Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q17/00—Barrier preparations; Preparations brought into direct contact with the skin for affording protection against external influences, e.g. sunlight, X-rays or other harmful rays, corrosive materials, bacteria or insect stings
  • A61Q17/005—Antimicrobial preparations
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
  • A61K8/33—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing oxygen
  • A61K8/34—Alcohols
  • A61K8/347—Phenols
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
  • A61K8/40—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing nitrogen
  • A61K8/44—Aminocarboxylic acids or derivatives thereof, e.g. aminocarboxylic acids containing sulfur; Salts; Esters or N-acylated derivatives thereof
  • A61K8/442—Aminocarboxylic acids or derivatives thereof, e.g. aminocarboxylic acids containing sulfur; Salts; Esters or N-acylated derivatives thereof substituted by amido group(s)
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/30—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds
  • A61K8/46—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing sulfur
  • A61K8/463—Cosmetics or similar toiletry preparations characterised by the composition containing organic compounds containing sulfur containing sulfuric acid derivatives, e.g. sodium lauryl sulfate
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P17/00—Drugs for dermatological disorders
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61P—SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
  • A61P17/00—Drugs for dermatological disorders
  • A61P17/10—Anti-acne agents
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q19/00—Preparations for care of the skin

Definitions

• the present invention relates to mild, rinse-off, personal cleansing compositions which provide enhanced antimicrobial effectiveness.
• the personal cleansing compositions of the invention provide previously unseen residual effectiveness against transient Gram negative bacteria.
• Resident bacteria are Gram positive bacteria which are established as permanent microcolonies on the surface and outermost layers of the skin and play an important, helpful role in preventing the colonization of other, more harmful bacteria and fungi.
• Transient bacteria are bacteria which are not part of the normal resident flora of the skin, but can be deposited when airborne contaminated material lands on the skin or when contaminated material is brought into physical contact with it.
• Transient bacteria are typically divided into two subclasses: Gram positive and Gram negative.
• Gram positive bacteria include pathogens such as Staphylococcus aureus, Streptococcus pyogenes and Clostridium botulinum.
• Gram negative bacteria include pathogens such as Salmonella, Escherichia coli, Klebsiella, Haemophilus, Pseudomonas aeruginosa, Proteus and Shigella dysenteriae.
• Gram negative bacteria are generally distinguished from Gram positive by an additional protective cell membrane which generally results in the Gram negative bacteria being less susceptible to topical antibacterial actives.
• Antimicrobial cleansing products have been marketed in a variety of forms for some time. Forms include deodorant soaps, hard surface cleaners, and surgical disinfectants. These traditional rinse-off antimicrobial products have been formulated to provide bacteria removal during washing. The antimicrobial soaps have also been shown to provide a residual effectiveness against Gram positive bacteria, but limited residual effectiveness versus Gram negative bacteria. By residual effectiveness it is meant that bacteria growth on a surface is controlled for some period of time following the washing/rinsing process. Antimicrobial liquid cleansers are disclosed in U.S.
• Some of these antimicrobial products utilize high levels of alcohol and/or surfactants which have been shown to dry out and irritate skin tissues. Ideal personal cleansers should gently cleanse the skin, cause little or no irritation, and not leave the skin or hair overly dry after frequent use and preferably should provide a moisturizing benefit to the skin.
• rinse-off antimicrobial cleansing compositions which provide such mildness and such residual effectiveness versus Gram negative bacteria can be formulated by using known antimicrobial actives in combination with specific organic and/or inorganic acids as proton donating agents, and specific anionic surfactants, all of which are deposited on the skin.
• the deposited proton donating agent and anionic surfactant enhance the selected active, to provide a new level of hostility to bacteria contacting the skin.
• the present invention relates to a rinse-off antimicrobial cleansing composition
• a rinse-off antimicrobial cleansing composition comprising from about 0.001% to about 5% of an antimicrobial active; from about 1% to about 80% of an anionic surfactant; from about 0.1% to about 12% of a proton donating agent; from about 0.1% to about 30% of a deposition aid; and from about 3% to about 98.8% of water.
• the compositions of the present invention have a pH of from about 3.0 to about 6.0.
• the rinse-off antimicrobial cleansing compositions further have a Gram Negative Residual Effectiveness Index of greater than about 0.3; and a Mildness Index of greater than 0.3.
• the present invention also relates to methods for cleansing and for decreasing the spread of transient Gram negative bacteria using the rinse-off antimicrobial cleansing compositions described herein.
• the rinse-off antimicrobial cleansing compositions of the present invention are highly efficacious for cleansing surfaces, especially the skin, provide a residual antimicrobial effectiveness versus transient Gram negative bacteria and are mild to the skin.
• compositions of the present invention are used in a context whereby the composition is ultimately rinsed or washed from the treated surface, (e.g. skin or hard surfaces) either after or during the application of the product.
• antimicrobial cleansing composition means a composition suitable for application to a surface for the purpose of removing dirt, oil and the like which additionally controls the growth and viability of transient Gram negative bacteria.
• Preferred embodiments of the present invention are cleansing compositions suitable for use on the human skin.
• compositions of the present invention can also be useful for treatment of acne.
• treating acne means preventing, retarding and/or arresting the process of acne formation in mammalian skin.
• compositions of the invention can also potentially be useful for providing an essentially immediate (i.e., acute) visual improvement in skin appearance following application of the composition to the skin. More particularly, the compositions of the present invention are useful for regulating skin condition, including regulating visible and/or tactile discontinuities in skin, including but not limited to visible and/or tactile discontinuities in skin texture and/or color, more especially discontinuities associated with skin aging. Such discontinuities may be induced or caused by internal and/or external factors. Extrinsic factors include ultraviolet radiation (e.g., from sun exposure), environmental pollution, wind, heat, low humidity, harsh surfactants, abrasives, and the like. Intrinsic factors include chronological aging and other biochemical changes from within the skin.
• Regulating skin condition includes prophylactically and/or therapeutically regulating skin condition.
• prophylactically regulating skin condition includes delaying, minimizing and/or preventing visible and/or tactile discontinuities in skin.
• therapeutically regulating skin condition includes ameliorating, e.g., diminishing, minimizing and/or effacing, such discontinuities.
• Regulating skin condition involves improving skin appearance and/or feel, e.g., providing a smoother, more even appearance and/or feel.
• regulating skin condition includes regulating signs of aging.
• Regular signs of skin aging includes prophylactically regulating and/or therapeutically regulating one or more of such signs (similarly, regulating a given sign of skin aging, e.g., lines, wrinkles or pores, includes prophylactically regulating and/or therapeutically regulating that sign).
• “Signs of skin aging” include, but are not limited to, all outward visibly and tactilely perceptible manifestations as well as any other macro or micro effects due to skin aging. Such signs may be induced or caused by intrinsic factors or extrinsic factors, e.g., chronological aging and/or environmental damage.
• These signs may result from processes which include, but are not limited to, the development of textural discontinuities such as wrinkles, including both fine superficial wrinkles and coarse deep wrinkles, skin lines, crevices, bumps, large pores (e.g., associated with adnexal structures such as sweat gland ducts, sebaceous glands, or hair follicles), scaliness, flakiness and/or other forms of skin unevenness or roughness, loss of skin elasticity (loss and/or inactivation of functional skin elastin), sagging (including puffiness in the eye area and jowls), loss of skin firmness, loss of skin tightness, loss of skin recoil from deformation, discoloration (including undereye circles), blotching, sallowness, hyperpigmented skin regions such as age spots and freckles, keratoses, abnormal differentiation, hyperkeratinization, elastosis, collagen breakdown, and other histological changes in the stratum corneum, dermis, epidermis,
• the rinse-off antimicrobial cleansing compositions of the present invention comprise an antimicrobial active, an anionic surfactant, a proton donating agent, and a deposition aid. These components are selected so that the efficacy and mildness requirements hereinafter defined for the compositions herein are met. The selection of each component is necessarily dependent on the selection of each of the other components. For example, if a weak acid is selected as the proton donating agent, then in order to realize an efficacious composition, either a more biologically active (but possibly less mild) surfactant must be employed, and/or a high level of acid within the prescribed range must be used and/or a particularly efficacious active must be employed and/or a higher level of deposition aid within the prescribed range must be employed.
