Bar Composition with Enhanced Antimicrobial Activity

Abstract

The present invention relates to a mild bar composition with enhanced antimicrobial activity. The bar composition of the present invention is mild and unexpectedly exhibits superior antimicrobial activity when used in cleansing applications. The bar composition comprises an anionic surfactant and an acid and is formulated to produce a cleaning slurry having a pH of 2.9 to 5.2 upon lathering.

Description

[Technical field]

[0001] The present invention relates to a mild bar composition having enhanced antimicrobial activity. In particular, the bar composition of the present invention is mild and unexpectedly exhibits superior antimicrobial activity when used in cleansing applications. The bar composition comprises an anionic surfactant and an acid and is formulated to produce a cleaning slurry having a pH of 2.9 to 5.2 upon lathering. Such bars can be manufactured by conventional techniques such as extrusion techniques and cast melt processes and can be formulated substantially free of ethanol, parabens, formaldehyde donors, silicones, sulfates, and / or halogenated antimicrobial actives. [Background technology]

[0002] Cleansing compositions, such as bars and liquids, are known to have many benefits for consumers who use them. In general, bacteria accumulate on hands, hair, clothes and hard surfaces and can be transmitted from person to person or from object to person through the air and / or daily and normal contact. For example, once on the hands, consumers constantly touch their eyes, nose and mouth, so infection by bacteria is inevitable, causing many diseases such as respiratory and digestive diseases. The Centers for Disease Control reports that washing hands with soap removes bacteria much more effectively than water alone, reducing the chances of catching common illnesses such as diarrhea and colds. In fact, regular use of cleansing compositions reduces the amount of antibiotics people use, making antibiotics less likely to be effective for those who need them.

[0003] Furthermore, cleansing compositions traditionally have biocidal activity against many gram-negative bacteria, and the biocidal activity of cleaning compositions against gram-negative and gram-positive bacteria is fairly limited, especially when the compositions are substantially free of soaps, sulfates, and halogenated actives and are formulated to be very mild on the skin. Summary of the Invention [Problem to be solved by the invention]

[0004] There is an increasing interest in developing bar compositions that exhibit mild and excellent antimicrobial activity when applied to skin, hair, clothing, hard surfaces, and the like. Accordingly, the present invention relates to bar compositions that exhibit unexpectedly excellent antimicrobial activity when used in cleansing applications. The bar compositions include anionic surfactants and acids and are formulated to produce a cleaning slurry having a pH of 2.9 to 5.2. Such bars can be manufactured by conventional techniques, such as extrusion and cast melt techniques, and can optionally be formulated to be substantially free of ethanol, parabens, formaldehyde donors, silicones, sulfates, and / or halogenated antimicrobial actives.

[0005] Additional Information Efforts to produce antibacterial soap bars have been disclosed. US Patent No. 6,794,344 describes a soap-based bar composition containing 50% soap with an alkyl chain length of 8 to 10 carbon atoms.

[0006] Other approaches to creating soap-based formulations have also been disclosed: US Patent Application Publication No. 2010 / 0098776 discloses soap-based liquid cleansing formulations with enhanced deposition of conditioning agents and / or skin appearance improving agents.

[0007] Other approaches to producing soap bar compositions have also been disclosed. WO16024090A1 describes a translucent soap bar composition with antibacterial properties.

[0008] None of the additional information describes a bar composition having enhanced antimicrobial activity as claimed herein. [Means for solving the problem]

[0009] In a first aspect, the present invention provides a method for producing a composition comprising the steps of: a) 18 to 65% by weight of an anionic surfactant; b) 0.2 to 8% by weight of at least one acid having a pKa of 1 to 8 and a logP of 0 to 4.95; and c) 8 to 64% by weight of bar-structured fatty acid, polyalkylene oxide or mixture thereof A bar composition comprising: the bar composition having a pH of 2.9-5.2 at a 10% aqueous slurry, with the proviso that the slurry has a pH greater than 4.45; less than 0.5% by weight of at least one acid having a pKa of 1-8 and a logP of 0-4.95; the bar composition having less than 3% by weight of the sum of betaine, sultaine derived surfactants and mixtures thereof; and further wherein the bar composition is substantially sulfate free.

[0010] In a second aspect, the present invention provides a method for producing a composition comprising the steps of: a) made from a bar composition according to the first aspect of the invention; i) 60-99% by weight water; ii) 1 to 40% by weight of the soluble and insoluble components from the bar composition. contacting the surface with a bath slurry comprising: b) washing said slurry from said surface. 1. A method for reducing the presence of antimicrobial agents (both gram negative and gram positive) on a surface in need thereof, comprising: the soluble and insoluble components make up 20-40% by weight of the total component weight in a slurry including the soluble components in step a), and further wherein the bar composition has antimicrobial activity in a 10% slurry, and has a Log β value against E. coli ATCC 10536 and S. aureus ATCC 6538 of at least 1.0 after 15 seconds (preferably after 10 seconds) of contact with a surface (e.g., skin or countertop) requiring antimicrobial reduction, preferably at least 2.0 after 25 seconds (preferably after 20 seconds) of contact, and most preferably at least 2.75 (preferably 3.0) after 40 seconds (preferably after 35 seconds, most preferably after 30 seconds) of contact. 10 The present invention relates to a method for providing a reduction

[0011] In a third aspect, the present invention provides a Log 30 activity against E. coli ATCC 10536 and S. aureus ATCC 6538 in a 10% aqueous slurry of at least 1.0 after 15 seconds (preferably after 10 seconds) of contact with a surface (e.g., skin or countertop) requiring antimicrobial reduction, preferably at least 2.0 after 25 seconds (preferably after 20 seconds) of contact, and most preferably at least 2.75 (preferably 3.0) after 40 seconds (preferably after 35 seconds, most preferably after 30 seconds) of contact. 10 The present invention relates to the use of the bar composition of the first aspect of the invention to provide a reduction.

