Antimicrobial composition comprising an alkylene glycol ester producing a biocidal or biostatic effect on microorganisms on the skin

Abstract

An antimicrobial composition is disclosed that contains a potentiator for an anti-dandruff active, an anti-malodor active, and / or an anti-acne active. The potentiator comprises one or more alkylene glycol esters.

Description

[0001] Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) ANTIMICROBIAL COMPOSITION PRODUCING A BIOCIDAL OR BIOSTATIC EFFECT ON MICROORGANISMS ON THE SKIN RELATED APPLICATIONS The present application is based upon and claims priority to U.S. Provisional Application Serial No.63 / 683,842, having a filing date of August 16, 2024, which is incorporated herein by reference. BACKGROUND

[0001] The skin hosts a complex ecosystem of microorganisms. The microorganisms include bacteria, fungi, viruses and archaea. The different microorganisms play a role in maintaining skin health. For instance, various bacteria on the skin help protect against pathogenic bacteria. Some microorganisms that are present on the skin, however, can lead to undesirable conditions. For example, Malassezia fungi, is associated with dandruff formation. Dandruff is characterized by a flakey and itchy scalp skin condition.

[0002] Acne is a common skin condition involving clogged hair follicles and sebaceous glands, leading to the formation of pimples, blackheads, and cysts. Although acne is caused by various different factors, acne is often associated with the presence of Cutibacterium acnes and / or Propionibacterium acnes bacteria.

[0003] Bacteria can also cause unwanted body odor. Body odor, for instance, results from bacteria breaking down sweat into acids. The apocrine glands found in areas like the armpits, for instance, produce a protein-rich sweat that bacteria feed on leading to odor.

[0004] Various different products are currently available for treating skin ailments, including dandruff, acne, and body odor. For example, various dandruff shampoos are available that contain an anti-dandruff active for controlling the growth of microorganisms that cause dandruff. Similarly, various anti-acne products are available that contain one or more antimicrobials in combination with other skin treatments. Body odor, on the other hand, is typically treated using deodorants. Deodorants can also contain antimicrobial agents that are effective against microorganisms that cause malodor. 1    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00)

[0005] Although the above products have met with great success in controlling skin conditions and other adverse ailments, further improvements are needed. For instance, not only are the actives incorporated into these products expensive, but also can cause skin irritation or allergy when used in higher concentrations. In fact, many of these actives are subject to environmental toxicity and regulatory restrictions that place limitations on the amount in which they can be incorporated into a product. At approved concentrations, however, antimicrobial efficacy may be decreased.

[0006] In view of the above, a need exists for an antimicrobial composition for treating one or more skin conditions that has enhanced efficacy against the microorganisms that cause the conditions. SUMMARY

[0007] In general, the present disclosure is directed to a skin or a scalp health composition that can be used to treat various skin ailments or conditions, including dandruff, acne, and / or malodor. In accordance with the present disclosure, an alkylene glycol ester is combined with an antimicrobial active in a manner that causes the antimicrobial active to increase in efficacy. In other words, the alkylene glycol ester serves as a booster for the antimicrobial agent in producing a biocidal or bacterial static effect against at least one microorganism located on the skin or on the scalp of the user.

[0008] In one aspect, for instance, the present disclosure is directed to an antimicrobial composition for producing a biocidal or biostatic effect on microorganisms on a skin or on a scalp of a user. The antimicrobial composition can have anti-dandruff, anti-malodor, and / or anti-acne properties. The antimicrobial composition comprises at least one antimicrobial compound in combination with an alkylene glycol ester. The at least one antimicrobial compound is configured to produce the biocidal or biostatic effect against at least one microorganism that causes dandruff, body odor, and / or acne.

[0009] For instance, in one aspect, the composition is formulated for anti- dandruff activity. The at least one antimicrobial compound contained in the composition can comprise piroctone olamine, zinc pyrithione, salicylic acid and salts thereof, climbazole, ketaconazole, hydroxyacetophenone, selenium sulphide, 2    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) coal tar, or mixtures thereof. When the composition is formulated to minimize the symptoms associated with dandruff, the biocidal or biostatic effect can occur against Malassezia Spp., including Malassezia globosa, Malassezia furfur, Malassezia sympodialis, Malassezia pachydermatis and / or Malassezia restricta.

[0010] In one aspect, the composition can be formulated to treat acne. In this embodiment, the at least one antimicrobial compound contained in the composition comprises salicylic acid and salts thereof, dehydroacetic acid and salts thereof, benzoyl peroxide, glycolic acid and salts thereof, azelaic acid and salts thereof, hydroxyacetophenone, gluconolactone, niacinamide, or mixtures thereof.

[0011] When used to treat acne, the composition can be formulated in order to produce a biocidal or biostatic effect against the growth of microorganisms associated with acne including Cutibacterium acnes, Staphylococcus epidermidis, and / or Propionibacterium acnes.

[0012] In another aspect, the composition of the present disclosure can be formulated to prevent body odor and the at least one antimicrobial compound contained in the composition can comprise zinc oxide, zinc citrate, zinc pyrrolidone carboxylic acid (zinc PCA), zinc glycinate, aluminum sulphate, aluminum zirconium, aluminum chloride, aluminum chlorohydrate, other aluminum salts, benzyl alcohol, phenoxyethanol, ethylhexyl glycerin, farnesol, geraniol, caprylyl glycol, octenidine dihydrochloride, or mixtures thereof. When formulated to treat body odor, the composition can produce a biocidal or biostatic effect against the growth of microorganisms associated with body odor including Corynebacterium striatum, Corynebacterium jeikeium, Corynebacterium xerosis, Staphylococcus hominis, Staphylococcus epidermidis, and / or Micrococcus luteus.

[0013] In accordance with the present disclosure, the alkylene glycol ester and the antimicrobial compound are present in a synergistically effective amount. The alkylene glycol ester can comprise a propylene glycol ester, such as propylene glycol caprylate, and particularly propylene glycol monocaprylate. The alkylene glycol ester can also comprise an ethylene glycol ester, such as ethylene glycol caprylate, and in particular ethylene glycol monocaprylate. In various embodiments, the alkylene glycol ester can comprise alkylene glycol monoester, alkylene glycol diester, or mixtures thereof, preferably comprising propylene glycol 3    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) monoester, propylene glycol diester, or mixtures thereof, more preferably comprising propylene glycol monocaprylate, propylene glycol dicaprylate, or mixtures thereof, and in particular a mixture of propylene glycol monocaprylate and propylene glycol dicaprylate or propylene glycol monocaprylate.

[0014] In one embodiment, the alkylene glycol ester is a mixture of propylene glycol monocaprylate and propylene glycol dicaprylate comprising at least 10 wt.- %, preferably at least 30 wt.-%, and in particular at least 60 wt.-%, of the propylene glycol monocaprylate, based on the weight sum of propylene glycol monocaprylate and propylene glycol dicaprylate.

[0015] The alkylene glycol ester and the antimicrobial compound can be present in the composition in a weight ratio of about 1:1000 to about 2500:1, or about 1:1000 to about 2000:1, or about 1:1000 to about 1500:1, or about 1:1000 to about 500:1, or about 1:1000 to about 50:1, or about 1:800 to about 200:1, or about 1:800 to about 40:1, or about 1:600 to about 150:1, or about 1:600 to about 30:1, or about 1:550 to about 100:1, or about 1:550 to about 20:1, or about 1:250 to about 15:1, or about 1:100 to about 10:1.

[0016] The present disclosure is also directed to various different personal care products incorporating the antimicrobial composition of the present disclosure. The personal care product, for instance, can be for topical application to a user’s skin or scalp. The antimicrobial composition can be present in the personal care product in an amount from about 0.0005% by weight to about 10% by weight based on the total weight of the personal care product. The personal care product can comprise an anti-dandruff personal care product, an anti-acne personal care product, or a deodorant.

[0017] The present disclosure is also directed to a method for producing a biocidal or biostatic effect on microorganisms on a skin or on a scalp of a user. The method includes applying to a skin of a user an antimicrobial composition as described above. In one aspect, the antimicrobial composition comprises alkylene glycol ester and at least one antimicrobial compound comprising piroctone olamine, zinc pyrithione, salicylic acid and salts thereof, gluconolactone, ethylhexyl glycerin, climbazole, caprylyl glycol, hydroxyacteophenone, azelaic acid, zinc oxide, zinc citrate, zinc pyrrolidone carboxylic acid (zinc PCA), zinc glycinate, other 4    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) zinc salts, niacinamide, benzoyl peroxide, ketaconazole, selenium sulphide, coal tar, dehydroacetic acid and salts thereof, glycolic acid and salts thereof, benzyl alcohol, phenoxyethanol, farnesol, geraniol, octenidine dihydrochloride, or mixtures thereof.

[0018] In one aspect, the antimicrobial composition is applied to the underarms of a user. Alternatively, the antimicrobial composition can be applied to the face of a user. In another aspect, the antimicrobial composition can also be applied to the scalp of a user.

[0019] Other features and aspects of the present disclosure are discussed in greater detail below. DEFINITIONS

[0020] In order for the present invention to be readily understood, several definitions of terms used in the course of the invention are set forth below.

