Personal care compositions comprising taurate surfactant

Abstract

Disclosed are personal care compositions, e.g., skin care compositions, comprising at least one taurate surfactant, e.g., sodium methyl palmitoyl taurate, and at least one topically active compound, e.g., vitamin E acetate, as well as to methods of using these compositions.

Description

PERSONAL CARE COMPOSITIONS COMPRISING TAURATE SURFACTANTCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority from U.S. Provisional Application No.63 / 709,660, filed 21 October 2024, the contents of which are hereby incorporate herein by reference in its entirety.BACKGROUND

[0002] Rinse-off personal care products often seek to deliver active ingredients to the skin. In contrast to leave-on products, active delivery from rinse-off products like facial cleansers, liquid soaps, or body washes may be challenging due to the limited time period during which the formulation is in contact with the skin. Although skin care compositions are commonly used to deliver active ingredients, the effect may be transient or ineffective as the active ingredient may not be able to permeate various layers of the skin or maintain contact with the skin.

[0003] Several factors can impact the deposition of an active ingredient from a rinse-off product, including, for example, the choice of surfactant. A surfactant may contain a delicate blend of hydrophobic and hydrophilic components, where the balance between these components impacts the overall performance. Surfactants of a higher hydrophilic character typically generate denser foams, which are often desired of consumers. However, they can also be harsher on the skin. Surfactants of a higher hydrophobic character often generate a less dense foam, although these surfactants are typically gentler on the skin and may imparl a formula with a “creamy” appearance that is often desired by consumers.

[0004] Conventional personal care compositions primarily utilize anionic surfactants as a foaming agent. Sulfate -based surfactants are commonly used for personal care products such as shampoo, body wash, and face cleanser. The most common sulfate-based surfactants are sodium lauryl sulfate (SLS) and sodium lauryl ether sulfate (SLES). However, consumer studies and surveys have shown that there is a desire to use personal care compositions that do not contain any sulfate-based surfactants, as some consumers experience relatively greater sensitivity to these ingredients. Sulfates can cause varying levels of skin and eye irritation, which may get worse the longer the product is in contact with the skin. Sulfate-free compositions arc gaining more and more attraction among consumers, who associate sulfate-free products with more natural and less harsh materials.Among other benefits, sulfate-free bases offer a unique opportunity to re-evaluate active delivery, in particular active deposition.

[0005] Accordingly, there is a need for personal care compositions that can effectively deposit topically active compounds on the skin and may optionally be sulfate-free.BRIEF SUMMARY

[0006] In one aspect, the disclosure provides a personal care composition comprising at least one taurate surfactant and at least one topically active compound.

[0007] In some embodiments, the at least one taurate surfactant is selected from sodium methyl lauroyl taurate, sodium methyl cocoyl taurate, sodium methyl palmitoyl taurate, sodium methyl oleoyl taurate, and sodium methyl stearoyl taurate, preferably sodium methyl palmitoyl taurate. In certain embodiments, the at least one taurate surfactant is present in the personal care composition in an amount ranging from about 1% to about 20%, such as from about 2% to about 18%, about 4% to about 16%, about 6% to about 14%, about 8% to about 12%, or about 10%, by weight relative to a total weight of the personal care composition.

[0008] In some embodiments, the at least one topically active compound is selected from hydrophobic compounds, and in certain embodiments, the at least one topically active compound is a vitamin, such as a vitamin selected from vitamin C, vitamin D, vitamin E, vitamin K, and derivatives and combinations thereof. In certain embodiments of the disclosure, the vitamin is vitamin E or a derivative thereof, such as vitamin E acetate. In certain embodiments, the topically active compound is present in the personal care composition in an amount ranging from about 0.05% to about 1%, such as from about 0.1% to about 0.5%, or about 0.1%, by weight based on a total weight of the personal care composition.

[0009] In certain embodiments, the personal care composition disclosed herein further comprises at least one thickener, and in certain embodiments, the at least one thickener is a gum, such as a gum selected from xanthan gum, carrageenan gum, and a combination thereof. In certain embodiments, the personal care composition further comprises at least humectant, and in certain embodiments, the at least one humectant is selected from glycerin, sorbitol, and combinations thereof.

[0010] In certain embodiments of the disclosure, the personal care composition is free or substantially free of SLS and / or SLES.

[0011] In various embodiments, the personal care composition is a rinse-off composition, and in certain embodiments, the personal care composition a liquid soap, liquid hand soap, shower gel, body wash, shampoo, or hair conditioner, such as a liquid facial soap.

[0012] Also disclosed herein are methods of enhancing deposition of at least one topically active compound to skin of a subject, comprising applying the personal care composition according to any one of the preceding claims to the skin of the subject, wherein the method enhances an amount of the at least one topically active compound deposited as compared to a personal care composition that does not comprise at least one taurate surfactant. In certain embodiments of the methods disclosed herein, the method enhances deposition of the at least one topically active compound to the skin by at least about 0.1 pg / cm2, such as at least about 0.2 g / cm2, about 0.3 pg / cm2, about 0.4 pg / cm2, or at least about 0.5 pg / cm2, as compared to a personal care composition that does not comprise at least one taurate surfactant.

[0013] In another aspect, disclosed herein is a use of a personal care composition as disclosed herein for increasing the deposition of the at least one topically active compound on the skin of a subject when applying the composition to the skin.

[0014] Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating some typical aspects of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG. 1A is a bar graph showing the assay results for the first trial of the deposition study for vitamin E acetate in Compositions A-F, as described in Example 1.

[0016] FIG. IB is a bar graph showing the assay results for the second trial of the deposition study for vitamin E acetate in Compositions A-F, as described in Example 1.

[0017] FIG.2A is a bar graph showing the deposition efficiency for the first trial of the deposition study for vitamin E acetate in Compositions A-F, as described in Example 1.

[0018] FIG. 2B is a bar graph showing the deposition efficiency for the second trial of the deposition study for vitamin E acetate in Compositions A-F, as described in Example 1.

[0019] FIG.3 is a bar graph showing the maximum foam volume (mL), bubble count (mm2), and bubble area (pm2) for Compositions A-F, as described in Example 1.

[0020] FIG. 4A is a bar graph showing the assay results for the first trial of the deposition study for vitamin E acetate in Compositions G-L, as described in Example 2.

[0021] FIG.4B is a bar graph showing the assay results for the second trial of the deposition study for vitamin E acetate in Compositions G-L, as described in Example 2.

[0022] FIG. 5 is a bar graph showing the assay results for the deposition study for vitamin E acetate in Compositions K, L, and M, as described in Example 2.

[0023] FIG.6 is a graph showing the foam profile analysis of Compositions G-M by volume (mL), as described in Example 2.DETAILED DESCRIPTION

[0024] The following description of various typical aspects is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses.

[0025] 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 reference 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.

[0026] 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.

[0027] The present disclosure relates to personal care compositions that effectively deposit topically active compounds (e.g., a vitamin) on the skin.

