THE SAME

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to U.S. Provisional Application No. 63/157100, filed on March 5, 2021.

TECHNICAL FIELD

[0002] This disclosure relates to disinfectant compositions useful in institutional and healthcare applications.

BACKGROUND

[0003] Conventional antimicrobial compositions typically used in liquid disinfectant often present limitations in reaching antimicrobial efficacies at the permitted levels. In addition, many of the compositions pose formulation stability challenges, especially when the concentrations of active ingredients are increased in order to achieve higher antimicrobial efficacy. This may result in unsatisfactory shelf life of the disinfectant compositions, as well as potential hazards under regular storage and use conditions. Some conventional liquid disinfectants purportedly contain both antimicrobial efficacy and biodegradability by using plant origin raw materials. These products, however, do not meet the expectations for desired product attributes (such as foaming profile) observed in commercial non-green, synthetic compositions. Further, biodegradable and plant origin raw materials often produce negative olfactory aspects (such as unpleasant odor) in conventional disinfectant products, causing unsatisfactory user experience and reducing the actual use of these products.

[0004] There is still a need for disinfectant compositions with enhanced antimicrobial efficacy.

SUMMARY

[0005] In one aspect, a synergistic disinfectant composition is provided that comprises about 0.1% to about 40.0% by weight of acid component, and from about 0.1% to about 40.0% by weight of anionic surfactant based on total weight of the disinfectant composition. The acid component comprises a first acid having pKa of less than 4, and a second acid having logP of greater than 2. In some embodiments, the first acid fulfills at least one of the following: (a) the first acid has pKa of less than 4, (b) the first acid has pKa of greater than 2.5 but less than 4, (c) the first acid has pKa of greater than 2.5 but less than 4, and logP of less than 2; and/or the second acid fulfills at least one of the following: (i) the second acid has logP of greater than 2, (ii) the second acid has pKa of greater than 2.5 and logP of greater than 2. Optionally, the disinfectant composition may comprise an oxidizing agent, such as hydrogen peroxide.

[0006] In another aspect, a method of disinfecting a surface is provided that comprises contacting the surface with the aforementioned synergistic disinfectant composition.

[0007] Other aspects of the disclosure will become apparent by consideration of the detailed description.

DETAILED DESCRIPTION

[0008] The present disclosure generally relates to a synergistic disinfectant composition, in which the antimicrobial efficacy is enhanced through the unexpected synergy between a first acid having pKa of less than 4 and a second acid having logP of greater than 2. In some embodiments, the first acid fulfills at least one of the following: (a) the first acid has pKa of less than 4, (b) the first acid has pKa of greater than 2.5 but less than 4, (c) the first acid has pKa of greater than 2.5 but less than 4, and logP of less than 2; and/or the second acid fulfills at least one of the following: (i) the second acid has logP of greater than 2, (ii) the second acid has pKa of greater than 2.5 and logP of greater than 2

[0009] The terms “comprise(s),” “comprising,” “include(s),” “including,” “having,” “has,” “contain(s),” “containing,” and variants thereof, as used herein, are open-ended transitional phrases, terms, or words that are meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The singular forms “a", “and”, and “the” include plural references unless the context clearly dictates otherwise. Where the term “comprising” is used, the present disclosure also contemplates other embodiments “comprising”, “consisting of, or “consisting essentially of elements presented herein, whether explicitly set forth or not.

[0010] Any numerical range recited herein includes all values from the lower value to the upper value. For example, if a concentration range is stated as 1% to 50%, it is intended that values such as 2% to 40%, 10% to 30%, or 1% to 3%, etc., are expressly enumerated in this specification. These are only examples of what is specifically intended, and all possible combinations of numerical values between and including the lowest value and the highest value enumerated are to be considered to be expressly stated in this application.

[0011] The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (for example, it includes at least the degree of error associated with the measurement of the particular quantity). The term “about” refers to plus or minus 10% of the indicated number. For example, “about 10%” indicates a range of 9% to 11%, and “about 1” means from 0.9 to 1.1. Other meanings of “about” may be apparent from the context, such as rounding off, so, for example “about 1” means from 0.5 to 1.4. The modifier “about” should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression “from about 2 to about 4” also discloses the range “from 2 to 4.”

[0012] The terms "weight percent," "wt%," "percent by weight," "% by weight," and variations thereof, as used herein, refer to the concentration of a component as the weight of that component divided by the total weight of the composition and multiplied by 100. Unless indicated otherwise, all concentrations are expressed as weight percentage concentrations.

[0013] The term “effective amount” refers to an amount effective that would achieve a desired effect or result. For example, an effective amount of a disinfectant composition may refer to the amount of such composition to achieve a level of antimicrobial activity, which can be measured with a standardized test known in the art. An effective amount of a disinfectant composition may be determined by known methods and may vary according to factors such as the microbial strains, test media, temperature, and other conditions.

[0014] The term “pKa”, as used herein, refers to a value known in the art to indicate the strength of an acid. pKa is a negative log value of the acid dissociation constant (Ka), which is an equilibrium constant of the acid dissolution in aqueous solution. A lower pKa value indicates a stronger acid, i.e., such acid more fully dissociates in water. The pKa value, as used herein, is the pKa value of acid at room temperature (about 20°C to about 25°C).

[0015] The term “LogP”, as used herein, refers to a value known in the art to indicate the lipophilicity of a substance. LogP is the logarithm of P, which is a partition coefficient of the substance between n-octanol and water. A higher LogP value indicates a higher !ipophiiicity. The LogP value, as used herein, is the LogP value of substance at room temperature (about 20°C to about 25°C).

[0016] The term “substantially free", "free", "substantially no", or "no" refers to a disinfectant composition that does not contain a particular compound, or to which a particular compound has not been added to the disinfectant composition. Should the particular compound be present through contamination, the amount of such particular compound shall be less than 0.5% by weight, preferably less than 0.1% by weight.

[0017] The term “disinfectant", as used herein, refers to an antimicrobial composition that is capable of kiiiing, removing, destrueting, controliing, and/or reducing at least portion of microorganisms. Disinfectant may include, but is not limited to, sanitizer, bacteriostatic, mildew static, sterilant, or any other antimicrobials.

[0018] The disclosed disinfectant composition may comprise an acid component, an anionic surfactant, and optionally an oxidizing agent.

[0019] Acid Component

[0020] The acid component comprises a first acid having pKa of less than 4, and a second acid having logP of greater than 2.

[0021] In some embodiments, the acid component comprises the first acid having pKa of greater than 2.5 but less than 4, and the second acid having logP of greater than 2.

[0022] In some embodiments, the acid component comprises the first acid having pKa of greater than 2.5 but less than 4, and logP of less than 2; and the second acid having pKa of greater than 2.5 and logP of greater than 2.

