FR3143294A1 - Process for preparing an article, in particular a cosmetic article loaded with hydrophilic active ingredient in a dry form - Google Patents

Abstract

Process for preparing an article, in particular a cosmetic article loaded with hydrophilic active ingredient in a dry form. The present invention relates to a process for preparing a cosmetic article adaptable to the shape of the face, neck and/or décolleté comprising a non-woven support sheet. woven, made of non-synthetic fibers on which is immobilized, in the dry state and in a non-covalent manner, at least one hydrophilic active ingredient intended to exert a specific action on the skin, characterized in that it comprises at least the formation, on one face of a non-woven, porous support sheet made of non-synthetic fibers, a deposition at least partially in depth, of a powdery and dry mixture of at least said hydrophilic active ingredient with at least said hydrophilic binding agent and exposing said deposit to a calendering operation. Figure for abstract: None

Description

Process for preparing an article, in particular a cosmetic article loaded with hydrophilic active ingredient in a dry form

The present invention relates to cosmetic treatment devices, in particular applicators for cosmetic products. By “cosmetic product”, we mean any composition as defined in EC Regulation No. 1223/2009 of the European Parliament and of the Council dated November 30, 2009, relating to cosmetic products.

It concerns in particular devices capable of conforming to the shape of the area to be treated and advantageously capable of adapting to the reliefs of the face, neck and/or neckline, for example a facial mask.

It also concerns more particularly the implementation of such devices for the topical administration of one or more hydrophilic active ingredients, in particular water-soluble, but packaged in the dry state in these devices.

Hydrophilic active ingredients may in fact have a lack of stability when they are packaged, in a solubilized or dispersed form in an aqueous medium, over a prolonged time and may therefore be subject to partial degradation during prolonged storage in this form. To prevent this undesirable phenomenon, it is usual to combine these active solutes with one or more preservatives. However, there is a desire to free ourselves as much as possible from the use of such preservatives in cosmetic products.

The inventors were therefore concerned with the development of a new type of packaging conducive to the conservation of these hydrophilic active ingredients in a dry form but also compatible with aqueous solubilization or dispersion of the latter at the time of their contact with the skin area to be treated.

This formulation in the dry state at the level of a device, which is also flexible to adapt to the reliefs of the face, neck and/or décolleté like, for example, a mask for the face, also imposes to satisfy a number of additional requirements.

It is necessary to guarantee lasting immobilization of the powder formulation of these active ingredients on the application surface of this device.

This same device must be suitable for packaging a wide variety of powder formulations, whether in terms of particle size or nature of active ingredients, inert or living.

Any agglomeration phenomenon, such as caking for example, of this powder formulation at the device level, as well as any risk of degradation of these active ingredients must be prevented.

These active ingredients must be transferred effectively upon contact with the skin area to be treated and in a solubilized form.

To all of these requirements are added those of offering consumers an attractive device in aesthetic terms, which is also respectful of the environment and whose development involves a simple process and imposes the smallest possible carbon footprint. .

As appears from what follows, the inventors have precisely developed such a device, also known as a cosmetic article, and a corresponding manufacturing process making it possible to provide satisfaction in these terms.

Thus, according to one of its aspects, the present invention relates to a method for preparing an article, in particular cosmetic, adaptable to the shape of the face, neck and/or neckline comprising a non-woven support sheet (10) , made of non-synthetic fibers and at which is immobilized, in the dry state and in a non-covalent manner, at least one hydrophilic active ingredient (11) intended to exert a specific action on the skin, characterized in that it comprises at least the steps consisting of:

- Dispose of said active ingredient (11) in a dry powder form,

- Have at least one hydrophilic binding agent (12), in particular water-soluble, with a melting point varying from 55°C to 140°C, in particular from 60°C to 110°C, in a dry powder form,

- Form on one face of a non-woven, porous support sheet (10) made of non-synthetic fibers, a deposit, at least partially in depth, of a powdery and dry mixture of at least said hydrophilic active ingredient with at least said hydrophilic binding agent,

- Expose said deposit to a calendering operation carried out at a temperature and pressure conducive to the fusion of said binder but inactive with regard to said active ingredient and the fibers of said support sheet and preferably at a temperature varying from 100 ° C to 140 °C and a pressure varying from 0.4 kN to 600 kN and in particular for less than 30 seconds, and

- Recover said support sheet loaded with hydrophilic active ingredient.

In particular, the calendering operation is carried out with a compression force varying from 40 kN/m² to 10,000 kN/m² and preferably from 100 kN/m² to 2,000 kN/m².

As can be seen from the above, the hydrophilic active ingredient and said binding agent are brought into contact with the face of the support sheet (10) to be impregnated, in the form of a dry powdery mixture.

According to a particular embodiment, this mixture can be produced directly on the area of the face of the support to be impregnated with hydrophilic active ingredient.