[0028] As disclosed herein, it has been found that the use of an amino acid surfactant in a liquid rinse-off product may lead to an increase in the deposition of an active compound (e.g., a vitamin such as vitamin E acetate) as compared to the use of other surfactants like sodium lauryl sulfate (SLS) or sodium lauryl ether sulfate (SLES). While amino acid surfactants, such as for example sodium cocoyl glutamate, may be used to impart active deposition of an active compound to the skin, it was surprisingly discovered and is disclosed herein that, amongst various amino acid surfactants, taurate surfactants may lead to a dramatically increased deposition of an active compound when a composition comprising a taurate surfactant is applied to the skin. Tauratesurfactants may be a particularly advantageous choice of surfactant as they are sulfate-free and thus may be more appealing to consumers that traditional sulfate surfactants of SLS or SLES.

[0029] Additionally, as disclosed herein, certain taurate-based surfactants provided an unexpectedly high level of deposition of a topically active compound from a rinse-off formula as compared to other taurate-based surfactants. Namely, taurate surfactants having an increased carbon chain length, for example a carbon chain length ranging from C12 to Cis, e.g., Cu to Ci6 or Ci6, and / or fully saturated carbon chains, provided superior levels of active deposition on the skin. In certain embodiments, an exemplary taurate surfactant is sodium methyl palmitoyl taurate.

[0030] The present disclosure provides, in certain aspects, a personal care composition, e.g., skin care composition, comprising at least one taurate surfactant and at least one topically active compound. In certain embodiments, the at least one taurate surfactant comprises sodium methyl palmitoyl taurate, and in certain embodiments, at least one topically active compound comprises a vitamin, e.g., vitamin E.Taurate Surfactants

[0031] In certain embodiments, the at least one taurate surfactant of the present disclosure comprises a taurate surfactant in an amount of from about 1% to about 20%, by weight based on a total weight of the personal care composition. Taurate is a salt of taurine, which is a sulfur-containing amino acid having the formula C2H7NO3S. Taurine is also known as 2-aminoethanesulfonic acid, and is a naturally-occurring amino acid widely distributed throughout animal tissues.

[0032] In certain embodiments, the taurate surfactant is a C12-C18 taurate surfactant, such as a taurate surfactant chosen from salts of methyl lauroyl taurate, methyl cocoyl taurate, methyl palmitoyl taurate, methyl oleoyl taurate, and methyl stearoyl taurate. The salt may be sodium or potassium. For example, the at least one taurate surfactant may be chosen from sodium methyl lauroyl taurate, sodium methyl cocoyl taurate, sodium methyl palmitoyl taurate, sodium methyl oleoyl taurate, and sodium methyl stearoyl taurate. In certain exemplary embodiments, the taurate surfactant is a Ci6 taurate surfactant, and in certain embodiments, the taurate surfactant comprises a saturated hydrocarbon tail. In certain embodiments, the taurate surfactant is a salt of methyl palmitoyl taurate, and in certain embodiments, the taurate surfactant is sodium methyl palmitoyl taurate.

[0033] In some embodiments, the surfactant system of the present disclosure may comprise a cosurfactant. Additional surfactants, which may be zwitterionic or nonionic, and arc known for use in personal care compositions, may be used as a co- surfactant. In some embodiments, the cosurfactant may comprise an alkyl glucoside. Alkyl glucoside is a compound produced by combining a sugar such as glucose with a fatty alcohol. Alkyl refers to unbranched or branched carbon chain. In some embodiments, the alkyl group is unbranched. The alkyl group may be saturated or unsaturated. In some embodiments, the alkyl group is saturated.

[0034] Alkyl glucoside may be Cs-25 alkyl glucoside, e.g., Cs-18 alkyl glucoside, Cio-18 alkyl glucoside or Cio-16 alkyl glucoside. In some embodiments, the alkyl glucoside is selected from decyl glucoside, caprylyl / capryl glucoside, lauryl glucoside, coco-glucoside, octyl glucoside, cetearyl glucoside, cetyl glucoside, hexadecyl glucoside, arachidyl glucoside, and a combination thereof. In some embodiments, the alkyl glucoside is selected from decyl glucoside, caprylyl / capryl glucoside and a combination thereof. In some embodiments, the weight ratio of caprylyl / capryl glucoside to decyl glucoside present in the composition is 2 to 1 or 4 to 1, e.g., about 3 to 1.

[0035] In some embodiments, the alkyl glucoside is present in the personal care composition an amount ranging from about 1% to about 9%, such as from about 2% to about 8%, from about 2% to about 7%, from about 2% to about 6%, from about 2% to about 5%, from about 2% to about 4%, from about 2% to about 3%, from about 3% to about 8%, from about 3% to about 7%, from about 3% to about 6%, from about 3% to about 5%, from about 3% to about 4%, from about 4% to about 8%, from about 4% to about 7%, from about 4% to about 6%, from about 4% to about 5%, from about 5% to about 8%, from about 5% to about 7%, from about 5% to about 6%, from about 6% to about 8%, from about 6% to about 7%, or from about 7% to about 8%, by weight based on a total weight of the personal care composition.

[0036] In some embodiments, the co-surfactant may comprise a betaine zwitterionic surfactant, optionally together with an alkyl glucoside. The betaine zwitterionic surfactant may be a Cs-Ci6 aminopropyl betaine, e.g., cocamidopropyl betaine. In some embodiments, the co-surfactant may comprise a non-ionic block copolymer, optionally together with an alkyl glucoside. The non-ionic block copolymer may be a polypropylene oxide) / poly(ethylene oxide) copolymer. In some embodiments, the copolymer has a polyoxypropylene molecular mass of from 3000 to 5000 g / mol and a polyoxyethylene content of from 60 to 80 mol%. In some embodiments, the non-ionic blockcopolymer is a poloxamer. In some embodiments, the non-ionic block copolymer is selected from: Poloxamer 338, Poloxamer 407, Poloxamer, 237, Poloxamer, 217, Poloxamer 124, Poloxamer 184, Poloxamer 185, and a combination of two or more thereof. In some embodiments, the copolymer is Poloxamer 407. In some embodiments, the co-surfactant may comprise a betaine zwitterionic surfactant and a non-ionic block copolymer, optionally together with an alkyl glucoside.

[0037] The at least one taurate surfactant disclosed herein increases the deposition of at least one topically active compound on the skin when the taurate surfactant is used in personal care compositions, e.g., skin care compositions. For example, the at least one taurate surfactant may increase the deposition of the at least one active compound on the skin as compared to a personal care composition that does not contain at least one taurate surfactant. In certain embodiments, the at least one taurate surfactant is sodium methyl palmitoyl taurate, and the sodium methyl palmitoyl taurate increases the deposition of the at least one active compound on the skin as compared to a personal care composition that does not contain sodium methyl palmitoyl taurate, e.g., contains a different amino acid surfactant or a different taurate surfactant.

[0038] In certain aspects, the at least one taurate surfactant is present in the personal care composition in an amount ranging from about 1% to about 20%, by weight based on a total weight of the personal care composition. In certain embodiments, the at least one taurate surfactant is present in the personal care composition in an amount ranging from about 2% to about 18%, such as from about 2% to about 16%, about 2% to about 14%, about 2% to about 12%, about 2% to about 10%, about 4% to about 18%, about 4% to about 16%, about 4% to about 14%, about 4% to about 12%, about 4% to about 10%, about 6% to about 18%, about 6% to about 16%, about 6% to about 14%, about 6% to about 12%, about 6% to about 10%, about 8% to about 18%, about 8% to about 16%, about 8% to about 14%, about 8% to about 12%, about 8% to about 10%, or about 10%, by weight based on a total weight of the personal care composition.