[0021] In general, the present invention is directed to an antimicrobial composition. As used herein, the term “antimicrobial compound” means a biocidal or biostatic agent or biocidal composition which is intended to be blended with into an end-use formulation, such as a personal care formulation intended to be applied to the skin (including the scalp of the user) for reducing and / or controlling the growth of targeted microorganisms on the skin, which can prevent or treat various skin ailments including dandruff, acne, or body odor.

[0022] It has now been surprisingly found that adding an amount of an alkylene glycol ester to antimicrobial compound(s) intended for an end-use formulation can provide an effective antimicrobial end-use formulation with a synergistic interaction between the antimicrobial compound(s) and the alkylene glycol ester. As used herein, a “synergistic interaction” refers to the fact that the antimicrobial compound(s), when combined with the alkylene glycol ester has a total antimicrobial / antifungal effect that is greater than the antimicrobial / antifungal properties of the antimicrobial compound(s) alone, or the alkylene glycol ester alone. In other words, the antimicrobial compound(s) of the present invention operates synergistically with the alkylene glycol ester so as to have greater antimicrobial / antifungal activity in the presence of each against certain microorganisms than in comparison to the antimicrobial activity of the antimicrobial 5    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) compound(s) alone or the antimicrobial activity of the alkylene glycol ester alone at the same concentrations. Due to the synergistic effect, the amount of the antimicrobial compound(s) present in the antimicrobial composition can be reduced while still producing the desired efficacy. This effect is also known as “potentiation” of the antimicrobial compound(s) in the antimicrobial composition. This potentiation of the antimicrobial compound(s) is also referred to herein as a “synergistic effect” between the antimicrobial compound(s) and the alkylene glycol ester(s) for boosting the efficacy of the antimicrobial compound(s).

[0023] Further, use of the antimicrobial composition disclosed herein provides numerous technical advantages and benefits. For example, the antimicrobial composition(s) disclosed herein can maintain antibacterial and / or antifungal activity at various pH levels. Furthermore, the antimicrobial composition(s) disclosed herein generally remain stable during changes in temperature and changes encountered during manufacturing, packaging, shipping, and storage of the end- formulation in which the antimicrobial composition may be included. Further, the antimicrobial composition(s) disclosed herein are physically and chemically compatible with ingredients present in various end-use formulations. Lastly, as described further herein, the antimicrobial composition(s) of the present invention may contain lesser amounts of an antimicrobial compound yet still provide antimicrobial efficacy consistent with industry standards.

[0024] The term “alkyl” as used herein denotes in each case a straight-chain or branched saturated hydrocarbon group having usually from 1 to 8 carbon atoms, preferably 1 to 6 or 1 to 4 carbon atoms, more preferably 1 to 3 or 1 to 2 or 1 carbon atoms. Examples of an alkyl group are methyl, ethyl, n-propyl, iso-propyl, n-butyl, 2-butyl, iso-butyl, tert-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3- methyl-butyl, 2,2-dimethylpropyl, 1-ethylpropyl, n-hexyl, 1,1-dimethylpropyl, 1,2- dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethyl-butyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3- dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethyl-1-methylpropyl, 1-ethyl-2-methylpropyl, and the like.

[0025] The term “alkenyl” as used herein denotes in each case a straight-chain or branched hydrocarbon group having usually from 2 to 18 carbon atoms, 6    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) frequently from 2 to 8 or 2 to 6 carbon atoms, with one or more C=C double bonds. The alkenyl moieties, where appropriate, can be of either the (E)- or (Z)- configuration.

[0026] The term “alkynyl” as used herein denotes in each case a straight-chain or branched hydrocarbon group having usually from 2 to 18 carbon atoms, frequently from 2 to 8, 2 to 6, or 2 to 4 carbon atoms, with one or more C≡C triple bonds.

[0027] The term “cycloalkyl” as used herein refers to a saturated bi- or monocyclic hydrocarbon that has – in general and if not defined otherwise in the specification – a single point of attachment to the remainder of the molecule, with 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 ring carbon atoms. C3-8- cycloalkyl groups may be unsubstituted or substituted with - unless specified differently elsewhere in this specification - 1 , 2 or 3 substituents that may be the same of different and are - unless specified differently elsewhere in this specification - selected from the group comprising C1-6-alkyl, C1-6-alkoxy, halogen, hydroxy, unsubstituted or mono- or di-substituted amino. Exemplary cycloalkyl groups are cyclopentyl, cyclohexyl, and cycloheptyl.

[0028] The term “aryl” (either alone or as part of a larger group, such as e.g. aryloxy) as used herein refers to aromatic ring systems (i.e. fulfilling the Hückel rule – having (4n+π2) electrons, with n being 0 or an integer of preferably 1 to 3) which can be in mono-, bi- or tricyclic form. Examples of such rings include phenyl, naphthyl, or indenyl. Preferred aryl groups are phenyl and naphthyl, phenyl being most preferred. A suitable example for aryloxy rings includes phenoxy.

[0029] The term “alkoxy” as used herein denotes in each case alkyl substituents as defined above that are connected to another structural moiety via an oxygen atom (-O-). Exemplary alkoxy groups are methoxy, trifluoromethoxy, ethoxy, 2,2,2-trifluoroethoxy, n-propoxy, iso-propoxy, n-butoxy, sec-butoxy, tert- butoxy, n-pentoxy.

[0030] The organic moieties mentioned in the above definitions of the variables are - like the term halogen - collective terms for individual listings of the individual 7    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) group members. The prefix Cn-Cm (as well as Cn to Cm or Cn-m) indicates in each case the possible number of carbon atoms in the group.

[0031] The term “carbonyl” as used herein denotes a carbonyl moiety, also known as “C(O)” or “C=O”.

[0032] The term “halogen” denotes in each case fluorine, bromine, chlorine, or iodine.

[0033] As used herein, the articles “a” and “an” preceding an element or component are intended to be nonrestrictive regarding the number of instances (i.e. occurrences) of the element or component. Therefore, “a” or “an” is to be read to include one or at least one, and the singular word form of the element or component also includes the plural unless the number is obviously meant to be singular.

[0034] As used herein, the term “about” modifying the quantity of a substance, ingredient, component, or parameter employed refers to variation in the numerical quantity that can occur, for example, through typical measuring and handling procedures, e.g., liquid handling procedures used for making concentrates or solutions. Furthermore, variation can occur from inadvertent error in measuring procedures, differences in the manufacture, source, or purity of the ingredients employed to carry out the invention. In one embodiment, the term “about” means within 10% of the reported numerical value. In a more specific embodiment, the term “about” means within 5% of the reported numerical value.

[0035] As used herein, the salts of an antimicrobial compound, such as salicylic acid, azelaic acid, dehydroacetic acid, glycolic acid, may be any salts thereof known in the art. Suitable cationic counterions are e.g. the ions of alkali metals, preferably lithium, sodium and potassium, of the alkaline earth metals, preferably calcium, magnesium and barium, and of the transition metals preferably manganese, copper, silver, zinc and iron, and also ammonium (NH4+) and substituted ammonium in which one to four of the hydrogen atoms are replaced by C1-C4-alkyl, C1-C4-hydroxyalkyl, C1-C4-alkoxy, C1-C4-alkoxy-C1-C4alkyl, hydroxy-C1-C4-alkoxy-C1-C4-alkyl, phenyl or benzyl. Suitably, the salt of said acids is the sodium salt such as the salt of salicylic acid is sodium salicylate. 8    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) DETAILED DESCRIPTION

[0036] It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present disclosure.

[0037] Skin health conditions, such as dandruff, acne, and malodor, are widespread, driving significant market demand for preventative and corrective treatments. Although various skin actives are available for treating various skin ailments, the actives can be very expensive for incorporating into a product and are typically subject to governmental regulations that limit the amount of actives contained in the products. Thus, there is constant pressure to develop skincare products that have enhanced efficacy against microorganisms that cause skin conditions, including dandruff, acne, and body odor.

[0038] In accordance with the present disclosure, it was discovered that a particular potentiator can dramatically increase the efficacy of many of the actives that are used in skincare products. In particular, it was discovered that one or more alkylene glycol esters can potentiate many different antimicrobial actives used for anti-dandruff, anti-acne, and anti-malodor against the microorganisms which cause each of these conditions.

[0039] For instance, in one aspect, the present disclosure is directed to an antimicrobial composition that is formulated to display anti-dandruff activity. The antimicrobial composition contains a potentiator which comprises at least one alkylene glycol ester in combination with an antimicrobial compound that is capable of destroying or controlling the growth of the fungi responsible for dandruff. For instance, the antimicrobial composition can be formulated in order to produce a biocidal or biostatic effect against the growth of microorganisms associated with dandruff which include Malassezia globosa, Malassezia furfur, Malassezia sympodialis, Malassezia pachydermatis and / or Malassezia restricta. For instance, when contacted with one or more of the above microorganisms, the antimicrobial composition of the present disclosure can display greater than a log 0.5 reduction, such as greater that a log 1 reduction, such as greater that a log 2 reduction, such as greater than a log 3 reduction, such as even greater than a log 9    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) 4 reduction when contacted with the microorganisms for 24 hours or even after 4 hours.