According to a preferred embodiment, this mixture is carried out before the formation of the deposit on the face of the support to be impregnated with hydrophilic active ingredient. More precisely, this mixture can be carried out in a horizontal or vertical powder homogenizer or grinder type mixer, in batches or continuously by introducing all the ingredients to be mixed or even ground.

Thus, the present invention relates more particularly to a variant of the process for preparing an article, in particular cosmetic, adaptable to the shape of the face, neck and/or neckline comprising a non-woven support sheet (10), made of non-woven fibers. synthetic at which is immobilized, in the dry state and in a non-covalent manner, at least one hydrophilic active ingredient (11) intended to exert a specific action on the skin, characterized in that it comprises at least the steps consisting of has :

- Have a dry and powdery mixture of at least one hydrophilic active ingredient (11), in particular water-soluble, with at least one hydrophilic binding agent (12), in particular water-soluble, with a melting point varying from 55 °C to 140°C,

- Form on one side of a non-woven, porous support sheet (10) made of non-synthetic fibers, a deposit, at least partially in depth, of said mixture,

- Expose said deposit to a calendering operation carried out at a temperature and pressure conducive to the fusion of said binder but inactive with regard to said active ingredient and the fibers of said support sheet and preferably at a temperature varying from 100 ° C to 140 °C and a pressure varying from 0.4 kN to 600 kN for less than 30 seconds, and

- Recover said support sheet loaded with hydrophilic active ingredient.

In the process of the invention and its variant embodiment, the formation of the deposit of the mixture of said hydrophilic active ingredient and said hydrophilic binding agent comprises an impregnation operation, mechanical or not, dedicated to making it penetrate at least partly into the porosity of said support sheet. This operation is carried out before the calendering operation.

More precisely, this impregnation operation is chosen from a brushing operation, a scraping operation applied to the surface of said deposit, a vibration operation imposed on said support sheet, a suction operation applied at the level of the face of the sheet support opposite to that supporting said mixture, or even a combination of at least two of these operations.

Thus, the deposit of the mixture, dedicated to being exposed to the subsequent calendering operation, is distributed at least in part or preferably for the most part in the porosity of the non-woven support sheet (10).

For the purposes of the invention, the expression essentially means at least 60% by weight, or even at least 90% by weight, relative to the total weight of the mixture.

The method according to the invention has the advantage of being compatible with the use of powder mixtures of very diverse particle sizes and in particular having a particle size varying from 1 µm to 2000 µm, and preferably varying from 5 µm to 1700 µm.

This particle size can be characterized with, for example, an Aero dry process disperser such as the Mastersizer 3000 laser diffraction particle size analyzer (Malvern Panalytical).

Furthermore, calendering, carried out according to the invention, has the advantage of not altering in any way the active ingredient and the fibers of the support sheet.

As detailed below, the calendering considered according to the invention is a calendering of very short duration, and in particular of duration less than 30 seconds. It can also be described according to the invention as “flash calendering”.

In particular, the temperature considered for calendering is adjusted to a value higher than the melting point of the binder used, but also to a value lower than the yellowing temperature of the fibers forming the porous and non-woven support sheet and significantly lower to that of the melting point of the asset to be immobilized, simultaneously considered. Thus, the aesthetic appearance of the non-woven support sheet is preserved at the end of this process and the specific action expected of the active ingredient on the skin as well as its hydrophilicity are at the same time not affected by this calendering operation. .

Furthermore, when the support sheet loaded with dry active ingredient is brought into contact with water, advantageously no phenomenon of lumps appearing is observed. The active ingredient is delivered in its entirety to the surface of the skin to which the active ingredient-loaded support sheet is applied.

According to a particular embodiment, the hydrophilic binder is water-soluble and has a melting point varying from 60°C to 110°C.

According to a particular embodiment, the binder is a water-soluble plant exudate, and in particular comprises or even consists of an exudate of Aloe Vera leaves.

According to another particular embodiment, the hydrophilic active ingredient is a vitamin and in particular vitamin C.

In particular, said hydrophilic active ingredient and said hydrophilic binding agent are used in an active/binder weight ratio varying from 95/5 to 50/50, in particular from 90/10 to 70/30.

As specified above, the support sheet (10) is non-woven and is made of non-synthetic fibers.

More particularly, said fibrous support contains at least regenerated cellulose fibers, and where appropriate wood pulp fibers and/or paper pulp fibers.

The present invention also relates to an article, in particular cosmetic, adaptable to the shape of the face, neck and/or décolleté comprising a non-woven support sheet, made of non-synthetic fibers and which contains less of a hydrophilic active ingredient intended to exert a specific action on the skin characterized in that said active ingredient is immobilized at said support sheet, in the dry state, in a non-covalent manner and in association with less than one hydrophilic plant exudate and with a melting point varying from 55°C to 140°C.