[0039] In certain embodiments, the personal care composition does not contain any surfactant other than the at least one taurate surfactant, and in certain aspects, the personal care composition comprises at least one co- surfactant in addition to the at least one taurate surfactant. In certain embodiments, the at least one taurate surfactant comprises a fully saturated hydrocarbon tail.

[0040] As used herein, both sodium methyl lauroyl taurate and sodium methyl cocoyl taurate comprised C12 hydrocarbon chains. Sodium methyl cocoyl taurate, however, is generallyconsidered to comprise a mixture comprising a high percentage (e.g., about 40%) of Cn hydrocarbon chains and the remainder of hydrocarbon chains similar to the fatty acids found naturally occurring in coconut oil.Topically Active Compounds

[0041] In embodiments of the disclosure, the personal care composition comprises at least one topically active compound for deposition onto the skin. In certain embodiments, the at least one topically active compound is hydrophobic, and in certain embodiments, the at least one topically active compound is hydrophilic. In certain exemplary embodiments, the at least one active compound is a vitamin. In certain embodiments, the at least one active compound is a vitamin selected from vitamin C, vitamin D, vitamin E, vitamin K, derivatives thereof, and combinations thereof. In certain embodiments, the vitamin is vitamin E or a derivative thereof, such as vitamin E acetate or vitamin E succinate.

[0042] Topically active compounds may encompass a wide range of materials, including antibacterial agents, vitamins, medicaments, fragrance materials, antioxidants, antiperspirant actives, deodorant actives, and other skin-care ingredients. The personal care composition of the present disclosure comprises a vitamin. Illustrative vitamins may be or include, but are not limited to, vitamin C, vitamin D, vitamin E, vitamin K, and a combination thereof. In some embodiments, the composition comprises vitamin E, e.g., vitamin E acetate. In some embodiments, vitamin E may be present in an amount of from about 0.05% to about 1%, e.g., from about 0.05% to about 0.5%, from about 0.05% to about 0.3%, from about 0.05% to about 0.2%, from about 0.05% to about 0.15%, or about 0.1%, by weight based on a total weight of the personal care composition.

[0043] Vitamin E is a family of four isomers of tocopherols and four isomers of tocotrienols. All eight isomers of vitamin E have a 6-chromanol ring structure and a side chain. The four tocopherols include fully saturated side chains and include alpha-tocopherol, gamma-tocopherol, betatocopherol, and delta-tocopherol. The four tocotrienols include unsaturated side chains and include alpha-tocotrienol, gamma-tocotrienol, beta-tocotrienol, and delta- tocotrienol. As used herein, the term “vitamin E” may refer to any one or more of the eight isomers. For example, as used herein, vitamin E may be or include one or more of alpha-tocopherol, gamma-tocopherol, beta-tocopherol, delta-tocopherol, alpha-tocotrienol, gamma-tocotrienol, beta-tocotrienol, delta-tocotrienol, or any combination thereof. In at least one embodiment, the vitamin E includes at least one of the four tocopherols. In certain embodiments, the vitamin E includes gamma-tocopherol, and gamma-tocopherol may make up the major component of the vitamin E. For example, the vitamin E may include gamma-tocopherol in an amount relatively greater than any one or more of the other isomers of vitamin E. In at least one embodiment, the vitamin E includes only gamma-tocopherol or includes substantially only gamma-tocopherol. It should be appreciated that the vitamin E and / or the isomers thereof may be or include natural forms of vitamin E, synthetic forms of vitamin E, or combinations thereof. Any one or more of the isomers of vitamin E may be in the “d” form, the “1” form, or combinations thereof. In some embodiments, vitamin E is vitamin E acetate or vitamin E succinate. In some embodiments, vitamin E is vitamin E acetate.

[0044] Vitamin C may be ascorbic acid or derivatives thereof. Ascorbic acid exists as two enantiomers commonly denoted “1” (for “levo”) and “d” (for “dextro”). The “1” isomer is the one most often encountered. Ascorbic acid is also referred to as L(+)-ascorbic acid or 1-ascorbic acid. The ascorbic acid derivatives may be or include, but are not limited to, L-ascorbic acid, calcium ascorbate, calcium 1-ascorbate dihydrate, magnesium ascorbate, potassium ascorbate, magnesium L-ascorbyl phosphate (also referred to as: magnesium ascorbate phosphate or ascorbic acid phosphate magnesium salt), L-ascorbic acid 2-phosphate sesquimagnesium salt hydrate, (+) sodium L-ascorbate, dehydro-l-(+)-ascorbic acid dimer, sodium ascorbyl phosphate (also referred to as: ascorbic acid phosphate sodium salt, sodium l-ascorbyl phosphate, 2-phospho-L-ascorbic acid trisodium salt, L-ascorbic acid 2-phosphate trisodium salt or sodium L-ascorbyl-2-phosphate), ascorbic acid-2-glucoside, ascorbyl dipalmitate, ascorbyl methylsilanol pectinate, ascorbyl stearate, disodium ascorbyl sulfate, ascorbyl 6-palmitate, calcium ascorbyl phosphate, ascorbyl acetate, ascorbyl propionate, ascorbyl stearate, ascorbyl palmitate, ascorbyl dipalmitate, ascorbyl glucoside, ascorbic acid polypeptide, ethyl ascorbyl ether, ascorbyl ethyl silanol pectinate, or the like, or combinations thereof.

[0045] Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. The two major forms are vitamin Lh or ergocalciferol, and vitamin D3 or cholecalciferol. Vitamin D includes vitamin Di (mixture of molecular compounds of ergocalciferol with lumisterol), vitamin D2 (ergocalciferol), vitamin D3 (cholecalciferol), vitamin D4 (22-dihydroergocalciferol), and vitamin D5 (sitocalciferol).

[0046] Vitamin K is a group of compounds with a common chemical structure of 2-methyl-I,4-naphthoquinone. Vitamin K plays a role in blood clotting, bone metabolism, and regulating bloodcalcium levels. Vitamin K includes vitamin Ki (phylloquinone) and vitamin K2 (menaquinone). Vitamin K2 have unsaturated isoprenyl side chains and are designated as MK-4 through MK-13, based on the length of their side chain.

[0047] The at least one active compound may be present in the personal care composition in any amount effective to obtain the desired activity of the at least one active compound. In certain embodiments, the at least one active compound is present in the personal care composition in an amount ranging from about 0.05% to about 1%, such as from about 0.05% to about 0.5%, from about 0.05% to about 0.3%, from about 0.05% to about 0.2%, from about 0.05% to about 0.15%, or about 0.1%, by weight based on a total weight of the personal care composition.

[0048] In certain embodiments, the personal care composition disclosed herein is free or substantially free of a sulfate-based surfactant. For example, in certain embodiments, the personal care composition is free or substantially free of SLS, and in certain embodiments, the personal care composition is free or substantially free of SLES. In certain embodiments, the personal care composition is free or substantially free of SLS and SLES. In certain embodiments, the personal care composition is free or substantially free of any one of alkyl sulfate salts, e.g., C1-25 alkyl sulfate salts, and / or alkyl aryl sulfonate salts, e.g., C1-25 alkyl aryl sulfonate salts, e.g., alkyl benzene sulfonate salts, e.g., sodium dodecyl benzene sulfonate.

