WO2018122311A1

WO2018122311A1 - Cosmetic process for preventing and/or treating perspiration and optionally body odor

Info

Publication number: WO2018122311A1
Application number: PCT/EP2017/084717
Authority: WO
Inventors: Jean-Baptiste Galey; Mireille Arnaud-Roux; Ségolène ADAM DE BEAUMAIS
Original assignee: L'oreal
Priority date: 2016-12-30
Filing date: 2017-12-28
Publication date: 2018-07-05
Also published as: FR3061430A1; FR3061430B1

Abstract

The present invention relates to a cosmetic process for preventing and/or treating perspiration and optionally the body odor associated with human perspiration, characterized in that it comprises at least the placing in contact of a keratin material and more particularly the skin with a composition (C1) whose pH is greater than or equal to 6.5 and less than 8 and comprising an effective amount of at least one colloidal dispersion of anionic silica particles, said composition (C1) being constituted extemporaneously by mixing: a first composition (B1) containing a sol of said anionic silica particles at a pH of greater than or equal to 8 and less than 11, preferably greater than or equal to 8.5 and less than 11, more preferentially greater than or equal to 9 and less than 11, and a second composition (B2), which is different from composition (B1), and which contains an effective amount of at least one acid to adjust the pH of said mixture (C1) to a value of greater than or equal to 6.5 and less than 8.

Description

Cosmetic process for preventing and/or treating perspiration and optionally body odor

The present invention relates to compositions, especially cosmetic compositions, preferably antiperspirant and optionally deodorant compositions. More particularly, the invention relates to the field of caring for and cleansing the skin, in particular bodily skin. The present invention also relates to a process for the cosmetic treatment of the skin, and also to a cosmetic process for treating perspiration and optionally the body odor associated with human perspiration, especially underarm odor and foot odor.

The armpits and also certain other parts of the body are generally the site of much discomfort that may arise directly or indirectly from perspiration. This perspiration often leads to unpleasant and disagreeable sensations that are mainly due to the presence of sweat resulting from perspiration, which may, in certain cases, make the skin clammy and clothing wet, especially in the region of the armpits or of the back, thus leaving visible marks. Moreover, the presence of sweat may give rise to the production of body odor, which is generally unpleasant. Finally, during its evaporation, sweat may also leave salts and/or proteins on the surface of the skin, which may result in whitish marks on clothing. Such discomfort should not be disregarded, even in the case of moderate perspiration.

In the cosmetics field, it is thus well known to use, in topical application, antiperspirant products containing substances that have the effect of limiting or even preventing the flow of sweat in order to overcome the problems mentioned above. These products are generally available in the form of roll-ons, sticks, aerosols or sprays.

Antiperspirant substances generally consist of aluminum salts, such as aluminum chlorohydrate and aluminum hydroxyhalides, or of complexes of aluminum and zirconium. These substances make it possible to reduce the flow of sweat by forming a plug in the sweat duct.

However, in the case of certain users, repeated application of these substances may lead to discomfort.

These antiperspirant substances may also leave marks during their application or after application, which has the consequence of occasionally giving rise to unesthetic marks on the application areas and/or of staining clothing that is in contact with the application area. There is thus an ongoing need to identify novel methods for treating perspiration which do not have the set of drawbacks described above.

The object of the present invention is, precisely, to meet these expectations. The invention is directed more particularly toward proposing a treatment method not requiring the use of aluminum salts and which proves to be just as efficient or even more efficient for limiting the flow of sweat.

Thus, one subject of the invention is a cosmetic process for preventing and/or treating perspiration and optionally the body odor associated with human perspiration, characterized in that it comprises at least the placing in contact of a keratin material, in particular of the skin and more particularly of one or more target areas of the skin and especially the underarm areas, with a composition (CI) whose pH is greater than or equal to 6.5 and less than 8 and comprising an effective amount of at least one colloidal dispersion of anionic silica particles, said composition (CI) being constituted extemporaneously by mixing:

- a first composition (Bl) containing a sol of said anionic silica particles at a pH of greater than or equal to 8 and less than 11, preferably greater than or equal to 8.5 and less than 11 , more preferentially greater than or equal to 9 and less than 11 , and

- a second composition (B2), which is different from composition (Bl), and which contains an effective amount of at least one acid to adjust the pH of said mixture (CI) to a value of greater than or equal to 6.5 and less than 8.

Surprisingly, the inventors have in fact discovered that the application of said composition (CI) makes it possible to block sweat pores and thus to efficiently limit the flow of sweat over time.

More precisely, the inventors have discovered that it is possible to generate a form of colloidal silica that is efficient in composition (CI) starting with the colloidal silica sol of composition (Bl) corresponding to a stabilized form of anionic silica particles and whose pH is greater than or equal to 8 and less than 11 , preferably greater than or equal to 8.5 and less than 11, more preferentially greater than or equal to 9 and less than 11 , provided that the pH of this anionic silica particle sol is adjusted to a pH value of greater than or equal to 6.5 and less than 8, in particular ranging from 6.6 to 7.8, more preferentially ranging from 6.8 to 7.5, even more preferentially to a pH of about 7, such as 7 ± 0.1 and in particular 7, by mixing said composition (Bl) with composition (B2) before application to the keratin material and in particular to the target areas of the skin.

Thus, the pH of composition (CI) is greater than or equal to 6.5 and less than 8, and ranges in particular from 6.5 to 7.8, more preferentially from 6.8 to 7.5; even more preferentially, the pH of (CI) is about 7, such as 7 ± 0.1 and in particular is 7.

This pH modification has the effect of generating a metastable state of the anionic silica particles, which then prove to be capable of forming a plug in the sweat ducts.

To do this, the process according to the invention uses at least two compositions (Bl) and (B2), which are isolated from each other, a first composition (Bl) conveying an anionic colloidal silica sol at a pH of greater than or equal to 8 and less than 11, preferably greater than or equal to 8.5 and less than 11, more preferentially greater than or equal to 9 and less than 11 , this anionic form corresponding to the stabilized form of the colloidal silica particles, and a second composition (B2) containing at least one acid intended precisely for adjusting the pH of the first composition after mixing (Bl) with (B2) to a value of less than 8, to generate the effective colloidal silica form of composition (CI).

