Liquid hand soaps and body washes

Abstract

The disclosure provides a liquid hand soap or body wash, comprising (i) a surfactant system comprising C.sub.8-18 alkyl-ether sulfate, cocamidopropyl betaine (CAPB), and N-(2 hydroxyethyl) fatty acid amide; (ii) a polyethylene oxide-polypropylene oxide block copolymer; and (iii) one or more polyalkoxylated mono- or di-fatty acid esters or amides, the composition allowing reduced surfactant levels, while still having good rheological properties.

Claims

1. A composition that is a liquid hand soap or liquid body wash, comprising: a surfactant system comprising C.sub.8-18 alkyl-ether sulfate, cocamidopropyl betaine, and N-(2-hydroxyethyl) fatty acid amide; a polyethylene oxide-polypropylene oxide block copolymer; and one or more polyalkoxylated mono- or di-fatty acid esters or amides, wherein the C.sub.8-18 alkyl-ether sulfate is present in an amount of from about 5.5 to about 6.5 weight % based on a total weight of the composition, wherein the cocamidopropyl betaine is present in an amount of from about 1.5 to about 2.4 weight % based on a total weight of the composition, wherein the N-(2-hydroxyethyl) fatty acid amide is present in an amount of from about 0.2 to about 0.5 weight % based on a total weight of the composition, and wherein the composition has a zero-shear viscosity of from about 3,000 to about 4,000 mPas.

2. The composition of claim 1, wherein the C.sub.8-18 alkyl-ether sulfate comprises a compound of formula CH.sub.3(CH.sub.2).sub.mCH.sub.2(OCH.sub.2CH.sub.2).sub.nOSO.sub.3X, wherein m is 6-16; n is 1-6; and X is Na or K.

3. The composition of claim 1, wherein the N-(2-hydroxyethyl) fatty acid amide comprises cocamide monoethanolamine.

4. The composition of claim 1, wherein the polyethylene oxide-polypropylene oxide block copolymer has a formula (EO)x(PO)y(EO)z with x=8-14, z=8-14 and y=16-26.

5. The composition of claim 1, wherein the one or more polyalkoxylated mono- or di-fatty acid esters or amides are selected from the group consisting of (C.sub.2-C.sub.4)alkoxylated mono(C.sub.2-C.sub.3)alkanol isostearamide, polyethoxylated glyceryl fatty acid esters, polyethoxylated esters of fatty acids and saccharides, and combinations thereof.

6. The composition of claim 5, wherein the one or more polyalkoxylated mono- or di-fatty acid esters or amides are selected from the group consisting of PPG-2 hydroxyethyl coco/isostearamide, PEG-18 glyceryl oleate/cocoate, PEG-7 glyceryl cocoate, PEG-120 methyl glucose dioleate, and combinations thereof.

7. The composition of claim 6, wherein the one or more polyalkoxylated mono- or di-fatty acid esters or amides comprise PEG-120 methyl glucose dioleate.

8. The composition of claim 1, wherein the surfactant system comprises sodium lauryl ether sulfate, cocamidopropyl betaine and cocamide monoethanolamine.

9. The composition of claim 1, wherein: the surfactant system comprises sodium lauryl ether sulfate, cocamidopropyl betaine and cocamide monoethanolamine; the polyethylene oxide-polypropylene oxide block copolymer is (EO)x(PO)y(EO)z with x=8-14, z=8-14 and y=16-26; and the one or more polyalkoxylated mono- or di-fatty acid esters or amides are selected from the group consisting of PPG-2 hydroxyethyl coco/isostearamide, PEG-18 glyceryl oleate/cocoate, PEG-7 glyceryl cocoate, PEG-120 methyl glucose dioleate, and combinations thereof.

10. The composition of claim 1, further comprising a polyquaternium compound.

11. The composition of claim 1, further comprising at least 70 weight % water.

12. The composition of claim 1, wherein the total amount of surfactant is 5 to 9 weight %.

13. The composition of claim 1, wherein the amount of the polyethylene oxide-polypropylene oxide block copolymer is 0.01 to 0.15 weight %.

14. The composition of claim 1, wherein the composition does not include an alkylpolyglucoside surfactant.

15. The composition of claim 1, wherein the micelle relaxation time of the composition is less than 0.06 seconds.

16. The composition of claim 1, wherein the composition is a clear liquid hand soap.

Description

DETAILED DESCRIPTION

(1) The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

(2) As used throughout, ranges are used as shorthand for describing each and every value that is within the range. Any value within the range can be selected as the terminus of the range. In addition, all references cited herein are hereby incorporated by referenced in their entireties. In the event of a conflict in a definition in the present disclosure and that of a cited reference, the present disclosure controls.