[0040] The anti-dandruff active contained within the antimicrobial composition can comprise, for instance, a pyrithione such as zinc pyrithione, an olamine such as piroctone olamine, salicylic acid and salts thereof, climbazole, ketaconazole, hydroxyacetophenone, selenium sulphide, coal tar, or mixtures thereof.

[0041] In another aspect, the antimicrobial composition is formulated to treat acne. For instance, the antimicrobial composition can contain at least one antimicrobial compound that, in combination with the alkylene glycol ester, produces a biocidal or biostatic effect against microorganisms that cause or are associated with acne including Cutibacterium acnes, Staphylococcus epidermidis, and / or Propionibacterium acnes. For example, the antimicrobial composition formulated to treat acne can contain one or more alkylene glycol esters in combination with at least one anti-acne that can comprise salicylic acid and salts thereof, dehydroacetic acid and salts thereof, benzoyl peroxide, glycolic acid and salts thereof, azelaic acid and salts thereof, hydroxyacetophenone, gluconolactone, niacinamide, or mixtures thereof.

[0042] In still another aspect, the present disclosure is directed to an antimicrobial composition that is formulated to prevent body odor. For instance, the antimicrobial composition can contain an active against microorganisms that cause body odor in combination with an alkylene glycol ester that together produce a biocidal or biostatic effect against the growth of microorganisms associated with body odor. For instance, the antimicrobial composition can be effective against Corynebacterium striatum, Corynebacterium jeikeium, Corynebacterium xerosis, Staphylococcus hominis, Staphylococcus epidermidis, and / or Micrococcus luteus.

[0043] When formulated to prevent body odor, the alkylene glycol ester can be combined with various different antimicrobial compounds. The antimicrobial compounds include zinc oxide, zinc citrate, zinc pyrrolidone carboxylic acid (zinc PCA), zinc glycinate, aluminum sulphate, aluminum zirconium, aluminum chloride, aluminum chlorohydrate, other aluminum salts, benzyl alcohol, phenoxyethanol, ethylhexyl glycerin, farnesol, geraniol, caprylyl glycol, octenidine dihydrochloride, or mixtures thereof. 10    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00)

[0044] When the alkylene glycol ester is combined with one or more of the above antimicrobial compounds, a synergistic action can occur that boosts the efficacy of the antimicrobial compound against the one or more microorganisms. In certain formulations, the synergistic interaction can be dramatic. Thus, products can be formulated containing reduced amounts of the antimicrobial compound while still having the same or increased effectiveness against one or more target organisms. Ultimately, products can be formed that have enhanced anti-dandruff effect, enhanced anti-acne effect, or enhanced anti-malodor effect.

[0045] As described above, the potentiator of the present disclosure comprises an alkylene glycol ester that is combined with one or more antimicrobial compounds.

[0046] Alkylene glycol esters useable in the present invention may be formed from saturated, unsaturated, natural or synthetic fatty acids, and the like. For instance, saturated fatty acids include caprylic acid, capric acid, hexanoic acid, dodecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, nonanoic acid, combinations thereof, derivatives thereof, and the like. Fatty acids having a carbon chain length of from about 5 carbon atoms to about 16 carbon atoms are well suited for use in forming the alkylene glycol ester. The alkylene glycol ester can be formed from any suitable alkylene, such as ethylene or propylene. The alkylene glycol ester can comprise a monoester or a diester. In one aspect, a mixture of monoesters, a mixture of diesters, or a mixture of monoesters and diesters may be incorporated into the composition of the present invention. In one aspect, at least one monoester is utilized and comprises the majority of the alkylene glycol ester present.

[0047] In some embodiments, the alkylene glycol ester(s) is derived from (a) a propylene glycol, or ethylene glycol component, and (b) a fatty acid having from about 6 to 12 carbon atoms, such as caproic acid, caprylic acid, capric acid, lauric acid, and mixtures of the like. For example, propylene glycol C6-C12 fatty acid monoesters or diesters may be used. Propylene glycol C6-C14 fatty acid monoesters or diesters may also be used. 11    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00)

[0048] Suitable examples of alkylene glycol esters, include but are not limited to, propylene glycol isostearate, propylene glycol laurate, propylene glycol myristate, propylene glycol oleate, propylene glycol monolaurate, propylene glycol monocaprate, propylene glycol monocaprylate, propylene glycol monocaproate, propylene glycol diperlargonate, propylene glycol diisostearate, propylene glycol dilaurate, propylene glycol monopalmitate, propylene glycol monostearate, ethylene glycol isostearate, ethylene glycol laurate, ethylene glycol myristate, ethylene glycol oleate, ethylene glycol monolaurate, ethylene glycol monocaprate, ethylene glycol monocaprylate, ethylene glycol monocaproate, ethylene glycol diperlargonate, ethylene glycol diisostearate, ethylene glycol dilaurate, ethylene glycol monopalmitate, ethylene glycol monostearate, or mixtures thereof, other complexes or derivatives thereof, and the like.

[0049] A suitable example of an alkylene glycol diester is propylene glycol dicaprylate.

[0050] In one embodiment, the alkylene glycol ester is primarily propylene glycol monocaprylate. The propylene glycol monocaprylate can include a mixture of propylene glycol monoesters and diesters. For example, the propylene glycol monocaprylate may contain 2-hydroxylpropyl caprylate (e.g. at least 40 wt.-%), octanoic acid-2-hydroxy-1-methylethyl ester (e.g.23 to 33 wt.-%), and 1,2- propylene glycol dicaprylate (e.g.5 to 28 wt.-%).

[0051] In one embodiment, the alkylene glycol ester comprises propylene glycol caprylate (PGC). In one embodiment, the alkylene glycol ester comprises a mixture of at least one propylene glycol monocaprylate and propylene glycol dicaprylate. In one embodiment, the alkylene glycol ester is of a mixture of at least one propylene glycol monocaprylate and propylene glycol dicaprylate. In one embodiment, the at least one propylene glycol monocaprylate is selected from octanoic acid-2-hydroxy-1-methylethyl ester, 2-hydroxylpropyl caprylate, and a combination thereof. In one embodiment, the at least one propylene glycol monocaprylate is a mixture of octanoic acid-2-hydroxy-1-methylethyl ester and 2- hydroxylpropyl caprylate. In one embodiment, the propylene glycol dicaprylate is 1,2-propylene glycol dicaprylate. In one embodiment, the alkylene glycol ester comprises at least 50 wt.-% of at least one propylene glycol monocaprylate, 12    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) preferably at least 60 wt.-% of at least one propylene glycol monocaprylate, more preferably at least 70 wt.-% of at least one propylene glycol monocaprylate, based on the total weight of the alkylene glycol ester. In one embodiment, the at least one propylene glycol monocaprylate and the propylene glycol dicaprylate are comprised in the mixture at a weight ratio of from 15:1 to 1:1, preferably at a weight ratio of from 10:1 to 1:1, more preferably at a weight ratio of from 5:1 to 2:1.

[0052] In one embodiment, the alkylene glycol ester comprises a mixture of octanoic acid-2-hydroxy-1-methylethyl ester, 2-hydroxylpropyl caprylate, and 1,2- propylene glycol dicaprylate. In one embodiment, the alkylene glycol ester comprises from 20 wt.-% to 35 wt.-% octanoic acid-2-hydroxy-1-methylethyl ester, from 40 wt.-% to 70 wt.-% 2-hydroxylpropyl caprylate, and from 5 wt.-% to 30 wt.- % 1,2-propylene glycol dicaprylate, based on the total weight of the alkylene glycol ester.

[0053] In one embodiment, the alkylene glycol ester comprises from 20 wt.-% to 30 wt.-% octanoic acid-2-hydroxy-1-methylethyl ester, from 40 wt.-% to 60 wt.-% 2- hydroxylpropyl caprylate, and from 20 wt.-% to 30 wt.-% 1,2-propylene glycol dicaprylate, based on the total weight of the alkylene glycol ester.

[0054] In one embodiment, the alkylene glycol ester comprises from 20 wt.-% to 40 wt.-% octanoic acid-2-hydroxy-1-methylethyl ester, from 50 wt.-% to 70 wt.-% 2- hydroxylpropyl caprylate, and from 5 wt.-% to 15 wt.-% 1,2-propylene glycol dicaprylate, based on the total weight of the alkylene glycol ester.

[0055] In one embodiment, said alkylene glycol ester comprises propylene glycol ester, preferably propylene glycol caprylate, and in particular propylene glycol monocaprylate. In one embodiment, said alkylene glycol ester is propylene glycol ester, such as propylene glycol caprylate or propylene glycol monocaprylate.

[0056] In one embodiment, said alkylene glycol ester comprises alkylene glycol caprylate such as selected from alkylene glycol monocaprylate, alkylene glycol dicaprylate, or mixtures thereof.

[0057] In one embodiment, said alkylene glycol ester is selected from alkylene glycol monoester, alkylene glycol diester, and mixtures thereof, preferably selected from propylene glycol monoester, propylene glycol diester, or mixtures thereof, and 13    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) in particular selected from propylene glycol monocaprylate, propylene glycol dicaprylate, or mixtures thereof.

