EP4608139A1 - Antimicrobial compositions - Google Patents

Abstract

Antimicrobial compositions and related methods are disclosed. The antimicrobial compositions include salicylic, glycolic acid, and at least one anionic surfactant comprising an alkyl sulfate. The antimicrobial compositions exhibiting yeasticidal efficacy when applied to bovine teats.

Description

ANTIMICROBIAL COMPOSITIONS

BACKGROUND

1. Field of the Invention

[0001 ] The present invention pertains to antimicrobial compositions. More particularly, the present invention is directed toward antimicrobial compositions that possess yeasticidal functionality.

2. Description of the Related Art

[0002] Antimicrobial agents are generally used to kill pathogenic microorganisms that create a risk of infection for humans or animals. Antimicrobial agents are used especially in veterinary applications to control and/or prevent hoof diseases, mastitis, or topical infections. Prevention of mastitis is a major goal of the dairy industry, where the disease may result from the contact of the bovine or ovine mammary gland with pathogenic microorganisms. Mastitis is a potentially serious infection, where severe cases can cause the death of a dairy animal.

[0003] To reduce mastitis, commercial teat dips have been developed that are generally administered to the animal’s teat by dipping, spraying, or foaming the teat prior to and after milking. A number of teat disinfectant compositions exist that are effective in killing various mastitis-causing bacteria. However, regulatory changes in certain jurisdictions now require that, in addition to killing bacteria, teat disinfectants possess yeasticidal functionality and must be effective pre-milking at short contact times. Traditional oxidative germicides employing iodine and chlorine dioxide as the primary antimicrobial agents exhibit yeasticidal functionality. However, these compositions are not desirable in some markets because of residue concerns for iodine and chlorate. Teat dip compositions that comprise less concerning active ingredients from a milk quality perspective, such as those comprising one or more organic acids as the antimicrobial active(s) do not exhibit yeasticidal efficacy.

[0004] The effect of antimicrobial compositions on animal skin health is also a concern. Certain antimicrobial compositions have been developed that offer broad spectrum in vitro protection against a number of mastitis-causing pathogens. However, these same antimicrobial compositions can cause undesirable irritation of the animal’s skin making the compositions ill suited for in vivo use.

[0005] Therefore, there is a need for antimicrobial compositions that offer protection against a broad spectrum of microbes, including yeasts, are effective at short contact times, and are non-irritating to the skin.

SUMMARY

[0006] In one embodiment of the present invention there is provided an antimicrobial composition that includes salicylic acid, glycolic acid, and at least one anionic surfactant.

[0007] In another embodiment of the present invention there is provided an antimicrobial composition that comprises salicylic acid, glycolic acid, and at least one alkyl sulfate surfactant. In preferred embodiments, the composition comprises at least one alkyl sulfate surfactant comprising sodium lauryl sulfate.

[0008] In yet another embodiment of the present invention there is provided an antimicrobial composition that comprises salicylic acid, glycolic acid, and at least one anionic surfactant comprising an alkyl sulfate. In such embodiment, the antimicrobial composition exhibits at least a four-log reduction in C. albicans when tested in accordance with EN 1657 at a one-minute contact time, at 30°C, and in the presence of 10 g/L bovine albumin and 10 g/L yeast extract as an interfering substance (high soil condition), or with 3 g/L bovine albumin as interfering substance (low soil condition).

[0009] According to still another embodiment of the present invention there is provided an antimicrobial composition that comprises salicylic acid, glycolic acid, at least one anionic surfactant comprising an alkyl sulfate, and optionally one or more of the following components: a freezing point depressant compound, magnesium oxide, at least one additional anionic surfactant selected from the group consisting of a-olefin sulfonates and alkyl sulfonates, and at least one non-ionic surfactant comprising an alcohol ethoxylate.

[0010] According to a further embodiment of the present invention there is provided an antimicrobial composition that comprises salicylic acid, glycolic acid, and at least one anionic surfactant. In such embodiment, the composition is storage stable for at least one month at 4°C.

[0011 ] According to still another embodiment of the present invention there is provided an antimicrobial composition that comprises from 0.15% to 0.6% by weight of salicylic acid, from 0.5% to 10% by weight of glycolic acid, from 0.3% to 1 % of at least one anionic surfactant, and optionally from 0.5% to 10% of a freezing point depressant compound and/or from 0.02% to 1 % of magnesium oxide.

[0012] In another embodiment of the present invention there is provided a method for controlling or preventing bovine mastitis. The method includes contacting the teats of a cow with a teat dip, which includes salicylic acid, glycolic acid, and an anionic surfactant, preferably an alkyl sulfate surfactant, and even more preferably sodium lauryl sulfate.

[0013] According to another embodiment of the present invention there is provided a method for controlling or preventing bovine mastitis comprising contacting the teats of a cow with a teat dip comprising an antimicrobial composition as described herein.

[0014] According to still a further embodiment of the present invention there is provided an antimicrobial teat dip composition for use in the control or prevention of bovine mastitis when contacted with the teats of a cow. The composition comprises salicylic acid, glycolic acid, and at least one anionic surfactant. Preferably, the antimicrobial composition exhibits at least a four-log reduction in C. albicans when tested in accordance with EN 1657 at a one-minute contact time, at 30°C, and in the presence of 10 g/L bovine albumin and 10 g/L yeast extract as an interfering substance (high soil condition), or with 3 g/L bovine albumin as interfering substance (low soil condition).

[0015] According to yet another embodiment of the present invention there is provided an antimicrobial teat dip composition for use in the control or prevention of bovine mastitis when contacted with the teats of a cow, wherein the composition comprises an antimicrobial composition as described herein. DETAILED DESCRIPTION

[0016] Various embodiments of the present invention concern antimicrobial compositions, that exhibit fungicidal efficacy, that include salicylic acid, glycolic acid, and one or more anionic surfactants.

[0017] In certain embodiments, salicylic acid and glycolic acid are the only organic acids present in the compositions. However, this need not always be the case, as certain other organic acids that possess antimicrobial characteristics may also be included such as lactic acid, tartaric acid, citric acid, ascorbic acid, maleic acid, succinic acid, mandelic acid, dodecylbenzenesulfonic acid, propionic acid, gluconic acid, malic acid, benzoic acid, aspartic acid, acetic acid, oxalic acid, glutamic acid, adipic acid, hexanoic acid, octanoic acid, nonanoic acid, decanoic acid, and undecanoic acid. Preferably, though, in the embodiments of the present invention in which other organic acids are present, salicylic acid and glycolic acid make up the majority of all organic acids present in the composition. In certain other embodiments, inorganic acids having pK_a characteristics approximating those of organic acids may also be used, such as, sulfamic acid.

