Antimicrobial compositions comprising micro-moving metals

Abstract

The present invention discloses a composition comprising: (i) a composite antimicrobial particulate material comprising a micro-moving metal embedded in a water-insoluble inorganic carrier; and (ii) at least one of thymol or terpineol or a mixture thereof. The composition may be used to disinfect a living or inliving surface by reducing the bacterial count of at least one gram-positive or gram-negative bacterium on the surface by 1 to 5 log over a contact time of 10 to 30 seconds.

Description

[0001] This application is a divisional application of the Chinese invention patent application with application date of November 8, 2017, application number 201780078896.7, and invention name “Antimicrobial composition containing micro-dynamic metal”. Technical Field

[0002] The present invention relates to antimicrobial compositions containing microdynamic metals. In particular, the present invention relates to personal wash compositions for rapid disinfection of animate and inanimate surfaces. Background Art

[0003] There is an ever-increasing demand for antimicrobial cleansing compositions, such as personal wash products, such as soap bars, body wash compositions, and hand wash compositions. Antimicrobial cleansing compositions containing micromobility metals such as silver, copper, or zinc are effective against a variety of bacteria. Silver is the most widely used.

[0004] WO 2010 / 046238 A1 (Unilever) discloses antimicrobial personal care compositions containing thymol and terpineol.

[0005] WO2016020168A1 (Unilever) discloses the preparation of antimicrobial metal nanoparticles immobilized in an inorganic porous material and a personal care composition containing these particles. The antimicrobial particle composition comprises 0.05 to 3% by weight of the antimicrobial metal particles, with the balance being an inorganic carrier.

[0006] However, consumers are demanding more and more effective sustainable products. Summary of the Invention

[0007] It has been determined that compositions, more particularly personal wash compositions comprising a micromobile metal and at least one of thymol or terpineol, exhibit significant antibacterial activity. The metal is desirably in the form of a composite particulate material wherein the metal is embedded in a water-insoluble inorganic carrier such as calcium carbonate.

[0008] The presence of this form of the micromotion metal allows the formulation of compositions containing significantly small amounts of micromotion metal. Typically, such metals are contained in amounts of the order of ppm (parts per million). However, it is still desirable to formulate compositions containing as little of such metal as possible. The expression "as little as possible" is context-dependent, since in the case of personal wash compositions applied to human skin, the metal content needs to be as little as possible in the literal sense, but on the other hand, there are compositions for disinfecting inanimate surfaces (such as tabletops and tiles) in which greater amounts of the metal (in practical terms) may be permissible and desirable, so that even a slight reduction relative to conventional products, while keeping the actual metal content high enough for effective disinfection, may still be considered desirable. A surprising effect is that, despite the reduced amount of micromotion metal, the compositions according to the invention provide a rapid disinfecting action, which is usually measured and reported in terms of logarithmic reduction of bacteria. Such an effect has been observed, in particular in the case of personal wash compositions, in particular soap bars.

[0009] According to a first aspect, a composition as claimed in claim 1 is disclosed.

[0010] Any feature of one aspect of the present invention can be used in any other aspect of the present invention. The word "comprising" is intended to mean "including", but not necessarily "consisting of" or "composed of". In other words, the steps or options listed do not need to be exhaustive. Unless in the operating examples and comparative examples, or when otherwise clearly indicated, all numbers in this specification representing the amount of material or reaction conditions, material physical properties and / or uses should be understood to be modified by the word "about". Numerical ranges expressed in the form of "x to y" should be understood to include x and y. When multiple preferred ranges are described in the form of "x to y" for a particular feature, it should be understood that all ranges combining different endpoints are also intended.

[0011] Unless indicated to the contrary, references to the terms weight % or % by weight are to be interpreted as meaning the % of the relevant ingredient by weight of the composition.

[0012] The present invention also relates to the following items:

[0013] 1. A composition comprising:

[0014] (i) a composite antimicrobial particulate material comprising a microdynamic metal embedded in a water-insoluble inorganic carrier; and,

[0015] (ii) at least one of thymol or terpineol or a mixture thereof.

[0016] 2. The composition of item 1, wherein the inorganic carrier is at least one of titanium oxide, magnesium oxide, aluminum oxide, silicon oxide, calcium oxide, barium oxide, calcium hydroxyapatite, calcium carbonate, calcium magnesium carbonate, sheet silicate, zeolite, clay or bentonite.

[0017] 3. The composition of claim 2, wherein the inorganic carrier is calcium carbonate.