• a mild, but nonefficacious surfactant is employed, then a stronger acid and/or a high level of acid and/or a high level of deposition aid may be necessary to realize an efficacious composition. If a harsh surfactant is utilized, then a mildness agent may have to be utilized or a lipophilic skin moisturizer ingredient may have to be employed as the deposition aid. Guidelines for the selection of the individual components are provided herein. A. ANTIMICROBIAL ACTIVE
• the rinse-off antimicrobial cleansing compositions of the present invention comprise from about 0.001% to about 5%, preferably from about 0.01% to about 2%, more preferably from about 0.05% to about 1.5% and most preferably from about 0.1% to about 1.0% of an antimicrobial active.
• the exact amount of antibacterial active to be used in the compositions will depend on the particular active utilized since actives vary in potency. Non-cationic actives are required in order to avoid interaction with the anionic surfactants of the invention.
• non-cationic antimicrobial agents which are useful in the present invention .
• Phenethyl Alcohol o-Phenylphenol/sodium o-phenylphenol
• natural antibacterial actives are the so-called "natural" antibacterial actives, referred to as natural essential oils. These actives derive their names from their natural occurrence in plants.
• natural essential oil antibacterial actives include oils of anise, lemon, orange, rosemary, wintergreen, thyme, lavender, cloves, hops, tea tree, citronella, wheat, barley, lemongrass, cedar leaf, cedarwood, cinnamon, fleagrass, geranium, sandalwood, violet, cranberry, eucalyptus, vervain, peppermint, gum benzoin, basil, fennel, fir, balsam, menthol, ocmea origanum, Hydastis carradensis, Berberidaceae daceae, Ratanhiae and Curcuma longa.
• Also included in this class of natural essential oils are the key chemical components of the plant oils which have been found to provide the antimicrobial benefit. These chemicals include, but are not limited to anethol, catechole, camphene, thymol, eugenol, eucalyptol, ferulic acid, farnesol, hinokitiol, tropolone, limonene, menthol, methyl salicylate, thymol, terpineol, verbenone, berberine, ratanhiae extract, caryophellene oxide, citronellic acid, curcumin, nerolidol and geraniol. Additional active agents are antibacterial metal salts.
• This class generally includes salts of metals in groups 3b- 7b, 8 and 3a-5a. Specifically are the salts of aluminum, zirconium, zinc, silver, gold, copper, lanthanum, tin, mercury, bismuth, selenium, strontium, scandium, yttrium, cerium, praseodymiun, neodymium, promethum, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and mixtures thereof.
• Preferred antimicrobial agents for use herein are the broad spectrum actives selected from the group consisting of Triclosan®, Triclocarban®, Octopirox®, PCMX, ZPT, natural essential oils and their key ingredients, and mixtures thereof.
• the most preferred antimicrobial active for use in the present invention is Triclosan®.
• Liquid embodiments of the rinse-off antimicrobial cleansing compositions of the present invention comprise from about 1% to about 80%, preferably from about 3% to about 50%, and more preferably from about 5% to about 25%, based on the weight of the personal cleansing composition, of an anionic surfactant.
• Solid bar embodiments of the present invention preferably comprise from about 10% to about 70%, and more preferably from about 20% to about 60% of the anionic surfactant.
• the anionic surfactant disrupts the lipid in the cell membrane of the bacteria.
• the particular acid used herein reduces the negative charges on the cell wall of the bacteria, crosses through the cell membrane, weakened by the surfactant, and acidifies the cytoplasm of the bacteria. The antimicrobial active can then pass more easily through the weakened cell wall, and more efficiently poison the bacteria.
• Nonlimiting examples of anionic lathering surfactants useful in the compositions of the present invention are disclosed in McCutcheon's, Detergents and Emulsifiers. North American edition (1990), published by The Manufacturing Confectioner Publishing Co.; McCutcheon's, Functional Materials, North American Edition (1992); and U.S. Patent No. 3,929,678, to Laughlin et al., issued December 30, 1975, all of which are incorporated by reference.
• anionic lathering surfactants include those selected from the group consisting of alkyl and alkyl ether sulfates, sulfated monoglycerides, sulfonated olefins, alkyl aryl sulfonates, primary or secondary alkane sulfonates, alkyl sulfosuccinates, acyl taurates, acyl isethionates, alkyl glycerylether sulfonate, sulfonated methyl esters, sulfonated fatty acids, alkyl phosphates, acyl glutamates, acyl sarcosinates, alkyl sulfoacetates, acylated peptides, alkyl ether carboxylates, acyl lactylates, anionic fluorosurfactants, and mixtures thereof.
• anionic lathering surfactants include those selected from the group consisting of alkyl and alky
• Anionic surfactants for use in the cleansing compositions include alkyl and alkyl ether sulfates. These materials have the respective formulae RIO-SO3M and R ⁇ C ⁇ O) ⁇ O-SO3M, wherein R ⁇ is a saturated or unsaturated, branched or unbranched alkyl group from about 8 to about 24 carbon atoms, x is 1 to 10, and M is a water-soluble cation such as ammonium, sodium, potassium, magnesium, triethanolamine, diethanolamine and monoethanolamine.
• the alkyl sulfates are typically made by the sulfation of monohydric alcohols (having from about 8 to about 24 carbon atoms) using sulfur trioxide or other known sulfation technique.
• the alkyl ether sulfates are typically made as condensation products of ethylene oxide and monohydric alcohols (having from about 8 to about 24 carbon atoms) and then sulfated. These alcohols can be derived from fats, e.g., coconut oil or tallow, or can be synthetic. Specific examples of alkyl sulfates which may be used in the cleanser compositions are sodium, ammonium, potassium, magnesium, or TEA salts of lauryl or myristyl sulfate. Examples of alkyl ether sulfates which may be used include ammonium, sodium, magnesium, or TEA laureth-3 sulfate.
• sulfated monoglycerides of the form R 1 CO-0-CH 2 -C(OH)H-CH2-0-S0 3 M, wherein R 1 is a saturated or unsaturated, branched or unbranched alkyl group from about 8 to about 24 carbon atoms, and M is a water-soluble cation such as ammonium, sodium, potassium, magnesium, triethanolamine, diethanolamine and monoethanolamine.
• R 1 is a saturated or unsaturated, branched or unbranched alkyl group from about 8 to about 24 carbon atoms
• M is a water-soluble cation such as ammonium, sodium, potassium, magnesium, triethanolamine, diethanolamine and monoethanolamine.
• fatty acids having from about 8 to about 24 carbon atoms
• An example of a sulfated monoglyceride is sodium cocomonoglyceride sulfate.
• Suitable anionic surfactants include olefin sulfonates of the form RI SO3M, wherein R! is a mono-olefin having from about 12 to about 24 carbon atoms, and M is a water-soluble cation such as ammonium, sodium, potassium, magnesium, triethanolamine, diethanolamine and monoethanolamine.
• R! is a mono-olefin having from about 12 to about 24 carbon atoms
• M is a water-soluble cation such as ammonium, sodium, potassium, magnesium, triethanolamine, diethanolamine and monoethanolamine.
• R! is a mono-olefin having from about 12 to about 24 carbon atoms
• M is a water-soluble cation such as ammonium, sodium, potassium, magnesium, triethanolamine, diethanolamine and monoethanolamine.
• anionic surfactants are the linear alkylbenzene sulfonates of the form R ⁇ " C6H4-SO3M, wherein R* is a saturated or unsaturated, branched or unbranched alkyl group from about 8 to about 24 carbon atoms, and M is a water-soluble cation such as ammonium, sodium, potassium, magnesium, triethanolamine, diethanolamine and monoethanolamine. These are formed by the sulfonation of linear alkyl benzene with sulfur trioxide.