[0023] In some embodiments, the acid component comprises the first acid that fulfills at least one of the following:

(a) the first acid having pKa of less than 4,

(b) the first acid having pKa of greater than 2.5 but less than 4,

(c) the first acid having pKa of greater than 2.5 but less than 4, and logP of less than 2; and/or the second acid that fulfills at least one of the following:

(i) a second acid having logP of greater than 2,

(ii) the second acid having pKa of greater than 2.5 and logP of greater than 2. [0024] Examples of the first acid having pKa of less than 4 include, but are not limited to, ethane sulfonic acid (pKa of -1.68), methane sulfonic acid (pKa of -1 .9), oxalic acid (pKa of 1.25), etidronic acid (pKa of 1.35), phosphoric acid (pKa of 2.16), 2-hydroxybenzoic acid (pKa of 2.97), citric acid (pKa of 3.13), furoic acid (pKa of 3.21), gluconic acid (pKa of 3.6), formic acid (pKa of 3.75), glycolic acid (pKa of 3.83), lactic acid (pKa of 3.86).

[0025] Examples of the second acid having logP of greater than 2 include, but are not limited to, 2-hydroxybenzoic acid (log P of 2.26), 2-ethyl hexanoic acid (log P of 2.64), 2-propylpentanoic acid (log P of 2.75), 2-propylhexanoic acid (log P of 3.01), octanoic acid (log P of 3.05), 2-propyl heptanoic acid (log P of 3.2), nonanoic add (log P of 3.42), decanoic acid (log P of 4.09), and dodecanoic acid (log P of 4.6).

[0026] In some embodiments, the first acid comprises phosphoric acid, and the second acid comprises fatty acid containing at least 8 carbon atoms such as octanoic acid or decanoic acid. In some embodiments, the first acid comprises furoic acid, and the second acid comprises fatty acid containing at least 8 carbon atoms such as octanoic acid or decanoic acid. In some embodiments, the first acid comprises furoic acid, and the second acid comprises substituted benzoic acid having LogP of more than 2 (e.g., 2-hydroxybenzolic acid or 3,4,5-trichlorobenzoic acid).

[0027] The disinfectant compositions disclosed herein may comprise from about 0.1% to about 40.0% by weight of the acid component. The compositions may comprise at least 0.1%, at least 0.3%, at least 0.5%, at least 1.0%, at least 2.0%, at least 3.0%, at least 4.0%, at least 5.0%, at least 6.0%, at least 7.0%, at least 8.0%, at least 9.0%, at least 10.0%, at least 12.0%, at least 15.0%, at least 20.0%, at least 30.0%, or at least 40.0% by weight of the acid component; and/or the compositions may comprise less than 40.0%, less than 30.0%, less than 25.0%, less than 20.0%, less than 15.0%, less than 12.0%, less than 10.0%, less than 9.0%, less than 8.0%, less than 7.0%, less than 6.0%, less than 5.0%, less than 4.0%, less than 3.0%, less than 2.0%, or less than 1.0% by weight of the acid component.

[0028] For example, the compositions may comprise from about 0.1% to about 40.0%, from about 0.1% to about 30.0%, from about 0.1% to about 25.0%, from about 0.1% to about 20.0%, from about 0.1% to about 15.0%, from about 0.1% to about 10.0%, or from about 0.1% to about 5.0% by weight of the acid component. The compositions may comprise from about 0.5% to about 40.0%, from about 0.5% to about 30.0%, from about 0.5% to about 25.0%, from about 0.5% to about 20.0%, from about 0.5% to about 15.0%, from about 0.5% to about 10.0%, or from about 0.5% to about 5.0% by weight of the acid component. The compositions may comprise from about 1.0% to about 40.0%, from about 1.0% to about 30.0%, from about 1.0% to about 25.0%, from about 1.0% to about 20.0%, from about 1.0% to about 15.0%, from about 1.0% to about 12.0%, from about 1.0% to about 10.0%, from about 1.0% to about 8.0%, from about 1.0% to about 6.0%, or from about 1.0% to about 5.0% by weight of the acid component. In some embodiments, the compositions comprise from about 1.0% to about 25.0% by weight of the acid component. In particular embodiments, the compositions comprise from about 0.5% to about 15.0% by weight, or from about 1.0% to about 12.0% by weight of the acid component.

[0029] In some embodiments, the composition comprises from about 0.05% to about 20% by weight of the first acid, and from about 0.05% to about 20% by weight of the second acid based on total weight of the composition.

[0030] In some embodiments, the acid component comprises:

(a) at least 0.05%, at least 0.1 %, at least 0.2%, at least 0.5%, at least 1.0%, at least 2.0%, at least 3.0%, at least 4.0%, at least 5.0%, at least 6.0%, at least 7.0%, at least 8.0%, at least 9.0%, at least 10.0%, at least 11.0%, at least 12.0%, at least 13.0%, at least 14.0%, or at least 15.0% by weight of the first acid; and/or less than 20.0%, less than 15.0%, less than 14.0%, less than 13.0%, less than 12.0%, less than 11.0%, less than 10%, less than 9.0%, less than 8.0%, less than 7.0%, less than 6.0%, less than 5.0%, less than 4.0%, less than 3.0%, less than 2.0%, less than 1.0%, or less than 0.5% by weight of the first acid;

(b) at least 0.05%, at least 0.1 %, at least 0.2%, at least 0.5%, at least 1.0%, at least 2.0%, at least 3.0%, at least 4.0%, at least 5.0%, at least 6.0%, at least 7.0%, at least 8.0%, at least 9.0%, at least 10.0%, at least 11.0%, at least 12.0%, at least 13.0%, at least 14.0%, or at least 15.0% by weight of the second acid; and/or less than 20.0%, less than 15.0%, less than 14.0%, less than 13.0%, less than 12.0%, less than 11.0%, less than 10%, less than 9.0%, less than 8.0%, less than 7.0%, less than 6.0%, less than 5.0%, less than 4.0%, less than 3.0%, less than 2.0%, less than 1.0%, or less than 0.5% by weight of the second acid.

[0031] Anionic Surfactant

[0032] Suitable anionic surfactants for use in the compositions may include, but are not limited to, amino acid based surfactant, sulfate surfactant, sulfonate surfactant, carboxylate surfactant, phosphate surfactant, sulfosuccinate surfactant, or such surfactants listed above in acidified or protonated forms.

[0033] The term “amino acid based surfactant” as used herein refers to a chemical compound derived from a natural or synthetic amino acid molecule and having surfactant properties. The amino acid based surfactants include fatty acid derivatives of amino acids, or salts thereof, in which a fatty acid is attached to the amino acid through condensation of a carboxy group (-COOH) of the fatty acid and an amino group (-NH2) of the amino acid to form an amide bond (-CONH-). Suitable amino acids may include, but are not limited to, glycine, lysine, sarcosine, glutamic acid, aspartic acid, aminomalonic acid, or any combination thereof. Suitable fatty acids may include a C10-24 fatty acid, such as C12-20 or C12-18 fatty acids.

