EA044775B1 - ANTIPERSPIRANT COMPOSITIONS - Google Patents

Description

Field of technology

The present invention relates to antiperspirant compositions and methods for reducing sweating. In particular, it relates to compositions and methods that do not involve the use of aluminum salts.

State of the art

As a rule, in antiperspirant compositions, astringent aluminum or aluminum-zirconium salts are used to provide a deodorizing effect. Such salts in antiperspirants block the upper part of the sweat glands and thereby reduce the secretion of sweat from them.

Many researchers have studied alternative, aluminum-free antiperspirant actives and compositions. Some of them are associated with a decrease in sweat production by the secretory spiral of the sweat glands; however, the active substances acting in this way may be regarded as therapeutic in nature, which may be undesirable for formulations intended for use as cosmetics.

Alternative, aluminum-free antiperspirant actives and compositions have also been developed that act by blocking the sweat glands.

WO 2010/145905 (Unilever, 2010) describes the use of lamellar phase stabilized oil-in-water emulsions as antiperspirant agents.

EP 550960 A1 (Unilever, 1992) describes the use as an antiperspirant active of an amphiphilic material which, on contact with sweat, forms a water-insoluble liquid crystalline phase with a periodicity greater than one-dimensional.

WO 2018/111664 (Colgate, 2018) describes antiperspirant compositions containing a zinc-based antiperspirant active, a thickener containing a C ₁₄ -C ₂₂ fatty acid salt, and a carrier containing a polyhydric alcohol, optionally together with water.

There are also many known antiperspirant salts containing sodium stearate as a structuring agent; however, stearic acid is not a fatty acid used in the present invention, and such use does not in situ form sodium soap, unlike the present invention.

There is a limited number of publications devoted to calcium salts of organic acids used in antiperspirant compositions.

WO 2015/051805 A1 (Riemann Trading Aps, 2015) describes anhydrous antiperspirant compositions containing aluminum chloride or any of its hydrates, at least one calcium or magnesium salt of an organic acid and a water-miscible solvent. However, a mixture of carboxylic acids and water-soluble salts in accordance with the present invention is not known from the prior art.

CA 1097223 (American Cyanamid Company, 1981) describes a deodorant stick containing 20-50% ethanol, 15-25% aluminum chlorohydrate, 15-60% C ₁₆ fatty alcohol and 0-10% magnesium or calcium salt of a long-chain fatty acid.

Brief description of the invention

The object of the present invention is to reduce sweating from the surface of the human body, especially in the axillary areas, otherwise known as the armpits.

Another object of the present invention is to reduce sweating from the surface of the human body by blocking or partially blocking the sweat glands without the use of astringent salts of aluminum or zirconium.

In a first aspect of the present invention, there is provided an oil-in-water emulsion containing (i) a C ₁₀ -C ₂₂ fatty acid that is a liquid; (ii) an emulsifier for a C ₁₀ -C ₂₂ fatty acid; and (iii) a water-soluble metal salt capable of forming a water-insoluble salt with a C ₁₀ -C ₂₂ fatty acid at a pH greater than 6.

In preferred embodiments, the water-insoluble salt is capable of forming a solid water-insoluble salt with a C ₁₀ -C ₂₂ fatty acid at a pH greater than 6, particularly at a temperature of 37°C.

A second aspect of the present invention provides a method for reducing sweating, comprising topical application of an emulsion according to the first aspect of the present invention.

In a third aspect of the present invention, there is provided a method for making an antiperspirant composition comprising the steps of emulsifying a C ₁₀ -C ₂₂ fatty acid in a liquid in an aqueous dispersion medium by adding a water-soluble metal salt to the aqueous dispersion medium, wherein the water-soluble metal salt is capable of forming a water-insoluble salt with _C10C22 fatty acid at pH greater than 6.

In a third aspect of the present invention, the addition of the water-soluble metal salt to the aqueous medium may occur before or after emulsification of the C ₁₀ -C ₂₂ fatty acid.

In a third aspect of the present invention, emulsification of a C ₁₀ -C ₂₂ fatty acid is achieved using an emulsifier.

A fourth aspect of the present invention provides a method for reducing sweating comprising the pH-triggered in situ formation of a water insoluble salt of a C ₁₀ -C ₂₂ fatty acid, wherein the water insoluble salt is formed from a topically applied C ₁₀ -C ₂₂ fatty acid, which is a liquid, and a water-soluble metal salt.

In a fourth aspect of the present invention, the C ₁₀ -C ₂₂ fatty acid is typically prepared in the form of an oil in water emulsion stabilized by an emulsifier. Preferably, the water-soluble metal salt is dissolved in the aqueous phase of the oil-in-water emulsion.

The method of reducing sweating is carried out on human skin, in particular in the armpits.

Formation in situ of an active antiperspirant substance, i.e. water-insoluble salt of CioC22 fatty acid, means the formation of this substance on the skin of the human body, in particular, in the ducts of the sweat glands located in the human skin, especially in the armpits.

The peculiarity of the pH-initiated formation of the active antiperspirant substance is due to the fact that the pH of sweat on the skin is slightly higher than the pH of the C ₁₀ -C ₂₂ fatty acid oil-in-water emulsion. In preferred embodiments, the oil-in-water emulsion of the C ₁₀ -C ₂₂ fatty acid has a natural pH or is slightly acidified, for example to a pH of 3.5-4.5. When applied to the skin (sweat pH is approximately 6 to 7), the water-soluble metal salt forms a gel with the fatty acid and causes blockage of the sweat gland ducts.

A fifth aspect of the present invention provides the use of an in situ produced water insoluble salt of a liquid C ₁₀ -C ₂₂ fatty acid as an antiperspirant.

Detailed Description of the Invention

All quantities, parts, percentages and ratios presented herein are by weight and refer to the total weight of the composition unless otherwise indicated. This also applies to examples.

As used herein, the term including is non-exclusive.

