FR3118703A1 - EMULSION STICK WITH MAGNESIUM ACTIVE FOR ANTI-ODOR EFFECTIVENESS - Google Patents

Abstract

EMULSION STICK WITH MAGNESIUM ACTIVE ACTIVES FOR ANTI-ODOR EFFECTIVENESS A stable deodorant emulsion stick is provided. The stick includes a magnesium salt, surfactant, oil, wax, filler and water. The stick is free of aluminum salt and includes an inverted emulsion. There is also a method of treating body odor with the stable deodorant stick. Figure for abstract: NIL

Description

EMULSION STICK WITH MAGNESIUM ACTIVE FOR ANTI-ODOR EFFECTIVENESS

FIELD OF THE INVENTION

The invention relates to stable deodorant emulsion sticks comprising a magnesium salt and uses thereof.

background of the invention

Body odor is caused by the breakdown of sweat by bacteria. Currently, body odor can be treated using aluminum salts, which act on odor as an active bactericide and reduce sweat as an antiperspirant. The fight against odors is essential for the profession of personal hygiene. Other anti-odor actives are also available on the market, such as zinc gluconate, and technologies such as glycolic sticks, however, they do not reach the level of effectiveness of aluminum salts.

Deodorant products are available in the form of solid emulsion compositions such as water-in-oil emulsion (also called inverse emulsion) for topical application to the skin of, for example, an armpit. It is often difficult to obtain emulsion deodorant sticks with desirable mechanical properties, for example sufficient hardness and sufficient deposit during application.

Even though there is no approved scientific evidence that aluminum salts are harmful to health, they have a "bad" reputation. Other effective deodorant active substances have been explored. Magnesium salts, such as magnesium oxide and magnesium hydroxide, have been shown to have the same level of odor control effectiveness as aluminum salts in aerosols. Magnesium oxide and magnesium hydroxide are however very difficult to stabilize in a deodorant emulsion stick with desirable mechanical properties.

There thus remains a need for stable, well-dispersed, hard and integrated deodorant emulsion sticks comprising a magnesium salt instead of, for example, an aluminum salt.

The present invention relates to stable deodorant emulsion sticks comprising a magnesium salt and uses thereof. The inventors have unexpectedly discovered that stable anhydrous deodorant sticks have a good sensory profile, improved stability, high dispersion, optimal hardness, excellent payload, and statistically superior anti-odor efficacy.

A stable deodorant emulsion stick is provided. The stick comprises about 1 to 6% by weight of a magnesium salt selected from the group consisting of magnesium oxide, magnesium hydroxide and a combination thereof, about 0.5 to 4% by weight of a surfactant selected from the group consisting of PEG/PPG-18/18 dimethicone, cetyl PEG/PPG-10/1 dimethicone, polyglyceryl-3 diisostearate and a combination thereof, about 14 to 17% by weight of an oil selected from the group consisting of isopropyl palmitate, dimethicone and a combination thereof, about 8 to 10% by weight of a wax, a filler and water. The stick is free of aluminum salt and includes an inverse emulsion.

The stick may include about 2-3% by weight magnesium salt.

The surfactant can be a combination of PEG/PPG-18/18 dimethicone, cetyl PEG/PPG-10/1 dimethicone and polyglyceryl-3 diisostearate. The stick may include about 0.2 to 1% by weight PEG/PPG-18/18 dimethicone, about 0.5 to 2.5% by weight cetyl PEG/PPG-10/1 dimethicone, about 0.2 to 0.4% by weight polyglyceryl-3 diisostearate, or a combination thereof.

The oil can be a combination of isopropyl palmitate and dimethicone. The stick may include about 8-10% by weight isopropyl palmitate, about 6-7% by weight dimethicone, or a combination thereof.

The wax can be polyethylene.

The stick may further comprise a preservative selected from the group consisting of phenoxyethanol, pentylene glycol and a combination thereof.

