WO2025104095A1 - Aqueous composition for preparing a peelable mask - Google Patents

Abstract

The invention relates to an aqueous composition for preparing a peelable non-therapeutic cosmetic mask comprising two separate mixtures brought into contact when they are applied to an individual. The invention also relates to a cosmetic care method using the composition, to a kit for preparing a peelable mask and to a method for preparing the aqueous composition.

Description

Description

Title of the invention: Aqueous composition for the preparation of a peel-off mask

[0001] The invention relates to an aqueous composition for the preparation of a peel-off non-therapeutic cosmetic mask comprising two distinct mixtures brought into contact during their application to an individual. The invention also relates to a cosmetic care method using said composition, a kit for preparing a peel-off mask and a method for preparing the aqueous composition.

[0002] The invention is in the field of cosmetics and dermatology. It finds a particularly advantageous application in the field of skin care.

Previous Art

[0003] Products for topical application of the mask type are well known in the cosmetic and dermatological fields. They are presented in particular in the form of impregnated fabrics, or emulsions, gels or pastes, which can be removed by wiping or peeling.

[0004] During the application time, the occlusive effect of the mask allows the horny layer to hydrate and soften, which can promote the penetration of substances having biological or pharmacological activity, in the case where one or more active substances are included in the composition.

[0005] Various mask formulas are described in the literature, for example in "Cosmetic and Toiletry Formulations", Second Edition, Ernest W. Flick 1992.

[0006] Masks in the form of emulsions, gels or pastes, which can be removed by wiping, may have the disadvantage of having to be eliminated at the end of the application time, sometimes requiring tedious handling, such as wiping and washing the skin; especially since the composition of the mask has been designed to strengthen its adhesion to the skin.

[0007] Impregnated masks do not have this disadvantage, since they rely on the use of a support, textile or other, thus allowing the removal of the mask in a simple operation. However, to be effective, the support of impregnated masks must perfectly match the contours and morphology of the part of the body to be treated, which limits their application possibilities, compared to masks in the form of creams.

[0008] There are also aqueous film-forming compositions based on polyvinyl alcohol which form masks which can be peeled off. These peel-off masks dry after application to the face to form a homogeneous plastic film whose mechanical consistency is sufficient to allow the film to be removed by tearing without tearing it. These masks have the advantage of providing good occlusion.

[0009] However, removing these masks can be harsh on the skin, making their use prohibitive. Furthermore, the presence of petrochemical compounds such as polyvinyl alcohol in their composition makes them unsuitable for natural formulations.

[0010] Aqueous film-forming compositions based on water-soluble polymers of natural origin such as alginates are also known, which form masks which can be removed by peeling.

[0011] The advantages of alginates in topical application to promote the cutaneous penetration of substances having biological or pharmacological activity are known. Patent EP 0888769 describes several compositions using alginate lyophilisates and whose moisturizing, nourishing, restructuring and firming properties have been described.

[0012] Several patents also describe their use in compositions capable of forming homogeneous plastic films for topical application of the “peel-off” mask type.

[0013] In the latter case, the formation of the homogeneous plastic film is obtained thanks to the crosslinking reaction of an alkaline alginate salt polymer by a source of calcium in solution in the ionic state Ca2+.

[0014] Patent EP0045493 describes such a composition intended for the preparation of a cosmetic mask, comprising an alginate, a bivalent metal salt (calcium ion Ca2+), a phosphate, an anionic surfactant and a filler such as SiO2, or ZnO, or Al203.

[0015] In this patent application, the crosslinking agent is incorporated into a dehydrated alginate composition. The dry form of the composition does not allow the crosslinking reaction, which must take place in an aqueous medium, to start. A retarder (phosphate) allows the user to have sufficient time to rehydrate the composition and apply it to the skin, before the polymer crosslinks and the film forms.

[0016] The crosslinking agent (the calcium ion Ca ²⁺ ) being previously incorporated into the alginate mass, this solution has the advantage of leading to homogeneous crosslinking of the polymer mass, which leads to good mechanical strength of the film thus obtained.

[0017] However, the significant proportion of mineral substances in the composition, resulting from the need to incorporate a retarder into the composition, limits the crosslinking reaction of the alginate polymer. It is therefore necessary to apply the mask in a thick layer to obtain sufficient mechanical strength to allow the film to be removed in one go by peel-off effect.

[0018] Furthermore, the need to have a suitable container and the preparation time- ration of the material by rehydration of the composition under agitation can limit the distribution of such a product to the general public.

[0019] Patent WO 2012095567 proposes an improvement by adding to the composition to be rehydrated a powder fluidizer facilitating the mixing of the dehydrated preparation with the water necessary for the formation of the gel. However, this composition does not eliminate the need to rehydrate the composition before application.

[0020] Patent WO 1990002774 describes the crosslinking of a mask composed, among other things, of an aqueous sodium alginate gel by spraying a 10% aqueous solution of calcium chloride (CaCl2) onto the surface of the alginate gel once applied to the skin.

[0021] Spraying an aqueous solution of CaCh to cause crosslinking of an aqueous gel composed of alkali metal alginate is advantageous because the film-forming preparation can then be rehydrated in advance and presented to the user in the form of a ready-to-use gel.

