Patent Description:
Hyaluronic acid is known for its film-forming and water-retaining power. Hyaluronic acid is a predominant glycosaminoglycan located in the skin. This compound, and the salts thereof, are conventionally used in cosmetics for their hygroscopic, viscoelastic and rheological properties, advantageously making it possible to moisturize and plump up the skin, and to reduce wrinkles and dehydration lines, with anti-aging effects. The hyaluronic acids most commonly used for the abovementioned applications are macromolecules of a molecular weight of between <NUM> kDa and <NUM><NUM> kDa. Indeed, it has been demonstrated that supplying these high-molecular-weight hyaluronic acids provides an effective moisturizing effect to the skin, by virtue of their hygroscopic properties which are characteristic of these molecules.

Spring and/or mineral waters, and in particular spring and/or mineral waters having a mineralization of at least <NUM>/l, are known for their soothing effect on the skin. They are commonly used in dermatological or cosmetic compositions at contents not exceeding <NUM>% by weight relative to the total weight of the composition, due to the potential risk of depolymerization and crystallization of the minerals which they contain.

<CIT> relates to cosmetic preparations comprising at least <NUM>% of thermal mineral waters within the aqueous portion of the formulation. However, none of these cosmetic preparations are in the form of a single-phase composition and even less under the form of a gel. It has thus been observed that, in the presence of a high content of spring and/or mineral water, and due to its high mineralization, hyaluronic acid tends to cause phase separation of the composition containing it, which is of course a phenomenon to be avoided.

There therefore remains a need to provide care compositions, more particularly in the form of aqueous gels, or even of transparent gels, comprising hyaluronic acid and a high content of spring and/or mineral water.

Thus, according to a first of its aspects, the present invention relates to a composition according to claim <NUM>.

Herein is described and not encompassed by the wording of the claims, a composition especially an aqueous composition, comprising hyaluronic acid or a salt thereof, spring and/or mineral water in a content greater than <NUM>% by weight relative to the total weight of the composition, and at least one acrylic acid polymer, a copolymer of acrylic acid and of alkylacrylate, or one of the mixtures thereof.

The composition according to the present invention is in the form of a gel and in particular in the form of a transparent gel. In terms of sensory aspect, said gel may advantageously be qualified as lightweight gel texture, which is very well appreciated by the users. It may also be described as providing skin feeling fresh and not sticky or greasy-looking.

More precisely, the inventors have observed that the specific choice of one of these specific gelling polymers made it possible to mitigate the phase separation caused by the combination, within an aqueous composition, of hyaluronic acid or a salt thereof and of spring and/or mineral water in a content greater than <NUM>% by weight relative to the total weight of the composition.

Moreover, the inventors have observed that the composition according to the present invention has the advantage of providing users with a very advantageous sensory aspect. Thus, it has been observed that on application the skin appeared softer, more moisturized, firmer, more elastic and/or more plumped. It has also been observed that the composition according to the present invention helped to fortify and make the skin more resistant to help protect it against external aggressors like pollution and cold weather or against stress and fatigue. In other words, the composition reinforces the cutaneous barrier.

In addition, against all expectations and as demonstrated in the experimental section below, the inventors actually observed that these specific gelling polymers made it possible to ensure physicochemical stability of the compositions thus obtained.

The present invention also targets a process for the cosmetic treatment of keratin materials and especially the skin, and even more particularly the skin of the face, comprising at least the application, to said keratin materials, of a composition according to the invention.

The present invention further relates to a process for the cosmetic treatment as claimed in claim <NUM>.

The present invention also relates to a process for the cosmetic treatment of an aged, especially wrinkled, skin, comprising the application, to said skin, of at least one composition according to the present invention, in an effective amount for toning down wrinkles.

The present invention also relates to a process for the cosmetic treatment of a dry skin, comprising the application, to said skin, of at least one composition according to the present invention, in an effective amount for improving the moisturization thereof.

The present invention also relates to a process for the cosmetic treatment of a skin affected by external aggressors like pollution and cold weather or by stress and fatigue, comprising the application, to said skin, of at least one composition according to the present invention, in an effective amount for improving the cutaneous barrier thereof.

Herein is described and not encompassed by the wording of the claims, the use of at least one acrylic acid polymer, of at least one copolymer of acrylic acid and of alkylacrylate or of at least one of the mixtures thereof, with a view to stabilizing a composition comprising hyaluronic acid or a salt thereof and spring and/or mineral water in a content greater than <NUM>% by weight, or even than <NUM>% by weight or else than <NUM>% by weight relative to the total weight of said composition.

The composition according to the invention is advantageously cosmetic.

The term "cosmetic composition" is intended to mean a substance or a preparation intended to be brought into contact with the various superficial parts of the human body, especially the epidermis, the lips and the oral mucous membranes, with a view, exclusively or mainly, to cleansing them, making them more attractive, fragrancing them, modifying their appearance, protecting them, keeping them in good condition, or correcting body odors.