The stick may be free of beheneth-10, perfume, or a combination thereof. The stick may be free of clay. The stick can have a pH no higher than 10.

A method of treating body odor on the skin is also provided. The method includes applying the stable deodorant stick to the skin in an amount effective to provide an anti-odor effect to the skin.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides stable deodorant emulsion sticks comprising a magnesium salt and uses thereof. Magnesium salts such as magnesium oxide and magnesium hydroxide come in powder form. Adding magnesium oxide to a deodorant emulsion stick formula has been shown to break the structure of the emulsion. Surprisingly, the inventors have discovered a balance of surfactants to make stable, well-dispersed, hard, and integrated deodorant sticks that include an inverse emulsion. The resulting emulsion deodorant sticks with magnesium salts show good properties such as sensory profile, hardness, payload and anti-odor efficacy like glycolic deodorant sticks with an aluminum salt. Unless otherwise stated, all weight percentages given herein are relative to the total weight of a composition, formula or deodorant stick.

Unless otherwise indicated, the percentage by weight of an ingredient of a composition is expressed relative to the total weight of the composition.

The term “antiperspirant” used here refers to a cosmetic composition comprising ingredients which control perspiration and therefore body odor. An antiperspirant can prevent sweat from reaching the skin's surface and reduce bacteria that cause body odor. An antiperspirant is applied to the skin, such as an armpit, to reduce or prevent the formation of sweat on the skin. An antiperspirant can come in the form of a stick, an aerosol (or spray), a roll-on deodorant, a wipe or a cream.

The term "deodorant" as used herein refers to a cosmetic composition comprising ingredients that control body odor caused by bacteria breaking down sweat, but not perspiration. A deodorant can inhibit the growth of bacteria or kill bacteria and thus reduce or prevent body odor. Among the various active ingredients in deodorants, aluminum salts are commonly used and most effective bactericides. A deodorant can come in the form of a stick, an aerosol (or spray), a roll-on deodorant, a wipe or a cream.

The terms “odor control effectiveness” and “deodorant effectiveness” are used interchangeably herein and refer to the effectiveness of a deodorant in controlling body odor caused by bacteria breaking down sweat.

The term "stable" as used herein refers to a physical or chemical property of a cosmetic composition such as an anhydrous deodorant stick that does not change significantly over time. For example, no significant amount of precipitation, color change, or exudation of an oil (e.g., less than about 10, 5, 1, 0.5, or 0.1% by weight) is observed. in an anhydrous deodorant stick for a predetermined period of time, for example, for about 1, 3, 6, 12, 18 or 24 months.

An emulsion is a mixture of two liquids that are normally immiscible (immixable or non-mixable). An emulsion can be direct (i.e. oil dispersed in water, o/w), inverse (i.e. water dispersed in oil, w/o) or bicontinuous. One or more surfactants can be used to promote the formation of an emulsion in a formula. A direct surfactant promotes the formation of a direct emulsion. Examples of direct surfactants include beheneth-10. An invert surfactant promotes the formation of an invert emulsion in a formula. Examples of inverted surfactants include PEG/PPG-18/18 dimethicone, cetyl PEG/PPG-10/1 dimethicone and polyglyceryl-3 diisostearate. The emulsion structure in a formula can be observed under a microscope or determined in a droplet test. In the droplet test, the conductivity of the formula is determined. A formula having little or no conductivity and/or interaction with water includes an inverse emulsion.

A stable deodorant emulsion stick is provided. The stick includes magnesium salt, surfactant, oil, wax, filler and water. The stick is free of an aluminum salt and includes an inverse emulsion.

The stick may include the magnesium salt at a concentration of about 1-6% by weight or about 2-3% by weight. The magnesium salt can be selected from the group consisting of magnesium oxide, magnesium hydroxide and a combination thereof. The magnesium salt may be magnesium oxide. The stick may include about 2-3% by weight magnesium oxide.