• An example of this anionic surfactant is sodium dodecylbenzene sulfonate.
• Still other anionic surfactants suitable for this cleansing composition include the primary or secondary alkane sulfonates of the form RISO3M, wherein R* is a saturated or unsaturated, branched or unbranched alkyl chain from about 8 to about 24 carbon atoms, and M is a water- soluble cation such as ammonium, sodium, potassium, magnesium, triethanolamine, diethanolamine and monoethanolamine.
• R* is a saturated or unsaturated, branched or unbranched alkyl chain from about 8 to about 24 carbon atoms
• M is a water- soluble cation such as ammonium, sodium, potassium, magnesium, triethanolamine, diethanolamine and monoethanolamine.
• R* is a saturated or unsaturated, branched or unbranched alkyl chain from about 8 to about 24 carbon atoms
• M is a water- soluble cation such as ammonium, sodium, potassium, magnesium, triethanolamine, diethanolamine and monoethanolamine.
• R* is
• alkyl sulfosuccinates which include disodium N-octadecylsulfosuccinamate; diammonium lauryl sulfosuccinate; tetrasodium N-(l,2- dicarboxyethyl)-N-octadecylsulfosuccinate; diamyl ester of sodium sulfosuccinic acid; dihexyl ester of sodium sulfosuccinic acid; and dioctyl esters of sodium sulfosuccinic acid.
• taurates which are based on taurine, which is also known as 2- aminoethanesulfonic acid.
• taurates include N-alkyltaurines such as the one prepared by reacting dodecylamine with sodium isethionate according to the teaching of U.S. Patent 2,658,072 which is incorporated herein by reference in its entirety.
• Other examples based of taurine include the acyl taurines formed by the reaction of n-methyl taurine with fatty acids (having from about 8 to about 24 carbon atoms).
• acyl isethionates Another class of anionic surfactants suitable for use in the cleansing composition are the acyl isethionates.
• the acyl isethionates typically have the formula RICO-O-CH2CH2SO3M wherein R' is a saturated or unsaturated, branched or unbranched alkyl group having from about 10 to about 30 carbon atoms, and M is a cation. These are typically formed by the reaction of fatty acids (having from about 8 to about 30 carbon atoms) with an alkali metal isethionate.
• Nonlimiting examples of these acyl isethionates include ammonium cocoyl isethionate, sodium cocoyl isethionate, sodium lauroyl isethionate, and mixtures thereof.
• alkylglyceryl ether sulfonates of the form Rl-OCH2-C(OH)H-CH2"S ⁇ 3M, wherein R ⁇ is a saturated or unsaturated, branched or unbranched alkyl group from about 8 to about 24 carbon atoms, and M is a water-soluble cation such as ammonium, sodium, potassium, magnesium, triethanolamine, diethanolamine and monoethanolamine.
• R ⁇ is a saturated or unsaturated, branched or unbranched alkyl group from about 8 to about 24 carbon atoms
• M is a water-soluble cation such as ammonium, sodium, potassium, magnesium, triethanolamine, diethanolamine and monoethanolamine.
• R ⁇ is a saturated or unsaturated, branched or unbranched alkyl group from about 8 to about 24 carbon atoms
• M is a water-soluble cation such as ammonium, sodium, potassium, magnesium, triethanolamine, diethanolamine and monoethanolamine.
• fatty alcohols
• anionic surfactants include the sulfonated fatty acids of the form Rl-
• R 1 is a saturated or unsaturated, branched or unbranched alkyl group from about 8 to about 24 carbon atoms.
• R 1 is a saturated or unsaturated, branched or unbranched alkyl group from about 8 to about 24 carbon atoms.
• R 1 is a saturated or unsaturated, branched or unbranched alkyl group from about 8 to about 24 carbon atoms.
• These can be formed by the sulfonation of fatty acids or alkyl methyl esters (having from about 8 to about 24 carbon atoms) with sulfur trioxide or by another known sulfonation technique. Examples include alpha sulphonated coconut fatty acid and lauryl methyl ester.
• anionic materials include phosphates such as monoalkyl, dialkyl, and trialkylphosphate salts formed by the reaction of phosphorous pentoxide with monohydric branched or unbranched alcohols having from about 8 to about 24 carbon atoms. These could also be formed by other known phosphation methods.
• An example from this class of surfactants is sodium mono or dilaurylphosphate.
• anionic materials include acyl glutamates corresponding to the formula R ⁇ CO- N(COOH)-CH2CH2-C ⁇ 2M wherein R s a saturated or unsaturated, branched or unbranched alkyl or alkenyl group of about 8 to about 24 carbon atoms, and M is a water-soluble cation.
• R s a saturated or unsaturated, branched or unbranched alkyl or alkenyl group of about 8 to about 24 carbon atoms
• M is a water-soluble cation.
• anionic materials include alkanoyl sarcosinates corresponding to the formula RlCON(CH3)-CH2CH2"C ⁇ 2M wherein R ⁇ is a saturated or unsaturated, branched or unbranched alkyl or alkenyl group of about 10 to about 20 carbon atoms, and M is a water- soluble cation.
• R ⁇ is a saturated or unsaturated, branched or unbranched alkyl or alkenyl group of about 10 to about 20 carbon atoms
• M is a water- soluble cation.
• anionic materials include alkyl ether carboxylates corresponding to the formula R1 ⁇ (OCH2CH2) x -OCH2-C ⁇ 2M wherein R ⁇ is a saturated or unsaturated, branched or unbranched alkyl or alkenyl group of about 8 to about 24 carbon atoms, x is 1 to 10, and M is a water- soluble cation.
• R ⁇ is a saturated or unsaturated, branched or unbranched alkyl or alkenyl group of about 8 to about 24 carbon atoms
• x is 1 to 10
• M is a water- soluble cation.
• anionic materials include acyl lactylates corresponding to the formula RlCO-[0- CH(CH3)-CO] x -C ⁇ 2M wherein R is a saturated or unsaturated, branched or unbranched alkyl or alkenyl group of about 8 to about 24 carbon atoms, x is 3, and M is a water-soluble cation.
• R is a saturated or unsaturated, branched or unbranched alkyl or alkenyl group of about 8 to about 24 carbon atoms
• x is 3
• M is a water-soluble cation.
• anionic materials include the carboxylates, nonlimiting examples of which include sodium lauroyl carboxylate, sodium cocoyl carboxylate, and ammonium lauroyl carboxylate.
• Anionic flourosurfactants can also be used.
• counter cation M
• the counter cation is selected from the group consisting of sodium, potassium, ammonium, monoethanolamine, diethanolamine, and triethanolamine. More preferably the counter cation is ammonium.
• the biological activity of a surfactant and the mildness of a surfactant are inversely proportional; the higher the biological activity of the surfactant, the harsher the surfactant and the lower the biological activity of the surfactant, the milder the surfactant. Whether a biologically active, but harsh surfactant or a mild, but biologically inactive surfactant is desired will, of course, depend on (or influence) the selection of the other components.
• the biological activity/mildness of a pure surfactant can measured directly via a Microtox Response Test hereinafter described in the Analytical Methods section and can be reported as a Microtox Response Index.
• pure surfactant it is meant a chemical composition consisting essentially of a single surfactant entity, wherein the entity has essentially one chain length, head group and salt counter ion. From a standpoint of high biological activity, preferred anionic surfactants of the antimicrobial cleansing compositions of the present invention have a Microtox Response Index of less that about 150, more preferably less than about 100 and most preferably less than about 50.
• preferred anionic surfactants of the antimicrobial cleansing compositions of the present invention have a Microtox Response Index of greater than about 25, more preferably greater than about 50 and most preferably greater than about 100.
• Surfactants with a Microtox Response Index ranging from about 25 to about 150 are typically moderately biologically active and moderately mild.
• the Microtox Response Index for any individual surfactant component is not a reliable measurement of biological activity or mildness.