[0034] The term “C10-24 fatty acid” as used herein refers to a carboxylic acids having 10 to 24 carbon atoms. The carboxylic acid may have from 0 to 24 carbon- carbon double bonds. The carboxylic acid may have a straight or branched carbon chain, a cyclic carbon ring, or an aromatic carbon ring. The carboxylic acid may be unsubstituted or substituted with one or more substituent groups, each of which independently selected from hydroxy (-OH), amino, cyano, halogen, thiol, oxo (=0), and thioxo (=S). Examples of suitable C10-24 fatty acids may include, but are not limited to, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, myristoleic acid, oleic aicd, linoleic acid, erucic acid, docosahexaenoic acid, or any combination thereof.

[0035] In some embodiments, the amino acid based surfactant may comprise a C10-24 fatty acid derivative of amino acid. In some further embodiments, the amino acid based surfactant may comprise a C10-24 fatty acid derivative of amino acid, wherein the amino acid comprises glycine, sarcosine, glutamic acid, aspartic acid, aminomalonic acid, or combinations thereof.

[0036] Suitable amino acid based surfactants may include, but are not limited to, sodium lauroyl sarcosinate, sodium lauroyl glycinate, sodium lauroyl aminomalonate, sodium lauroyl aspartate, sodium N-lauroylglutamate, sodium cocoyl glutamate, or combinations thereof. Commercial examples of amino acid based surfactants include sarcosinates marketed under the tradenames Perlastan® (Schill+Seilacher GmbH), Maprosyl® (Stepan Company, USA), Crodasinic® (Croda, UK), Oramix® (Seppic, France), and acylglutamate products, marketed as Amisoft® (Ajinomoto Corp., Japan). [0037] Non-limiting examples of sulfate surfactants include alkyl sulfates (e.g, sodium or ammonium salts of C12-14 alcohol sulfate); alkyl ether sulfates (e.g., sodium laureth sulfate; sodium or ammonium salts of C12-14 alcohol ethoxylate sulfate).

[0038] Non-limiting examples of sulfonate or sulfonic acid surfactants include C8-C22 alkyl sulfonate; alkyl aryl sulfonates (e.g., dodecyi benzene sulfonate, linear alkyl benzene sulfonic acid); alpha-olefin sulfonates; alkyl glyceryl sulfonates; alkyl taurates; acyl taurates; sulfoacetates (e.g., sodium lauryl sulfoacetate); C8-C22 alkyl sulfonic acid; alkyl benzene sulfonic acid (e.g. dodecylbenzenesulfonic acid, linear alkylbenzene sulfonic acid);

[0039] Non-limiting examples of sulfosuccinate surfactants include alkyl sulfosuccinates such as disodium laureth sulfosuccinate, sodium dioctyl sulfosuccinate. Non-limiting examples of carboxylate surfactants include succinates (e.g. monostearyl succinate); monoalkyl maleates; acyl isethionates; alkyl carboxylates; alkyl ether carboxylates. Non-limiting examples of phosphate surfactants include alkyl phosphates, silicone phosphates, phosphate esters.

[0040] Furthermore, without limitation, suitable anionic surfactants may include sodium lauryl sulfate, sodium lauryl ether sulfate, ammonium lauryl sulfosuccinate, ammonium lauryl sulfate, ammonium lauryl ether sulfate, sodium dodecylbenzene sulfonate, triethanolamine dodecylbenzene sulfonate, sodium cocoyl isethionate, sodium lauroyl isethionate, or any combination thereof.

[0041] The disclosed disinfectant compositions may comprise from about 0.1% to about 40.0% by weight of the anionic surfactant based on total weight of the composition.

[0042] The compositions may comprise at least 0.1%, at least 0.2%, at least 0.4%, at least 0.6%, at least 0.8%, at least 1.0%, at least 2.0%, at least 2.5%, at least 3.0%, at least 3.5%, at least 4.0%, at least 4.5%, at least 5.0%, at least 6.0%, at least 7.0%, at least 8.0%, at least 9.0%, at least 10.0%, at least 12.0%, at least 15.0%, at least 20.0%, or at least 25.0% by weight of the anionic surfactant; and/or the compositions may comprise less than 40.0%, less than 30.0%, less than 25.0%, less than 20.0%, less than 15.0%, less than 12.0%, less than 10.0%, less than 9.0%, less than 8.0%, less than 7.0%, less than 6.0%, less than 5.0%, less than 4.5%, less than 4.0%, less than 3.5%, less than 3.0%, less than 2.5%, less than 2.0%, less than 1.5%, less than 1.0%, less than 0.8%, less than 0.6%, less than 0.4 %, or less than 0.2% by weight of the anionic surfactant.

[0043] For example, the compositions may comprise from about 0.1% to about 30.0%, from about 0.1% to about 25.0%, from about 0.1% to about 20.0%, from about 0.1% to about 15.0%, from about 0.1% to about 10.0%, from about 0.1 to about 8.0%, from about 0.1 % to about 6.0%, from about 0.1% to about 5.0%, from about 0.1% to about 4.0%, from about 0.1% to about 3.0%, from about 0.1% to about 2.0%, or from about 0.1% to about 1.0% by weight of the anionic surfactant. In some embodiments, the compositions comprise from about 0.1% to about 20.0% by weight of the anionic surfactant. In particular embodiments, the compositions comprise from about 0.2% to about 10.0% by weight, or from about 0.2% to about 6.0% by weight of the anionic surfactant.

[0044] Oxidizing Agent

[0045] The compositions disclosed herein may optionally include an oxidizing agent. Suitable oxidizing agents may include, for example, hydrogen peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, tert-butyl hydroperoxide, cumene hydroperoxide, tertamyl hydroperoxide, tert-butylperpivalate, tert-butyl perbenzoate, benzoyl peroxide, peroxyacids (like peracetic acid), ozone, chlorine dioxide, or any combination thereof. In some embodiments, the oxidizing agent may be a peroxide such as hydrogen peroxide.

[0046] The compositions may comprise at least 0.01%, at least 0.05%, at least 0.1%, at least 0.2%, at least 0.3%, at least 0.4%, at least 0.5%, at least 1.0 %, at least 2.0%, at least 3.0%, or at least 4.0% by weight of the oxidizing agent; and/or the compositions may comprise less than 9.0%, less than 8.0%, less than 7.0%, less than 6.0%, less than 5.0%, less than 4.0%, less than 3.0%, less than 2.0%, less than 1 .5%, less than 1.0%, less than 0.5%, less than 0.4%, less than 0.3%, less than 0.2%, or less than 0.1% by weight of the oxidizing agent based on total weight of the composition.

