentasiloxane, and a high molecular weight linear silicone polymer) available from Dow Corning; (iii) EL8050 (a blend of high molecular weight polyglycol-modified silicone elastomer in isododecane) available from Dow Corning; and (iv) EL8051 (a blend of ML / 3 / 2622 / 6Ί 0116 high molecular weight polyglycol modified silicone elastomer in isodecyl neopentanoate) available from Dow Corning. Said water-in-oil emulsion composition preferably comprises 10 to 70%, most preferably 30 to 50% by weight of water in the composition. The useful sunscreen agents, for example, in the present invention, may preferably be used as an inorganic sunscreen. These include, for example, zinc oxide, iron oxide, silica, such as fumed silica, or titanium dioxide. The total amount of inorganic sunscreen preferably incorporated into the composition according to the invention is 1 to 8%, preferably 3 to 8% by weight of the composition. It has been observed that the inclusion of an inorganic sunscreen provides an additional synergistic benefit in SPF beyond the essential ingredients of the present invention. The composition of the invention may comprise a UV-A sunscreen agent selected from the group consisting of a dibenzoylmethane derivative, a triazine derivative, a benzophenone derivative, and mixtures thereof.In a preferred embodiment, the UV-A sunscreen agent comprises or is a dibenzoylmethane derivative, e.g., butylmethoxydibenzoylmethane (sold under the trade name Parsol 1789). Typically, the composition of the sunscreen of the present invention comprises from 0.1 to 15% by weight of the UV-A sunscreen agent, most preferably from 0.1 to 10%, with the highest preference from 1 to 5%, based on the total weight of the composition and including all variations included therein. The composition of the invention may also comprise a UV-B sunscreen agent. The suitable UV-B sunscreen agent of the invention is selected from the group consisting of a benzophenone, an anthranilate, a salicylate, a cinnamate, a camphor, benzylidene malonate, a triazone, and derivatives thereof. In a preferred embodiment, the UV-B sunscreen agent comprises or is a cinnamate derivative, for example, ethylhexyl methoxycinnamate (sold under the trade name Parsol MCX). Typically, the composition comprises 0.1 to 20% by weight of the UV-B sunscreen agent, most preferably 0.5 to 18%, most preferably 1 to 15%, based on the total weight of the composition and including all variations included therein. The composition of the invention may further comprise a skin-brightening agent. The skin-brightening agent is preferably selected from a vitamin B3 compound or derivative thereof, for example, niacin, nicotinic acid, niacinamide, or other well-known skin-brightening agents, for example, aloe extract, ammonium lactate, azelaic acid, kojic acid, citrate esters, ellagic acid, glycolic acid, green tea extract, hydroquinone, lemon extract, linoleic acid, magnesium ascorbyl phosphate, vitamins such as vitamin B6, vitamin B12, vitamin C, vitamin A, a dicarboxylic acid, resorcinol derivatives, hydroxycarboxylic acids such as lactic acid and its salts, for example, sodium lactate, and mixtures thereof.The vitamin B3 compound or its derivative, for example, niacin, nicotinic acid, and niacinamide according to the invention, are the most preferred skin brightening agents, with niacinamide being the most preferred. When used, niacinamide is preferably present in an amount ranging from 0.1 to 10%, most preferably from 0.2 to 5% by weight of the composition. The composition according to the invention may also comprise other diluents. The diluents act as dispersants or carriers for other materials present in the composition, to facilitate their distribution when the composition is applied to the skin. Diluents other than water may include liquid or solid emollients, solvents, humectants, thickeners, and powders. The compositions of the present invention may comprise a wide range of other optional components. The CTFA Cosmetic Ingredient Handbook, Second Edition, 1992, which is incorporated herein by reference in its entirety, describes a wide variety of non-limiting cosmetic and pharmaceutical ingredients commonly used in the skin care industry that are suitable for use in the compositions of the present invention. Examples include: antioxidants, binders, biological additives, buffering agents, colorants, thickeners, polymers, astringents, fragrances, humectants, opacifying agents, conditioners, exfoliating agents, pH adjusters, preservatives, natural extracts, essential oils, skin relaxants, skin soothing agents, and skin healing agents. Another aspect of the present invention relates to a composition according to the first aspect for reducing skin odor when the composition is applied to the desired skin surface. The preferred method is non-therapeutic. According to yet another aspect, a composition is described in accordance with the first aspect to provide an anti-acne benefit to the skin when the composition of the invention is applied to the desired skin surface. The invention will now be illustrated with the help of the following non-limiting examples: Examples Examples AD, 1: Effect of various active ingredients and combinations of active ingredients on malodor measured using a malodor reduction assay: The assets shown in Table 1 below were subjected to a test for odor reduction as described below: Odor testing using the lead acetate method: Bacterial culture preparation: S. hominis is the key bacterium responsible for thiol-mediated body odor, and therefore, the test organism used in this study was S. hominis ATOO 27844. Test organisms were cultured on TSA (Tryptic Soy Agar) plates overnight (22 ± 2 h). The organism was not removed more than three times from the original source. The cell count was adjusted by resuspending it in an appropriate amount of physiological saline solution sufficient to achieve the required cell count based on the optical density of the cells. The optical density (OD at 620 nM) of the cells was standardized to the cell count for the test organism using a spectrophotometer. A minimum final suspension of 1.0 x 10⁸ CFU / mL was achieved by adjusting the OD to 0.2 in saline solution for the odor assay. Preparation of lead acetate paper: A 1% lead acetate solution was prepared in distilled water. Whatmann filter paper (cut to a size that could be placed over the wells of a well plate) was immersed in the lead acetate solution. Excess solution was drained off, and the paper was allowed to dry in laminar airflow for 30 minutes. Preparation of active stock solutions: Stock solutions of the active ingredients were prepared for the assay. A 1:1 mixture of thymol and terpineol was prepared by weighing equal amounts of both materials (10 g of each) and mixing them on a magnetic stirrer for 4–5 hours. A 0.5% stock solution of this mixture was then prepared in ethanol by weighing 0.5 g of the mixture and diluting to 100 mL with ethanol. A 0.5% hexylresorcinol stock solution was prepared in ethanol and then diluted 1:10 in sterile distilled water to obtain a 0.05% hexylresorcinol stock solution. Test protocol: The malodor assay was adapted from the method of Moore et al., 2003 and modified for a 96-well plate format. 100 mL of Tryptic Soy Broth (TSB) with 0.1% L-cysteine-HCl was added to the wells of the 96-well plate. Subsequently, 20 mL of 0.2 OD culture of S. hominis was added to the wells. The active ingredients from the stock solutions were added at the required concentrations, and the volume was brought up to 200 mL with the addition of sterile distilled water. The assay was performed in triplicate. Lead acetate paper was placed over the wells, the lid of the 96-well plate was closed, and it was incubated overnight at 37°C. After the incubation period, the lead acetate paper was observed to have darkened. The visible blackening of lead acetate in the area above the well indicated the presence of H2S. The color intensity was recorded using a reflectometer as L*a*b* values.The difference between the initial and final ΔE values ​​of L*a*b* was used to quantify the formation of bad odors. ΔΕ = - afy + ( / ;, - bfy ινΐΛ / a / zuzz / u 1 ο ι ί a The percentage of malodor was calculated from the ΔE measured using the previous test for the various active ingredients or combinations. The results are summarized in Table 1 below: Table 1 Example Active (% by weight) Odor Generation (%) Disp. Est. A Control 100 — B Hexylresorcinol (0.0005%) 96 0.04 C Hexylresorcinol (0.001%) 96 0.11 D Thymol (0.005%) + Terpineol (0.005%) 78 0.04 I Hexylresorcinol (0.001%) + Thymol (0.005%) + Terpineol (0.005%) 21 1.50 The data in the table above indicate that the composition according to the present invention (Example 1) is synergistic over the individual values ​​delivered by hexylresorcinol alone or a combination of thymol and terpineol alone (Examples C and D).