[0018] 4. A composition as described in any one of items 1 to 3, wherein the amount of microdynamic metal in the antimicrobial particulate material is from 0.1% to 10% by weight of the particulate material.

[0019] 5. The composition of any one of items 1 to 4, wherein the fringing metal is copper or silver.

[0020] 6. The composition of any one of items 1 to 5, comprising 0.0001 to 5% by weight of the thymol or terpineol.

[0021] 7. The composition of any one of items 1 to 6, wherein the composition comprises thymol and terpineol.

[0022] 8. The composition of any one of items 1 to 7, wherein the weight / weight ratio of the amount of thymol to the amount of terpineol is from 1:0.1 to 1:10.

[0023] 9. The composition of item 8, wherein the ratio is 1:0.5 to 1:2.

[0024] 10. The composition of any one of items 1 to 9, wherein the composition comprises the composite antimicrobial particles in an amount equivalent to 0.00005 to 2% by weight of the faltering metal.

[0025] 11. The composition of any one of items 1 to 10, wherein the composition is a personal wash composition.

[0026] 12. The composition of item 11, wherein the personal wash composition comprises at least 10% by weight of C8-C 22 Fatty acid soap.

[0027] 13. Use of a composition according to any one of items 1 to 12 for disinfecting a surface by reducing the bacterial count of at least one Gram-positive or Gram-negative bacterium on an animate or inanimate surface by 1 to 5 log within a contact time of 10 to 30 seconds, wherein the use is non-therapeutic.

[0028] 14. A non-therapeutic method of disinfecting an animate or inanimate surface by contacting the surface with the composition of any one of items 1 to 12 to reduce the bacterial count of at least one Gram-positive or Gram-negative bacterium on the surface by 1 to 5 logs within a contact time of 10 to 30 seconds. DETAILED DESCRIPTION

[0029] Although many antimicrobial disinfecting compositions are commercially available and some are reported in the literature, due to the emergence of bacterial resistance and the emergence of newer strains of virulent microorganisms, there is a need for more effective products.

[0030] Silver is known for its microkinetic effect. This effect is the ability of certain metals, in small amounts, to exert a lethal effect on bacterial cells. Some of these metals and their compounds possess the ability to alter and kill microbial cells in unique ways. Microkinetic metals, such as silver and copper, have long been used to disinfect and sanitize various surfaces, but home care and personal care compositions are at the top of the list.

[0031] As used herein, personal cleansing compositions are meant to include compositions for cleaning and disinfecting localized areas, such as the skin and / or hair of mammals, particularly humans. Such compositions can be categorized as leave-on or rinse-off, and include any product that is applied to the human body to additionally improve appearance, cleanliness, odor control, or general aesthetics. More preferably, it is a rinse-off product.

[0032] As used herein, "skin" is meant to include skin on the face and body (e.g., neck, chest, back, arms, underarms, hands, legs, buttocks, and scalp). The compositions of the present invention are also relevant for use on any other keratinous substrate of the human body other than skin, such as hair, in which case the product can be formulated with the specific purpose of providing disinfection and cleansing.

[0033] The composition according to the invention

[0034] According to a first aspect, there is disclosed a composition comprising:

[0035] (i) a composite antimicrobial particulate material comprising a microdynamic metal embedded in a water-insoluble inorganic carrier; and,

[0036] (ii) at least one of thymol or terpineol or a mixture thereof.

[0037] Composite antimicrobial microparticle materials

[0038] Preferably, the inorganic support is at least one of titanium oxide, magnesium oxide, aluminum oxide, silicon oxide, calcium oxide, barium oxide, calcium hydroxyapatite, calcium carbonate, calcium magnesium carbonate, sheet silicate, zeolite, clay, or bentonite. More preferably, the inorganic support is composed of aggregates of nanoplate-like structures having a width of 20 to 100 nm, preferably 40 to 60 nm. Further preferably, the inorganic support is a porous material having nano- or microstructured components. The particle size of the inorganic support is preferably 1 to 10 μm. A particularly preferred inorganic support is calcium carbonate. Other preferred supports are titanium oxide, magnesium hydroxide, and zinc oxide.

[0039] Preferably, the amount of micro-motion metal included in the antimicrobial granular material is from 0.1 to 10% by weight, based on the weight of the granular material. In this case, the balance may be more or less composed of inorganic carrier. Appropriate process conditions and stoichiometric amounts of starting materials are required to ensure that the antimicrobial granules contain from 0.1 to 10% by weight of micro-motion metal, based on the weight of the granular material. The process steps and conditions disclosed in WO16020168A1 (Unilever) can be, and are preferably, used to prepare the composite antimicrobial granular material.