[0047] For example, the compositions may comprise from about 0.01% to about 8.0%, about 0.01% to about 7.0%, about 0.01% to about 6.0%, about 0.01% to about 5.0%, from about 0.01% to about 4.0%, from about 0.01% to about 3.0%, from about 0.01% to about 2.0%, from about 0.01 % to about 1.5%, from about 0.01% to about 1.0%, from about 0.01% to about 0.5%, from about 0.01% to about 0.4%, from about 0.01% to about 0.3%, from about 0.01% to about 0.2%, or from about 0.01% to about 0.1% by weight of the oxidizing agent. In some embodiments, the compositions comprise from about 0.01% to about 1.5% by weight, or from about 0.5% to about 1 .5% by weight of the oxidizing agent based on total weight of the composition.

[0048] In some embodiments, the composition comprises an oxidizing agent and the oxidizing agent is peroxide, which is present in an amount of from about 0.5% to about 1.5% by weight based on total weight of the composition.

[0049] In some embodiments, the composition comprises a peroxide oxidizing agent in an amount of at least 0.01%, at least 0.05%, at least 0.1%, at least 0.2%, at least 0.3%, at least 0.4%, at least 0.5%, at least 1.0 %, at least 2.0%, at least 3.0%, or at least 4.0% by weight of the oxidizing agent; and/or the composition comprise less than 9.0%, less than 8.0%, less than 7.0%, less than 6.0%, less than 5.0%, less than 4.0%, less than 3.0%, less than 2.0%, less than 1.5%, less than 1.0%, less than 0.5%, less than 0.4%, less than 0.3%, less than 0.2%, or less than 0.1% by weight of the peroxide oxidizing agent based on total weight of the composition.

[0050] In some embodiments, the composition comprises a peroxide oxidizing agent in an amount of from about 0.01% to about 8.0%, about 0.01% to about 7.0%, about 0.01% to about 6.0%, about 0.01% to about 5.0%, from about 0.01% to about 4.0%, from about 0.01 % to about 3.0%, from about 0.01% to about 2.0%, from about 0.01% to about 1.5%, from about 0.01% to about 1.0%, from about 0.01% to about 0.5%, from about 0.01 % to about 0.4%, from about 0.01% to about 0.3%, from about 0.01% to about 0.2%, or from about 0.01% to about 0.1% by weight of the oxidizing agent. In some embodiments, the compositions comprise from about 0.01% to about 1 .5% by weight, or from about 0.5% to about 1.5% by weight of the oxidizing agent based on total weight of the composition.

[0051] In some embodiments, the composition is substantially free of any oxidizing agent. In some embodiments, the composition includes the oxidizing agent in an amount of less than 0.005%, less than 0.001%, less than 0.0005%, or less than 0.0001% by weight based on total weight of the composition.

[0052] Organic Solvent

[0053] The compositions disclosed herein may optionally include organic solvent. Suitable organic solvents may include, but are not limited to, C1-8 alcohol, glycerol, polyhydric alcohol, polyol, glycol ether, or any combination thereof.

[0054] Non-limiting examples of the C1-8 alcohols include methanol, ethanol, propanol, isopropanol, 1-butanol, 1-pentanol, 2-pentanol, 1-hexanol, 2-hexanol, benzyl alcohol, or any combination thereof. Non-limiting examples of the polyhydric alcohols include ethylene glycol, propylene glycol, dipropylene glycol, glycerin, 1,2- butanediol, 1 ,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1 ,2-propanediol, 1,5- pentanediol, meso-erythritol, neopentyl glycol, pentaerythritol, or any combination thereof. Non-limiting examples of the polyols include alkane polyols having from 2-6 carbon atoms and from 2-3 hydroxyls in the molecule. Non-limting examples of the glycol ethers include, but are not limited to, those based on ethylene or propylene glycol (e.g., diethylene glycol ethyl ether, dipropylene glycol methyl ether, diethylene glycol methyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, ethylene/diethylene glycol 2-ethylhexyl ether, ethylene glycol phenyl ether, dipropylene glycol propyl ether, dipropylene glycol butyl ether, propylene glycol phenyl ether), or any combination thereof.

[0055] The compositions may comprise at least 0.05%, at least 0.1 %, at least 0.2%, at least 0.5%, at least 1 .0%, at least 2.0%, at least 3.0%, at least 4.0%, at least 5.0%, at least 6.0%, at least 7.0%, at least 8.0%, at least 9.0%, at least 10.0%, at least 12.0%, at least 15.0%, at least 20.0%, or at least 25.0% by weight of the organic solvent; and/or the compositions may comprise less than 80.0%, less than 70.0%, less than 60.0%, less than 50.0%, less than 40.0%, less than 30.0%, less than 20.0%, less than 15.0%, less than 12.0%, less than 10.0%, less than 9.0%, less than 8.0%, less than 7.0%, less than 6.0%, less than 5.0%, less than 4.0%, less than 3.0%, less than 2.0%, less than 1.0%, less than 0.5%, less than 0.2%, or less than 0.1% by weight of the organic solvent.

[0056] In some embodiments, the composition may comprise from about 0.05% to about 70.0%, from about 0.05% to about 60.0%, from about 0.05% to about 50.0%, from about 0.05% to about 40.0%, from about 0.05% to about 30.0%, from about 0.05% to about 25.0%, from about 0.05% to about 20.0%, from about 0.05% to about 15.0%, from about 0.05% to about 10.0%, from about 0.05% to about 8.0%, from about 0.05% to about 6.0%, from about 0.05% to about 4.0%, from about 0.05% to about 2.0%, or from about 0.05% to about 1 .0% by weight of the organic solvent. In some embodiments, the compositions comprise from about 0.1% to about 20.0% by weight of the organic solvent. In particular embodiments, the compositions comprise from about 1.0% to about 10.0% by weight, or from about 1.0% to about 6.0% by weight of the organic solvent. [0057] Nonionic Surfactant

[0058] The compositions disclosed herein may optionally include nonionic surfactant. Suitable nonionic surfactants may include, but are not limited to, alkylene glycol; polyalkylene glycol; alcohol ethoxylate (e.g., fatty alcohol ethoxylates); ethoxylate of alkyl polyethylene glycol ether; ethylene oxide adduct (e.g., ethylene oxide adduct of C8 to C22, preferably C8 to C16, more preferably C8 to C12 alcohol); ethylene oxide/ propylene oxide adduct (e.g., alkoxylated nonionic surfactant having an EO/PO block copolymer); alkyl phenol ethoxylate; alkyl polyglucoside, or any combination thereof. Non-limiting examples of suitable types of non-ionic surfactant include ethoxylates of alkyl polyethylene glycol ethers, polyalkylene glycol (e.g., 100% Breox FCC92), or alcohol alkoxylate EO/PO (e.g., Plurafac LF403). Exemplary alcohol ethoxylates include fatty alcohol ethoxylates, e.g., tridecyl alcohol alkoxylate, ethylene oxide adduct, alkyl phenol ethoxylates, or ethoxy/propoxy block surfactants. In some embodiments, the nonionic surfactant is alcohol ethoxylates, EO/PO block copolymers, alkyl polyglucosides, or any combination thereof.