According to a particular embodiment, composition (CI) is formed on contact with the keratin material by sequential application of said compositions (Bl) and (B2).

According to another embodiment, composition (CI) is formed on contact with the keratin material by simultaneous application of said compositions (Bl) and (B2). This variant may especially be performed using a device which individually stores compositions

(Bl) and (B2) and which is equipped with an applicator designed to allow simultaneous dispensing of the two compositions.

According to yet another embodiment, composition (CI) is formed prior to its application to said keratin material, by extemporaneous mixing of all or part of the first composition (Bl) with all or part of the second composition (B2).

In particular, composition (CI) may be obtained on conclusion of mixing of

(B1)+(B2) for a time of between 0.1 second and 1 hour, more particularly between 0.1 second and 45 minutes and preferentially between 1 second and 10 minutes, and then applied to a keratin material, more particularly the skin and even more particularly one or more target areas of the skin. For the purposes of the present invention, the term "anionic colloidal silica sol" means a stable dispersion or suspension of anionic silica particles as defined below.

The terms "anionic silica sol", "stabilized form of the colloidal silica particles", "silica particle sol", "colloidal silica particle sol" and "anionic silica particle sol" are equivalent for the purposes of the present invention.

This "sol" has the property of being transformed into a gel following the modification of its physicochemical environment, for instance a modification of the pH.

Composition (Bl) contains an anionic silica particle sol at a pH of greater than or equal to 8 and less than 11, preferably greater than or equal to 8.5 and less than 1 1, more preferentially greater than or equal to 9 and less than 11 , in particular greater than or equal to 10 and the less than 11. This composition (Bl) may also contain additional non-acidic compounds intended to modify the texture and/or appearance and/or odor thereof. According to a particular form of the invention, composition (Bl) does not contain any additional compounds intended to modify the texture thereof.

Composition (B2) contains an effective amount of at least one acid to adjust the pH of the mixture of compositions (Bl) and (B2) to a value of greater than or equal to 6.5 and less than 8. This composition (B2) may also contain additional non-acidic compounds intended to modify the texture and/or appearance and/or odor thereof.

As stated above, this second composition (B2) is intended to convey at least one acidic compound in an amount sufficient to adjust the pH after mixing with composition (Bl), said mixture conditioning the generation of the effective form of anionic silica particles.

Another subject of the invention is a treatment process, especially a cosmetic process and thus a non-therapeutic process, for keratin materials, preferentially for the skin, more preferentially one or more target areas of the skin, comprising the application to said keratin materials of a composition (CI) constituted extemporaneously by mixing:

- a first composition (Bl) containing an anionic silica particle sol at a pH of greater than or equal to 8 and less than 1 1, preferably greater than or equal to 8.5 and less than 11, more preferentially greater than or equal to 9 and less than 11 , and - a second composition (B2), which is different from composition (Bl), and which contains an effective amount of at least one acid to adjust the pH of the mixture of (Bl) and (B2) to a value of greater than or equal to 6.5 and less than 8. According to another particular embodiment of the invention, the process is a cosmetic process for preventing and/or treating perspiration and optionally the body odor associated with human perspiration, in which keratin materials, more particularly the skin and even more particularly one or more target areas of the skin are treated:

- with a composition (Bl) comprising an anionic silica particle sol at a pH of greater than or equal to 8 and less than 11, preferably greater than or equal to 8.5 and less than 11 , more preferentially greater than or equal to 9 and less than 11 , and then

- with a composition (B2), which is different from composition (Bl), and which contains an effective amount of at least one acid to adjust the pH of the mixture of (Bl) and (B2) to a value of greater than or equal to 6.5 and less than 8,

in which the pH of the mixture of (Bl) and (B2) has a value of greater than or equal to 6.5 and less than 8, and

the time separating the application of composition (Bl) from the application of composition (B2) is set at a duration of between 0.1 second and 1 hour, preferentially between 0.1 second and 30 minutes and more particularly between 0.1 second and 10 minutes.

According to another particular embodiment of the invention, the process is a cosmetic process for preventing and/or treating perspiration and optionally the body odor associated with human perspiration, in which keratin materials, more particularly the skin and even more particularly one or more target areas of the skin are treated:

- with a composition (B2), containing an effective amount of at least one acid to adjust the pH of the mixture of (Bl + B2) to a value of greater than or equal to 6.5 and less than 8, and then

- with a composition (Bl), which is different from composition (B2) and which comprises an anionic silica particle sol at a pH of greater than or equal to 8 and less than 11, preferably greater than or equal to 8.5 and less than 11 , more preferentially greater than or equal to 9 and less than 11 , in which the pH of the mixture of (Bl) and (B2) has a value of greater than or equal to 6.5 and less than 8, and

the time separating the application of composition (B2) from the application of composition (Bl) is set at a duration of between 0.1 second and 1 hour, preferentially between 0.1 second and 30 minutes and more particularly between 0.1 second and 10 minutes.

- with a composition (Bl) comprising an anionic silica particle sol at a pH of greater than or equal to 8 and less than 11, preferably greater than or equal to 8.5 and less than 11 , more preferentially greater than or equal to 9 and less than 11 , and simultaneously - with a composition (B2), which is different from composition (Bl), and which contains an effective amount of at least one acid,

in which the pH of the resulting composition (Bl) + (B2) is greater than or equal to 6.5 and less than 8.

According to another particular embodiment of the invention, the process is a cosmetic process for preventing and/or treating perspiration and optionally the body odor associated with human perspiration, in which keratin materials, more particularly the skin and even more particularly one or more target areas of the skin are treated with a composition derived from the mixing of two compositions (Bl) and (B2) in which:

- composition (Bl) comprises an anionic silica particle sol at a pH of greater than or equal to 8 and less than 11, preferably greater than or equal to 8.5 and less than 11, more preferentially greater than or equal to 9 and less than 11 , and

- composition (B2) comprises an effective amount of at least one acid in solid form, in which at least one of the compositions (Bl) and/or (B2) is an aqueous solution and the pH of the mixture (B1)+(B2) is greater than or equal to 6.5 and less than 8.

