ANTIMICROBIAL LIQUID CLEANSING COMPOSITIONS WHICH PROVIDE RESIDUAL BENEFITS VERSUS BACTERIAGRAM-NEGATIVASTECHNICAL FIELDThe present invention relates to mild and rinseable personal cleansing compositions that provide improved antimicrobial effectiveness. Specifically, the personal cleansing compositions of the invention provide residual effectiveness not previously seen against transient Gram-negative bacteria.
BACKGROUND OF THE INVENTIONHuman health is impacted by many microbial entities. Inoculation by means of viruses and bacteria causes a wide variety of diseases and conditions. Media attention to cases of food poisoning, strep infections and the like is increasing the public's awareness of microbial issues. It is well known that washing hard surfaces, foods (for example fruits or vegetables) and skin, especially hands, with antimicrobial or non-medicated soap, can remove many viruses and bacteria from washed surfaces. The removal of viruses and bacteria is due to the surfactant activity of the soap and the mechanical action of the washing process. Therefore, it is known and recommended that people wash frequently to reduce the spread of viruses and bacteria. The bacteria found on the skin can be divided into two groups: resident and transient bacteria. Resident bacteria are Gram-positive bacteria that are established as permanent microcolonies on the surface and outer layers of the skin and play an important and useful role in preventing the colonization of other more harmful bacteria and fungi. Transient bacteria are bacteria that are not part of the normal resident flora of the skin, but can be deposited when airborne material lands on the skin or when contaminated material comes 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 bacteria by an additional protective cell membrane that generally results in Gram-negative bacteria being less susceptible to topical antibacterial actives.
Antimicrobial products for personal cleansing have been marketed in a variety of ways for some time. The forms include deodorant soaps, hard surface cleaners and surgical disinfectants. These traditional rinsing antimicrobial products have been formulated to provide bacteria removal during washing. Antimicrobial soaps have also been shown to provide residual effectiveness against Gram-positive bacteria, but limited residual effectiveness against Gram-negative bacteria. By residual effectiveness, it is tried to say that the growth of bacteria on a surface is controlled during a certain period after the washing / rinsing process. Personal antimicrobial liquid cleaners are described in the US patents. Nos. 4,847,072, Bissett et al., Issued July 1, 1989; 4,939,284, Degenhardt, issued July 3, 1990 and 4,820,698, Degenhardt, issued April 1, 1989, all of which are incorporated herein by reference. The previously commercialized formulations of the shampoo for dandruff Head & Shoulders®, marketed until 1994, comprise anionic surfactants, an antibacterial active and citric acid as a pH adjuster. Head & Shoulders® controls the fungus Pityrosorum ovale, which causes dandruff. The PCT application WO 92/18100, Keegan et al.; published October 29, 1992 ("Keegan") and the PCT application WO 95/32705, Fujiwara et al; published on December 7, 1995 ("Fujiwara") show liquid skin cleansers comprising mild surfactants, antibacterial agents, and acid compounds to regulate pH, which provide improved hostility to germs. However, the use of the low levels of the acidic compounds there results in compositions that do not provide the disassociated acid required to provide the residual effectiveness against Gram negative bacteria. This situation is compounded in Keegan and Fujiwara by the preference of mild surfactants, including nonionic surfactants. Some of these antimicrobial products, especially hard surface cleaners and surgical disinfectants, use high levels of alcohol and / or surfactants that have been shown to dry and irritate skin tissues. Ideal personal cleansers should gently cleanse the skin, causing little or no irritation, and not leaving the skin or hair extremely dry after frequent use, and preferably should provide a moisturizing benefit to the skin. The patent of E.U.A. No. 3, 141, 821, issued to Compeau on July 21, 1964 and Irgasan DP 300 (Triclosan®) technical literature from Ciba-Giegy, Inc., "Basic Formulation for Hand Disinfection 89/42/01" describe antibacterial compositions for skin cleansing that could provide residual effectiveness against Gram-negative bacteria using certain anionic surfactants, antimicrobial actives and acids. However, the selection, there, of highly active surfactants results in personal cleansing compositions that dry and are aggressive to the skin.
Given the severe health impacts of Gram-negative bacteria such as Salmonella, Escherichia coli and Shigella, it would be highly desirable to formulate antimicrobial personal cleansing compositions that would provide residual effectiveness against these Gram-negative bacteria and be gentle to the skin. Existing consumer products have been unable to achieve both Gram negative and softness residual effectiveness. Applicants have discovered that the rinseable personal cleansing antimicrobial compositions that provide such softness and said residual effectiveness against Gram negative bacteria can be formulated using known antimicrobial actives in combination with specific organic and / or inorganic acids as proton donor agents, and surfactants. specific anionics, all of which are deposited on the skin. The deposited proton donor agent and the anionic surfactant enhance the selected asset, to provide a new level of hostility to bacteria that make contact with the skin.
BRIEF DESCRIPTION OF THE INVENTIONThe present invention relates to a rinseable antimicrobial composition for personal cleansing comprising about 0.001% to about 5% of an antimicrobial active; about 1% to about 80% of an anionic surfactant; about 0.1% to about 12% of a proton donor agent; about 0.1% to about 30% of a deposition aid and 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 rinsing antimicrobial compositions for personal cleansing also have a Residual Effectiveness Index Against Gram Negative Organisms of more than about 0.3; and a Softness index of more than 0.3. The present invention also relates to cleaning methods and to reducing the distribution of transient Gram-negative bacteria using the rinse-off antimicrobial compositions for personal cleansing described herein.
DETAILED DESCRIPTION OF THE INVENTIONThe rinsing antimicrobial compositions for personal cleansing of the present invention are very effective in cleaning surfaces, especially the skin, providing a residual antimicrobial effectiveness against transient Gram-negative bacteria and are gentle on the skin. The term "rinsings" is used herein to mean that the compositions of the present invention are used in a context in which the composition is rinsed or finally washed from the treated surface (e.g., skin or hard surfaces) either after or during the application of the product. The term "antimicrobial composition for personal cleansing", as used herein, refers to a composition suitable for application to a surface for the purpose of removing dirt, oil and the like which additionally controls the growth and colonization of bacteria. Gram negative transients. Preferred embodiments of the present invention are personal cleansing compositions suitable for use on human skin. The compositions of the present invention may also be useful for the treatment of acne. As used herein, "acne treatment" refers to the prevention, delay and / or arrest of the acne formation process in mammalian skin. The compositions of the invention may also be potentially useful in providing essentially immediate (ie, acute) visual improvement in the appearance of the skin after application of the composition thereto. More particularly, the compositions of the present invention are useful for regulating the condition of the skin, including the regulation of visible and / or tactile discontinuities in the skin, including but not limited to visible and / or tactile discontinuities in texture and / or skin color, more specifically discontinuities associated with skin aging. Such discontinuities can 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, aggressive surfactants, abrasives and the like. Intrinsic factors include chronological aging and other biochemical changes from within the skin. The regulation of skin conditions includes regular prophylactic and / or therapeutically skin condition. As used herein, prophylactically regulating the condition of the skin includes delaying, minimizing and / or avoiding visible and / or tactile discontinuities in the skin. As used herein, therapeutically regulating the condition of the skin includes improving, for example, decreasing, minimizing and / or eliminating such discontinuities. The regulation of skin condition includes providing a smoother and more uniform skin appearance and / or sensation. As used herein, regulating the condition of the skin includes regular signs of aging. "Regulating signs of skin aging" includes prophylactically and / or therapeutically regulating one or more of such signals (similarly, regulating a given signal of skin aging, eg, lines, wrinkles or pores, includes prophylactically regular and / or therapeutically regulate said signal). The "signs of aging of the skin" include, but are not limited to, all externally visible and tactilely perceptible manifestations, as well as any other macro or micro effect caused by the aging of the skin. These signals can be induced or caused by intrinsic factors or extrinsic factors, for example, chronological aging and / or environmental damage. These signals may result from processes that include, but are not limited to, the development of texture discontinuities such as wrinkles, including both fine surface wrinkles and deep, deep wrinkles, skin lines, folds, rashes, large pores (e.g. , associated with attached structures such as ducts of sweat glands, sebaceous glands or hair follicles), scars and / or other forms of disuniformity or roughness of the skin, loss of skin elasticity (loss and / or inactivation of functional elastin in the skin), softening (including swelling in the eye area and dark circles), loss of skin firmness, loss of skin stiffness, loss of skin recovery from deformation, discoloration (including circles underneath) of the eye), rashes, pallor, hyperpigmented skin regions such as age spots and freckles, keratosis, abnormal differentiation, hyperkeratinization, astosis, collagen degradation and other histological changes in the stratum corneum, dermis, epidermis, the vascular system of the skin (eg, telangiectasia or spider vessels), and underlying tissues, especially those close to the skin. All percentages and ratios used herein, unless otherwise indicated, are by weight, and all measurements are made at 25 ° C, unless otherwise designated. The invention herein may comprise, consist of or consist essentially of, the essential and optional ingredients and components described therein.
I. Ingredients The rinsing antimicrobial compositions for personal cleansing of the present invention comprise an antimicrobial active, an anionic surfactant, a proton donating agent and a deposition aid. These components are selected so as to meet the efficiency and softness needs defined hereinbelow for the compositions herein. The selection of each component necessarily depends on the selection of each of the other components. For example, if a weak acid is selected as the proton donor agent, then to be able to obtain an effective composition, a more biologically active (but less mild) surfactant should be employed and / or a high level of acid should be used in The prescribed scale and / or a particularly effective asset should be used and / or a higher level of deposition aid should be used on the prescribed scale. Similarly, if a mild but ineffective surfactant is employed, then a stronger acid may be necessary and / or a high level of deposition aid may be necessary to obtain an effective composition. If an aggressive surfactant is used, then a mildness agent or a lipophilic skin moisturizing ingredient would have to be used as the deposition aid. The guidelines for the selection of the individual components are provided herein.