[0022] However, CaCh solutions are irritating to the skin and eyes, which requires the user to close their eyes during spraying. This can compromise the good distribution of the spray on the gel layer and limit the interest of this solution among the public.

[0023] Furthermore, since the diffusion of CaCh through the alginate polymer layer is not homogeneous, the plastic film thus formed may lack mechanical coherence in places, which makes it difficult to remove because the film breaks when removed and the removal must therefore be done in several stages.

[0024] Spraying other calcium salts that are less irritating to the eyes, such as calcium lactate solution, has been tested. However, the lower reactivity of calcium lactate makes crosslinking of the alginate gel even less effective. And it has been found that the film obtained after crosslinking is fragile and can tear when peeled off the skin.

[0025] Furthermore, the rehydrating compositions of the prior art must incorporate an agent sequestering alkaline-earth ions, generally a phosphate, to avoid untimely crosslinking of the gel during rehydration of the mixture of alginate and carbonate, in order to give the user sufficient time to apply the mixture to the skin.

[0026] Thus, there remains a need for a peel-off occlusive mask that does not have the drawbacks of those of the prior art, and there is currently no composition for topical application based on alginates that allows successive application of two mixtures on top of each other by crosslinking the surface of the first. Furthermore, there is currently no composition for topical application based on alginates that allows immediate application, without prior mixing in a suitable container of two components, or without rehydration of dehydrated powders. [0027] Surprisingly, the Applicant has demonstrated a new composition for topical application, presented in the form of two aqueous mixtures, usable by a single person, quickly and simply and without external assistance.

Description of the invention

[0028] Thus, according to a first aspect, the invention relates to an aqueous composition for the preparation of a peelable non-therapeutic cosmetic mask comprising:

- A first mixture comprising: i. An alginate gel of at least one alkali metal; ii. At least one salt of an alkaline earth metal insoluble at basic or neutral pH;

- A second mixture comprising: i. At least one soluble salt of an alkaline earth metal; ii. At least one acidifying compound.

[0029] The first aqueous mixture according to the invention comprises at least one basifying compound, so as to avoid the solubilization of the salt of the metal used with release of the corresponding alkaline-earth ions, and the crosslinking of the alginate gel which would follow.

[0030] The inventors have discovered that in order to make the salt of an alkaline earth metal insoluble at basic or neutral pH used inactive with respect to the crosslinking of the alginate, it is advisable to maintain the pH of the first mixture at an optimal value between 8 and 9, preferably between 8.5 and 9. This is obtained by adding at least one basifying compound to the first mixture.

[0031] The second aqueous mixture according to the invention is maintained at an acidic pH thanks to said at least one acidifying compound.

[0032] This composition combines two aqueous mixtures forming a homogeneous and coherent plastic film once applied one after the other to the skin of an individual, said film being able to be removed without tearing by peeling.

[0033] Preferably, said alginate of at least one alkali metal is present in a concentration of between 0.5% and 10% by total weight of the composition of the first mixture, preferably between 2% and 4%, even more preferably 3%.

[0034] According to one embodiment, said alkali metal alginate is chosen from sodium alginate, potassium alginate, or a mixture thereof.

[0035] Preferably, said alkali metal alginate gel is sodium alginate. Even more preferably, said sodium alginate is present in a concentration of between 0.5% and 10% by total weight of the composition of the first mixture, preferably between 2% and 4%, even more preferably 3%.

[0036] Even more preferably, said salt of an alkaline earth metal insoluble at basic or neutral pH is present in a concentration of between 0.1% and 5% by total weight of the composition of the first mixture, preferably between 0.2% and 2%, even more preferably 0.5%.

[0037] According to one embodiment, said salt of an alkaline earth metal insoluble at basic or neutral pH is chosen from calcium sulfate, calcium carbonate, or a mixture thereof.

[0038] Preferably, said salt of an alkaline earth metal insoluble at basic or neutral pH is calcium carbonate.

[0039] Even more preferably, said calcium carbonate is present in a concentration of between 0.1% and 5% by total weight of the composition of the first mixture, preferably between 0.2% and 2%, even more preferably 0.5%.

[0040] More preferably, the source of calcium carbonate is organic. Said organic source may be pearl powder or oyster shell powder.

[0041] Even more preferably, said oyster shell powder has a particle size of between 0.1 and 500 μm, even more preferably between 0.01 and 30 μm.

[0042] Preferably, said first mixture comprises at least one basifying compound.

[0043] According to one embodiment, said basifying compound is chosen from sodium hydroxide, potassium citrate, triethanolamine, or a mixture thereof.

[0044] The cited presence of the "basifying compound" takes into account the possibility of varying the choice of the components of the formula, and in particular the source of calcium. Alternatively, due to the nature of the ingredients, the formula already has a slightly basic pH, with the calcium carbonate raising the pH above 8.

[0045] Said basifying compound is present in sufficient quantity to achieve the optimal pH condition for the proper functioning of the invention.

[0046] Preferably, said basifying compound is present in a concentration of between 0.1% and 5% by total weight of the composition of the first mixture, preferably between 0.5% and 2%.

[0047] According to one embodiment, the second mixture comprises between 0.5% and 10%, preferably between 2% and 7%, by weight of the second mixture of said soluble salt of an alkaline earth metal.

