Patent Description:
Taurine, or <NUM>-aminoethylsulphonic acid, is a non-proteinogenic amino acid that is known to have skin health benefits. For instance, taurine is known to exhibit antioxidant properties, regulate inflammatory reactions and enhance skin barrier repair. Taurine has been incorporated in various forms of personal care products and its skin health benefits have been documented both on lab skin models and clinical evaluations.

However, taurine shows stability issues in some formulations, such as bar soap. In particular, taurine tends to recrystallize on the surface of bar soap after aging. The recrystallized taurine can cause an undesirable look and/or feel to the bar soap product.

Taurine based surfactants, such as sodium methyl oleoyl taurate and sodium methyl cocoyl taurate, are known to be mild and high-foaming surfactants. They have been employed in certain personal care products. However, the taurine moiety of these surfactants is covalently bonded to a fatty acid group that does not dissociate in solution to provide for availability of free taurine. Because the taurine moiety is tied up in solution with the fatty acid group, one of ordinary skill in the art would not expect the taurate surfactants to have the above described skin health benefits associated with taurine.

While compounds such as taurine are known for improving skin health, discovering additional compounds that have skin health benefits and that are otherwise compatible with personal care and home care products would be a welcome advancement in the art. <CIT> discloses a composition for treating acne, while reducing irritation, wherein the composition comprises sodium cocoyl/oleyl taurate. <CIT> discloses skin and hair care compositions comprising sodium methyl cocoyl taurate. <CIT> discloses hair care compositions comprising sodium methyl cocoyl taurate. <CIT> discloses compositions for treating acne comprising sodium methyl cocoyl / oleyl taurate. <CIT> discloses cleaning compositions based on sodium methyl cocoyl taurate.

An embodiment of the present disclosure is directed to a bar soap composition. The composition is a bar soap composition made from ingredients as defined in the claims.

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 the preferred embodiment of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.

An embodiment of the present disclosure is directed to a composition made from an ingredient comprising at least one taurate surfactant chosen from a salt of a fatty acid amide of taurine, a salt of a fatty acid amide of N-methyl taurine, and combinations thereof as further defined in the claims. The composition is in a solid bar form.

The fatty acid chains of the taurate surfactants have <NUM> carbon atoms or more. In an embodiment, the taurate surfactant includes a fatty acid chain having <NUM> to <NUM> carbon atoms. The specified number of carbon atoms of the fatty acid chains described herein indicate the average chain length of the fatty acid chain, and lesser amounts of taurate surfactants having chain lengths that are shorter or longer that the lengths that are specified can be included, depending on the degree of purification used for making the particular ingredient, as would be understood by one of ordinary skill in the art. Blends of various lengths of fatty acids can be employed. Specific examples of such taurate surfactants include any of the compounds of general formula <NUM>:
<CHM>
wherein R<NUM> is a saturated or unsaturated, straight or branched alkyl or alkenyl group with <NUM> to <NUM> carbon atoms, such as <NUM> to <NUM> carbon atoms; R<NUM> is H or methyl and M is sodium, potassium, calcium, magnesium or ammonium. Suitable examples are potassium cocoyl taurate, potassium methyl cocoyl taurate, sodium caproyl methyl taurate, sodium cocoyl taurate, sodium lauroyl taurate, sodium methyl cocoyl taurate, sodium methyl lauroyl taurate, sodium methyl myristoyl taurate, sodium methyl oleoyl taurate, sodium methyl palmitoyl taurate, sodium methyl stearoyl taurate, sodium n-isostearoyl methyltaurate, calcium lauroyl taurate, magnesium methyl cocoyl taurate, sodium methyltaurate isopalmitamide and mixtures thereof. Still other examples of taurate surfactants include sodium methyltaurine cocoyl methyltaurate and sodium taurine cocoyl methyltaurate.

In an embodiment, the taurate surfactants are compounds in which R<NUM> is a methyl group and R<NUM> has <NUM> to <NUM> carbon atoms; such as, for example, sodium methyl oleyl taurate, sodium methyl cocoyl taurate and combinations thereof. In an embodiment, the taurate surfactant is sodium methyl oleyl taurate.