[0040] The method for preparing the composite antimicrobial granular material comprises the following steps:

[0041] An aqueous dispersion of a water-insoluble inorganic carrier having a particle size in the range of 1 to 10 μm is prepared. The dispersion contains 1 to 5 wt. % (based on the weight of the dispersion) of the carrier.

[0042] Separately, an aqueous solution of a reducing agent is prepared, wherein the concentration of the reducing agent in the solution is 10 to 30% by weight.

[0043] The dispersion and solution are mixed. Thereafter, the mixture is heated to 70° C. to 90° C. At this stage, the water-soluble salt of the micro-dynamic metal is added to the heated mixture.

[0044] Preferably, the reducing agent is sodium acetate, sodium oxalate, trisodium citrate or disodium EDTA.

[0045] It is particularly preferred that the micro-motion metal is copper or silver, more particularly silver. Gold is also an alternative, but less preferred due to its price. Preferably, the composition according to the invention comprises an amount of composite antimicrobial particles corresponding to 0.001 to 2% by weight of micro-motion metal. For example, if it is desired that the composition should contain 0.5% by weight of silver (= 0.5 g of silver in 100 g of composition), an amount of composite particulate material containing 0.5 g of silver is included in the composition. This amount can vary depending on the solvent content in the particulate material.

[0046] Silver is particularly preferred. In ionic form, it can be present as a salt or any compound in any suitable oxidation state. Preferably, the composition according to the invention contains the composite antimicrobial particles in an amount corresponding to 0.001 to 2% by weight of the micro-mobility metal. When the metal is present in the form of a compound, such as silver in the form of silver acetate, an amount of the compound is included so that the active metal content is within the broad and preferred ranges already indicated.

[0047] Preferably, the metal, such as silver, is present in the form of a compound, such as a silver(I) compound, but may also be in the form of particles, such as silver nanoparticles.

[0048] The silver(I) compound is one or more water-soluble silver(I) compounds having a silver ion solubility of at least 1.0×10 ” 4 mol / L (in water at 25 degrees Celsius). As referred to herein, silver ion solubility is a value derived from the solubility product (Ksp) in water at 25 degrees Celsius, a well-known parameter reported in many sources. More specifically, silver ion solubility [Ag+], a value given in mol / L, can be calculated using the following formula: [Ag+] = (Ksp·x) (1 / (x+1)) , where Ksp is the solubility product of the compound of interest in water at 25 degrees Celsius and x represents the number of moles of silver ions per mole of compound. 4 Silver (I) compounds with a silver ion solubility of 100 mol / L are suitable for use in the present invention. Table 1 shows the silver ion solubility values ​​of various silver compounds:

[0049] Table 1

[0050]

[0051]

[0052] Preferably, when silver is present in the form of a compound, the compound is selected from silver oxide, silver nitrate, silver acetate, silver sulfate, silver benzoate, silver salicylate, silver carbonate, silver citrate or silver phosphate. In particularly preferred compositions, the silver (I) compound is silver oxide.

[0053] Thymol / Terpineol

[0054] In addition to the composite antimicrobial particulate material, the composition according to the present invention comprises from 0.0001 to 5% by weight of at least one of thymol or terpineol.

[0055] Preferably, the composition according to the present invention comprises thymol and terpineol, i.e. a combination of the two. In this case, preferably the weight / weight ratio of thymol to terpineol is from 1:0.1 to 1:10. More preferably, the ratio is from 1:0.5 to 1:2.

[0056] When thymol is present alone or in combination with terpineol, it is preferred that the amount of thymol is 0.01 to 2 wt%, more preferably 0.01 to 1 wt%, even more preferably 0.01 to 0.5 wt%, and even more preferably 0.01 to 0.05 wt%. Thymol is effective at lower doses, so higher doses can be used only when necessary.