(3) Unless otherwise specified, all percentages and amounts expressed herein and elsewhere in the specification should be understood to refer to percentages by weight. The amounts given are based on the active weight of the material.

(4) The term “soap” as used herein is given a broad meaning, and is intended to encompass agents to clean the hands and/or the body, including cosmetic or detergent substances as described in 21 C.F.R. 701.20, particularly products generally referred to as liquid hand soaps and body washes. Applicants recognize that, in some particular contexts, the term “soap” may be given a narrow definition as being a product primarily composed of alkali salts of fatty acids, but the term as used herein is not intended to be so limited. Thus a liquid hand soap, for example, need not contain any alkali salts of fatty acids.

(5) Unless otherwise specifically identified, the ingredients for use in the compositions of the present invention should be cosmetically acceptable ingredients. By “cosmetically acceptable” is meant suitable for use in a formulation for topical application to human skin. A cosmetically acceptable excipient, for example, is an excipient that is suitable for external application in the amounts and concentrations contemplated in the formulations of this invention, and includes for example excipients which are “Generally Recognized as Safe” (GRAS) by the United States Food and Drug Administration. Representative excipients include water, oils, both vegetable and mineral, soap bases, cream bases, lotion bases, ointment bases and the like, particularly aqueous detergent carriers, for example liquid hand soaps or body washes. In some embodiments, the cosmetically acceptable carrier contains topically acceptable quaternary ammonium compounds, which may serve as moisturizers or as antibacterial agents. They may additionally include buffers, preservatives, antioxidants, fragrances, emulsifiers, dyes and excipients known or used in the field of cosmetic formulation, including for example inert fillers, anti-irritants, tackifiers, excipients, fragrances, opacifiers, antioxidants, gelling agents, stabilizers, surfactant, emollients, coloring agents, preservatives, buffering agents, and other conventional components of topical formulations as are known in the art.

(6) The compositions and formulations as provided herein are described and claimed with reference to their ingredients, as is usual in the art. As would be evident to one skilled in the art, the ingredients may in some instances react with one another, on that the true composition of the final formulation may not correspond exactly to the ingredients listed. Thus, it should be understood that the invention extends to the product of the combination of the listed ingredients.

(7) As used throughout, ranges are used as shorthand for describing each and every value that is within the range. Any value within the range can be selected as the terminus of the range. In addition, all references cited herein are hereby incorporated by referenced in their entireties. In the event of a conflict in a definition in the present disclosure and that of a cited reference, the present disclosure controls.

(8) Polyethylene oxide-polypropylene oxide block copolymer (poloxamers) for use in Compositions 1, et seq. are nonionic triblock copolymers composed of a central hydrophobic chain of polyoxypropylene (poly(propylene oxide)) flanked by two hydrophilic chains of polyoxyethylene (poly(ethytene oxide)), for example compounds known under the trade names Synperonic®, Pluronic® and Kolliphor®. By convention, these copolymers may be named as “poloxamer” (or “P”) followed three digits, wherein the first two digits times 100 give the approximate molecular mass of the polyoxypropylene core in g/mol, and the last digit times 10 gives the approximate percentage polyoxyethylene content. Poloxamer 124 ((EO)x(PO)y(EO)z with x=8-14 (average 11), z=8-14 (average 11) and y=16-26 (average 21)) thus has a polyoxypropylene molecular mass of about 1200 g/mol and a polyoxyethylene content of about 40%. In certain embodiments, poloxamers for use in Compositions 1, et seq. are liquid at room temperature and have a polyoxypropylene molecular mass of about 800-1600 g/mol and a polyoxyethylene content of about 30-50. In some embodiments, the compositions comprise poloxamer 124, e.g., Pluronic® L-44, commercially available from BASF.

(9) Compositions 1, et seq. may in some embodiments additionally comprise skin conditioners or moisturizers, for example polyquaternium compounds. Polyquaternium is a term for polymers having quaternary ammonium centers in the polymer, useful in personal care products, e.g., as set forth in the International Nomenclature for Cosmetic Ingredients. Different polyquaterniums are distinguished by number, wherein the number corresponds to a particular polymer type. In some particular embodiments, Compositions 1, et seq. comprise Polyquaternium-7, which is a copolymer of acrylamide and diallyldimethylammonium chloride.