[0048] According to one embodiment, said soluble salt of an alkaline earth metal is selected from calcium chloride, calcium lactate, calcium gluconate or a mixture thereof.

[0049] Preferably, said acidifying compound is present between 0.1% and 10%, preferably between 3.5 and 8.5%, even more preferably 6%, by weight of the second mixture.

[0050] According to one embodiment, said acidifying compound is chosen from phytic acid, citric acid, malic acid, glycolic acid, gluconodeltalactone or a mixture thereof.

[0051] Preferably, said acidifying compound is a mixture of phytic acid and gluconolactone. Even more preferably, the second mixture comprises between 0.5% and 1.5%, preferably 1% by weight of the second mixture of phytic acid, and between 3% and 7%, preferably 5% by weight of the second mixture of gluconodeltalactone.

[0052] Said at least one acidifying compound makes it possible to dissociate said salt of an alkaline-earth metal insoluble at basic or neutral pH from the first mixture and thus to release Ca ²⁺ ions into the first mixture, when applying the second mixture to the first on the user's skin.

[0053] According to one embodiment, the two mixtures may comprise at least one preservative, preferably between 1% and 10% by weight of each of the mixtures.

[0054] According to one embodiment, the first mixture may also comprise water-soluble polymers.

[0055] The addition of certain polysaccharides to this mixture makes it possible to improve the mechanical consistency of the plastic film obtained.

[0056] Preferably, said polysaccharides are of natural origin.

[0057] Even more preferably, said polysaccharides are chosen from pulullane, carrageenans, gum arabic, guar gum, Tara gum or one of their mixtures.

[0058] Even more preferably, said polysaccharides are present in a proportion ranging from 0.1% to 5%, preferably between 0.5 and 3%, even more preferably 1.4%, by weight of the first mixture.

[0059] According to one embodiment, the first mixture comprises a mixture of pulullane, gum arabic and carrageenan.

[0060] Preferably, this first mixture comprises 0.5% by weight of the first mixture of pulullane, 0.5% by weight of the first mixture of gum arabic and 0.4% by weight of the first mixture of carrageenan.

[0061] The addition of certain polyols to this mixture makes it possible to improve the plasticity of the plastic film obtained.

[0062] The plasticity and mechanical consistency characteristics of the film are important because they determine the ability of the plastic film to be torn off in one piece without tearing. [0063] Preferably, said polyol may be chosen from erythritol, sorbitol, mannitol, or xylitol, or one of their mixtures.

[0064] Even more preferably, said polyols are present in a proportion ranging from 0.1% to 10%, preferably between 0.5% and 5%, even more preferably 1%, by weight of the first mixture.

[0065] Even more preferably, said polyol is erythritol present at 1% of the total weight of the first mixture.

[0066] According to one embodiment, said first mixture may also comprise organic or mineral fillers intended to opacify the plastic film obtained by crosslinking the film-forming polymer.

[0067] Preferably, said fillers are opacifiers conventionally used in the cosmetic field of topical applications, such as titanium dioxide, rice starch, talc, kaolin, or one of their mixtures.

[0068] According to one embodiment, said fillers comprise a mixture of rice starch and kaolin, in equal parts, representing between 0.5 and 10%, preferably between 1% and 5%, even more preferably 4% of the total weight of the mixture 1.

[0069] According to one embodiment, the mixture 1 may also comprise other cosmetically acceptable active compounds. Any active compound may be used in the invention provided that it is compatible with the film-forming hydrophilic polymer used in the first mixture, in particular sodium alginate.

[0070] Such active ingredients may include in particular the following categories of ingredients: vitamins, healing agents, anti-aging, anti-wrinkle, soothing or antioxidant agents, anti-free radical or anti-UV agents, agents stimulating the synthesis of dermal macromolecules or energy metabolism, moisturizing, antibacterial, antifungal, anti-inflammatory, anesthetic agents, agents modulating cell differentiation, pigmentation or skin depigmentation.

[0071] A person skilled in the art will ensure that these active ingredients and their proportions are chosen in such a way as not to harm the advantageous properties of the composition according to the invention. The total proportion of these active ingredients may, for example, be between 0.01 and 10% of the total weight of the composition (of mixture 1 and/or of mixture 2).

[0072] According to one embodiment, said aqueous composition for the preparation of a peelable non-therapeutic cosmetic mask comprises:

- A first mixture comprising: i. Between 0.5% and 10% by weight of the first mixture of an alginate gel of at least one alkali metal; ii. Between 0.1% and 5% by weight of the first mixture of at least one salt of an alkaline earth metal insoluble at basic or neutral pH; iii. Between 0.1% and 5% by weight of the first mixture of at least one basifying compound;

- A second mixture comprising: i. Between 0.5% and 10% by weight of the second mixture of at least one soluble salt of an alkaline earth metal; ii. Between 0.1% and 10% by weight of the second mixture of at least one acidifying compound.

[0073] According to one embodiment, an example of a first mixture is the following (by weight of the first mixture):

- Demineralized water: qsp 100%

- Sodium alginate: 3%

- Carrageenan: 0.4%

- Pulullane: 0.5%

- Gum arabic: 0.5%

- Erythritol: 1%

- Rice starch: 3%

- Clay: 0.5%

- Kaolin: 0.5%

- Calcium carbonate: 0.5%

- Conservative

[0074] Embodiment without gelling agent

[0075] According to one embodiment, said second mixture does not comprise a gelling agent.