[0057] The shortcoming of thymol is its smell, which may appear to be unpleasant to some individuals, but such higher dosages can be used for compositions where sensory aspects are not important or in the case of compositions that allow the inclusion of suitable odor masking agents. Preferably, thymol is used in a purified form. As an alternative to thymol, thyme oil or thyme extract comprising thymol can be used, while ensuring that sufficient / desired amounts of thymol are present therein. Thyme oil or thyme extract are available from thyme plants. Thyme plants refer to plants belonging to the genus Thymus, and include but are not limited to following species: silver spotted thyme (Thymus vulgaris), thyme (Thymus zygis), Thymus satureoides, mastic thyme (Thymus mastichina), Thymus broussonetti, Thymus maroccanus, Thymus pallidus, Thymus algeriensis, red thyme (Thymus serpyllum), Thymus pulegoide and lemon thyme (Thymus citriodorus). The isomers of thymol (carvacrol) can also be used. Alternatively, but less preferably, any derivative of thymol having similar thymol properties can also be used.

[0058]

[0059] In addition to or in place of thymol, the composition according to the present invention comprises terpineol. When terpineol is present alone or in combination with thymol, the amount of terpineol is preferably 0.01 to 2% by weight, more preferably 0.01 to 1% by weight, even more preferably 0.01 to 0.5% by weight, and even more preferably 0.01 to 0.05% by weight. Terpineol is effective at lower doses, so higher doses can be used only when necessary.

[0060] Like thymol, a disadvantage of terpineol is its odor, which may appear unpleasant to some individuals, but such higher doses may be used in compositions where sensory aspects are unimportant or where inclusion of a suitable odor masking agent is permitted. Preferably, terpineol is used in purified form.

[0061] The structure of terpineol is as follows:

[0062]

[0063] Alternatively, but less preferably, pine oil containing the desired amount of terpineol may be used instead of purified terpineol.

[0064] Finer metals, particularly silver, are effective primarily due to their ability to influence the permeability of bacterial membranes and generate reactive oxygen species. Silver ions are considered reactive species. Therefore, if sufficient quantities of these ions are generated quickly and efficiently, they can lead to a rapid reduction in viable bacterial counts on surfaces contaminated with live bacteria.

[0065] The micro-mobile metal, such as silver, embedded in an inorganic carrier, together with thymol (or terpineol or both) provides a faster-acting antibacterial effect while allowing a significant reduction in the micro-mobile metal content that would otherwise be required. The composition according to the present invention is effective against at least one of Gram-positive and Gram-negative bacteria. More preferred compositions provide a broad-spectrum antibacterial effect, meaning that they are effective against both Gram-positive and Gram-negative bacteria.

[0066] Without wishing to be bound by theory, it is believed that the inorganic carrier ensures the release of an effective amount of the marginally mobile metal ions. Such ions, together with at least one of thymol and terpineol, preferably both, act synergistically to provide a 1 to 5 log reduction in bacterial counts on animate or inanimate surfaces within a contact time of 10 to 30 seconds.

[0067] Uses and methods of compositions

[0068] According to a second aspect, there is disclosed the use of a composition according to the first aspect for disinfecting a surface by reducing the bacterial count of at least one Gram-positive or Gram-negative bacterium on an animate or inanimate surface by 1 to 5 log within a contact time of 10 to 30 seconds.

[0069] As used herein, the term "log reduction" refers to a 10-fold or 90% reduction in the number of viable microorganisms. A "2 log" reduction refers to a 9.9% reduction in the number of viable bacteria. A "4 log" reduction refers to a 99.99% reduction in the number of viable bacteria.

[0070] Preferably, the Gram-positive bacterium is Staphylococcus aureus. Preferably, the Gram-negative bacterium is Escherichia coli. In one aspect, the use is non-therapeutic in nature. In another aspect, it is therapeutic in nature. The distinction is within the knowledge of those skilled in the art.

[0071] According to a third aspect, there is disclosed a method of disinfecting an animate or inanimate surface by contacting the surface with a composition according to the first aspect to reduce the bacterial count of at least one Gram-positive or Gram-negative bacteria on the surface by 1 to 5 logs within a contact time of 10 to 30 seconds.

[0072] Preferably, the Gram-positive bacteria is Staphylococcus aureus. Preferably, the Gram-negative bacteria is Escherichia coli. In one aspect, the use is non-therapeutic in nature. In another aspect, it is therapeutic in nature. The distinction is within the knowledge of those skilled in the art. Generally, treatment refers to any treatment intended to cure, alleviate, eliminate or alleviate the symptoms of any disorder or dysfunction of the body, or to prevent or reduce the likelihood of infection of any disorder or dysfunction of the body. In the case of cosmetic compositions such as soaps and shampoos, the term non-therapeutic refers to the cosmetic use or method.

[0073] The term animate surface refers to any surface of a living animal, especially a mammal, more especially a human. Examples include skin, scalp, teeth and hair.