(10) Polyalkoxylated mono- or di-fatty acid esters or amides for use in Compositions 1, et seq. include a. (C.sub.2-C.sub.4)alkoxylated mono(C.sub.2-C.sub.3)alkanol fatty acid amides, e.g. as disclosed in U.S. Pat. No. 6,635,607, incorporated herein by reference, e.g. of formula R.sub.1—CO—NH—CH.sub.2—CH.sub.2—O—(CH.sub.2—CH(R.sub.2)—O).sub.n—H, wherein R.sub.1 is a C.sub.8-18 linear or branched hydrocarbon (for example wherein R.sub.1—CO— is an acyl from coconut oil fatty acids, isostearic acid, or mixtures thereof), R.sub.2 is H, CH.sub.3, CH.sub.2CH.sub.3, and n is 2 or 3; for example PPG-2 hydroxyethyl coco/isostearamide, (e.g., Promidium-2®, available from Croda); b. polyethoxylated glyceryl fatty acid esters, for example PEG-18 glyceryl oleate/cocoate (e.g., Antil 171, available from Evonik-Goldschmidt), and PEG-7 glyceryl cocoate; c. polyethoxylated esters of fatty acids and saccharides, e.g. PEG-120 methyl glucose dioleate (e.g. Glucamate® DOE-120, available from Lubrizol); and d. combinations of any of the foregoing.

(11) In some embodiments, Compositions 1, et seq. may also comprise suitable antioxidants; that is, substances known to inhibit oxidation. Antioxidants suitable for use in accordance with the present invention include, but are not limited to, butylated hydroxytoluene, ascorbic acid, sodium ascorbate, calcium ascorbate, ascorbic palmitate, butylated hydroxyanisole, 2,4,5-trihydroxybutyrophenone, 4-hydroxymethyl-2,6-di-fert-butylphenol, erythorbic acid, gum guaiac, propyl gallate, thiodipropionic acid, dilauryl thiodipropionate, tert-butylhydroquinone and tocopherots such as vitamin E, and the like, including pharmaceutically acceptable salts and esters of these compounds; e.g., butylated hydroxytoluene, butylated hydroxyanisole, propyl gallate, ascorbic acid, pharmaceutically acceptable salts or esters thereof, or mixtures thereof; for example butylated hydroxytoluene. When the topical formulations of the present invention contain at least one antioxidant, the total amount of antioxidant present is from about 0.001 to 0.5 wt %, 0.05 to 0.5 wt %, e.g. about 0.1%.

(12) Compositions 1, et seq. may also comprise suitable preservatives. Preservatives are compounds added to a formulation to act as an antimicrobial agent. Among preservatives known in the art as being effective and acceptable parenteral formulations are benzalkonium chloride, benzethonium, chlorohexidine, phenol, m-cresol, benzyl alcohol, methylparaben, propylparaben, chlorobutanol, o-cresol, p-cresol, chlorocresol, phenylmercuric nitrate, thimerosal, benzoic acid, sodium benzoate, sodium salicylate and various mixtures thereof. When the compositions contain at least one preservative, the total amount of preservative present is from about 0.01 to about 1 wt %, depending on the characteristics of the particular preservatives selected and the amount required for effective preservation in the particular formulation. In some embodiments, the compositions comprise sodium benzoate and sodium salicylate in a total amount of 0.1% to 1%.

(13) Compositions 1, et seq., may in some embodiments also comprise suitable chelating agents to form complexes with metal cations that do not cross a lipid bilayer. Examples of suitable chelating agents include ethylene diamine tetraacetic acid (EDTA), ethylene glycol-bis(beta-aminoethyl ether)-N,N,N′,N′-tetraacetic acid (EGTA) and 8-Amino-2-[(2-amino-5-methylphenoxy)methyl]-6-methoxyquinoline-N5N,N′,N′-tetraacetic acid, tetrapotassium salt (QUIN-2). When the compositions contain at least one chelating agent, the total amount of chelating agent present is 0.005 to 2 weight % by weight, depending on the particular chelator and formulation selected. For example, in some embodiments, the compositions contain 0.05 to 0.3 weight %. e.g., about 0.01 weight % of tetrasodium EDTA.

(14) Compositions 1, et seq. may also comprise suitable pH adjusting agents and/or buffers to adjust and maintain the pH of the formulation to a suitable range, e.g., pH 6-8 or approximately neutral pH, for example citric acid in amounts of 0.1 to 0.2 weight % to adjust the pH as required.