[0018] Anionic surfactants suitable for use in the present invention include, but are not limited to, alkyl sulfonates, secondary alkane sulfonates, alkyl sulfates, alkyl ether sulfates, aryl sulfonates, aryl sulfates, alkylaryl sulfonates, alkylaryl sulfates and alkyl ether sulfonates, and the corresponding acids thereof. A non-limiting list of specific anionic surfactants suitable for use in the present invention includes alkali lauryl sulfates, e.g., sodium lauryl sulfate (SLS), alkali dodecylbenzenesulfonates, alkali octane sulfonates, e.g., sodium octane sulfonate (SOS), alkali secondary alkane sulfonates, alkali lauryl ether sulfates and ammonium salts thereof. Additional anionic surfactants may include: a linear alkyl benzene sulfonate, an alkyl a-sulfomethyl ester, an a-olefin sulfonate, an alcohol ether sulfate, an alkylsulfo succinate, and a dialkylsulfo succinate. Specific examples of such additional anionic surfactants are linear C10-C16 alkylbenzene sulfonic acid, linear C10-C16 alkylbenzene sulfonate or alkali metal, alkaline earth metal, amine and ammonium salts thereof, e.g., sodium dodecylbenzene sulfonate, sodium C14- C a-olefin sulfonate, sodium methyl a-sulfomethyl ester and disodium methyl a-sulfo fatty acid salts. In certain embodiments, the antimicrobial compositions of the present invention may include a mixture of any of the above listed anionic surfactants. It is within the scope of the present invention that all anionic surfactants disclosed hereto may be in acid form, or in the form of an alkali metal, an alkaline earth metal, an amine, or an ammonium salt. In certain embodiments, it is preferable that compositions according to the present invention do not comprise an a-olefin sulfonate as the only anionic surfactant. In other embodiments when SLS comprises an anionic surfactant, it is preferable that it be used in conjunction with a further surfactant, such as another anionic surfactant, a nonionic surfactant as discussed below, or both another anionic surfactant and a nonionic surfactant. In one or more embodiments, a combination of at least two, and preferably three, anionic surfactants are used. In particular, these preferred compositions comprise at least two of sodium a-olefin sulfonate, sodium alkane sulfonate, and sodium lauryl sulfate. In certain embodiments, the sodium alkane sulfonate is the predominant anionic surfactant followed by sodium lauryl sulfate and then sodium a-olefin sulfonate; however, this need not always be the case. In certain embodiments the weight ratio of sodium alkane sulfonate to sodium a-olefin sulfonate is from 2:1 to 4:1 , and preferably about 3:1. In certain embodiments, the weight ratio of sodium alkane sulfonate to sodium lauryl sulfate is 1.1 :1 to 3:1 , and preferably about 1.5:1. In certain embodiments, the weight ratio of sodium a-olefin sulfonate to sodium lauryl sulfate is 1 :1 to 1 :3, and preferably about 1 :2.

[0019] As indicated above, compositions according to the present invention may optionally, but preferably, comprise one or more nonionic surfactants. Nonionic surfactants suitable for use in the present invention include, but are not limited to, alkyl polyglucosides, alkyl ethoxylated alcohols, alkyl propoxylated alcohols, ethoxylated- propoxylated alcohols, sorbitans, sorbitan esters, alkanol amides, ethyleneoxidepropyleneoxide block copolymers, and mixtures thereof. A non-limiting list of specific nonionic surfactants includes a C9-C11 alcohol with an average of approximately 8 moles of ethylene oxide per mole of alcohol (Neodol® 91 -8 from Shell Chemicals), a Cs-C-is alcohol with odd or even number carbon chain, with an average of 6 to 18 moles of ethylene oxide per mole of alcohol, alkyl polyglucosides (e.g., Triton™ BG10 from Dow Corp, or Lutensol® GD 70 from BASF Corp.), branched secondary alcohol ethoxylates (e.g., TERGITOL™ TMN Series from Dow Corp.), ethylene oxide / propylene oxide copolymers (e.g., TERGITOL™ L Series from Dow Corp.), secondary alcohol ethoxylates (e.g., ECOSURF™ LF-20 or TERGITOL™ 15-S Series from Dow Corp.), polyether polyols (e.g., TERGITOL™ L-61 from Dow. Corp), nonylphenol ethoxylates (e.g., TERGITOL™ NP Series from Dow Corp.), octylphenol ethoxylates (e.g., TRITON™ X Series from Dow Corp), seed oil surfactants (e.g., ECOSURF™ SA surfactants from Dow Corp.), alkyl polysaccharides (e.g., ALKADET® series from Huntsman Chemicals), alkylamine ethoxylates (e.g., SURFONIC® T series from Huntsman Chemicals), amine oxides (e.g., EMPIGEN® 0 series from Huntsman Chemicals), block copolymers (e.g., EMPILAN® KCMP series from Huntsman Chemicals), castor oil ethoxylates (e.g., SURFONIC® CO series from Huntsman Chemicals), ceto-oleyl alcohol ethoxylates (e.g., EMPILAN® KLA series from Huntsman Chemicals), ceto-stearyl alcohol ethoxylates (e.g., EMPILAN® KM series from Huntsman Chemicals), decyl alcohol ethoxylates, dinonyl phenol ethoxylates (e.g., SURFONIC® DNP series from Huntsman Chemicals), Dodecyl phenol ethoxylates (e.g., SURFONIC® DDP series from Huntsman Chemicals), end-capped ethoxylates (e.g., TERIC® 165 from Huntsman Chemicals), ethoxylated alkanolamides (e.g., EMPILAN® MAA series from Huntsman Chemicals), ethylene glycol esters (e.g., EMPILAN® EG series from Huntsman Chemicals), fatty acid alkanolamides (e.g., EMPILAN® CD series from Huntsman Chemicals), fatty alcohol alkoxylates (e.g., SURFONIC® LF series from Huntsman Chemicals), lauryl alcohol ethoxylates (e.g., TERIC® 12A series from Huntsman Chemicals), mono-branched alcohol ethoxylates (e.g., EMPILAN® KCA series from Huntsman Chemicals), nonyl phenol ethoxylates (e.g., SURFONIC® N series from Huntsman Chemicals), octyl phenol ethoxylates (e.g., SURFONIC® OP series from Huntsman Chemicals), random copolymer alkoxylates (e.g., HYDROL® series from Huntsman Chemicals), sorbitan ester ethoxylates (e.g., ECOTERIC® T series from Huntsman Chemicals), stearic acid ethoxylates (e.g., TERIC® SF series from Huntsman Chemicals), synthetic alcohol ethoxylates (e.g., EMPILAN® KH series from Huntsman Chemicals), tall oil fatty acid ethoxylates (e.g., TERIC® T series from Huntsman Chemicals), tallow amine ethoxylates (e.g., EMPILAN® AMT series from Huntsman Chemicals), ethoxylates of linear oleochemical alcohols (e.g., Lutensol® A grades from BASF Corp.), oxo alcohol ethoxylates that are based on predominately linear alcohols (e.g., Lutensol® AO grades from BASF Corp.), alkylphenol ethoxylates (e.g., Lutensol® AP grades from BASF Corp.), alkylpolyethylene glycol ethers made from a linear, saturated C Cis fatty alcohol (e.g., Lutensol® AT grades from BASF), a Cs-C-io alcohol with an average of approximately 6 or 8 moles of ethylene oxide per mole of alcohol (Surfonic® L12-6 or Surfonic® L12-8 from Huntsman Chemicals, respectively), nonylphenoxypoly(ethyleneoxy)ethanol, with a degree of polymerization ranging from 9 to 10 (Surfonic® N-95 from Huntsman Chemicals), a Cs-C alkyl polyglucoside with a degree of polymerization ranging from 1 to 3, e.g., Cs-C-io alkyl polyglucoside with a degree of polymerization of 1.5 (Glucopon® 200), Cs-C alkyl polyglucoside with a degree of polymerization of 1.45 (Glucopon® 425), or C12-C16 alkyl polyglucoside with a degree of polymerization of 1 .6 (Glucopon® 625), and polyethoxylated polyoxypropylene block copolymers (poloxamers) including by way of example the Pluronic® poloxamers commercialized by BASF Chemical Co. In a preferred embodiment, the nonionic surfactant includes an alcohol ethoxylate, such as Neodol® 91 -8 or Surfonic® L12-8. In certain embodiments, an alcohol ethoxylate is the only nonionic surfactant present.

[0020] In certain embodiments, the bactericidal activity of the compositions of the present invention may be due to the presence of a specific combination of a glycolic acid and one or more anionic surfactants, and, optionally a nonionic surfactant. In certain embodiments, the yeasticidal activity of the compositions may be due to the presence of salicylic acid, especially when combined with glycolic acid and the one or more anionic surfactants.