[0058] In one embodiment, said alkylene glycol ester is a mixture of alkylene glycol monoester and alkylene glycol diester comprising at least 10 wt.-%, preferably at least 30 wt.-%, more preferably at least 50 wt.-%, still more preferably at least 60 wt.-%, and in particular at least 70 wt.-%, of the alkylene glycol monoester, based on the weight sum of alkylene glycol monoester and propylene glycol diester. In one embodiment, said alkylene glycol ester is a mixture of alkylene glycol monocaprylate and alkylene glycol dicaprylate comprising at least 10 wt.-%, preferably at least 30 wt.-%, more preferably at least 50 wt.-%, still more preferably at least 60 wt.-%, and in particular at least 70 wt.-%, of the alkylene glycol monocaprylate, based on the weight sum of alkylene glycol monocaprylate and propylene glycol dicaprylate. In one embodiment, said alkylene glycol ester is a mixture of propylene glycol monocaprylate and propylene glycol dicaprylate comprising at least 10 wt.-%, preferably at least 30 wt.-%, more preferably at least 50 wt.-%, still more preferably at least 60 wt.-%, and in particular at least 70 wt.-%, of the propylene glycol monocaprylate, based on the weight sum of propylene glycol monocaprylate and propylene glycol dicaprylate.

[0059] In one embodiment, said alkylene glycol ester comprises a mixture of at least one propylene glycol monocaprylate and propylene glycol dicaprylate. In one embodiment, said alkylene glycol ester comprises at least 50 wt.-% of at least one propylene glycol monocaprylate, preferably at least 60 wt.-% of at least one propylene glycol monocaprylate, more preferably at least 70 wt.-% of at least one propylene glycol monocaprylate, based on the total weight of the alkylene glycol ester. In one embodiment, the at least one propylene glycol monocaprylate and the propylene glycol dicaprylate are comprised in the mixture at a weight ratio of from about 15:1 to about 1:1, preferably at a weight ratio of from about 10:1 to about 1:1, more preferably at a weight ratio of from about 5:1 to about 2:1.

[0060] The weight ratio of the alkylene glycol ester and the at least one antimicrobial compound can vary depending on a variety of factors. For example, the weight ratio can depend on the skin condition being treated, the type of antimicrobial compound contained in the composition, the microorganisms that are 14    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) being controlled, and the particular alkylene glycol ester selected. In various embodiments, one or more alkylene glycol esters can be present in the antimicrobial composition in relation to one or more antimicrobial compounds at a weight ratio of from about 1:1000 to about 2500:1, such as from about 1:1000 to about 2000:1, such as from about 1:1000 to about 1500:1, such as from about 1:1000 to about 500:1, such as from about 1:1000 to about 50:1, such as from about 1:800 to about 200:1, such as from about 1:800 to about 40:1, such as from about 1:600 to about 50:1, such as from about 1:600 to about 30:1, such as from about 1:550 to about 100:1, such as from about 1:550 to about 20:1, such as from about 1:250 to about 15:1, such as from about 1:100 to about 10:1. In one aspect, the weight ratio of one or more alkylene glycol esters to one or more antimicrobial compounds can be from about 1:2 to about 5:1, such as from about 1:1.5 to about 3:1.

[0061] In one embodiment, the antimicrobial composition of the present disclosure contains at least one antimicrobial compound that comprises a salicylic acid or salt thereof, a pyrithione such as zinc pyrithione, climbazole, piroctone olamine or mixtures thereof. The alkylene glycol ester can comprise a propylene glycol ester, such as propylene glycol caprolate, and in particular a propylene glycol monocaprolate. Alternatively, the alkylene glycol ester can comprise an ethylene glycol ester, such as ethylene glycol caprolate and in particular ethylene glycol monocaprolate. In one embodiment, the alkylene glycol ester can comprise a mixture of propylene glycol monocaprolate and propylene glycol dicaprolate or a mixture of ethylene glycol monocaprolate and ethylene glycol dicaprolate.

[0062] Once the antimicrobial composition is formulated, the composition can be incorporated into a personal care product. The personal care product, for instance, can be formulated to treat dandruff, acne, and / or prevent body odor.

[0063] The base composition of the product may contain numerous and different ingredients depending upon the end use application. The personal care product formulation, for instance, may contain solvents, surfactants, emulsifiers, complexing agents, corrosion inhibitors, alkalinity builders, pH adjusting agents, auxiliaries, acids, foaming agents, colorants, UV blocking agents, waxes, natural extracts, oils, consistency factors, conditioners, emollients, skin caring ingredients, 15    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) moisturizers, thickeners, humectants, fillers, anti-oxidants, other preservatives, active ingredients, fragrances and the like, as well as mixtures thereof.

[0064] Suitable surfactants for the base composition comprise: alkyl sulfates e.g. sodium lauryl sulfate, ammonium lauryl sulfate; sodium cetearyl sulfate; alkyl sulfoacetates e.g. sodium lauryl sulfoacetate; alkyl ether sulfates e.g. sodium laureth sulfate; sodium trideceth sulfate; sodium oleth sulfate; ammonium laureth sulfate; alkyl ether sulfosuccinates e.g. disodium laureth sulfosuccinate; alkyl glycosides e.g. decyl glucoside; lauryl glucoside; alkyl isethionates amphoterics e.g. cocamidopropyl betaine; sodium cocoamphoacetate; sodium lauroamphoacetate; disodium lauroamphodiacetate; disodium cocoamphodiacetate; sodium lauroamphopripionate; disodium lauroamphodipropionate; potassium or ammonium salts of the aforementioned amphoterics; capryl / capramidopropyl betaine; undecylenamidopropyl betaine; lauromidopropyl betaine; and fatty alcohol polyglycol ethers.

[0065] Suitable emulsifiers for the base composition are e.g. anionics as salts of fatty acids e.g. sodium stearate or sodium palmitate, organic soaps e.g. mono-, di- or triethanolaminoeate, sulfated or sulfonated compounds e.g. sodium lauryl sulfate or sodium cetyl sulfonate, saponines, lamepones; cationics as quaternary ammonium salts; nonionics as fatty alcohols, fatty acid ester with saturated or unsaturated fatty acids, polyoxyethylenesters or polyoxyethylenethers of fatty acids, polymers from ethylene oxide and propylene oxide or propylene glycol, amphotherics as phosphatides, proteins as gelatine, casein alkylamidobetaines, alkyl betaines and amphoglycinates, alkyl phosphates, alkylpolyoxyethylene phosphates or the corresponding acids, silicone derivatives, e.g. alkyl dimethiconecoplyol.

[0066] Suitable consistency factors for the base composition are e.g. fatty alcohols or their mixtures with fatty acid esters, e.g. acetylated lanolin alcohol, aluminum stearates, carbomer, cetyl alcohol, glyceryl oleate, glyceryl stearate, glyceryl stearate (and) PEG 100 stearate, magnesium stearate, magnesium sulfate, oleic acid, stearic acid, stearyl alcohol, myristyl myristate, isopropyl palmitate, carnuba wax, beeswax and synthetic equivalents thereof, carbomers, and the like. Suitable conditioners are e.g. alkylamido ammonium lactate, 16    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) cetrimonium chloride and distearoylethyl hydroxyethylmonium methosulfate and cetearyl alcohol, cetyl dimethicone, cetyl ricinoleate, dimethicone, laureth-23, laureth-4, polydecene, retinyl palmitate, quaternized protein hydrolysates, quaternized cellulose and starch derivatives, quaternized copolymers of acrylic or methacrylic acid or salts, quaternized silicone derivatives.

[0067] Suitable emollients for the base composition are e.g. cetearyl isononanoate, cetearyl octanoate, decyl oleate, isooctyl stearate, coco caprylate / caprate, ethylhexyl hydroxystearate, ethylhexyl isononanoate, isopropyl isostearate, isopropyl myristate, oleyl oleate, hexyl laurate, paraffinum liquidum, PEG-75 lanolin, PEG-7 glyceryl cocoate, petrolatum, ozokerite cyclomethicone, dimethicone, dimethicone copolyol, dicaprylyl ether, butyrospermum parkii, buxus chinensis, canola, carnauba cera, copernicia cerifera, oenothera biennis, elaeis guineensis, prunus dulcis, squalane, zea mays, glycine soja, helianthus annuus, lanolin, hydrogenated castor oil, hydrogenated coconut oil, hydrogenated polyisobutene, sucrose cocoate, stearoxy dimethicone, lanolin alcohol, isohexadecane.

[0068] Suitable skin care ingredients for the base composition are e.g. plant extracts, bisabolol, anti-inflammatory agents, urea, allantoin, panthenol and panthenol derivatives, phytantriol, vitamins A, E, C, D, ceram ides of animal or plant origin, lecithins, and the like.