[0076] In this embodiment, the second mixture comprises as soluble salt of an alkaline earth metal of calcium chloride, between 0.5% and 10%, preferably between 3% and 7%, even more preferably 5%, by weight of the second mixture.

[0077] In one embodiment, the second mixture comprises calcium lactate, between 0.5% and 10%, preferably between 3% and 7%, even more preferably 5%, by weight of the second mixture.

[0078] According to one embodiment, an example of a second mixture according to this embodiment is as follows (by weight of the second mixture):

- Demineralized water: qsp 100%

- Calcium lactate: 5%

- Gluconodeltalactone: 5% - Phytic acid: 1%

- Conservative

[0079] Gelling embodiment

[0080] According to an alternative embodiment, said second mixture comprises a gelling agent.

[0081] The addition of this gelling agent has the advantage of forming an aqueous gel with suitable pseudo-plastic properties.

[0082] Preferably, said gelling agent is chosen from polymers of natural or synthetic origin.

[0083] Even more preferably, said polymers are chosen from: carboxyvinyl polymers resulting from the association of vinyl acid molecules, acrylic copolymers such as acrylate-alkylacrylate copolymers, polyacrylamides, cellulose derivatives such as carboxymethylcellulose, optionally modified polysaccharides such as hydroxypropylcellulose, or polysaccharides derived from natural raw materials, such as carrageenans, guar gum, carob gum, scleroglucan, cellulose, dehydroxanthan gum, tara gum or xanthan gum, or a mixture thereof.

[0084] According to one embodiment, said gelling agent is a hydrophilic polymer having the property of forming an aqueous gel with suitable pseudo-plastic properties.

[0085] According to one embodiment, said gelling agent is Carbopol® or SynerGX®.

[0086] SynerGX® includes guar gum and xanthan gum.

[0087] According to one embodiment, said gelling agent comprises SynerGX® and carrageenan. More preferably, the second mixture comprises 1.3% SynerGX® and 1.5% carrageenan.

[0088] Carbopol® comprises carboxyvinyl polymers.

[0089] In this embodiment, the second mixture comprises as soluble salt of an alkaline earth metal of calcium chloride, between 0.5% and 10%, preferably between 2% and 5%, by weight of the second mixture.

[0090] In one embodiment, the second mixture comprises calcium lactate, between 0.5% and 10%, preferably between 3% and 7%, even more preferably 5%, by weight of the second mixture.

[0091] According to one embodiment, an example of a second mixture according to this embodiment is as follows (by weight of the second mixture):

- Demineralized water: qsp 100%

- Calcium lactate: 5%

- Carrageenan: 0.5%

- SynerGX® (Guar Gum and Xanthan Gum): 1% - Gluconodeltalactone: 5%

- Phytic acid: 1%

- Conservative

[0092] According to a second aspect, the invention relates to a non-therapeutic cosmetic care method for the skin of an individual, comprising the application of an aqueous composition according to the invention in order to obtain a peel-off mask, via the successive steps of:

- Application to the skin of said individual of the first mixture;

- Application on the first mixture applied to the skin of said individual of the second mixture.

[0093] Preferably, the skin of the individual is the skin of the face.

[0094] According to one embodiment, when the second mixture does not comprise a gelling agent, this second mixture can be applied by spraying.

[0095] The successive application in a thin layer on the skin has the property of forming a coherent plastic film, thanks to a simple process, easy to adjust, without the use of toxic or irritating substances.

[0096] The two mixtures are applied successively, one on top of the other, to the skin and then form a coherent and homogeneous plastic film, which can be easily removed by peeling, or “peel-off” effect.

[0097] Thanks to the characteristics of the composition according to the invention, this application method allows a single person to apply the mask according to the invention to the skin, more particularly to the face, easily and without external assistance.

[0098] According to one embodiment, the first mixture is applied to the individual's skin with the fingers, or using a suitable utensil (brush or spatula) in order to form a uniform layer of gel with a thickness of a few tenths (a few millimeters) on the skin.

[0099] Preferably, the second mixture is applied immediately after application of the first mixture, on the layer of the first mixture previously applied to the individual's face.

[0100] Thanks to the characteristics of the composition according to the invention, the application of the second mixture on the layer of the first mixture, with the fingers or with any other application utensil such as a spatula or a brush, does not destroy the layer of the first mixture by scraping its surface.

[0101] It is thus observed that, on the one hand, the crosslinking reaction of the alginate occurs instantly upon contact with the ions of an alkaline earth metal present in the second mixture; on the other hand, this reaction is localized at the surface of the gel.

[0102] The surface of the gel then hardens sufficiently to allow the fingers to slide over the gel layer without destroying it, which facilitates the application and spreading in a thin layer of the second mixture over the entire surface of the gel of the first mixture.

[0103] According to one embodiment, following the application of the second mixture, the individual leaves it to stand for between 1 and 30 minutes, preferably between 5 and 15 minutes, even more preferably 10 minutes.