A. Antimicrobial Active The rinse-off antimicrobial compositions for personal cleansing of the present invention comprise from 0.001% to about 5%, preferably from about 0.01% to about 2%, most preferably from about 0.05% to about 1.5% and more preferably about 0.1% to about 1.0% of an antimicrobial active. The exact amount of antibacterial active that will be used in the compositions will depend on the particular asset used, since the assets vary in potency. Non-cationic actives are required in order to avoid interaction with the anionic surfactants of the invention. Examples of non-cationic antimicrobial agents that are useful in the present invention are given below. Pyrithiones, especially the zinc complex (ZPT) Octopirox1 * 1 >Dimethyldimethylol Hidantoin (Glidant * ^ ®) \Methylchloroisothiazolinone / Methylisothiazolinone (Kathon CG®) Sodium Sulfite Sodium Bisulfite Imidazolidinylurea (Germall 1 15®) Diazolidinylurea (Germall II) Benzyl alcohol 2-Bromo-2-nitropropane-1,3-diol (Bronopol®) Formalin (formaldehyde) Butylcarbamate of iodopropenyl (Polifase P100®) Chloroacetamide Methanamine Methyldibromonitrile-Glutaronitrile (1,2-Dibromo-2,4-dicyanobutane or Tektamer®) 10 Glutaraldehyde 5-bromo-5-nitro-1,3-dioxane (Bronidox®) Phenethyl alcohol or Sodium phenylphenol / o-phenylphenol Sodium hydroxymethylglycanat (Suttocide A®) 15 Bicyclic polymethoxyoxazolydin (Nuosept C®) Dimetoxan Timeric Dichlorobenzyl alcohol Captan 20 Chlorphenenesin Dichlorophene Chlorbutanol Glyceryl laurethylene diphenyl ethers 2,4,4'-trichloroether '-hydroxy-diphenyl (Triclosan® or TCS) 2, 2'-dihydroxy-5,5'-dibromo-diphenyl ether Phenol compounds Phenol 2-Methylphenol 3-Methylphenol 4-Methylphenol 4-Ethyl enol 10 2,4-Dimethylphenol 2,5-Dimethylphenol 3,4-Dimethylphenol 2,6-Dimethylphenol 4-n-Propylphenol 15 4-n-Butylphenol 4-n-Amylphenol 4-ter-Amylphenol 4-n-Hexylphenol 4- n-Heptyphenol 20 Aromatic mono- and poly-alkenyl halophenols p-chlorophenol Methyl p-chlorophenol Ethyl p-chlorophenol n-propyl p-chlorophenol n-butyl p-chlorophenol n-amyl p-chlorophenol sec-amyl p-chlorophenol n-hexyl p-chlorophenol Cyclohexyl p-chlorophenol n-heptyl p-chlorophenol n-octyl p-chlorophenol o-chlorophenol 10 Methyl o-chlorophenol Ethyl o-chlorophenol n-propyl o-chlorophenol n-butyl o-chlorophenol n-amyl o-chlorophenol ter-amyl o-chlorophenol n-hexyl o-chlorophenol n-heptyl o-chlorophenol o-benzyl p-chlorophenolo-benzyl-m-methyl p-chlorophenol o-benzyl-m, m-dimethyl p-chlorophenol 20 o-phenylethyl p-chlorophenol or phenylethyl-m-methyl p-chlorophenol 3-methyl p-chlorophenol 3,5-dimethyl p-chlorophenol 6-ethyl-3-methyl p-chlorophenol 6- n-propyl-3-methyl p-chlorophenol 6-p-propyl-3-methyl p-chlorophenol 2-ethyl-3,5-dimethyl p-chlorophenol 6-sec-butyl-3-methyl p-chlorophenol 2-¡ so-propyl-3,5-dimethyl p-chlorophenol 6-diethylmethyl-3-methyl p-chlorophenol 6-iso-propyl-2-ethyl-3-methyl p-chlorophenol 2-sec-amyl-3,5-dimethyl p -chlorophenol10 2-diethylmethyl-3,5-dimethyl p-chlorophenol 6-sec-octyl-3-methyl p-chlorophenol p-chloro-m-cresol p-bromophenol Methyl p-bromophenol 15 Ethyl p-bromophenol n-propyl p-bromophenol n-butyl p-bromophenol n-amyl p-bromophenol sec-amyl-p-bromophenol 20 n-hexyl p-bromophenol Cyclohexyl p-bromophenol o-bromophenol ter-amyl o-bromophenol n-hexyl o-bromophenol n-propyl-m , m-dimethyl o-bromophenol 2-phenylphenol 4-chloro-2-methylphenol 4-chloro-3-methylphenol 4-chloro-3,5-dimethylphenol 2,4-dichloro-3,5-dimethylphenol 3,4,5, 6-terabromo-2-methylphenol 5-methyl-2-pentylphenol 10 4-isopropy-3-methylphenol Para-chloro-meta-xylene (PCMX) Chlorotimol Phenoxyethanol Phenoxyisopropanol 15 5-chloro-2-hydroxydiphenylmethane Resorcinol and its derivatives Resorcinol Methylresorcinol Ethylesorcinol 20 n-propylresorcinol n-butylresorcinol n-amilresorcinol n-hexylresorcinol n-heptylresorcinol n-octylresorcinol n-nonilresorcinol phenylresorcinol Bencilresorcinol Phenylethylresorcinol Phenylpropyresorcinol p-chlorobenzyl esorcinol 5-chloro-2,4-dihydroxydiphenylmethane 10 4'-chloro-2,4-dihydroxydiphenylmethane 5-bromo-2,4-dihydroxydiphenylmethane 4'-bromo-2,4-dihydroxydiphenylmethane Bisphenol-2,2'-methylene-bis (4-chlorophenol) compounds 15 2,2'-methylene bis (3,4,6-trichlorophenol) 2,2'-methylene bis (4-chloro-6-bromophenol) Bis (2-hydroxy-3,5-dichlorophenyl) sulfide Bisulfide (2-hydroxy-5-chlorobenzyl) Benzoic esters (Parabens) 20 Methylparaben Propylparaben Butylparaben Ethylparaben Isopropylparaben Isobutylparaben Benzylparaben Methylparaben sodium Propylparaben sodium CarbanilidesHalogenates 3,4,4'-trichlorocarbanilides (Triclocarban, ® ^ or TCC) 3-trifluoromethyl-4 , 4'-dichlorocarbanilide 3,3 ', 4-trichlorocarbanilide Another class of antibacterial agents that are useful in the present invention are so-called "natural" antibacterial actives, referred to as natural essential oils. These assets derive their names from their natural occurrence in plants. The natural antibacterial assets of typical essential oils include anise, lemon, orange, rosmarine, rosemary, thymus, lavender, clavero, hops, tea tree, citronella, wheat, barley, lemon, cedar leaf, cedar wood, cinnamon , grass pulguera, geranium, sandalwood, violet, blueberry, eucalyptus, verbena, pepper, benzoin gum, basil, fennel, spruce, balsam, menthol, ocmea origanum, Hydastis carradensis, Berberidaceae daceae, Ratanhiae and Turmeric tonga. Also included in this class of natural essential oils are the key chemical components of vegetable oils that have been discovered to provide an antimicrobial benefit.
These chemicals include, but are not limited to, anethole, catechol, camphene, thymol, eugenol, eucalyptol, ferulic acid, famesola, inoquitiol, tropolone, limene, menthol, methyl salicylate, thymol, terpineol, verbenone, berberine, ratane extract. , cariophelene oxide, citronellic acid, curcumin, nerolidol and geraniol. The 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 aluminum, zirconium, zinc, silver, gold, copper, lanthanum, tin, mercury, bismuth, selenium, strontium, yttrium, yttrium, praseodymium, neodymium, prometheus, samarium, europium, gadolinium, terbium, dysprosium salts , holmium, erbium, thulium, ytterbium, lutetium and mixtures thereof. Preferred antimicrobial agents for use herein are the broad spectrum active 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 in the present invention is Triclosan®.
B. Anionic Surfactant The liquid embodiments of the rinse-off antimicrobial compositions for personal cleansing of the present invention comprise an anionic surfactant at scales of 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 composition for personal cleansing. The solid stick embodiments of the present invention preferably comprise from about 10% to about 70% and most preferably from about 20% to about 60% of the anionic surfactant. Without being limited by theory, it is believed that the anionic surfactant breaks the lipid in the cell membrane of bacteria. The particular acid used herein reduces the negative charges on the cell wall of the bacteria 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. Non-limiting examples of anionic foam forming surfactants useful in the compositions of the present invention are described in McCutcheon's, Deterqents and Emulsifiers, North American edition (1990), published by The Manufacturing Confectioner Publishing Co.; McCutcheon's, Functional Materials, North American edition (1992); and in U.S. Patent No. 3,929,678 to Laughlin et al., issued December 30, 1975, all of which are incorporated by reference. A wide variety of anionic surfactants are potentially useful herein. Non-limiting examples of foaming anionic surfactants include those selected from the group consisting of alkyl sulfates and alkyl ether sulphates, sulphated monoglycerides, sulfonated olefins, alkylarylsulfonates, primary and secondary alkane sulphonates, alkylsulfosuccinates, acyltaurates and acylisates, hereglycerylether sulfonates, sulfonated methyl esters, fatty acids sulphonates, alkyl phosphates, acylglutamates, acyl sarcosinates, alkylsulfoacetates, acylated peptides, alkylcarboxylates, acylactylates, fluoroanionic surfactants and mixtures thereof. Mixtures of anionic surfactants can be used effectively in the present invention. Anionic surfactants for use in personal cleansing compositions include alkyl sulfates and alkyl ether sulphates. These materials have the respective formulas R1O-SO3M and R1 (CH2H40) x-0-S03M, wherein R1 is a saturated or unsaturated, branched or unbranched alkyl group of 8 to 24 carbon atoms, x is from 1 to 10, and M is a water-soluble cation such as ammonium, sodium, potassium, magnesium, triethanoiamine, diethanolamine and monoethanolamine. The alkyl sulfates are preferably made by sulfation of monohydric alcohols (having from 8 to 24 carbon atoms) using sulfur trioxide or other known sulfation technique. The alkyl ether sulphates are typically made as condensation products of ethylene oxide and monohydric alcohols (having from 8 to 24 carbon atoms) and then sulfated. These alcohols can be derived from fats, for example, coconut or wood oils, or they can be synthetic. Specific examples of alkyl sulfates which can be used in personal cleansing compositions are sodium, ammonium, potassium, magnesium salts, or TEA salts of lauryl sulfate or myristyl. Examples of alkyl ether sulfates that can be used include laureth-3 ammonium sulfate, sodium, magnesium or TEA. Another suitable class of anionic surfactants are the sulfated monoglycerides of the form R 1 CO-O-CH 2 -C (OH) H-CH 2 -O-SO 3 M, wherein R 1 is a saturated or unsaturated, branched or unbranched alkyl group of 8 to 24 carbon atoms, and M is a water-soluble cation such as ammonium, sodium, potassium, magnesium, triethanolamine, diethanolamine and monoethanolamine. These are typically made by the reaction of glycerin with fatty acids (having from 8 to 24 carbon atoms) to form a monoglyceride and the subsequent sulfation of this monoglyceride with sulfur trioxide. An example of a sulfated monoglyceride is sodium cocomonoglyceride sulfate. Other suitable anionic surfactants include olefin sulfonates of the formula R1SO3M, wherein R1 is a mono-olefin having from 12 to 24 carbon atoms, and M is a water-soluble cation such as ammonium, sodium, potassium, magnesium, triethanolamine , diethanolamine and monoethanolamine. These compounds can be produced by the sulfonation of alpha olefins by means of unconcomplexed sulfur trioxide, followed by the neutralization of the acid reaction mixture under conditions such that any sulfone that has been formed in the reaction is hydrolyzed to give the corresponding hydroxyalkanesulfonate. An example of a sulfonated olefin is alphaolefin sulfonate of C? -C? 6.