• the Microtox Index of each individual component can be determined and the weighted average used as the Index for the mixture if all the individual components of the mixture are known. If the individual components of a mixture are not known, then the head group and chain lengths of the surfactant mixture is a better indicator of biological activity/mildness.
• the head group of the anionic surfactant be less than about 15 Angstroms, preferably less than about 10 Angstoms, and more preferably less than about 7 Angstoms.
• the "head group” is defined as the hydrophilic portion (non-hydrocarbon) of the anionic surfactant, measured from the first polar atom to the end of the molecule.
• the head group size is estimated from the Van der Waals radius of the atoms and the configuration of the surfactant molecule. Head groups with sizes less than about 7 Angstroms include sulfates, sulfonates, and phosphates.
• the head group size is greater than about 7 Angstoms, and preferably greater than about 10 Angstoms.
• Head groups with sizes greater than about 10 Angstroms include ethoxylated sulfates, glyceryl ether sulfonates, and isethionates. It is believed that as the head group size increases, more stearic hindrance at the cell wall prevents disruption by the surfactant and, thus, biological activity is decreased and mildness is increased.
• the mildness of a surfactant or mixture of surfactants can also be determined by a number of other known, conventional methods for measuring surfactant mildness.
• the Barrier Destruction Test set forth in T. J. Franz, J. Invest. Dermatol.. 1975, 64, pp. 190-195 and in U.S. Patent 4,673,525 to Small et al; issued June 16, 1987, both of which are herein incorporated by reference is a way of measuring mildness of surfactants.
• the milder the surfactant the less skin barrier that is destroyed in the barrier destruction test. Skin barrier destruction is measured by relative amount of radiolabeled water which passes from the test solution through the skin epidermis into the physiological buffer contained in the diffusate chamber.
• Surfactants having a Relative Skin Barrier Penetration Value of as close to zero as possible up to about 75 are considered mild for purposes herein.
• Surfactants having a Relative Skin Barrier Penetration Value of greater than about 75 are considered harsh for purposes herein.
• Preferred anionic surfactants are also selected, in part, based on the ability of the surfactant to deposit the antimicrobial active onto the skin.
• Surfactants for use herein must have sufficient solubility to carry the active and yet the solubility cannot be so high that the active is held in solution during use, resulting in no active being deposited to the skin. It has been found that this balance is best measured by the slope of the curve of the solubility of the antimicrobial active versus the concentration of the surfactant in water. This slope, hereafter referred to as the solubility slope, K, is determined by the test method hereinafter described in the Analytical Methods Section.
• Preferred anionic surfactants of the present invention comprise a solubility slope, K, of less than 0.60, preferably less than 0.40, more preferably less than about 0.25 and most preferably less than about 0.10.
• the rinse-off antimicrobial cleansing compositions of the present invention preferably deposit from about 0.01 ⁇ g/cm ⁇ to about 100 ⁇ g/cm ⁇ , more preferably from about 0.1 ⁇ g/cm ⁇ to about 50 ⁇ g/cm ⁇ and most preferably from about 1 ⁇ g/cm ⁇ to about 20 ⁇ g/cm ⁇ of antimicrobial active onto the skin.
• both the biological activity of the surfactant and the solubility of the particular active employed in the surfactant must be taken into account.
• compositions comprising ALS are capable of providing very effective residual antibacterial effectiveness due to its activity, even with lower levels of antibacterial active and proton donating agent.
• higher levels of active will be required as a result of the high solubility slope.
• compositions containing ALS may require the addition of co-surfactants or polymers, described herein in the Optional Ingredient Section, to achieve most preferred mildness levels for the present invention.
• Compositions comprising lower levels of active and acid can be used with higher levels of paraffin sulfonate, where the surfactant provides a larger component of residual effectiveness.
• compositions comprising lower levels of paraffin sulfonate can be combined with even higher levels of active to achieve a mild and effective composition.
• Moderate levels of active can be used with paraffin sulfonate, since its solubility index indicates that such compositions will have very high deposition of the active.
• Nonlimiting examples of preferred anionic surfactants useful herein include those selected from the group consisting of sodium and ammonium alkyl sulfates and ether sulfates having chain lengths of predominantly 12 and 14 carbon atoms, olefin sulfates having chain lengths of predominantly 14 and 16 carbon atoms, and paraffin sulfonates having chain lengths of from 13 to 17 carbon atoms, and mixtures thereof.
• ammonium and sodium lauryl sulfate is ammonium and sodium myristyl sulfate; ammonium and sodium laureth- 1, laureth-2, laureth-3, and laureth-4 sulfate; ammonium and sodium, C14-C16 olefin sulfonates; C13-C17 paraffin sulfonates, and mixtures thereof.
• Non-anionic surfactants of the group consisting of nonionic surfactants, cationic surfactants, amphoteric surfactants and mixtures thereof, have been found to actually reduce residual effectiveness benefits when used with anionic surfactants at high levels.
• the ratio of the amount of these non-anionic surfactants to the amount of anionic surfactant should be less than 1 : 1, preferably less than about 1 :2, and more preferably less than about 1 :4.
• the rinse-off antimicrobial cleansing compositions of the present invention preferably do not comprise hydrotropic sulfonates, particularly salts of terpenoids, or mono- or binuclear aromatic compounds such as sulfonates of camphor, toluene, xylene, cumene and naphthene.
• hydrotropic sulfonates particularly salts of terpenoids, or mono- or binuclear aromatic compounds such as sulfonates of camphor, toluene, xylene, cumene and naphthene.
• the rinse-off antimicrobial cleansing compositions of the present invention comprise from about 0.1% to about 12%, preferably from about 0.5% to about 10%, more preferably from about 1% to about 7.5%, and most preferably from about 2.5% to about 5%, based on the weight of the personal cleansing composition, of a proton donating agent.
• proton donating agent it is meant any acid compound or mixture thereof, which results in the presence of undissociated acid on the skin after use.
• Proton donating agents can be organic acids, including polymeric acids, mineral acids or mixtures thereof.
• Proton donating agents which are organic acids remain at least partially undissociated in the neat composition and remain so when the compositions are diluted during washing and rinsing.
• the organic acid proton donating agent must have at least one pKa value below 5.5.
• These organic proton donating agents can be added directly to the composition in the acid form or can be formed by adding the conjugate base of the desired acid and a sufficient amount of a separate acid strong enough to form the undissociated acid from the base.
• Preferred organic proton donating agents are selected based on their biological activity. This activity is represented by a Biological Activity Index, Z, which is defined as:
• the biological activity index combines the dissociation characteristics and the hydrophobicity of the acid. It is critical that the undissociated proton donating agent of the composition be deposited on the skin to reduce the negative charge on the cell wall.
• the acid's dissociation constant, pKai is indicative of the chemical's proton donating capacity relative to the pH of the medium in which it is incorporated. Since more undissociated acid is preferable in the composition, acids with higher pKa's are generally more preferred for a given product pH.
• the octanol-water partition coefficient, P represents the tendency of materials in solution to prefer either oils or water.
• Preferred organic proton donating agents of the rinse-off antimicrobial cleansing compositions of the present invention have a biological activity index greater than about 0.5, preferably greater than about 1.0, more preferably greater than about 1.5 and most preferably greater than 2.0.
• Proton donating agents which are mineral acids will not remain undissociated in the neat composition or when the compositions are diluted during washing and rinsing. Despite this, it has been found that mineral acids can be effective proton donating agents for use herein. Without being limited by theory, it is believed that the strong mineral acids, protonate the carboxylic and phosphatidyl groups in proteins of the skin cells, thereby providing in-situ undissociated acid. These proton donating agents can only be added directly to the composition in the acid form. pH
• the pH of the rinse-off antimicrobial cleansing compositions of the present invention must be adjusted to a sufficiently low level in order to either form or deposit substantial undissociated acid on the skin.
• the pH of the compositions should be adjusted and preferably buffered to have a range of from about 3.0 to about 6.0, preferably from about 3.0 to about 5.0 and more preferably from about 3.5 to about 4.5.