The personal care composition also does not include a medically effective amount of salicylic acid. In embodiments, the composition also does not include an olive oil-based compound and/or a quaternary ammonium salt. The phrase "olive oil-based compound" is defined herein to include olive oil and derivatives of olive oil that provide skin moisturizing benefits that are similar to those benefits associated with olive oil, including olive oil polyethyleneglycol (PEG) esters (including derivatives thereof, such as, but not limited to, olive oil PEG-<NUM> esters, olive oil PEG-<NUM> esters, olive oil PEG- <NUM> esters), olive oil extract, olive husk extract, olive leaf extract, olive oil unsaponifiables, olive oil fatty acid derivatives, olivamidopropyl (and derivatives thereof, such as, but not limited to, olivamidopropyl dimethylamine, olivamidopropyl dimethylamine lactate, and olivamidopropyl betaine), olivamide DEA, and olivamidopropalkonium chloride.

In an embodiment, the compositions of the present disclosure further comprise a carrier comprising a personal care ingredient. The personal care ingredient is selected from, for example, a fragrance, a preservative, a solvent, a propellant, a skin cell renewal agent, an anti-acne drug, an antiperspirant compound, an insect repellent agent, a sunscreen agent, a decomposition product of an oil or a fat, an exfoliant, and a mixture of two or more thereof.

The compositions of the present disclosure can have benefits similar to those of taurine when included in compositions that come in contact with the skin. These benefits can include at least one of reducing skin irritation and/or improving a cellular repair function of the skin.

A bar soap composition is made from ingredients comprising: at least one soap; and at least one taurate surfactant chosen from a salt of a fatty acid amide of taurine, a salt of a fatty acid amide of N-methyl taurine, and combinations thereof as further defined in the claims. The composition is in a solid bar form.

The at least one cleanser employed in the bar soap is a soap. The term "soap" is defined herein as a salt of a fatty acid. The soap is a salt of a C<NUM>-C<NUM> carboxylic acid. For example, the salt can comprise at least one compound chosen from an alkali metal, such as sodium, or alkylammonium salt of a C<NUM>-C<NUM> carboxylic acid, such as about a C<NUM>-C<NUM> carboxylic acid. The amount of soap can range from about <NUM> weight % to about <NUM> weight %, such as about <NUM> weight % to about <NUM> weight %, based on the total weight of the final bar soap composition.

The fatty acid soap may comprise a neutralized fatty acid. Typical fatty acids used for soaps include myristic acid, lauric acid, palmitic acid, and stearic acids, as examples. Sources of fatty acids include coconut oil, palm oil, palm kernel oil, tallow, avocado, canola, corn, cottonseed, olive, hi-oleic sunflower, mid-oleic sunflower, sunflower, palm stearin, palm kernel olein, safflower, and babassu oils.

The fatty acids may be neutralized with any base to form a soap. Typical bases include, but are not limited to, sodium hydroxide, potassium hydroxide, and triethanolamine. In certain embodiments, the fatty acid soap is formed from fatty acids neutralized by two or more bases. For example, sodium soaps, ammonium soaps, potassium soaps, magnesium soaps and calcium soaps can each be used alone as the soap ingredient, or as mixtures of two or more of the sodium, ammonium, potassium, magnesium and calcium soaps.

The soap can be made either in situ in amalgamate by mixing a source of fatty acids with the neutralizing agent, or the soap may be provided in a pre-made form. In certain embodiments, the molar amount of fatty acids is greater than the molar amount of neutralizing agent such that fatty acid remains in the amalgamate/pre-made soap. In some embodiments, the fatty acid soap is provided in the composition in the form of soap chips, as is known in the art.

Any of the taurate surfactants disclosed herein, or combinations thereof, can be employed in the bar soap compositions of the present disclosure. The taurate surfactants can be in any suitable concentrations so long as the taurate surfactants remain stable in the bar soap formulation. Examples of suitable taurate surfactant concentrations range from about <NUM>% to about <NUM>% by weight of the final bar soap composition, such as about <NUM>% to about <NUM>% by weight of the composition, or about <NUM>% to about <NUM>% by weight of the composition. In an embodiment, the taurate surfactant, such as those of formula <NUM>, are the only surfactants employed in the compositions of the present disclosure (e.g., where soap, rather than the first surfactant, is used as the cleanser), thereby providing one or more of the benefits described herein while potentially also acting as a surfactant.