The composition according to the invention may comprise a "physiologically acceptable medium".

For the purposes of the present invention, the term "physiologically acceptable medium" is intended to mean a medium that is suitable for the topical administration of a composition, and that is compatible with all human keratin materials, such as the skin, the lips, the nails, the mucous membranes, the eyelashes, the eyebrows, the scalp and/or the hair, or any other area of bodily skin. According to the invention, a physiologically acceptable medium is preferentially a cosmetically acceptable medium, that is to say a medium which is free of any odor or unpleasant appearance, and which is entirely compatible with the topical administration route.

More particularly, the composition according to the invention is suitable for topical administration, that is to say for application to the surface of the keratin material under consideration, such as the skin.

According to the invention, the term "keratin materials" is intended to mean the skin, of the body, face and/or area around the eyes, the lips, the nails, the mucous membranes, the eyelashes, the eyebrows, bodily hair, the scalp and/or the hair, or any other area of bodily skin. More particularly, the keratin materials according to the invention are the scalp, the hair and/or the skin.

Preferably, the keratin material according to the invention is the skin.

The term "skin" is intended to mean all of the skin of the body, and preferably the skin of the face, neckline, neck, arms and forearms, or even more preferably still the skin of the face, especially of the forehead, nose, cheeks, chin and area around the eyes.

A composition according to the invention has an aqueous phase which advantageously constitutes its only fluid phase. As specified above, a composition according to the invention is advantageously a single-phase composition. In other words, it is different from an emulsion and is different from a composition comprising liposomes.

The present invention is directed to a single-phase composition.

The present invention relates to a transparent composition, and more particularly to a transparent gel.

For the purposes of the present invention, the term "mineralization" means the sum of the concentrations of anions and cations present in the spring or mineral water.

The present invention may use, without preference, a spring water or a mineral water or a mixture of the two. In general, a mineral water is fit for consumption, which is not always the case with a spring water. Each of these waters contains, inter alia, dissolved minerals and trace elements. These waters are known to be employed for specific treatment purposes according to the particular trace elements and minerals that they contain, such as the moisturization and desensitization of the skin or the soothing care of the skin.

The spring water or mineral water used according to the invention may in particular be chosen from the waters of the Vichy basin.

Among the waters of the Vichy basin, mention may be made of Lucas water, l'Hôpital water, and Grande Grille water.

According to a particular embodiment of the invention, the spring and/or mineral water may have a mineralization of greater than <NUM>/l, especially greater than <NUM>/l.

According to another particular embodiment of the present invention, the spring and/or mineral water have a mineralization of greater than <NUM>/l, <NUM>/l, <NUM>/l and even <NUM>/l.

The spring and/or mineral water used according to the invention may have a mineralization of at least <NUM>/l, and in particular have a total concentration of carbonates and bicarbonates of at least <NUM>/l and more preferentially of at least <NUM>/l and especially of sodium carbonate and bicarbonate of greater than <NUM>/l.

The concentration of silicon oxide in the water used in the composition according to the invention may preferably be at least <NUM>/l and more preferentially at least <NUM>/l.

According to a particular embodiment, the spring and/or mineral water is present in an amount greater than <NUM>% by weight, preferably greater than <NUM>% and better still ranging from <NUM>% to <NUM>%, or even ranging from <NUM>% to <NUM>%, or else ranging from <NUM>% to <NUM> % by weight relative to the total weight of the composition. The spring or mineral water may be supplemented with distilled or demineralized water in the composition.

For the purposes of the present invention, hyaluronic acid also covers the salts thereof.

Within the context of the present invention, the term "hyaluronic acid or a salt thereof" especially covers the basic unit of hyaluronic acid, of formula:
<CHM>.

This is the smallest fraction of hyaluronic acid, comprising a disaccharide dimer, namely D-glucuronic acid and N-acetylglucosamine.

The term "hyaluronic acid or a salt thereof" also comprises, within the context of the present invention, the linear polymer comprising the polymeric unit described above, according to a sequence with alternating β(<NUM>,<NUM>) and β(<NUM>,<NUM>) glycosidic bonds, having a molecular weight (MW) which may vary between <NUM> and <NUM><NUM><NUM> daltons. This molecular weight mainly depends on the source from which the hyaluronic acid is obtained and/or the preparation methods.

The production of hyaluronic acid by bacteria has been known for more than <NUM> years, with the most commonly used microorganisms in this context being bacteria of the genus Streptoccocus, in particular those of the serological groups A (Streptococcus pyogenes) and C (Streptococcus equi) (Lancefield grouping).