According to another preferred embodiment of the invention, the process is a cosmetic process for preventing and/or treating perspiration and optionally the body odor associated with human perspiration, in which keratin materials, more particularly the skin and even more particularly one or more target areas of the skin are treated:

- with a composition (Bl) comprising an anionic silica particle sol at a pH of greater than or equal to 8 and less than 11, preferably greater than or equal to 8.5 and less than 11 , more preferentially greater than or equal to 9 and less than 11 , and

- with a composition (B2) comprising an effective amount of at least one acid in supported form,

- in which at least one of the compositions (Bl) and/or (B2) is an aqueous solution and the pH of the mixture (B1)+(B2) is greater than or equal to 6.5 and less than 8.

The term "acid in supported form" means, for example, an ion-exchange resin especially such as the resins Amberlyst-15 or Amberlite IR-120 or Dowex 50WX8.

According to this particularly appreciated embodiment of the invention, said process also comprises a step of separating out the acid in supported form, especially as defined previously, before application to the keratin materials, more particularly to the skin and even more particularly to the target area(s) of the skin.

According to an advantageous variant, composition (CI) derived from the mixture (B1)+(B2) after the time (D) is separated from the acid in supported form of composition (B2), for example by filtration, and then applied to the keratin materials, more particularly the skin and even more particularly the target areas of the skin.

According to particular embodiments of the above process, composition (CI) may be obtained on conclusion of mixing of (Bl) and (B2) for a time (D) of between 0.1 second and 1 hour, more particularly between 0.1 second and 45 minutes and preferentially between 1 second and 10 minutes, and then applied to keratin materials, more particularly the skin and even more particularly the target areas of the skin.

Irrespective of the application method, the application temperature is generally room temperature, generally from 15 to 30°C, depending on the climatic conditions.

In all the particular embodiments and variants of the processes described previously, the compositions mentioned (Bl) and (B2) are ready-to-use compositions.

The target areas of the skin are especially those of the armpits, the feet, the hands, the back, the face and the scalp, and more preferentially the armpits. According to another of its aspects, the present invention relates to a multicompartment device or kit comprising a first compartment containing a first composition (Bl) and a second compartment containing a second composition (B2), which are intended to be mixed before application to a keratin material, preferably to the skin, and in particular to one or more target areas or to be applied to a keratin material, preferably to the skin, and in particular to one or more target areas simultaneously, separately or consecutively over time, to form a composition (CI), said first composition (Bl) containing at least one anionic silica particle sol in a stabilized form at a pH of greater than or equal to 8 and less than 11, preferably greater than or equal to 8.5 and less than 11, more preferentially greater than or equal to 9 and less than 11, and said second composition (B2) containing at least one acid in an amount that is effective to adjust the pH of a mixture of the two compositions (B1)+(B2) to a value of greater than or equal to 6.5 and less than 8.

ANIONIC COLLOIDAL SILICA

The colloidal silica particles according to the invention are anionic silica particles.

The term "anionic silica" refers to silica particles bearing at the surface anionic charges neutralized with one or more cations. Such particles are obtained, for example, by reacting silanol groups at the surface of silica particles with alkaline agents such as sodium hydroxide (NaOH) or ammonium hydroxide (NH₄OH).

In composition (Bl), these particles are present in sol form. Preferably, the sol is an aqueous dispersion.

These particles are preferably spherical or approximately spherical. According to a particular form of the invention, these particles are non-porous. The anionic colloidal silica particles according to the invention may be monodisperse or polydisperse. The term "monodisperse" means that the sizes of said particles have a narrow distribution. Conversely, the term "polydisperse" means that the sizes of the particles have a wider distribution.

The mean diameter of the particles is generally between 3 and 100 nm, preferably between 3 and 50 nm and more preferentially between 5 and 10 nm. When the particles are monodisperse, their mean diameter is preferably between 3 and 50 nm, in particular between 5 and 25 nm and more preferentially between 5 and 10 nm.

When the particles are polydisperse, their mean diameter is preferably between 5 and 70 nm, in particular between 10 and 50 nm.

The specific surface area of the silica particles generally ranges from 50 to 500 m²/g Si0₂.

When the particles are monodisperse, their specific surface area generally ranges from 100 to 500 m²/g Si0₂, in particular from 130 to 450 m²/g Si0₂, more preferentially from 320 to 370 m²/g Si0₂.

When the particles are polydisperse, their specific surface area generally ranges from 50 to 300 m²/g Si0₂, in particular from 70 to 280 m²/g Si0₂. As stated above, the anionic silica particles are in the form of an anionic colloidal dispersion, also known as a "sol".

Advantageously, the anionic silica colloidal particles forming the sol of composition (Bl) are silica particles containing stabilizing counterions of cationic nature so as to ensure the electrical neutrality of the particles.

These counterions may be chosen especially from sodium (Na⁺) and ammonium NH₄ ⁺.

According to a particular form of the invention, the cationic counterions are sodium ions (Na+).

Among the anionic silica colloidal dispersions, mention may be made especially of those sold under the name Ludox by the company Grace. In particular, the anionic silica particle dispersions denote the particles sold by the company Grace under the names Ludox FM, Ludox SM, Ludox HS-30, Ludox HS-40, Ludox LS, Ludox TM-40, Ludox TM-50, Ludox PX-30, Ludox PT-40, Ludox PW-50, Ludox SM-AS, Ludox AS-30 and Ludox AS-40.

When the particles are monodisperse, they are preferably chosen from Ludox

FM, Ludox SM, Ludox HS-30, Ludox HS-40, Ludox LS, Ludox TM-40, Ludox TM-50, Ludox SM-AS, Ludox AS-30 and Ludox AS-40. In particular, the anionic colloidal silica particles denote the Ludox SM particles sold by the company Grace.

When the particles are polydisperse, they are preferably chosen from Ludox PX-30, Ludox PT-40 and Ludox PW-50 sold by the company Grace.

The amount of anionic silica colloidal particles (as weight of active material) used in composition (Bl) is generally between 1% and 30% by weight, preferentially 5% to 25%, more preferentially 10% to 20%, more preferentially 12.5% to 18%, even more preferentially about 15% by weight relative to the total weight of composition (Bl) according to the invention.

As stated previously, the colloidal dispersion of anionic silica particles is formulated in a first composition (Bl) intended to be totally or partly mixed with all or part of a second composition (B2) containing an effective amount of at least one acid.

According to a particular form of the invention, compositions (Bl) and (B2) are intended to be mixed in their entirety before use.