[0104] Under the effect of the acidifying agent contained in the second mixture, the pH of the gel layer decreases, which causes the dissociation of the alkaline earth metal salt present in the gel and the release of the corresponding ions throughout the mass of the gel. This then leads to the endogenous and in-depth crosslinking of the entire mass of alginate in the first mixture.

[0105] This process thus leads to the complete plasticization of the first layer of gel (corresponding to the first mixture), to form a coherent, homogeneous and continuous plastic film, with sufficient mechanical characteristics to allow the film to be removed in one piece by peel-off effect.

[0106] Indeed, in the first mixture, the alkaline earth metal salt being incorporated homogeneously into the alginate, the crosslinking reaction is very effective. This leads to the production of a plastic film of good mechanical quality, thus promoting the removal of the film without tearing and the expected “peel-off” effect.

[0107] Thus, according to one embodiment, in the case of the second mixture comprising a gelling agent, the successive implementation steps may be as follows:

- Spread the first mixture in a thick layer on the skin;

- Spreading the second mixture on the first mixture: The rapid crosslinking of the alginate contained in the first mixture under the effect of the Ca2+ ions of the second mixture is localized at the contact surface of the two gels. It allows the second mixture to be spread and smoothed into a thin layer, without destroying the layer of the first gel;

- Deep crosslinking reaction of the first mixture: Under the effect of the drop in pH in the first mixture (due to the acidifying agent present in the second mixture) the calcium carbonate present in the first mixture solubilizes and releases the Ca2+ ions. The deep crosslinking of the alginate then occurs gradually throughout the entire layer of the first mixture.

- Complete plasticization and formation of a homogeneous film: At the end of the reaction, the entire layer of the first mixture is plasticized and can be removed by peeling or “peel-off” effect.

[0108] According to another embodiment, in the case of the second mixture without gelling agent, the successive implementation steps may be as follows:

- Spread the first mixture in a thick layer on the skin; - Spraying the second mixture onto the first mixture: Rapid crosslinking of the surface of the alginate contained in the first mixture under the effect of the Ca2+ ions of the second mixture;

- Deep crosslinking reaction of the first mixture: Under the effect of the drop in pH in the first mixture (due to the acidifying agent present in the second mixture) the calcium carbonate present in the first mixture solubilizes and releases the Ca2+ ions. The deep crosslinking of the alginate then occurs gradually throughout the entire layer of the first mixture.

- Complete plasticization and formation of a homogeneous film: At the end of the reaction, the entire layer of the first mixture is plasticized and can be removed by peeling or “peel-off” effect.

[0109] According to one embodiment, the non-therapeutic cosmetic care method for the skin of an individual comprises, before the step of applying the first mixture to the skin of the face of said individual, a step of applying a cosmetic composition aimed at preparing the skin.

[0110] The effectiveness of preparations for topical application is improved by adequate preparation of the skin.

[0111] Preferably, said cosmetic composition aimed at preparing the skin is a composition which gives the skin improved permeability to the active cosmetic ingredients of the aqueous non-therapeutic cosmetic for the preparation of a peel-off mask.

[0112] Even more preferably, this cosmetic composition aimed at preparing the skin may comprise ingredients chosen from: surfactants, keratolytic agents, or even humectants.

[0113] According to one embodiment, the non-therapeutic cosmetic care method for the skin of an individual comprises, before the step of applying the first mixture to the skin of the face of said individual, a step of applying a cosmetic composition comprising cosmetic active ingredients.

[0114] Such cosmetic active ingredients are the same active compounds known to those skilled in the art and which can also be included in the composition according to the invention.

[0115] In the case where a preparation step is present, this step of applying a cosmetic composition comprising cosmetic active ingredients is carried out between the step of preparing the skin and the step of applying the first mixture according to the invention.

[0116] This cosmetic composition comprising cosmetic active ingredients is preferably in the form of a lotion, serum or aqueous gel.

[0117] The cosmetic care process according to the invention can be repeated as many times as necessary by the individual.

[0118] Indeed, for certain cosmetic applications, it is advantageous to combine the periodic application, for example biweekly, of the compositions according to the invention with, on the one hand, the daily application of a topical application preparation of the “day care” type, in which the same cosmetic active ingredients or those present in the composition according to the invention are incorporated, and/or on the other hand the application of a topical application preparation of the “night care” type, in which these same cosmetic or pharmacological active ingredients are present.

[0119] According to a third aspect, the invention relates to a kit for preparing a peel-off mask comprising an aqueous composition for preparing a peel-off non-therapeutic cosmetic mask according to the invention, comprising the first mixture and the second mixture.

[0120] The mixtures according to the present invention can in fact be provided in a preparation kit composed of two containers, the contents of which can be applied successively to the skin. These containers can be chosen from tubes, bottles, pots. The containers preferably have a volume of between 15 and 300 mL.

[0121] The invention also allows the packaging of the two mixtures according to the invention in single-dose containers. These containers can advantageously be chosen in a non-limiting manner from the single-dose containers usually used in cosmetics, such as sachets, cartons, disposable capsules, or even “twist-off” tubes. The single-doses preferably have a volume of between 5 and 30 mL.