[0049] As used herein, “substantially free” of a material refers to a composition where the material is present in an amount of less than about 0.1 weight %, such as less than about 0.05 weight %, less than about 0.01 weight %, less than about 0.005 weight %, less than about 0.001 weight %, or less than about 0.0001 weight % based on a total weight of the composition. In certain embodiments, “substantially free” of a material indicates that the material is not present in any detectable amount in the composition.

[0050] According to certain embodiments disclosed herein, the personal care composition is a rinse-off composition. As used herein, the term “rinse-off” indicates that the composition is applied to the user’s skin and / or hair, and then after a certain period of time, subsequently rinsed from the user’s skin and / or hair, e.g., by using water to rinse the personal care composition off of the user. In certain embodiments, the personal care composition is a liquid soap, such as a liquid facial soap, a liquid hand soap, a shower gel, or body wash; a shampoo; or a hair conditioner.

[0051] Also disclosed herein are personal care composition according to any of the embodiments disclosed herein for use in increasing the deposition of an active compound (e.g., a vitamin) on theskin of a subject, wherein the personal care composition comprises at least one taurate surfactant and at least one active compound.

[0052] Many personal care products incorporate oil such as sunflower seed oil, which may provide more “creme like” appearance and / or other benefits. The addition of sunflower seed oil may cause a previously homogenous mixture to become an oil-in-water emulsion. In some embodiments, the personal care composition comprises an oil selected from sunflower seed oil, olive oil, shear butter, jojoba oil, almond oil, grape seed oil, rose hip seed oil, mink oil, castor oil, soybean oil, mineral oil, and a combination thereof.

[0053] In some embodiments, the personal care composition comprises a thickener. In some embodiments, the thickener comprises a gum, optionally selected from xanthan gum, carrageenan gum, and a combination thereof.

[0054] in some embodiments, the personal care composition comprises a humectant, optionally wherein the humectant is selected from glycerin, sorbitol, and a combination thereof.

[0055] In some embodiments, the personal care composition comprises water.

[0056] In some embodiments, the personal care composition comprises an acyl glutamate, at least one topically active compound, a humectant, an oil, a surfactant, co-surfactants, and a gum.

[0057] In some embodiments, the personal care composition further comprises an antiperspirant active, a deodorant active, a gelling agent, an antioxidant, a fragrance, or a combination thereof.

[0058] In some embodiments of the personal care composition disclosed herein, the personal care composition results in a deposition of the active compound (e.g., vitamin E or a derivative thereof) on the skin of the user after rinse-off of at least about 0.1 pg / cm2, such as from about 0.1 pg / cm2to about 2 pg / cm2, e.g., from 0.2 pg / cm2to 1 pg / cm2, or from 0. 5pg / cm2to 0.8 pg / cm2. The amount of deposition may be measured by any method known in the art. In certain embodiments, the amount of deposition of an active compound may be measured using the methods disclosed in the Examples reported herein.

[0059] The composition of the present disclosure may be any type of personal care composition. In certain embodiments, the composition is any composition that can be formulated into topical skin care formulations suitable for application to skin. Examples of such compositions include, but are not limited to, skin care compositions (e.g., facial skin care compositions), antiperspirants, deodorants, body washes, creams, shower gels, bar soaps, shampoo, hair conditioners, and cosmetics. In some embodiments, the composition is a rinse-off product (liquid soap, liquid handsoap, shower gel, body wash, shampoo, or hair conditioner, etc.). The personal care composition can comprise a single phase or can be a multi-phase system, for example a system comprising a polar phase and an oil phase, optionally in the form of a stable emulsion. The personal care composition can be liquid, semi-solid, or solid. The formulation can be provided in any suitable container such as an aerosol can, tube or container with a porous cap, roll-on container, bottle, container with an open end, etc.

[0060] Water may be present in the personal care compositions disclosed herein. Water employed in the preparation of commercial personal care compositions should be deionized and free of organic impurities. Water commonly makes up the balance of the compositions and includes about 10% to about 90%, or about 10% to about 80%, by weight based on a total weight of the personal care compositions. This amount of water includes the free water which is added plus that amount which is introduced with other materials such as glycerin, sorbitol, or any components of the disclosure.

[0061] In some embodiments the disclosure provides a sulfate-free personal care formulation comprising any combination of at least one taurate surfactant, humectant, antioxidant, pH adjuster, active compound, fragrance, thickener, oil, and water.

[0062] In certain embodiments, the personal care composition comprises at least one pH adjuster, such as at least two pH adjusters. The pH adjusters of the present disclosure comprise any known pH adjuster used in the art, including but not limited to lactic acid, sodium hydroxide, and citric acid. In certain embodiments, the personal care composition comprises lactic acid, and in certain embodiments, the personal care composition comprises citric acid. In certain embodiments, the personal care composition comprises lactic acid and citric acid.

[0063] In some embodiments the disclosure provides a personal care composition comprising an antibacterial agent. The antibacterial agent of the disclosure may, for example, be lactic acid and / or citric acid.

[0064] Optional ingredients that may be included in the personal care composition of the disclosure include solvents; water-soluble alcohols such as C2-8 alcohols including ethanol; glycols including propylene glycol, dipropylene glycol, tripropylene glycol and mixtures thereof; glycerides including mono-, di- and triglycerides; medium to long chain organic acids, alcohols and esters; surfactants including emulsifying and dispersing agents; amino acids including glycine;structurants including thickeners and gelling agents, for example polymers, silicates and silicon dioxide; emollients; fragrances; and colorants including dyes and pigments.

[0065] The personal care composition may optionally contain emollients in any desired amount to achieve a desired emollient effect. Emollients are known in the art and are used to impart a soothing effect on the skin. Non-volatile emollients are preferable. Classes of non-volatile emollients include non-silicone and silicone emollients. Non-volatile, non-silicone emollients include C12-15 alkyl benzoate. The non-volatile silicone material can be a polyethersiloxane, polyalkyarylsiloxane or polyethersiloxane copolymer. An illustrative non-volatile silicone material is phenyl trimethicone. Examples include, but are not limited to, PPG- 14 butyl ether, PPG-3 myristyl ether, secondary alcohol ethoxylates, stearyl alcohol, stearic acid and salts thereof, glyceryl monoricinoleate, isobutyl palmitate, glyceryl monostearate, isocetyl stearate, sulphated tallow, oleyl alcohol, propylene glycol, isopropyl laurate, mink oil, sorbitan stearate, cetyl alcohol, hydrogenated castor oil, stearyl stearate, hydrogenated soy glycerides, isopropyl isostearate, hexyl laurate, dimethyl brassylate, decyl oleate, diisopropyl adipate, n-dibutyl sebacate, diisopropyl sebacate, 2-ethyl hexyl palmitate, isononyl isononanoate, isodecyl isononanoate, isotridecyl isononanoate, 2-ethyl hexyl palmitate, 2-ethyl hexyl stearate, Di-(2-ethyl hexyl)adipate), Dimethyl hexyl) succinate, isopropyl myristate, isopropyl palmitate, isopropyl stearate, octacosanol, butyl stearate, glyceryl monostearate, polyethylene glycols, oleic acid, triethylene glycol, lanolin, castor oil, sunflower seed oil, acetylated lanolin alcohols, acetylated lanolin, petrolatum, isopropyl ester of lanolin, fatty acids, mineral oils, butyl myristate, isostearic acid, palmitic acid, PEG-23 oleyl ether, olelyl oleate, isopropyl linoleate, cetyl lactate, lauryl lactate, myristyl lactate, quatemised hydroxy alkyl, aminogluconate, vegetable oils, isodecyl oleate, isostearyl neopentanoate, myristyl myristate, oleyl ethoxy myristate, diglycol stearate, ethylene glycol monostearate, myristyl stearate, isopropyl lanolate, paraffin waxes, glycyrrhizic acid, hydrocyethyl stearate amide. In some embodiments, the personal care composition comprises an oil selected from sunflower seed oil, olive oil, shear butter, jojoba oil, almond oil, grape seed oil, rose hip seed oil, mink oil, castor oil, soybean oil, mineral oil, and a combination thereof.