The parameters presented in the present invention, set forth in relation to one aspect of the invention, apply, to the extent possible, in relation to any other aspect of the present invention.

The parameters presented in the present invention, set forth in relation to one feature, are preferably used in combination with the parameters set forth in relation to one or more other features.

When a component presented herein is referred to in the singular, it is understood that more than one component of a given type may be present and all of them must be included in the calculation in any specified amount or ratio.

Presented in the present invention, the states of aggregation such as solid, liquid and gas refer to the mentioned state of aggregation at a temperature of 25°C and atmospheric pressure. For example, the liquid C ₁₀ -C ₂₂ fatty acid used in the present invention is liquid at a temperature of 25°C and a pressure of one atmosphere.

The viscosities presented in the present invention are measured at 37°C and a shear rate of 0.01 s ^-1 .

As used herein, the terms gel and gelation refer to states of matter and structure of state of matter, which may include crystalline solids, amorphous solids, or viscous states of matter in which blocking of sweat glands may occur. Said gel generally has a viscosity of at least 2 Pa.s, preferably at least 5 Pa.s, more preferably at least 10 Pa.s and most preferably at least 100 Pa.s. The gel may be solid, crystalline or amorphous, or may have a viscosity of up to 1000 Pa.s.

Presented in the present invention, references to compositions [according to the present invention] are equated to emulsions [according to the present invention].

Fatty acid.

The C ₁₀ -C ₂₂ fatty acid used in accordance with _the present invention must _be liquid. Such fatty acids are generally unsaturated, meaning that they have one or more unsaturated carbon-carbon bonds.

Preferably, the C ₁₀ -C ₂₂ fatty acid used in this manner is liquid at 20°C, and more preferably it is liquid at 10°C. The relatively low melting point of the fatty acid may increase the stability of the compositions of the invention when stored at low temperatures.

The C10-C22 fatty acid preferably contains 14 to 20 carbon atoms, more preferably 16 to 18 carbon atoms, and most preferably 18 carbon atoms. Preferred C18 fatty acids are unsaturated acids having at least one double bond. In particular, preferred fatty acids are oleic, linoleic, linolenic and ricinoleic acids. Particularly preferred are oleic and ricinoleic acids.

In some embodiments, mixtures of C ₁₀ -C ₂₂ fatty acids may be used.

The total C ₁₀ -C ₂₂ fatty acid content in the compositions of the present invention is preferably from 3%, more preferably from 4.5% and most preferably from 6%.

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Independently of each other and in accordance with each of the preferred lower limits of content indicated above, the total C ₁₀ -C ₂₂ fatty acid content is preferably up to 15%, more preferably up to 12.5%, and most preferably up to 10%.

In some preferred embodiments, the total amount of C ₁₀ -C ₂₂ fatty acid is from 5 to 10%.

A water-soluble metal salt.

The water-soluble metal salt has a solubility in water of at least 10 g/L and preferably at least 100 g/L, the solubility is measured at 25°C.

Typically, a water-soluble salt of a polyvalent metal, preferably divalent, and more preferably selected from calcium and zinc salts, is used. Most preferred are zinc salts, especially when the fatty acid is ricinoleic acid.

In some embodiments, mixtures of water-soluble metal salts may be used.

The total content of water-soluble metal salts in the compositions of the present invention is preferably 0.75%, more preferably 1.0%, and most preferably 1.3%. Independently of each other and in accordance with each of the preferred lower limits mentioned above, the total amount of water-soluble metal salt is preferably up to 3.0%, more preferably up to 2.5%, and most preferably up to 2%.

In some preferred embodiments, the total amount of water-soluble metal salts is from 1.5 to 2.0%.

The molar ratio of C ₁₀ -C ₂₂ fatty acid to water-soluble metal salt cation (divided by its valency) is preferably selected from 1:2 to 2:1, more preferably from 2:3 to 3:2, and most preferably about 1 :1. Thus, neither an excessive amount of C ₁₀ -C ₂₂ fatty acid nor an excessive amount of water-soluble metal salt is wasted. More precisely, these ratios can be expressed as preferably 33:67 to 67:33, more preferably 40:60 to 60:40, and most preferably about 503:50.

When the water-soluble salt contains a divalent metal, such as, for example, a calcium salt or a zinc salt, in particular calcium chloride or zinc chloride, the molar ratio of the water-soluble metal salt to C ₁₀ -C ₂₂ fatty acid is preferably selected in the range of 1: 4 to 1:1, more preferably 1:3 to 2:3, and most preferably about 1:2. More precisely, these ratios can be expressed as preferably from 20:80 to 50:50; more preferably from 25:75 to 40:60 and most preferably about 33:67.

A water-insoluble salt formed from a C ₁₀ -C ₂₂ fatty acid at a pH greater than 6.

A distinctive feature of the present invention is the ability of a water-soluble metal salt to form a water-insoluble salt with a C ₁₀ -C ₂₂ fatty acid at a pH greater than 6. This can be established by combining the components at a pH greater than 6 and a temperature of 20°C, 25°C or 37°C. In the preferred test method, the components are converted at pH 3.5 and then the pH of the mixture is adjusted to greater than 6 with a base.

As used herein, the term water insoluble means a solubility in water of less than 10 g/L at 25°C, preferably less than 1 g/L.

Emulsifier.

An emulsifier is an essential component of the compositions of the present invention. Any emulsifier that allows emulsification of C ₁₀ -C ₂₂ fatty acid in water at a temperature of 20°C can be used. Mixtures of emulsifiers can also be used.

Preferably, the emulsifier or mixture of emulsifiers contains a non-ionic emulsifier.

In some preferred embodiments, a mixture of emulsifiers is used, such as a mixture of nonionic emulsifiers or a mixture of a nonionic emulsifier and an anionic emulsifier.

The total amount of emulsifier in the compositions of the present invention is preferably 0.5%, more preferably 1.0%, and most preferably 1.3%. Independently of each other and in accordance with each of the preferred lower levels indicated above, the total amount of emulsifier is preferably up to 10%, more preferably up to 7.5% and most preferably up to 5%.