[0122] According to a fourth aspect, the invention relates to a process for preparing the aqueous composition according to the invention comprising:

- In order to prepare the first mixture, the successive steps of: i. Solubilization in water of said alkali metal alginate at room temperature, with medium stirring; ii. Once the alginate is completely dissolved, addition of said basifying compound in order to adjust the pH above 6; iii. Once the pH has stabilized, said salt of an alkaline earth metal insoluble at basic or neutral pH is added to the mixture, at room temperature and with medium stirring;

- In order to prepare the second mixture, the successive steps of: i. Heating a volume of water to 70°; ii. Adding said soluble salt of an alkaline earth metal to said volume of water; iii. After complete dissolution of said soluble salt of an alkaline earth metal in water, the mixture is left to cool with moderate stirring to room temperature. iv. Adding said acidifying compound to said mixture; v. Letting said mixture stand until the pH stabilizes between 2 and 4, preferably between 3.2 and 3.6, and until a homogeneous mixture is obtained; vi. Once the pH has stabilized and the mixture is homogeneous, the solution is then ready to be packaged in a spray bottle.

[0123] Preferably, the average agitation is between 500 and 2000 rpm, preferably 800 rpm.

[0124] According to one embodiment, between step i. and step ii. of the first mixture, once the alginate is completely dissolved, and still at room temperature and with moderate stirring, the mixture of water-soluble polymers intended to reinforce the mechanical properties of the plastic film obtained by crosslinking the film-forming polymer is added.

[0125] According to one embodiment, between steps i. and ii. of the first mixture, after the addition of said water-soluble polymers, it is advantageous to incorporate into the mixture the active ingredients and fillers, if any, provided in the formula and to mix the whole with moderate stirring until a homogeneous gel is obtained.

[0126] After adding the calcium source added and dispersed in the mixture, the pH will advantageously be 8 to 9.

[0127] In the gelling embodiment, said gelling agent is incorporated into water heated to 70°C with moderate stirring, before step i. of preparing the second mixture.

[0128] According to a fifth aspect, the invention relates to the use of the kit according to the invention for extemporaneously preparing a peel-off mask for the skin.

[0129] Preferably said mask is non-therapeutic cosmetic.

[0130] According to a sixth aspect, the invention relates to the use of an aqueous composition comprising:

- A first mixture comprising: i. An alginate gel of at least one alkali metal; ii. At least one salt of an alkaline earth metal insoluble at basic or neutral pH; iii. At least one basifying compound;

- A second mixture comprising: i. At least one soluble salt of an alkaline earth metal; ii. At least one acidifying compound; for the preparation of a peel-off non-therapeutic cosmetic mask.

[0131] According to a seventh aspect, the invention relates to an aqueous composition for use in the preparation of a peel-off mask comprising dermatological active ingredients, comprising:

- A first mixture comprising: i. An alginate gel of at least one alkali metal; ii. At least one salt of an alkaline earth metal insoluble at basic or neutral pH; iii. At least one basifying compound;

- A second mixture comprising: i. At least one soluble salt of an alkaline earth metal; ii. At least one acidifying compound.

[0132] According to an eighth aspect, the invention relates to a dermatological treatment method comprising:

- Application to the skin of the face of said individual of the first mixture;

- Application on the first mixture applied to the skin of the face of said individual of the second mixture.

[0133] One or more mixtures according to this aspect may comprise therapeutic active agents making it possible to treat a skin pathology by transcutaneous administration.

[0134] According to one embodiment, said therapeutic active ingredients make it possible to treat acne, psoriasis and/or eczema.

Figures

[0135] [Fig 1] is a diagram showing the spreading of the first mixture in a thick layer on the skin.

[0136] [Fig 2] is a diagram showing the spreading of the second gelled mixture on the first mixture.

[0137] [Fig 3] is a diagram representing the deep crosslinking reaction of the first mixture.

[0138] [Fig 4] is a diagram showing the complete plasticization and the formation of the homogeneous film.

[0139] [Fig 5] is a diagram showing the spraying of the second non-gelled mixture onto the first mixture.

Definitions

[0140] Alginates are extracted from the liquids of the cell wall of brown algae. They are polymers formed from two monomers: mannuronate or mannuronic acid, more or less acetylated, and guluronate or guluronic acid. Alginates have the ability to form viscous colloidal solutions, or gels, with water, whose rheological properties allow them to spread in a thin layer on the skin, with the fingers or with the help of a suitable utensil (brush or spatula). They also have the possibility of forming solid and homogeneous plastic films thanks to the crosslinking reaction of the alginate gel with an alkaline earth metal in solution in the ionic state. This crosslinking mechanism follows a kinetics which depends, among other things, on the availability of alkaline earth ions within the alginate gel.

[0141] By “aqueous composition” is meant that the composition in its form before use by an individual is a homogeneous mixture consisting mainly of water and other dissolved chemical species.

[0142] By "peel-off mask" or "peelable mask" is meant a mask applied to the face or other part of the skin of an individual, which dries on the skin after application, and which is then peeled off by the user. When this type of mask is removed, blackheads, dead cells, dirt and sebum deposits adhere to it. These masks are occlusive.

[0143] The alkali metals are lithium, sodium, potassium, rubidium, cesium and francium. In the context of the invention, sodium and potassium are preferably used.