[0021 ] In one or more embodiments, the antimicrobial activity (bactericidal and yeasticidal activity) of the compositions of the present invention may be due to the presence of a specific combination of glycolic acid, salicylic acid, and SLS. Optionally, these compositions may further comprise one or more of an alcohol ethoxylate surfactant, an a-olefin sulfonate, and an alkane sulfonate, and preferably all three.

[0022] In various embodiments, the glycolic acid may be present in an amount of at least 0.05, 0.1 , 0.5, 0.75, 0.9, 1 , 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, or 6 wt. %. In the same or alternative embodiments, the glycolic acid may be present in an amount of not more than 10, 9.5, 9, 8.5, 8, 7.5, 7, 6.5, 6, 5.5, 5, 4.5, or 4 wt. %. For example, in one or more embodiments, the glycolic acid may be present in an amount of from 0.5-10 wt. %, 0.75-5 wt. %, or 0.9-3.5 wt. %. [0023] In various embodiments, the salicylic acid may be present in an amount of at least 0.1 , 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, or 0.5 wt. %. In the same or alternative embodiments, the salicylic acid may be present in an amount of not more than 1 , 0.8, 0.75, 0.7, 0.65, 0.6, 0.55, 0.50, 0.45, or 0.4 wt. %. For example, in one or more embodiments, the salicylic acid may be present in an amount of from 0.15-0.6 wt. %, 0.2- 0.55 wt. %, or 0.25-0.5 wt. %.

[0024] In various embodiments, one or more anionic surfactants (e.g., alkane sulfonate, SLS and/or alpha-olefin sulfonate) may each be present in an amount of at least 0.01 , 0.05, 0.1 , 0.2, 0.5, 1 ,1.5, or 2 wt. %. In the same or alternative embodiments, one or more anionic surfactants may be present in an amount of not more than 5, 4.5, 4, 3.5, 3, 2.5, 2, 1.5, or 1 wt. %. For example, in certain embodiments, one or more anionic surfactants may each be present in an amount of from 0.01 to 5 wt. %, 0.05 to 3 wt. %, or 0.1 to 2 wt. %.

[0025] In various embodiments, the nonionic surfactant may be present in an amount of at least 0.001 , 0.005, 0.01 , 0.05, 0.1 , 0.2, 0.3, 0.4, 0.5, 1 , 2, or 2.5 wt. %. In the same or alternative embodiments, the nonionic surfactant may be present in an amount of not more than 10, 7.5, 6.5, 5.5, 5, 4.5, 4, 3.5, 3, 2.5, 2, 1.5, 1 , 0.5, 0.4, or 0.3 wt. %. For example, in one or more embodiments, the nonionic surfactant may be present in an amount of from 0.01 -10 wt.%, 0.05-5 wt. %, or 0.1 -1 wt.%

[0026] In certain embodiments, the total concentration of anionic and nonionic surfactants is at least 0.05, 0.1 , 0.5, 0.75, 1 , 1 .25, 1.5, 1 .75, or 2 wt. %. In the same or alternative embodiments, the total concentration of anionic and nonionic surfactants is not more than 10, 7.5, 5, 3, or 2.5 wt. %. For example, in one or more embodiments, the total concentration of anionic and nonionic surfactants is from 0.05 to 10 wt. %, 0.1 to 5 wt. %, or 0.5 to 3 wt. %.

[0027] In one or more embodiments, the compositions of the present invention comprise at least two anionic surfactants and a nonionic surfactant. In particular embodiments, the weight ratio between the total amount of organic acid and the total anionic surfactant concentration is from 5:1 to 1 :2, from 3:1 to 1 :1 , or from 2:1 to 1.25:1.

[0028] In one or more embodiments, the composition is aqueous comprising water in an amount ranging from at least 50, 60, 70, or 75 wt. %, and/or not more than 99, 97, 95, or 90 wt. %. For example, in certain embodiments, water may be present in amount ranging from 60 to 90 wt. %, 65 to 85 wt. %, or 70 to 80 wt. %. A non-limiting list of solvents includes water, an alcohol, propylene glycol, glycol ethers and/or alcohols. In certain embodiments, a mixture of two or more of the aforementioned solvents may be used.

[0029] The antimicrobial compositions of the present invention may include one or more additives, such as a buffering agent, an emollient, a humectant, a preservative, a barrier forming agent, a surfactant or wetting agent, a foaming agent, a viscosity control agent, a colorant, an opacifying agent, a skin conditioning agent, and an additional antimicrobial agent.

[0030] Barrier and film forming agents can be used in compositions formulated as teat dips so that the composition remains in contact with the teat between milking cycles. Barrier and film forming agents coat the teat skin and, optionally, the udder. Barrier agents may form a plug at the end of the open teat canal. Typical barrier and film forming agents include thick creams or emollients (made with viscosity control agents), films, polymers, latex and the like. Some nonionic surfactants may help further enhance the barrier properties of a composition, in addition to contributing to surface wetting. Examples of such surfactants may include, without limitation, polyoxyethylenepolyoxypropylene glycol (marketed as Pluronic® F108). Another commonly used barrier agent is marketed as Pluronic® P105. A latex material that provides an effective covering of the teat is described in U.S. Pat. No. 4,113,854, hereby incorporated by reference. Suitable barrier forming agents include, for example, latex, arabinoxylanes, glucomannanes, guar gum, johannistree gums, cellulose, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxymethyl cellulose, carboxyethyl cellulose, carboxymethyl cellulose, starch, hydroxyethyl starch, gum arabic, curdlan, pullulan, dextran, maltodextran, polysulfonic acid, polyacryl amide, high molecular weight polyacrylate, high molecular weight cross-linked polyacrylate, carbomer, sodium alginate, sodium alginate cross-linked with calcium salt, xanthan gum, poly(vinyl alcohol) (PVA) and poly(N-vinylpyrrolidone) (PVP). Preferred embodiments for barrier-forming agents include xanthan gum, carboxymethyl cellulose, sodium alginate, sodium alginate cross- linked with calcium salt, PVA, hydroxyethyl cellulose, PVP, and (2,5-dioxo-4- imidazolidinyl)-urea (Allantoin).

[0031 ] In certain embodiments, the compositions of the present invention may include a modified polysaccharide as a barrier film-forming agent to form a long-lasting persistent, continuous, uniform barrier film when applied to the skin. Such compositions have particular utility as barrier teat dips that are used prophylactically against mastitis. Such compositions may include relatively low molecular weight polysaccharides, for example, as may be derived specifically from hydrolyzed starch. Such compositions that are capable of forming a long-lasting, persistent, continuous, uniform barrier film may contain from about 0.1 % to about 20% by weight of modified or hydrolyzed polysaccharide material for use as the barrier forming agent. The polysaccharide material may have a majority polysaccharide component as starch, modified starch, hydrolyzed starch, a starch derivative, and combinations thereof. In certain embodiments, the majority polysaccharide components may have overall or average Dextrose Equivalence (DE) value ranging from 2 to 50, and this value more preferably ranges from 3 to 27. In this sense, the term “majority polysaccharide component” is used to describe a majority weight percentage of all polysaccharides in the composition, i.e. , more than 50% of all polysaccharides in the composition.

[0032] In certain embodiments, a foaming agent may be used in the disclosed antimicrobial compositions. A foaming agent aerates a liquid composition to produce a foam that may increase surface area of the composition and improve contact with the surface to be treated (e.g., an animal hoof or a teat). Typically, a foaming agent is in the form of a compressed gas, or a material that will decompose to release gas under certain conditions. Suitable gases include but are not limited to nitrogen, argon, air, carbon dioxide, helium and mixtures thereof. In addition, solid carbon dioxide (dry ice), liquid nitrogen, hydrogen peroxide and other substances that release gas via a change in state or through decomposition are contemplated for use with the present compositions. Typically, a high foaming surfactant, such as sodium lauryl sulfate, dodecylbenzene sulfonic acid, sodium alkylaryl polyether sulfate, sodium lauryl ether sulfate, sodium decyl sulfate, cocamine oxide, or C12-C14 whole coconut amido betaines, can be used to generate a stable foam. The foam may be produced when agitation in the form of a compressed gas is mixed with the solution either by bubbling the gas into the solution or spraying the solution or solution-gas mixture through spray equipment. In certain embodiments, foam may also be generated by the mechanical action, or by other mechanical means that mix atmospheric air with the composition.