The ratio of emulsifier to C ₁₀ -C ₂₂ fatty acid is preferably 1:10, more preferably 1:8, and most preferably 1:6. Independently of each other and in accordance with each of the preferred ratios indicated above, the ratio of emulsifier to C ₁₀ -C ₂₂ fatty acid is preferably up to 2:3, more preferably up to 1:2 and most preferably up to 1:3.

In some preferred embodiments, the emulsifier comprises a polyglyceryl ether, such as polyglyceryl-3 stearate. When the emulsifier contains such substances, the ratio of emulsifier to C ₁₀ -C ₂₂ fatty acid is preferably from 1:10, more preferably from 1:7 and most preferably from 1:4. Independently of each other and in accordance with each of the preferred ratios indicated above, the ratio of emulsifier to C ₁₀ -C ₂₂ fatty acid is preferably up to 1:1, more preferably up to 9:11 and most preferably up to 2:3. In particular

- 3 044775 In a preferred embodiment, the ratio of emulsifier-containing polyglyceryl ether to

C ₁₀ -C ₂₂ fatty acid is from 1:4 to 2:3, i.e. from 20:80 to 40:60.

In some preferred embodiments, the emulsifier contains a linear alkyl ethoxylate, such as Steareth-20. Preferred linear alkyl ethoxylates contain at least 10 ethoxylate units per molecule, and in particular, preferred linear alkyl ethoxylates contain at least 15 ethoxylate units per molecule.

When the emulsifier consists only of a linear alkyl ethoxylate, the ratio of emulsifier to C ₁₀ -C ₂₂ fatty acid is preferably from 5:95 to 30:70, more preferably from 10:90 to 28:72, and most preferably from 15:85 to 25:75 .

Preferred emulsifiers and preferred ratios of emulsifier and C ₁₀ -C ₂₂ fatty acid are important for the stability of the composition, by which is meant its phase stability, i.e. absence of phase separation over a long period.

Additional signs.

An extremely important additional feature is the thickener. The thickener increases the viscosity of the compositions of the present invention, which may make them more attractive to the consumer. The thickener may also maintain the phase stability of the composition and/or the ability of the composition to remain in the roll-on dispenser without leaking.

Thickeners suitable for use in the present invention include cationic and nonionic polymers, in particular cationic and nonionic polymer thickeners of natural origin, examples of which include guar gum and derivatives, as well as cellulose derivatives such as hydroxyethylcellulose. Particularly preferred thickeners are cationic polymers, in particular guar gum and/or derivatives thereof.

The thickener is usually used in an amount of from 0.1 to 10% of the total composition. In preferred embodiments, the thickener is present in an amount of 0.2 to 5%, and in more preferred embodiments, it is present in an amount of 0.3 to 3% of the total composition.

In a preferred embodiment, the composition of the present invention is stored in and applied from a roll-on dispenser. The compositions of the present invention are particularly suitable for storage and application from a roll-on dispenser designed for long-term storage in an inverted position. For the avoidance of doubt, a roll-on dispenser in an inverted position has a roll-on applicator, typically a ball, located at the bottom of the container containing the composition.

The thickener is an extremely important component of compositions that are stored and dispensed from a roll-on dispenser.

In another preferred embodiment, the composition of the present invention is stored in and applied from a spray or squeeze-operated dispenser.

In another preferred embodiment, the composition is in the form of a cream, typically having a viscosity of 10 to 100 Pa.s. Such compositions may have particularly good storage stability.

The thickener is an extremely important component of compositions that are stored and applied from a roll-on dispenser.

In another embodiment, the composition is a soft solid, typically having a viscosity of 100 to 1000 Pa.s. The thickener is an essential component of such compositions. Such compositions may have particularly good storage stability.

In another embodiment, the composition is in the form of a solid bar. The thickener is an essential component of such compositions.

A preservative is a preferred additional component in the compositions of the present invention. The preservative serves to reduce or eliminate the proliferation of microorganisms in the compositions of the present invention. Preservatives are typically used in a total amount of 0.05 to 3%, preferably 0.1 to 2%, and most preferably 0.4 to 1%.

Suitable preservatives for use in the present invention include 2phenoxyethanol, iodopropynyl butylcarbamate, C ₁ -C ₃ alkylparabens, sodium benzoate, caprylyl glycol and EDTA. In particular, preferred preservatives are 2-phenoxyethanol, iodopropynyl butyl carbamate, sodium benzoate, capryl glycol and EDTA, and 2-phenoxyethanol and iodopropynyl butyl carbamate are particularly preferred.

The antimicrobial deodorant active is a preferred additional component in the compositions of the present invention. Such components serve to reduce or eliminate the odor of sweat by reducing or otherwise interfering with the activity of microorganisms living on human skin and causing the formation of an unpleasant odor.

The antimicrobial deodorant active may also serve as a preservative for the present composition.

In the case of using an antimicrobial deodorant agent, its content in the composition is from 0.01 to 3% and, in particular, from 0.03 to 0.5%.

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Preferred antimicrobial deodorant agents have a minimum inhibitory concentration (MIC) of 1 mg.ml ^-1 or less, in particular 200 μg.ml ^-1 or less, and especially 100 μg.ml ^-1 or less. The MIC of an antimicrobial agent is the minimum concentration of agent required to significantly inhibit microbial growth. Inhibition is considered significant if a reduction in Staphylococcus epidermidis inoculum growth of 80% or more is observed compared to control medium without antimicrobial agent over a period of 16 to 24 hours at 37°C. Details of suitable methods for determining MICs can be found in Antimicrobial Agents and Susceptibility Testing, C. Thornsberry, (in Manual of Clinical Microbiology, 5th Edition, Ed. A. Balows et al., American Society for Microbiology, Washington DC, 1991). A particularly suitable method is the broth macrodilution method described by DF Sahm and JA Washington II in Chapter 110 of the above publication (pages 1101-1111). The MICs of antimicrobials suitable for inclusion in the compositions of the present invention are for triclosan: 0.01-10 μg.mlm ^-1 (J. Regos et al., Dermatologica (1979), 158: 72-79) and for farnesol: approximately 25 µg.mlm ^-1 (K. Sawano, T. Sato, and R. Hattori, Proceedings of the 17th IFSCC International Conference, Yokahama (1992) p.210-232). In contrast, ethanol and similar alkanols have MICs greater than 1 mg.ml ^-1 .