[0144] Alkaline earth metals are beryllium, magnesium, calcium, strontium, barium and radium. Alkaline earth metals insoluble at basic or neutral pH are the salts of these metals which are soluble in water at pH greater than or equal to 7.

[0145] By "basifying compound" or "base" is meant a chemical product capable of capturing one or more protons or, conversely, of providing electrons. These products have a pH greater than 7, and have alkaline properties allowing the pH of the mixture to be raised.

[0146] By "acidifying compound" or "acid" is meant a chemical compound capable of giving up protons or, conversely, of capturing electrons. These products have a pH lower than 7, and have acidifying properties allowing the pH of the mixture to be lowered.

[0147] By “first mixture” and “second mixture” are meant distinct compositions comprising the indicated compounds. These mixtures are then brought into contact at the time of application to the individual’s skin.

[0148] By "room temperature" is meant a temperature corresponding to approximately 25°C at approximately a pressure of 100 kPa.

[0149] By “hydrophilic polymer having the property of forming an aqueous gel with suitable pseudo-plastic properties” is meant a water-soluble polymer forming a gel whose rheological properties allow it to be spread in a thin layer on the skin, with the fingers or with the aid of a suitable utensil (brush or spatula).

[0150] By topical application preparation of the “day care” and “night care” type is meant any form of topical application preparation, presented in in the form of an aqueous or hydroalcoholic solution, a water-in-oil or oil-in-water emulsion, a microemulsion, an aqueous or anhydrous gel, a serum, or even a dispersion of vesicles, a patch, a cream, a spray, an ointment, a salve, a lotion, a colloid, a solution, a suspension or other, and proposed for application to the skin, respectively in the morning upon waking, and in the evening before going to bed.

[0151] For the purposes of the invention, the term “non-therapeutic” means a cosmetic application not intended to treat a patient. In fact, the cosmetic use according to the invention does not act as a medicine for the treatment of diseases.

[0152] By “topical application” is meant, within the meaning of the present invention, an application to the skin (including the scalp) and the mucous membranes.

[0153] For the purposes of the present invention, the term “cosmetically acceptable” means that which is useful in the preparation of a cosmetic composition, which is generally safe, non-toxic and neither biologically nor otherwise undesirable and which is acceptable for cosmetic use, in particular by topical application to the skin.

[0154] By “cosmetically” effective quantity is meant a quantity making it possible to obtain the effects claimed according to the invention.

[0155] In the description and in the following examples, unless otherwise indicated, the percentages are percentages by weight and the ranges of values expressed in the form "between ... and ..." include the specified lower and upper limits. The examples below are presented for illustrative purposes and not as a limitation of the scope of the invention.

[0156] By “or a mixture thereof” is meant that each of the listed compounds may be mixed with one or more of the other compounds in the list.

Examples

[0157] Example 1: Test for obtaining a peel-off mask (gelled mixture 2)

[0158] In order to test the effectiveness of the peeling of the mask obtained using the composition according to the invention, 10 users are recruited in order to use the compositions according to the invention to form peelable masks on their faces.

[0159] To do this, they use the following mixtures:

[0160] First mixture (percentages by weight of the first mixture):

- Demineralized water: qsp 100%

- Sodium alginate: 3%

- Carrageenan: 0.4%

- Pulullane: 0.5%

- Gum arabic: 0.5%

- Erythritol: 1%

- Rice starch: 3% - Clay: 0.5%

- Kaolin: 0.5%

- Calcium carbonate: 0.5%

- Conservative

[0161] Second mixture (weight percentages of the second mixture):

- Demineralized water: qsp 100%

- Calcium lactate: 5%

- Carrageenan: 0.5%

- SynerGX® (Guar Gum and Xanthan Gum): 1%

- Gluconodeltalactone: 5%

- Phytic acid: 1%

- Conservative

[0162] The user thus carries out the successive implementation steps in order to obtain the peelable mask:

- Spreading the first mixture in a thick layer on the skin (Figure 1);

- Spreading the second mixture over the first mixture (Figure 2).

[0163] Thus, under the effect of the drop in pH in the first mixture (due to the acidifying agent present in the second mixture) the calcium carbonate present in the first mixture solubilizes and releases the Ca2+ ions. The deep crosslinking of the alginate then occurs gradually throughout the layer of the first mixture (Figure 3).

[0164] At the end of the reaction, the entire layer of the first mixture is plasticized and can be removed by peeling or “peel-off” effect (Figure 4).

[0165] After approximately 10 minutes of application on their faces, users seek to remove the peel-off mask.

[0166] All users reported that they had no difficulty removing the mask by hand, with the surface flaps being removed at least in large areas, or all at once, from the user's skin. No pain was reported by said users. Users did not need outside assistance to remove the mask.

[0167] Example 2: Test for obtaining a peelable mask (mixture 2 without gelling agent) [0168] In order to test the effectiveness of the peeling of the mask obtained using the composition according to the invention, 10 users are recruited in order to use the compositions according to the invention to form peelable masks on their faces.