[0069] Suitable moisturizers for the base composition are e.g. butylenes glycol, cetyl alcohol, dimethicone, dimyristyl tartrate, glucose glycereth-26, glycerin, glyceryl stearate, hydrolyzed milk protein, lactic acid, lactose and other sugars, laureth-8, lecithin, octoxyglycerin, PEG-12, PEG 135, PEG-150, PEG-20, PEG-8, pentylene glycol, hexylene glycol, phytantriol, poly quaternium-39 PPG-20 methyl glucose ether, propylene glycol, sodium hyaluronate, sodium lactate, sodium PCA, sorbitol, succinoglycan, synthetic beeswax, tri-C14-15 alkyl citrate, starch.

[0070] Suitable thickeners for the base composition are e.g. acrylates / steareth- 20 methacrylate copolymer, carbomer, carboxymethyl starch, cera alba, dimethicone / vinyl dimethicone crosspolymer, propylene glycol alginate, hydroxyethylcellulose, hydroxypropyl methylcellulose, silica, silica dimethyl silylate, xanthan gum, hydrogenated butylenes / ethylene / styrene copolymer. 17    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00)

[0071] Suitable humectants for the base composition are e.g. adipic acid, fumaric acid and its salts, benzoic acid and its salts, glycerine triacetate, sodium or magnesium lauryl sulfate, magnesium stearate, solid polyethylenglycol, polyvinylpyrrolidone, boric acid, mono-laurate or mono-palmitate, myristyl alcohol, cetyl alcohol, cetylstearyl alcohol, talcum, calcium or magnesium salts of higher fatty acids, mono-, di- or triglycerides of higher fatty acids, polytetrafluorethylene.

[0072] Suitable antioxidants for the base composition are e.g. sulfites, e.g. sodium sulfite, tocopherol or derivates thereof, ascorbic acid or derivates thereof, citric acid, propyl gallate, chitosan glycolate, cysteine, N-acetyl cysteine plus zinc sulfate, thiosulfates, e.g. sodium thiosulfate, polyphenols and the like.

[0073] The formulations may further contain active ingredients in addition to one or more antimicrobial compounds as described above, e.g. antimicrobials, anti-inflammatories, plant extracts, bisabolol, panthenol, tocopherol, actives for anti-stinging, anti-irritant or anti-dandruff applications, or anti-aging agents such as retinol, melibiose and the like. Other suitable actives are e.g. Medicago officinalis, Actinidia chinensis, allantoin, Aloe barbadensis, Anona cherimolia, Anthemis nobilis, Arachis hypogaea, Arnica Montana, Avena sativa, beta-carotene, bisabolol, Borago officinalis, butylenes glycol, Calendula officinalis, Camellia sinensis, camphor, Candida bombicola, capryloyl glycine, Carica papaya, Centaurea cyanus, cetylpyridinium chloride, Chamomilla recutita, Chenopodium quinoa, Chinchona succirubra, Chondrus crispus, Citrus aurantium dulcis, Citrus grandis, Citrus limonum, Cocos nucifera, Coffea Arabica, Crataegus monogina, Cucumis melo, dichlorophenyl imidazoldioxolan, Enteromorpha compressa, Equisetum arvense, ethoxydiglycol, ethyl panthenol, farnesol, ferulic acid, Fragaria chiloensis, Gentiana lutea, Ginkgo biloba, glycerin, glyceryl laurate, Glycyrrhiza glabra, Hamamelis virginiana, heliotropine, hydrogenated palm glycerides, citrates, hydrolyzed castor oil, hydrolyzed wheat protein, Hypericum perforatum, Iris florentina, Juniperus communis, Lactis proteinum, lactose, Lawsonia inermis, linalool, Linum usitatissimum, lysine, magnesium aspartate, Magnifera indica, Malva sylvestris, mannitol, Melaleuca alternifolia, Mentha piperita, menthol, menthyl lactate, Mimosa tenuiflora, Nymphaea alba, olaflur, Oryza sativa, panthenol, paraffinum liquidum, PEG-20M, PEG-26 jojoba acid, PEG-26 jojoba 18    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) alcohol, PEG-35 castor oil, PEG-40 hydrogenated castor oil, PEG-60 hydrogenated castor oil, PEG-8 caprylic / capric acid, Persea gratissima, petrolatum, potassium aspartate, potassium sorbate, propylene glycol, Prunus amygdalus dulcis, Prunus armeniaca, Prunus persica, retinyl palmitate, Ricinus communis, Rosa canina, Rosmarinus officinalis, Rubus idaeus, salicylic acid, Sambucus nigra, sarcosine, Serenoa serrulata, Simmondsia chinensis, sodium carboxymethyl betaglucan, sodium cocoyl amino acids, sodium hyaluronate, sodium palmitoyl praline, stearoxytrimethylsilane, stearyl alcohol, sulfurized TEA- ricinoleate, talc, Thymus vulgaris, Tilia cordata, tocopherol, tocopheryl acetate, trideceth-9, triticum vulgare, tyrosine, undecylenoyl glycine, urea, Vaccinium myrtillus, valine, zinc oxide, zinc sulfate.

[0074] As described above, personal care products that may be formulated in accordance with the present disclosure include anti-dandruff products, anti-acne products, and products that prevent body odors. When formulating an anti- dandruff product, the product can comprise any suitable hair care product, such as a shampoo, conditioner, hair rinse, or the like.

[0075] Anti-dandruff haircare products can contain, in addition to the antimicrobial composition, water, emollients, surfactants, silicones, natural oils, humectants, panthenol, fragrance, and pH adjusters. Particularly suitable emollients used in conditioners include cetyl alcohol and stearyl alcohol. Particularly suitable surfactants used in conditioners include cationic surfactants such as cetrimonium chloride and behentrimonium chloride. Particularly suitable silicones used in conditioners include dimethicone and cyclomethicone. Particularly suitable natural oils used in conditioners include argan oil and coconut oil, and particularly suitable humectants used in conditions include glycerin. Particularly suitable pH adjusters used in conditioners include citric acid.

[0076] In another aspect, the hair care product is shampoo. The shampoo can contain the antimicrobial composition of the present disclosure, water, surfactants, cocamidopropyl betaine, cocamide DEA or cocamide MEA, conditioning agents, fragrance, citric acid, sodium chloride, glycerol distearate, a preservative, and natural extracts or oils. Particularly suitable surfactants used in shampoo include sodium lauryl sulfate and sodium laureth sulfate. Particularly suitable conditioning 19    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) agents used in shampoo include polyquaternium-10 and guar hydroxypropyltrimonium chloride. Particularly suitable natural extracts or oils used in shampoo include aloe vera and tea tree oil.

[0077] When formulating an anti-dandruff product, the product can contain one or more anti-dandruff antimicrobial compounds as described above in an amount of from about 0.0001% by weight to about 15% by weight. More particularly, one or more anti-dandruff antimicrobial compounds can be present in the product in an amount less than about 10% by weight, such as in an amount less than about 5% by weight, such as in an amount less than about 2% by weight, such as in an amount less than about 1.5% by weight, such as in an amount less than about 1% by weight, such as in an amount less than about 0.5% by weight. One or more alkylene glycol esters can be present in the product in an amount from about 0.01% by weight to about 18% by weight. For instance, one or more alkylene glycol esters can be present in the product in an amount less than about 15% by weight, such as in an amount less than about 10% by weight, such as in an amount less than about 5% by weight, such as in an amount less than about 3% by weight, such as in an amount less than about 2% by weight, and in an amount greater than about 0.1% by weight, such as in an amount greater than about 0.5% by weight, such as in an amount greater than about 1% by weight.

[0078] The present disclosure is also directed to incorporating the antimicrobial composition into an anti-acne product. Acne including acne vulgaris is a very common skin disorder. Acne vulgaris (cystic acne or simply acne) is characterized by areas of skin with seborrhea (scaly red skin), comedones (blackheads and whiteheads), papules (pinheads), pustules (pimples), nodules (large papules) and possibly scarring. Acne vulgaris affects mostly skin with the densest population of sebaceous follicles. These areas include the face, the upper part of the chest, and the back. Severe acne vulgaris is inflammatory, but acne vulgaris can also manifest in non-inflammatory forms.

[0079] The lesions are caused by changes in pilosebaceous units, skin structures consisting of a hair follicle and its associated sebaceous gland, changes that require androgen stimulation. Androgen metabolism plays an important role in the control of both sebum excretion and keratinization patterns in the 20    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) pilosebaceous unit. The enzyme 5-α-testosterone reductase is responsible for the conversion of testosterone to dihydrotestosterone (DHT), and DHT is thought to modulate both keratin formation and sebum production. Malfunctioning of the pilosebaceous unit is also the cause of other common skin disorders, such as seborrhea, dandruff, androgenic alopecia and hirsutism.

[0080] Acne is thought to be caused by the interplay of four factors. Excessive sebum production secondary to sebaceous gland hyperplasia is the first abnormality to occur. Subsequent hyperkeratinization of the hair follicle prevents normal shedding of the follicular keratinocytes, which then obstruct the follicle and form an inapparent microcomedo. Lipids and cellular debris soon accumulate within the blocked follicle. This microenvironment encourages colonization of Propionibacterium acnes (P. acnes, also referred to as Cutibacterium acnes), which provokes an immune response through the production of numerous inflammatory mediators. Inflammation is further enhanced by follicular rupture and subsequent leakage of lipids, bacteria, and fatty acids into dermis.