[0066] The personal care composition disclosed herein may include one or more humectants. Humectants can reduce evaporation and also contribute towards preservation by lowering water activity. Illustrative humectants may be or include, but are not limited to, glycerin, propylene glycol, polyethylene glycol, sorbitol, xylitol, or the like, or any mixture or combination thereof. Insome embodiments, the humectant is selected from glycerin, sorbitol and a combination thereof. In certain embodiments the humectant is glycerin.

[0067] The compositions disclosed herein may include thickeners. Illustrative thickeners may be or include, but are not limited to, colloidal silica, fumed silica, a cross-linked polyvinylpyrrolidone (PVP) polymer, cross-linked polyvinylpyrrolidone (PVP), or the like, or mixtures or combinations thereof. In some embodiments, the thickening system includes a cross-linked polyvinylpyrrolidone (PVP) polymer. Illustrative thickeners may also be or include, but are not limited to, carbomers (e.g., carboxy vinyl polymers), carrageenans (e.g., Irish moss, carrageenan gum, iota-carrageenan, etc.), high molecular weight polyethylene glycols, cellulosic polymers, hydroxyethylcellulose, carboxymethylcellulose, and salts thereof (e.g., CMC sodium), natural gums (e.g., karaya, xanthan gum, gum arabic, and tragacanth), colloidal magnesium aluminum silicate, or the like, or mixtures or combinations thereof. In some embodiments, the thickener comprises or is a gum, optionally selected from xanthan gum, carrageenan, and a combination thereof.

[0068] The personal care composition may comprise antiperspirant actives. The additional active antiperspirant ingredient may be selected from aluminum salts, zirconium salts and zinc salts. In some embodiment, the personal care composition may comprise an aluminum containing antiperspirant active. Any of the known aluminum containing antiperspirant active materials can be utilized in the composition. Aluminum containing antiperspirant actives include, but are not limited to, aluminum chlorohydrate, aluminum chloride, aluminum chlorohydrex polyethylene glycol, aluminum chlorohydrex propylene glycol, aluminum dichlorohydrate, aluminum dichlorohydrex polyethylene glycol, aluminum dichlorohydrex propylene glycol, aluminum sesquichlorohydrate, aluminum, sesquichlorohydrate polyethylene glycol, and aluminum sesquichlorohydrate propylene glycol.

[0069] The personal care composition may include any known deodorant active. Examples of deodorant actives include, but are not limited to, antimicrobial actives, alcohols, 2,4,4'-trichloro-2'-hydroxy diphenyl ether (Triclosan), benzethonium chloride, polyhexamethylene biguanides, triethylcitrate, 2-amino-2-methyl-l-propanol (AMP), cetyl-trimethylammonium bromide, cetyl pyridinium chloride, farnesol (3,7, 1 1-trimethyl -2,6,10- dodecatrien-l-ol), N-(4-chlorophenyl)-N'-(3,4-dichlorophenyl)urea (Triclocarban), silver halides, octoxyglycerin (Sensiva™ SC 50) and various zinc salts (for example, zinc ricinoleate), bactericides, and / or bacteriostats. The deodorant active can be included in the composition in an amount of 0 to about 5%, or from about 0.01% toabout 1 % by weight, based on the total weight of the composition. Triclosan can be included in an amount of about 0.05% to about 0.5% by weight, of the total weight of the composition.

[0070] Gelling agents may be included in the personal care composition disclosed herein. Examples of gelling agents include, but are not limited to, waxes, esters of fatty acid and fatty alcohol, triglycerides, partially or fully hydrogenated soybean oil, partially or fully hydrogenated castor oil, other partial or fully hydrogenated plant oils, stearyl alcohol, or other cosmetically acceptable materials, which are solid or semi-solid at room temperature and provide a consistency suitable for application to the skin.

[0071] Antioxidants may be added to the personal care composition, for example to act as ingredient protectants and for maintenance of long-term stability of the composition. Examples of antioxidants include, but are not limited to citric acid, butylated hydroxytoluene, and pentaerythrityl tetra-di-t-butyl hydroxyhydrocinnamate.

[0072] The personal care compositions disclosed herein may also contain polymeric materials for thickening, such as polyamides, cellulose derivatives (e.g., hydroxypropylcellulose, hydroxypropyl methyl cellulose, etc.) and natural or synthetic gums, such as polyglycerides including agar, agarose, pectin, or guars or mixtures or combinations thereof. One class of materials worthy of attention for thickening a water-immiscible phase comprises derivatives of hydrolysed starch or other polysaccharides, including in particular esterified dextrins, such as dextrin palmitate. A further class of polymers that is particularly directed to structuring an oil phase containing a silicone oil comprises poly siloxane elastomers. Suspending agents such as silicas or clays such as bentonite, montmorillonite or hectorite, including those available under the trademark BENTONE® can also be employed to thicken liquid compositions according to the disclosure. The personal care composition can be thickened with non-polymeric organic gellants, including selected dibenzylidene alditols (e.g., dibenzylidene sorbitol).

[0073] Fragrance may be included in the personal care composition disclosed herein. Any fragrance suitable for personal care use may be incorporated into the personal care composition of the disclosure. Fragrances tend to be relatively volatile aromatic compounds that are capable of entering the gas phase at skin surface temperature.

[0074] The personal care compositions of the disclosure may be manufactured using methods known in the art. Typically, the ingredients are combined and optionally heated where components need to be melted. The components are mixed. In certain embodiments, volatile materials such asfragrant materials are incorporated in the composition in the latter stages of a mixing cycle in order to avoid volatilization thereof. After mixing, the composition may be poured directly into the dispensers and the container capped to preserve the product until use.

[0075] In another aspect, the disclosure provides a method of depositing a topically active compound on the skin, comprising applying an effective amount of any of the personal care compositions disclosed herein to the skin. In certain embodiments, the method further comprises rinsing the personal care composition off of the skin, e.g., with water, after application. In certain embodiments, the personal care composition may be rinsed off immediately after application, and in certain embodiments, the personal care composition may be rinsed off at least about 5 seconds after application, such as at least about 10 seconds, at least about 15 seconds, at least about 20 seconds, at least about 25 seconds, at least about 30 seconds, at least about 35 seconds, at least about 40 seconds, at least about 45 seconds, at least about 50 seconds, at least about 55 seconds, or at least about 60 seconds, such as from about 5 seconds to about 60 seconds, about 5 seconds to about 45 seconds, or about 5 seconds to about 30 seconds after application, or any time period there in between.