[0169] To do this, they use the following mixtures:

[0170] First mixture (weight percentages of the first mixture):

- Demineralized water: qsp 100%

- Sodium alginate: 3%

- Carrageenan: 0.4%

- Pulullane: 0.5% - Gum arabic: 0.5%

- Erythritol: 1%

- Rice starch: 3%

- Clay: 0.5%

- Kaolin: 0.5%

- Calcium carbonate: 0.5%

- Conservative

[0171] Second mixture (weight percentages of the second mixture):

- Demineralized water: qsp 100%

- Calcium lactate: 5%

- Gluconodeltalactone: 5%

- Phytic acid: 1%

- Conservative

[0172] The user thus carries out the successive implementation steps in order to obtain the peelable mask:

- Spreading the first mixture in a thick layer on the skin (Figure 1);

- Spraying the second mixture onto the first mixture (Figure 5) [0173] Thus, under the effect of the drop in pH in the first mixture (due to the acidifying agent present in the second mixture) the calcium carbonate present in the first mixture solubilizes and releases the Ca2+ ions. The deep crosslinking of the alginate then occurs gradually throughout the layer of the first mixture (Figure 3).

[0174] At the end of the reaction, the entire layer of the first mixture is plasticized and can be removed by peeling or “peel-off” effect (Figure 4).

[0175] After approximately 10 minutes of application to their faces, users seek to remove the peel-off mask.

[0176] All users reported that they had no difficulty removing the mask by hand, with the surface flaps being removed at least in large areas, or all at once, from the user's skin. No pain was reported by said users. Users also did not need any outside help to remove their mask. Users did not need any outside help to remove the mask.

Claims

Claims [Claim 1] Aqueous composition for the preparation of a peel-off non-therapeutic cosmetic mask comprising: - A first mixture comprising: i. An alginate gel of at least one alkali metal; ii. At least one salt of an alkaline earth metal insoluble at basic or neutral pH; iii. At least one basifying compound; - A second mixture comprising: i. At least one soluble salt of an alkaline earth metal; ii. At least one acidifying compound. [Claim 2] An aqueous composition for the preparation of a peel-off non-therapeutic cosmetic mask according to the preceding claim, wherein said alkali metal alginate is selected from sodium alginate, potassium alginate, or a mixture thereof, preferably sodium alginate. [Claim 3] An aqueous composition for the preparation of a peel-off non-therapeutic cosmetic mask according to any one of the preceding claims, wherein said salt of an alkaline earth metal insoluble at basic or neutral pH is selected from calcium sulfate, calcium carbonate, or a mixture thereof, preferably calcium carbonate. [Claim 4] An aqueous composition for the preparation of a peel-off non-therapeutic cosmetic mask according to any one of the preceding claims, wherein said basifying compound is chosen from sodium hydroxide, potassium citrate, triethanolamine, or a mixture thereof. [Claim 5] An aqueous composition for the preparation of a peel-off non-therapeutic cosmetic mask according to any one of the preceding claims, wherein said soluble salt of an alkaline earth metal is selected from calcium chloride, calcium lactate, calcium gluconate or a mixture thereof. [Claim 6] An aqueous composition for the preparation of a peel-off non-therapeutic cosmetic mask according to any one of the preceding claims, comprising: - A first mixture comprising: i. Between 0.5% and 10% by weight of the first mixture of an alginate gel of at least one alkali metal; ii. Between 0.1% and 5% by weight of the first mixture of at least one salt of an alkaline earth metal insoluble at basic or neutral pH; iii. Between 0.1% and 5% by weight of the first mixture of at least one basifying compound; - A second mixture comprising: i. Between 0.5% and 10% by weight of the second mixture of at least one soluble salt of an alkaline earth metal; ii. Between 0.1% and 10% by weight of the second mixture of at least one acidifying compound. [Claim 7] An aqueous composition for the preparation of a peel-off non-therapeutic cosmetic mask according to any one of the preceding claims, wherein said second mixture comprises a gelling agent. [Claim 8] A method of non-therapeutic cosmetic care of the skin of an individual, comprising the application of an aqueous composition according to any one of the preceding claims in order to obtain a peel-off mask, comprising the successive steps of: - Application to the skin of the face of said individual of the first mixture; - Application on the first mixture applied to the skin of the face of said individual of the second mixture. [Claim 9] A kit for preparing a peel-off mask comprising an aqueous composition for preparing a peel-off non-therapeutic cosmetic mask according to any one of claims 1 to 7, comprising the first mixture and the second mixture. [Claim 10] A process for preparing the aqueous composition according to any one of claims 1 to 7 comprising: - In order to prepare the first mixture, the successive steps of: i. Solubilization in water of said alkali metal alginate at room temperature, with medium stirring; ii. Once the alginate is perfectly dissolved, addition of said basifying compound in order to adjust the pH above 6; iii. Once the pH has stabilized, said salt of an alkaline earth metal insoluble at basic or neutral pH is added to the mixture, at room temperature and with medium stirring; - In order to prepare the second mixture, the successive steps of: i. Heating a volume of water to 70°; ii. Adding said soluble salt of an alkaline earth metal to said volume of water; iii. After complete dissolution of said soluble salt of an alkaline earth metal in water, the mixture is left to cool with moderate stirring at room temperature. iv. Adding said acidifying compound to said mixture; v. Letting said mixture stand until the pH is stabilized between 2 and 4, preferably between 3.2 and 3.6, and until a homogeneous mixture is obtained; vi. Once the pH is stabilized and the mixture is homogeneous, the solution is then ready to be packaged in a spray bottle.