[0081] In addition to the antimicrobial composition of the present disclosure, the anti-acne product can contain various other components and ingredients. For instance, the product can contain an exfoliant which can help to remove dead skin cells that can clog pores. One example of an exfoliant is lactic acid. The composition can also contain an anti-inflammatory agent which reduces inflammation and redness associated with acne. Anti-inflammatory agents include niacinamide, aloe vera, and chamomile.

[0082] Anti-acne products can also contain sebum regulators which control excess oil production. Sebum regulators include retinoids, such as adapalene and tretinlin, or sulfur.

[0083] The anti-acne product can also contain moisturizers and skin soothing agents. Moisturizers include hyaluronic acid and glycerin. Skin soothing agents include allantoin, green tea extract, and licorice root extract. Astringents can also be present in the product including witch hazel and alcohol.

[0084] Anti-acne products can also contain antioxidants such as vitamin C and vitamin E. Further, hydrators can also be present in the product. Hydrators include hyaluronic acid and ceramides. 21    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00)

[0085] When formulating an anti-acne product, the product can contain one or more anti-acne antimicrobial compounds as described above in an amount of from about 0.0001% by weight to about 20% by weight. More particularly, one or more anti-acne antimicrobial compounds can be present in the product in an amount less than about 10% by weight, such as in an amount less than about 5% by weight, such as in an amount less than about 2% by weight, such as in an amount less than about 1.5% by weight, such as in an amount less than about 1% by weight, such as in an amount less than about 0.5% by weight. One or more alkylene glycol esters can be present in the product in an amount from about 0.01% by weight to about 18% by weight. For instance, one or more alkylene glycol esters can be present in the product in an amount less than about 15% by weight, such as in an amount less than about 10% by weight, such as in an amount less than about 5% by weight, such as in an amount less than about 3% by weight, such as in an amount less than about 2% by weight, and in an amount greater than about 0.1% by weight, such as in an amount greater than about 0.5% by weight, such as in an amount greater than about 1% by weight.

[0086] In still another aspect, the present disclosure is directed to a product for preventing malodors, such as body odor, containing the antimicrobial composition of the present disclosure. Body odor, for instance, is typically caused by microorganisms.

[0087] Secretions from the apocrine sweat glands, which are primarily located in the human underarm, are largely odorless. The human underarm is consistently warm, and sweat glands present in the underarm provide moisture, which when excreted, has a vital cooling effect. When adult underarms are washed with alkaline pH soap, the skin loses its acid mantle (pH 4.5-6), raising the skin pH and disrupting the skin barrier. Many bacteria thrive at this elevated pH, making the skin susceptible to bacterial colonization. The bacteria feed on the secretions from the apocrine glands, and on dead skin and hair cells, which results in the degradation of long-chain fatty acids into shorter chain acids such as formic acid or butyric acid, which are the primary cause of body odor.

[0088] Deodorants function in many ways to eliminate odor. For example, they are able to mask or complement the odor to minimize the offensive smell; trap the 22    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) odor so that the volatile components do not reach the nose; or prevent or slow down the generation of volatile odiferous chemicals. Odor preventing products made according to the present disclosure further contain one or more antimicrobial compounds that slow bacterial growth for preventing the odors from occurring.

[0089] Deodorant products formulated in accordance with the present disclosure can come in different forms. For instance, the deodorant product can be an aerosol spray, a roll-on, a deodorant stick, a pump, a powder, a powder spray, a cream, or a gel.

[0090] Although the ingredients in deodorant products can vary depending on whether the product is a stick product, a roll-on product, a gel product, a cream product, or a spray product, many of the ingredients remain consistent among all of the deodorant product formulations.

[0091] The deodorant product, for instance, can contain the antimicrobial composition of the present disclosure, antiperspirant active ingredients, odor- fighting ingredients, emollients, moisturizers, thickeners, stabilizers, skin conditioners, antibacterial agents, solvents, and propellants. Particularly suitable antiperspirant active ingredients used in deodorant products include aluminum compounds such as aluminum chlorohydrate and aluminum tetrachlorohydrex glycine. Particularly suitable odor-fighting ingredients used in deodorant products include fragrance, sodium bicarbonate, and zinc compounds such as zinc ricinoleate. Particularly suitable emollients and moisturizers used in deodorant products include glycerin, shea butter, cocoa butter, and jojoba oil. Particularly suitable skin conditioners used in deodorant products include aloe vera and Vitamin E (e.g., tocopheryl acetate). Particularly suitable antibacterial agents used in deodorant products include triclosan and particularly suitable solvents used in deodorant products include propylene glycol. Particularly suitable emollients and moisturizers used in deodorant products includes glycerin, shea butter, cocoa butter, and jojoba oil.

[0092] The present disclosure may be better understood with reference to the following examples. 23    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) Example No.1 Methods

[0093] To demonstrate the synergistic effect in the examples below, Propylene glycol caprylate (PGC) and ethylene glycol caprylate (EGC) is used. The propylene glycol caprylate (PGC) used is a mixture of propylene glycol monocaprylates (octanoic acid-2-hydroxy-1-methylethyl ester and 2-hydroxylpropyl caprylate) and propylene glycol dicaprylate (1,2-propylene glycol dicaprylate), the mixture comprising about 70-80 wt.-% of the propylene glycol monocaprylates and about 20-30 wt.-% of the propylene glycol dicaprylate. The Ethylene glycol caprylate (EGC) used is a mixture of Ethylene glycol monocaprylate and Ethylene glycol dicaprylate, the mixture comprising about 70-80 wt.-% of the Ethylene glycol monocaprylate and about 20-30 wt.-% of the Ethylene glycol dicaprylate. Test procedure

[0094] The synergistic activity of alkylene glycol esters and antimicrobial compounds are demonstrated as part of two-component compositions.

[0095] A wide range of concentrations were tested against: S. epidermidis, C. minutissimum, and M. luteus.

[0096] The lowest concentration of each mixture or single compound which prevents an observable level of growth was determined to be the minimum inhibitory concentration (MIC) value. The MIC value was determined for each microorganism.

[0097] Serial dilutions of each mixture or single compound were prepared. Micro-organisms were inoculated into appropriate liquid media: The final concentrations of micro-organisms in media was approximately 104-105CFU / ml. The inoculated media was introduced to each of the serial dilutions at a 1:1 ratio, and incubated at 35±2°C for 24-48 hours.

[0098] The MICs for each mixture was compared with the MIC of each single compound alone.

[0099] Synergy was determined using the Kull equation (F.C. Kull et. al., “Mixtures of Quaternary Ammonium Compounds and Long-chain Fatty Acids as 24    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) Antifungal Agents”, Appl Microbiol.1961 Nov; 9(6): 538–541), which calculates a Synergy Index (SI) according the following equation: SI = Qa / QA + Qb / QB wherein QA= concentration of compound A in ppm, acting alone produced an end point, Qa = concentration of compound A in ppm, in the mixture, which produced an end point, QB = concentration of compound B in ppm, acting alone produced an end point, Qb = concentration of compound B in ppm, in the mixture, which produced an end point

[0100] In this study the end point is measured by the MIC.

[0101] Synergy is demonstrated by an SI value of less than 1. An additive effect is demonstrated by an SI value of equal to 1. Antagonism is demonstrated by an SI value of greater than 1. Synergy index:

[0102] The antimicrobial compounds tested in this example included farnesol, geraniol, benzyl alcohol, phenoxyethanol, caprylyl glycol, ethylhexyl glycerin, potassium sorbate, zinc neodecanoate, zinc oxide, sodium salicylate, azelaic acid, benzoyl peroxide and hydroxyacetophenone. 25    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) Synergy observed Aggregate of ratio Antimicrobial range – Synergy Aggregate of ratio i i i l

[0103] The combination of the alkylene glycol esters and farnesol displayed synergy against S. epidermidis, C. minutissimum, and M. luteus. 26    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00)

[0104] The combination of the alkylene glycol esters and geraniol displayed synergy against S. epidermidis, C. minutissimum, and M. luteus.

[0105] The combination of the alkylene glycol esters and benzyl alcohol displayed synergy against S. epidermidis, C. minutissimum, and M. luteus.

[0106] The combination of the alkylene glycol esters and caprylyl glycol displayed synergy against S. epidermidis, C. minutissimum, and M. luteus.

[0107] The combination of the alkylene glycol esters and phenoxyethanol displayed synergy against S. epidermidis.

[0108] The combination of the alkylene glycol esters and ethylhexylglycerin displayed synergy against S. epidermidis, C. minutissimum, and M. luteus.

[0109] The combination of the alkylene glycol esters and potassium sorbate displayed synergy against M. luteus.

[0110] The combination of the alkylene glycol esters and zinc neodecanoate displayed synergy against S. epidermidis.

[0111] The combination of the alkylene glycol esters and zinc oxide displayed synergy against M. luteus.

[0112] The combination of the alkylene glycol esters and sodium salicylate displayed synergy against S. epidermidis.

[0113] The combination of the alkylene glycol esters and azelaic acid displayed synergy against S. epidermidis.