[0076] In another aspect, the disclosure provides the use of at least one taurate surfactant, e.g., sodium methyl palmitoyl taurate, in a personal care composition comprising at least one topically active compound, e.g., at least one vitamin, for example vitamin E, for increasing the deposition of the at least one topically active compound on the skin when applying the composition to the skin.EXAMPLES

[0077] To evaluate vitamin E deposition on the skin using rinse-off formulations, vitamin E acetate was incorporated into various formulations after the formulation were prepared as described herein.Example 1 - Amino acid surfactants

[0078] Six sulfate-free personal care formulations comprising various amino acid surfactants were prepared as shown below in Table 1. Each prototype composition was formulated to produce a final concentration of about 10% active amino acid surfactant. Accordingly, because certain surfactants were not in neat form (i.e., sodium cocoyl alaninate, sodium lauroyl sarcosinate, sodium methyl cocoyl taurate, and sodium cocoyl isethionate), a higher percentage of thosesurfactant solutions was added in order to arrive at a final surfactant concentration of 10% for each composition.

[0079] Table 1 - Amino acid surfactant prototype compositionsCompositionIngredient A B c D E F Glycerin; 50% citric acid / 7.60% 7.60% 7.60% 7.60% 7.60% 7.60% 80% lactic acidXanthan gum; carrageenan1.00% 1.00% 1.00% 1.00% 1.00% 1.00% gumVitamin E acetate 0.10% 0.10% 0.10% 0.10% 0.10% 0.10% Fragrance 0.40% 0.40% 0.40% 0.40% 0.40% 0.40% Sodium cocoyl alaninate 33.33%* — -- -- -- — Sodium cocoyl glutamate -- 10.00% -- -- -- — Sodium lauroyl sarcosinate — — 10.53%* — — — Sodium methyl cocoyl— — — 10.53%* — — taurateSodium cocoyl glycinate -- -- -- -- 10.00% — Sodium cocoyl isethionate -- -- -- -- -- 12.50%* DI water QS QS QS QS QS QSTotal: 100% 100% 100% 100% 100% 100% * More than 10% surfactant solution added because solution was not 100% concentration; final amount of surfactant in each of Compositions A-F was 10%.

[0080] To prepare the compositions, deionized water was added to a suitable vessel and heated to 40 °C. Xanthan gum and carrageenan gum were dispersed in glycerin, and the dispersed mixture was added to the deionized water at 40 °C under continuous stirring until a homogenous mixture was achieved. Surfactant was added under continuous mixing. Once homogenous, the mixture was cooled down to 30 °C. Once cooled to 30 °C, citric acid and lactic acid premix were added, followed by vitamin E acetate and fragrance.

[0081] The vitamin E acetate deposition test was performed as follows: deposition studies were conducted on porcine back skin explants. Eight replicates of porcine back skin (Animal Technologies) were used to analyze the samples across two trials (four replicates per trial). The procedure for the rinse-off studies involved using 2-inch by 2-inch pieces of porcine back skin with subcutaneous fat removed. The rinse-off procedure entailed using warm water at a flow rate of 6 L / min and temperature of 100 °F. The skin was first wetted for five seconds, and then 50 |1L of a prototype composition was rubbed on the skin for 10 seconds. After 90 seconds of rest, theskin was rinsed with water for 15 seconds. After air drying for 5 minutes, a glass cup with a diameter of 3 cm was applied to the skin’s surface, and ethanol was applied within the cup. The skin was then rubbed for 30 seconds with a glass rod. The ethanol solution was pipetted into labeled scintillation vials. This procedure was repeated twice for a total of 6 mL of extracted ethanol. The scintillation vials were left to air dry before being re-solubilized in 1 mL of methanol and filtered into an HPLC vial for vitamin E acetate quantification. The entire experiment was conducted twice to ensure reproducibility of the observed results.

[0082] As shown in FIGS. 1A and IB, of the six amino acid surfactants tested, all delivered some quantifiable level of active to the skin, with sodium methyl cocoyl taurate providing superior deposition of the vitamin E acetate in both the first trial (FIG. 1A) and the second trial (FIG. IB). As shown in FIG 2A, in the first trial, sodium methyl cocoyl taurate provided a 43.91% deposition efficiency of the vitamin E acetate, while the next best surfactant, sodium cocoyl glycinate, provided a deposition efficiency of 9.58%. Sodium cocoyl glutamate, sodium cocoyl sarcosinate, sodium cocoyl alaninate, and sodium cocoyl isethionate provided 4.14%, 3.31%, 3.97%, and 3.68% deposition efficiency, respectively. As shown in FIG. 2B, the results of the second trial were consistent, wherein sodium methyl cocoyl taurate provided a 65.66% deposition efficiency of the vitamin E acetate, while the next best surfactant, sodium cocoyl glycinate, provided a deposition efficiency of 11.22%. In the second trial, sodium cocoyl glutamate, sodium cocoyl sarcosinate, sodium cocoyl alaninate, and sodium cocoyl isethionate provided 5.20%, 6.01%, 2.39%, and 4.31% deposition efficiency, respectively.

[0083] Dynamic Foam Analyzer (DFA) methodology: The DFA sample preparation process involved the preparation of diluted samples (5 wt%) for each of the six Compositions A-F. 50 mL of the diluted samples were delivered to the DFA column, and oscillatory stirring was commenced at 5000 rpm for a total of six times. During this time, the camera was set right below the air / foam interface for data collection on the foam profiles of each sample. After stirring stopped, the foam remained unagitated for 300 seconds. Finally, raw data values were obtained from the DFA software report and graphed to reveal foam profiles for each sample.

[0084] The DFA results are shown in FIG. 3. The DFA results demonstrate the unique foam characteristics of the Compositions A-F. The formulation comprising sodium methyl cocoyl taurate (Composition D) showed a sufficient foam volume. However, the data suggest that Composition D has lower foam stability when compared to the other samples, which is indicatedby the lowest bubble counts and highest bubble area (size) that were measured 5 minutes postagitation of the compositions. Composition D appeared to have the largest size bubble profile after sitting for 5 minutes. While not wishing to be bound by theory, it is possible that the bubble size plays a role in the unique deposition profile achieved.Example 2 - Taurate surfactants

[0085] The present example investigates a range of taurate surfactants in terms of active deposition. Because the hydrophilic “head group” was kept constant as taurate, the hydrophobic “tail” was varied by either varying the overall carbon length and / or the degree of unsaturation. In addition to evaluating these variables via deposition testing, they were also evaluated via their ability to generate foam in a rinse off formula.

[0086] Formulations were prepared as shown below in Table 2. The formulations were prepared comprising water and glycerin, thickened with xanthan gum and carrageenan gum. To this mixture, the surfactant of interested was added in an amount of about 10%, and then lactic acid and citric acid were added to modify the pH and provide a mild preservative effect. Lastly, vitamin E acetate was added as an active ingredient at a level of about 0.1%.

[0087] In total, seven different surfactants were evaluated as follows: sodium lauryl sulfate (SLS), sodium C14-16 olefin sulfonate, sodium methyl lauroyl taurate, sodium methyl cocoyl taurate, sodium methyl palmitoyl taurate, sodium methyl oleoyl taurate, and sodium methyl stearoyl taurate. SLS was chosen as a “negative control”; due to its highly hydrophilic nature it was theorized that formulas with this surfactant would provide low levels of active deposition. Sodium C14-16 olefin sulfonate is very similar in structure to SLS. However, instead of a sulfate head group, it has a sulfonate head group, similar’ to a taurate based surfactant. Therefore, it was included in the study to see if simply changing the head group from a sulfate to a sulfonate would cause major differences in active deposition. The five other surfactants tested all had a taurate head group, with carbon tails varying in either chain length or degree of saturation.