• a non-exclusive list of examples of organic acids which can be used as the proton donating agent are adipic acid, tartaric acid, citric acid, maleic acid, malic acid, succinic acid, glycolic acid, glutaric acid, benzoic acid, malonic acid, salicylic acid, gluconic acid, polymeric acids, their salts, and mixtures thereof.
• a non-exclusive list of examples of mineral acid for use herein are hydrochloric, phosphoric, sulfuric and mixtures thereof.
• Polymeric acids are especially preferred acids for use herein from the standpoint that they cause less stinging to the skin than other acids, they can have less of a negative impact on lather than other acids and they can contribute to a draggy rinse feel which is preferred by some consumers.
• polymeric acid refers to an acid with repeating units of carboxylic acid groups joined together into one chain. Suitable polymeric acids can include homopolymers, copolymers and terpolymers, but must contain at least 30 mole% carboxylic acid groups.
• suitable polymeric acids useful herein include poly(acrylic) acid and its copolymers, both ionic and nonionic, (e.g., maleic-acrylic, sulfonic-acrylic, and styrene- acrylic copolymers), those cross-linked polyacrylic acids having a molecular weight of less than about 250,000, preferably less than about 100,000 poly ( ⁇ -hydroxy) acids, poly (methacrylic) acid, and naturally occurring polymeric acids such as carageenic acid, carboxy methyl cellulose, and alginic acid.
• Straight-chain poly(acrylic) acids are especially preferred for use herein.
• the liquid, rinse-off antimicrobial personal cleansing compositions herein comprise from about 0.1% to about 30%, preferably from about 1% to about 30% more preferably from about 3% to about 25%, most preferably from about 5% to about 25% of a deposition aid. It has been found that compositions which contain a deposition aid have improved antibacterial efficacy compared to compositions which do not contain a deposition aid.
• the deposition aid employed herein is one that increases the deposition of the antimicrobial active or the proton donating agent on the skin by at least about 20%, preferably by at least about 30%, more preferably at least about 50%.
• Suitable deposition aids for use herein include, for example, lipophilic skin moisturizing agents, cationic polymers, nonionic polymers, zeolites, clays and mixtures thereof.
• cationic polymers are believed to be effective deposition aids is that they can form coascervates with the anionic surfactant.
• Suitable cationic and nonionic polymers for use as a deposition aid herein include polyethylene glycols, polypropylene glycols, hydrolyzed silk proteins, hydrolyzed milk proteins, hydrolyzed keratin proteins, guar hydroxypropyltrimonium chloride, polyquats, silicone polymers and mixtures thereof.
• cationic or nonionic polymers are employed as the deposition aid, they are utilized at levels ranging from about 0.1% to about 1.0%, preferably from about 0.15% to about 0.8%, more preferably from about 0.2% to about 0.6% by weight of the composition.
• Lipophilic skin moisturizing agents are especially preferred as a deposition aid in the present invention.
• the lipid skin moisturizing agent provides a moisturizing benefit to the user of the personal cleansing product when the lipophilic skin moisturizing agent is deposited to the user's skin.
• lipophilic skin moisturizing agents are used as the deposition aid herein, they are employed at a level of about 1% to about 30%, preferably from about 3% to about 25%, most preferably from about 5% to about 25% by weight of the composition.
• the viscosity of the lipophilic skin moisturizing agent is represented by consistency (k) and shear index (n).
• the lipophilic skin moisturizing agents for use herein typically have a consistency (k) ranging from about 5 to about 5,000 poise, preferably from about 10 to about 3,000 poise, more preferably from about 50 to about 2,000 poise, as measured by the Consistency (k) Method hereinafter set forth in the Analytical Methods section.
• Suitable lipophilic skin moisturizing agents for use herein further have a shear index (n) ranging from about 0.01 to about 0.9, preferably from about 0.1 to about 0.5, more preferably from about 0.2 to about 0.5, as measured by the Shear Index Method hereinafter set forth in the Analytical methods section.
• lipophilic skin moisturizing agents having rheology properties other than those defined herein are either too easily emulsified and hence will not deposit, or are too "stiff to adhere or deposit on to skin and provide a moisturization benefit.
• the rheological properties of the lipophilic skin moisturizing agent are also important to user perception. Some lipophilic skin moisturizing agents, on deposition to the skin, are considered too sticky and are not preferred by the user.
• the lipophilic skin moisturizing agent can also desirably be defined in terms of its solubility parameter, as defined by Vaughan in Cosmetics and Toiletries. Vol. 103, p. 47-69, October 1988.
• a lipophilic skin moisturizing agent having a Vaughan solubility Parameter (VSP) from 5 to 10, preferably from 5.5 to 9 is suitable for use in the liquid personal cleansing compositions herein.
• VSP Vaughan solubility Parameter
• the lipophilic skin conditioning agent is selected from the group consisting of hydrocarbon oils and waxes, silicones, fatty acid derivatives, cholesterol, cholesterol derivatives, di- and tri-glycerides, vegetable oils, vegetable oil derivatives, liquid nondigestible oils such as those described in U.S. Patents 3,600,186 to Mattson; Issued August 17, 1971 and 4,005,195 and 4,005,196 to Jandacek et al; both issued January 25, 1977, all of which are herein incorporated by reference, or blends of liquid digestible or nondigestible oils with solid polyol polyesters such as those described in U.S.
• Fatty acids, fatty acid soaps and water soluble polyols are specifically excluded from our definition of a lipophilic skin moisturizing agent.
• Hydrocarbon oils and waxes Some examples are petrolatum, mineral oil micro- crystalline waxes, polyalkenes (e.g. hydrogenated and nonhydrogenated polybutene and polydecene), paraffins, cerasin, ozokerite, polyethylene and perhydrosqualene. Blends of petrolatum and hydrogenated and nonhydrogenated high molecular weight polybutenes wherein the ratio of petrolatum to polybutene ranges from about 90:10 to about 40:60 are also suitable for use as the lipid skin moisturizing agent in the compositions herein.
• Silicone Oils Some examples are dimethicone copolyol, dimethylpolysiloxane, diethylpolysiloxane, high molecular weight dimethicone, mixed C1-C30 alkyl polysiloxane, phenyl dimethicone, dimethiconol, and mixtures thereof. More preferred are non-volatile silicones selected from dimethicone, dimethiconol, mixed C1-C30 alkyl polysiloxane, and mixtures thereof. Nonlimiting examples of silicones useful herein are described in U.S. Patent No. 5,011,681, to Ciotti et al., issued April 30, 1991, which is incorporated by reference.
• Di- and tri-glycerides Some examples are castor oil, soy bean oil, derivatized soybean oils such as maleated soy bean oil, safflower oil, cotton seed oil, corn oil, walnut oil, peanut oil, olive oil, cod liver oil, almond oil, avocado oil, palm oil and sesame oil, vegetable oils and vegetable oil derivatives; coconut oil and derivatized coconut oil, cottonseed oil and derivatized cottonseed oil, jojoba oil, cocoa butter, and the like.
• soy bean oil soy bean oil, derivatized soybean oils such as maleated soy bean oil, safflower oil, cotton seed oil, corn oil, walnut oil, peanut oil, olive oil, cod liver oil, almond oil, avocado oil, palm oil and sesame oil, vegetable oils and vegetable oil derivatives
• coconut oil and derivatized coconut oil, cottonseed oil and derivatized cottonseed oil jojoba oil, cocoa butter, and the like.
• Acetoglyceride esters are used and an example is acetylated monoglycerides.
• Lanolin and its derivatives are preferred and some examples are lanolin, lanolin oil, lanolin wax, lanolin alcohols, lanolin fatty acids, isopropyl lanolate, acetylated lanolin, acetylated lanolin alcohols, lanolin alcohol linoleate, lanolin alcohol riconoleate.