[0012] Skin as used herein is meant to include the skin of the arms (including armpits), face, feet, neck, chest, hands, legs, buttocks, and scalp (including hair). "Will dissolve" means water soluble and is defined herein to mean that at least 0.1-1 grams of the bar composition ingredients (i.e., ingredients), such as anionic surfactants, will dissolve in 100 mL of water at 25-50°C. Ingredients means bar composition ingredients and includes water soluble and water insoluble ingredients. Aqueous slurry is defined to be a diluted composition (i.e., a diluted end use bar composition) ready for use in any cleansing application, thus it can be a diluted bar composition that is a shampoo, makeup remover, face wash, or personal wash for body and / or hands. Such aqueous slurries are also suitable as home care cleansers (for inanimate objects), such as cleansers for tables, windows, sinks, toilets, or laundry cleansers. In one embodiment of the present invention, the aqueous slurry is a diluted personal wash composition for skin. In another embodiment, the aqueous slurry is a diluted personal wash composition for hands. The bar composition of the present invention is suitable for delivering pharmaceutical active ingredients (such as corticoids, antihistamines and / or antibiotics) in the slurry. In a preferred embodiment, the bar composition is a cosmetic composition and the aqueous slurry is a cosmetic and non-therapeutic composition suitable for removing dirt (water soluble and oil soluble) from the skin, particularly the skin of the hands. The aqueous slurry is surprisingly mild while at the same time providing antimicrobial benefits. Such slurries are surprisingly mild while at the same time providing antimicrobial benefits. Mild as used herein means having a zein value of ≦10 as defined and measured by the method described in the Examples. The antimicrobial efficacy is a Log Effect against E. coli ATCC10536 and S. aureus ATCC6538 of at least 1.0 after 15 seconds (preferably after 10 seconds) of contact with a surface such as skin in need of antimicrobial reduction, preferably at least 2.0 after 25 seconds (preferably after 20 seconds) of contact, and most preferably at least 2.75 (preferably 3.0) after 40 seconds (preferably after 35 seconds, most preferably after 30 seconds) of contact.10 Bar structuring fatty acids and polyalkylene oxides refer to ingredients that contribute to the hardness and / or foaming properties of the bar composition in the aqueous slurry and are typically solids at temperatures below 40° C. As used herein, pKa is the -log 10 Ka, where Ka is the acid dissociation constant. LogP is log 10 (Partition coefficient), and the partition coefficient P is [compound] オクタノール / [compound] 水 By betaine or sultaine derived surfactants is meant surfactants having a polar head group which is a betaine or sultaine moiety with a fatty portion, which may hereinafter be referred to as betaines and sultaines.

[0013] By substantially free is meant 3.5% or less by weight of the total weight of the bar composition, preferably less than 1.5% by weight of the total weight of the bar composition. In yet another embodiment, substantially free means less than 1% by weight of the total weight of the bar composition, preferably less than 0.5% by weight. As used herein, "substantially free" means including 0.00001% to 3.5% by weight, and 0.00001% to 1% by weight, and 0.00001% to 0.5% by weight, and 0.0% by weight of the total weight of the bar composition. With respect to soap, substantially free (of soap) means less than 9% by weight, preferably less than 8.5% by weight, and most preferably 8% or less by weight of soap based on the total weight of the bar composition. In one embodiment of the invention, the bar composition includes 0.00001 to 5.5% by weight or 0.001 to 4.5% by weight of soap. In another embodiment, the bar composition includes less than 2% by weight or less than 1% by weight of soap or is free of soap (0.0% by weight).

[0014] In yet another embodiment of the invention, the bar composition can be formulated to be substantially free of ethanol, parabens, formaldehyde donors, sulfates, halogenated antimicrobial actives, and any ingredients that have been tested on animals. In another embodiment of the invention, the bar composition contains less than 1% or 0.0% by weight of C (based on the total weight of the bar composition). 16-18 methyl ester sulfonates, glycinates, carboxylates, glutamates, and / or alpha olefin sulfonates. In yet another embodiment, the bar composition comprises less than 2 wt.% silicone, or 0.01-1.5 wt.% or 0.0 wt.% silicone, based on the total weight of the bar composition.

[0015] Skin benefit agents may be used in the solid compositions of the present invention, and such agents may be water-soluble or oil-soluble. The viscosity of the aqueous slurry is 20-1,500 mPa.s, and unless otherwise stated, the viscosity is obtained on a Brookfield heipath helipath TD at 4 rpm for 1 minute at 25°C. Unless expressly stated otherwise, all ranges described herein are intended to include all ranges contained therein. The term comprising is intended to include the terms consisting essentially of and consisting of. For the avoidance of doubt and for the sake of illustration, an aqueous slurry comprising water, an anionic surfactant, and an acid is intended to include slurries consisting essentially of and consisting of. Except in comparative operating examples, or unless otherwise expressly stated, all numbers in this description indicating amounts or proportions of ingredients or conditions and / or physical properties and / or uses of ingredients should be understood to be modified by the word "about." DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] With respect to anionic surfactants suitable for use in the bar compositions of the present invention, such surfactants include glycinates, alpha olefin sulfonates, glutamates, aspartates, aliphatic sulfonates, such as primary alkanes (e.g., C8-C 22) sulfonates, primary alkanes (e.g., C8-C 22 ) Disulfonate, C8-C 22 Alkenesulfonates, C 8- C 22 They may be hydroxyalkanesulfonates or alkyl glyceryl ether sulfonates (AGS), as well as aromatic sulfonates such as alkylbenzene sulfonates.

[0017] The anionic surfactants used in the present invention may optionally contain some alkyl sulfates (e.g., C 12 -C 18 The sulfates may include alkyl sulfates (including alkyl ether sulfates) and / or alkyl ether sulfates (including alkyl glyceryl ether sulfates). As noted herein, the bar compositions of the present invention are substantially free of sulfates. If used, suitable sulfates include those having the formula: [ka] where R is an alkyl or alkenyl having 8 to 18 carbons, preferably 12 to 18 carbons, n has an average value of at least 1.0, preferably less than 5, and most preferably 1 to 4, and M is a solubilizing cation such as sodium, potassium, ammonium, or substituted ammonium. As stated above, sulfates, if optionally used, constitute no more than 3.5% by weight of the bar composition.

[0018] Glycinates such as sodium lauroyl glycinate, sodium cocoyl glycinate, or mixtures thereof are suitable for use, as are glutamates such as sodium lauroyl glutamate and / or sodium cocoyl glutamate.

[0019] As for alpha olefin sulfonates, the same may be optionally used in the bar compositions of the present invention, and when such anionic surfactants are desired, they are generally selected from the group consisting of C 14 -C 16 An olefin sulfonate is used.

[0020] In one embodiment of the invention, the anionic compounds include alkyl sulfosuccinates (monoalkyl and dialkyl, e.g., C6-C 22 including sulfosuccinates); alkyl and acyl taurates (often methyl taurate), alkyl and acyl sarcosinates, sulfoacetates, phosphates and phosphonates C8-C 22 Alkyl, alkyl phosphate esters and alkoxyalkyl phosphate esters, acyl lactates, succinic and maleic acids C8-C 22 Monoalkyls, sulfoacetates, alkylglucosides and acylisethionates are also possible.

[0021] The sulfosuccinate is a monoalkyl sulfosuccinate having the formula: [ka] and amide-MEA sulfosuccinate of the formula: [ka] In the formula, R 1 is C8-C 22 It is an alkyl group.

[0022] Sarcosinates suitable for use are generally represented by the formula: [ka] In the formula, R 2 is C8-C 20 It is an alkyl group.

[0023] Taurates suitable for use are generally characterized by the formula: [ka] In the formula, R 3 is C8-C 20 is an alkyl group, R 4 is a C1-C4 alkyl group and M is a solubilizing cation as previously described.

[0024] Suitable isethionates for use in bar compositions include C8-C 18 Acyl isethionate (C 1-4 These esters are typically prepared by reaction of an alkali metal isethionate with mixed aliphatic fatty acids having 6-18 carbon atoms and an iodine value of less than 20. Often at least 75% of the mixed fatty acids have 12-18 carbon atoms and up to 25% have 6-10 carbon atoms. Isethionates having head-substituted isomers are described in WO 94 / 09763 and U.S. Pat. Nos. 2,810,747 and 2,820,818, the disclosures of which are incorporated herein by reference. In one embodiment of the invention, the acyl moiety of the isethionate is 85-99%, preferably 92-98%, and most preferably 94-97% by weight of a single carbon-carbon chain length, based on the total weight of the acyl moieties on the isethionate.