Suitable organic antimicrobial agents include bactericidal agents, for example quaternary ammonium compounds such as cetyltrimethylammonium salts, chlorhexidine and its salts, and diglycerol monocaprate, diglycerol monolaurate, glycerol monolaurate and similar materials described in Deodorant Ingredients, S.A. Makin and M.R. Lowry, Antiperspirants and Deodorants, Ed. K. Laden (1999, Marcel Dekker, New York). More preferred antimicrobial agents for use in the compositions of the present invention are polyhexamethylene biguanide salts (also known as polyaminopropyl biguanide salts), an example of which is Cosmocil CQ TM available from Zeneca PLC, preferably used in an amount of up to 1% and more preferably in an amount of 0 .03 to 0.3% by weight, 2',4,4'-trichloro,2-hydroxydiphenyl ether (triclosan), preferably used in an amount up to 1% by weight of the composition and more preferably in an amount of 0.05-0.3 %, and 3,7,11-trimethyldodeca-2,6,10-trienol (farnesol), preferably used in an amount of up to 1% by weight of the composition and more preferably in an amount of up to 0.5%.

Other suitable organic antimicrobial agents are transition metal complexing agents, as described, for example, in WO 01/52805. Preferably, complexing agents based on transition metals are used that have a binding coefficient for iron (III) of more than 10 ²⁶ , for example, diethylenetriaminepentaacetic acid and its salts.

Antioxidants may be preferably used in certain compositions, in particular those containing unsaturated fatty acids. Suitable antioxidants include butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and pentaerythrityl tetra-di-t-butyl hydroxycinnamate. Antioxidants can be used in an amount of 0.05 to 5%, in particular 0.075 to 2.5% and especially 0.1 to 1%.

Additional desirable components include certain sensory modifiers. Such materials are preferably used in amounts up to 20% by weight of the composition. Emollients, humectants, volatile oils, fixed oils, and ground solids that impart a smooth feel are relevant categories of sensory modifiers. Examples of such materials include cyclomethicone, dimethicone, dimethylconol, isopropyl myristate, isopropyl palmitate, talc, micronized silica (eg Aerosil 200), particulate polyethylene (eg Acumist B18), polysaccharides, corn starch, C ₁₂ -C ₁₅ alcohol benzoate, myristyl PPG-3 ether, octyldodecanol, C ₇ -C ₁₄ isoparaffins, di-isopropyl adipate, isosorbitol laurate, PPG-14 butyl ether, glycerin, hydrogenated polyisobutene, polydecene, titanium dioxide, phenyl trimethicone, dioctyl adipate and hexamethyldisiloxane.

An additional desirable component is also a flavoring agent. Suitable materials contain conventional fragrances, such as perfume oils, and also contain so-called de-fragrancers, as described in EP 545556 and other publications. The contents of such substances are preferably up to 4% by weight, in particular from 0.1 to 2% by weight, and especially from 0.7 to 1.7% by weight.

Examples

The present invention will now be illustrated by the following non-limiting examples.

Raw materials indicated in table. 1 was used in preparing the examples below.

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Table 1

Name used Chemical name Trade name Name by international nomenclature of cosmetic ingredients MNKI Provider Fatty acid Oleic acid Oleic acid Oleic acid TCI Linoleic acid Linoleic acid Linoleic acid TCI Linolenic acid Linolenic acid Linolenic acid TCI Ricinoleic acid Ricinoleic acid Ricinoleic acid TCI Emulsifiers Stearet-20 Brij S20 Stearet-20 Kroda (C rod a) SARV Tegobetain F 50 Cocamidopropyl betaine Local manufacturer Brij S2 Stearet-2 Stearet-2 Croda SLES-3EO Teharop N703GT Teharop N703GT [70% aqueous solution] Sodium laureth sulfate BASF Span 20 Sorbitan monolaurate Sorbitan Laurate Croda Twin 80 Polyoxyethylene sorbitan monooleate Polysorbate 80 TCI Tri gop X-100 4-(1,1,3,3- tetramethylbutyl)phenyl- polyethylene glycol Octoxynol-9 Merck LDAO N,N-dimethyldodecylamine N-oxide (30% aqueous solution) Lauryl dimethyl N-oxide Sigma Aldrich

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SME-C16 Sulfonic Methyl Ester Sodium methyl 2-sulfopalmitate KLK Oleo Metal salts Calcium chloride Chloride dihydrate calcium Calcium chloride Chern-Lab Zinc chloride Zinc chloride Zinc chloride Sigma Aldrich Thickeners Jaguar S Guar gum Cyamopsis tetragonoloba gum Solvay Novecare PEG 35000 Poly(ethylene glycol) — Merck Natrosol 250 HR Hydroxyethyl cellulo for Hydroxyethylcellulose Ashland Jaguar C-162 Jaguar C-162 Hydroxypropylguar hydroxypropyltrimonium chloride Solvay SP-100 N-Hance TM SP-100 Acrylamidopropyltrimonium chloride/acrylamide copolymer Ashland Guar BF-7 Esaflor BF 7 Hydroxypropyltrimonium chloride Lamberti Silica particles Hydrophobic fumed silica (highly dispersed silicon oxide) Unilever Preservatives 2phenoxyethano l 2-phenoxyethanol Phenoxyethanol Sigma-Aldrich Glycatyl L Glycatyl L Iodopropynylbutylcarbamate Lonza PEG-4 Laurate PEG-4 Dilaurate Propylene glycol Polyglycerol emulsifiers PG-3-S Polyaldo® 3-1-S Polyglyceryl-3 stearate Lonza PG-6-D Polyaldo® 6-2-S Polyglyceryl-6 stearate Lonza PG-10-S Polyaldo® 10-1-S (granulated) Polyglyceryl-10 stearate Lonza PG-1O-0 Polyaldo® 10-1-0 Polyglyceryl-10 oleate Lonza PG-10-CC Polyaldo® 10-1-CC Polyglyceryl-10 oleate Polyglyceryl-10 caprylate/caprate Lonza

Study 1.