[0059] Additonal Ingredients

[0060] The disclosed composition may further include an effective amount of one or more additional ingredients selected from pH adjusting agents, buffering agents, hydrotropes, corrosion inhibitors, sequestering agents, antimicrobial compounds, dyes, rheology modifiers, preservatives, moisturizing agents, emollients, or any combination thereof. The compositions may comprise from about 0.01% to about 8.0%, from about 0.01% to about 7.0%, from about 0.01% to about 6.0%, from about 0.01% to about 5.0%, from about 0.01% to about 4.0%, from about 0.01% to about 3.0%, from about 0.01% to about 2.0%, from about 0.01% to about 1.0%, from about 0.01 % to about 0.5%, or from about 0.01 % to about 0.1 % by weight each of one or more of the additional ingredients.

[0061] In some embodiments, the compositions as disclosed herein have a pH of 5 or less, preferably from about 1.0 to about 3.0. The compositions may have a pH value of less than 4.5, less than 4.0, less than 3.5, less than 3.0, less than 2.5, less than 2.0, less than 1.5, or even less than 1.0; and/or the compositions may have a pH value of at least 0.1 , at least 0.5, at least 1.0, at least 1.5, at least 2.0, at least 2.5, at least 3.0, at least 3.5, at least 4.0, or at least 4.5. In some embodiments, the pH is about 1.0 to about 3.0, including about 1.5 to about 3.0, about 2.0 to 3.0, about 2.1 to 3.0, about 2.2 to 3.0, about 2.2 to 3.0, about 2.3 to 3.0, about 2.4 to 3.0, or about 2.5 to 3.0. In particular embodiments, the pH is about 2.0 to about 3.0, including about 2.1 to about 2.9, about 2.2 to 2.8, or about 2.3 to 2.8.

[0062] Suitable pH adjusting agents include substances demonstrating an alkaline property or substances demonstrating an acidic property. Examples of substances demonstrating an alkaline property include, but are not limited to, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; carbonates such as sodium carbonate, sodium bicarbonate, and potassium carbonate; silicates such as sodium silicate and potassium silicate; borates such as sodium borate; organic acid salts such as sodium citrate; amines such as monoethanolamine and diethanolamine, and ammonia. Examples of substances that demonstrate an acidic property and used for pH adjustment include, but are not limited to, inorganic acids such as hydrochloric acid and sulfuric acid, or organic acids such as citric acid and acetic acid.

[0063] Suitable buffering agents may include, but are not limited to, phosphoric acid, monosodium phosphate, disodium phosphate, trisodium phosphate, citric acid and salts such as sodium citrate, benzoic acid, sodium benzoate, or any combination thereof.

[0064] Suitable hydrotropes may include, but are not limited to, benzene sulfonates, naphthalene sulfonates, alkyl benzene sulfonates, naphthalene sulfonates, alkyl sulfonates, alkyl sulfates, alkyl diphenyloxide disulfonates, or phosphate ester hydrotropes. Exemplary alkyl benzene sulfonates include, for example, isopropylbenzene sulfonates, xylene sulfonates, toluene sulfonates, cumene sulfonates, or mixtures any two or more thereof. Exemplary alkyl sulfonates include hexyl sulfonates, octyl sulfonates, and hexyl/octyl sulfonates, or mixtures of any two or more thereof. In some embodiments, the hydrotrope comprises sodium xylene sulfonate, sodium cumene sulfonate, or combinations thereof.

[0065] Suitable corrosion inhibitors may include, but are not limited to, triazoles such as benzotriazole, tolyltriazole, and mercaptobenzothiazole; gluconate salts such as sodium gluconate, potassium gluconate and ammonium gluconate; molybdate salts such as sodium molybdate, or any combination thereof.

[0066] Suitable sequestering agents may include, but are not limited to, various known phosphate and non-phosphate builder materials. Non-limiting examples of suitable non-phosphate agents include alkali metal citrates; carbonates; bicarbonates; the salts of nitrilotriacetic acid (NTA), methylglycine diacetic acid (MGDA), or glutaric diacetic acid (GLDA); polycarboxylates such as polymaleates, polyacetates, polyhydroxyacrylates, polyacrylate/polymaleate and polyacrylate/ polymethacrylate copolymers; zeolites, layered silica; or mixtures thereof. In some embodiments, the sequestering agent is selected from phosphates, NTA, EDTA, MGDA, GLDA, citrates, carbonates, bicarbonates, polyacrylate/polymaleate, or maleic anhydride/(meth)acrylic acid copolymers, e.g., Sokalan CP5 available from BASF.

[0067] The sequestering agent herein may also include anti-sealants, such as polyacrylates of molecular weight from 1 ,000 to 400,000, examples of which are supplied by Rohm & Haas, BASF and Alco Corp., or polymers based on acrylic acid combined with other moieties. These include acrylic acid combined with maleic acid, such as Sokalan CP5 and CP7 supplied by BASF or Acusol 479N supplied by Rohm & Haas with methacrylic acid such as Colloid 226/35 supplied by Rhone-Poulenc; with phosphonate such as Casi 773 supplied by Buckman Laboratories; with maleic acid and vinyl acetate such as polymers supplied by Huls; with acrylamide; with sulfophenol methallyl ether such as Aquatreat AR 540 supplied by Alco; with 2-acrylamido-2- methylpropane sulfonic acid such as Acumer 3100 supplied by Rohm & Haas or such as K-775 supplied by Goodrich; with 2-acrylamido-2-methylpropane sulfonic acid and sodium styrene sulfonate such as K-798 supplied by Goodrich; with methyl methacrylate, sodium methallyl sulfonate and sulfophenol methallyl ether such as Alcosperse 240 supplied by Alco; polymaleates such as Belclene 200 supplied by FMC; polymethacrylates such as Tamol 850 from Rohm & Haas polyaspartates; ethylenediamine disuccinate; or organo polyphosphonic acids and their salts such as the sodium salts of aminotri(methylenephosphonic acid) and ethane-1 -hydroxy-1 , 1- diphosphonic acid. In some embodiments, the sequestering agent may be phosphate, phosphonates, EDTA, MGDA, GLDA, polyacrylates, or any combination thereof.

[0068] Suitable antimicrobial compounds may include agents that can kill or otherwise inhibit the growth or proliferation of microbes including, for example, bacteria, viruses or fungi. Examples of antimicrobial compounds include, but are not limited to, quaternary ammonium salts, essential oils, antimicrobial pesticides, antibacterials, antivirals, or antiparasitics known in the art.