[0088] Compositions were prepared using the backbone formulation shown below in Table 2. The results of the deposition study are shown in Table 2 and illustrated in EIG. 4.

[0089] Table 2 - Taurate Surfactant Formula Backbone and Deposition Results CompositionsIngredientG H I J K L MDemineralized water QS QS QS QS QS QS QSGlycerin; 50% lactic8.00% 8.00% 8.00% 8.00% 8.00% 8.00% 8.00% acid / 50% citric acidXanthan gum;1.00% 1.00% 1.00% 1.00% 1.00% 1.00% 1.00% carrageenan gumSLS 10.00% -- -- — -- -- — Sodium C14-16— 10.00% — — — — — olefin sulfonateSodium methyl— — 10.00% — — — — lauroyl taurateSodium methyl— — — 10.00% — — — cocoyl taurateSodium methyl— — — — 10.00% — — palmitoyl taurateSodium methyl— — — — — 10.00% — oleoyl taurateSodium methyl— — — — — — 10.00% stearoyl taurateVitamin E acetate 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% 0.1% Total: 100% 100% 100% 100% 100% 100% 100% Vitamin E Acetate0.09 + 0.12 + 0.15 + 0.33 + 0.64 + 0.10 + deposition [pg / cm2] — 0.02 0.01 0.04 0.28 0.11 0.02(Trial 1)Vitamin E Acetate0.08 + 0.16 + 0.39 + 0.26 + 0.69 + 0.10 + deposition [pg / cm2] — 0.01 0.02 0.23 0.06 0.15 0.01(Trial 2)

[0090] The p-valucs calculated for the deposition studies for each composition arc shown below in Table 3 (Trial 1) and Table 4 (Trial 2).

[0091] Table 3 - P-values for Taurate Surfactant Deposition Data Study, Trial 1I K L H J(Na (Na (Na (Na (Na Cu-16Composition G (SLS) methyl methyl methyl methyl olefinlauroyl cocoyl palmitoyl oleoyl sulfonate)taurate) taurate) taurate) taurate) G (SLS) -- 0.0109 -- 0.1335 5.05E-05 -- H (NaC14-16— — — 0.1914 7.00E-05 — olefin sulfonate)I (Na methyl0.0290 0.2090 — 0.2655 0.0002 0.0618 lauroyl taurate)J (Na methyl— — — — — — cocoyl taurate)K (Na methyl— — — 0.0844 — —palmitoyl taurate)L (Na methyl0.4479 0.0789 — 0.1503 5.92E-05 —oleoyl taurate)

[0092] Table 4 - P-values for Taurate Surfactant Deposition Data Study, Trial 2I J K LH(Na (Na (Na (Na (Na CM-16Composition G (SLS) methyl methyl methyl methyl olefinlauroyl cocoyl palmitoyl oleoyl sulfonate)taurate) taurate) taurate) taurate) G (SLS) -- H (NaC14-16— — — 0.0203 0.0005 — olefin sulfonate)I (Na methyl0.0323 0.0941 — 0.3270 0.0676 0.0449 lauroyl taurate)J (Na methyl— — — — — — cocoyl taurate)K (Na methyl— — — 0.0020 — — palmitoyl taurate)L (Na methyl0.0011 0.0034 — 0.0018 0.0002 —oleoyl taurate)

[0093] All samples were analyzed on either four or six different replicates of porcine back skin, depending on the study. The procedure for the rinse-off studies was as follows: all deposition studies were conducted using 2-inch by 2-inch pieces of porcine back skin (Animal Technologies) with the subcutaneous fat removed. For the rinse-off procedure, warm water (100 °F) at a flow rate of 6 L / min was used. First, the skin was wetted for five seconds. Then, 50 .L of the appropriate product was added to the skin and rubbed on for 10 seconds. The skin was then allowed to rest for 90 seconds and then rinsed off with water for 15 seconds. After letting the skin air dry for 5 minutes, a glass cup (3 cm diameter) was applied to the surface of the skin. 3 mL of ethanol was applied within the cup, rubbed for 30 seconds with a glass rod, and then extracted into a labeled scintillation vial. This was repeated once more, for a total of 6 mL of extracted ethanol. The samples were left to air dry. Afterwards, samples were re-solubilized in 5 mL of methanol and filtered into an HPLC vial. The samples were then run on the HPLC for vitamin E acetate quantification.

[0094] The deposition testing of Compositions G-L (all surfactants except sodium methyl stearoyl taurate) are shown in FIGs. 4A-B. As shown in FIGs. 4A-B, in both instances the best performing surfactant for active deposition was sodium methyl palmitoyl taurate, and the worst performingsurfactant for active deposition was SLS, confirming its choice as an appropriate negative control. Additionally, in both cases sodium C14-I6 olefin sulfonate provided significantly higher levels of active deposition compared to SLS. This indicates that switching from a sulfate to sulfonate head group decreases the hydrophilic character of the surfactant, leading to higher active deposition. However, in general, sodium C14-I6 olefin sulfonate did not lead to as high of active deposition as the surfactants sodium methyl lauroyl taurate or sodium methyl cocoyl taurate, both of which have a carbon chain length of 12 on average. This indicates that while simply switching from a sulfate to a sulfonate head group does increase active deposition, it does not fully explain the enhanced deposition observed with many taurate based surfactants.

[0095] In general, sodium methyl lauroyl taurate and sodium methyl cocoyl taurate both resulted in intermediate levels of deposition that were not as high as sodium methyl palmitoyl taurate but not as low SLS. While not wishing to be bound by theory, these results, combined with the high deposition afforded by sodium methyl palmitoyl taurate, suggest that increasing the carbon chain length lead to higher levels of active deposition. This trend, however, was contradicted by the results demonstrated with sodium methyl oleoyl taurate. Sodium methyl oleoyl taurate has a carbon chain of 18 and yet resulted in deposition levels barely higher than that of SLS. It is hypothesized that this unusual behavior may be due to the single degree of unsaturation present in sodium methyl oleoyl taurate. This lone double bond (present in a cis configuration) may hinder the packing ability of the sodium methyl oleoyl taurate, effectively negating any benefits afforded by the long carbon chain. As evidence, the formula with sodium methyl palmitoyl taurate had an opaque, white, “creamy” appearance while the formula with sodium methyl oleoyl taurate had a more translucent appearance, indicative of smaller, more poorly packed micelles that would lead to a lower level of deposition of the hydrophobic active vitamin E acetate.

[0096] Next, a composition was prepared with sodium methyl stearoyl taurate (Composition M). Like sodium methyl oleoyl taurate, sodium methyl stearoyl taurate has an 18 carbon hydrophobic tail; however, it is also fully saturated. Therefore, Composition M should 1) provide a higher level of E acetate deposition than the formula containing sodium methyl oleoyl taurate (Composition L), due to the lack of any double bond, and 2) provide a higher level of vitamin E acetate deposition than the formula containing sodium methyl palmitoyl taurate (Composition K), as its carbon chain is two carbons longer.

[0097] The results of this deposition study are seen in FIG. 5 and in Table 5 below.