Other ingredients can also be added to the bar soap. Examples of such ingredients include structuring agents, skin conditioning agents, chelating agents, foam boosters, preservatives, antimicrobial agents, exfoliating/scrubbing particles, glycerine, sodium chloride, titanium dioxide, colorants, fragrances and water. In an embodiment, the bar soap comprises at least one of glycerine and sodium chloride.

Suitable structuring agents (which may sometimes be referred to herein as structurants) include, for example, gellants selected from the group consisting of dibenzylidene sorbitol, dibenzylidene xylitol, dibenzylidene ribitol, and mixtures thereof. Other examples of structurants include alkali halides and alkali metal sulfates such as sodium chloride and sodium sulfate. Structurants may be incorporated into the compositions in an amount of up to <NUM> weight %, such as <NUM> to <NUM> weight % or <NUM> to <NUM> weight %, relative to the total weight of the final bar soap composition.

Skin conditioning ingredients (including emollients) include: various fats and oils (for example, soybean oil, sunflower oil, canola oil, and shea butter; glyceryl esters (for example, PEG <NUM> caprylie/caprie triglycerides, PEG <NUM> glyceryl cocoate, PEG <NUM> glyceryl cocoate, PEG <NUM> soy glyceride); alkyloxylated derivatives of dimethicone (for example, such as PEG/PPG-<NUM>/<NUM> Dimethicone and PEG-<NUM> Dimethicone); silicone esters (for example, Dimethicone PEG-<NUM> isostearate); silicone quaternium compounds (for example, Silicone Quaternium-<NUM>); lanolin quaternium compounds (For example, quaternium-<NUM>); cationic polymers (for example, Polyquaternium-<NUM> and Polyquaternium-<NUM>); and silicone polymers (for example, dimethiconol, dimethicone copolyol, alkyl dimethicone copolyol, and dimethicone copolyol amine, wherein the bar soap composition as defined in the claims does not include any of the skin conditioning ingredients which are surfactants other than taurate surfactant and soap surfactant.

A chelating agent may also be added to the to help retard oxidation. Any suitable chelating agent can be employed. For example, Ethylenediaminetetraacetic acid (EDTA) and salts thereof can be used as the chelating agent. The chelating agent is preferably present in amounts of about <NUM> wt. % to about <NUM> weight %, or about <NUM> weight % to about <NUM> weight % by total weight of the final bar soap composition, on an active basis.

The compositions of the present disclosure may also contain a preservative and/or antimicrobial agent in an amount of up to <NUM> weight %, or from about <NUM> wt. % to about <NUM> weight %, of the final bar soap composition on an active basis. Examples of preservatives include, but are not limited to, sorbic acid, potassium sorbate, methyl paraben, propyl paraben, imidazolinylurea, methylchloroisothiazolinone, and hydantoins (for example, DMDM hydantoin). Antimicrobial agents include, for example, triclocarban, triclosan and the like.

Particulate matter that aids exfoliation may further be incorporated into the bar soap. Particular matter includes polyethylene beads, jojoba beads, lufa, and oat flour.

Fragrance can be incorporated into the bar soap compositions in an amount of about <NUM> to about <NUM> wt. % of the final bar soap composition. The fragrance can include any active agent such as a phenolic, aldehyde, alcohol, nitrile, ether, ketone or ester and the like.

Water may be present in the bar soap in an amount of up to about <NUM> weight %, up to <NUM> weight %, or up to <NUM> weight % by total weight of the final bar soap composition. Preferably, water is present in an amount of from <NUM> weight % to <NUM> weight %, or from <NUM> weight % to <NUM> weight % or from <NUM> to <NUM> weight % of the final bar soap composition. The water can be added separately or made available from water contained in the other ingredients.

The pH of the bar soap composition can range, for example, from about <NUM> to about <NUM>, such as about <NUM> to about <NUM>, or about <NUM> to about <NUM>. The pH test method is based on <NUM> of bar soap dissolved into <NUM> of water to make a <NUM> weight % soap solution, which is then tested for pH level.