According to another form of the invention, compositions (Bl) and (B2) are each intended to be partly mixed before application to the target areas.

ACIDIC COMPONENT

Composition (B2) contains at least one acid intended to adjust the pH of composition (CI) resulting from the mixing of composition (B2) with composition (Bl) which contains the colloidal dispersion of anionic silica particles, to a value of greater than 6.5 and less than 8.

Composition (B2) may contain a single acid or a mixture of acids. Preferably, composition (B2) contains a single acid.

For obvious reasons, the amount of acid required for this adjustment is liable to vary depending on the nature of the acid. This amount is also adjusted to ensure total harmlessness for the target area of the skin intended to be in contact with this acid, preferably such that the final pH is greater than or equal to 6.5. The adjustment of this amount clearly falls within the competence of a person skilled in the art.

This acid may be used in a solid form, and/or in a supported form, and/or in a dissolved form, in particular dissolved in aqueous medium. As a nonlimiting illustration of the field of the invention, this acid may be chosen from:

i) mineral acids and halogenated acids, for instance hydrochloric acid HC1, hydrobromic acid HBr, sulfuric acid H2SO4,

ii) (Ci-C6)alkylsulfonic acids, Alk-S(0)20H, for instance methylsulfonic acid and ethylsulfonic acid;

iii) arylsulfonic acids, Ar-S(0)₂0H, with Ar representing an aryl group, in particular phenyl, for instance benzenesulfonic acid and toluenesulfonic acid;

iv) (poly)(hydroxy)(Ci-C6)alkylcarboxylic acids, for instance citric acid; succinic acid; tartaric acid and lactic acid,

v) (Ci-C6)alkoxysulfinic acids: Alk-0-S(0)OH, for instance methoxysulfinic acid and ethoxysulfmic acid;

vi) aryloxysulfinic acids, for instance tolueneoxysulfinic acid and phenoxysulfinic acid;

vii) phosphorus acids, in particular phosphoric acid H3PO4;

viii) (Ci-C6)alkylcarboxylic acids, for instance acetic acid CHBC(0)OH;

ix) triflic acid CF3SO3H;

x) tetrafluoroboric acid HBF₄;

xi) "acidic" amino acids, for instance aspartic acid or glutamic acid and also homopolymers or copolymers thereof with a mass generally between 1000 and 100 000 g/mol;

xii) acidic resins, and

xiii) "acidic" copolymers containing carboxylic and/or sulfonic and/or phosphoric acid functions, for instance poly(acrylic acid), poly(vinylsulfonic acid) or poly(APSA).

The amino acid homopolymers and copolymers may especially be the products Baypure DS-100 sold by Bayer, Donlar® C-10D, Donlar® C-20C, Donlar® C-30D, Donlar® C-50D, Donlar® A-2C, Donlar® A-3C, Donlar® B-3D and Donlar® A-5D, sold by Nanotech; and γ-PGA form H, or PEO-PGA, or PGLA sold by Bayer, and gamma- polyglutamic acid sold by Ichimaru Pharcos and Natto Bio Sciences. The acidic compound may also denote polyaspartic derivatives such as the acid Aquadew SPA-30 sold by Ajinomoto, DS-910 from Desai Chem and Baypure Ds 100 from Lanxessou and sodium polyaspartate C-30D or C-50D from Akzo Nobel.

The acidic copolymers may especially be the carbomer products Carbopol 980 and 981 from Lubrizol and Merquat from Lubrizol and Revcare Natural Effects (sodium polyitaconate) sold by the company Revolymer.

The acidic resins may especially be the products Amberlyst-15, Amberjet- 1200, Amberlite IR-120, Amberlite IRC-86, Amberlite IRC-50 and Dowex 50WX8.

As indicated previously, composition (B2) may contain a mixture of acids.

According to a first embodiment, composition (B2) comprises an acid or a mixture of acids in a concentration ranging from 0.05% to 15% by weight, preferentially from 0.25% to 10% and more preferentially from 0.3% to 5% by weight relative to the total weight of composition (B2).

Preferably, composition (B2) is in optionally thickened aqueous form.

According to this embodiment variant, the acid under consideration is thus preferably chosen from hydrochloric acid, lactic acid, gly colic acid and citric acid.

Preferably, the acid is hydrochloric acid and/or lactic acid.

In a particular embodiment of this variant, the aqueous acidic solution is not at all thickened. In other words, it is free of gelling agent and/or thickener.

In another embodiment, composition (B2) is an acidic solid such as an acidic resin.

Thus, according to this embodiment variant, the acid under consideration is preferably chosen from the resins Amberlyst-15, Amberlite IR-120 and Dowex 50WX8.

Irrespective of the embodiment considered, the concentration of acid included in composition (B2) is such that, during the mixing of composition (B2) with composition (Bl) containing the colloidal dispersion of anionic silica particles, extemporaneously or directly on the target area of skin, the amount of acid is sufficient to adjust the pH of the mixture to a value of greater than or equal to 6.5 and less than 8, in particular ranging from 6.6 to 7.8, more preferentially from 6.8 to 7.5, even more preferentially to a pH of about 7, such as 7 ± 0.1, in particular 7. According to another particular embodiment variant, Composition (B2) according to the invention is advantageously free of cationic surfactant and of cationic polymer, in particular free of polyalkyleneimine, for instance polyethyleneimines and homopolymers of a diallyldimethylammonium salt, such as dimethyldiallylammonium chloride, for instance the product referenced under the INCI name Polyquaternium-6.

According to another particular embodiment variant, composition (CI) resulting from the mixing of compositions (Bl) and (B2) defined previously is free of cationic surfactant and of cationic polymer, in particular free of polyalkyleneimine, for instance polyethyleneimines and of diallyldimethylammonium salt, such as dimethyldiallylammonium chloride, for instance the product referenced under the INCI name Polyquaternium-6.

COMPOSITIONS (Bl) and (B2) ACCORDING TO THE INVENTION

Composition (CI) according to the invention formed from the mixing of compositions (Bl) and (B2) as defined previously also comprises a physiologically acceptable medium.

A physiologically acceptable medium is preferentially a cosmetically or dermato logically acceptable medium, i.e. a medium that has no unpleasant odor or appearance, and that is entirely compatible with the topical administration route.