[0098] Table 5 - Taurate Surfactant Deposition Results for Compositions K, L, and M CompositionsK L MVitamin E Acetate0.51 + 0.18 0.09 + 0.02 0.33 + 0.13deposition [pg / cm2]Comp. K p-value — 0.0002 -- Comp. L p-value — — --Comp. M p-value 0.0786 0.0011 --

[0099] The formula with sodium methyl stearoyl taurate (Composition M) did in fact have significantly higher levels of vitamin E acetate deposition than the formula containing sodium methyl oleoyl taurate (Composition L). However, surprisingly Composition M also had a significantly lower level of vitamin E acetate deposition than the formula with sodium methyl palmitoyl taurate (Composition K). This suggests that for the taurate surfactants, lengthening the carbon chain length may increase the deposition of vitamin E acetate, but optimizes and maximizes at a 16 carbon length.

[0100] When preparing the formula with sodium methyl stearoyl taurate, it was observed that the formula had to be heated to dissolve the surfactant, a step not needed for the other surfactants (including sodium methyl palmitoyl taurate). While not wishing to be bound by theory, this indicates that the highly hydrophobic 18 carbon tail of sodium methyl stearoyl taurate may limit its ability to dissolve and self-assemble properly, which may ultimately hinder its ability to deposit a hydrophobic active compound like vitamin E acetate, especially compared to a surfactant like sodium methyl palmitoyl taurate, which can more easily be dissolved in the water base.

[0101] Dynamic Foaming Analysis'. Foaming behavior of Compositions G-M described above was studied using Dynamic Foaming Analyzer (DFA from Kruss). The samples were diluted to 5% by weight. 50 mL of the diluted solutions was delivered to a DFA cylinder. To generate foam, the solutions were stirred using a propeller attached to the DFA for 5 seconds at 5000 rpm in an oscillatory manner, i.e., for 2 seconds to one direction, for another 2 seconds to another direction, and for the rest 1 second to one direction. Subsequently, stirring was paused for 3 seconds, during which foam volume was measured. The sequence of 5 seconds of stirring followed by a 3 second pause was repeated 6 times. After the foam generation sequence was complete, the foam was left undisturbed for another 300 seconds to study foam decay behavior.

[0102] The foamability of the samples was largely dependent on the surfactants’ head group and their carbon chain length. See FIG. 6. Sodium lauryl sulfate and sodium olefin sulfonate (Compositions G and H) displayed higher foamability compared to taurate-based surfactants with similar carbon chain lengths; for example, when comparing sodium lauroyl taurate and sodium cocoyl taurate with sodium palmitoyl taurate. Among the taurate samples, the effect of varying chain lengths from C12 to Cis on foaming was observed. It was found that the foam volume increased monotonically with decreasing chain length, as shown in FIG. 6. While not wishing to be bound by theory, it is possible that this is because surfactants with shorter chains can rearrange more easily at the water-air interface. Another contributing factor is solubility. Sodium methyl stearoyl taurate does not dissolve in water well, which may have led to very low foamability for Composition M.

[0103] In summary, sodium methyl palmitoyl taurate was shown to provide the highest level of active deposition, which was attributed to its long (16 carbon) and unsaturated hydrophobic chain. Sodium methyl stearoyl taurate, with an even longer 18 carbon hydrophobic tail, had somewhat depressed deposition, while sodium methyl oleoyl taurate, which also has an 18 carbon tail plus a degree of unsaturation, had very low deposition of vitamin E acetate. This indicates that the 16 carbon, unsaturated tail of sodium methyl palmitoyl taurate provides an enhanced level of vitamin E acetate deposition amongst taurate-based surfactants. Additionally, dynamic foaming analysis indicated that while the sodium methyl palmitoyl taurate did not generate as large as a foam as shorter chain surfactants like SLS, it did generate a more voluminous foam when compared to longer chain sodium methyl oleoyl taurate or sodium methyl stearoyl taurate, giving a strong balance of both deposition and foaming properties.

[0104] The present disclosure has been described with reference to exemplary embodiments. Although a limited number of embodiments have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the preceding detailed description. It is intended that the present disclosure be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

CLAIMSWhat is claimed is:

1. A personal care composition comprising at least one taurate surfactant and at least one topically active compound.

2. The personal care composition according to claim 1, wherein the at least one taurate surfactant is selected from sodium methyl lauroyl taurate, sodium methyl cocoyl taurate, sodium methyl palmitoyl taurate, sodium methyl oleoyl taurate, and sodium methyl stearoyl taurate.

3. The personal care composition according to claim 1 or claim 2, wherein the at least one taurate surfactant is sodium methyl palmitoyl taurate.

4. The personal care composition according to any one of the preceding claims, wherein the at least one taurate surfactant is present in an amount ranging from about 1% to about 20%, such as from about 2% to about 18%, about 4% to about 16%, about 6% to about 14%, about 8% to about 12%, or about 10%, by weight relative to a total weight of the personal care composition.

5. The personal care composition of any one of the preceding claims, wherein the at least one topically active compound is selected from hydrophobic compounds.

6. The personal care composition according to any one of the preceding claims, wherein the at least one topically active compound is a vitamin.

7. The personal care composition according to claim 6, wherein the vitamin is selected from vitamin C, vitamin D, vitamin E, vitamin K, and derivatives and combinations thereof.

8. The personal care composition of claim 7, wherein the vitamin is vitamin E or a derivative thereof.

9. The personal care composition of claim 7 or claim 8, wherein the vitamin is vitamin E acetate.

10. The personal care composition according to any one of the preceding claims, wherein the topically active compound is present in an amount ranging from about 0.05% to about 1%, such as from about 0.1% to about 0.5%, or about 0.1%, by weight based on a total weight of the personal care composition.

11. The personal care composition of any one of the preceding claims, further comprising at least one thickener.

12. The personal care composition of claim 11, wherein the at least one thickener comprises a gum.

13. The personal care composition of claim 12, wherein the gum is selected from xanthan gum, carrageenan gum, and a combination thereof.

14. The personal care composition of any one of the preceding claims, further comprising at least one humectant selected from glycerin and sorbitol.

15. The personal care composition of any one of the preceding claims, wherein the personal care composition is free or substantially free of sodium lauryl sulfate (SLS) and / or sodium lauryl ether sulfate (SLES).

16. The personal care composition of any one of the preceding claims, wherein the personal care composition is a rinse-off composition.

17. The personal care composition of any one of the preceding claims, wherein the personal care composition is a liquid soap, liquid hand soap, shower gel, body wash, shampoo, or hair conditioner.

18. The personal care composition of any one of the preceding claims, wherein the personal care composition is a liquid facial soap.

19. A method of enhancing deposition of at least one topically active compound to skin of a subject, comprising applying the personal care composition according to any one of the preceding claims to the skin of the subject, wherein the method enhances an amount of the at least one topically active compound deposited as compared to a personal care composition that does not comprise at least one laurate surfactant.

20. The method of claim 19, wherein the method enhances deposition of the at least one topically active compound to the skin by at least about 0.1 pg / cm2, such as at least about 0.2 pg / cm2. about 0.3 pg / cm2, about 0.4 pg / cm2, or at least about 0.5 pg / cm2, as compared to a personal care composition that does not comprise at least one taurate surfactant.

21. Use of a personal care composition according to any of claims 1-18 for increasing the deposition of the at least one topically active compound on the skin of a subject when applying the composition to the skin.

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