[0069] The compositions may contain dyes used in disinfectant products to visualize coverage or pH sensitive dyes such as thymolphthalein, bromothyol blue, and phenol phenolphthalein. [0070] Suitable rheology modifiers may include, but are not limited to, water soluble cellulosic polymers such as hydroxyethyl cellulose or hydroxypropyl cellulose.

[0071] Preservatives may include, but are not limited to, antimicrobials, biocides, or salts. For example, preservatives may include, but are not limited to, KATHON™ Preservatives (mixtures including methylchloroisothiazolinone and methylisothiazolinone from Dow Chemical, Midland, Mich.); NEOLONE 950™ (methylisothiazolinone from Dow Chemical, Midland, Mich.); DMDM hydantoin (available as GLYDANT™ from Lonza, Allendale, N.J.); iodopropynyl butylcarbamate; formaldehyde; benzoic esters (parabens), such as methyl paraben, propylparaben, butylparaben, ethylparaben, isopropylparaben, isobutylparaben, benzylparaben; 2- bromo-2-nitropropane-1,3-diol; benzoic acid; formic acid; or those known to those skilled in the art.

[0072] The disclosed disinfectant compositions may include at least one skin conditioner such as an emollient, humectant, occlusive agent, or other moisturizing agent to provide moisturizing, skin softening, skin barrier maintenance, anti-irritation, or other skin health benefits. Some non-limiting examples of emollients include stearoxytrimethylsilane, alkyl benzoate, silicone oils, dimethicone, myristyl myristate, cetyl myristate, glyceryl dioleate, methyl laurate, PPG-9 laurate, octyl palmitate, lanolin, propylene glycol, glycerol, fatty acids, natural oils such as sunflower, almond, mineral, canola, sesame, soybean, wheat germ, corn, peanut and olive, isopropyl myristate, myristyl alcohol, aloe vera, hydrolyzed silk protein, Vitamin E, stearyl alcohol, isopropyl palmitate, sorbitol, amino acid complexes, or polyethylene glycol. Some nonlimiting examples of humectants include hydroxyethyl urea, agarose, arginine PCA, fructose, glucose, glutamic acid, glycerol, honey, lactose, maltose, propylene glycol, polyethylene glycol, sorbitol, or any mixtures thereof. Some nonlimiting examples of occlusive agents include petrolatum, shea butter, alkyl dimethicones, avocado oil, balm mint oil, canola oil, cod liver oil, corn oil, methicone, mineral oil, olive oil, phenyl trimethicone, trimyristin, soybean oil, glycol distearate, stearyl stearate, synthetic wax, or mixtures thereof. Some non-limiting examples of other moisturizers include cholesterol, cystine, hyaluronic acid, keratin, lecithin, egg yolk, glycine, PPG-12, panthenol, retinol, vegetable oil, or any mixtures thereof. Some non-limiting examples of anti-irritants include bisabolol or panthenol.

[0073] In general, the disinfectant compositions as disclosed herein may be prepared by thoroughly mixing the ingredients at room temperature with a mixer or blender such that a homogeneous mixture is obtained. Commercially available ingredients are typically used without further purification or treatment. For liquid compositions, the ingredients may be dissolved in a solvent or liquid carrier (such as alcohol or water) to form a solution. Individual ingredients may be added during the preparation process in any order.

[0074] Conventional organic acid-based antimicrobial actives that are typically used in liquid disinfectant often present limitations in reaching antimicrobial efficacies at the permitted levels. Advantageously, the present disclosure provides a disinfectant composition, in which the antimicrobial efficacy is enhanced through the unexpected synergy between a first acid having pKa of less than 4 and a second acid having logP of greater than 2. As a result, the disclosed disinfectant compositions may achieve a desirabale level of antimicrobial activity with a reduced amount of the antimicrobial actives, comparable to the currently available commercialized disinfectant products.

[0075] The disclosed disinfectant compositions may provide an enhanced antimicrobial efficacy through the unexpected synergistic effect between a first acid having pKa of less than 4 and a second acid having logP of greater than 2. See, e.g., EXAMPLES 1-3. This unexpected synergy between the first acid having pKa of less than 4 and the second acid having logP of greater than 2, could be achieved against various microorganisms, such as bacteria, yeasts, fungi, spores, viruses, etc. As nonlimiting examples, the disclosed disinfectant compositions may provide a synergistic micro efficacy against the following microorganism: Staphylococcus aureus, Mycobacterium smegmatis, Candida albicans, Mycobacterium bovis, Trychophyton interdigitale, Pseudomonas aeruginosa, and the like. See, e.g., EXAMPLE 1 for S. aureus ; and EXAMPLES 2-3 for P. aeruginosa. Such an enhanced micro efficacy of the disclosed disinfectant compositions may be achieved even without adding oxidizing agent (such as hydrogen peroxide) in the compositions. See, e.g., EXAMPLES 2-3.

[0076] The disclosed liquid antimicrobial compositions may be concentrate compositions, which can be diluted to form use solutions or ready to use (RTU) solutions. The use solutions may be prepared from the concentrate by diluting the concentrate with water at a dilution ratio that provides a use solution having desired detersive properties. The water that is used to dilute the concentrate to form the use composition can be referred to as water of dilution or a diluent, and can vary from one location to another. The typical dilution factor is between approximately 1 :1 and approximately 1 : 10,000 concentrate to water. In some embodiments, the concentrate is diluted at a ratio of between about 1 :10 and about 1 :10,000 concentrate to water, between about 1 :10 and about 1 :1,000 concentrate to water, or between about 1 :10 and about 1 :510 concentrate to water. In some embodiments, the concentrate is diluted at a ratio of about 1 :5, about 1 :10, about 1 :20, about 1 :50, about 1 :100, about 1 :200, or about 1 :500 concentrate to water.

[0077] Further, the disclosed liquid antimicrobial compositions can be provided in various forms well appreciated by those skilled in the art. The compositions can also be manufactured to include a saturated antimicrobial wipe, such as a paper or cloth substrate having the liquid compositions saturated thereon.

[0078] The disclosed solid antimicrobial compositions can be provided in various forms well appreciated by those skilled in the art. The compositions can be manufactured to various forms and sizes. Non-lmiting examples of such solid compositions include powder, tablet, or solid block (e.g., pressed solid, cast solid, or the like).

[0079] The disclosed synergistic disinfectant composition comprises acid component and anionic surfactant, wherein the acid component comprises a first acid having pKa of less than 4 and a second acid having logP of greater than 2.

[0080] In some embodiments, the acid component comprises the first acid having pKa of greater than 2.5 but less than 4, and the second acid having logP of greater than 2.

[0081] In some embodiments, the acid component comprises the first acid having pKa of greater than 2.5 but less than 4, and logP of less than 2; and the second acid having pKa of greater than 2.5 and logP of greater than 2.