In the present case in which the composition is intended for topical administration to a keratin material, i.e. by application to the surface of a target area of skin, such a medium is considered in particular to be physiologically acceptable when it does not cause discomfort, such as tautness that is unacceptable to the user.

In a preferred embodiment, the physiologically acceptable medium comprises water and optionally at least one organic solvent.

According to a particular embodiment, composition (CI) under consideration according to the invention, in contact with the keratin material, may also comprise at least one deodorant active agent and/or one antiperspirant active agent other than the anionic silica colloidal particles contained in composition (CI) according to the invention. In the context of the present invention, the term "deodorant active agent" means any active agent which, by itself, has the effect of masking, absorbing, improving and/or reducing the unpleasant odor resulting from the decomposition of human sweat.

As illustrations of these additional deodorant active agents, mention may be made especially of bacteriostatic agents or bactericides that act on underarm odor microorganisms, such as 2,4,4'-trichloro-2'-hydroxydiphenyl ether (©Triclosan), 2,4- dichloro-2'-hydroxydiphenyl ether, 3',4',5'-trichlorosalicylanilide, l-(3',4'- dichlorophenyl)-3-(4'-chlorophenyl)urea (©Triclocarban) or 3,7,11 -trimethyldodeca- 2,5,10-trienol (©Farnesol); quaternary ammonium salts such as cetyltrimethylammonium salts, cetylpyridinium salts, polyols such as those of glycerol type, 1,3-propanediol (Zemea Propanediol® sold by DuPont Tate & Lyle Bio Products), 1,2-decanediol (Symclariol® from the company Symrise), glycerol derivatives, for instance caprylic/capric glycerides (Capmul MCM® from Abitec), glyceryl caprylate or caprate (Dermosoft GMCY® and Dermosoft GMC®, respectively from Straetmans), Polyglyceryl-2 caprate (Dermosoft DGMC® from Straetmans), biguanide derivatives, for instance polyhexamethylene biguanide salts; chlorhexidine and salts thereof; 4-phenyl-4,4-dimethyl-2-butanol (Symdeo MPP® from Symrise); cyclodextrins; chelating agents such as Tetrasodium Glutamate Diacetate (CAS #51981-21-6) sold under the trade name Dissolvine GL-47-S® from AkzoNobel, EDTA and DPTA (1,3-diaminopropanetetraacetic acid).

Among the additional deodorant active agents in accordance with the invention, mention may also be made of:

- zinc salts, such as zinc salicylate, zinc phenolsulfonate, zinc pyrrolidonecarboxylate (more commonly known as zinc pidolate), zinc sulfate, zinc chloride, zinc lactate, zinc gluconate, zinc ricinoleate, zinc glycinate, zinc carbonate, zinc citrate, zinc chloride, zinc laurate, zinc oleate, zinc orthophosphate, zinc stearate, zinc tartrate, zinc acetate or mixtures thereof;

- odor absorbers such as zeolites, especially silver-free metal zeolites, cyclodextrins, metal oxide silicates such as those described in patent application US 2005/063 928; metal oxide particles modified with a transition metal, as described in patent applications US 2005/084 464 and US 2005/084 474, aluminosilicates such as those described in patent application EP 1 658 863, chitosan-based particles such as those described in patent US 6 916 465;

- sodium bicarbonate; - alum.

The additional deodorant active agents may preferably be present in the compositions according to the invention in weight concentrations ranging from 0.01% to 10% by weight relative to the total weight of the composition.

The term "antiperspirant active agent" means any substance which, by itself, has the effect of reducing the flow of sweat, of reducing the sensation on the skin of moisture associated with human sweat or of masking human sweat.

As illustrations of these antiperspirant active agents, mention may be made especially of the antiperspirant salts or complexes of aluminum and/or of zirconium, preferably chosen from aluminum halohydrates; aluminum zirconium halohydrates, complexes of zirconium hydroxychloride and of aluminum hydroxychloride with or without an amino acid, such as those described in patent US-3 792 068. Among the aluminum salts, mention may in particular be made of aluminum chlorohydrate in activated or unactivated form, aluminum chlorohydrex, the aluminum chlorohydrex- polyethylene glycol complex, the aluminum chlorohydrex-propylene glycol complex, aluminum dichlorohydrate, the aluminum dichlorohydrex-polyethylene glycol complex, the aluminum dichlorohydrex-propylene glycol complex, aluminum sesquichlorohydrate, the aluminum sesquichlorohydrex-poly ethylene glycol complex, the aluminum sesquichlorohydrex-propylene glycol complex, aluminum sulfate buffered with sodium aluminum lactate.

Among the aluminum zirconium salts, mention may be made in particular of aluminum zirconium octachlorohydrate, aluminum zirconium pentachlorohydrate, aluminum zirconium tetrachlorohydrate and aluminum zirconium trichlorohydrate.

The complexes of zirconium hydroxychloride and of aluminum hydroxychloride with an amino acid are generally known under the name ZAG (when the amino acid is glycine). Among these products, mention may be made of the aluminum zirconium octachlorohydrex-glycine complexes, the aluminum zirconium pentachlorohydrex-glycine complexes, the aluminum zirconium tetrachlorohydrex-glycine complexes and the aluminum zirconium trichlorohydrex-glycine complexes.

Aluminum sesquichlorohydrate is in particular sold under the trade name Reach 301® by the company Summitreheis. Among the aluminum and zirconium salts, mention may be made of the complexes of zirconium hydroxychloride and of aluminum hydroxychloride with an amino acid such as glycine, having the INCI name: Aluminum Zirconium Tetrachlorohydrex Gly, for example the product sold under the name Reach AZP-908-SUF® by the company Summitreheis.

Use will be made more particularly of aluminum chlorohydrate in activated or unactivated form sold under the trade names Locron S FLA®, Locron P and Locron L.ZA by the company Clariant; under the trade names Microdry Aluminum Chlorohydrate®, Micro-Dry 323®, Chlorhydrol 50, Reach 103 and Reach 501 by the company Summitreheis; under the trade name Westchlor 200® by the company Westwood; under the trade name Aloxicoll PF 40® by the company Guilini Chemie; Cluron 50%® by the company Industria Quimica Del Centra; or Clorohidroxido Aluminio SO A 50%® by the company Finquimica.