[0025] The acyl isethionates that can be used can be alkoxylated isethionates such as those described in U.S. Patent No. 5,393,466, entitled "Polyalkoxylated Fatty Acid Esters of Isethionic Acid," issued to Ilardi et al. on Feb. 28, 1995, and incorporated herein by reference. The compounds have the general formula: [ka] In the formula, R 5 is an alkyl group having 8 to 18 carbon atoms, m is an integer of 1 to 4, X and Y are each independently hydrogen or an alkyl group having 1 to 4 carbon atoms, and M is the above-mentioned solubilizing cation.

[0026] Examples of glutamate salts suitable for use in the present invention include sodium lauroyl glutamate, sodium cocoyl glutamate, potassium lauroyl glutamate, potassium cocoyl glutamate, disodium cocoyl glutamate, mixtures thereof, etc. Illustrative examples of aspartic acids suitable for use alone or together with glutamate salts and / or other anionic surfactants include sodium lauroyl aspartate, potassium lauroyl aspartate, sodium cocoyl aspartate, potassium cocoyl aspartate, mixtures thereof, etc.

[0027] Citrates such as laureth-7 citrate are suitable for use as anionic surfactants, as are carboxylates such as sodium laureth-5 carboxylate, sodium lauryl glucose carboxylate, sodium alkylpaleth-8 carboxylate, sodium alkylpaleth-12 carboxylate, etc. Sulfonated tallow fatty acids are yet another class of anionic materials suitable for use.

[0028] Succinates suitable for use in the bar compositions of the present invention include disodium laureth sulfosuccinate, disodium lauryl sulfosuccinate, MEA-sulfosuccinate, or mixtures thereof. Sarcosinates such as sodium and / or potassium lauroyl sarcosinate are also suitable for use.

[0029] In one embodiment of the invention, the anionic surfactant used is sodium cocoyl isethionate, sodium lauroyl isethionate, sodium myristoyl isethionate, sodium oleoyl isethionate, ammonium oleoyl isethionate or mixtures thereof. Other isethionate salts suitable for use include acyl alkyl isethionates such as acyl 1-alkyl, 2-alkyl, and 1,2-alkyl isethionates, the alkyl groups of which are often C1-C4-alkyl, preferably C1 and / or C2 alkyl, and most preferably methyl. In one embodiment of the invention, mixtures of acyl 1-alkyl and acyl 2-alkyl isethionates in weight ratios of 1:25 to 1:2, preferably 1:20 to 1:3, and most preferably 1:18 to 1:4, respectively, can be used, the alkyl groups of which are C1-C6 alkyl, preferably methyl and / or ethyl. In yet another embodiment of the invention, the acyl alkyl isethionate is sodium lauroyl methyl isethionate in a mixture in which at least 50-95%, preferably 60-85%, and most preferably 65-80% of the methyl group is on carbon 2 of the isethionate group, based on the total weight of the isethionate in the bar composition.

[0030] In yet another embodiment, the anionic surfactant is a taurate such as sodium lauroyl taurate, sodium methyl lauroyl taurate, sodium methyl cocoyl taurate, sodium methyl oleoyl taurate, sodium methyl myristoyl taurate, potassium methyl myristoyl taurate, calcium methyl lauroyl taurate, potassium methyl lauroyl taurate, ammonium methyl lauroyl taurate, or mixtures thereof.

[0031] In yet another embodiment of the present invention, the anionic surfactant used in the bar composition of the present invention is a mixture of any of those described herein.

[0032] However, in another embodiment, the anionic surfactant used is an isethionate, a taurate, or a mixture thereof. In the case of a mixture of isethionate and taurate, the mixture typically has a weight ratio of taurate to isethionate of 99:1 to 1:99, preferably 15:85 to 85:15, and most preferably 25:75 to 75:25, based on the total weight of taurate and isethionate in the bar composition. In yet another embodiment, the weight ratio of taurate to isethionate in the bar composition is 35:65 to 65:35, or 58:42 to 42:58, based on the total weight of taurate and isethionate in the bar composition.

[0033] In many cases, and in another embodiment, the anionic surfactant in the bar compositions of the present invention is at least 80% by weight isethionate and / or taurate, preferably at least 90% by weight isethionate and / or taurate, and most preferably at least 95-100% by weight isethionate and / or taurate, based on the total weight of the anionic surfactant in the bar composition. Bar compositions in which the anionic surfactant is 100% by weight isethionate or 100% by weight taurate (based on the total weight of the anionic surfactant in the bar composition) are also within the scope of the present invention. It is also within the scope of the present invention for the bar composition to comprise only anionic surfactants (i.e., 100%) as surfactants in the composition, and thus a bar composition comprising an anionic surfactant and 0.0% by weight betaine is within the scope of the present invention.

[0034] The anionic surfactant typically comprises 18-65% by weight of the bar composition, preferably 20-60% by weight, and most preferably 25-55% by weight. In one embodiment of the invention, the anionic surfactant comprises 23.5-35.5% by weight or 26.5-33.5% by weight of the bar composition.

[0035] Optionally, amphoteric surfactants (which may be zwitterionic depending on pH) suitable for use in the present invention include sodium acylamphoacetate, sodium acylamphopropionate, disodium acylamphodiacetate, and disodium acylamphodipropionate, in which the acyl (i.e., alkanoyl) group is a C7-C 18 The amphoteric surfactant may include an alkyl moiety. Illustrative examples of amphoteric surfactants suitable for use include sodium lauroamphoacetate, sodium cocoamphoacetate, or mixtures thereof. When present, such surfactants comprise 0.00001-6.0%, preferably 0.1-4.5%, and most preferably 0.1-2.5% by weight of the bar composition. The bar composition may comprise 0.00001-1% amphoteric surfactant, or may be completely free (0.0% by weight) of the bar composition.

[0036] Regarding the zwitterionic surfactants that may optionally be used in the present invention, such surfactants contain at least one acid group. Such acid group may be a carboxyl or sulfonic acid group. They often contain a quaternary nitrogen and therefore may be quaternary amino acids. They often contain an alkyl or alkenyl group of 7 to 18 carbon atoms and typically conform to the overall structural formula: [ka] In the formula, R 6 is an alkyl or alkenyl having 7 to 18 carbon atoms; R 7 and R 8 each independently represents an alkyl, hydroxyalkyl, or carboxyalkyl group having 1 to 3 carbon atoms; q is 2 to 4 and r is 0 to 1; A is an alkylene group having 1 to 3 carbon atoms which may be substituted with hydroxyl, and B is -CO2- or -SO3-.

[0037] Suitable zwitterionic surfactants for optional use in the present invention include simple betaines of the formula: [ka] and amidobetaines of the following formula: [ka] In the formula, t is 2 or 3. In both equations, R 6 , R 7 and R 8 is as defined above. R 6 In particular, coconut oil-derived C 12 and C 14 A mixture of alkyl groups means that R 6 At least half, preferably at least three quarters, of the groups have 10 to 14 carbon atoms. 7 and R 8 is preferably methyl.