The final bar soap composition does not include a medically effective amount of antimicrobial agents, such as triclocarban or salicylic acid, for topical applications. The term "not a medically effective amount" as used herein is defined to mean less than <NUM>% by weight. In an embodiment, the final bar soap composition includes less than <NUM>% or less than <NUM>% of antimicrobial agents, such as triclocarban or salicylic acid, by weight, relative to the total weight of the final bar soap composition.

When added to bar soap formulations, the taurate surfactants, as described herein, can have one or more of the following advantages: reducing skin irritation compared to the same composition made without the taurate surfactant, improving a cellular repair function of the skin compared to the same composition made without the taurate surfactant, or avoiding the problem of recrystallization of taurine in the bar soap, as described above. Thus, employing the taurate surfactants of the present disclosure in bar soap may provide one or more of the same skin health benefits provided by taurine, while avoiding the known recrystallization problems associated with taurine.

As described above, any of the compositions of the present disclosure can be used to alleviate skin irritation, skin inflammation and/or to improve the cellular repair function of the skin. Another embodiment of the present disclosure is directed to a composition for use as a medicament in a method of improving the cellular repair function of the skin. The method comprises applying an effective amount of any of the compositions described in appended claim <NUM> to the skin of a subject.

The following in vitro studies evaluate the skin health benefits of sodium methyl oleoyl taurate in comparison with taurine at the same weight concentration. Comparable effects on anti-irritation/anti-inflammation and cellular repair were observed. Results suggest that this new discovery may allow the formulation of sodium methyl oleoyl taurate in bar soaps to achieve the skin health benefits of taurine and avoid taurine stability issues, such as recrystallization.

The materials used in the examples below were as follows:.

Three different culture medium samples were prepared. A control medium that included a Dulbecco's modified Eagle's medium (DMEM) comprising actives of <NUM>% Fetal Bovine Serum and <NUM>% Penicillin Streptomycin; a taurine medium that was the same as the control medium but included <NUM>% by weight Taurine; and a taurate medium that was the same as the control medium but included <NUM>% by weight Sodium Methyl Oleoyl Taurate.

To determine the effect of both Taurine (<NUM>%) and Sodium Methyl Oleoyl Taurate (<NUM>%) on the cellular repair function, in vitro experiments were conducted using HaCaT cells. HaCaT cells are a spontaneously transformed aneuploid immortal keratinocyte cell line from adult human skin. Three sample wells of the HaCaT cells were each grown until <NUM>% confluent. After that, each well was scratched with a <NUM> microliter (ul) tip (to create the gap) and washed twice with <NUM> milliliter (ml) of phosphate buffered saline ("PBS") to eliminate dead floating cells. Following that, each one of the three sample wells were treated with <NUM> of one of the three culture medium samples: one with the control medium, one with the taurine (<NUM>%) medium, and one with the sodium methyl oleoyl taurate (<NUM>%) medium. Then, initial measurements of gap distance were taken using a microscope (OLYMPUS IX71). Next, the treated cells were incubated for <NUM> hours and measurements were taken again using the same microscope. The percentage of gap distance reduction is shown in <FIG>.

The migration assay provided a measure of the cell migration in order to evaluate the active's potential in promoting cell multiplication, and thus inducing barrier repair. The smaller the gap, the greater the migration rate, which suggests better cellular repair function (e.g., improved skin barrier repair). As shown in <FIG>, the cells treated for <NUM> hours with the same weight concentration of sodium methyl oleoyl taurate and taurine showed comparable enhancement in cell migration rate.

To document the effect on skin inflammation, in vitro experiments using 3D EpiDerm skin models (SIT <NUM> skin irritation model, MatTek Corporation, Ashland, MA) were conducted. An irritant chemical, sodium dodecyl sulfate (<NUM> wt. % SDS), was used to induce skin irritation in in vitro skin samples. After the inducement of skin irritation, the in vitro skin samples were each treated topically with one of two <NUM> ul test solutions (either a <NUM>% Taurine in PBS solution or a <NUM>% Sodium methyl oleoyl taurate in PBS solution) for <NUM> hour in a tissue culture incubator (<NUM> degree C, <NUM>% CO<NUM>). Following the incubation, the skin samples were washed with PBS and placed in a culture medium and further incubated for <NUM> hours. Tissue was harvested and homogenized for a multiple inflammation biomarker assay, testing levels of IL-<NUM>, IL-<NUM>, IL-<NUM> and TNF-a. Biomarkers were analyzed by a Milliplex assay kit. (Millipore, Billerica, MA).