[0074] The term inanimate surface includes non-living surfaces such as tabletops, tiles, floors, wooden, ceramic or plastic surfaces.

[0075] Details of the composition according to the invention

[0076] In one aspect, the composition according to the present invention is a home care composition. Non-limiting examples include laundry detergents, liquid laundry detergents, fabric conditioners, floor cleaners, toilet cleaning compositions, dishwashing compositions and other hard surface cleaning compositions.

[0077] Alternatively, the composition is a personal care composition or a personal cleansing composition.

[0078] Depending on the type and intended purpose of the composition, they will contain other ingredients normally present in such compositions.Preferably, the personal care composition is a cosmetic composition.

[0079] In one aspect, cosmetic compositions are leave-on. They are intended to be applied to the skin and remain in contact with it for a prolonged period of time. Leave-on compositions preferably refer to compositions that are applied to a surface (e.g., skin) without the subsequent step of washing the surface to achieve removal of the composition after application. Examples include skin creams, lotions, and hair creams.

[0080] Alternatively, the cosmetic compositions are of the wash off or rinse off type, which, as the name implies, are those compositions which need to be rinsed off with water. Examples include hand soaps, soap bars and shampoos.

[0081] All cosmetic compositions comprise a cosmetically acceptable base, which is preferably a cream, lotion, gel or emulsion. The cosmetically acceptable base typically comprises 10-99.9%, preferably 50-99%, by weight of the composition and may, in the absence of other personal care adjuvants, form the balance of the composition.

[0082] Personal care compositions (leave-on type) can be prepared using various cosmetically acceptable emulsifying or non-emulsifying systems and carriers. A very suitable base is a cream. Vanishing cream is particularly preferred. The vanishing cream base typically contains 5 to 25% fatty acids and 0.1 to 10% soap. The vanishing cream base provides the skin with a highly valued matt feel. C12 to C20 fatty acids are particularly preferred in the vanishing cream base, and C14 to C18 fatty acids are further more preferred. The fatty acids in the composition are more preferably present in an amount of 5-20% by weight of the composition. The soap in the vanishing cream base includes alkali metal salts of fatty acids, such as sodium or potassium salts, and most preferably potassium stearate.

[0083] A particularly suitable cosmetically acceptable base is a base comprising a water-in-oil emulsion comprising silicone oil as the continuous phase. The water-in-oil emulsion preferably comprises a cross-linked silicone elastomer blend.

[0084] Silicone elastomer blends are included in water-in-oil emulsions and can be used as cosmetics for the preparation of cosmetic compositions. Although silicone fluids can be used, cross-linked silicone elastomers are particularly preferred. Compared with silicone fluid polymers, the physical properties of elastomers generally depend on the number of crosslinks, rather than molecular weight. The ability of silicone elastomers to swell makes them ideal thickeners for oil phases. When applied to skin or hair, elastomers have a very smooth and soft feel. They can also be used as delivery agents for fragrances, vitamins, and other additives in cosmetic compositions.

[0085] The cosmetic composition may preferably comprise 0.1 to 5% by weight of niacinamide or a derivative thereof. In addition to niacinamide, other well-known skin lightening agents such as aloe vera extract, ammonium lactate, arbutin, azelaic acid and kojic acid may also be included.

[0086] Additionally, the composition may include a sunscreen. Any sunscreen that can be included in a matrix may be included. Both UVA and UVB sunscreens are preferred.

[0087] Preservatives may also be included in the composition to protect against potentially harmful microorganisms. Traditional preservatives suitable for use in the compositions of the present invention are alkyl esters of p-hydroxybenzoic acid. Other preservatives that have recently come into use include hydantoin derivatives, propionates, and various quaternary ammonium compounds.

[0088] Various other optional materials may be further included in the composition. These may include: antimicrobial agents such as 2-hydroxy-4,2',4'-trichlorodiphenyl ether (triclosan), 2,6-dimethyl-4-hydroxychlorobenzene, and 3,4,4'-trichlorocarbanilide; abrasive and exfoliating particles such as polyethylene and silica or alumina; cooling agents such as menthol; skin soothing agents such as aloe vera; and coloring agents.

[0089] In addition, the composition may also contain opacifiers and pearlescent agents, such as glycol distearate, titanium dioxide or 621 (styrene / acrylate copolymer); all of which can be used to enhance the appearance or performance of the product.