[0038] Another option is where the zwitterionic surfactant is a sulfobetaine of the formula: [ka] or [ka] [wherein u is 2 or 3.] or -(CH2)3SO3 - -CH2C(OH)(H)CH2SO3 - These are variants of the . In these formulas, R 6 , R 7 and R 8 is as defined above.

[0039] Specific examples of zwitterionic surfactants suitable for use include coco betaine, cocoamidopropyl betaine, lauryl betaine, lauryl hydroxysulfobetaine, lauryl dimethyl betaine, cocoamidopropyl hydroxysulfobetaine, behenyl betaine, capryl / capramidopropyl betaine, coco dimethyl carboxymethyl betaine, stearyl betaine, lauryl amidopropyl betaine, mixtures thereof, and the like. Additional zwitterionic surfactants suitable for use include lauryl hydroxysultaine and / or cocamidopropyl sultaine. In a preferred embodiment, the zwitterionic surfactant used in the bar composition of the present invention is cocamidopropyl betaine.

[0040] When zwitterionic surfactants are used, they may comprise 0.0001-8%, preferably 1.0-6%, and most preferably 2-5% by weight of the bar composition. The bar composition may comprise 0.0001-3.5% zwitterionic surfactant, 2.5-3.5% zwitterionic surfactant, or none at all (0.0% weight) based on the weight of the bar composition when the pH of the 10% wash slurry is greater than 4.45. When the bar composition comprises less than 3%, preferably less than 2%, and most preferably less than 1% by weight of the total of betaine and sultaine derived surfactants and mixtures thereof, based on the weight of the bar composition. In one embodiment of the invention, the total of zwitterionic surfactants such as betaines and / or sultaines when used in the present invention comprises 0.05-10%, preferably 0.08-8%, and most preferably 0.5-6.5% by weight of the total weight of zwitterionic and anionic surfactants used in the bar composition. In yet another embodiment, the sum of the betaine and / or sultaine comprises 1-2.5 wt. % of the bar composition and the anionic surfactant comprises 26-36 wt. %. In another embodiment, the sum of the betaine and / or sultaine derived surfactants (total) comprises 0.5-2.75 wt. % of the bar composition and the anionic surfactant comprises 26.5-35 wt. % of the bar composition. In yet another embodiment, when betaine and / or sultaine are used in the bar composition of the present invention, the anionic surfactant comprises less than 7 wt. %, preferably less than 5 wt. %, and most preferably less than 4 wt. % taurate, based on the total weight of the anionic surfactant in the bar composition. In yet another embodiment, when betaine and / or sultaine are used, the anionic surfactant comprises 0.001-3.5 wt. % taurate or no taurate (0.0 wt. %), based on the total weight of the anionic surfactant.

[0041] Nonionic surfactants may also be used in the bar compositions of the present invention. When nonionic surfactants are used, they are typically present at low levels of 0.5, 1, 1.5 or 2% to high levels of 6, 8, 10 or 12% by weight of the bar composition. Nonionic materials that can be used include, among others, compounds having a hydrophobic group and a reactive hydrogen atom, such as the reaction products of aliphatic alcohols, acids, amides or alkylphenols with alkylene oxides, especially ethylene oxide alone or with propylene oxide. Specific nonionic surfactant compounds include alkyl (C6-C 22 ) Phenol ethylene oxide condensate, aliphatic (C8-C 18 ) The condensation products of primary or secondary straight or branched chain alcohols with ethylene oxide, and the products produced by the condensation of ethylene oxide with the reaction products of propylene oxide and ethylenediamine.Other nonionic surfactants include long chain tertiary amine oxides, long chain tertiary phosphine oxides, dialkyl sulfoxides, etc.

[0042] Nonionic surfactants that may be used include fatty acid / alcohol ethoxylates having the following structure: a) HOCH2(CH2) s (CH2CH2O) v H or b) HOOC(CH2) c (CH2CH2O) d H, in which s and v are each independently an integer up to 18, and c and d are each independently an integer greater than or equal to 1. In one embodiment of the invention, s and v are each independently an integer between 6 and 18, and c and d are each independently an integer between 1 and 30. Other options for nonionic surfactants include those of the formula HOOC(CH2) l -CH=CH-(CH2) k (CH2CH2O) z H, in which i and k are each independently 5 to 15, and z is 5 to 50. In another embodiment of the present invention, i and k are each independently 6 to 12, and z is 15 to 35.

[0043] The nonionic surfactant may also be a sugar amide, such as a polysaccharide amide. Specifically, the surfactant may be one of the lactobionamides described in U.S. Patent No. 5,389,279 to Au et al., entitled "Compositions Containing Nonionic Glycolipid Surfactants," issued on February 14, 1995, which is incorporated herein by reference. Or, it may be one of the sugar amides described in U.S. Patent No. 5,009,814 to Kelkenberg, entitled "Use of N-Polyhydroxyalkyl Fatty Acid Amides as Thickeners for Liquid Aqueous Surfactant Systems," issued on April 23, 1991, which is incorporated herein by reference.

[0044] In one embodiment of the present invention, cationic surfactants may be used in the bar compositions of the present invention. One class of optional cationic surfactants includes heterocyclic ammonium salts such as cetyl or stearyl pyridinium chloride, alkylamidoethyl pyridinium methylsulfate, and lapyrium chloride.

[0045] Tetraalkylammonium salts are another useful class of cationic surfactants suitable for any application. Examples include cetyl or stearyl trimethylammonium chloride or bromide, coconut or tallow trimethylammonium halide, behenyl trimethylammonium halide or methyl sulfate, decyl isononyl dimethyl ammonium halide, ditallow (or distearyl) dimethyl ammonium halide, and behenyl dimethyl ammonium chloride.

[0046] Still other types of cationic surfactants that can be used include various ethoxylated quaternary amines and ester quats, such as PEG-5 stearyl ammonium lactate (e.g., Genamin KSL from Clariant), PEG-2 coco ammonium chloride, PEG-15 hydrogenated tallow ammonium chloride, PEG 15 stearyl ammonium chloride, dipalmitoyl ethyl methyl ammonium chloride, dipalmitoyl hydroxyethyl methyl sulfate, and stearyl amidopropyl dimethylamine lactate.

[0047] Further optional cationic surfactants suitable for any use also include quaternized hydrolysates of silk, wheat and keratin proteins, and it is within the scope of the present invention to use mixtures of the aforementioned cationic surfactants.

[0048] If a cationic surfactant is used, it will comprise no more than 0.75% by weight of the bar composition. If present, it will typically comprise 0.001 to 0.7% by weight of the bar composition, more typically 0.01 to 0.5% by weight or 0.0% by weight.

[0049] In one embodiment of the invention, the bar composition of the invention can optionally comprise 0.0001-0.5 wt.% of a polymeric quaternary ammonium compound (including salts thereof). In another embodiment, the bar composition comprises less than 0.3 wt.% of a polymeric quaternary ammonium compound. In yet another embodiment, the bar composition comprises less than 0.01 wt.% of a polymeric quaternary ammonium compound. In yet another embodiment, the bar composition is free of polymeric quaternary ammonium compounds (i.e., 0.0 wt.%).