The surfactant can be any cosmetically acceptable compound suitable for lowering the surface tension (or interfacial tension) between two liquids, between a gas and a liquid, or between a liquid and a solid. Surfactants can act as detergents, wetting agents, emulsifiers, foaming agents and dispersants. The surfactant can be effective in maintaining the inverse emulsion in the stick. The surfactant can be selected from the group consisting of PEG/PPG-18/18 dimethicone, cetyl PEG/PPG-10/1 dimethicone, polyglyceryl-3 diisostearate and a combination thereof. The stick may include about 0.5 to 4% by weight surfactant. The surfactant can be PEG/PPG-18/18 dimethicone, cetyl PEG/PPG-10/1 dimethicone, polyglyceryl-3 diisostearate or a combination thereof. The stick may include about 0.2 to 1% by weight PEG/PPG-18/18 dimethicone, about 0.5 to 2.5% by weight cetyl PEG/PPG-10/1 dimethicone, about 0.2 to 0.4% by weight polyglyceryl-3 diisostearate, or a combination thereof.

The stick may be free of direct surfactant. The direct surfactant may be beheneth-10. The stick may be beheneth-10 free.

The oil may be any cosmetically acceptable fatty substance suitable for providing emollience to the stick and effective in maintaining the same or similar amount of deposit on the stick when applied, despite the hardness of the stick. The oil can be liquid at ambient temperature (25° C.) and at atmospheric pressure (760 mmHg, that is to say 10 ⁵ Pa). The oil can be mineral oil, animal oil, vegetable oil, synthetic oil or a combination thereof. The oil can be selected from silicones such as D5, dimethine, vegetable oils, petroleum-based oils such as petrolatum, esters, or combinations thereof. The oil can be selected from the group consisting of isopropyl palmitate, dimethicone and a combination thereof. The stick may include about 14-17% by weight oil. The oil can be isopropyl palmitate, dimethicone or a combination thereof. The stick may include about 8-10% by weight isopropyl palmitate, about 6-7% by weight dimethicone, or a combination thereof.

The wax can be any cosmetically acceptable polymer suitable as a structuring agent responsible for the hardness of the stick. The wax can be chosen from animal, fossil, vegetable, mineral and synthetic waxes. For example, the wax can be chosen from vegetable waxes, fatty alcohols, paraffin waxes or combinations thereof. The stick may include about 8 to 10% by weight wax. The wax can be polyethylene.

The filler can be any cosmetically acceptable compound suitable for increasing the bulk, weight, viscosity, opacity or strength of the stick. The filler may be solid at ambient temperature (25° C.) and at atmospheric pressure (760 mmHg, that is to say 10 ⁵ Pa). The stick may comprise about 0.1 to 0.3% by weight of the filler. The filler may be pearlite.

The stick may be fragrance-free. The presence of a fragrance can cause a color change in the stick.

The stick of the present invention may comprise no more than about 70% by weight water, may be free of clay, and/or may have a pH no greater than about 10, for example, about 4 to 10.5 at 9 or 6 at 8.

The aluminum salt-free stable deodorant emulsion stick of the present invention can be prepared without precipitation. Oils and surfactants can be mixed with agitation in a range of about 500 rpm to about 900 rpm (eg, about 700 rpm for about 10 minutes) to form a mixture. The mixture can be heated to a temperature in a range of about 50°C to about 70°C (eg, about 60°C) with stirring in a range of about 800 rpm to about 1200 rpm (eg, about 1000 rpm) for about 5 to 20 minutes (eg, about 10 minutes) to form a first invert emulsion. A filler (eg, perlite) may be added to the first inverted emulsion at a temperature in a range of about 60°C to about 80°C (eg, about 70°C) with agitation in a range from about 800 rpm to about 1200 rpm (eg, about 1000 rpm) to form a second inverted emulsion. A wax can be added and melted into the second inverted emulsion at a temperature in a range of about 80°C to about 99°C (eg, about 90°C) with agitation in a range of about 500 rpm/ min at about 700 rpm (eg, about 600 rpm) to form a third inverted emulsion. The magnesium salt can be added and dispersed in the third invert emulsion to form a deodorant invert emulsion. The deodorant invert emulsion can be heated, for example, to about 100°C before being used to make the stable deodorant emulsion stick. The stick can be stored without precipitation at about 1 to 5°C, for example, about 4°C.