[0114] The combination of the alkylene glycol esters and benzoyl peroxide displayed synergy against S. epidermidis.

[0115] The combination of the alkylene glycol esters and hydroxyacetophenone displayed synergy against S. epidermidis.

[0116] Synergy against S. epidermidis Active weight ratio ofMIC (ppm to inhibit growth)  SynergyPGCF lP F l i d Active weight ratio ofMIC (ppm to inhibit growth)  Synergy     Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) PGC alone  3125     10:1  1563  156  0.75    yPGC:Benzyl Alcohol PGC  Benzyl Alcohol  index  Active weight ratio of MIC (ppm) to inhibit growth Synergy EGC: Benzyl Alcohol EGC Benzyl Alcohol index Active weight ratio ofMIC (ppm to inhibit growth)  SynergyPGC:Caprylyl GlycolPGC Caprylyl Glycol index Active weight ratio of MIC (ppm to inhibit growth) Synergy Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) 1:10 250 2500 0.63 Caprylyl Glycol alone 5000   yPGC:Phenoxyethanol PGC  Phenoxyethanol  index  gpp g   y gyPGC:Ethylhexyl glycerin PGC  Ethylhexylglycerin  index  Active weight ratio of MIC (ppm to inhibit growth) Synergy EGC: Ethylhexyl Glycerin EGC Ethylhexyl Glycerin index Active weight ratio of MIC (ppm to inhibit growth) Synergy PGC:Zinc NeodecanoatePGC Zinc Neodecanoateindex Active weight ratio of MIC (ppm) to inhibit growth Synergy E di li l t i li l i d Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) 1:16 313 5000 0.50 1:8 313 2500 0.38 Actve weg t rato o MIC (ppm) to n bt growt Synergy EGC: Azelaic Acid EGC Azelaic Acid index Active weight ratio of MIC (ppm) to inhibit growth Synergy EGC: Benzoyl Peroxide EGC Benzyl Peroxide index Active weight ratio of MIC (ppm) to inhibit growth Synergy i Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) 4:1 625 156 0.56 8:1 625 78 0.53

[0117] Synergy against C. minutissimum Active weight ratio ofMIC (ppm to inhibit growth)SynergyPGC:Farnesol PGC Farnesol index Active weight ratio ofMIC (ppm to inhibit growth)SynergyP i l P i l i d Active weight ratio ofMIC (ppm to inhibit growth)Synergy     Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) 1:3 391 1250 0.75 Benzyl Alcohol alone 5000 yPGC:Caprylyl Glycol PGC Caprylyl Glycol index Actve weg t rato oppm o n growSynergyPGC:Ethylhexyl glycerin PGC Ethylhexyl glycerin index

[0118] Synergy against M. luteus Active weight ratio ofMIC (ppm to inhibit growth)SynergyPGC:Farnesol PGC Farnesol index Active weight ratio ofMIC (ppm to inhibit growth)Synergyi l i l i 32    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) Active weight ratio ofMIC (ppm to inhibit growth)SynergyPGC:Benzyl Alcohol PGC Benzyl Alcohol index gy gyPGC:Caprylyl Glycol PGC Caprylyl Glycol index Active weight ratio ofMIC (ppm to n bt growt )SynergyPGC:Ethylhexyl glycerin PGC Ethylhexyl glycerin index Active weight ratio ofMIC (ppm to inhibit growth)SynergyPGC:Potassium Sorbate PGC Potassium Sorbate index Active weight ratio ofMIC (ppm to inhibit growth)SynergyP Zi id P Zi id i d Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) Example No.2

[0119] In this example, a challenge test was conducted in order to demonstrate synergy that occurs when alkylene glycol esters are combined with antimicrobial compounds and tested against dandruff-causing microorganisms or acne- associated organisms.

[0120] In order to quantify synergy, 48-hour challenge testing was conducted as against Malassezia furfur, which is known to cause dandruff and Cutibacterium acnes, which is associated with acne. M. furfur was tested against salicylic acid, zinc pyrithione (“ZPT”), climbazole, and piroctone olamine. C. acnes was tested against salicylic acid. M. furfur and C. acnes were tested against the antimicrobial compound alone, against either alkylene glycol ester, propylene glycol caprylate (“PGC”) and / or ethylene glycol caprylate (“EGC”), and against a blend of the antimicrobial compound and alkylene glycol ester to determine the synergy index of the blend.

[0121] In this study the end point is measured by recovery in CFU / ml, which is then normalised to Relative Colony Count (RCC). To calculate Relative Colony Count (RCC), The log CFU / ml recovery at the given timepoint is divided by the log CFU / ml of the initial inoculum.

[0122] The Synergy indices (SI) for binary combinations of substances A and B are calculated according to Kull’s equation: SI = (RCCM x PA) / RCCA + (RCCM x PB) / RCCB where: RCCA is the RCC value for substance A, RCCB is the RCC value for substance B, RCCM is the RCC value for the mixture of A and B, PA is the proportion of A in the mixture, PB is the proportion of B in the mixture. A SI equal to or greater than 1 means that no synergy is present.

[0123] The following results were obtained: 34    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) Synergy observed Aggregate of ratio Antimicrobial range – Synergy Aggregate of ratio Antimicrobial observed ran e –

[0124] Malassezia furfur:

[0125] Synergy with propylene glycol caprylate Active Conc Active weight ratio Relative colony count (Time) (ppm) of PGC: active 4 Hours 24 Hours 48 Hours 35    Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) Active Conc Active weight ratio Relative colony count (Time) (ppm) of PGC: active 4 Hours 24 Hours 48 Hours ZPT 5000 100 094 (ppm) of PGC: active 4 Hours 24 Hours 48 Hours c ve onc c ve weg ra o ea ve coony coun ( me) (ppm) of PGC: active 4 Hours 24 Hours 48 Hours Active Conc Active weight ratio Relative colony count (Time) (ppm) of PGC: active 4 Hours 24 Hours 48 Hours Active Conc Active weight ratio Relative colony count (Time) (ppm) of PGC: active 4 H r 24 H r 48 H rs Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) Active Conc Active weight ratio Relative colony count (Time) (ppm) of PGC: active 4 Hours 24 Hours 48 Hours Pi t l i 10000 077 (ppm) of PGC: active 4 Hours 24 Hours 48 Hours y egy ye e gyco cap yae Active Conc Active weight ratio Relative colony count (Time) (ppm) of EGC: active 24 Hours Active Conc Active weight ratio Relative colony count (Time) (ppm) of EGC: active 24 Hours Active Conc Active weight ratio Relative colony count (Time) (ppm) of EGC: active 24 H Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) Active Conc Active weight ratio Relative colony count (Time) (ppm) of EGC: active 24 Hours Pi t l i 10000 073 e) (ppm) of EGC: active 24 Hours c ve onc c ve weg ra o ea ve coony coun ( me) (ppm) of EGC: active 24 Hours Active Conc Active weight ratio Relative colony count (Time) (ppm) of EGC: active 24 Hours Active Conc Active weight ratio Relative colony count (Time) (ppm) of EGC: active 24 H r Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) Active Conc Active weight ratio Relative colony count (Time) (ppm) of EGC: active 24 Hours ZPT 10000 05 e) (ppm) of EGC: active 24 Hours c ve onc c ve weg ra o ea ve coony coun ( me) (ppm) of EGC: active 24 Hours Active Conc Active weight ratio Relative colony count (Time) (ppm) of EGC: active 24 Hours Active Conc Active weight ratio Relative colony count (Time) (ppm) of EGC: active 24 H r Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) Active Conc Active weight ratio Relative colony count (Time) (ppm) of EGC: active 24 Hours ZPT 10000 05

[0128] Synergy with propylene glycol caprylate Active Conc Active weight ratio Relative colony count (Time) (ppm) of PGC: active 24 Hours

[0009] s s own above, e presence o e a yene gyco esers drama ca y improved the efficacy of the antimicrobial compounds.

[0130] These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only and is not intended to limit the invention so further described in such appended claims. 40

Claims

Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) What Is Claimed:

1. Antimicrobial composition for producing a biocidal or biostatic effect on microorganisms on a skin or a scalp of a user, the antimicrobial composition having anti-dandruff, anti-malodor, and / or anti-acne properties, the antimicrobial composition comprising at least one antimicrobial compound in combination with an alkylene glycol ester, the at least one antimicrobial compound being configured to produce a biocidal or biostatic effect against at least one microorganism that causes dandruff, body odor, and / or acne.

2. The antimicrobial composition according to claim 1, wherein the composition is formulated for anti-dandruff activity and the at least one antimicrobial compound contained in the composition comprises piroctone olamine, zinc pyrithione, salicylic acid and salts thereof, climbazole, ketaconazole, hydroxyacetophenone, selenium sulphide, coal tar, or mixtures thereof.

3. The antimicrobial composition according to claim 1 or 2, wherein the composition is formulated in order to produce a biocidal or biostatic effect against the growth of microorganisms associated with dandruff including Malassezia Spp. such as Malassezia globosa, Malassezia furfur, MalasseziaMalassezia pachydermatis and / or Malassezia restricta.