The production of hyaluronic acid from cultures of recombinant microorganisms such as Bacillus subtilis (Brown and Pummill, <NUM>; Chien and Lee, <NUM>), Escherichia Coli (Yu and Stephanopoulos, <NUM>) and Lactococcus lactis (Chien and Lee, <NUM>) is also known.

After fermentation and various treatment steps (dilution, filtration, ethanol precipitation), crude hyaluronic acid is obtained.

A hyaluronic acid salt according to the invention is especially an alkali metal salt and may in particular be chosen from sodium hyaluronate and potassium hyaluronate.

A hyaluronic acid or a salt thereof according to the present invention especially has a molecular weight of between <NUM> kDa and <NUM> kDa, in particular between <NUM> kDa and <NUM> kDa.

A hyaluronic acid or a salt thereof according to the invention may especially be provided:.

The hyaluronic acid or a salt thereof is present in the composition in a dry matter content of between <NUM>% and <NUM>% by weight, in particular between <NUM> and <NUM>% by weight, and even more particularly between <NUM> and <NUM>% by weight relative to the total weight of the composition.

An acrylic polymer in accordance with the present invention is constituted of, a crosslinked homopolymer of acrylic acid.

The homopolymer may be crosslinked with a crosslinking agent, chosen especially from pentaerythrityl allyl ether, sucrose allyl ether and propylene allyl ether.

Such polymers have the INCI name: Carbomer.

Therefore, the present invention in particular concerns a composition comprising hyaluronic acid or a salt thereof, spring and/or mineral water in a content greater than <NUM>% by weight relative to the total weight of the composition, and at least a homopolymer of crosslinked acrylic acid.

An acrylic acid polymer according to the present invention may especially be provided:.

A copolymer of acrylic acid and of alkylacrylate is defined as being a copolymer of (i) monomer of the following formula (I):
<CHM>.

In this polymer, the monomer (I) constitutes the hydrophilic unit and the monomer (II) constitutes the hydrophobic unit.

(C<NUM>-C<NUM>)Alkyl esters of unsaturated carboxylic acids comprise, for example, lauryl (meth)acrylate, stearyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate and dodecyl (meth)acrylate.

Anionic polymers of this type are described and prepared, for example, according to patents <CIT> and <CIT>.

Among this type of anionic polymers, use will more particularly be made of polymers formed from a mixture of monomers comprising:.

Among this type of anionic polymers, use will more particularly be made of those constituted of from <NUM> to <NUM>% by weight of acrylic acid (hydrophilic unit), <NUM> to <NUM>% by weight of C<NUM>-C<NUM> alkyl acrylate (hydrophobic unit) and <NUM> to <NUM>% by weight of crosslinking polymerizable monomer, or alternatively those constituted of from <NUM> to <NUM>% by weight of acrylic acid (hydrophilic unit), <NUM> to <NUM>% by weight of C<NUM>-C<NUM> alkyl acrylate (hydrophobic unit) and <NUM> to <NUM>% by weight of crosslinking polymerizable monomer such as those described above.

Said above polymers may especially be provided:.

According to the present invention, preference is most particularly given, as acrylic acid polymers or copolymers of acrylic acid and of alkylacrylate, to the products sold by Lubrizol under the trade names CARBOPOL <NUM>, <NUM> and by 3V under the trade name SYNTHALEN K.

The acrylic acid polymer, the copolymer of acrylic acid and of alkylacrylate or a mixture thereof is present in the composition in a dry matter content of between <NUM>% and <NUM>%, in particular between <NUM> and <NUM>% by weight, and even more particularly between <NUM> and <NUM>% by weight relative to the total weight of the composition.

According to a particular embodiment of the invention, the composition comprises water of the Vichy basin in a content greater than <NUM>% by weight relative to the total weight of the composition, sodium hyaluronate and an acrylic polymer.

The composition of the present invention is in the form of a gel and even more in the form of a transparent gel.

According to a particular embodiment, the composition according to the present invention is free of base, and more precisely is free of an additional base.

According to a particular embodiment, the composition according to the present invention may also contain an organic acid.

Indeed, according to a particular embodiment of the invention, the composition has a pH which may be between <NUM> and <NUM>.

Among these acids, mention may especially be made of citric acid, salicylic acid and derivatives thereof (LHA), lactic acid and mixtures thereof.

According to an even more preferred embodiment, the composition according to the present invention also comprises citric acid.

The additional active agents for cosmetic treatment of keratin materials, such as the skin, of use in the compositions of the invention may especially be chosen from desquamating agents, antimicrobial agents, soothing agents, antioxidants, astringents, anti-aging agents, firming agents, anti wrinkle agents, moisturizers, and mixtures thereof.

The composition of the invention more particularly constitutes a moisturizing and/or anti-aging, in particular antiwrinkle, facial care composition. It may nonetheless, as a variant, constitute a body care composition.

The composition of the invention may constitute a fortifying and hydrating daily skin booster.