A simple emulsion composition containing 7% oleic acid, 1.85% calcium chloride (always a dihydrate in the examples presented) and 1.6% Steareth-20-20 was prepared and adjusted to pH 3.5 with a small amount of hydrochloric acid. The emulsion was prepared at ambient temperature using a high shear mixer operating at 3500 rpm for 3 min and then at 24000 rpm for 10 min. The emulsion was milky white in color and remained stable for one month at ambient temperature. 2 ml of the emulsion composition was applied to a piece of woven cotton on a microscope slide. The pore size (space between warp and weft) of cotton fabric was approximately 80 microns, which is comparable to the average size

- 7 044775 pores of sweat glands in the armpits (from 90 to 100 microns). In fig. Figure 1 shows an image of the treated tissue obtained using a microscope. The thick black bars at the bottom of the image indicate a scale segment equal to 100 microns. The pH of the cotton composition was then adjusted to 6 using a 6M sodium hydroxide solution (approximately 10 microliters). After adjusting the pH value, the pores in the cotton fabric were blocked by a crystalline phase that shone under the polarized light used in the study. In fig. Figure 2 is a microscope image of treated cotton after adjusting the pH to 6 (same scale as Figure 1).

This study illustrates the potential that the compositions of the present invention have for blocking pores of about 80 microns in diameter, including sweat pores in the axillary areas (axillae). The pH of sweat on the skin in the armpits is typically about 6.5, so when applied topically to the axillae the pH value of the composition, equal to 3.5 during preparation, will be balanced under natural conditions and will increase. As the pH increases, the compositions of the present invention cause the formation of metallic fatty acid soap in situ, which forms plugs in the sweat glands, thereby reducing sweating.

Study 2.

In Study 1, the prepared sample had a low viscosity (5 mPa.s, measured as described below). Variants of the composition of Study 1 were prepared using various thickeners and emulsifiers in an attempt to make more viscous samples (more suitable for use in roll-on dispensers). The samples were prepared as follows.

The thickener and/or emulsifier was dissolved in water with stirring. The pH of the resulting solution was adjusted to 3.5 with a small amount of hydrochloric acid. Then this solution was poured into the fatty acid and a metal salt and a preservative were added. The resulting emulsion premix was then processed in a high shear mixer at 3500 rpm for 2 minutes and then at 15000 rpm for 8 minutes. The components used and their quantities are indicated in the corresponding tables.

Examples 1 to 9.

The samples presented in table. 2 and others were prepared as described above. Along with the composition details, in table. 2 describes in detail the viscosity of the composition in finished form (with a pH of 3.5) and the viscosity of the composition after adjustment to pH 6 (6 M sodium hydroxide solution). The table also provides data on the stability of the compositions during storage.

For all of these samples without exception.

Instability manifested itself through phase separation.

The viscosity of only those samples that remained stable for at least 1 week was reported. Viscosity unit - Pa.s. Viscosity measurements were carried out at 37°C. Viscosity was measured over a range of shear rates, but the values given are for the initial measurement at 0.01 s ^-1 . A Bohlin Gemini viscometer with a cone-plate configuration was used.

Viscosity at pH 3.5 indicates the effectiveness of the thickener used.

The increase in viscosity from pH 3.5 to pH 6 provides insight into the extent to which the formulation gels in this pH range and demonstrates its ability to plug sweat glands in situ when applied to the armpits.

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table 2

Component Example 1 2 3 4 5 6 7 8 9 Oleic acid 7 10.5 10.5 7 7 7 7 7 7 Stearet-20 1.6 2.4 2.4 1.6 1.6 0.8 0.8 3.2 1.6 SARV — — — — — 0.8 — — Stearet-2 — — — 0.8 — Calcium chloride 1.85 2.775 2.775 1.85 1.85 1.85 1.85 1.85 1.85 JaguarS 0.6 0.6 — — 0.6 0.6 0.6 Natrosol 250 HR — — 0.65 — — — — — — Jaguar C-162 — — — 0.8 — — — — — Guar BF-7 — — — — 1,o — — — — SP-100 — — — — — — — — 0.8 Phenoxyethanol 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Glycatyl L 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Water Up to 100 Viscosity at pH 3.5 1.5 1.8 4 4 4 3.5 — — Viscosity at pH 6 18 3.5 275 5.5 5.5 5 — — — Stability at 25°C (weeks) 3 1 1 1 2 2 0 0 0

The molar ratio of oleic acid to calcium chloride in these examples was 2:1.

In sample 8, the emulsifier to fatty acid ratio was 31.4:68.6. This sample was less stable than sample 1, which had an emulsifier to fatty acid ratio of 16.7:83.3.

Examples 10 to 19.

The samples shown in table. 3 were prepared in the same way as those presented in table. 2. Viscosity and stability were measured and analyzed in the same way as described in the previous examples.