[0090] When the composition is in the form of a hand sanitizer, the cosmetically acceptable base may comprise an alcohol and water. The most preferred alcohols are ethanol and isopropyl alcohol. Even mixtures of two or more alcohols may be preferably used in the hand sanitizer composition. The amount of alcohol is preferably 50-95%, more preferably 60-80%, and most preferably 65-80%, by weight of the hand sanitizer composition.

[0091] The compositions of the present invention may contain a wide variety of other optional components. The CTFA Personal Care Ingredient Handbook, Second Edition, 1992, describes a wide variety of non-limiting personal care and pharmaceutical ingredients commonly used in the skin care industry.

[0092] surfactants

[0093] Personal cleansing compositions can contain a matrix of one or more surfactants for basic cleaning action. The surfactant can be of any type, such as anionic, cationic, nonionic, amphoteric or zwitterionic, and can be selected based on the end use. Anionic surfactants are most preferred because they provide good cleaning action, and they are commonly used in various cleansing compositions. Anionic surfactants can be soap-based surfactants, which are sodium / potassium salts of long-chain fatty acids.

[0094] Preferred cleansing compositions contain 5-85% by weight surfactant, more preferably 10-70% by weight surfactant. The type and total amount of surfactant will depend on the intended purpose of the composition. For example, if the composition is a soap bar, it will primarily contain fatty acid soaps (alkali metal salts of fatty acids); if the composition is a mild cleansing bar, it will primarily contain fatty acyl isethionate surfactants. Similarly, shampoos contain mostly sodium alkyl sulfate or sodium alkyl ether sulfate. Body washes typically contain sodium lauryl ether sulfate and betaine.

[0095] Typically, the composition contains a mixture of different types of surfactants. The anionic surfactant can be, for example, an aliphatic sulfonate, such as a primary alkane (e.g., C8-C22) sulfonate, a primary alkane (e.g., C8-C22) disulfonate, a C8-C22 olefin sulfonate, a C8-C22 hydroxyalkyl sulfonate, or an alkyl glyceryl ether sulfonate (AGS); or an aromatic sulfonate, such as an alkylbenzene sulfonate. α-olefin sulfonates are also suitable as anionic surfactants. The anion can also be an alkyl sulfate (e.g., C12-C18 alkyl sulfate), in particular a primary alcohol sulfate or an alkyl ether sulfate (including alkyl glyceryl ether sulfate). The anionic surfactant can also be a sulfonated fatty acid, such as α-sulfonated tallow fatty acid, a sulfonated fatty acid ester, such as α-sulfonated methyl tallowate, or a mixture thereof. Anionic surfactants can also be alkyl sulfosuccinates (including mono- and dialkyl, such as C6-C22 sulfosuccinates); alkyl and acyl taurates, alkyl and acyl sarcosinates, sulfoacetates, C8-C22 alkyl phosphates and phosphates, alkyl phosphates and alkoxyalkyl phosphates, acyl lactates or lactylates, C8-C2, monoalkyl succinates and maleates, sulfoacetates, and acyl isethionates. Another class of anionic surfactants are C8 to C20 alkyl ethoxy (1 to 20 EO) carboxylates. Yet another class of suitable anionic surfactants are C8-C18 acyl isethionates. These esters are prepared by reacting an alkali metal isethionate with mixed aliphatic fatty acids having 6 to 18 carbon atoms and an iodine value of less than 20. At least 75% of the mixed fatty acids have 12 to 18 carbon atoms, and up to 25% have 6 to 10 carbon atoms. The alkyl ether sulfates, alkyl ether sulfosuccinates, alkyl ether phosphates and alkyl ether carboxylic acids and their salts may contain 1 to 20 ethylene oxide or propylene oxide units per molecule.

[0096] It is particularly preferred that the composition of the present invention is a personal wash composition. More particularly, it is a soap bar or liquid soap composition. Bars are typically used for bathing, while liquid soap can be used for bathing as well as washing hands. Preferably, the personal wash composition comprises at least 10% by weight of C8 to C 22 Fatty acid soap.

[0097] These forms contain a major portion of fatty acid soap as the anionic surfactant.