Other suitable anionic surfactants are the linear sulfoalkylbenzenesulfonates of the formula R1-C6H -S03M, wherein R1 is a saturated or unsaturated, branched or unbranched alkyl group of 8 to 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 alkylbenzene with sulfur trioxide. An example of this anionic surfactant is sodium dodecylbenzenesulfonate. Still other suitable anionic surfactants for this cleaning composition include the primary or secondary alkan sulfonates of the formula R1S03M, wherein R1 is a saturated or unsaturated, branched or unbranched alkyl chain of 8 to 24 carbon atoms, and M is a water-soluble cation such as ammonium, sodium, potassium, magnesium, triethanolamine, diethanolamine and monoethanolamine. These are commonly formed by the sulfonation of paraffins using sulfur dioxide in the presence of chlorine and ultraviolet light or another known sulfonating method. Sulfonation can occur in the secondary or primary positions of the alkyl chain. An example of an alkan sulfonate useful herein is the alkali metal or ammonium paraffinsulfonate of C13-C17. Other suitable surface-active agents are alkyl sulfosuccinates, which include disodium N-octadecylsulfosucinamate; diammonium lauryl sulfosuccinate; N- (1,2-dicarboxyethyl) -N-octadecylsulfosucinate tetrasodium; diamyl ester of sodium sulfosucinic acid; dihexyl ester of sodium sulfosuccinic acid; and dioctyl esters of sodium sulfosuccinic acid. Also useful are taurates based on taurine, which is also known as 2-aminoethane-sulphonic acid. Examples of taurates include N-alkyltaurines such as that prepared by reacting dodecylamine with sodium isethionate according to the teaching of the U.S. patent. 2,658,072, which is incorporated herein by reference in its entirety. Other examples based on taurine include the acyl taurines formed by the reaction of N-methyltaurine with fatty acids (having from 8 to 24 carbon atoms). Another class of anionic surfactants suitable for use in the cleaning composition are the acyl isethionates. Acyl isethionates typically have the formula R 1 CO-0-CH 2 CH 2 S 3 M, wherein R 1 is a saturated or unsaturated, branched or unbranched alkyl group having from 10 to 30 carbon atoms, and M is a cation. These are typically formed by the reaction of fatty acids (having from 8 to 30 carbon atoms) with an alkali metal isethionate. Non-limiting examples of these acyl isethionates include cocoyl ammonium isethionate, sodium cocoyl setionate, sodium laureth isethionate, and mixtures thereof. Still other suitable anionic surfactants are the alkylglyceryl ether sulphonates of the form R1-CH (S04) -COOH, wherein R1 is a saturated or unsaturated, branched or unbranched alkyl group of 8 to 24 carbon atoms, and M is a water-soluble cation such as ammonium, sodium, potassium, magnesium, triethanolamine, diethanolamine and monoethanolamine. These can be formed by the reaction of epichlorohydrin and sodium disulphide with fatty alcohols (having from 8 to 24 carbon atoms) or other known methods. An example is sodium co-glyceryl sulphonate ether. Other suitable anionic surfactants include the sulfonated fatty acids of the formula R1-CH (S04) -COOH and the sulfonated methyl esters of the formula R1-CH (S0) -CO-0-CH3, wherein R1 is an alkyl group saturated or unsaturated, branched or unbranched, from 8 to 24 carbon atoms. These may be formed by the sulfonation of fatty acids or methylalkyl esters (having from 8 to 24 carbon atoms) with sulfur trioxide or by another known sulfonating technique. Examples include aliphatic acid coconut fatty acid and laurimethyl ester. Other anionic materials include phosphates such as monoalkyl salts, dialkyl, and trialkyl phosphate formed by the reaction of phosphorus pentaxide with branched or unbranched monohydric alcohols having from 8 to 24 carbon atoms. These could also be formed by other known phosphating methods. An example of this class of surfactants is sodium mono or dilauryl phosphate. Other anionic materials include acyl glutamates corresponding to the formula R1CO-N (COOH) -CH2CH2-C02M, wherein R1 is a saturated or unsaturated, branched or unbranched alkyl or alkenyl group, of 8 to 24 carbon atoms, M is a cation soluble in water. Non-limiting examples of which include sodium lauroylglutamate and sodium cocoylglutamate. Other anionic materials include alkanoyl sarcosinates corresponding to the formula R1CON (CH3) -CH2CH2-C2M wherein R1 is a saturated or unsaturated, branched or unbranched alkyl or alkenyl group, of 10 to 20 carbon atoms, and M is a cation soluble in water. Non-limiting examples of which include sodium lauroyl sarcosinate, sodium cocoyl sarcosinate and lauroyl sarcosinate ammonium. Other anionic materials include the alkyl ether carboxylates corresponding to the formula R1- (OCH2CH2) x-OCH2-C2M, wherein R1 is a saturated or unsaturated, branched or unbranched alkyl or alkenyl group of 8 to 24 carbon atoms, x is 1 to 10, and M is a water-soluble cation. Non-limiting examples of which include sodium lauretcarboxylate. Other anionic materials include acyl lactylates corresponding to the formula R1CO- [0-CH (CH3) -CO] x-C02M, wherein R1 is a saturated or unsaturated, branched or unbranched alkyl or alkenyl group of 8 to 24 atoms of carbon, x is 3, and M is a water-soluble cation. Non-limiting examples of which include sodium lauroylcarboxylate, sodium cocoylcarboxylate, and ammonium lauroylcaboxylate. The fluoroanionic surfactants can also be used.
Any countercation, M, can be used on the anionic surfactant. Preferably the counter cation is selected from the group consisting of sodium, potassium, ammonium, monoethanolamine, diethanolamine, and triethanolamine. More preferably the countercation is ammonium. When selecting the surfactant or surfactants to be employed in the antibacterial cleansing compositions herein, three factors must be taken into account: 1) the activity of the surfactant molecule in the bacterial cell membrane; 2) the solubility characteristics of the active selected in the surfactant and 3) the softness of the surfactant, since it affects the Softness index (described below) for the antimicrobial composition.
Biological Activity / Smoothness of the Surfactant In general, the higher the biological activity of the surfactant, the more residual effectiveness is provided by the composition comprising the surfactant. However, typically the biological activity of a surfactant and the smoothness of a surfactant are inversely proportional; the higher the biological activity of the surfactant, the more aggressive the surfactant will be, and the lower the biological activity of the softer surfactant will be. Whether a biologically active but aggressive surfactant or a mild but biologically inactive surfactant is desired will, of course, depend on the selection (or influence) of the other components. The biological activity / smoothness of a pure surfactant can be measured directly by means of a Microtox response test described hereinafter in the section on Analytical Methods, and can be reported as a Microtox Response Index. By "pure surfactant" is meant a chemical composition consisting essentially of a single surfactant entity, wherein the entity has essentially a chain length, main and anti-sai ion groups. From a viewpoint of high biological activity, the preferred anionic surfactants of the antimicrobial cleansing compositions of the present invention have a Microtox Response Index of less than about 150, most preferably less than about 100 and more preferably less. from about 50. From a mildness standpoint, the preferred anionic surfactants of the antimicrobial cleansing compositions of the present invention have a Microtox Response Index of greater than about 25, most preferably more than about 50 and more preferably more than about 100. Surfactants with a Microtox Response Index ranging from about 25 to about 150 are typically moderately and moderately mildly biologically active.
For surfactant compositions which are mixtures of surfactants rather than pure surfactants (this includes "commercial grade" surfactants which typically comprise mixtures of entities with different chain lengths and which have potentially higher levels of impurities), the Microtox Response Index for any single surfactant component it is not a reliable measurement of biological activity or smoothness. In the case of mixtures, 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 unknown, then the upper group and chain lengths of the surfactant mixture is a better indicator of biological activity / smoothness. The anionic surfactants or mixtures of surfactants with a chain length mainly in the range of about 8 to about 24 carbon atoms, preferably mainly about 10 to about 18 carbon atoms and most preferably mainly about 12 to about 16 atoms carbon are preferred from the point of view of high biological activity. As used herein "mainly" means at least about 50% from a softness point of view, it is preferable to minimize C12.