[0050] Surfactants suitable for use in the present invention are available from suppliers such as Stepan Company, Clariant AG, Croda, Galaxy Surfactants, Sino Lion, Innospec, and Dow Chemical.

[0051] The acid suitable for use in the present invention is limited only insofar as it is suitable for use in consumer products and has a pKa of 1 to 8 and a logP of 0 to 4.95. Such acids are meant to include acids that are mono- and dicarboxylic acids, unsaturated acids, aromatic acids, phosphonic acids, or mixtures thereof.

[0052] In one embodiment of the invention, the acid (or mixture of acids used) has a pKa of 1.5 to 7, preferably 2 to 6.5, most preferably 2 to 5.5. In another embodiment of the invention, the pKa of the acid used is 2.5 to 4.8. In yet another embodiment, the pKa is 2.75 to 3.25. In one embodiment of the invention, the logP of the acid used is 0.65 to 4, preferably 1 to 3.3, most preferably 1.2 to 3. In yet another embodiment, the logP of the acid is 1.4 to 2.8 or 1.6 to 2.6.

[0053] With regard to the carboxylic acids suitable for use, illustrative examples include propionic acid, n-butyric acid, isobutyric acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid and / or decanoic acid. Dicarboxylic acids suitable for use include adipic acid and / or pimelic acid. Carboxylic acids may also include unsaturated ones such as acrylic acid, but-3-enoic acid, but-2-enoic acid, crotonic acid, isocrotonic acid, sorbic acid, angelic acid, tiglic acid and / or tetrol acid. It is also within the scope of the present invention to use the class of aromatic acids or in combination with other acids. Aromatic acids suitable for use include coumaric acid, benzoic acid, p-aminobenzoic acid, salicylic acid, capryloyl salicylic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid and / or gallic acid. Phosphonic acids suitable for use include 4-ethoxyphenylphosphonic acid, 4-methylphenylphosphonic acid, 4-chlorophenylphosphonic acid, phenylphosphonic acid, or mixtures thereof.

[0054] It is within the scope of the present invention to include any combination of acids having a pKa of 1-8 and a logP of 0-4.75, as described herein. In one embodiment of the present invention, the acid used is benzoic acid, p-aminobenzoic acid, capryloyl salicylic acid, and / or salicylic acid. In another embodiment, the acid used comprises salicylic acid and benzoic acid in a weight ratio of 5:95-95:5, preferably 25:75-75:25, and most preferably 40:60-60:40. In another embodiment of the present invention, the acid used consists essentially of salicylic acid and benzoic acid in a weight ratio of 5:95-95:5, preferably 25:75-75:25, and most preferably 40:60-60:40. In yet another embodiment of the present invention, the acids used are salicylic acid and benzoic acid in a weight ratio of 5:95 to 95:5, preferably 25:75 to 75:25, most preferably 40:60 to 60:40.

[0055] In yet another embodiment of the invention, the acids used are all benzoic acids (100% by weight of acids having pKa 1-8 and logP 0-4.75) or all salicylic acids.

[0056] Regarding the amount of such acid used, typically 0.2 to 8%, preferably 0.2 to 7%, and most preferably 0.25 to 6.5% acid is used based on the total weight of the bar composition. In one embodiment of the invention, 0.275 to 5.75% by weight acid is used. In yet another embodiment, 0.325 to 5.5% by weight acid is used based on the total weight of the bar composition.

[0057] In one embodiment of the invention, the amount of soap used in the bar composition of the invention is 1.1 to 2.4 times, or 1.2 to 2.3 times, or 1.2 to 2.2 times the amount of acid having a pKa of 1 to 8 and a logP of 0 to 4.95 used in the invention, provided that the amount of soap does not exceed 9% by weight of the bar composition.

[0058] With respect to the bar structured fatty acid used to construct or form the bar composition of the present invention, it is often a C8-C 18 , preferably C12 ~C 18 , most preferably C 16 ~C 18 It is a blend of fatty acids.

[0059] Water-soluble polyalkylene oxide structurants may also be included as part of the composition as structurants, with or without fatty acid structurants. The water-soluble structurant should be suitable for melting in the temperature range of 40°C to 100°C to form the bar composition, but should be solid at the temperature at which the bar is to be used. Preferably, the structurant has a melting point of at least 50°C to 90°C. Materials suitable for use as water-soluble structurants are medium to high molecular weight polyalkylene oxides having the above melting points, in particular polyethylene glycols or mixtures thereof. Polyalkylene glycols (particularly polyethylene glycols or PEGs) that can be used typically have a weight average molecular weight in the range of 1,500 to 10,000 (preferably 7,000 to 9,000). In one embodiment of the invention, it is desirable to include a fairly small amount (less than 10% of the total structurant) of polyethylene glycol having a weight average molecular weight in the range of 50,000 to 500,000, in particular a molecular weight of 90,00 to 110,000. In one embodiment of the invention, the bar structurant is not entirely polyalkylene oxide, whereby when intended to be part of the bar composition it is present in a weight ratio of polyalkylene oxide to fatty acid structurant of from 3:1 to 2:1, preferably from 1.8:1 to 1.35:1. In one embodiment of the invention, the bar structurant is 15 to 100% by weight, or 30 to 90% by weight, or 45 to 70% by weight of fatty acid, based on the total weight of the bar structurant used. In yet another embodiment, the bar structurant is stearic acid or stearic acid mixed with 100% by weight of fatty acid, in particular 1 to 20% by weight of lauric acid, based on the total weight of stearic acid and lauric acid in the bar composition.

[0060] Typically, the bar structured fatty acid and / or water soluble polyalkylene oxide will comprise 8-64% or 8-45%, preferably 10-40% (or 10-41%), and most preferably 20-40% (or 20-41%) by weight of the bar composition. In yet another embodiment, the bar composition comprises 21-39% or 27-37% by weight of structurant, based on the total weight of the bar composition.

[0061] With respect to soaps suitable for optional use in the bar compositions of the present invention, these typically include high chain C soaps such as sodium or potassium palmitate or stearate soaps (palmitic and stearic acid soaps). 16 ~C 18 There may be insoluble soaps (i.e. bricks) consisting of soaps, which are generally included in the bar composition to ensure the strength of the bar body, thereby contributing a structuring effect, for example allowing the bar composition to maintain its shape. The bar compositions of the present invention may also consist of water-soluble fatty soaps (mortar-like), which are traditionally unsaturated C18:1 and / or 18:2 sodium or potassium soaps (oleic acid soaps) in combination with short chain fatty acids (generally C8-C14 soaps).

[0062] Again, when a salt of a carboxylic acid (i.e., soap) is used, it typically constitutes less than 9.0 wt.%, preferably less than 8.5 wt.%, and most preferably 8 wt.% or less of soap, based on the total weight of the bar composition. In an embodiment of the invention, the bar composition comprises 0.00001-5.5 wt.% or 0.001-4.5 wt.% soap. In another embodiment, the bar composition comprises less than 2 wt.%, less than 1 wt.%, or no soap (0.0% wt.), based on the total weight of the bar composition.

[0063] Water typically comprises 0.0-13% by weight of the bar composition, preferably 2-12% by weight, most preferably 3-10% by weight, hi one embodiment of the invention, water comprises 3-9% or 4-7% by weight of the bar composition.