Claims

1. An antimicrobial composition characterized in that it comprises: (i) alkyl-substituted dihydroxybenzene, wherein the alkyl group comprises from 2 to 10 carbon atoms; (ii) from 0.005 to 1% of an essential oil compound selected from thymol or terpineol, by weight of the composition; and (iii) a cosmetically acceptable base wherein the cosmetically acceptable base comprises a gel, emulsion, lotion, paste, spray, or cream; or wherein the cosmetically acceptable base is anhydrous and comprises a silicone compound, an alcohol, or a wax.

2. The composition according to claim 1, further characterized in that the alkyl-substituted dihydroxybenzene comprises from 2 to 6 carbon atoms.

3. The composition according to claim 1 or 2, further characterized in that the alkyl-substituted dihydroxybenzene is a hexylresorcinol having the chemical structure 4. The composition according to any of the preceding claims, further characterized in that the composition comprises a mixture of thymol and terpineol.

5. The composition according to any of the preceding claims, further characterized in that it comprises from 0.0005 to 10% alkyl-substituted dihydroxybenzene, by weight of the composition.

6. The composition according to any of the preceding claims, further characterized in that when the base is anhydrous, it is in the form of a bar or is supplied from a roll-on device or is supplied from an aerosol can or as a sprayer.

7. The composition according to any of the preceding claims, further characterized in that when the base is anhydrous, it is in the form of a disinfectant comprising more than 60% by weight of ethanol.

8. An antimicrobial composition as claimed in any of the preceding claims, for use in providing odor reduction on the skin, wherein the composition is adapted to be applicable to a desired skin surface.

9. An antimicrobial composition as claimed in any of claims 1 to 7, for use in providing an anti-acne benefit, wherein the composition is adapted to be applicable to a desired skin surface.