From the point of view of biological activity, it is preferred that the upper group of the anionic surfactant measure less than about 15 Angstroms, preferably less than about 10 Angstroms and more preferably less than about 7 Angstroms. The "upper group" is defined as the hydrophilic (non-hydrocarbon) portion of the anionic surfactant, measured from the first polar atom to the end of the molecule. The size of the upper group is calculated from the Van der Waals radius of the atoms and the configuration of the surfactant molecule. Higher groups with sizes of less than about 7 Angstroms include sulfates, sulfonates and phosphates. From the point of view of smoothness, it is preferred that the upper group measure more than about 7 Angstroms, and preferably more than about 10 Angstroms. Higher groups with sizes of more than about 10 Angstroms include ethoxylated sulfates, glyceryl ether sulfonates and isethionates. It is believed that by increasing the size of the upper group, a more stearic impediment in the cell wall prevents the disruption by the surfactant and, in this way, the biological activity is decreased and the softness is increased. The smoothness of a surfactant or mixture of surfactants can also be determined by a number of other conventional and known methods for measuring the smoothness of the surfactant. For example, the Barrier Destruction Test described in T.J. Franz, J. Invest. Dermatol., 1975, 64, pp. 190-195 and in the patent of E.U.A. Do not.4,673,525 to Small and others; issued June 16, 1987, both incorporated herein by reference, is a way to measure the smoothness of surfactants. In general, the milder the surfactant, the lesser the skin barrier is destroyed in the barrier destruction test. Barrier destruction of the skin is measured by the relative amount of radioactively labeled water that passes from the wet solution through the epidermis of the skin into the physiological pH regulator contained in the diffusion chamber. Surfactants having a Relative Skin Penetration Value as close to zero as possible to about 75 are considered mild for the purposes of the present. Surfactants having a Relative Skin Penetration Value of more than about 75 are considered aggressive for the purposes of the present.
Slope of solubility of antimicrobial active in anionic surfactant The preferred anionic surfactants are also selected, in part, based on the ability of the surfactant to deposit the antimicrobial active on the skin. The surfactants for use herein must have sufficient solubility to carry the active and the solubility must not be so high that the active substance remains in solution during use, resulting in no active substance being deposited on the skin. It has been found that this balance is best measured by the slope of the solubility curve of the antimicrobial active against the concentration of the surfactant in water. This slope, hereinafter referred to as the solubility slope, K, is determined by the test method described hereinafter 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, most preferably less than about 0.25, and more preferably less than about 0.10. The rinse-off antimicrobial compositions for personal cleansing of the present invention preferably deposit about 0.01 μg / cm2 to about 100 μg / cm2, most preferably about 0.1 μg / cm2 to about 50 μg / cm2 and more preferably about 1 μg / cm2 to approximately 20 μg / cm2 of antimicrobial active on the skin. For the personal cleansing compositions herein to be effective, both the biological activity of the surfactant and the solubility of the particular active used in the surfactant must be taken into account. For example, ammonium lauryl sulfate, ALS, is very biologically active (Microtox index = 1.0) but has a relatively high solubility slope (K = 0.3). the compositions comprising ALS are capable of providing very effective residual antibacterial effectiveness thanks to their activity, even with lower levels of antibacterial active and proton donor agent. However, in order to deposit the active on the skin (which is required to satisfy the efficiency requirements described herein), higher levels of active will be necessary as a result of the high solubility slope. Moreover, compositions containing ALS may require the addition of surfactant coagents or polymers, described herein in the section on Optional Ingredients, to achieve highly preferred levels of softness for the present invention. A selection of ammonium laureth sulfate (microtox = 120 and K = 0.5) as a surfactant will result in compositions which are very mild, but which would require higher levels of proton donor agent and antimicrobial active to achieve the residual effectiveness of the present invention. Paraffinsulfonate, a commercial grade surfactant sold under the name Hastapur SAS® by Hoechst Celanese, with a small upper group and average chain length of 15.5 (K = 0.1) is a relatively active surfactant and provides a very high deposition of active . Compositions comprising lower levels of active and acid can be used with higher levels of paraffinsulfonate, wherein the surfactant provides a larger component of residual effectiveness. Alternatively, compositions comprising lower levels of paraffinsulfonate can be combined with still higher levels of active ingredient to achieve a smooth and effective composition. Moderately active levels can be used with the paraffinsulfonate, since its solubility index indicates that said compositions will have a very high deposition of the active. Non-limiting examples of 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 sulphonates having chain lengths predominantly 14 and 16 carbon atoms and paraffinsulfonates having chain lengths of 13 to 17 carbon atoms, and mixtures thereof. It is especially preferred to use ammonium sodium lauryl sulfate in the present; ammonium and sodium myristyl sulfate, lauret-1, lauret-2, lauret-3 and lauret-4 ammonium sodium sulfate; C14-C16 ammonium and sodium olefinsulfonates; C13-C17 paraffinsulfonates and mixtures thereof. It has been found that the non-anionic surfactants of the group consisting of nonionic surfactants, cationic surfactants, amphoteric surfactants and mixtures thereof, actually reduce the effectiveness benefits when used with anionic surfactants at high levels. This is more evident in the case of cationic and amphoteric surfactants in which it is believed that these surfactants interfere (charge-charge interaction) with the ability of the anionic surfactant to degrade the lipid in the membranes of the cell. The ratio of the amount of these anionic surfactants to the amount of anionic surfactant should be less than 1: 1, preferably less than about 1: 2, and most preferably less than about 1: 4. Rinse-off antimicrobial compositions for personal cleansing preferably do not comprise hydrotropic sulfonates, particularly terpenoid salts, or mono- or binuclear aromatic compounds such as camphor, toluene, xylene, eumeno and naphthalene sulfonates.
C. Proton donor agent The rinse-off antimicrobial compositions for personal cleansing of the present invention comprise about 0.1% to about 12%, preferably about 0.5% to about 10%, most preferably about 1% to about 7.5 %, and more preferably about 2.5% to about 5% based on the weight of the composition for personal cleansing, of a proton donor agent. "Proton donating agent" refers to any acidic compound or mixture thereof, which results in a non-dissociated acid on the skin after use. The proton donor agents can be organic acids, including polymeric acids, mineral acids or mixtures thereof.
Organic Acids The proton donor agents that are organic acids remain at least partially not dissociated in the concentrated composition and remain so when the compositions are diluted during washing and rinsing. The proton donor agent of organic acid must have at least a pKa value less than 5.5. These organic proton donor agents can be added directly to the composition in acid form or can be formed by the addition of the conjugate base of the desired acid and a sufficient amount of a separate acid strong enough to form the undissociated acid to from the base.biological activity index of organic acids The preferred organic proton donor agents are selected based on their biological activity. This activity is represented by an index of biological activity, Z, which is defined as: Z = 1 + 0.25pKa1 + 0.42logP. The biological activity index combines the dissociation characteristics and the hydrophobicity of the acid. It is important that the non-dissociated proton donating agent of the composition is deposited on the skin to reduce the negative charge on the cell wall. The dissociation constant of the acid, pKa-t, is indicative of the proton donor capacity of the chemical in relation to the pH of the medium to which it is incorporated. Since undissociated acid is most preferred in the composition, acids with higher pKas are generally more preferred for a given product pH. The octanol-water partition coefficient, P, represents the tendency of materials in solution to prefer oils or water. Essentially it is a measure of the hydrophobic nature of a material in solution: the higher the division coefficient, the more soluble in oil, and the less soluble in water the material will be. Since it is desired that the acids dissolved in the compositions arise from the aqueous cleaner after application, are deposited on the oil-based skin and remain during rinsing, the organic acids with higher octanol-water partition coefficients are the most preferred. Preferred organic proton donor agents of the rinse-off antimicrobial compositions for personal cleansing of the present invention have a biological activity index greater than about 0.75, preferably greater than about 1.0, more preferably greater than about 1.5. and more preferably greater than 2.0.
Mineral acids Proton donor agents that are mineral acids will not remain undissociated in the concentrated composition or when the compositions are diluted during washing and rinsing. Despite this, it has been discovered that mineral acids can be effective proton donors for use herein. Without being limited by theory, it is believed that strong mineral acids acidify the carboxylic and phosphatidyl groups in proteins of the skin cells, thereby providing acid not dissociated in situ. These proton donor agents can only be added directly to the composition in the acid form.
It is critical to achieve the benefits of the invention that the acid not disassociated from the proton donor agent (deposited or formed in situ) remains on the skin in the protonated form. Thus, the pH of the non-rinsing antimicrobial compositions of the present invention should be adjusted to a sufficiently low level in order to form or deposit substantial undissolved acid on the skin. The pH of the compositions should be adjusted and preferably regulated in the range from about 3.0 to about 6.0, preferably from about 3.5 to about 5.0 and more preferably from about 3.5 to about 4.5. A non-exclusive list of examples of organic acids that can be used as the proton donor 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, polyacrylic acid, its salts, and mixtures thereof. Especially preferred organic proton donor agents are the group consisting of malic acid, malonic acid, citric acid, succinic acid, and lactic acid. 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 since they cause less itching to the skin than other acids, may have a less negative impact on the skin than other acids and may contribute to a special rinsing sensation. which is preferred by some consumers. As used herein, the term "polymeric acid" refers to an acid with repeating units of carboxylic acid groups linked together within a chain. Suitable polymeric acids can include homopolymers, copolymers and terpolymers, but most contain at least 30 mol% carboxylic acid groups. Specific examples of suitable polymeric acids useful herein include poly (acrylic) acid and its copolymers, both ionic and non-ionic (for example, maleic-acrylic, sulfonic-acrylic and styrene-acrylic copolymers), the crosslinked polyacrylic acids having an molecular weight of less than about 250,000, preferably less than about 100,000 acids (-hydroxy), poly (methacrylic acid) and naturally occurring polymeric acids such as carragene, carboxymethylcellulose and alginic acid. It is especially preferred here to use the straight chain poly (acrylic) acids.