EXAMPLES

(15) Zero Shear Viscosity is measured as follows. Instrument: Stress controlled rheometer, TA Series AR2000. Geometry: 4 cm 2 degree acrylic cone Experiment: Frequency sweep @25° C. and 1% Strain from 0.1-100 rad/s Calculations are made using the data generated from the frequency sweep to determine relaxation time and shear viscosity.

Example 1

(16) Lowering the surfactant level while adjusting the salts to maintain viscosity is found to produce a product having significantly greater micelle relaxation times, e.g. greater than 0.1 sec, as seen in Table 1, and consequently, significantly greater stringiness, making the product messy and difficult to dispense. Different polymers are assessed for their effects on micelle relaxation time (t.sub.M) and viscosity.

(17) TABLE-US-00001 TABLE 1 Active Zero Surfactant Shear concentration Relaxation Viscosity Formula (wt %) Time (s) [mPas] Base Only (no 8.2 0.1369 5590 additives) 0.01% DOE 120 8.2 0.1665 7611  0.1% DOE 120 8.2 0.2688 18543 0.01% poloxamer 124 8.2 0.0617 2013 0.15% poloxamer 124 8.2 0.0189 254 0.05% Antil 8.2 0.1293 5984  0.1% Antil 8.2 0.1194 6137 0.05% Promidium 8.2 0.1636 7752  0.1% Promidium 8.2 0.1667 8158

(18) While none of the rheology modifiers individually are effective to address the problem of reducing stringiness while maintaining viscosity, particular combinations are found to provide good rheological properties, as seen below.

Example 2—Formulations

(19) Formulations are prepared using various levels and types of surfactants and rheology modifiers. Formulations having good rheological profiles and reduced surfactant (AI) levels are identified, e.g., as set forth on Table 2:

(20) TABLE-US-00002 TABLE 2 Commercial Prototype Prototype formulation 1a (active 2 (active Surfactant (active wt %) wt %) wt %) Sodium 7 5.9 5.6 laureth/pareth CAP betaine 2.6 1.8 2.5 CMEA — 0.37 0.37 Decyl Glucoside 1 — — Total surfactant 10.6 8.1 8.5

(21) Ingredients of these formulations are as set forth below.

(22) Prototype 1a:

(23) TABLE-US-00003 Wt (%) Active Ingredient Q.S. Di Water and minors (fragrance, color, preservatives) 5.9 SLES 1.8 CAP Betaine 0.1 Polyquaternium 7 0.73 Sodium Chloride 0.37 CMEA 0.04 PEG-18 glyceryl oleate/cocoate 0.02 Pluronic L-44 0.01 PEG-7 Glyceryl Cocoate
Prototype 1b:

(24) TABLE-US-00004 Wt % Active Ingredient Q.S. DI Water and minors (fragrance, color, preservatives) 5.8 SLES 1.8 CAP Betaine 0.1 Polyquaternium 7 1 Sodium Chloride 0.37 CMEA 0.05 Pluronic L-44 0.01 PEG-7 Glyceryl Cocoate
Prototype 2

(25) TABLE-US-00005 Wt % Active Ingredient Q.S. DI Water and minors (fragrance, color, preservatives) 5.5 SLES 2.5 CAP Betaine 0.1 Polyquaternium 7 1 Sodium Chloride 0.37 CMEA 0.05 Pluronic L-44 0.04 PEG-120 Dioleate 0.01 PEG-7 Glyceryl Cocoate

(26) The table below (Table 3) demonstrates the micelle relaxation times and shear viscosity for the two commercial liquid hand soap formulations and Prototypes 1a, 1b, and 2. As noted above, lowering the surfactant level while adjusting the salts to maintain viscosity led to a product having significantly greater micelle relation times, and consequently, significantly greater stringiness, making the product messy and difficult to dispense. In the particular formulations of this Example, however, while the weight percent of the surfactant is lower in the formulations of this Example, the relaxation times are lowered. Accordingly, the liquid hand soaps of this Example are an improvement over the market formulations, given that they can be produced with less surfactant, have a decreased micelle relaxation time and so are more cleanly dispensed, but still have a comparable shear viscosity to what is currently on the market.

(27) TABLE-US-00006 TABLE 3 Zero Relaxation Shear Time Viscosity Formula Type (s) (mPas) Market Formulation 1 0.0615 4797 Market Formulation 2 0.0603 4274 Prototype 1B 0.0488 3231 Prototype 1A 0.0512 3820 Prototype 2 0.0444 3583