[0098] The term "fatty acid soap", or more simply "soap", is used herein in its general sense. Reference to fatty acid soap refers to the neutralized form of the fatty acid. Preferably, the fatty acid from which the soap is derived is substantially completely neutralized when forming the fatty acid soap, i.e., at least 95%, more particularly at least 98%, of the fatty acid groups have been neutralized. The term "soap" is used herein to refer to the alkali metal or alkanolammonium salts of aliphatic, alkane or alkene monocarboxylic acids, typically derived from natural triglycerides. Sodium, potassium, magnesium, mono-, di- and triethanolammonium cations or combinations thereof are most suitable. Blends of fatty acids are typically used from which the blend of fatty acid soaps is prepared. The term "soap" refers to sodium, potassium, magnesium, mono-, di- and triethanolammonium cations or combinations thereof. Typically, sodium soap is used in the compositions of the present invention, but the soap content up to 15% may be some other soap form, such as potassium, magnesium or triethanolamine soap.

[0099] A detailed description of soaps and other surfactants that can be used can be found in "Surface Active Agents and Detergents" by Schwartz, Perry and Berch (Volumes I and II).

[0100] Soap manufacturing

[0101] Soap bars / tablets can be prepared using manufacturing techniques described in the literature and known in the art for making soap bars. Examples of the types of manufacturing processes that can be used are given in Soap Technology for the 1990s (edited by Luis Spitz, American Oil Chemist Society Champaign, Illinois, 1990). These generally include: melt forming, extrusion / stamping, and extrusion, tempering, and cutting.

[0102] The present invention will now be explained in detail with reference to the following non-limiting examples.

[0103] Example

[0104] Example 1

[0105] Some soap bars were prepared by a standard ploughshare mixing route. The compositions were coded to distinguish them based on their formulation.

[0106] Soap compositions A and B (see Table 3) are not within the scope of the present invention. Soap composition 1 is according to the present invention. Only one composition contains antimicrobial particulate material. The formulations do not differ from each other with respect to all other ingredients and their % by weight.

[0107] The composite antimicrobial granular material was prepared as follows:

[0108] 100 g of porous calcium carbonate (fixative) was prepared by mixing 147 g of calcium chloride with 106 g of sodium carbonate under constant stirring for 5 hours at 10° C. The slurry was aged for 5 hours, filtered, washed with deionized water and air dried.

[0109] 400 mg of the porous calcium carbonate thus prepared was dispersed in 10 ml of water and mixed with 4 ml of a 1 wt% aqueous solution of trisodium citrate. The mixture was heated to 80°C, and then 0.25 ml of freshly prepared 2% silver nitrate was added. The mixture was stirred at 300 rpm for 20 minutes. The mixture was filtered to separate the air-dried particles. This method yielded a composite antimicrobial particulate material containing calcium carbonate and metallic silver (as nanoparticles), wherein the silver was embedded in the calcium carbonate as a carrier. The size of the silver nanoparticles was 5 to 50 nm.

[0110] These particles were included in soap composition 1. For comparative analysis, soap bars containing silver-DTPA were prepared. These compositions did not contain the antimicrobial particles present in composition 1. The compositions of all soap bars (both those falling within the scope of the present invention and those falling outside the scope of the present invention) are shown in Table 2:

[0111] Table 2

[0112]

[0113] Note 1: DTPA stands for diethylenetriaminepentaacetic acid

[0114] Note 2: (*) Each soap bar contains 5 ppm silver (equivalent to 0.0005 wt% actual silver, based on the total weight of each bar)

[0115] Note 3: (**) Each soap bar contains 1 ppm silver (equivalent to 0.0001 wt% actual silver, based on the total weight of each bar)

[0116] program:

[0117] A working test solution (aqueous) of each composition was prepared immediately before use. Tests were performed in duplicate to minimize procedural / human error.

[0118] The soap bar was finely ground along its length to give approximately 24 g of ground wood shavings. Sample test solutions (8 w / v aqueous) were prepared from the ground wood shavings using sterile water. The ground wood shavings were completely dissolved in the water by warming the solution to facilitate dissolution.

[0119] Thereafter, 10 ml aliquots of the working test solution were dispensed into separate approximately 50 mL sterile vials, and each vial was kept in a water bath maintained at 40°C for five minutes.

[0120] Sterile test tubes containing tryptic soy broth were inoculated from lyophilized vials containing Escherichia coli and Staphylococcus aureus. The cultures were incubated at 35 ± 2°C for 23 ± 1 hours. The broth cultures were inoculated onto the surface of tryptic soy agar contained in petri dishes and incubated at 35 ± 2°C for 23 ± 1 hours. This resulted in a lawn of each bacterium on the surface of the solid medium, and growth from these was used to prepare the challenge suspension. The purity of each broth culture was verified by preparing an isolated streak on tryptic soy agar and incubating at 35 ± 2°C.