D. Deposition Auxiliary The rinseable liquid antimicrobial compositions for personal cleansing herein comprise about 0.1% to about 30%, preferably about 1% to about 30%, most preferably about 3% to about 25%, more preferably about 5% to about 25% of a deposition assistant. It has been found that compositions containing a deposition aid have improved antibacterial efficacy compared to compositions that 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 at least about 30%, most preferably at least about fifty%. Suitable deposition aids for use herein include, for example, lipophilic skin-moisturizing agents, cationic polymers, non-ionic polymers, zeolites, clays and mixtures thereof. One of the reasons why polymers are believed to be effective deposition aids is that they can form coacervates with the anionic surfactant. Suitable cationic and nonionic polymers for use as a deposition aid herein include polyethylene glycols, polypropylene glycols, hydrolyzed silk proteins, hydrolysed milk proteins, hydrolyzed keratin proteins, hydroxypropyltrimonium guar chloride, polyuats, silicone polymers and mixtures of the same. When cationic or non-ionic polymers are used as the deposition aid, they are used at levels ranging from about 0.1% to about 1.0%, preferably from about 0.15% to about 0.8%, most 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. In addition to providing improved antibacterial efficacy compared to compositions that do not contain a deposition aid, the lipophilic skin moisturizing agent provides a moisturizing effect to the user of the product for personal cleansing when the lipophilic skin moisturizing agent is deposited on the skin. user's skin When lipophilic skin-moisturizing agents are used as the deposition aid herein, they are employed at a level of from about 1% to about 30%, preferably about 3% to about 25%, most preferably about 5% to about 25% by weight of the composition. Two types of rheological parameters are used to define the lipophilic skin moisturizing agent used in the present. The viscosity of the lipophilic wetting agent of the skin is represented by consistency (k) and shear rate (n). The lipophilic skin moisturizing agents for use herein typically have a consistency (k) ranging from about 5 to about 5,000 poise, preferably about 10 to about 3,000 poise, most preferably about 50 to about 2,000 poise, as measured by the Consistency Method (k) described hereinafter in the Analytical Methods section. Lipophilic skin moisturizing agents suitable for use herein also have a shear rate (n) ranging from about 0.01 to about 0.9, preferably about 0.1 to about 0.5, most preferably about 0.2 to about 0.5, measured by the Cutting Stress Index Method described hereinafter in the Analytical Methods section. While not wishing to be bound by any theory, it is believed that lipophilic skin-moisturizing agents having rheological properties other than those defined herein are very easily emulsified and therefore not deposited, or they are very "difficult" to adhere to or deposit on the skin and provide a moisturizing benefit. In addition, the rheological properties of the lipophilic moisturizing agent of the skin are also important for the user's perception. Some lipophilic skin-moisturizing agents, when deposited on the skin, are considered too sticky or are not preferred by the user. In some cases, the lipophilic skin moisturizing agent may also desirably be defined in terms of its solubility parameter, as defined by Vauqhan in Cosmetics and Toiletries, Vol. 103, p. 47-69, October 1988. A lipophilic skin moisturizing agent having a Vaughan solubility parameter (VSP) of 5 to 10, preferably of 5.5. to 9 is suitable for use in the liquid compositions for personal cleansing herein. A wide variety of lipid-type materials and mixtures of materials are suitable for use in the anti-microbial compositions for personal cleansing of the present invention. Preferably, 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 non-digestible oils, such as those described in US patents 3,600,186 to Mattson; Issued on August 17, 1971 and 4,005, 195 and 4,005,196 to Jandacek and others; both issued on January 25, 1977, all of which are incorporated herein by reference, or mixtures of digestible or non-digestible liquid oils with solid polyol polyesters such as those described in U.S. Pat. 4,797,300 to Jandacek; Issued on January 10, 1989; the patents of E.U.A. 5,306,514 and 5,306,516 and 5,306,515 to Letton; all issued on April 26, 1994, all of which are incorporated herein by reference, and esters of acetoglyceride, alkyls esters, alkenyl esters, lanolin and its derivatives, milk triglycerides, wax esters, wax derivatives bee, sterols, phospholipids and mixtures thereof. Fatty acids, fatty acid soaps and water soluble polyols are specifically excluded from this definition of a lipophilic skin moisturizing agent.
Oils and waxes of hydrocarbon: Some examples are petrolatum, microcrystalline waxes of mineral oil, polyalkenes, (polybutene and hydrogenated polydecene and not hydrogenated), paraffin, cerasin, ozokerite, polyethylene and perhydrosqualene. Mixtures of hydrogenated and non-hydrogenated high molecular weight petrolatum and polybutenes in which the ratio of petrolatum to polybutene is in the range of 90:10 to 40:60 are also suitable for use as the lipid wetting agent of the skin in the compositions of the present.
Silicone oils: Some examples are dimethicone copolyol, dimethyl polysiloxane, diethyl polysiloxane, high molecular weight dimethicone, mixed C1-C30 alkylpolysiloxane, phenyldimethicone, dimethiconol and mixtures thereof. More preferred are the non-volatile silicones selected from dimethicone, dimethiconol, mixed C1-C30 alkyl polysiloxane, and mixtures thereof. Non-limiting examples of silicones useful herein are described in the U.S.A. No. 5,01 1, 681 to Ciotti et al., Dated April 30, 1991, which is incorporated by reference.
Di- and tri-glycerides: Some examples are castor oil, soybean oil, derived soybean oils such as maleated soybean oil, sunflower oil, cottonseed oil, corn oil, hazelnut oil, peanut oil, oil. olive, cod liver oil, almond oil, avocado oil, palm oil and sesame oil, vegetable oils and vegetable oil derivatives; coconut oil and derived coconut oil, cottonseed oil and derived cottonseed oil, jojoba oil, cocoa butter and the like.
The acetoqlyceride esters are used and one 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, ricinoleate lanolin alcohol. It is more preferred when at least 75% of the lipophilic skin conditioning agent comprises lipids selected from the group consisting of: petrolatum, mixtures of high molecular weight petrolatum and polybutene, mineral oil, liquid non-digestible oils (for example, octaesters of sucrose of liquid cottonseed) or blends of liquid digestible or non-digestible oils with solid polyol polyesters (eg, sucrose octaesters prepared from C22 fatty acids) in which the ratio of digestible or non-digestible liquid oil to solid polyol polyester is in the range of 96: 4 to 80:20, hydrogenated or non-hydrogenated polybutene, microcrystalline wax, polylakene, paraffin, waxen, ozokerite, polyethylene, perhydrosqualene; dimethicones, alkyl siloxane, polymethylsiloxane, methylphenylpolysiloxane and mixtures thereof. When used as a mixture of petrolatum and other lipids, the ratio of petrolatum to the other selected lipids (hydrogenated or non-hydrogenated polybutene or polydecene or mineral oil) is preferably from 10: 1 to 1: 2, more preferably from 5: 1 to eleven .
E. Water The non-rinsing liquid antimicrobial compositions of the present invention comprise water in a ratio of about 35% to about 98.8%, preferably about 45% to about 98%, most preferably about 55% to about 97.5% and more preferably around 65% to approximately 95.99%. The solid stick embodiments of the present invention comprise water in a proportion of from about 2% to about 25%, most preferably about 3% to about 20% and more preferably about 55 to about 15%. The rinsing antimicrobial liquid compositions for personal cleansing of the present invention preferably have an apparent or concentrated viscosity of from about 500 cps to about 60,000 cps at 26.7 ° C, preferably from 5,000 to 30,000 cps. The term "viscosity", as used herein, refers to viscosity as measured by a Brookfield RVTDCP with a CP-41 spindle at 1 RPM for 3 minutes, unless otherwise indicated. The "concentrated" viscosity is the viscosity of the undiluted liquid cleaner.
F. Optional ingredients that are preferredSoftness improvers In order to achieve the required softness of the present invention, optional ingredients may be added to improve softness to the skin. These ingredients include cationic and non-ionic polymers, surfactant coagents, humectants and mixtures thereof. Polymers useful herein include polyethylene glycols, polypropylene glycols, hydrolyzed silk proteins, hydrolyzed milk proteins, hydrolyzed keratin proteins, hydroxypropyltrimonium guar chloride, polyuats, silicone polymers, and mixtures thereof. When used, the softness improving polymers comprise from about 0.1% to about 1%, preferably from about 0.2% to about 1.0% and most preferably from about 0.2% to about 0.6%, by weight of the rinsable antimicrobial composition. for personal cleansing, of the composition. Surfactant coagents useful herein include nonionic surfactants such as the Genapol® 24 series of ethoxylated alcohols, POE (20) sorbitan monooleate (Tweéri® 80), polyethylene glycol cocoate, and propylene oxide / ethylene oxide block polymers. Pluronic®, and amphoteric surfactants such as alkylbetaines, alkylsultaines, aicylamphoacetates, alkylalaphodiacetates, alkylamphopropionates and alkylalanophodipionates. When used, cosolvents comprise about 20% to about 70%, preferably about 20% to about 50%, by weight of the anionic surfactant, of the composition for personal cleansing.
Stabilizers When a lipophilic skin-moisturizing agent is used as the softness improver in the liquid antimicrobial compositions herein, a stabilizer may also be included at a level ranging from 0.1% to about 10%, preferably about 0.1% a about 8%, most preferably about 0.1% to about 5% by weight of the composition. The stabilizer is used to form a crystalline stabilizing network in the liquid composition for personal cleansing that prevents the droplets of lipophilic skin moisturizing agent from colliding and separating into phases in the product. The network exhibits viscosity recovery that depends on the time after the shear (for example, thixotropy). The stabilizers used herein are not surfactants. The stabilizers provide improved shelf stability and tension, but allow the liquid personal cleansing composition to separate after foaming, and thus provide for the increased deposition of the lipophilic skin moisturizing agent on the skin. The foregoing is particularly true when the cleaning emulsions of the present invention are used in conjunction with a polymeric diamond mesh sponge implement as described in Campagnoli; patent of E.U.A. 5,144,744; issued on September 8, 1992, incorporated herein by reference. In one embodiment of the present invention, the stabilizer employed in the personal cleansing compositions herein comprises a crystalline hydroxyl-containing stabilizer. This stabilizer may be a water-insoluble wax substance of fatty acid, fatty ester or fatty soap containing hydroxyl, or the like. The crystalline hydroxy-containing stabilizer is selected from the group consisting of: (i) CHZ-ORTCH - OR2CH2 - OR,where ORi is -C-R4 (CHOH) xR5 (CHOH) and R6; R2 is Ri or H R3 is Ri or H R4 is Co-20 alkyl Rs is Co-20 alkyl, Re is Co-20 alkyland where 1 < x + y < 4;(or)ORII R7-C-OMwherein R7 is -R4 (CHOH) xR5 (CHOH) and R6 M is Na +, k + or Mg + * or H; and i ??) mixtures thereof. 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.