[0033] Surfactants are well known for foaming and are widely used as foaming agents in hand soap and manual/hand dishwashing detergents and may also be used as foaming agents in applications where foaming boosts the performance and increases the contact time of the composition to particular substrates. Examples of such suitable anionic surfactants can be chosen from a linear alkyl benzene sulfonic acid, a linear alkyl benzene sulfonate, an alkyl a-sulfomethyl ester, an a-olefin sulfonate, an alcohol ether sulfate, an alkyl sulfate, an alkylsulfo succinate, a dialkylsulfo succinate, and alkali metal, alkaline earth metal, amine and ammonium salts thereof. Specific examples are linear C10-C16 alkyl benzene sulfonic acid, linear C10-C16 alkyl benzene sulfonate or alkali metal, alkaline earth metal, amine and ammonium salts thereof, e.g., sodium dodecylbenzene sulfonate, sodium C14-C16 a-olefin sulfonate, sodium methyl a-sulfomethyl ester and disodium methyl a-sulfo fatty acid salts. Suitable nonionic surfactants may be chosen from an alkyl polyglucoside, an alkyl ethoxylated alcohol, an alkyl propoxylated alcohol, an ethoxylatedpropoxylated alcohol, sorbitan, sorbitan ester, and an alkanol amide. Specific examples include Cs-C alkyl polyglucoside with a degree of polymerization ranging from 1 to 3 e.g., Cs-C-io alkyl polyglucoside with a degree of polymerization of 1 .5 (Glucopon® 200), Cs-Cie alkyl polyglucoside with a degree of polymerization of 1.45 (Glucopon® 425), C12-C16 alkyl polyglucoside with a degree of polymerization of 1 .6 (Glucopon® 625). Amphoteric surfactants can be chosen from alkyl betaines and alkyl amphoacetates. Suitable betaines include cocoamidopropyl betaine, and suitable amphoacetates include sodium cocoamphoacetate, sodium lauroamphoacetate and sodium cocoamphodiacetate. Alkyl amine oxides based on C12-C14 alkyl chain length feedstock such as those derived from coconut oil, palm kernel oil may also be suitable foaming agents.

[0034] In one or more embodiments, viscosity control agents may be added to formulate the antimicrobial compositions according to an intended environment of use. In one example, it may be advantageous for some compositions to have an optimized solution viscosity to impart vertical clinging of the product onto a teat. This type of viscous product, especially one having a suitable thixotropic, pseudoplastic or viscoelastic gel strength, minimizes dripping of the product to avoid wastage and is particularly advantageous in teat dip compositions. Teat dip compositions may benefit from a preferred dynamic viscosity ranging from 1 cPs to 3000 cPs. Other applications including hard surface disinfectants have a preferred dynamic viscosity ranging from about 1 cPs to 300 cPs. In another example, the amount of viscosity control agents may be substantially reduced or even eliminated in other compositions, such as surface or floor disinfectants where easy cleanup is desired. An intermediate or medium viscosity composition may be useful in a hand cleaner or personal care product. It is within the scope of the present invention for the antimicrobial compositions to be formulated for a wide variety of applications by altering the amount of viscosity control agents. The viscosity referred to throughout this application is Brookfield viscosity measured in cPs by a Brookfield LV viscometer at ambient temperature (25° C.) with either spindle # 1 @ 60 - 100 rpm or spindle # 2 @ 15 to 30 rpm. In various embodiments, a thickener may be added to achieve a viscosity range of from 50 cPs to 10000 cPs, or from 100 cPs to 4000 cPs.

[0035] Suitable viscosity control agents include hemicellulose, for example arabinoxylanes and glucomannanes; plant gum materials, for example guar gum and johannistree gums; cellulose and derivatives thereof, for example methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, hydroxyethyl cellulose or carboxymethyl cellulose; starch and starch derivatives, for example hydroxyethyl starch or cross linked starch; microbial polysaccharides, for example xanthan gum, sea weed polysaccharides, for example sodium alginate, carrageenan, curdlan, pullulan or dextran, dextran sulfate, whey, gelatin, chitosan, chitosan derivatives, polysulfonic acids and their salts, polyacrylamide, and glycerol. Preferred viscosity controlling agents are xantham gum, different types of cellulose and derivatives thereof, particularly hydroxyalkyl cellulose, methyl cellulose, and glycerol. In addition, high molecular weight (MW>1 ,000,000) crosslinked polyacrylic acid type thickening agents may be used, such as those sold by B.F. Goodrich (now Lubrizol) under their Carbopol® trademark, especially Carbopol® 941 , which is the most ion-insensitive of this class of polymers, Carbopol® 940, and Carbopol® 934. The Carbopol® resins, also known as “Carbomer”, are reported in U.S. Pat. No. 5,225,096 (hereby incorporated by reference into the present application), and are hydrophilic high molecular weight, cross-linked acrylic acid polymers. Carbopol® 941 has a molecular weight of about 1 ,250,000, Carbopol® 940 has a molecular weight of approximately 4,000,000, and Carbopol® 934 has a molecular weight of approximately 3,000,000. The Carbopol® resins are cross-linked with polyalkenyl polyether, e.g. about 1 % of a polyallyl ether of sucrose having an average of about 5.8 alkyl groups for each molecule of sucrose. Further detailed information on the Carbopol® resins is available from B.F. Goodrich (Lubrizol), see for example, the B. F. Goodrich catalog GC-67, Carbopol® Water Soluble Resins. Clays and modified clays such as bentonite or laponite can also be used as thickeners. Co-thickeners may be added to improve the stability of the gel matrix, for example, colloidal alumina or silica, fatty acids or their salts may improve gel stability. Further, the viscosity control agent may include carboxymethyl cellulose, sodium alginate, sodium alginate cross-linked with calcium salt, polysulfonic acids and their salts, polyacrylamide, polyvinyl alcohol (PVA), hydroxyethyl cellulose and poly-N-vinylpyrrolidone) (PVP).

[0036] In one or more embodiments, a buffering agent, or a pH adjusting agent may be added to the disclosed compositions. A composition pH value may be selectively adjusted by the addition of acidic or basic ingredients. Generally, an acidic pH is preferred. Suitable acids for use as pH adjusting agents may include, for example, citric acid, formic acid, acetic acid, lactic acid, phosphoric acid, phosphorous acid, sulfamic acid, nitric acid, nitrous acid and hydrochloric acid. It will be recognized by those skilled in the art that the organic acid, e.g., glycolic acid, selected as the antimicrobial organic acid will also influence pH, and thus, have an adjusting effect as discussed in this paragraph. Mineral acids may be used to drastically lower the pH. The pH may be raised or made more alkaline by addition of an alkaline agent such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, monosodium acid diphosphonate or combinations thereof. Traditional acid buffering agents such as citric acid, lactic acid, and phosphoric acid may also be used to maintain a desired pH. The pH value of the composition may be adjusted by the addition of acidic or basic or buffering materials. [0037] The physical property of pH may be adjusted by acid or base addition and is broadly preferred in the range of from about 2.0 to about 8.0 for use in teat dip compositions and other compositions that are intended to contact the skin. More preferred ranges include about 2.0 to about 7.5, about 2.2 to about 6.0, and about 2.5 to about 4.5. Hard surface and commercial disinfectants may be provided with lower pH values, such as about 2.0 or about 1 .0.