[0121] 20 ml vials each containing 10 ml of product test solution were used for testing.

[0122] The contents of each vial were stirred in a water bath maintained at 40 ± 1°C. A 0.1 ml aliquot of the challenge suspension was transferred to each vial containing the test solution (10 0 dilution) and mix with it. Expose the challenge suspension to the product test solution at 40 ± 1 ° C for 30 seconds using a calibrated minute / second timer. The calibrated minute / second timer is started within ± 1 second of the addition of the challenge suspension. After the exposure time (s) has elapsed, transfer a 1.0 mL aliquot from the vial containing the product test solution / challenge suspension to a test tube containing 9.0 mL of D / E or Butterfield's with a neutralizer (10 -1 dilution) and mix in a vortex mixer. Another 10-fold dilution (e.g., 10 -2 , 10 -3 , and 10 -4 ) Prepare in d / E or Butterfield's, using a suitable mixer, the neutralizer is mixed thoroughly. Using TSA and the neutralizer, duplicate 1.0 ml and / or 0.1 ml aliquots are plated, resulting in, for example, 10 -1 , 10 -2 , 10 -3 , 10 -4 , and 10 -5 The final plating dilution of 1% was added. The plates were incubated at 35±2°C for approximately 24 hours, or until sufficient growth was observed. Three replicates of the above procedure were performed, each using independently prepared challenge suspensions and product test solutions.

[0123] After incubation, count the colonies on the plates. Counts within the range of 30 to 300 CFU are preferentially used to calculate the data. If counts within this range are not observed, use those plates with colony counts closest to this range.

[0124] Table 3 contains a summary of the observations.

[0125] Table 3

[0126]

[0127] The data in Table 3 show the following:

[0128] Compared to compositions A and B, soap composition 1 showed superior performance.

[0129] At the end of 10 seconds, composition 1 caused a significantly greater reduction (statistically significant) in S. aureus and E. coli, despite the fact that composition 1 effectively contained only one-fifth the amount of silver compared to compositions A and B (see Table 2).

[0130] On the other hand, at 30 seconds, the log reduction in S. aureus provided by Composition 1 was significantly greater than the reduction caused by the composition without the composite antimicrobial particulate material.

[0131] Although in the case of E. coli it was observed that even compositions outside the scope of the present invention brought about a reduction of more than 5 log in the viable count of bacteria, the important difference was that composition 1 contained only 1 / 5 the amount of silver compared to compositions A and B.

Claims

1. A soap bar composition comprising: (i) a composite antimicrobial particulate material comprising a microdynamic metal embedded in a water-insoluble inorganic carrier; and, (ii) thymol and terpineol; wherein thymol is present at 0.01 to 0.05%; wherein terpineol is present at 0.01 to 0.05%; wherein the composition comprises at least 10 wt% of C8-C 22 fatty acid soaps; and wherein the composition is a personal wash composition.

2. The composition of claim 1, wherein the inorganic carrier is at least one of titanium oxide, magnesium oxide, aluminum oxide, silicon oxide, calcium oxide, barium oxide, calcium hydroxyapatite, calcium carbonate, calcium magnesium carbonate, sheet silicate, zeolite, clay or bentonite.

3. The composition of claim 2, wherein the inorganic carrier is calcium carbonate.

4. A composition according to any one of claims 1 to 3, wherein the amount of falconet metal in the antimicrobial particulate material is from 0.1% to 10% by weight of the particulate material.

5. The composition of any one of claims 1 to 4, wherein the fringing metal is copper or silver.

6. A composition as claimed in any one of the preceding claims, wherein the weight / weight ratio of the amount of thymol to the amount of terpineol is from 1 :0.5 to 1 :

2.

7. The composition of any one of claims 1 to 6, wherein the composition comprises the composite antimicrobial particles in an amount equivalent to 0.00005 to 2% by weight of the faltering metal.

8. Use of a composition according to any one of claims 1 to 7 for disinfecting a surface by reducing the bacterial count of at least one Gram-positive or Gram-negative bacterium on an animate or inanimate surface by 1 to 5 log within a contact time of 10 to 30 seconds, wherein the use is non-therapeutic.

9. A non-therapeutic method of disinfecting an animate or inanimate surface by contacting the surface with a composition according to any one of claims 1 to 7 to reduce the bacterial count of at least one Gram-positive or Gram-negative bacteria on the surface by 1 to 5 logs within a contact time of 10 to 30 seconds.

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