Table 3

Component Example 10 eleven 12 13 14 15 16 17 18 19 Oleic acid 7 7 7 7 7 7 7 7 7 7 Stearet-20 0.8 0.8 1.6 0.8 1.4 1 1.6 0.8 0.8 0.8 SLES-3EO 0.8 — — 0.8 0.2 0.6 — 0.8 0.8 0.8 Stearet-2 — — 0.3 — — — — — — — Span 20 — 0.4 — — — — — — — — Twin 80 — 0.4 — — — — — — — — Calcium chloride 1.85 1.85 1.85 2.4 1.85 1.85 1.85 1.85 1.85 2.6 Jaguar S 0.6 0.6 0.6 0.55 0.6 0.6 — 0.5 0.58 0.55 Silica particles — — — — — — 0.7-2.0 — — — Phenoxyethanol 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Glycatyl L 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Water Up to 100 Viscosity at pH 3.5 3 — — 3.65 2.6 3.3 — 1.4 3.5 1.3 Viscosity at pH 6 10.5 — — 5.3 4.2 5.6 — 3.5 9 2.3 Stability at 25°C (weeks) 8 0 0 2 1 1 0 5 5 5

Example 16 included 4 samples with different silica contents: 0.7, 1, 1.4 and 2% by weight. Neither

-9044775 one of these samples did not remain stable for one week. Examples 11 and 12 also showed similar instability.

Viscosity was measured for samples that were stable for at least one week. The most promising of this set was example 10, which remained stable for 8 weeks and whose viscosity increased from 3 to 10.5 Pa.s when moving from pH 3.5 to pH 6.

Examples 20 to 26.

The examples presented in table. 4 were obtained in the same way as the examples from table. 2. Viscosity and stability were measured and analyzed in the same way as described in the previous examples. In addition, additional research was also conducted on these examples (Study 3, details below).

Table 4

Component Example 20 21 22 23 24 25 26 Oleic acid ___ ___ ___ ___ ___ ___ 3.5 Linoleic acid 7 — 7 — 3.5 3.5 — Linolenic acid — 7 — 7 3.5 3.5 3.5 Stearet-20 1.6 1.6 0.8 0.8 1.6 0.8 0.8 SLES-3EO — — 0.8 0.8 — 0.8 0.8 Calcium chloride 1.85 1.85 1.85 1.85 1.85 1.85 1.85 Jaguar S 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Phenoxyethanol 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Glycatyl L 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Water Up to 100 Viscosity at pH 3.5 2 2.3 1.5 1.3 2 3.5 3.3 Viscosity at pH 6 4 3.7 7.8 6 3.7 9 3.6 Stability at 25°C (weeks) 3 3 3 3 1 1 1 P(Pa) value 1072 1224 935 2510 692 567 533

Study 3.

This additional study examined the sweat pore blocking potential of the compositions detailed in Table 1. 4 (and others), using an experiment to clean the capillaries. The equipment used is shown schematically in Fig. 3. The equipment included a pressure control device (1) and a pressure sensor* (2) for compressing the liquid in the tube (3) between them. A capillary (4) extends perpendicularly from the tube (3), tapering to an end section (5) with a diameter of 100 μm. It should be noted that this size is similar to the diameter of the human body's sweat pores (vide supra) (see above).

* Piezoelectric crystal, PX26-OOSGV (0-5 psig range) from OMEGA.

Directly above the end portion (5) there is a microscope lens (6) (not shown), operating in reflected light.

In the first stage, the capillary (4) is filled with artificial sweat, the composition of which is indicated below in Table 5. This is done using a pressure control device (1), the position of which is shown in Fig. 3. At this stage, the pressure regulating device (1) is used to draw artificial sweat into the capillary (4) through the end portion (5).

In the second step, approximately 10 μl of the test composition is drawn into the end portion (5) of the capillary (4), again using the pressure control device (1).

At the third stage, the system is able to reach equilibrium within 15 minutes. During this period and throughout the entire process, the temperature is maintained at 25°C. This period of equilibrium allows for possible interaction of the composition with artificial sweat and possible gelation and blocking of the end portion (5) of the capillary (4).

At the fourth stage, the pressure control device (1) is used to implement small abrupt changes (increases) in internal pressure. Between each jump

- 10 044775 pause to allow constant pressure to be restored. During this process, the presence or absence of any gel plug in the end portion (5) of the capillary (4) is monitored using a microscope. Thus, the pressure will increase until all the gel plugs are pushed out of the end portion (5) of the capillary (4). The pressure (P) required to expel the gel plug is an indication of the strength of the gel formed from artificial sweat and the test composition. This, in turn, is an indicator of the effectiveness of the composition as an antiperspirant.

Table 5

Composition of artificial sweat

Component Quantity (%) Lactic acid 0.0901 Potassium chloride 0.0373 Sodium chloride 0.2098 Ammonium chloride 0.0107 Calcium chloride 0.0222 Urea 0.0018 Bicarbonate of soda* 0.2025 Water Up to 100

* Sodium bicarbonate is added immediately before use, resulting in a pH of 6.9.

The results shown at the bottom of the table. 4 show that each of the compositions created a gel plug upon contact with artificial sweat, and that some of the compositions created gel plugs requiring more than 1 MPa of force to push them out of the end section (5) of the capillary (6).

Some of the samples described previously were also tested using the capillary cleaning method in Study 3. The results are presented in Table 1. 6.

The samples shown in table. 7 were prepared in the same way as those presented in table. 2. Viscosity and stability were measured and analyzed in the same way as described in the previous examples.

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Table 7

Component Example 27 28 29 thirty 31 32 33 34* 35* Oleic acid — — — — — — 7 7 — Linoleic acid — 7 — — — — — — — Linolenic acid 7 — 7 7 7 7 — — 7 Stearet-20 — — 0.8 0.8 — — — 0.8 0.8 SLES-3EO — 0.8 0.8 0.8 1.3 — — 0.8 0.8 Triron X-100 1.6 0.8 — — — — — — — LDAO — — — — 0.3 0.3 0.3 — — SME-C16 — — — — — 1.3 1.3 — — Calcium chloride 1.85 1.85 1.85 1.85 1.85 1.85 1.85 1.85 1.85 Zinc chloride — — — — — — — — — Jaguar S 0.6 0.6 0.3 — 0.6 0.6 0.6 0.6 0.6 PEG 35000 — — 0.3 1 — — — — — Phenoxyethanol 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Glycatyl L 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Water Up to 100 Viscosity at pH 3.5 - - - - - - - 3.5 2.6 Viscosity at pH 6 — — — — — — — 6.8 6.2 Stability at 25°C (weeks) 0 0 0 0 0 0 0 1 1

* In addition to the preparation conditions specified for the previous examples, these examples were prepared using ultrasonic stirring.