The irritant chemical, sodium dodecyl sulfate (SDS), that was used is commonly used as a negative control in irritation/inflammation assays on MatTek tissue. The multiple biomarker assay of Example <NUM> measured the levels of proinflammatory cytokines, including IL-1a, IL-<NUM>, IL-<NUM>, TNF-a, in one assay to evaluate the level of skin irritation/inflammation. The more cytokines released, the greater the irritation and/or inflammation potential. As shown in <FIG>, SDS induced the expression of cytokines IL-1a, IL-<NUM>, IL-<NUM> and TNF-a. However, with the co-treatment of sodium methyl oleoyl taurate or taurine, the cytokine levels were suppressed. It can be concluded that reduced irritation potential is found in tissues treated with sodium methyl oleoyl taurate compared to the samples not treated with either sodium methyl oleoyl taurate or taurine.

Based on the above described cell migration assay and inflammation assay results, sodium methyl oleoyl taurate shows benefits in promoting skin cellular repair (e.g., skin barrier repair) and acting against skin irritation/inflammation that are comparable to those of taurine. The results suggest that sodium methyl oleoyl taurate can potentially be used in bar soap formulations as well as other product forms to deliver the skin benefits that have been previously documented with taurine. And, sodium methyl oleoyl taurate potentially provides improvements over taurine when used in various products (e.g., bar soap and the like) because it is hypothesized that sodium methyl oleoyl taurate may have improved stability in bar soap and thus may not cause the undesirable look and/or feel associated with recrystallized taurine in bar soap formulations.

Any of the taurate surfactants of the present disclosure can be employed to make a bar soap formulation, as described herein. Example ingredients for such bar soap formulations are shown in Table <NUM> below.

The percentages in Table <NUM> are weight percentages based on the total weight of the final bar soap composition. All ranges are exemplary only, so that amounts outside of the ranges shown can be employed. The ingredients can be mixed and the bar soap shaped using any suitable method that is known in the art or yet to be developed.

Two separate combar samples were formulated, one with taurine and one with sodium methyl oleoyl taurate. Both the taurine and sodium methyl oleoyl taurate were formulated at the same molar concentration in the combar samples. The weight concentrations of taurine and methyl oleoyl taurate in their respective combar bases was as follows:.

Samples for testing were made by mixing the taurine combar and taurate combar in PBS (<NUM>% weight by volume combar base of each of the taurine combar and sodium methyl oleoyl taurate combar in PBS).

To document skin inflammation, in vitro experiments were conducted using 3D EpiDerm skin models (SIT <NUM> skin irritation model, MatTek Corporation, Ashland, MA). Separate In vitro skin samples were treated topically with 30ul each of the taurine combar and taurate combar test samples for <NUM> hour in a tissue culture incubator. Following the incubation, the skin samples were washed with PBS, placed in a culture medium and allowed to continued to incubate for <NUM> hours. Tissue was harvested and homogenized for a IL-1a assay. IL-1a levels were analyzed using a Human IL-<NUM> alpha/IL-1F1 Quantikine ELISA kit available from R&D Systems, Minneapolis, MN. Among cytokines released along the inflammation pathway, IL-1a is recognized as a prominent irritation biomarker. The more IL-1a that is released, the greater is the irritation potential.

Due to high pH and the presence of surfactants in the formulation, it was expected that the combar base would show significantly higher irritation levels compared to untreated skin samples. Thus, the combar base was used as a negative control on the MatTek tissue.

Claim 1:
A bar soap composition made from ingredients comprising:
a taurate surfactant chosen from a salt of a fatty acid amide of taurine, a salt of a fatty acid amide of N-methyl taurine, and combinations thereof, wherein the fatty acid of the taurate surfactant has <NUM> carbon atoms or more,
a soap surfactant consisting of a salt of a C<NUM>-C<NUM> carboxylic acid,
wherein the bar soap composition does not include any surfactant other than the taurate surfactant and the soap surfactant,
wherein the bar soap composition does not include a medically effective amount of salicylic acid, and
wherein the composition is in a solid bar form.