When said hydroxyl-containing crystalline stabilizers are used in the personal cleansing compositions herein they are typically present at from about 0.1% to 10%, preferably from 0.1% to 8%, most preferably from 0.1% to about 5%. % of liquid compositions for personal cleaning. The stabilizer is insoluble in water under ambient to near ambient conditions. Alternatively, the stabilizer employed in the personal cleansing compositions herein may comprise a polymeric thickener. When polymeric thickeners are used 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 modified 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. acrylic and / or methacrylic acid derivatives, anionic, cationic and nonionic cellulose resins, cationic copolymers of dimethyldialkyl chloride and acrylic acid, cationic homopolymers of dimethylalkylammonium chloride, cationic polyalkylene and ethoxy-pipolykyleneimines, polyethylene glycol with a molecular weight of 100,000 to 4,000,000 and mixtures thereof. Preferably, the polymer is selected from the group consisting of sodium polyacrylate, hydroxyethylcellulose, cetylhydroxyethylcellulose and polyquaternium 10. Alternatively, the stabilizer employed in the personal cleansing compositions herein may comprise fatty acid esters of C 10 -C 22 ethylene glycol. . C10-C22 ethylene glycol fatty acid esters can also be desirably used in combination with the polymeric thickeners described above. The ester is preferably a diester, most preferably a C 14 -C 18 diester, more preferably ethylene glycol distearate. When the C10-C22 ethylene glycol fatty acid esters are used as the stabilizer in the personal cleansing compositions herein, typically from about 3% to about 10%, preferably from about 5% to about 8, are present. %, most preferably around 6% to about 8% of the compositions for personal cleansing. Another class of stabilizer that can be employed in the personal cleansing compositions of the present invention comprises dispersed amorphous silica selected from the group consisting of fuming silica and precipitated silica and mixtures thereof. As used herein, the term "dispersed amorphous silica" refers to small, finely divided, non-crystalline silica having an average particle size of agglomerate less than 100 microns. Fuming silica, which is also known as ground silica, is produced by the hydrolysis of the vapor phase of silicon tetrachloride in a hydrogen oxygen flame. It is believed that the combustion process creates silicon dioxide molecules that condense to form particles. The particles collide, unite and concretize together. The result of this process is a three-dimensional branched chain aggregate. Once the aggregate cools below the melting point of the silica, which is about 1710 ° C, additional shocks result in the mechanical entanglement of the chains to form agglomerates. The precipitated silicas and the silica gels are generally made in aqueous solution. See, Cabot Tehcnical Data Pamphlet TD-100 entitled "CAB-O-SIL® 'Untreated Furned Silica Properties and Functions," October 1993 and Cabot Technical Dat Pamphlet TD-104 entitled "CAB-O-SIL® Fumed Silica in Cosmetic and Personal Care Products ", March 1992, both of which are incorporated herein by reference. The fumed silica preferably has an average particle size of agglomerate in the range of about 0.1 microns to about 100 microns, preferably about 1 micron to about 50 microns and most preferably about 10 microns to about 30 microns. The agglomerates are composed of aggregates having an average particle size in the range of about 0.01 microns to about 15 microns, preferably about 0.05 microns to about 10 microns, most preferably about 0.1 microns to about 5 microns and more preferably about 0.2 microns to approximately 0.3 microns. The silica preferably has a surface area of more than 50 m2 / gram, preferably more than 130 m2 / gram, most preferably greater than 180 m2 / gram. 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 about 0.25% to about 8%, most preferably about 0.5. % to approximately 5%. A fourth class of stabilizer that can be used 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 that contains sodium, magnesium, lithium, silica, oxygen, hydrogen and fluorine. See Merck Index, eleventh edition, 1989, entry 4538, p. 729, which is incorporated in the present by way of reference. When smectite clay is used 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 about 0.25% to about 8% and most preferably about from 0.5% to approximately 5%.
Other known stabilizers, such as fatty acids and fatty alcohols, can also be used in the present compositions. Palmitic acid and lauric acid are especially preferred for use herein.
G. Other Optional Ingredients The compositions of the present invention may comprise a wide range of optional ingredients. The CTFA International Cosmetic Ingredient Dictionary, Sixth Edition, 1995, which is incorporated herein by reference in its entirety, discloses a wide variety of non-limiting cosmetic and pharmaceutical ingredients commonly used in the skin care industry, which are suitable for use in the compositions of the present invention. Non-limiting examples of functional classes of ingredients are described on page 537 of this reference. Examples of these functional classes include: abrasives, anti-acne agents, cake antiforming agents, antioxidants, binders, biological additives, volumetric 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 whitening agents, skin conditioning agents, (emollients, humectants, various, and occlusives), protective of the skin, solvents, foam impellers, hydrotropes, solubilizing agents, suspending agents (non-surfactants), sunscreen agents, ultraviolet light absorbers and agents to increase viscosity (aqueous and non-aqueous). Examples of other functional classes of materials useful herein that are well known to one skilled in the art include solubilizing, sequestering, and keratolytic agents and the like.
II.- Characteristics The rinsing antimicrobial compositions for personal cleansing of the present invention have the following characteristics.
A. Residual Effectiveness Index Against Gram-negative Organisms The rinse-resistant antimicrobial compositions for personal cleansing of the present invention have a Gram negative Residual Effectiveness Index greater than 0.3 (50% reduction), preferably greater than 1.0 (90% reduction). ), more preferred greater than 1.3 (95% reduction) and even more preferred, greater than 1.7 (98% reduction). The Gram Negative Residual Effectiveness Index is measured by the In Vivo Residual Effectiveness Test in Escherichia coli described hereinafter in the Analytical Methods Section. The index represents a difference in the logarithmic values of base 10 of the concentrations of bacteria between a test sample and a control. For example, an index of 0.3 represents a reduction in logarithmic values of 0.3 (Alog = 0.3) which in turn represents a 50% reduction in the bacterial count.
B. Smoothness Index The rinse-off antimicrobial compositions for personal cleansing of the present invention have a Smoothness index greater than 0.3, preferably greater than 0.4 and more preferred greater than 0.6. The Softness Index is measured by the Controlled Forearm Application Test (FCAT) described hereinafter in the Analytical Methods section.
III. Methods of making the rinseable antimicrobial compositions for personal cleansing The rinseable antimicrobial compositions for personal cleansing of the present invention are made by techniques recognized in the art for the various forms of personal cleansing products.
IV. Methods for using the rinseable antimicrobial composition for personal cleansing The rinseable antimicrobial compositions for personal cleansing of the present invention are useful for personal cleansing, especially for cleaning hands. Typically, an appropriate or effective amount of the cleaning composition is applied to the area to be cleaned. Alternatively, an appropriate amount of the cleaning composition can be applied by application by means of a washcloth, sponge, pad, cotton piece, foamed device or other device for application. If desired, the area to be cleaned can be previously moistened with water. The compositions of the present invention are combined with water during the cleaning process and rinsed from the skin. Generally, an effective amount of product to be used will depend on the needs and habits of use of the individual. Typical amounts of the present compositions useful for cleaning are in the range of 0.1 mg / cm2 to 10 mg / cm2, preferably 0.3 mg / cm2 to 3 mg / cm2 of skin area to be cleaned.
Test analytical methodsMicrotox Response Test Reference: Microtox Manual: A Toxicity Testing Handbook, 1992 Volumes l-IV; Microbics Corporation. Equipment: Microtox M500 Toxicity Test Unit; Microbics Corporation. Connected to a computer for the acquisition and analysis of data in accordance with the previous reference.
Procedure 1 Preparation of the Sample Reserve Solution (standard concentration: 1,000 ppm) The reserve solution of the test anionic surfactant sample is prepared and used as a stock solution from which all the samples are made. other dilutions. The standard "initial concentration", the highest concentration to be tested, is 500 ppm. (If an initial concentration of 500 ppm fails to give a calculable result, for example, an active surfactant kills all reagents at any dilution, the initial concentration can be adjusted based on the known range of EC50 values of the surfactants. previously evaluated). The reserve solution is prepared at twice the initial concentration. a) 0.1 g (or the adjusted amount if required) of anionic surfactant, which counts for the raw material activity, is added to the beaker. b) Microtox diluent (2% NaCI, Microbios Corp.) is added to complete 100 g. c) The solution is stirred to ensure that it is mixed properly.
Reconstitution of the Microtox reagent and preparation of the test a) Turn on the test unit and allow the temperature of the cavity for the reagent to equilibrate to 5.5 ° C and for the incubator to lock and read the temperature of the cavity to equilibrate at 15 ° C. b) A clean cuvette (Microbics Corp.) is placed in the reagent cavity, and filled with 1 .0 ml of the Microtox Reconstitution Solution (distilled water, Microbics Corp.). Allow to cool for 15 minutes. c) The standard reagent bottle for Acute Toxicity Microtox (Vibrio fischerio, Microbics Corp.) is reconstituted, adding 1 .0 ml of the cold solution for reconstitution to the reagent bottle. d) The solution is stirred in the reagent bottle for 2-3 seconds, then the reconstituted reagent is poured back into the cold cuvette and the bottle is returned to the cavity for the reagent. Allow to stabilize for 15 minutes. e) Place 8 cuvettes containing 500 μl of the Microtox Diluent, as a test, in the cavities of the incubator of the test unit. Allow to cool for 15 minutes.