As other antiperspirant active agents, mention may be made of expanded perlite particles such as those obtained by the expansion process described in patent US 5 002 698.

Composition (CI) formed by mixing compositions (Bl) and (B2) may also contain one or more cosmetic adjuvants intended, for example, for fragrancing, coloring or thickening composition (CI), for protecting the target areas of application of said composition against solar radiation, such as UV-screening agents, or for moisturizing the target areas of application of said composition (CI).

Needless to say, a person skilled in the art will take care to select these optional adjuvants so that they do not interfere with the implementation processes detailed previously.

The above additives are generally present in an amount, for each of them, of between 0.01% and 20% by weight relative to the total weight of the composition.

In particular, a person skilled in the art will take care to select this or these optional additives such that the formation of plugs in the sweat ducts is not, or is not substantially, impaired by their presence.

Similarly, it is within the capacity of a person skilled in the art to favor the packaging of these additives in compositions (Bl) and/or (B2) taking into account the compatibility and chemical inertness of this additive with regard to the colloidal dispersion of anionic silica particles contained in (Bl) and of the acid(s) contained in (B2).

Composition (CI), and similarly compositions (Bl) and (B2) from which it is derived, may especially be in the form of a suspension, a dispersion, a solution, in particular an aqueous solution, an emulsion, especially an oil-in-water (O/W) or water-in- oil (W/O) emulsion, or a multiple emulsion (W/O/W or polyol/O/W or 0/W/O), in the form of a cream, a mousse, a stick, a dispersion of vesicles, especially of ionic or nonionic lipids, a two-phase or multiphase lotion, or a spray. A person skilled in the art can choose the appropriate presentation form, and also its method of preparation, on the basis of his general knowledge, taking into account first the nature of the constituents used, especially their solubility in the support, and secondly the application envisaged for the composition.

DEVICE OR KIT ACCORDING TO THE INVENTION

Another subject of the present invention relates to a multi- compartment device or kit comprising a first compartment containing composition (Bl) and a second compartment containing composition (B2), (Bl) and (B2) being intended to be mixed before application to a keratin material, preferably to the skin, and in particular to one or more target areas or to be applied to a keratin material, preferably to the skin, and in particular to one or more target areas simultaneously, separately or consecutively over time, to form a composition (CI), said first composition (Bl) containing at least one anionic silica particle sol in a stabilized form at a pH of greater than or equal to 8 and less than 11, preferably greater than or equal to 8.5 and less than 11, more preferentially greater than or equal to 9 and less than 11 , and said second composition (B2) containing at least one acid in an amount that is effective to adjust the pH of a mixture of the two compositions (B1)+(B2) to a value of greater than or equal to 6.5 and less than 8.

According to a particular form, the second compartment contains composition (B2) which is in the form of an optionally thickened aqueous solution.

According to another form of the invention, the two compartments are separated by a wall that can be broken. This wall can be broken definitively or temporarily.

The multi-compartment device or kit may be a pump bottle, a tube or a stick comprising two applicators. It should be noted that when compositions (Bl) and (B2) as defined previously are packaged in an aerosol device, this device comprises one or more identical or different propellants, which may be chosen from volatile hydrocarbons such as n-butane, propane, isobutane, pentane and halogenated hydrocarbons, and mixtures thereof.

Carbon dioxide, nitrous oxide, dimethyl ether (DME), nitrogen or compressed air may also be used as propellant. Mixtures of propellants may also be used. Dimethyl ether is preferably used.

Advantageously, the propellant may be present in a concentration of between 5% and 90% by weight and more particularly in a concentration of between 10% and 60% by weight relative to the total weight of the composition under consideration in the aerosol device.

When the compositions (Bl) and (B2) are applied separately, they may be in identical presentation forms or different presentation forms.

When composition (B2) is in liquid form, the two compositions (Bl) and (B2) are conditioned in separate compartments and placed in contact at the time of use. If the kit is a multiple-use kit, the base of the kit which contained a mixture of the two compositions (Bl) and (B2) will be rinsed with water, preferably with hot water, after each use.

When the second composition is a solid, the kit may contain a membrane separating the two compositions (Bl) and (B2), this membrane being broken at the time of use to allow mixing of the first and second components. This kit will preferentially be a single-use kit.

The examples that follow are presented as nonlimiting illustrations of the field of the invention.

MATERIALS AND METHOD

A) Protocol for the in vitro qualitative evaluation of antiperspirant activity in a

microfluidic tool

The microfluidic method used is detailed in WO 2014/170174. This tool makes it possible via a physicochemical route to evaluate qualitatively potential antiperspirant activity of a mimetic active agent of aluminum salts (ACH). It allows the preparation of an in vitro system modeling the physics and consequently the specificity of sweat flows such as take place in vivo. Consequently, it allows quantitative observation (formation of floes, aggregates and plugs, etc.) between the active agents in solution and the constituents of sweat under mimetic sweating conditions. Thus, the formation of a plug on contact with the ducts containing, on the one hand, sweat, and, on the other hand, the compound to be evaluated, indicates that the compound to be evaluated effectively blocks the passage of sweat and consequently has antiperspirant activity.

In the test adopted, the microsystem made of PDMS (polydimethylsiloxane) comprises a main duct intended to receive the antiperspirant (55 μιη long and 400 μιη wide) and a straight duct (55 μιη long and 300 μιη wide) into which is injected a model of artificial sweat containing various concentrations of CaC12 at various pH values, mimicking the sweat duct. Once the microsystem has been closed in a leaktight manner, the flows are controlled by means of a syringe plunger. The nominal flow rate of sweat is 0.1 nL/s and that of the antiperspirant duct is 1 nL/s. Once the stationary regime has been established, the fluids flow at a controlled rate in a laminar regime and their interactions are observed by light microscopy. An image is recorded every 15 seconds for 30 minutes.