[0082] In some embodiments, the acid component comprises the first acid fulfills at least one of the following:

(a) the first acid having pKa of less than 4,

(b) the first acid having pKa of greater than 2.5 but less than 4,

(c) the first acid having pKa of greater than 2.5 but less than 4, and logP of less than 2; and/or the second acid fulfills at least one of the following:

(i) the second acid having logP of greater than 2, (ii) the second acid having pKa of greater than 2.5 and logP of greater than 2.

[0083] In some embodiments, the disinfectant composition may further comprise oxidizing agent, such as hydrogen peroxide.

[0084] In some embodiments, the disinfectant composition may further comprise nonionic surfactant, organic solvent, or any combination thereof.

[0085] In another aspect, the present disclosure provides a method of disinfecting a surface, the method comprising applying a synergistic disinfectant composition as disclosed herein to the surface. Suitable surfaces that may be disinfected using the present compositions include, but are not limited to metal, ceramic, glass, plastic, stainless steel, or wood surfaces. Metal surfaces may include soft metal surfaces, such as aluminum or alloy surfaces. The surface may be a part of a ware, an instrument, a device, furniture, upholstery, or an operational platform used in household, restaurant, healthcare facilities, or other public areas. Examples of household surfaces including, but are not limited to, dishes, cooking wares, cooking devices or appliances, tables, stairs, floors, tiles, sinks, and toilets.

[0086] The disclosed synergistic compositions may also be used to disinfect a body surface of an animal, including human, cat, dog, or other animals. For example, the composition may be used to disinfect the surface of a human’s hand, leg, or other body parts. In some embodiments, the compositions may be used to disinfect human hands.

[0087] The following non-limiting examples illustrate the compositions of the present disclosure and methods of use thereof.

EXAMPLES

[0088] Materials and Methods

[0089] Various acids with different pKa and LogP values were used as shown in the table below.

[0090] General preparation methods. The experimental batches were prepared in lab using the listed ingredients with stepwise addition of each raw material and mixing using a steel blade stirrer at 200 to 300 rpm. The balance water was maintained so that the total composition of the resultant homogeneous mixture was at 100%.

[0091] pH values of the formulations were measured using ASTM E70-07 (pH meter using glass electrode).

[0092] Antimicrobial activities were determined according to the United States Environmental Protection Agency (EPA) standard that applies the “Quantitative Methods for Evaluating the Activity of Microbicides used on Hard, Non-Porous Surface” issued by the Organisation for Economic Co-operation and Development (OECD).

[0093] The term ‘‘log reduction” or “logio reduction" is a mathematical term used to show the relative number of live microbials being reduced from a tested area. For example, “a log reduction of 5” or “a 5-log reduction” means lowering the number of microbials by 10 ⁵ ; “a 4-log reduction” means lowering the number of microbials by 10 ⁴ ; “a 3-log reduction” means lowering the number of microbials by 10 ³ ; “a 2-log reduction” means lowering the number of microbials by 10 ² ; and ‘‘a 1-log reduction” means lowering the number of microbials by 10.

EXAMPLE 1

[0094] TABLE 1 showed the micro efficacy of the tested disinfectant formulations against S. aureus based on the EPA standard according to the OECD Quantitative Methods for Evaluating the Activity of Microbicides.

[0095] Formulation #1 contained phosphoric acid as the only acid in the formulation. Phosphoric acid (pKa1 = 2.16, logP = -2.15) was used as the acid having pKa of less than 4. As shown in TABLE 1 , Formulation #1 provided a 0.45-log reduction against S. aureus. [0096] Formulation #2, which contained octanoic acid as the only acid in the formulation, provided a 1.9-log reduction against S. aureus. Octanoic acid (pKa = 4.90, LogP = 3.05) was used as the acid having logP of greater than 2.

[0097] Formulation #3, which contained decanoic acid as the only acid in the formulation, provided a 2.91 -log reduction against S. aureus. Decanoic acid (pKa = 4.91, LogP = 4.09) each was used as the acid having logP of greater than 2.

[0098] Formulation #4, which contained butyric acid as the only acid in the formulation, provided a 1.88-log reduction against S. aureus. Butyric acid (pKa = 4.82, LogP = 0.79) was used as the acid having logP of less than 2.

[0099] Formulation #5, which contained hexanoic acid as the only acid in the formulation, provided a 1.67-log reduction against S. aureus. Hexanoic acid (pKa = 4.80, LogP = 1.92) was used as the acid having logP of less than 2.

[00100] Formulation #6 contained phosphoric acid (pKa of 2.16) and octanoic acid (LogP of 3.05) as the acids in the formulation. Formulation #6 showed a 4.26-log reduction against S. aureus, which was significantly greater than the additive value of log reductions for Formulation #1 (0.45-log reduction) and Formulation #2 (1.9-log reduction). Therefore, there was a synergistic antimicrobial effect between phosphoric acid (pKa of 3.21) and octanoic acid (LogP of 3.05).

[00101] Formulation #7 contained phosphoric acid (pKa = 2.16) and decanoic acid (LogP of 4.09) as the acids in the formulation. Formulation #7 showed a 5.17-log reduction against S. aureus, which was significantly greater than the additive value of log reductions for Formulation #1 (0.45-log reduction) and Formulation #3 (2.91 -log reduction). Therefore, there was a synergistic antimicrobial effect between phosphoric acid (pKa of 3.21) and decanoic acid (LogP of 4.09).

[00102] Formulation #8, which contained phosphoric acid (pKa of 2.16) and butyric acid (LogP of 0.79) as the acids in the formulation, provided a 2.42-log reduction against S. aureus. Formulation #9, which contained phosphoric acid (pKa of 3.21) and hexanoic acid (LogP of 1.92) as the acids in the formulation, provided a 2.33-log reduction against S. aureus. Formulations #8 and #9 showed that the significant synergistic effect was not observed when phosphoric acid (pKa of 2.16) was used in combination with the acid having LogP less than 2. TABLE 1

EXAMPLE 2

[00103] TABLE 2 showed the micro efficacy of the tested disinfectant formulations against P. aeruginosa based on the EPA standard according to the OECD Quantitative Methods for Evaluating the Activity of Microbicides.

[00104] Formulation #11 contained furoic acid as the only acid in the formulation. Furoic acid (pKa = 3.21, logP = 0.64) was used as the acid having pKa of less than 4. As shown in TABLE 2, Formulation #11 provided a 1.15-log reduction against P. aeruginosa.

[00105] Formulation #12, which contained 2-hydroxybenzoic acid as the only acid in the formulation, provided a 1.36-log reduction against P. aeruginosa. 2- Hydroxybenzoic acid (pKa = 2.97, LogP = 2.26) was used as the acid having logP of greater than 2.

[00106] Formulation #13, which contained 3,4,5-trichlorobenzoic acid as the only acid in the formulation, provided a 1.31-log reduction against P. aeruginosa. 3,4,5-Trichlorobenzoic acid (pKa = 1.70, LogP = 4.40) was used as the acid having logP of greater than 2.