Dilution of the test substance 7 serial dilutions of the test substance are prepared from the sample reserve solution. The final volume of all the buckets should be 1 .0 mi. a) Place 8 empty buckets in a rack for test tube. b) Add 1 .0 ml of the Microtox Diluent solution to tubes 1-7. c) 2.0 ml of the sample reserve solution (1000 ppm) are added to the cuvette 8. d) 1 .0 ml of the solution from the cuvette 8 are transferred to the cuvette 7 and the cuvette 7 is mixed. e) 1.0 ml of the newly formed solution is transferred in series to the next cell (7 to 6, 6 to 5, etc.). Remove 1 .0 ml of the solution from cell 2 and discard. Bucket 1 is the piece that contains only Microtox Thinner. The cuvettes are placed in the incubator cavities of the test unit keeping them in order from lowest to highest concentration. These buckets should correspond to the 8 buckets prepared in step 2 above. Allow to cool for 15 minutes.
Evaluation and Bioluminescence Test of the Sample a) Add 10 μl of the reconstituted reagent to the 8 previously cooled cuvettes of the test prepared in step 2 above (containing 500 μl of diluent). 15 minutes are allowed for the reagent to stabilize. b) The Microtox Data Capture and Reporting software (Microbics Corp.) is started, START TESTING is selected, enter the name and description of the file, the correct initial concentration in ppm (500 ppm if the standard concentration is used) and the number of controls (1) and dilutions (7). Time 1 must be selected as 5 minutes, time 2 is NONE. Press the ENTER key and then the spacebar to start the test. c) Place the test cuvette containing the reagent which corresponds to the test piece in the reading cavity and press SET. After the cuvette comes back to the surface, READ is pressed and the value will be captured by the computer. d) Similarly, the remaining 7 cells containing the reagent are read when requested by the computer by pressing the READ button with the correct cell in the cavity for reading. e) After the initial 8 readings have been taken, 500 μl of the diluted test substance is transferred to its corresponding cuvette containing the reagent. It is mixed with swirling or shaking action and returned to the incubation cavities. The computer will count for 5 minutes and indicate that the final readings begin.f) The final readings are taken by placing the correct cuvette containing the reagent and the diluted test surfactant in the reading cavity and pressing READ when requested by the computer.
. Analysis of data _ __ __ _ _The concentration of the test substance, in ppm, can be calculated by decreasing the bioluminescence of the Acute Microtox Toxicity Reagent by 50% from the initial value (EC50 value) using the Run Statistics on Data File option of the Microtox Software (recommended ) or conducting a linear regression of the data (% reduction vs. logarithm of the concentration). The% of reductions is calculated using the following formulas:Final reading of the reagent piece = Correction factor Initial reading of the reagent partFinal reading of the reagent with diluted test substance = Reduction factorx Initial reading of the reagent with diluted test substancewhere x means a corresponding concentration Correction factor - Reduction factor Reduction% = Correction factor The Microtox index is the EC50 value in ppm. Descent of solubility, K Equipment: Liquid Flash Counter equipped with correct extinction curve for the liquid flash fluid used (Ultima Gold, Packard Instruments Co)Preparation of Triclosan® Marked with C14 a) Add 5.00 g of regular triclosan powder (TCS) to a 20 ml bottle. b) 10 μCi of 14C TCS and one ml of acetone are added. c) The solution is stirred for 3 minutes or until the entire TCS is dissolved. d) A stream of N2 is introduced to remove most of the solvent until it solidifies again. e) The solid is ground to powder and dried under N2 overnight to obtain the marked material ready to be used. f) The activity of TCS in DPM / g is measured to use it as a correction factor for subsequent samples. 1.- 0.1 g of powdered TCS (weight is recorded) from step e above in the flask in liquid is placed. 2.- 10 ml of flash fluid is added in liquid (Ultima Gold).3. - They are placed in the flash counter in liquid and count the degradations per minute (DPM) of the sample. 4.- DPM is divided between the weight of TCS from step 1 - f-1 to determine the correction factor (DPM / g of TCS).
Solubility protocol a) Prepare the reserve solution of the formula without TCS with 16% level of anionic surfactant in tap water with a hardness of 454-583 mg. b) 8 empty buckets are placed in a test tube rack. c) 3 ml of the reserve solution is added to a flask 1. d) Prepare 5 individual solutions of 3 ml, which are 1: 2, 1: 4, 1: 8, 1: 16 and 1: 32 dilutions of the reserve solution, in 5 flasks (final concentrations are 8 %, 4%, 2%, 1% and 0.5%). e) 0.05 g of radioactively labeled TCS (from step 1 -e above) and a magnetic stirring bar are added to each vial. The bottles are shaken as a group for at least 2 hours. If the solid phase of TCS disappears, additional TCS is added to ensure phase balance.a) For most surfactants, the slope of the solubility curve between 1% and 2% surfactant is representative of K. b) For some surfactants the curve of maximum solubility of TCS remains linear outside the region of 1-2% surfactant. In that situation, K should be calculated from this complete linear region, such as at levels of 0-4%, 1 -4% or 0.5-2% surfactant. It is important that K is calculated close to the 2% surfactant range since this is an approximate concentration of surfactant in a dilute cleaning composition.
Residual effectiveness in vivo on E. coli References: Aly, R; Maibach, H. I .; Aust, L.B .; Corbin, N. C; Finkey,M.B. 1994. 1 .- In vivo effect of antimicrobial soap bars containing 1.5% and 0.8% trichlorocarbanilide against two strains of pathogenic bacteria. J. Soc. Cosmet. Chem., 35, 351-355, 1981. 2.- In vivo methods for treating topical antimicrobial agents. J. Soc. Cosmet. Chem., 32, 317-323, 1981.
Test design The following method quantifies the Antibacterial Residual Effectiveness of antimicrobial products in liquid form and bar soap. The reductions are reported from a control, a placebo of non-antibacterial soap, without additional treatment, which is used in the forearms of the subjects. By definition, the antibacterial placebo will not show residual effectiveness in the test.
Pre-test phase _ __ The test subjects were instructed not to use antibacterial products for 7 days before the test. Subjects' hands were examined just prior to the test for separate cuts / skin that could prevent them from participating in the test.
Washing procedure a) Both forearms are washed with the control soap once to remove any of the transient bacteria or contaminants. Rinse and dry the forearms. b) The test monitor wets the gloved hands, places 1.0 ml of the test liquid product (the bar treatments are done in accordance with the previous references) on the forearm of the subject, and soaps the flexion area of the forearm with the hand for 45 seconds. c) Afterwards, the forearms of the subjects are rinsed with tap water at a temperature of 32.2-37.7 ° C and at a speed of 3,785 LPM (liters per minute) for 15 seconds. d) Steps b-c are repeated 2 times (total of 3 washes) for the test product. e) The arm is dried without rubbing with a paper towel and the test sites are marked (circles of approximately 8.6 cm2 with a rubber seal) f) The complete procedure (ae) is repeated on the other forearm of the subject with the product of control.
Inoculation procedure a) The inoculum of E. coli (ATCC 10536, developed from freeze-dried stock in soy-casein broth at 37 ° C for 18-24 hours) was adjusted to a concentration of approximately 108 organisms / ml (0.45) of transmitence vs TSB target in the spectrophotometer) b) Each test site is inoculated with 10 μl of E. coli. The inoculum is disseminated with a loop for inoculation in a circle of approximately 3 cm2 and covered with a Hilltop camera (Hilltop Research Inc.).c) This procedure is repeated for each test site on each forearm.
Sampling the bacteria (extraction procedure) a) Prepare the sampling solution with 0.04% KH2P04, 1.01% Na2HP04, 0.1% Triton X-100, 1.5% Polysorbate 80, 0.3% lecithin in water, the pH is adjusted to 7.8 with 1 N HCl. b) Exactly after 60 minutes of inoculation, the Hilltop chamber is removed from the site in which the sample is to be taken. A sample cup of 8.6 cm2 is placed on the site. c) 5 ml of the sampling solution is added to the cup. d) The bacteria are extracted by gently rubbing the site with a glass gendarme for 30 seconds. e) The sampling solution is removed with a pipette and placed in a labeled test tube. f) The extraction is repeated with 5 ml of the sampling fluid. The complete extraction procedure is repeated for each of the sites 60 minutes after the inoculation.
Bacteria quantification a) Phosphate buffer solution is prepared with 0.1 17% Na2HP04, 0.022% NaH2P04 and 0.85% NaCl, adjust the pH to 7.8 with 1 N HCl.b) 1 .1 ml of the test solution are removed aseptically from the test solution, 0.1 ml of which is seeded by striae on trypticase-soy agar containing 1.5% Polysorbate 80. The remaining milliliter (1 ml) is place in 9 ml of sterile phosphate buffer to achieve a 1: 10 dilution of the sample solution. This procedure is repeated 3 times more (each dilution of the series). c) The plates are inverted and incubated for 24 hours at 35 ° C. d) The colonies formed in the plates are then counted and the results are calculated by multiplying the counts by the dilution factor (original sample = 10, first dilution = 100, second dilution = 1, 000, etc.) and the final results are report as the number of colony forming units per milliliter (CFU / ml).7. Calculation of the Residual Effect Index against Negative Gram Organisms = log- | 0 (CFU / ml of the placebo site) - log? 0 (CFU / ml of the test product site)Controlled application test on the forearm (FCAT)Reference: Ertel, K.D., et al .; "A Forearm Controlled Application Technique for Estimating the Relative Mildness of Personal Cleansing Products"; J. Soc. Cosmet. Chem. 46 (1995) 67-76.
The Controlled Forearm Application Test, or FCAT, is a comparative test that discriminates the differences in the smoothness of the product towards the skin. A test product is compared to a control cleaning bar that has a standard soap base.
Test group restrictions Test groups of 20-30 subjects, 18 to 55 years of age, are used who wash regularly with soap. Excluded are potential subjects who have (1) an initial degree of dryness of 3.0 or greater in the forearms as assessed during the initial examination, (2) skin cancer, eczema or psoriasis on the forearms, (3) are receiving injectable insulin, (4) are pregnant or in the lactation stage or (5) are receiving treatment for contact allergy skin problems. The subjects should avoid hot water baths, swimming and sun lamps and should avoid applying any soap, cleansing products, creams or gels to the forearms during the duration of the study. Subjects should keep their forearms without getting wet at least two hours before the grading process. The studies are executed using a randomized, blinded product order format. The clinical assistant should verify the correct sequence of treatment and document it before washing each subject. The products are applied to the forearms a total of nine (9) times: two (2) times daily for the first four (4) days of the study and one (1) time on the last day. Visits to the washing test facility must be separated by a minimum of three (3) hours.