[0064] For the cleaning slurry, the pH is 2.9-5.2, preferably 3.3-4.9, most preferably 3.9-4.8. In another embodiment, the pH of the cleaning composition is 3.9-4.55, or 3.9-4.45, or 4.0-4.42. The viscosity of the cleaning slurry is 20-1,500 mPa·s, preferably 30-1,300 mPa·s, most preferably 100-800 mPa·s. Again, when the pH of the cleaning slurry is greater than 4.45 and the bar composition comprises less than 0.5 wt.% of at least one acid having a pKa of 1-8 and a logP of 0-4.95, the bar composition comprises less than 3 wt.% of a betaine and / or sultaine derived surfactant.

[0065] Optional ingredients that can be used in the bar compositions of the present invention include preservatives to prevent the growth of potentially harmful microorganisms when preparing the end-use cleaning composition. Suitable conventional preservatives that can be used include propionate salts and various quaternary ammonium compounds. Often preferred preservatives are potassium sorbate, iodopropynyl butylcarbamate, phenoxyethanol, wasabi-based preservatives, imidazolidinyl urea, sodium dehydroacetate, and benzyl alcohol. Often desirable additives suitable for use in the bar compositions of the present invention are 1,2-alkanediols, such as 1,2-octanediol, 1,2-hexanediol, or mixtures thereof. The bar compositions may be comprised of a preservative system that is formaldehyde-free, paraben-free, or both, but is preferably preservative-free, especially when the bar contains less than 12% water by weight.

[0066] Conventional fragrance ingredients may be added to the bar composition, such as eugenol, coumarin, linalyl acetate, citronellal, iris concentrate, terpinyl acetate, terpineol, thymol, pinenes (e.g., α-pinene and β-pinene) and citronellol, etc. Such ingredients will comprise from 0.01 to 1.2% by weight of the bar composition when in use, preferably from 0.1 to 1% by weight.

[0067] If used, conventional preservatives, vicinal diols and / or fragrance ingredients comprise no more than 2% of the bar composition, preferably no more than 1%, and most preferably 0.2-0.85%. In one embodiment of the invention, 0.2-0.8% by weight of any preservative, vicinal diol and / or fragrance ingredient is used, based on the total weight of the bar composition. In one embodiment of the invention, no preservatives, vicinal diols and / or fragrance ingredients (other than those provided in the fragrance used in the bar composition) are used in the bar composition.

[0068] Other optional ingredients suitable for use, particularly when the bar composition is used as an anti-dandruff shampoo, include zinc pyrithione, octopirox, or mixtures thereof. Each of these materials may range from 0.05 to 3% by weight, preferably 0.1 to 2% by weight, of the total weight of the bar composition.

[0069] Additional optional ingredients that may be used include sensory oils and / or exfoliants. Desirable oils include rose, lime, coconut, lavender, argan, sweet almond oil, or mixtures thereof. Exemplary exfoliants that may be used include salt, sugar, apricot, walnut shells, rice, nutmeg, and / or oatmeal powder. If used, sensory oils and exfoliants may comprise 0.1-2% by weight of the bar composition, with the proviso that the combined amount of flavor and sensory oil does not exceed 2.5% by weight of the composition, and preferably does not exceed 2.0% by weight of the composition.

[0070] The bar composition may also contain vitamins. Examples of vitamins include vitamin B2, vitamin B3 (niacinamide), vitamin B6, vitamin C, vitamin E, folic acid and biotin. Derivatives of vitamins may also be used. For example, vitamin C derivatives include ascorbyl tetraisopalmitate, magnesium ascorbyl phosphate and ascorbyl glycosides. Derivatives of vitamin E include tocopheryl acetate, tocopheryl palmitate and tocopheryl linoleate. DL-panthenol and derivatives may also be used. The total amount of vitamins, when present, may range from 0.001 to 5%, preferably 0.01 to 3%, optimally 0.1 to 1% by weight of the composition.

[0071] Other optional additives suitable for use include resorcinols such as 4-ethylresorcinol, 4-hexylresorcinol, 4-phenylethylresorcinol, dimethoxytolylpropylresorcinol, 4-cyclopentylresorcinol, 4-cyclohexylresorcinol, thiamidol, etc.; alpha- and / or beta-hydroxy acids; retinoic acid and its derivatives (e.g., cis and trans); retinal; retinol; retinyl esters such as retinyl acetate, retinyl palmitate, and retinyl propionate; petroselinic acid; conjugated linoleic acid; 12-hydroxystearic acid; mixtures thereof, etc. Conditioning agents such as polyquaternium compounds (e.g., polyquaternium-67) may also be desirable for inclusion in the present invention. Such additives, if used, collectively comprise 0.001 to 7%, preferably 0.01 to 6%, and most preferably 0.1 to 5% by weight of the bar composition.

[0072] Desquamation promoters may be present. Examples include alpha-hydroxycarboxylic acids, beta-hydroxycarboxylic acids. The term "acid" refers to the free acid as well as its salts, C1-C 30It is also meant to include alkyl or aryl esters, and lactones formed by removal of water to form cyclic or linear lactone structures. Representative acids are glycolic acid and its derivatives, lactic acid, and malic acid. The amounts of these materials, when present, can range from 0.01 to 3%, preferably 0.1 to 2%, by weight of the bar composition.

[0073] The cosmetic cleanser compositions of the present invention may optionally contain a variety of herbal extracts. Representative extracts include those extracted from green tea, yarrow, ginseng, marigold, hibiscus, ginkgo, chamomile, licorice, aloe vera, grape seed, unshu mandarin, willow bark, sage, and rosemary. Humectants such as glycerol and other polyols (e.g., sorbitol) may also be included. Humectants and / or extracts such as sorbitol, if used, typically comprise 0.01 to 5% by weight of the bar composition, preferably 0.01 to 4% by weight, and most preferably 0.02 to 3% by weight.

[0074] Another optional additive suitable for use includes cannabis oil containing 2.5-25% by weight of cannabigerol and / or 0.5-10% by weight of cannabidiol. If used, such oil will comprise 0.0001-5% by weight of the composition, preferably 0.01-3% by weight of the bar composition.

[0075] Also suitable for use are optionally chelating agents (e.g., EDTA), opacifiers (TiO2, particle size 50-1200 nm, preferably 50-350 nm), kaolin, bentonite, zinc oxide, iron oxide, mica, C 8-22Materials such as fatty acid substituted sugars, lipoic acid, retinoxytrimethylsilane (available from Clariant Corp. under the trade name Silcare 1M-75), dehydroepiandrosterone (DHEA), or mixtures thereof. Ceramides (such as ceramide 1, ceramide 3, ceramide 3B, and ceramide 6) and pseudoceramides can also be optionally included, as well as 10- and / or 12-hydroxystearic acid. The amounts of these additional and optional materials, if used, can range from 0.0001 to 3%, preferably 0.001 to 2%, and most preferably 0.001 to 1.5% by weight of the bar composition.

[0076] Colorants or pigments may also be included in the bar composition. If used, these materials may range from 0.05 to 5%, preferably 0.1 to 2% by weight of the composition.