The composition may also help to soothe and strengthen the skin against external aggressors and namely contribute to fortify and make the skin more resistant to help protect it against external aggressors like pollution and cold weather.

The composition according to the present invention may be applied daily on the skin.

After a few weeks of daily use, it may be observed that the skin is more hydrated and appears plumped and toned. As a whole, the skin appears with an improved healthy-looking glow.

The additional, advantageously hydrophilic active agent(s) may be present in the composition according to the invention in a content ranging from <NUM>% to <NUM>% by weight, preferably ranging from <NUM>% to <NUM>% by weight and preferentially ranging from <NUM>% to <NUM>% by weight relative to the total weight of the composition.

According to a variant, the composition according to the invention may be a care composition, especially a skincare product such as a care gel (day care, night care, anti wrinkle care) or else a care mask.

A composition according to the invention may also contain one or more colorants, of water-soluble pigment or dye type.

The composition according to the invention may also comprise adjuvants that are common in the cosmetics and dermatology fields, such as fragrances and preservatives. The amounts of these various adjuvants are those conventionally used in the fields under consideration, and for example from <NUM>% to <NUM>% of the total weight of the composition.

Needless to say, those skilled in the art will take care to select the optional compound(s) to be added to the compositions according to the invention and also the concentration thereof, such that the advantageous properties intrinsically associated with the compositions in accordance with the invention are not, or are not substantially, adversely affected by the envisioned addition.

Throughout the description, including the claims, the term "comprising a" should be understood as being synonymous with "comprising at least one", unless otherwise specified.

The terms "between. " and "ranging from. " should be understood as being inclusive of the limits, unless otherwise specified.

In the description and the examples, the percentages are percentages by weight, unless otherwise indicated. The percentages are thus given by weight relative to the total weight of the composition. The ingredients are mixed in the order and under the conditions that are easily determined by those skilled in the art.

The viscosity was measured with a Lamy Rheomat RM100. The measurements are given in UD and measured with spindles <NUM> (M3) or <NUM> (M2).

Procedure: The aqueous gel is prepared under cold conditions with stirring. The addition of the phase E (citric acid) into the phase A (aqueous phase) precedes the addition of the glycols. The Carbomer is added last. The citric acid may be added either into the aqueous phase or at the end of formulation. The sodium hyaluronate may be introduced at the same time as the carbomer.

The viscosity was also measured:
Viscosity Pa. s (Poise) T0-T10 min <NUM> UD (M3 = <NUM> Pa. s (<NUM> poise) <NUM> UD (M3) = <NUM> Pa. s (<NUM> poise).

The present aqueous gel may be prepared according to the protocol described in example <NUM>.

The viscosity was also measured:
Viscosity T0/T10 min <NUM> UD (M4) = <NUM> Pa. s (<NUM> poises) /<NUM> UD (M4) = <NUM> Pa. s (<NUM> poises).

The viscosity was also measured:
Viscosity T0/T10 min <NUM> UD (M2) = <NUM> Pa. s (<NUM> cps) cps/ <NUM> UD (M2) = <NUM> Pa. s (<NUM> cps).

The gels obtained in examples <NUM> to <NUM> above all have satisfactory stability. No phase separation was thus observed, nor the appearance of crystals, which may be observed when mixing hyaluronic acid with a spring and/or mineral water when the content thereof exceeds especially <NUM>% and even more so <NUM>% by weight relative to the total weight of the composition employing same.

Claim 1:
A composition comprising hyaluronic acid or a salt thereof, spring and/or mineral water in a content greater than <NUM>% by weight relative to the total weight of the composition, and at least one acrylic acid polymer, a copolymer of acrylic acid and of alkylacrylate, or one of the mixtures thereof, wherein the composition is in a single phase, and wherein it is provided in the form of a gel, characterized in that the gel is transparent, wherein the hyaluronic acid or a salt thereof is present in a dry matter content of between <NUM>% and <NUM> % by weight relative to the total weight of the composition,
wherein the acrylic acid polymer is a homopolymer of crosslinked acrylic acid and the copolymer of acrylic acid and of alkylacrylate is chosen from the copolymers of (i) monomer of the following formula (I):
<CHM>
wherein R<NUM> denotes H or CH<NUM> or C<NUM>H<NUM>, and of (ii) monomer of the following formula (II):

        H<NUM>C=CR<NUM>-COOR<NUM>     (II)

wherein R<NUM> is same as or different from that in formula (I), denotes H or CH<NUM> or C<NUM>H<NUM>, R<NUM> denotes a C<NUM>-Ca<NUM>, alkyl group,
wherein the acrylic acid polymer, the copolymer of acrylic acid and of alkylacrylate or a mixture thereof is present in the composition in a dry matter content of between <NUM>% and <NUM>% by weight, relative to the total weight of the composition.