Examples 27-33 clearly show that although samples can be prepared using various emulsifiers, they can be difficult to stabilize. Earlier examples (e.g. Example 1, Example 10 and Examples 20-23) have shown that reasonably stable emulsions can be obtained using Jaguar S thickener and simple nonionic emulsifiers such as Steareth-20, or mixtures of a nonionic emulsifier and anionic emulsifier such as like Stearet-20 and SLES-3EO. At the same time, examples 31-33 clearly show that mixtures of a zwitterionic emulsifier (LDAO) and an anionic emulsifier (SLES-3EO or SME-C16) are less successful.

From the examples given in table. 7, only examples 34 and 35 remained stable for 1 week.

The examples presented in table. 8 were obtained in the same way as the examples in table. 2. Viscosity and stability were measured and analyzed as described in the previous examples, and P values were analyzed in accordance with Study Protocol 3.

Table 8

Component Example 36 37 38 39 40 41 42 43 44 Oleic acid — — — 7 7 — — 7 — Linolenic acid — — 7 — — 7 — — 7 Ricinoleic acid 7.6 7.6 — — — — 7.6 — —

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Stearet-20 0.8 0.8 0.8 0.8 0.8 0.8 1.6 1.6 1.6 SLES-3EO 0.8 0.8 0.8 0.8 0.8 0.8 — — — Zinc chloride 1.7 — — — 1.7 1.7 1.7 1.7 1.7 Jaguar S 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Phenoxyethanol 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Glycatyl L 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Water Up to 100 Viscosity at pH 3.5 3 3 2 2.4 3.8 3.5 4 3.2 4 Viscosity at pH 6 13 10.7 15.7 7.3 10 9 225 eleven 9 Stability at 25°C (weeks) 3 1 1 1 3 3 3 2 1 P value (Pa) 850 985 805 780 601 750 1150 960 1025

Example 42 showed a significant increase in viscosity when changing pH from 3.5 to 6. The ability of this sample to reduce sweating in vivo was assessed in Study 4 (see below).

The examples presented in table. 9 were obtained in the same way as the examples in table. 2. Viscosity and stability were measured and analyzed as described in the previous examples, and P values were analyzed in accordance with Study Protocol 3.

The molar ratio of fatty acid to calcium chloride in these examples was 1:1 or less.

Table 9

Component Example 45 46 47 48 49 50 Oleic acid 3.5 3.5 — — — 3.5 Linoleic acid — — 3.5 — — — Linolenic acid — — — 3.5 — — Ricinoleic acid — — — — 3.5 — Stearet-20 1.6 0.8 0.8 0.8 1.6 1.6 SLES-3EO — 0.8 0.8 0.8 — — Calcium chloride 1.85 1.85 1.85 1.85 — — Zinc chloride — — — — 1.7 1.7 Jaguar S 0.6 0.6 0.6 0.6 0.6 0.6 PEG 35000 — — — — — — Phenoxyethanol 0.5 0.5 0.5 0.5 0.5 0.5 Glycatyl L 0.05 0.05 0.05 0.05 0.05 0.05 Water Up to 100 Viscosity at pH 3.5 1.4 0.5 1 0.5 3.8 1.2 Viscosity at pH 6 2.2 1.1 16.8 7.9 45 425 Stability at 25°C (weeks) 3 3 3 3 3 3 P value (Pa) 550 1070 601 642 625 615

The examples presented in table. 10-12 were prepared by the method described below. Viscosity and stability were measured and analyzed in the same way as described in the previous examples.

To prepare the samples, the emulsifier(s) were dissolved in water with stirring and heating to 70°C. The resulting solution was allowed to cool to room temperature and then the thickener was added using a Silverson L4RT homogenizer for 10 minutes at 5000 rpm. The fatty acid was then added dropwise using a homogenizer for 10 min at 7500 rpm. Then the water-soluble metal salt was added using a homogenizer for 3 minutes at 7500 rpm. Finally, preservatives were added using a homogenizer for 2 min at 7500 rpm. The components and quantities used are indicated in the tables.

Table 10

Component Example 51 52 53 54 55 56 57 58 Oleic acid 7 7 7 7 7 7 7 7 Stearet-20 — ... ... 0.8 ... 0.8 0.8 — PG-3-S — — — 1 2 2 — 1 PG-6-DS 1 — — — — — 1 1 PG-10-S — 1 1 — — — — — PG-1O-0 — ... 1 ... ... ... ... ... PG-10-CC 1 1 — — — — — — Calcium chloride 1.85 1.85 1.85 1.85 1.85 1.85 1.85 1.85 Jaguar S 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Phenoxyethanol 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Glycatyl L 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Water Up to 100 Viscosity (pH 3.5) 3 2.7 3.2 3.2 0.6 0.8 3.5 4.8 Viscosity (pH 6) 2.8 3 z, z 7 8.8 2.4 4.9 9.3 Stability at 25°C (weeks) 2 2 2 2 2 2 2 2

Each example in the table. 10 contained a polyglyceryl emulsifier and was stable for 2 weeks at 25°C. In addition, each of them showed an increase in viscosity when changing pH from 3.5 to 6.

The examples given in table. 11 also contained a polyglyceryl emulsifier, and each had acceptable stability at 25°C. In addition, each of them showed an increase in viscosity when changing pH from 3.5 to 6. Example 59 showed a particularly high increase in viscosity when changing pH from 3.5 to 6.