[0077] Conditioning agents such as hydroxypropyltrimonium chloride, 5-ureidohydantoin and / or glyoxyldiureide can be used. If used, these ingredients comprise 0.5-4%, preferably 0.75-3%, and most preferably 1-2% by weight of the bar composition.

[0078] The bar compositions of the present invention may also optionally include a sunscreen active. Particularly preferred are materials such as p-ethylhexyl methoxycinnamate available as Parsol MCX®, Avobenzene available as Parsol 1789®, and Benzophenone-3, also known as Oxybenzone. Inorganic sunscreen actives such as particulate titanium dioxide, zinc oxide, polyethylene, and various other polymers may also be used. Amounts of sunscreen when present may generally range from 0.01 to 3%, preferably from 0.5 to 2%, optimally from 0.75 to 1.5% by weight of the bar composition.

[0079] Conventional buffers / pH adjusters can be used, including commonly used additives such as sodium hydroxide, potassium hydroxide, ammonium hydroxide, hydrochloric acid, citric acid / citric acid buffer, triethanolamine, or mixtures thereof, and pH is measured using a Thermo Fisher Scientific pH meter.

[0080] Any antimicrobial component may be used, but is not required. Exemplary components include quaternary ammonium compounds such as cetylpyridinium chloride, cetyltrimethylammonium chloride, cetyltrimethylammonium bromide, benzalkonium chloride, benzethonium chloride, cetrimide, or mixtures thereof. Certrimonium chloride and / or bromide, chloroxylenol, antimicrobial lipids, antimicrobial peptides, or mixtures thereof may also be used. Triclosan may also be used, but is generally undesirable. A mixture of thymol and terpineol is often desired in use, typically in a weight ratio of 1:3 to 3:1, or 1:2 or 2:1, or 1:0.7 to 0.7:1. If used, such optional antimicrobial components comprise 0.001 to 6%, preferably 0.01 to 5%, and most preferably 0.01 to 2.5% by weight of the bar composition.

[0081] Conventional and art-recognized extrusion and casting melt techniques can be used to prepare the bar compositions. A wide variety of packaging can be used for the bar compositions of the present invention. Boxes, bags, recycled wrap, metal containers, and plastic containers can be used. Preferably, the packaging used with the bar compositions of the present invention is packaging made from recycled materials, such as post-consumer resins or biodegradable materials. Most preferably, the bar compositions are sold in biodegradable packaging materials, such as paper or cardboard materials. In a particularly preferred embodiment, the bar compositions are used by the consumer directly from the biodegradable packaging.

[0082] When washing surfaces, including skin and hair, with an aqueous slurry made from the bar composition of the present invention, the water is often at 32-46°C, preferably 34-44°C, and most preferably 35-42°C. Rubbing the bar composition with water onto the hands or onto the desired surface with water is a typical means for making the aqueous slurry. The aqueous (or bar) slurry typically contains 60-99%, or 70-97%, or 75-95%, or 80-92% water by weight. The aqueous slurry also contains 1-40%, or 5-30%, or 6-15% soluble and insoluble components from the bar composition by weight. Washing should last for at least 10 seconds, preferably 20 seconds or more, and most preferably at least 30 seconds.

[0083] The following examples are provided to facilitate understanding of the invention and are not intended to limit the scope of the claims. EXAMPLES

[0084] Aqueous slurries were prepared by mixing gratings from bars made in the samples of Table I with water to form test solutions containing 10% by weight of the initial bar ingredients. In a second method, the raw bar ingredients shown in the samples of Table II were mixed with water to form test solutions containing a total of 10% raw bar ingredients to simulate aqueous slurries of the bar compositions. For each sample, the aqueous slurries were mixed at 50° C. to simulate typical consumer wash conditions.

[0085] Regarding microorganisms, E. coli ATCC10536 and S. aureus ATCC6538 were used in this study to represent Gram-negative and Gram-positive bacteria, respectively. The bacteria were stored at -80°C. Freshly isolated strains were cultured on tryptic soy agar plates at 37°C for 24 hours before each experiment, in duplicate.

[0086] Test solutions were prepared. In the first method, and for aqueous slurries made from the bar compositions listed in Table I, the compositions (typically containing up to 15% surfactant) were mixed with water to form test solutions containing 10% weight percent of the initial formulation. In the second method, and for the ingredients combined in Table II, the same were mixed with water at a level simulating a 10% dilution of the slurry. For each evaluation, the test solutions were heated and mixed at 70° C. The test solutions were allowed to cool to room temperature (25° C. overnight) before testing.

[0087] The time-kill assay was adapted from ASTM International Test Method ASTM E2315-16, entitled "Standard Guide for Evaluating Antimicrobial Activity Using the Time-Kill Procedure," which is incorporated herein by reference. Following this procedure, 1.5x10 8 ~5x10 8 Colony forming units / mL (CFU / mL) of vegetative bacterial cultures were treated with the test solutions (prepared as described in the table) at 46°C. Eight parts by weight of the 10% test sample prepared as above was mixed with 1 part by weight of bacterial culture and 1 part by weight of water. After 30 seconds of exposure, the resulting mixture was neutralized to stop the antibacterial activity of the test solution. The neutralized bacterial solution was serially diluted, plated on solid media, incubated for 24 hours, and viable cells were enumerated by colony counting. Antibacterial activity is defined as the log reduction in CFU / mL relative to the bacterial concentration at 0 seconds. The evaluation time was 30 seconds and Log 10 A reduction of 2.75 or greater was acceptable and considered a pass. Cultures not exposed to any test solution (i.e., containing neither the listed acids nor traditional antimicrobial actives) served as untreated controls.

[0088] The log reduction was calculated using the following formula: Log 10 Decrease=Log 10 (Untreated control CFU)-Log 10 (Test sample CFU).

[0089] Example I Low moisture bar compositions, Samples 1-7, were made using the ingredients listed in Table I below. The synthetic detergent and pre-made ribbons were melted and subjected to blow molding, extrusion or casting melt processing steps to produce the indicated bar compositions. 10 The decrease was measured after 30 seconds.

[0090] Table I [Table 1]

[0091] As can be seen from the data, aqueous slurries prepared from bar compositions consistent with the present invention (Samples 1-4) unexpectedly provided superior antimicrobial reduction. The aqueous slurries were also evaluated / used by trained panelists, all of whom concluded that the compositions were gentle on the skin, even though the pH of the slurries was lower than the natural pH of skin.

[0092] Example II Samples 8-15 in Table II were also prepared as aqueous slurries containing the bar composition ingredients, with the amounts provided being weight percent weights based on the total weight of the aqueous slurry, reflecting slurries prepared from water and 10% bar composition.

[0093] Table II [Table 2]

[0094] As can be seen from the data, the aqueous slurries (samples 8, 9, 10, and 12) prepared to reflect the diluent bar composition consistent with the present invention unexpectedly provided superior antimicrobial reduction. The aqueous slurries were also evaluated / used by trained panelists, all of whom concluded that the compositions were gentle on the skin, even though the pH of the slurries was lower than the natural pH of the skin. Although a log reduction of at least 2.7 was achieved 30 seconds after contact, lactic acid, which does not meet the criteria of the present invention, was ineffective against S. aureus.