[0038] As discussed above, in certain embodiments, the inventive compositions may include a wetting agent. Wetting agents or surface-active agents are also known as surfactants. Typical wetting agents are used to wet the surface of application, reduce surface tension of the surface of application so that the product can penetrate easily on the surface and remove unwanted soil. The wetting agents or surfactants of the disclosed compositions may increase overall detergency of the formula, solubilize or emulsify some of the organic ingredients that otherwise would not dissolve or emulsify, and facilitate penetration of active ingredients deep onto the surface of the intended application surfaces, such as teat skin.

[0039] Suitable surfactants used as wetting agents in the present invention include anionic, cationic, nonionic, zwitterionic, and amphoteric surfactants. Wetting agents and surfactants used in the inventive applications can be high foaming, low foaming, and non-foaming type. Suitable anionic surfactants can be chosen from a linear alkyl benzene sulfonic acid, a linear alkyl benzene sulfonate, an alkyl a-sulfomethyl ester, an a-olefin sulfonate, an alcohol ether sulfate, an alkyl sulfate, an alkylsulfo succinate, a dialkylsulfo succinate, and alkali metal, alkaline earth metal, amine, and ammonium salts thereof. Specific examples include a linear C10-C16 alkyl benzene sulfonic acid or alkali metal, alkaline earth metal, amine, and ammonium salts thereof, e.g., sodium dodecylbenzene sulfonate; sodium C14-C16 a-olefin sulfonate; sodium methyl a- sulfomethyl ester; and disodium methyl a-sulfo fatty acid salt. Suitable nonionic surfactants can be chosen from an alkyl polyglucoside, an alkyl ethoxylated alcohol, an alkyl propoxylated alcohol, an ethoxylatedpropoxylated alcohol, sorbitan, sorbitan ester, an alkanol amide. Specific examples include Cs-C alkyl polyglucoside with a degree of polymerization ranging from 1 to 3, e.g., Cs-C-io alkyl polyglucoside with a degree of polymerization of 1.5 (Glucopon® 200), Cs-C alkyl polyglucoside with a degree of polymerization of 1.45 (Glucopon® 425), C12-C16 alkyl polyglucoside with a degree of polymerization of 1.6 (Glucopon® 625), and polyethoxylated polyoxypropylene block copolymers (poloxamers) including by way of example the Pluronic® poloxamers commercialized by BASF Chemical Co. Amphoteric surfactants can be chosen from alkyl betaines and alkyl amphoacetates. Suitable betaines include cocoamidopropyl betaine, and suitable amphoacetates include sodium cocoamphoacetate, sodium lauroamphoacetate and sodium cocoamphodiacetate.

[0040] It will be recognizable to those skilled in the art that because at least one anionic surfactant and, optionally at least one nonionic surfactant, are included as in the antimicrobial compositions of the present invention, these surfactants may also have an influence on the wetting properties of the mixture.

[0041 ] An opacifying agent or dye may be optionally included in the present compositions. For example, color on a teat tells a farmer that a particular cow has been treated. To preclude any problems with possible contamination of milk, it is preferred that FD&C Certified (food grade) dyes be used. There are many FD&C dyes available, such as FD&C Red #40 (E129), FD&C Yellow #6 (E110), FD&C Yellow #5 (E102), and FD&C Blue #1 (E133). Dyes used either alone or in combination are preferred. D&C Orange #4 can also be used. Titanium dioxide (TiO2) is widely used as an opacifier and can also be used in combination with various colorants.

[0042] In certain embodiments, a preservative may be included in the inventive compositions. A non-limiting list of preservatives includes ethylenediaminetetraacetic acid (EDTA) and its alkali salts, paraban, methyl paraban, ethyl paraban, glutaraldehyde, benzyl alcohol, and low molecular weight alcohols having a carbon number less than five. In one or more embodiments, more than one type of preservative may be utilized. It is known to one skilled in the art that chelating agents, such as EDTA, function as preservatives by sequestering or removing metal ions from hard water. The metal ions, if not removed from the composition, serve as reaction sites for enzymes within the bacteria; the metalloenzyme reactions produce energy for bacterial cell replication.

[0043] In certain embodiments, one or more skin conditioning agents may be included in the inventive compositions. Skin conditioning agents may provide extra protection for human or animal skin prior to or subsequent to being exposed to adverse conditions. For example, skin conditioning agents may include moisturizers, such as glycerin, sorbitol, propylene glycol, D-Panthenol, Poly Ethylene Glycol (PEG) 200-10,000, Poly Ethylene Glycol Esters, Acyl Lactylates, Polyquaternium-7, Glycerol Cocoate/Laurate, PEG-7 Glycerol Cocoate, Stearic Acid, Hydrolyzed Silk Peptide, Silk Protein, Aloe Vera Gel, Guar Hydroxypropyltrimonium Chloride, Alkyl Poly Glucoside/Glyceryl Luarate, shea butter and coco butter; sunscreen agents, such as titanium dioxide, zinc oxide, octyl methoxycinnamate (OMC), 4-methylbenzylidene camphor (4-MBC), oxybenzone and homosalate; and itch-relief or numbing agents, such as aloe vera, calamine, mint, menthol, camphor, antihistamines, corticosteroids, benzocaine and paroxamine HCI.

[0044] In certain embodiments, the antimicrobial compositions of the present invention may be used in combination with traditional antimicrobial agents to achieve effective kill rates at lower concentrations of traditional antimicrobial agents than those typically used when the traditional antimicrobial agents provide the sole source of antimicrobial activity.

[0045] Traditional antimicrobial agents include iodophors, quaternary ammonium compounds, hypochlorite releasing compounds (e.g. alkali hypochlorite, hypochlorous acid), oxidizing compounds (e.g. peracids and hypochlorite), carboxylic acids (e.g. heptanoic, octanoic, nonanoic, decanoic, undecanoic acids), acid anionics (e.g. alkylaryl sulfonic acids, aryl sulfonic acid, alkyl sulfonic acids, alkylaryl sulfuric acid, aryl sulfuric acid, alkyl sulfuric acid, alkylaryl sulfuric acid), chlorine dioxide from alkali chlorite by an acid activator, and bisbiguanides such as chlorhexidine. Phenolic antimicrobial agents may be chosen from 2,4,4'-trichloro-2"-hydroxydiphenylether, which is known commercially as triclosan and may be purchased from Ciba Specialty Chemicals as IRGASAN™ and IRGASAN DP 300™. Another such antimicrobial agent is 4-chloro- 3,5-dimethyl phenol, which is also known as PCMX and is commercially available as NIPACIDE PX and NIPACIDE PX-P. Other traditional germicides include formaldehyde releasing compounds such as glutaraldehyde and 2-bromo-2-nitro-1 ,3-propanediol (Bronopol), polyhexamethyl biguanide (CAS 32289-58-0), guanidine salts such as polyhexamethylene guanidine hydrochloride (CAS 57028-96-3), polyhexamethylene guanidine hydrophosphate (89697-78-9), and poly[2-(2-ethoxy)-ethoxyethyl]-guanidinium chloride (CAS 374572-91 -5) and mixtures thereof.

[0046] In one embodiment, the disclosed antimicrobial compositions may be used in combination with traditional antimicrobial agents, such as copper sulfate, zinc sulfate, sulfamethazine, quaternary ammonium compounds, hydrogen peroxide and/or peracetic acid, for example, to achieve an effective kill at lower concentrations of traditional antimicrobial agents.

[0047] In one or more embodiments, the antimicrobial compositions of the present invention do not include hydrogen peroxide (or hydrogen peroxide generating compounds), chlorine dioxide (or chlorine dioxide generating compounds), chlorhexidine, iodophors, and/or iodine. In one or more embodiments, the antimicrobial compositions of the present invention are iodine free. In certain embodiments, the antimicrobial compositions of the present invention are hydrogen peroxide free. In one or more embodiments, the antimicrobial compositions of the present invention are chlorhexidine free. In certain embodiments, the antimicrobial compositions of the present invention are chlorine dioxide free. In certain embodiments, the antimicrobial compositions are lactic acid free.