A method for preparing a stable deodorant emulsion stick free of aluminum salt is also provided. The stick includes an invert emulsion. The composition includes magnesium salt, surfactant, wax, oil, filler and water. The magnesium salt is selected from the group consisting of magnesium oxide, magnesium hydroxide and a combination thereof. The surfactant may be present in an amount effective to maintain the inverted emulsion. The method includes (a) mixing water, oil and surfactant with agitation in a range of about 500 rpm to about 900 rpm to form a mixture, (b ) heating the mixture to a first temperature in a range of about 50°C to about 70°C with stirring in a range of about 800 rpm to about 1200 rpm for about 5 to 20 minutes, which which forms a first invert emulsion, (c) adding the filler to the first invert emulsion at a second temperature in a range of about 60°C to about 80°C with agitation in a range of about 800 rpm/ min at about 1200 rpm, thereby forming a second invert emulsion, (d) adding and melting the wax into the second invert emulsion at a third temperature within a range of about 80°C to about 99°C with agitation in a range of about 500 rpm to about 700 rpm to form a third inverted emulsion, (e) adding and dispersing the magnesium salt in the third invert emulsion, thereby forming a deodorant invert emulsion, (f) heating the deodorant invert emulsion, and (g) using the deodorant invert emulsion after heating to make the stable deodorant emulsion stick. The method may further include storing the stick without precipitation at a temperature within a range of about 1°C to about 10°C.

A method of treating body odor on the skin is also provided. The method of treatment includes applying the stable deodorant stick of the present invention to the skin in an amount effective to provide an anti-odor effect to the skin. The anti-odor effect can last at least about 8, 16, 24, 48 or 72 hours.

Example 1. Preparation of deodorant emulsion sticks e

Aluminum salt-free deodorant emulsion sticks were prepared. Water, oils (eg, isopropyl palmitate and dimethicone) and surfactants (eg, PEG/PPG-18/18 dimethicone, cetyl PEG/PPG-10/1 dimethicone, polyglyceryl-3 diisostearate and / or beheneth-10) were added to a ^THERMOMIX® mixer and mixed with stirring at 700 rpm for 10 minutes. The temperature was increased to 60°C and the mixture was stirred for 10 minutes at 1000 rpm. The emulsion reversed and the mass became thicker. Then the temperature was further increased to 70°C with the same stirring and perlite was added. Wax (e.g. polyethylene) was added to the formula and the temperature raised to 90°C to melt for 10 minutes with 600 rpm stirring. Preservatives (i.e. phenoxyethanol and pentylene glycol) have been added. Finally, a magnesium salt (ie magnesium oxide) was added and dispersed for 10 minutes to obtain a deodorant emulsion formula. The deodorant formula was heated to 100°C before being poured to make deodorant emulsion sticks. Table 1 shows the concentration (% by weight) of each ingredient in deodorant emulsion sticks A, B, C and D. The deodorant emulsion sticks were then immediately stored in a refrigerator or cooling tunnel at 4 °C to avoid the precipitation of the magnesium salt.