Synthetic sweat was prepared as follows:

In the test, this sweat was reproduced by adding variable concentrations of sodium hydroxide, to illustrate various pH values representative of the diversity naturally encountered in sweat. B) Qualitative in- vitro measurement of a transfer of formula onto clothing

This measurement makes it possible to demonstrate the transfer onto clothing and the appearance of white marks. It is performed using a black 100% cotton fabric. The formula of the composition tested is applied onto a model of Bioskin® Plate 20 artificial skin (reference K278, supplied by Maprecos, France) and the fabric is then deposited using a slight pressure (tapping) to imitate the transfer onto clothing. The observations on the fabric are made at different drying times (tO, 1 minute, 5 minutes, 30 minutes, 2 hours and 12 hours). EXAMPLE 1

Composition (CI) in accordance with the invention

The anionic colloidal silica sold under the name Ludox SM by the company Grace (compound A) is diluted in distilled water adjusted to a pH of 7 by addition of lactic acid.

The composition of this formulation is detailed below.

This composition was evaluated in the microfluidic system with the sweat detailed above in the section entitled Materials and Methods.

The results for composition CI of the invention at pH 7 are presented in table 1 below.

Table 1

Tests Sweat - pH Observations

Cl .a Sweat - pH 5 Sparingly dense gelled membrane plug, not very deep in the sweat duct

Cl .b Sweat - pH 6.5 Very dense gelled membrane plug, deep in the sweat duct

Cl .c Sweat - pH 7 Dense gelled membrane plug, not very deep in the sweat duct

Cl .d Sweat - pH 8 Sparingly dense gelled membrane plug, not very deep in the sweat duct

It is seen that, in this model test of the sweat duct, the application of composition (CI) under the conditions tested leads to the formation of a plug, as observed for the aluminum salts. However, the density of the plug formed with the compositions at pH 5 and 8 is insufficient and does not make it possible to obtain satisfactory antiperspirant properties. In contrast, the compositions (CI) with a pH of 6.5 and a pH of 7 generate a dense plug and show good antiperspirant properties.

EXAMPLE 2

Qualitative in-vitro measurement of a transfer of formula onto clothing for a composition of the invention

Composition CI (pH = 7) prepared in example 1 is tested, less than 10 minutes after its preparation and at room temperature, according to the methodology "Qualitative in vitro measurement of a transfer of formula onto clothing" detailed in the Materials and Methods section.

200 μΙ_, of solution (CI) described above are applied to the model of artificial skin detailed above. The results are presented in table 2 below.

Table 2

Time Observations

1 min No staining

5 min No staining

30 min No staining 2 hours No staining

12 hours No staining

It is thus seen that composition CI according to the invention does not create any white deposit on the black fabric and thus makes it possible to efficiently limit the transfer onto clothing.

EXAMPLE 3

Qualitative in-vitro measurement of a transfer of formula onto clothing for two compositions outside of the invention

Compositions outside of the invention are prepared as detailed below:

NAME COMPOSITION Dla

Anionic silica sold under the name Ludox 7 g AM

AM by the company Grace

Water Qs 100 g

NAME COMPOSITION Dlb

Polyethyleneimine-35 5 g AM

Hydrochloric acid Qs pH 6.7

Water 14 g

NAME COMPOSITION D2a

Anionic silica sold under the name Ludox 7 g AM

AM by the company Grace

Water Qs 100 g NAME COMPOSITION D2b

Polyquaternium-6 sold under the name 5 g AM

Merquat 106 by the company Grace

Hydrochloric acid Qs pH 6.7

Water 14 g

The amount of water in the first composition Dla is adjusted so as to obtain a total amount of 100 g after mixing said first composition with the second composition Dlb. The same approach was considered regarding the first and second compositions D2a and D2b.

On an artificial skin model, 100 of the first composition Dla are applied. Two minutes after application, 100 of the second composition Dlb are applied.

On an artificial skin model, 100 of the first composition D2a are applied. Two minutes after application, 100 μΐ_^ of composition D2b are applied.

The staining is then measured according to the "Qualitative in- vitro measurement of a transfer of formula onto clothing" protocol which is described in the "Materials and method" section above.

The results are presented in table 3 below.

Table 3

Composition Time Observations

Dl 1 min Slight staining

D2 1 min Very slight staining

Dl 5 min Staining

D2 5 min Slight staining

Dl 30 min Staining

D2 30 min Slight staining

Dl 2 h Strong staining D2 2 h Staining

Dl 12 h Very strong staining

D2 12 h Strong staining

Thus, it has been observed that the white stains increase over time and therefore transfer more onto the clothing with compositions Dl and D2.

Claims

1. A cosmetic process for preventing and/or treating perspiration and optionally the body odor associated with human perspiration, characterized in that it comprises at least the placing in contact of a keratin material, more particularly of the skin and more particularly of one or more target areas of the skin, with a composition (CI) whose pH is greater than or equal to 6.5 and less than 8 and comprising an effective amount of at least one colloidal dispersion of anionic silica particles, said composition (CI) being constituted extemporaneously by mixing:

- a first composition (Bl) containing a sol of said anionic silica particles at a pH of greater than or equal to 8 and less than 11 , preferably greater than or equal to 8.5 and less than 11, more preferentially greater than or equal to 9 and less than 11 , and

2. The process as claimed in the preceding claim, in which the pH of composition (CI) ranges from 6.6 to 7.8, in particular from 6.8 to 7.5, preferably is about 7, such as 7 ± 0.1 , and in particular is 7.

3. The process as claimed in either of the preceding claims, in which said composition (CI) is formed on contact with the keratin material by sequential application of said compositions (Bl) and (B2).

4. The process as claimed in claim 1 or 2, in which said composition (CI) is formed on contact with the keratin material by simultaneous application of said compositions (Bl) and (B2).

5. The process as claimed in claim 1 or 2, in which said composition (CI) is formed prior to its application to said keratin material, by extemporaneous mixing of all or part of the first composition (Bl) with all or part of the second composition (B2).

6. The process as claimed in the preceding claim, in which composition (CI) is obtained on conclusion of mixing of (B1)+(B2) for a time of between 0.1 second and 1 hour, more particularly between 0.1 second and 45 minutes and preferentially between 1 second and 10 minutes, and then applied to said keratin material.