[0048] The antimicrobial compositions of the present invention may provide a substantial reduction in Gram positive and Gram negative bacteria, as well other numerous classes of microbes. In particular embodiments, the reduction may be at least a three, four, five, or six log reduction in Gram positive and/or Gram negative bacteria. In certain embodiments, the antimicrobial compositions may exhibit a substantially complete kill that is at least a five log (99.999%) reduction in bacterial populations. In particular embodiments, the antimicrobial compositions may provide any of the foregoing log reductions within one minute, 45 seconds, or 30 seconds of contact time when tested according to EN 1656, at 30°C, as described in the Examples below.

[0049] The antimicrobial compositions of the present invention may provide a substantial reduction in fungi, especially yeast. In particular embodiments, the reduction may be at least a two, three, or four log reduction in fungi, and yeast in particular. In certain embodiments, the antimicrobial compositions may exhibit a substantially complete kill that is at least a four log reduction in yeast populations In particular embodiments, the antimicrobial compositions may provide any of the foregoing log reductions within two minutes, one minute, or 30 seconds of contact time when tested according to EN 1657, at 30°C, as described in the Examples below.

[0050] The antimicrobial compositions of the present invention may comprise components that assist in providing low temperature stability for the compositions. Preferred cold temperature-stabilizing components include, but are not limited to, propylene glycol and magnesium oxide. In certain embodiments, the compositions are storage stable for at least one week, at least one month, at least three months, or at least six months at 4°C. As used herein, the term “storage stable” refers to the characteristic of the compositions that various components present within the composition do not separate out from the other components following formulation and until usage, or until at least passage of a specified period of time. Compositions according to certain embodiments of the present invention are formulated so that these components that may not be particularly highly water soluble, or that may interact with other components to precipitate out, remain suspended and/or in solution for the indicated periods of time under low temperature storage conditions.

[0051 ] In certain embodiments, the antimicrobial compositions may be used for prophylactic treatment of a dairy animal's teats to provide a long lasting persistent protective germicidal barrier film that demonstrates persistence between milkings, and is controllably reproducible to yield a continuous, uniform persistent barrier. This treatment process may include milking the animal, coating the teats with the composition after milking, allowing the composition to dry and so also form a layer of persistent barrier film on the teats. In certain other embodiments, the compositions of the present invention may be used as a germicide on an animal’s teats but may not form a long-lasting persistent barrier film on the teats. In various embodiments, the composition may be applied topically by painting, foaming, dipping or spraying. Furthermore, use of the composition is not limited to use against mastitis, and the composition may be used generally to treat or protect against any infectious skin condition.

[0052] In preferred embodiments, the antimicrobial compositions may be used to clean and/or disinfect a dairy animal’s teats prior to milking in order to avoid contamination of the milk produced from the animal with various bacteria and yeasts. The antimicrobial compositions may also be applied post-milking, in a barrier or non-barrier form, in order to clean and/or disinfect the dairy animal’s teats thereby lessening the animal’s chances of developing mastitis.

[0053] In certain other embodiments, the antimicrobial compositions of the present invention may be used, for example, in any manner where application of antimicrobial agents is desired. In one or more embodiments, the antimicrobial compositions of the present invention may be used as a hand sanitizer, a skin cleanser, a surgical scrub, a wound care agent, a disinfectant, a mouthwash, a bath/shower gel, a hard surface sanitizer and the like. Preferred compositions for skin applications have a pH of about 2.0 to about 8.0 and provide a substantial reduction, e.g., greater than a five- log reduction (99.999%), in Gram positive and Gram negative bacterial populations. In certain embodiments, the antimicrobial compositions of the present invention may be applied as a wound healing agent, where the composition assists in a faster and qualitatively improved healing of wounds by decreasing the number of microorganisms in the vicinity of the wound.

[0054] In one or more embodiments, the antimicrobial compositions of the present invention may be non-irritating when topically applied to animal or human skin. A composition may be determined to be non-irritating based on its Lysis/Denaturation (L/D) ratio as determined by Blood Cell Irritation testing.

[0055] The Blood Cell Irritation tests measures the L/D ratio of a particular composition and is used to determine if a particular composition is mild enough for topical application to the skin or human or animal. Measuring the L/D ratio requires measuring the half haemolysis value (H50) and the denaturation index (DI). The H50 value relates to the tendency of the red blood cells to rupture when in contact with the test product. The DI value relates to the denaturation of protein caused by the test product.

[0056] Haemolysis Values (H50); Product Denaturation Index Values (DI); and Lysis/Denaturation Ratios (L/D) can be determined for the compositions using known methods. Descriptions of these methods are disclosed by Wolfgang J. W. Pape, Udo Hoppe: In vitro Methods for the Assessment of Primary Local Effects of Topically Applied Preparations, Skin Pharmacol. (1991 ), 4, 205-212, which is incorporated herein by reference. [0057] These methods involve separating red blood cells and then exposing them to the test compositions. To separate the red blood cells, 50 mL of sodium citrate buffer (17.03 g trisodium citrate+8.45 g citric acid diluted to 1 L with bacteria-free DI water) is added to every 450 mL of fresh calf blood and mixed. The blood is then centrifuged to isolate the red blood cells (RBC), which are then washed with phosphate buffered saline solution (PBS) (3.15 g of Na₂HPO₄ + 0.762 g of KH2PO4 + 7.21 g of NaCI + 1.8 g of glucose diluted to 1 L with bacteria-free DI water), and centrifuged several times to remove white cells and plasma, according to a known method. The red blood cells (“RBC stock”) are then placed into containers for use in testing the compositions of interest.

[0058] Further, a Standard Surfactant Solution is prepared that includes 1000 ppm sodium lauryl sulfate in PBS. Also, this Standard Surfactant Solution is diluted to 0 ppm, 20 ppm, 30 ppm, and 40 ppm. A Test Product Solution is also prepared, which includes 1000 ppm test product in PBS. In addition, this Test Product is diluted to 0 ppm, 25 ppm, 50 ppm, and 100 ppm.

[0059] To measure the H50 value of a test formulation, the H50 value of the Standard Surfactant Solution is first measured. 0.25 mL of adjusted RBC stock suspension is mixed with 9.75 mL of the 40 ppm Standard Surfactant Solution. The mixture is then shaken for 10 minutes and centrifuged for 3 minutes at 5000 rpm to precipitate any intact RBC. The absorbance at 560 nm is measured using the 0 ppm test Standard Surfactant Solution as a blank. This procedure is then repeated for the 20 ppm and 30 ppm Standard Surfactant Solutions. A graph of concentration in ppm vs. absorbance at 560 nm is plotted for the Standard Surfactant Solution. The H50 concentration is the concentration where the absorbance is equal to half the absorbance of the 100% haemolysis value (H100), which is determined by mixing 0.25 mL of adjusted RBC Stock with 9.75 mL of DI water, then shaking the mixture for 10 minutes, and then measuring the absorbance at 560 nm. The half-maximal haemolytic concentration of sodium lauryl sulfate is 22 + 4 ppm. Obtaining a value in this range confirms that the proper procedure is being followed.

[0060] The H50 value of the Test Product is then measured. 0.25 mL of adjusted RBC Stock suspension is mixed with 9.75 mL of one of the Test Product solutions. The mixture is then shaken for 10 minutes and centrifuged for 3 minutes at 5000 rpm to precipitate any intact RBC. The absorbance at 560 nm is measured using the 0 ppm Test Product sample as a blank. These steps are repeated for each concentration of Test Product solutions. A graph of concentration in ppm vs. absorbance at 560 nm for the Test Product is then plotted. The H50 concentration is the concentration where the absorbance is equal to half the absorbance of the H100. If necessary, additional concentrations of the test product can be prepared so the H50 can be measured accurately.