Table 11

Component Example 59 60 61 62 63 64 65 66 Oleic acid 7 7 7 7 — — — — Ricinoleic acid — — — 7.6 7.6 7.6 7.6 Stearet-20 — — — 0.8 — 0.8 — — PG-3-S 2 — — 1 — 1 — — PG-6-DS 2 1 — — — — 1 — PG-10-S — — 1 — 1 — — 1 PG-1O-0 — — — — — — — 1 PG-10-CC — 1 1 — 1 — 1 — Zinc chloride 1.7 1.7 1.7 1.7 1.7 1.7 1.7 1.7 Jaguar S 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 Phenoxyethanol 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Glycatyl L 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Water Up to 100 Viscosity (pH 3.5) 5 4 3.5 3.1 2.2 3.6 2.6 3.9 Viscosity (pH 6) 115 26 36 17 9 11.6 18 31 Stability at 25°C (weeks) 4 2 2 1 2 2 1 2

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Examples in table. 12 also contained a polyglyceryl emulsifier, and each had acceptable to good stability at 25°C. Samples 68 and 70 showed particularly good stability.

Many examples given in table. 12 also showed a particularly significant increase in viscosity when changing pH from 3.5 to 6. Examples 67-70 and 73-74 are notable in this regard.

______________________________________________________________Table 12

Component Example 67 68 69 70 71 72 73 74 75 76 Oleic acid 7 — 7 7 7 7 7 7 — 7 Ricinoleic acid — 7.6 — — — — — — 7.6 — PG-3-S — 1 1 2 1 3 1 3 1 2 PG-6-DS — 1 1 2 3 1 3 1 1 2 PG-10-S 1 — — — — — — — — — PG-1O-0 1 — — — — — — — — — PG-10-CC 1 — — — — — — — — — Calcium chloride — — — — 1.85 1.85 — — — — Zinc chloride 1.7 1.7 1.7 1.7 — — 1.7 1.7 1.7 1.7 Jaguar S 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 — — Phenoxyethanol 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Glycatyl L 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Water Up to 100 Viscosity (pH 3.5) 1.6 74 4.3 15 17 7.6 15 6.6 — — Viscosity (pH 6) 120 223 274 393 57 10 211 283 — — Stability at 25°C (weeks) 3 6 3 5 3 3 3 2 1 1

Study 4.

Substantially the same Example* as Example 1 and Example 42 was tested in vivo for effectiveness in reducing sweating.

* Prepared in the same way, but contains 8% oleic acid and 1% less water. Referred to here as Example 1A.

The method used was the sauna spin protocol (published by Brandt, Bielfeldt, Springmann & Wilhelm, Influence of climatic conditions on antiperspirant efficacy determined at different test areas, Skin Research and Technology, 2018, 14: 213-219), which is a reliably proven mass an in vivo study to evaluate the effectiveness of antiperspirants. In such studies, 16 test areas are marked on the back of ordinary sauna visitors to compare 8 products with 8 control areas located opposite them. Application of the product is repeated for 4 consecutive days, and on the 5th day a gravimetric assessment of sauna-induced sweating is carried out.

Sixteen test sites (size: 4x5 cm) are marked with a permanent pen (8 test sites on each side of the spine). Two test fields, mirrored to the right and left of the spine, are considered a pair and used to compare the test product and the untreated control region. The treated and untreated sides of the back were alternated between subjects. In this case, test areas were selected by cyclic permutation.

From days 1 to 4, each of the 8 test products is applied to its test area and distributed evenly over it (dosage: 75 µl). After application, subjects rest for approximately 5 minutes to allow the test products to be absorbed into the skin. Sealed, non-absorbent patches are then applied to all test and control areas. Subjects then leave the testing center and return 2 h (±5 min) later to remove the patches.

On day 5, subjects' backs are washed with water and dried with a paper towel. All test areas, as well as adjacent untreated areas, are covered with pre-weighed absorbent film pads (attached to the back using Fixomull®). Subjects then lie on their stomachs in a sauna at a temperature of approximately 80°C for approximately 15 minutes. Immediately after leaving the sauna, all pads are removed with tweezers and placed in cups. Gravimetric measurements of gaskets are carried out immediately.

The above method was used to independently test the in vivo sweat reduction effectiveness of Example 1A and Example 42.

Example 1A involved 25 women and all 25 passed the test. Example 1A was found to cause a 9% greater reduction in sweat mass (SMB) compared to the untreated control site, which was significant at the 95% level.

In the evaluation of Example 42, 25 women were recruited, 24 of whom completed the trial. Example 42 was found to cause 29% more SMP compared to the untreated control site, which was significant at the 99% level.

Claims (12)

1. Oil in water emulsion containing: (i) liquid C ₁₀ -C ₂₂ fatty acid; (ii) an emulsifier for said C ₁₀ -C ₂₂ fatty acid; (iii) a water-soluble metal salt capable of forming a water-insoluble salt with said C ₁₀ -C ₂₂ fatty acid at a pH greater than 6; and (iv) water. 2. An emulsion according to claim 1, characterized in that said fatty acid is unsaturated and preferably contains 18 carbon atoms. 3. The emulsion according to claim 2, characterized in that said fatty acid is selected from oleic, linoleic, linolenic and ricinoleic acids. 4. The emulsion according to claim 3, characterized in that said fatty acid is selected from oleic acid and ricinoleic acid. 5. Emulsion according to any one of claims 1-4, characterized in that the water-soluble metal salt is polyvalent. 6. The emulsion according to claim 5, characterized in that the water-soluble metal salt is selected from calcium or zinc salt. 7. Emulsion according to any one of claims 1-6, additionally containing a thickener. 8. Emulsion according to claim 7, characterized in that the thickener is a cationic or nonionic polymer. 9. The emulsion according to claim 8, characterized in that the thickener is selected from guar gum and its derivatives and cellulose derivatives. 10. A method for reducing sweating, including local application of an emulsion according to any one of claims 1 to 9. 11. The method according to claim 10, characterized in that the pH of the emulsion is increased by at least 1 unit upon application, which leads to the formation of a gel from said soluble metal salt and fatty acid. 12. An antiperspirant product containing an oil in water emulsion according to any one of claims 1 to 9, packaged in a roll-on dispenser.