• the lipophilic skin conditioning agent is comprised of lipids selected from the group consisting: petrolatum, blends of petrolatum and high molecular weight polybutene, mineral oil, liquid nondigestible oils (e.g. liquid cottonseed sucrose octaesters) or blends of liquid digestible or nondigestible oils with solid polyol polyesters (e.g.
• sucrose octaesters prepared from C22 fatty acids wherein the ratio of liquid digestible or nondigestible oil to solid polyol polyester ranges from about 96:4 to about 80:20, hydrogenated or nonhydrogenated polybutene, microcrystalline wax, polyalkene, paraffin, cerasin, ozokerite, polyethylene, perhydrosqualene, dimethicones, alkyl siloxane, polymethylsiloxane, methylphenylpolysiloxane and mixtures thereof.
• the ratio of petrolatum to the other selected lipids is preferably from about 10: 1 to about 1 :2, more preferably from about 5: 1 to about 1 :1.
• Liquid rinse-off antimicrobial cleansing compositions of the present invention comprise from about 35% to about 98.8%, preferably from about 45% to about 98%, more preferably from about 55% to about 97.5%, and most preferably from about 65% to about 95.99% water.
• Solid bar embodiments of the present invention preferably comprise from about 2% to about 25%, more preferably from about 3% to about 20% and most preferably from about 5% to about 15% water.
• Liquid rinse-off antimicrobial cleansing compositions of the present invention preferably have an apparent or neat viscosity of from about 500 cps to about 60,000 cps at 26.7°C, preferably 5,000 to 30,000 cps.
• viscosity as used herein means the viscosity as measured by a Brookfield RVTDCP with a spindle CP-41 at 1 RPM for 3 minutes, unless otherwise specified.
• the "neat” viscosity is the viscosity of the undiluted liquid cleanser.
• ingredients to enhance the mildness to the skin can be added.
• these ingredients include cationic and nonionic polymers, co-surfactants, moisturizers and mixtures thereof.
• Polymers useful herein include polyethylene glycols, polypropylene glycols, hydrolyzed silk proteins, hydrolyzed milk proteins, hydrolyzed keratin proteins, guar hydroxypropyltrimonium chloride, polyquats, silicone polymers and mixtures thereof.
• the mildness enhancing polymers comprise from about 0.1% to about 1%, preferably from about 0.2% to about 1.0%, and more preferably from about 0.2% to about 0.6%, by weight of the rinse-off antimicrobial cleansing composition, of the composition.
• Co-surfactants useful herein include nonionic surfactants such as the Genapol® 24 series of ethoxylated alcohols, POE(20) sorbitan monooleate (Tween® 80), polyethylene glycol cocoate and Pluronic® propylene oxide/ethylene oxide block polymers, and amphoteric surfactants such as alkyl betaines, alkyl sultaines, alkyl amphoacetates, alkyl amphodiacetates, alkyl amphopropionates, and alkyl amphodipropionates.
• the co-solvents comprise from about 20% to about 70%, preferably from about 20% to about 50%, by weight of the anionic surfactant, of the cleansing composition.
• Stabilizers such as the Genapol® 24 series of ethoxylated alcohols, POE(20) sorbitan monooleate (Tween® 80), polyethylene glycol cocoate and Pluronic® propylene oxide/ethylene oxide block polymers
• a stabilizer is also included at a level ranging from about 0.1% to about 10%, preferably from about 0.1% to about 8%, more preferably from about 0.1% to about 5% by weight of the composition.
• the stabilizer is used to form a crystalline stabilizing network in the liquid cleansing composition that prevents the lipophilic skin moisturizer agent droplets from coalescing and phase splitting in the product.
• the network exhibits time dependent recovery of viscosity after shearing (e.g., thixotropy).
• the stabilizers used herein are not surfactants.
• the stabilizers provide improved shelf and stress stability, but allow the liquid personal cleansing composition to separate upon lathering, and thereby provide for increased deposition of the lipophilic skin moisturizing agent onto the skin. This is particularly true when the cleansing emulsions of the present invention are used in conjunction with a polymeric diamond meshed sponge implement such as that described in Campagnoli; U.S. Patent 5,144,744; Issued September 8, 1992, herein incorporated by reference.
• the stabilizer employed in the personal cleansing compositions herein comprises a crystalline, hydroxyl-containing stabilizer.
• This stabilizer can be a hydroxyl-containing fatty acid, fatty ester or fatty soap water-insoluble waxlike substance or the like.
• the crystalline, hydroxy-containing stabilizer is selected from the group consisting of: (i) CH 2 - OR!
• Rl is -C-R4(CHOH R5(CHOH ⁇ R6;
• R is R ⁇ or H
• R4 is Co-20 A1
• R 5 is c 0-20 Alk !'
• R 6 is c o-2o A1
• R4 + R 5 + R 6 C 10 .22 and wherein 1 ⁇ x+y ⁇ 4;
• R 7 is -R 4 (CHOH) x R 5 (CHOH) y R 6
• M is Na + , K + or Mg ++ , or H;
• Some preferred hydroxyl-containing stabilizers include 12-hydroxystearic acid, 9,10- dihydroxystearic acid, tri-9, 10-dihydroxystearin and tri- 12-hydroxystearin (hydrogenated castor oil is mostly tri-12-hydroxystearin). Tri-12-hydroxystearin is most preferred for use in the emulsion compositions herein.
• hydroxyl-containing stabilizers When these crystalline, hydroxyl-containing stabilizers are utilized in the personal cleansing compositions herein, they are typically present at from about 0.1% to 10%, preferably from 0.1% to 8%, more preferably from 0.1% to about 5% of the liquid personal cleansing compositions.
• the stabilizer is insoluble in water under ambient to near ambient conditions.
• the stabilizer employed in the personal cleansing compositions herein can comprise a polymeric thickener.
• polymeric thickeners as the stabilizer in the personal cleansing compositions herein they are typically included in an amount ranging from about 0.01% to about 5%, preferably from about 0.3% to about 3%, by weight of the composition.
• the polymeric thickener is preferably an anionic, nonionic, cationic or hydrophobically modifier polymer selected from the group consisting of cationic polysaccharides of the cationic guar gum class with molecular weights of 1,000 to 3,000,000, anionic, cationic, and nonionic homopolymers derived from acrylic and/or methacrylic acid, anionic, cationic, and nonionic cellulose resins, cationic copolymers of dimethyldialkylammonium chloride, and acrylic acid, cationic homopolymers of dimethylalkylammonium chloride, cationic polyalklene and ethoxypolyalkylene imines, polyethylene glycol of molecular weight from 100,000 to 4,000,000, and mixtures thereof.
• the polymer is selected from the group consisting of sodium polyacrylate, hydroxy ethyl cellulose, cetyl hydroxy ethyl cellulose, and Polyquaternium 10.
• the stabilizer employed in the personal cleansing compositions herein can comprise C10-C22 ethylene glycol fatty acid esters.
• C10-C22 ethylene glycol fatty acid esters can also desirably be employed in combination with the polymeric thickeners hereinbefore described.
• the ester is preferably a diester, more preferably a C14-C18 diester, most preferably ethylene glycol distearate.
• C10-C22 ethylene glycol fatty acid esters are utilized as the stabilizer in the personal cleansing compositions herein, they are typically present at from about 3% to about 10%, preferably from about 5% to about 8%, more preferably from about 6% to about 8% of the personal cleansing compositions.
• Another class of stabilizer which can be employed in the personal cleansing compositions of the present invention comprises dispersed amorphous silica selected from the group consisting of fumed silica and precipitated silica and mixtures thereof.
• dispersed amorphous silica refers to small, finely divided non-crystalline silica having a mean agglomerate particle size of less than about 100 microns.
• Fumed silica which is also known as arced silica, is produced by the vapor phase hydrolysis of silicon tetrachloride in a hydrogen oxygen flame. It is believed that the combustion process creates silicone dioxide molecules which condense to form particles. The particles collide, attach and sinter together. The result of this process is a three dimensional branched chain aggregate. Once the aggregate cools below the fusion point of silica, which is about 1710°C, further collisions result in mechanical entanglement of the chains to form agglomerates, precipitated silicas and silica gels are generally made in aqueous solution.