[0061 ] To determine the DI value, the Standard Surfactant Denaturation Index R2 value is measured. 0.25 mL of adjusted RBC Stock suspension is mixed with 9.75 mL of the OOppm Standard Surfactant Solution. The mixture is then shaken for 10 minutes and centrifuged for 3 minutes at 5000 rpm to precipitate any intact RBC. All of the RBC should dissolve. The absorbance at 575 nm and 540 nm is measured using the 0 ppm Standard Surfactant Solution as a blank. The ratio of ABS575/ABS540 is equal to R2. R2 is approximately equal to 0.8. Obtaining a value in this range confirms that the proper procedure is being followed.

[0062] The DI value of the Test Product is determined by first mixing 0.25 mL of adjusted RBC Stock suspension with 9.75 mL of the 1000 ppm Test Product solution. The mixture is then shaken for 10 minutes and centrifuged for 3 minutes at 5000 rpm to precipitate any intact RBC. All of the RBC should dissolve. If the RBC are not completely dissolved, repeat with a higher concentration of Test Product. The absorbance at 575 nm and 540nm is measured using the 0 ppm Test Product solution as a blank. The ratio of ABS575/ABS540 is equal to Ri. The Ri and R2 values are then used to calculate the DI from formula 1 below.

DI (%) = 100 (1 .05 - Ri)/( 1 .05 - R2) Formula 1

[0063] The H50 score, which measures haemolysis alone, usually shows a similar irritation correlation to the L/D ratio. The higher the ppm value for H50 the less irritating the product. A crude scale is H50>500 ppm (non-irritant); 120-500 (slight irritant), 30-120 (moderate irritant), 10-30 (irritant), 0-10 (strong irritant). In certain embodiments, the antimicrobial compositions of the present invention may exhibit an H50 value of at least 300, 400, 500, 600, 700, or 800 ppm. [0064] The DI score, which measures denaturation of protein also shows a correlation to the L/D ratio. A crude scale is DI 0-5% (non-irritant); 5-10% (slight irritant), 10-75% (moderate irritant), 75-100% (irritant), and >100% (strong irritant). In certain embodiments, the antimicrobial compositions of the present invention may exhibit a DI score of less than about 10, 7, 5, 3, 1 , 0.5, or 0.3%.

[0065] However, as discussed above, the L/D ratio is the primary value typically used to determine irritation. An L/D value greater than 100 is an indication that the composition is a non-irritant; levels between 10 and 100 are considered slight irritants; levels between 1 and 10 are considered moderate irritants; levels between 0.1 to 1 are considered irritants; and levels lower than 0.1 are considered strong irritants. In certain embodiments, the antimicrobial compositions of the present invention exhibit an L/D ratio of at least 100, 150, 200, 250, or 300. In certain embodiments, skin conditioning and moisturizing agents are at best unnecessary, and at least may be minimized in a particular product.

[0066] Methods of preparing the antimicrobial compositions of the present invention may involve dissolving a desired concentration of antimicrobial agents and, optionally, any desired additives in a selected solvent, namely water. The solution is then mixed, for example in a mixer, to form a final antimicrobial composition.

[0067] In certain embodiments, the components of the disclosed antimicrobial compositions fall within the ranges set forth in Tables I and II below. Table I identifies exemplary ready-to-use antimicrobial compositions in accordance with certain embodiments of the present invention.

Table I

[0068] Table II describes preferred ready-to-use antimicrobial compositions in accordance with certain embodiments of the present invention.

Table

[0069] Through experimentation, as shown in the Examples below, it has been discovered that the use of salicylic acid, glycolic acid, and at least one anionic surfactant provides antimicrobial compositions that are efficacious as bactericides and yeasticides. In addition, the compositions can be formulated to be physically stable at cold temperatures.

EXAMPLES

[0070] This invention can be further illustrated by the following Examples of embodiments thereof, although it will be understood that these examples are included merely for the purposes of illustration and are not intended to limit the scope of the invention unless otherwise specifically indicated.

[0071] It should be recognized that in the below Examples, each component’s concentration is 100% active unless that component is expressly identified as having a certain percentage of active versus inert ingredients. For example, if a component is listed as “Glycolic acid, 70%” and is shown to be present at 4.28 wt. %, this means that glycolic acid is present in that composition at 3 wt % (0.7 * 4.28 wt. %).

Example 1: Microbiological Activity of Formulations Having Varying Concentrations of Salicylic Acid, Glycolic Acid, and Anionic Surfactants

[0072] Various standardized test methods are in place for comparatively testing the efficacy of antimicrobial agents. For purposes of the experiments reported herein, test methods EN 1656 (bactericidal activity) and EN 1657 (yeasticidal activity), modified as discussed below, are used. These standards are hereby incorporated by reference to the same extent as though fully disclosed herein.

[0073] The microorganisms (E. coli (ATCC 11229), S. aureus (ATCC 6538), and Streptococcus uberis) are prepared from glycerol stocks that are spread onto tryptic soy agar plates and allowed in incubate for 24 hours. This is the stock culture. A subculture is then prepared from the stock culture by streaking tryptic soy agar plates and allowing incubation for 24 hours. Second and third subcultures are prepared from the first subculture in the same way. These subcultures are the working cultures. Loopfuls of the working cultures are then transferred to diluent to create a standardized cell suspension, this suspension is used in the testing against the compositions. The bacteria were diluted to form a suspension having an initial concentration of about 10⁸ cfu/mL.

[0074] A mixture of 10 g/L bovine albumin and 10 g/L yeast extract was used as an interfering substance under high soil conditions, and 3 g/L bovine albumin was used as interfering substance under low soil conditions, in testing under EN 1656 protocol. Yeast extract comprises the cell contents of yeast without the cell walls and are often used as food additives or flavorings, or as nutrients for bacterial culture media.

[0075] 1 mL of interfering substance and 1 mL of bacterial suspension were mixed and left in contact for 2 minutes at 30° C. 8 mL of the formulations described below in Table III were then added to the mixture and left in contact for 1 minute at 30° C. For the inoculum control, one milliliter of the resulting solution was removed and diluted with 9 mL of diluent at pH 7.0, and then four successive dilutions were made. Samples from each dilution were plated in duplicate and agar was added. For each treatment, one mL of the previous mixture was added to 9 mL of neutralizing solution and then mixed. One mL of the neutralized solution was then placed into petri dishes in duplicate. Approximately 15 mL of sterile tryptic soy agar was added to each Petri dish and when solidified, each plate was incubated at 36° C. for 48 hours. Colony forming units on plates were counted after 24 and 48 hours incubation. This procedure was repeated for all samples to be tested. Passing bactericidal efficacy is at least a 5-log reduction of starting inoculum cell counts.

[0076 According to a modified EN 1657 dilution neutralization method, yeast are exposed to an interfering substance before being exposed to the composition. The interfering substance was a mixture of 10 g/L bovine albumin and 10 g/L yeast extract (high soil), and 3 g/L bovine albumin (low soil), respectively. The microorganism used to evaluate disinfection was Candida albicans ATCC 10231 (C. albicans).

[0077] The microorganisms are prepared from glycerol stocks that are spread onto malt extract plates and allowed in incubate for 42-48 hours. This is the stock culture. A subculture is then prepared from the stock culture by streaking malt extract agar plates and allowing incubation for 42-72 hours. Second and third subcultures are prepared from the first subculture in the same way. These subcultures are the working cultures. Loopfuls of the working cultures are then transferred to diluent to create a standardized cell suspension, this suspension is used in the testing against the compositions. The yeasts were diluted to form a suspension having an initial concentration of about 10⁷ cfu/mL.