4. The antimicrobial composition according to claim 1, wherein the composition is formulated to treat acne and the at least one antimicrobial compound contained in the composition comprises salicylic acid and salts thereof, dehydroacetic acid and salts thereof, benzoyl peroxide, glycolic acid and salts thereof, azelaic acid and salts thereof, hydroxyacetophenone, gluconolactone, niacinamide, or mixtures thereof.

5. The antimicrobial composition according to claim 1 or 4, wherein the composition is formulated in order to produce a biocidal or biostatic effect against the growth of microorganisms associated with acne including Cutibacterium acnes, Staphylococcus epidermidis, and / or Propionibacterium acnes.

6. The antimicrobial composition according to claim 1, wherein the composition is formulated to prevent body odor and the at least one antimicrobial compound contained in the composition comprises zinc oxide, zinc citrate, zinc pyrrolidone carboxylic acid (zinc PCA), zinc glycinate, aluminum sulphate, 41   Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) aluminum zirconium, aluminum chloride, aluminum chlorohydrate, other aluminum salts, benzyl alcohol, phenoxyethanol, ethylhexyl glycerin, farnesol, geraniol, caprylyl glycol, octenidine dihydrochloride, or mixtures thereof.

7. The antimicrobial composition according to claim 1 or 6, wherein the composition is formulated in order to produce a biocidal or biostatic effect against the growth of microorganisms associated with body odor including Corynebacterium striatum, Corynebacterium jeikeium, Corynebacterium xerosis, Staphylococcus hominis, Staphylococcus epidermidis, and / or Micrococcus luteus.

8. The antimicrobial composition according to any of the preceding claims, wherein said alkylene glycol ester and said antimicrobial compound are present in a synergistically effective amount.

9. The antimicrobial composition according to claim 1, wherein said alkylene glycol ester comprises propylene glycol ester, preferably propylene glycol caprylate, and in particular propylene glycol monocaprylate.

10. The antimicrobial composition according to claim 1, wherein said alkylene glycol ester comprises ethylene glycol ester, preferably ethylene glycol caprylate, and in particular ethylene glycol monocaprylate.

11. The antimicrobial composition according to claim 1, wherein said alkylene glycol ester comprises alkylene glycol monoester, alkylene glycol diester, or mixtures thereof, preferably comprising propylene glycol monoester, propylene glycol diester, or mixtures thereof, more preferably comprising propylene glycol monocaprylate, propylene glycol dicaprylate, or mixtures thereof, and in particular a mixture of propylene glycol monocaprylate and propylene glycol dicaprylate or propylene glycol monocaprylate.

12. The antimicrobial composition according to claim 1, wherein said alkylene glycol ester comprises alkylene glycol monoester, alkylene glycol diester, or mixtures thereof, preferably comprising ethylene glycol monoester, ethylene glycol diester, or mixtures thereof, more preferably comprising ethylene glycol monocaprylate, ethylene glycol dicaprylate, or mixtures thereof, and in particular a mixture of ethylene glycol monocaprylate and ethylene glycol dicaprylate or ethylene glycol monocaprylate. 42   Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) 13. The antimicrobial composition according to claim 1, wherein said alkylene glycol ester is a mixture of propylene glycol monocaprylate and propylene glycol dicaprylate comprising at least 10 wt.-%, preferably at least 30 wt.-%, and in particular at least 60 wt.-%, of the propylene glycol monocaprylate, based on the weight sum of propylene glycol monocaprylate and propylene glycol dicaprylate.

14. The antimicrobial composition according to any of the preceding claims, wherein said alkylene glycol ester and said antimicrobial compound are present in a weight ratio of about 1:1000 to about 2500:1, or about 1:1000 to about 2000:1, or about 1:1000 to about 1500:1, or about 1:1000 to about 500:1, or about 1:1000 to about 50:1, or about 1:800 to about 200:1, or about 1:800 to about 40:1, or about 1:600 to about 50:1, or about 1:600 to about 30:1, or about 1:550 to about 100:1, or about 1:550 to about 20:1, or about 1:250 to about 15:1, or about 1:100 to about 10:

1.

15. A personal care product for topical application to a user’s skin or scalp, comprising an antimicrobial composition according to any one of claims 1 to 14.

16. The personal care product according to claim 15, wherein the antimicrobial composition is present in the personal care product in an amount of from about 0.0005% by weight to about 10% by weight based on the total weight of the personal care product.

17. The personal care product according to claim 15 or 16, wherein the personal care product comprises an anti-dandruff personal care product, an anti- acne personal care product, or a deodorant.

18. A method for producing a biocidal or biostatic effect on microorganisms on a skin or a scalp of a user comprising: applying to a skin or a scalp of a user an antimicrobial composition comprising an alkylene glycol ester and at least one antimicrobial compound comprising piroctone olamine, zinc pyrithione, salicylic acid and salts thereof, gluconolactone, ethylhexyl glycerin, climbazole, caprylyl glycol, hydroxyacteophenone, azelaic acid, zinc oxide, zinc citrate, zinc pyrrolidone carboxylic acid (zinc PCA), zinc glycinate, niacinamide, benzoyl peroxide, ketaconazole, selenium sulphide, coal tar, dehydroacetic acid and salts thereof, 43   Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) glycolic acid and salts thereof, benzyl alcohol, phenoxyethanol, farnesol, hydroxyacetophenone, geraniol, octenidine dihydrochloride, or mixtures thereof.

19. The method according to claim 18, wherein the antimicrobial composition comprises an anti-dandruff composition and wherein the at least one antimicrobial compound comprises piroctone olamine, zinc pyrithione, salicylic acid and salts thereof, climbazole, ketaconazole, hydroxyacetophenone, selenium sulphide, coal tar, or mixtures thereof and wherein the antimicrobial composition is applied to a scalp of a user.

20. The method according to claim 18, wherein the antimicrobial composition comprises an anti-acne composition and wherein the at least one antimicrobial compound comprises salicylic acid and salts thereof, dehydroacetic acid and salts thereof, benzoyl peroxide, glycolic acid and salts thereof, azelaic acid and salts thereof, hydroxyacetophenone, gluconolactone, niacinamide, or mixtures thereof.

21. The method according to claim 18, wherein the antimicrobial composition comprises an anti-malodor composition and wherein the at least one antimicrobial compound comprises zinc oxide, zinc citrate, zinc pyrrolidone carboxylic acid (zinc PCA), zinc glycinate, other zinc salts, benzyl alcohol, phenoxyethanol, ethylhexyl glycerin, farnesol, geraniol, caprylyl glycol, octenidine dihydrochloride, or mixtures thereof.

22. The method according to claim 21, wherein the antimicrobial composition is applied to the underarms of a user.

23. The method according to claim 21, wherein the antimicrobial composition is contained in a deodorant.

24. The method according to any of claims 18 to 23, wherein the alkylene glycol ester increases the efficacy of the at least one antimicrobial compound against a microorganism found on the skin or on the scalp.

25. The method according to claim 24, wherein the microorganism comprises M. furfur.

26. The method according to claim 24, wherein the microorganism comprises C. acnes. 44   Attorney Docket No.: ARXPC-336-PCT (LP3741PC00) 27. The method according to claim 24, wherein the microorganism comprises M. luteus, C. minutissimum, and / or S. epidermidis.

28. The method according to any of claims 18 to 27, wherein said alkylene glycol ester comprises propylene glycol ester, preferably propylene glycol caprylate, and in particular propylene glycol monocaprylate.

29. The method according to any of claims 18 to 27, wherein said alkylene glycol ester comprises ethylene glycol ester, preferably ethylene glycol caprylate, and in particular ethylene glycol monocaprylate.

30. The method according to claim 28, wherein said alkylene glycol ester comprises alkylene glycol monoester, alkylene glycol diester, or mixtures thereof, preferably comprising propylene glycol monoester, propylene glycol diester, or mixtures thereof, more preferably comprising propylene glycol monocaprylate, propylene glycol dicaprylate, or mixtures thereof, and in particular a mixture of propylene glycol monocaprylate and propylene glycol dicaprylate or propylene glycol monocaprylate.

31. The method according to claim 29, wherein said alkylene glycol ester comprises alkylene glycol monoester, alkylene glycol diester, or mixtures thereof, preferably comprising propylene glycol monoester, propylene glycol diester, or mixtures thereof, more preferably comprising ethylene glycol monocaprylate, ethylene glycol dicaprylate, or mixtures thereof, and in particular a mixture of ethylene glycol monocaprylate and ethylene glycol dicaprylate or ethylene glycol monocaprylate.

32. The method according to any of claims 18 to 28, wherein said alkylene glycol ester and said antimicrobial compound are present in a weight ratio of about 1:1000 to about 2500:1, or about 1:1000 to about 2000:1, or about 1:1000 to about 1500:1, or about 1:1000 to about 500:1, or about 1:1000 to about 50:1, or about 1:800 to about 200:1, or about 1:800 to about 40:1, or about 1:600 to about 50:1, or about 1:600 to about 30:1, or about 1:550 to about 100:1, or about 1:550 to about 20:1, or about 1:250 to about 15:1, or about 1:100 to about 10:

1. 45

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