[00107] Formulation #14, which contained 3-hydroxy-4-methoxybenzoic acid as the only acid in the formulation, provided a 1.05-log reduction against P. aeruginosa. 3-Hydroxy-4-methoxybenzoic acid (pKa = 4.35, LogP = 1.25) was used as the acid having logP of less than 2.

[00108] Formulation #15, which contained 2-aminobenzoic acid as the only acid in the formulation, provided a 1.32-log reduction against P. aeruginosa. 2- Aminobenzioc acid (pKa = 4.89, LogP = 1.21) was used as the acid having logP of less than 2.

[00109] Formulation #16 contained furoic acid (pKa of 3.21) and 2- hydroxybenzoic acid (LogP of 2.26) as the acids in the formulation. Formulation #16 showed a 3.39-log reduction against P. aeruginosa, which was greater than the additive value of log reductions for Formulation #11 (1.15-log reduction) and Formulation #12 (1.36-log reduction). Therefore, there was a synergistic antimicrobial effect between furoic acid (pKa of 3.21 ) and 2-hydroxybenzoic acid (LogP of 2.26).

[00110] Formulation #17 contained furoic acid (pKa = 3.21) and 3,4,5- trichlorobenzoic acid (LogP of 4.40) as the acids in the formulation. Formulation #17 showed a 3.54-log reduction against P. aeruginosa, which was greater than the additive value of log reductions for Formulation #11 (0.45-log reduction) and Formulation #3 (2.91 -log reduction). Therefore, there was a synergistic antimicrobial effect between phosphoric acid (pKa = 3.21) and decanoic acid (LogP of 4.09).

[00111] Formulation #18, which contained furoic acid (pKa = 3.21) and 3- hydroxy-4-methoxybenzoic acid (LogP of 1.25) as the acids in the formulation, provided a 1.30-log reduction against P. aeruginosa. Formulation #19, which contained furoic acid (pKa of 3.21) and 2-aminobenzoic acid (LogP of 1.21) as the acids in the formulation, provided a 1.76-log reduction against P. aeruginosa. Therefore, Formulations #18 and #19 showed that there was no synergistic effect when furoic acid (pKa of 3.21 ) was used in combination with the acid having LogP less than 2.

TABLE 2

EXAMPLE 3

[00112] TABLE 3 showed the micro efficacy of the tested disinfectant formulations against P. aeruginosa based on the EPA standard according to the OECD Quantitative Methods for Evaluating the Activity of Microbicides.

[00113] Formulation #21 contained furoic acid as the acid in the only formulation. Furoic acid (pKa = 3.21, logP = 0.64) was used as the acid having pKa of less than 4. As shown in TABLE 3, Formulation #21 provided a 2.11-log reduction against P. aeruginosa.

[00114] Formulation #22, which contained octanoic acid as the only acid in the formulation, provided a 2.02-log reduction against P. aeruginosa. Octanoic acid (pKa = 4.90, Log P = 3.05) was used as the acid having logP of greater than 2.

[00115] Formulation #23, which contained decanoic acid as the only acid in the formulation, provided a 1.96-log reduction against P. aeruginosa. Decanoic acid (pKa = 4.91 , LogP = 4.09) each was used as the acid having logP of greater than 2.

[00116] Formulation #24, which contained butyric acid as the only acid in the formulation, provided a 1.84-log reduction against P. aeruginosa. Butyric acid (pKa = 4.82, LogP = 0.79) was used as the acid having logP of less than 2.

[00117] Formulation #25, which contained hexanoic acid as the acid in the only formulation, provided a 1.65-log reduction against P. aeruginosa. Hexanoic acid (pKa = 4.80, Log P = 1.92) was used as the acid having logP of less than 2.

[00118] Formulation #26 contained furoic acid (pKa of 3.21 ) and octanoic acid (LogP of 3.05) as the acids in the formulation. Formulation #26 showed a 4.62-log reduction against P. aeruginosa, which was greater than the additive value of log reductions for Formulation #21 (2.11-log reduction) and Formulation #12 (2.02-log reduction). Therefore, there was a synergistic antimicrobial effect between furoic acid (pKa of 3.21) and octanoic acid (Log P of 3.05).

[00119] Formulation #27 contained furoic acid (pKa of 3.21) and decanoic acid (LogP of 4.09) as the acids in the formulation. Formulation #27 showed a 4.50- log reduction against P. aeruginosa, which was greater than the additive value of log reductions for Formulation #21 (2.11-log reduction) and Formulation #23 (1.96-log reduction). Therefore, there was a synergistic antimicrobial effect between furoic acid (pKa = 3.21) and decanoic acid (LogP of 4.09).

[00120] Formulation #28, which contained furoic acid (pKa of 3.21) and butyric acid (LogP of 0.79) as the acids in the formulation, provided a 2.37-log reduction against P. aeruginosa. Formulation #29, which contained furoic acid (pKa of 3.21) and hexanoic acid (LogP of 1.92) as the acids in the formulation, provided a 3.00-log reduction against P. aeruginosa. Thus, Formulations #28 and #29 showed that there was no synergistic antimicrobial effect when furoic acid (pKa of 3.21) was used in combination with the acid having LogP less than 2.

TABLE 3

EXAMPLE 4

[00121] TABLE 4 showed the micro efficacy of the tested disinfectant formulations against S. aureus based on the EPA standard according to the OECD Quantitative Methods for Evaluating the Activity of Microbicides.

TABLE 4

[00122] Formulation #30 contained etidronic acid ( aka 1 -hydroxyethylidene- 1 ,1-diphosphonic acid; HEDP) as the only acid in the formulation. Etidronic acid (pKa = 1 .35, LogP = -3.8) was used as the acid having pKa of less than 4. As shown in TABLE 4, Formulation #30 provided a 0.35-log reduction against S. aureus.

[00123] Formulation #31 contained 2-hydroxybenzoic acid (aka salicylic acid) as the only acid in the formulation. 2-Hydroxybenzoic acid (pKa = 2.97, LogP = 2.26) was used as the acid having logP of greater than 2. As shown in TABLE 4, Formulation #31 provided a 3.01-log reduction against S. aureus.

[00124] Formulation #32 contained etidronic acid (pKa of 1.35) and 2- hydroxybenzoic acid (LogP of 2.26) as the acids in the formulation. Formulation #32 showed a 5.40-log reduction against S. aureus, which was greater than the additive value of log reductions for Formulation #30 (0.35-log reduction) and Formulation #31 (3.01 -log reduction). Therefore, there was a synergistic antimicrobial effect between etidronic acid (pKa of 1.35) and 2-hydroxybenzoic acid (LogP of 2.26).

[00125] Various features and advantages of the invention are set forth in the following claims.