[0078] Standard general disinfection temperature is 10°C; however, 30°C is a more realistic teat disinfection temperature. All reagents used in the testing of the compositions are equilibrated to temperature before the testing begins. The standard contact time for general disinfection is 30 minutes; however, the practical contact time for pre-milking teat disinfection is 1 minute. To test the compositions from Table III, 1 mL of interfering substance and 1 mL of yeast extract were mixed and left in contact for 2 minutes at 30° C. 8 mL of the formulations described below in Table III were then added to the mixture and left in contact for 1 minute at 30° C. For the inoculum control, one milliliter of the resulting solution was removed and diluted with 9 mL of diluent at pH 7.0, and then three successive dilutions were made. Samples from each dilution were plated in duplicate and agar was added. For each treatment, one mL of the previous mixture was added to 9 mL of neutralizing solution and then mixed. One mL of the neutralized solution was then placed into petri dishes in duplicate. Approximately 15 mL of sterile tryptic soy agar was added to each Petri dish and when solidified, each plate was incubated at 30° C. for 48 hours. Colony forming units on plates were counted after 48 hours incubation. This procedure was repeated for all samples to be tested. Passing bactericidal efficacy is at least a 4-log reduction of starting inoculum cell counts.

[0079] The plates with microbial growth populations between 30 and 300 were counted and results were expressed as logarithmic reductions according to EN 1656 and EN 1657 test methods. Table III below provides the results of the EN 1656 and EN 1657 tests and the formulations tested under high soil conditions, and Table IV below provides the results of the EN 1656 and EN 1657 tests and the formulations tested under low soil conditions and contact time of 1 minute (formulations 44-46) and 30 seconds (formulations 47-52) respectively.

Table III Table IV [0080] The results from Table III and IV demonstrate several noteworthy trends. Yeasticidal efficacy appears to be influenced by several factors, namely the presence of salicylic acid, the quantity of glycolic acid, and the quantity of the anionic surfactant sodium lauryl sulfate (SLS). As can be seen in Formulations 33 and 34, when no salicylic acid is present, the formulations do not exhibit acceptable yeasticidal efficacy. And, although in Formulation 18, yeasticidal efficacy can be achieved in the absence of salicylic acid, this formulation requires at least 10% glycolic acid, which would render it quite irritating to animal skin, and the formulation does not exhibit passing low temperature stability. Further, as illustrated by Formulations 37-43, at least a certain minimal level of glycolic acid is required to support the yeasticidal efficacy of salicylic acidcontaining formulations under high soil conditions. For example formulation 41 has a 5.4 log reduction of C. albicans under high soil conditions. Also, as illustrated by formulations 14, 15, 27, and 35, at least a certain minimal level of SLS is required to support the yeasticidal efficacy of formulations comprising both salicylic and glycolic acids.

[0081 ] It was discovered, too, that salicylic acid as the only organic acid may not be sufficient to impart sufficient antibacterial characteristics. Formulations 20, 38, and 39 illustrate that when glycolic acid is absent, the formulations do not provide antibacterial efficacy for all tested species, even though some yeasticidal characteristics may be observed with relatively high levels of salicylic acid.

[0082] The results from Table III also demonstrate that low temperature stability is influenced by several factors. As illustrated by Formulations 21 and 22, too high of a SLS content appears to adversely affect low temperature stability. Also, the absence of salicylic acid coupled with high glycolic acid levels can also adversely affect low temperature stability as illustrated by Formulations 16-18.

[0083] Therefore, the data illustrated in Table III and Table IV establishes that the combination of glycolic acid, salicylic acid and an anionic alkyl sulfate surfactant achieve yeasticidal and bactericidal efficacy as well as cold temperature stability. DEFINITIONS

[0084] It should be understood that the following is not intended to be an exclusive list of defined terms. Other definitions may be provided in the foregoing description, such as, for example, when accompanying the use of a defined term in context.

[0085] As used herein, the terms “a,” “an,” and “the” mean one or more.

[0086] As used herein, the term “and/or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and/or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination, B and C in combination; or A, B, and C in combination.

[0087] As used herein, the terms “comprising,” “comprises,” and “comprise” are open-ended transition terms used to transition from a subject recited before the term to one or more elements recited after the term, where the element or elements listed after the transition term are not necessarily the only elements that make up the subject.

[0088] As used herein, the terms “having,” “has,” and “have” have the same open-ended meaning as “comprising,” “comprises,” and “comprise” provided above.

[0089] As used herein, the terms “including,” “include,” and “included” have the same open-ended meaning as “comprising,” “comprises,” and “comprise” provided above.

NUMERICAL RANGES

[0090] The present description uses numerical ranges to quantify certain parameters relating to the invention. It should be understood that when numerical ranges are provided, such ranges are to be construed as providing literal support for claim limitations that only recite the lower value of the range as well as claim limitations that only recite the upper value of the range. For example, a disclosed numerical range of 10 to 100 provides literal support for a claim reciting “greater than 10” (with no upper bounds) and a claim reciting “less than 100” (with no lower bounds). CLAIMS NOT LIMITED TO DISCLOSED EMBODIMENTS

[0091] The preferred forms of the invention described above are to be used as illustration only and should not be used in a limiting sense to interpret the scope of the present invention. Modifications to the exemplary embodiments, set forth above, could be readily made by those skilled in the art without departing from the spirit of the present invention.

[0092] The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of the present invention as it pertains to any apparatus not materially departing from but outside the literal scope of the invention as set forth in the following claims.

Claims

1. An antimicrobial composition comprising: salicylic acid; glycolic acid; and at least one anionic surfactant comprising an alkyl sulfate.

2. The composition according to claim 1 , wherein the composition comprises at least one anionic surfactant comprising sodium lauryl sulfate (SLS).

3. The composition according to claim 2, wherein the composition comprises from 0.15% to 0.6% by weight of salicylic acid, from 0.5% to 10% by weight of glycolic acid, and from 0.3% to 2% of SLS.

4. The composition according to any of claims 1 -3, wherein the composition further comprises from 0.5% to 10% of a freezing point depressant compound, and from 0.02% to 1 % of magnesium oxide.

5. The composition according to claim 4, wherein the freezing point depressant compound is propylene glycol.

6. The composition according to any of claims 1 -5, wherein the composition further comprises at least one additional anionic surfactant selected from the group consisting of a-olefin sulfonates and alkyl sulfonates.

7. The composition according to claim 6, wherein the at least one additional anionic surfactant comprises a Cu-C sodium a-olefin sulfonate and a sodium octane sulfonate.

8. The composition according to any of claims 1 -7, wherein the composition is storage stable for at least one month at 4°C.

9. The composition according to any of claims 1-8, wherein the composition further includes at least one non-ionic surfactant comprising an alcohol ethoxylate.

10. An antimicrobial teat dip composition for use in the control or prevention of bovine mastitis when contacted with the teats of a cow comprising: salicylic acid; glycolic acid; and at least one anionic surfactant.

11 . The antimicrobial teat dip composition for use according to claim 10, wherein the at least one anionic surfactant comprises sodium lauryl sulfate (SLS).

12. The antimicrobial teat dip composition for use according to claim 11 , wherein the composition comprises from 0.15% to 0.6% by weight of salicylic acid, from 0.5% to 10% by weight of glycolic acid, and from 0.3% to 2% SLS.

13. The antimicrobial teat dip composition for use according to any of claims 10-12, wherein the composition further comprises from 0.5% to 10% of propylene glycol and from 0.02% to 1 % of magnesium oxide.

14. The antimicrobial teat dip composition for use according to any of claims 10-13, wherein the composition further comprises at least one additional anionic surfactant selected from the group consisting of a-olefin sulfonates and alkyl sulfonates.

15. The antimicrobial teat dip composition for use according to any of claims 10-14, wherein the composition further includes at least one non-ionic surfactant comprising an alcohol ethoxylate.