• the fumed silica preferably has a mean agglomerate particle size ranging from about 0.1 microns to about 100 microns, preferably from about 1 micron to about 50 microns, and more preferably from about 10 microns to about 30 microns.
• the agglomerates are composed of aggregates which have a mean particle size ranging from about 0.01 microns to about 15 microns, preferably from about 0.05 microns to about 10 microns, more preferably from about 0.1 microns to about 5 microns and most preferably from about 0.2 microns to about 0.3 microns.
• the silica preferably has a surface area greater than 50 sq. m/gram, more preferably greater than about 130 sq. m./gram, most preferably greater than about 180 sq. m./gram.
• amorphous silicas When amorphous silicas are used as the stabilizer herein, they are typically included in the emulsion compositions at levels ranging from about 0.1% to about 10%, preferably from about 0.25% to about 8%, more preferably from about 0.5% to about 5%.
• a fourth class of stabilizer which can be employed in the personal cleansing compositions of the present invention comprises dispersed smectite clay selected from the group consisting of bentonite and hectorite and mixtures thereof.
• Bentonite is a colloidal aluminum clay sulfate. See Merck Index, Eleventh Edition, 1989, entry 1062, p. 164, which is incorporated by reference.
• Hectorite is a clay containing sodium, magnesium, lithium, silicon, oxygen, hydrogen and flourine. See Merck Index, eleventh Edition, 1989, entry 4538, p. 729, which is herein incorporated by reference.
• smectite clay When smectite clay is employed as the stabilizer in the personal cleansing compositions of the present invention, it is typically included in amounts ranging from about 0.1% to about 10%, preferably from about 0.25% to about 8%, more preferably from about 0.5% to about 5%.
• compositions of the present invention can comprise a wide range of optional ingredients.
• Nonlimiting examples of functional classes of ingredients are described at page 537 of this reference.
• Examples of these functional classes include: abrasives, anti-acne agents, anticaking agents, antioxidants, binders, biological additives, bulking agents, chelating agents, chemical additives, colorants, cosmetic astringents, cosmetic biocides, denaturants, drug astringents, emulsifiers, external analgesics, film formers, fragrance components, humectants, opacifying agents, plasticizers, preservatives, propellants, reducing agents, skin bleaching agents, skin-conditioning agents (emollient, humectants, miscellaneous, and occlusive), skin protectants, solvents, foam boosters, hydrotropes, solubilizing agents, suspending agents (nonsurfactant), sunscreen agents, ultraviolet light absorbers, and viscosity increasing agents (aqueous and nonaqueous).
• Examples of other functional classes of materials useful herein that are well known to one of ordinary skill in the art include solubilizing agents, sequestrants,
• the rinse-off antimicrobial cleansing compositions herein have the following characteristics.
• the rinse-off antimicrobial cleansing compositions of the present invention have a Gram Negative Residual Effectiveness Index of greater than about 0.3 (50% reduction), preferably greater than about 1.0 (90% reduction), more preferably greater than about 1.3 (95% reduction), and most preferably greater than about 2.0 (99% reduction).
• the Gram Negative Residual Effectiveness Index is measured by the fn-Vivo Residual Effectiveness on Escherichia coli Test described hereinafter in the Analytical Methods Section.
• the rinse-off antimicrobial cleansing compositions of the present invention comprise a Mildness Index of greater than about 0.3, preferably greater than about 0.4, and more preferably greater than about 0.6.
• the Mildness Index is measured by the Forearm Controlled Application Test (FCAT) described hereinafter in the Analytical Methods Section.
• the rinse-off antimicrobial personal cleansing compositions of the present invention are made via art recognized techniques for the various forms of personal cleansing products.
• the rinse-off antimicrobial personal cleansing compositions of the present invention are useful for personal cleansing, especially for cleansing of the hands.
• a suitable or effective amount of the cleansing composition is applied to the area to be cleansed.
• a suitable amount of the cleansing composition can be applied via intermediate application to a washcloth, sponge, pad, cotton ball, puff or other application device.
• the area to be cleansed can be premoistened with water.
• the compositions of the present invention are combined with water during the cleansing process and rinsed-off from the skin.
• an effective amount of product to be used will depend upon the needs and usage habits of the individual.
• Typical amounts of the present compositions useful for cleansing range from about 0.1 mg/cm ⁇ to about 10 mg/cm preferably from about 0.6 mg/cm ⁇ to about 5 mg/cm ⁇ skin area to be cleansed.
• volume I-IV Microbics Corporation.
• the stock solution of the test anionic surfactant sample is prepared and used as a stock solution from which all other dilutions are made.
• the standard "starting concentration", the highest concentration to be tested, is 500 ppm. (If a 500 ppm starting concentration fails to give a calculable result, e.g. an active surfactant kills all reagent at all dilutions, the starting concentration can be adjusted based on a known range of EC50 values of previously tested surfactants.)
• the stock solution is prepared at two times the starting concentration. a) Add O.lg (or adjusted amount if required) of anionic surfactant, accounting for activity of raw material, to beaker. b) Microtox Diluent (2% NaCl, Microbics Corp.) is added to total lOOg. c) Stir solution to make sure of adequate mixing.
• the concentration of test substance, in ppm, that decreases the bioluminescence of the Microtox Acute Toxicity Reagent by 50% from the starting value (EC50 Value) can be calculated using the Run Statistics on Data File option of the Microtox Software (recommended) or by conducting a linear regression of the data (% reduction vs. log of concentration). % Reductions are calculated using the following formulas:
• the Microtox Index is the EC50 value in ppm.
• Solubility protocol a) Prepare stock solution of TCS deprived formula with anionic surfactant level of 16% in 7-9 grain tap water.. b) Place 8 empty cuvettes into a test tube rack. c) Add 3 ml of the stock solution into a scintillation vial 1. d) Prepare five individual 3 ml solutions which are 1 :2, 1 :4, 1 :8, 1 :16, and 1 :32 dilutions of the stock solution in five scintillation vials (ending concentrations are 8%, 4% 2%, 1%, and 0.5%). e) To each vial add about 0.05g of the radio labeled TCS (from step 1-e above) and a magnetic stirring bar.
• the Solubility Slope, K is calculated by conducting a linear regression of maximum TCS solubility vs. surfactant concentration within the limits discussed below. a) For almost all surfactants the slope of the solubility curve between 1 and 2% surfactant is representative of K. b) For some surfactants the maximum TCS solubility curve remains linear outside the l-2%surfactant region. K must then be calculated from this entire linear region, such as from 0-4%, 1-4%, or 0.5-2% surfactant levels.
• Residual Antibacterial efficacy of liquid and bar soap antimicrobial products are quantified in the following method. Reductions are reported from a control, non- antibacterial placebo soap, without further treatment, used on one of the subjects forearms. By definition the antibacterial placebo will show no residual effectiveness in the test.
• Subjects are instructed not to use antibacterial products for 7 days prior to testing. Immediately before test, the subjects hands are examined for cuts/broken skin that would preclude them from participating.
• Wash Procedure a) Wash both forearms with control soap one time to remove any contaminants or transient bacteria. Rinse and dry forearms b) Test monitor wets gloved hands, places 1.0 ml of liquid test product (bar treatments are done according to above references) on forearm of subject, and lathers entire volar forearm with hand for 45 sec. c) Subjects forearms are then rinsed with 90-100°F tap water at a rate of 1 GPM for 15 seconds. d) Steps b-c are repeated two times (total 3 washes) for the test product. e) Arm is patted dry with paper towel and test sites are marked (-8.6 cm ⁇ circle with rubber stamp).
• E. coli inoculum ATCC 10536, grown from lyophilized stock in Soybean-casein broth at 37C for 18-24 hrs) is adjusted to approximately 10°* organisms/ml (0.45 transmittance vs. TSB blank on specrophotometer).