[0095] Example III Bar formulations A-D were prepared with the ingredients listed and evaluated for antimicrobial efficacy as described above and skin mildness as defined in this example. The results for the bar compositions consistent with the present invention were compared to a commercially available bar composition.

[0096] Zein mildness assay Zein mildness of the aqueous slurries was evaluated by combining 0.3 g of zein powder (Sigma. 23625-1 kg, Lot No. SLBZ2926 or Acros Organic™ Zein) with 10 mL of a 1% diluted aqueous solution of the bar composition. The resulting combination was blended for 30 minutes at 25° C. The resulting mixture was visually inspected to determine if excess undissolved zein was present. If no excess zein was present, an additional 0.3 g of zein was added to the mixture and blended for an additional 30 minutes. The resulting mixture was then filtered using a 0.45 micron filter. The filtrate was diluted with a 2% sodium dodecyl sulfate solution and the absorbance at 298 nm was measured to determine the amount of zein dissolved. A control experiment at 1% of the corresponding bar composition without zein was prepared in a similar manner and measured at 298 nm to determine the background. The amount of zein dissolved is reported as follows: Zein absorbance = [Absorbance of Zein in Liquid Composition (298 nm) - Absorbance of Background Composition (298 nm)] x Dilution Factor. Milder products will have less dissolved zein and lower absorbance values. Zein absorbance ranges that allow for a ranking of product mildness with respect to their ability to irritate the skin are defined and illustrated in Table III below.

[0097] Table III Zein Absorbance Values ​​of Bar Compositions [Table 3]

[0098] [Table 4]

[0099] The data in Table III unexpectedly show that inventive Formulations A-C made in accordance with the present invention exhibited unexpectedly superior antimicrobial efficacy while at the same time being surprisingly mild to the skin. Example D, not made in accordance with the present invention, demonstrated that mildness was achieved but that antimicrobial efficacy, particularly against gram-positive bacteria, was significantly reduced. When compared to the commercially available bar composition, the data unexpectedly show that inventive Formulations A-C provide the surprising and unexpected benefit of being gentle to the skin yet superior in antimicrobial efficacy.

Claims

1. a) 18 to 65% by weight of an anionic surfactant; b) 0.2-8% by weight of at least one acid having a pKa of 1-8 and a logP of 0-4.95; c) 10-64% by weight of bar structured fatty acid A bar composition comprising:

1. A bar composition, wherein the bar composition in a 10% aqueous slurry has a pH of 2.9-5.2, with the proviso that the slurry has a pH greater than 4.45; wherein the bar composition has 0.5% by weight or less of at least one acid having a pKa of 1-8 and a logP of 0-4.95; wherein the total of betaine, sultaine derived surfactants and mixtures thereof in the bar composition is less than 3% by weight; and wherein the bar composition is substantially free of sulfates, where substantially free means 3.5% by weight or less of the total weight of the bar composition.

2. 2. The bar composition of claim 1, wherein the anionic surfactant comprises 20-60% by weight of the composition and comprises a mixture of taurate and isethionate in a weight ratio of 99:1 to 1:99, and the surface is skin.

3. 3. The bar composition of claim 1 or 2, wherein the acid has a pKa of 1.5 to 7, or 2.5 to 4.8, or 2.75 to 3.25, and a logP of 0.65 to 4, or 1 to 3.3, or 1.2 to 3.

4. 10. The bar composition of any one of the preceding claims, wherein the acid is propionic acid, n-butyric acid, isobutyric acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, pimelic acid, but-3-enoic acid, but-2-ynoic acid, crotonic acid, isocrotonic acid, sorbic acid, angelic acid, tiglic acid, tetrolic acid, coumaric acid, benzoic acid, p-aminobenzoic acid, salicylic acid, capryloyl salicylic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, gallic acid, 4-ethoxyphenylphosphonic acid, 4-methylphenylphosphonic acid, 4-chlorophenylphosphonic acid, phenylphosphonic acid, or mixtures thereof.

5. 5. The bar composition of claim 4, wherein the acid is benzoic acid, p-aminobenzoic acid, salicylic acid, capryloyl salicylic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, or mixtures thereof.

6. 6. The bar composition of claim 5, wherein the acid is benzoic acid or salicylic acid or a mixture thereof and the anionic surfactant is at least 90% by weight isethionate.

7. 10. The bar composition of any one of the preceding claims, wherein the bar composition comprises 0.00001 to 3.0% or 0.0% by weight of an amphoteric surfactant, the amphoteric surfactant being a betaine or a sultaine or a mixture thereof.

8. 8. The bar composition of claim 7, wherein betaine and / or sultaine are present and the bar composition comprises 0.001-3.5% or 0.0% by weight of taurate.

9. 10. The bar composition of any one of the preceding claims, wherein the bar composition comprises less than 9% by weight soap or 0.0% by weight soap and is substantially free of ethanol, parabens, formaldehyde donors, silicones, sulfates, glycinates and / or halogenated antimicrobial actives, where substantially free means 3.5% by weight or less of the total weight of the bar composition.

10. The bar composition comprises silicone, sulfate, C １６－１８ 10. A bar composition according to any preceding claim, substantially free of methyl ester sulfonates, glycinates, carboxylates, glutamates and / or alpha olefin sulfonates and having a zein value of < 10, where substantially free means 3.5% or less by weight of the total weight of the bar composition.

11. 10. The bar composition of any one of the preceding claims, further comprising 12-hydroxystearic acid, cetylpyridinium chloride, cetyltrimethylammonium chloride, cetyltrimethylammonium bromide, benzalkonium chloride, benzethonium chloride, cetrimide, cetrimonium chloride and / or bromide, chloroxylenol, antimicrobial lipids, antimicrobial peptides, triclosan, thymol, terpineol or mixtures thereof.

12. 10. The bar composition of any one of the preceding claims, wherein the 10% aqueous slurry has a pH of 3.9 to 4.

8.

13. a) treating said surface with i) 60 to 99% by weight of water; ii) 1 to 40% by weight of water soluble and water insoluble ingredients from the bar composition of any one of claims 1 to 12. with a bath slurry comprising: b) washing said slurry from said surface.

1. A method for reducing the presence of both gram-negative and gram-positive antimicrobial agents on a surface in need of antimicrobial reduction, comprising: the soluble and insoluble components make up 20-40% by weight of the total component weight in a slurry including the soluble components of step a), and further wherein the bar composition has antimicrobial activity in a 10% slurry, the antimicrobial activity having a Log β value against E. coli ATCC 10536 and S. aureus ATCC 6538 of at least 1.0 after 15 seconds of contact. １０ and said bar slurry has a pH of 2.9 to 5.

2.

14. The method of claim 13, wherein the surface is hair, skin or an inanimate object.

15. In a 10% aqueous slurry, a Log ELISA for E. coli ATCC 10536 and S. aureus ATCC 6538 of at least 1.0 after 15 seconds of contact on the skin, preferably at least 2.0 after 25 seconds of contact on the skin, and most preferably at least 3.0 after 35 seconds of contact on the skin. １０ Use of the bar composition of any one of claims 1 to 12 to provide a reduction.

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