All clinical assistants should wear disposable gloves during the washing procedure, rinsing them between treatments and changing them between subjects.
Control product The control product is a compressed bar soap containing: 56.1% sodium sebalate 18.7% sodium cocoate 0.7% sodium chloride 24% water 0.5% minor ingredients (perfume, impurities)Product application procedure Both test and control products are tested in the same arm. The following test procedure is used. 1 . Subjects wet the total area of the flex areas of their forearms with tap water at 32.2-37.7 ° C keeping the arm briefly under the water jet. 2. A clinical assistant dips a quarter leaf (approximately 20.3 cm x 15.24 cm) of Masslinn ® towel with tap water, then squeezes the towel gently to remove excess water. A clinical assistant applies the products to the arm, starting with the product designated for the site closest to the elbow, using the appropriate procedure as follows:Liquid product a. 0.1 cc of the test product is dispensed with a syringe in the center of the appropriately marked area. b. Two fingers of the gloved hand (latex) are wetted under the stream of water (index and middle fingers). c. Wet fingers are moved in a circular motion over the application site for 10 seconds to lather the product. d. Soaping remains on the application site for 90 seconds, then rinsed with the water jet of the tap for 15 seconds, taking care not to wash and soaping the adjacent sites. After 10 seconds of the rinse has finished, the clinical assistant will gently rub the site being rinsed with both gloved fingers for the remaining 5 seconds of rinsing.
Product in bar a. Two fingers of the gloved hand (latex) are wetted under the stream of water (index and middle fingers).b. The bar is wetted by holding it briefly under the water jet. The test bars should be wetted under running water at the start of each day. c. Wet fingers are rubbed in a circular motion on the surface of the bar for 15 seconds to form suds on the bar and fingers. d. Soaped fingers are rubbed on the application site in a circular motion for 10 seconds to lather the product on the skin. and. The soaping remains on the application site for 90 seconds, then it is rinsed with the water jet from the tap for 15 seconds, taking care not to wash the lathering of the adjacent sites. After 10 seconds of the rinse has finished, the clinical assistant will gently rub the site being rinsed with both gloved fingers for the remaining 5 seconds of rinsing.
Products in towel a. The towel is folded in half crosswise and the towel is gently rubbed in a circular motion within the appropriate area. b. The site is allowed to air dry for 90 seconds. Do not rinse the site.
Non-rinsable product a. 0.10 cc of the test product is dispensed with a syringe in the center of the appropriate marked area. b. Move your gloved fingers in a circular motion over the application site for 10 seconds. c. The site is allowed to air dry for 90 seconds. Do not rinse the site. 4. While waiting for 90 seconds of residency time to expire, the above procedure will be repeated over the remaining application site in that arm, treating the arm downward toward the wrist. 5. Steps 1-4 are repeated in the appropriate test areas so that two product applications are made to the test areas. 6. After the product has been applied twice to all areas of application, the clinical assistant dries gently without rubbing the subject's arm with a disposable paper towel.
Evaluation An expert grader evaluates the skin of each treatment area in the baseline and three hours after the final wash of the study. The treatment areas are evaluated under a 2.75x magnification (Magnification LampIlluminated Luxo model KFM-1A, Marshall Industries, Daytona, Ohio) with controlled lighting (8"Cool White Fluorescent Focus, 22 watts Circuline from General Electric). An expert grader evaluates the skin in terms of dryness and assigns a score taking as a basis the definitions indicated below TABLE 1Forearm graduation scale Scoring Skin dryness 0 No dryness 1 .0 Patches of lightweight powderiness and occasional patches of small scales can be observed. 2.0 Generalized lightweight pulvurulence. Initial cracking or lifting of small scales may be present. 3.0 Moderate generalized pulvurgency and / or severe cracking and raised scales. 4.0 Severe generalized severe and / or severe cracking and raised scales. 5.0 Generalized severe cracking and raised scales. An eczema type change may be present. Pulvurulence may be present but it is not prominent. You can see cracks with blood. 6.0 Generalized severe cracking. An eczema type change may be present. Cracks with blood may occur. Large scales may start to disappearThe FCAT test usually only produces mild to moderate irritation of the skin; however, if a treated site reaches a score of 5.0 or higher, at any time during the study, the treatment of all sites in that subject must be stopped.
Data At the end of the test the following values are determined after all the subjects have been evaluated: Reo = The average score of the control product area in the baseline. Ref = The average score of the control product area at the end of the test. Rt0 = The average score of the test product area in the baseline. Rtf = The average score of the test product area at the end of the test. There are many external conditions that could influence the FCAT test, such as relative humidity and water softness. The test is valid only if sufficient response is observed on the skin to the control product. The response to control must be greater than 1.0 (ie Ref - Rc0 >; 1.0) for the test to be valid. Given a valid test, the Softness Index of the test product is the difference in skin responses to the two products.
Softness index = (Ref - Rc0) - (Rtf - Rt0) Consistency (k) and shear rate (n) of lipophilic skin moisturizing agent Carrimed CSL 100 controlled tension rheometer was used to determine the stress index shear, n, and the consistency, k, of the lipophilic skin moisturizing agent used herein. The determination was carried out at 35 ° C with the cone measuring system of 2 ° of 4 cm typically established with a space of 51 microns and was carried out by the programmed application of a shear stress (typically from 0.6 dynes / square centimeter up to 5,000 dynes / square centimeter) for a period. If said tension results in a deformation of the sample, ie deformation of the measurement geometry of at least 10-4 rad / sec, then said deformation velocity will be reported as a shear rate. These data were used to create a viscosity flow curve μ Vs. Shear rate? for the material. Said flow curve could then be modeled in order to provide a mathematical expression that describes the behavior of the material within the specific limits of the shear stress and shear velocity. These results were adjusted with the following model of well-accepted exponent law (see for example: Chemical Enqineering, by Coulson and Richardson, Pergamon, 1982 or Transport Phenomena by Bird, Stewart and Lightfoot, Wiley, 1960): Viscosity, μ k ( 7 nl Viscosity of the liquid composition for personal cleansing The Wells-Brookfield cone / plate viscometer model DV-II + was used to determine the viscosity of the rinse-resistant antimicrobial cleaning compositions herein.The determination was carried out at 25 °. C with the cone measuring system of 2.4 cm ° (Spindle CP-41) with a gap of 0.013 mm between the two small pins in the respective cone and plate The measurement was carried out by injecting 0.5 ml of the sample that was It will analyze between the cone and the plate and rotating the cone at a fixed speed of 1 rpm.The resistance to rotation of the cone produces a torque that is proportional to the shear stress of the cone. e the liquid sample. The amount of torque was read and computed by the discometer in units of absolute centipoises (mPa's) based on the geometric constants of the cone, the rotation speed, and the tension related to the torque.
EXAMPLESThe following examples describe additionally and demonstrate embodiments within the scope of the present invention. In the following examples, all ingredients are listed at an active compound level. The examples are given solely for the purpose of illustration and should not be considered as limitations of the present invention, since many variations thereof are possible without departing from the spirit and scope of the invention. The ingredients are identified by the chemical or CTFA name. Component of EXAMPLE 1 EXAMPLE 2 EXAMPLE 3 liquid soap for hands% by weight% by weight% by weightLauret-3 ammonium sulfate 9.5 5.5 6.6Ammonium lauryl sulphate 3.2 2.9 3.1Sodium lauroamphoxide 5.4 5.6 5.0Anhydrous citric acid 6.3 6.3 0.00Polyacrylate * 0.00 0.00 8.00Triclosan 0.6 0.5 0.50Petrolatum 16.5 12.0 12.0Trihydroxyesteanna 0.15 0.15 0.25Lauric acid 1.0 1.5 1.5JR30M 0.6 0.1 0.0Polyquaternium-10 0.0 0.0 0.1Sodium hydroxide 0.0 0.0 to pH 4.0Sodium citrate at pH 3.9 to pH 3.9 0.0Miscellaneous 2.2 1.2 1.33Water CS CS CS K value of anionic surfactant < 0.4 < 0.4 < 0.4Microtox of anionic surfactant 1/150 1/150 1/150Biological activity (Z) of acid 1.29 1.29 * The polyacrylate is K7058 sold by B.F. Goodrich All liquid hand soaps shown have a Residual Effectiveness Index Against Gram Negative Organisms of more than approximately 0.3 and a Softness Index of more than approximately 0.3.
K value of anionic surfactant < 0.4 < 0.4 < 0.4Microtox of anionic surfactant 1/150 1/150 1/150Biological activity (Z) of acid 1.29 1.29 * The polyacrylate is K7058 sold by B.F. Goodrich All liquid hand soaps shown have a Residual Effectiveness Index Against Gram Negative Organisms of more than approximately 0.3 and a Softness Index of more than approximately 0.3.
Shower gels have a Residual Effectiveness Index Against Gram Negative Organisms greater than approximately 0.3; and a Softness index greater than 0.3.
Procedure for making fertilizers for hands and shower gels 1. Examples of hand soap 1 and 2 and examples of shower gel 2 and 3 All ingredients except petrolatum, active compound and perfume are added together and heated to the point necessary to melt the stabilizer (approximately 87.7 ° C for trihydroxystearin). It is cooled to less than 46.1 ° C and the active compound, petrolatum and perfume is added. The pH is adjusted with NaOH or buffer salt. The remaining water is added to complete the product.2. Example of shower gel 1 Wetting oils and surfactant coagents are added together and the ingredients are heated to 54.4-60 ° C until dissolved. In another container, primary surfactants, acid, pH regulating salt, preservatives, viscosity improver (salt) and polymer are added. Heat to 54.4-60 ° C until dissolved. The two mixtures are combined (or a single mixture is used if oils are not present), when both are at 54.4-60 ° C, then cooling is started. When the mixture is below 46.1 ° C, the antibacterial active compound and perfume is added. The final pH is adjusted using NaOH or the remaining buffer pH. The remaining water is added to complete the product.