7. A cosmetic process for preventing and/or treating perspiration and optionally the body odor associated with human perspiration, in which keratin materials, more particularly the skin and even more particularly one or more target areas of the skin are treated:

with a composition (Bl) comprising an anionic silica particle sol at a pH of greater than or equal to 8 and less than 11 , preferably greater than or equal to 8.5 and less than 11, more preferentially greater than or equal to 9 and less than 11 , and then

with a composition (B2), which is different from composition (Bl), and which contains an effective amount of at least one acid to adjust the pH of the mixture of (Bl) and (B2) to a value of greater than or equal to 6.5 and less than 8, in which the pH of the mixture of (Bl) and (B2) has a value of greater than or equal to 6.5 and less than 8, and

8. A cosmetic process for preventing and/or treating perspiration and optionally the body odor associated with human perspiration, in which keratin materials, more particularly the skin and even more particularly one or more target areas of the skin are treated:

with a composition (B2), containing an effective amount of at least one acid to adjust the pH of the mixture of (Bl + B2) to a value of greater than 6.5 and less than 8, and then

with a composition (Bl), which is different from composition (B2) and which comprises an anionic silica particle sol at a pH of greater than or equal to 8 and less than 11, preferably greater than or equal to 8.5 and less than 11, more preferentially greater than or equal to 9 and less than 11 ,

9. A cosmetic process for preventing and/or treating perspiration and optionally the body odor associated with human perspiration, in which keratin materials, more particularly the skin and even more particularly one or more target areas of the skin are treated:

with a composition (Bl) comprising an anionic silica particle sol at a pH of greater than or equal to 8 and less than 11 , preferably greater than or equal to 8.5 and less than 11, more preferentially greater than or equal to 9 and less than 11 , and simultaneously

with a composition (B2), which is different from composition (Bl), and which contains an effective amount of at least one acid,

10. A cosmetic process for preventing and/or treating perspiration and optionally the body odor associated with human perspiration, in which keratin materials, more particularly the skin and even more particularly one or more target areas of the skin are treated with a composition derived from the mixing of two compositions (Bl) and (B2) in which:

composition (Bl) comprises an anionic silica particle sol at a pH of greater than or equal to 8 and less than 11, preferably greater than or equal to 8.5 and less than 11 , more preferentially greater than or equal to 9 and less than 11 , and composition (B2) comprises an effective amount of at least one acid in solid form,

in which at least one of the compositions (Bl) and/or (B2) is an aqueous solution and the pH of the mixture (B1)+(B2) is greater than or equal to 6.5 and less than 8.

11. A cosmetic process for preventing and/or treating perspiration and optionally the body odor associated with human perspiration, in which keratin materials, more particularly the skin and even more particularly one or more target areas of the skin are treated:

with a composition (Bl) comprising an anionic silica particle sol at a pH of greater than or equal to 8 and less than 11 , preferably greater than or equal to

8.5 and less than 11, more preferentially greater than or equal to 9 and less than

11. and

with a composition (B2) comprising an effective amount of at least one acid in supported form,

12. The process as claimed in the preceding claim, in which said supported acid is an ion-exchange resin.

13. The process as claimed in claim 10, 11 or 12, in which composition (CI) is obtained on conclusion of mixing of (Bl) and (B2) for a time of between 0.1 second and 1 hour, more particularly between 0.1 second and 45 minutes and preferentially between 1 second and 10 minutes, and then applied to said keratin materials.

14. The process as claimed in claim 11, 12 or 13, also comprising a step of separating out the acid in supported form, especially by filtration, before application to the keratin materials.

15. The process as claimed in any one of the preceding claims, in which the anionic silica colloidal particles forming the sol of composition (Bl) are silica particles containing stabilizing counterions of cationic nature chosen in particular from sodium (Na⁺) and ammonium NH⁴+.

16. The process as claimed in any one of the preceding claims, in which the anionic silica colloidal particles forming the sol of composition (Bl) are monodisperse or polydisperse.

17. The process as claimed in any one of the preceding claims, in which composition (Bl) comprises from 1% to 30% by weight, preferentially from 5% to 25%, more preferentially 10% to 20%, more preferentially 12.5% to 18%, even more preferentially about 15% by weight of anionic silica colloidal particles (expressed as weight of active material) relative to the total weight thereof.

18. The process as claimed in any one of the preceding claims, in which composition (B2) comprises an acid or a mixture of acids in a concentration ranging from 0.05% to 15% by weight, preferentially from 0.25% to 10% and more preferentially from 0.3% to 5% by weight relative to the total weight of composition (B2).

19. The process as claimed in any one of the preceding claims, in which the acid is chosen from mineral acids and halogenated acids, (Ci-C6)alkylsulfonic acids, arylsulfonic acids, with Ar representing an aryl group, (poly)(hydroxy)(Ci- C₆)alkylcarboxylic acids, (Ci-C6)alkoxysulfmic acids, aryloxysulfinic acids, phosphorus acids, (Ci-C6)alkylcarboxylic acids, triflic acid, tetrafluoroboric acid, "acidic" amino acids, acidic resins and "acidic" copolymers containing carboxylic and/or sulfonic and/or phosphoric acid functions.

20. The process as claimed in any one of claims 1 to 10 and 15 to 19, in which composition (B2) is in an optionally thickened aqueous form and preferably contains at least one acid chosen from hydrochloric acid, lactic acid, glycolic acid and citric acid.

21. The process as claimed in any one of the preceding claims, characterized in that composition (CI), in contact with the keratin material, also comprises at least one deodorant active agent and/or one antiperspirant active agent other than said anionic silica colloidal particles.

22. A multi-compartment device or kit comprising a first compartment containing a first composition (Bl) and a second compartment containing a second composition (B2), which are intended to be mixed before application to a keratin material, preferably to the skin, and in particular to one or more target areas or to be applied to a keratin material, preferably to the skin, and in particular to one or more target areas simultaneously, separately or consecutively over time, to form a composition (CI), said first composition (Bl) containing at least one anionic silica particle sol in a stabilized form at a pH of greater than or equal to 8 and less than 11, preferably greater than or equal to 8.5 and less than 11 , more preferentially greater than or equal to 9 and less than 11 , and said second composition (B2) containing at least one acid in an amount that is effective to adjust the pH of a mixture of the two compositions (B1)+(B2) to a value of greater than or equal to 6.5 and less than 8.

23. The device as claimed in the preceding claim, in which composition (Bl) is as defined in claims 15 to 17.

24. The device as claimed in claim 22 or 23, in which composition (B2) is as defined in claims 18 to 19.

25. The device as claimed in any one of claims 22 to 24, of a type such as a pump bottle, a tube or a stick comprising two applicators.