Deodorant emulsion sticks

type of cosmetic Ingredients AT B VS D Active compound magnesium oxide 3 2 2 2 surfactant Cetyl PEG/PPG-10/1 dimethicone 2 2 2 1 Surfactant Dimethicone (and) PEG/PPG-18/18 dimethicone 0.96 0.96 0.96 0.3 surfactant Polyglyceryl-3 diisostearate 0.3 0.3 0.3 0.3 surfactant Beheneth-10 0 0 0 2 Oil Isopropyl Palmitate 9 9 9 9 Oil Dimethicone 6.24 6.24 6.24 6.94 Wax Polyethylene 9 9 9 9 Charge Perlite 0.2 0.2 0.2 0.2 Conservative Phenoxyethanol 0.5 0.5 0.5 0.5 Conservative Pentylene Glycol 0.5 0.5 0.5 0.5 Scent Scent 0 1.4 1.4 1.4 Solvent Water 68.3 67.9 67.9 66.86

Example 2. Characteristics of sticks of deodorant emulsion

Compared to glycolic deodorant sticks with an aluminum salt as a reference, deodorant emulsion sticks A, B and C, but not deodorant emulsion stick D, showed a good sensory profile, improved stability, dispersion, optimal hardness, payload, freshness and statistically superior anti-odor effectiveness.

The deodorant emulsion sticks were tested in a droplet test to determine if they included an invert emulsion. Deodorant Emulsion Sticks A, B, and C showed low conductivity and did not interact with water, indicating the presence of an inverted emulsion in Deodorant Emulsion Sticks A, B, and C. Deodorant Emulsion Stick D showed high conductivity and interacted with water, indicating the absence of an inverted emulsion in Deodorant Emulsion Stick D.

In a sensory test, deodorant emulsion sticks A, B and C showed a sensory profile similar to the reference.

When tested for hardness using a texturometer, deodorant emulsion sticks A, B and C showed similar characteristics to the reference.

In a payload test, deodorant emulsion sticks A, B and C showed similar characteristics to the reference.

In the anti-odor tests, the deodorant emulsion sticks A, B and C showed statistically superior efficacy to that of the reference.

Deodorant Emulsion Stick A was stable and no precipitation was observed for at least 6 months. Deodorant emulsion sticks B and C showed a change in color and this instability was due to the perfume contained in the sticks.

The term "about", as used herein in reference to a measurable value such as quantity, percentage and the like, is meant to encompass variations of ±20% or ±10%, more preferably ±5%, even more preferably ±1%, and even more preferably ±0.1% of the specified value, since such variations are appropriate.

Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. On the contrary, various modifications may be made in detail within the scope and range of equivalents of the claims without departing from the invention.

Claims (10)

Stable deodorant emulsion stick, comprising:
(a) 1 to 6% by weight of a magnesium salt selected from the group consisting of magnesium oxide, magnesium hydroxide and a combination thereof;
(b) 0.5 to 4% by weight of a surfactant selected from the group consisting of PEG/PPG-18/18 dimethicone, cetyl PEG/PPG-10/1 dimethicone, polyglyceryl-3 diisostearate and a combination of these;
(c) 14 to 17% by weight of an oil selected from the group consisting of isopropyl palmitate, dimethicone and a combination thereof;
(d) 8 to 10% by weight of a wax;
(e) a filler; And
(f) water;
wherein the stick is free of an aluminum salt and includes an inverse emulsion. Stick according to claim 1, comprising from 2 to 3% by weight of magnesium salt. A stick according to claim 1 or 2, wherein the surfactant is a combination of PEG/PPG-18/18 dimethicone, cetyl PEG/PPG-10/1 dimethicone and polyglyceryl-3 diisostearate. A stick according to claim 3, comprising 0.2 to 1% by weight of the PEG/PPG-18/18 dimethicone. A stick according to claim 3, comprising 0.5 to 2.5% by weight of the cetyl PEG/PPG-10/1 dimethicone. A stick according to claim 3, comprising 0.2 to 0.4% by weight of polyglyceryl-3 diisostearate. A stick according to any of claims 1 to 6, wherein the oil is a combination of isopropyl palmitate and dimethicone. A stick according to claim 7, comprising 8 to 10% by weight of isopropyl palmitate. A stick according to claim 7, comprising 6 to 7% by weight of dimethicone. Stick according to any one of claims 1 to 9, in which the wax is polyethylene.