• Each test site is inoculated with 10 ⁇ l of E. coli. Inoculum is spread with inoculating loop into a ⁇ 3 cm ⁇ circle and covered with a Hilltop Chamber (Hilltop Research Inc.).
• This procedure is repeated for each test site on each forearm.
• Sampling Bacteria (Extraction Procedure) a) Prepare sampling solution of 0.04% KH2PO4, 1.01% Na2HP ⁇ 4, 0.1% Triton X- 100, 1.5% Polysorbate 80, 0.3% Lecithin in water, adjusted to pH 7.8 with 1 N HC1. b) Exactly 60 minutes after inoculation, the Hilltop Chamber is removed from the site from which a sample is to be taken. A 8.6 cm ⁇ sampling cup in placed over the site. c) 5 ml of sampling solution is added to the cup. d) Extract the bacteria by gently rubbing site with glass police man for 30 seconds. e) Remove sampling solution with pipette and place in a sterile labeled test tube. f) Repeat extraction with 5 ml of sampling fluid. This entire extraction procedure is repeated for each site 60 minutes after inoculation.
• Gram Negative Residual Efficacy Index log i j (CFU's/ml of placebo site) - logi Q (CFU's/ml of test product site)
• FOREARM CONTROLLED APPLICATION TEST FCAT
• Ertel K. D., et al.
• FCAT Forearm Controlled Application Test
• Test groups of 20-30 subjects, 18 to 55 years of age, who regularly wash with soap are used. Potential subjects who (1) have an initial dryness grade of 3.0 or higher on the forearms as assessed during the initial examination, (2) have skin cancer, eczema, or psoriasis on the forearms, (3) are receiving injectable insulin, (4) are pregnant or lactating, or (5) are receiving treatment for skin problems or contact allergy are excluded. Subjects are to avoid hot tubs, swimming, and sun lamps, and to refrain from applying any soaps, cleansing products, creams, or gels to their forearms for the duration of the study. Subjects are to keep water off their forearms for at least two hours before the grading process. The studies are executed using a blinded, random product order format. Clinical assistant should verify the correct treatment sequence and document such before washing each subject.
• Products are applied to the forearms a total of nine (9) times: two (2) times each day on the first four (4) days of the study and one (1) time on the final day. Visits to the test facility for washing must be spaced by a minimum of three (3) hours.
• Control Product All clinical assistants must wear disposable gloves during wash procedure, rinsing them between treatments, and changing between subjects.
• the control product is a rolled bar soap containing:
• the subject wets the entire surface of his/her volar forearm with 95-100°F tap water by holding the arm briefly under running tap water.
• a clinical assistant wets one-quarter sheet (approximately 8" x 6") of Masslinn® towel with tap water, then squeezes the towel gently to remove excess water.
• a clinical assistant applies the products to the arm, beginning with the product designated for the site nearest the elbow, using the appropriate procedure as follows:
• Liquid Product a. Dispense 0.10 cc of test product from a syringe into the center of the appropriate marked area. b. Wet two finders of gloved (latex) hand under the running tap (index and middle fingers). c. Move wetted fingers in a circular motion over the application site for 10 seconds to lather product. d. Lather remains on the application site for 90 seconds, then is rinsed off with running tap water for 15 seconds, taking care not to wash lather off the adjacent sites. After 10 seconds of the rinse has expired, the Clinical Assistant will gently rub the site being rinsed with her two gloved fingers for the remaining 5 seconds of the rinse..
• Bar Product a. Wet two finders of gloved (latex) hand under the running tap (index and middle fingers). b. Wet bar by holding bar briefly under running tap water. Test bars must be wet under a running tap at the start of each day. c. Rub wetted fingers in a circular motion, over the surface of the bar, for 15 seconds to form lather on bar and fingers. d. Rub the lathered fingers on the application site in a circular motion for 10 seconds to lather product on the skin. e. Lather remains on the application site for 90 seconds, then is rinsed off with running tap water for 15 seconds, taking care not to wash lather off the adjacent sites.
• Wipe Products a. Fold wipe in half, crosswise, and gently rub the wipe in a curricular motion within the appropriate area. b. Allow site to air dry for 90 seconds. Do not rinse site.
• Leave-on Product a. Dispense 0.10 cc of test product from a syringe into the center of the appropriate marked area. b. Move gloved fingers in a circular motion over the application site for 10 seconds. c. Allow site to air dry for 90 seconds. Do not rinse site.
• Steps 1-4 are repeated on the appropriate test areas so two applications of product are made to test areas.
• the clinical assistant gently pats the subject's arm dry with a disposable paper towel.
• the skin on each treatment area is evaluated by an expert grader at baseline and three hours after the final study wash.
• the treatment areas are evaluated under 2.75x magnification (model KFM-IA Luxo Illuminated Magnifying Lamp, Marshall Industries, Dayton, OH) with controlled lighting (General Electric Cool White, 22-watt, 8" Circuline fluorescent bulb).
• the skin is evaluated by an expert grader, for dryness and a rating is assigned based on the definitions set forth below.
• Rc 0 The average rating of control product area at baseline
• Rcf The average rating of control product area at test end
• Rt 0 The average rating of test product area at baseline
• Rtf The average rating if test product area at test end.
• the test is valid only if sufficient response is observed in the skin to the control product.
• the control response must be greater than 1.0 (i.e., Rcf - Rc 0 > 1.0) for the test to be valid.
• the Mildness Index of the test product is the difference in the skin responses to two products.
• the Cammed CSL 100 Controlled Stress Rheometer is used to determine Shear Index, n, and Consistency, k, of the lipophilic skin moisturizing agent used herein. The determination is performed at 35°C with the 4 cm 2° cone measuring system typically set with a 51 micron gap and is performed via the programmed application of a shear stress (typically from about 0.06 dynes/sq. cm to about 5,000 dynes/sq. cm) over time. If this stress results in a deformation of the sample, i.e. strain of the measuring geometry of at least 10-4 rad/sec, then this rate of strain is reported as a shear rate. These data are used to create a viscosity ⁇ Vs.
• the Wells-Brookfield Cone/Plate Model DV-II+ Viscometer is used to determine the viscosity of the liquid personal cleansing compositions herein. The determination is performed at 25°C with the 2.4 cm° cone (Spindle CP-41) measuring system with a gap of 0.013 mm between the two small pins on the respective cone and plate. The measurement is performed by injecting 0.5 ml of the sample to be analyzed between the cone and plate and rotating the cone at a set speed of 1 rpm. The resistance to the rotation of the cone produces a torque that is proportional to the shear stress of the liquid sample. The amount of torque is read and computed by the viscometer into absolute centipoise units (mPa's) based on geometric constants of the cone, the rate of rotation, and the stress related torque.
• mPa's absolute centipoise units
• Ingredients are identified by chemical or CTFA name.
• the liquid handsoaps shown all have a Gram Negative Residual Effectiveness Index of greater than about 0.3 and a Mildness Index of greater than 0.3.
• the shower gels shown all have a Gram Negative Residual Effectiveness Index of greater than about 0.3; and a Mildness Index of greater than 0.3.

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• 1998
  • 1998-05-29 EP EP98925004A patent/EP0996419A1/en not_active Withdrawn
  • 1998-05-29 WO PCT/US1998/010976 patent/WO1998055095A1/en not_active Application Discontinuation
  • 1998-05-29 CN CN98807394A patent/CN1129422C/zh not_active Expired - Fee Related
  • 1998-05-29 AU AU77046/98A patent/AU7704698A/en not_active Abandoned
  • 1998-05-29 JP JP50260699A patent/JP2002501542A/ja not_active Abandoned
  • 1998-06-04 PE PE1998000451A patent/PE77499A1/es not_active Application Discontinuation
  • 1998-06-04 AR ARP980102624A patent/AR012238A1/es not_active Application Discontinuation
  • 1998-06-04 CO CO98031811A patent/CO4940391A1/es unknown

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