The present invention also relates to an article, in particular cosmetic, adaptable to the shape of the face, neck and/or neckline comprising a non-woven support sheet comprising, in the dry state, at least one hydrophilic active ingredient intended to exert an action specific to the skin, characterized in that said support comprises at least regenerated cellulose fibers and further comprises at least one hydrophilic binding agent with a melting point varying from 55°C to 140°C.

The present invention further aims at the use of a particularly cosmetic article according to the invention to treat the skin of the face, neck and/or décolleté.

According to a first variant, the fibrous support of said article is moistened, in particular by soaking, imbibition, or spraying in water before application, then applied to the skin, preferably previously wet, by being stretched there or not, so as to to adapt to the morphology of the user.

According to a second variant, the fibrous support of said article is applied in the dry state to wet skin.

According to a third variant, the fibrous support of said article is applied in the dry state to dry or wet skin, then is moistened there, for example by sprinkling with water.

schematically and partially represents an example of an installation for implementing the preparation process according to the invention.

detailed description

As described above, the process aims to develop an article adaptable to the shape of the face, neck and/or neckline which is capable of containing, in the dry state, at least one hydrophilic and in particular water-soluble active ingredient and to ensure its release from said article upon contact with water.

The development of the method according to the invention is based in particular on the observation by the inventors that the calendering technique and in particular as considered according to the invention, allows access in a simple and reproducible manner to such an article subject to moreover a specific choice of support and to combine with this hydrophilic active ingredient a binding agent which is also hydrophilic and has a particularly adjusted melting point.

Advantageously, the method according to the invention does not require the use of an alternating electric field or even ultrasound to immobilize said active ingredient on said support.

Likewise, the process according to the invention does not require the use of a thermoplastic binding agent or even a crosslinking agent or a thermosetting resin to immobilize said active ingredient on said support.

Fibrous support

As specified above, the constituent fibers of the support considered according to the invention for immobilizing at least one hydrophilic active ingredient, and in particular water-soluble, are non-synthetic fibers.

For the purposes of the invention, non-synthetic fibers are fibers not derived from materials exclusively accessible by chemical synthesis, such as for example a synthetic polymer.

Thus, the non-synthetic fibers retained according to the invention are advantageously chosen from natural fibers of material of natural origin such as for example natural cellulose fibers, fibers generated from at least one material of natural origin such as for example natural cellulose, recycled cellulosic fibers such as for example circulose, biosourced fibers such as for example fibers obtained by bio-fermentation such as for example microbial cellulose and mycelium foam and their mixtures.

These fibers are advantageously hydrophilic, absorbent and furthermore not subject to a yellowing phenomenon when exposed to a temperature strictly below 150°C, preferably strictly below 130°C. They are also non-hot melt.

In particular, the non-synthetic fibers are chosen from natural cellulose fibers, regenerated cellulose fibers, wood pulp fibers, paper fibers, fibers from seeds such as cotton and kapok, fibers from plant stems such as flax, hemp, jute and nettle, fibers from leaves such as abaca, fibers from fruits such as coconut and their mixtures.

For the purposes of the invention, “a regenerated cellulose fiber” is a fiber obtained from natural cellulose transformed by a succession of chemical operations, in particular as specified below for the Lyocell product.

The natural cellulose used to manufacture regenerated cellulose fibers can thus come from different wood pulps (beech, white pine, eucalyptus, etc.), or even bamboo pulp.

According to a particular embodiment, the fibers constituting the fibrous support comprise at least and in particular consist of regenerated cellulose fibers, in particular like those of the Lyocell product.

More specifically, this product is obtained from wood pulp which is mixed with an environmentally friendly organic dissolving agent and water. The assembly is then heated under vacuum to remove water until the cellulose dissolves and a spinning solution is formed. This is then filtered and pressed through spinnerets then placed in a spinning bath where the fibers are formed. Such a product is notably marketed under the names Tencel® and Veocel®.

According to another particular embodiment, the fibrous support considered contains at least wood pulp fibers.

According to another particular embodiment, the fibrous support contains regenerated cellulose fibers and one or more other fibers chosen from wood pulp fibers, paper fibers, fibers from seeds such as cotton and kapok, fibers from plant stems such as flax, hemp, jute and nettle, fibers from leaves such as abaca, fibers from fruits such as coconut and their mixtures.

According to a particular embodiment, the fibrous support contains regenerated cellulose fibers and wood pulp fibers and/or paper pulp fibers and in particular regenerated cellulose fibers and wood pulp fibers.

As a representative of fibrous supports consisting of such mixtures of fibers, we can in particular cite the non-woven supports Tricell® from the company Ecowipes, the CAC supports from the company Mondi, the Sontara® supports from the company Glatfelter and the BioLace supports ® from the Suominen company.

According to a particular embodiment, the synthetic fibers constituting said fibrous support consist of regenerated cellulose fibers and wood pulp fibers.

According to another particular embodiment, the fibrous support contains regenerated cellulose fibers and recycled non-synthetic textile fibers.

As specified above, the fibrous support is in the form of a sheet or in other words a thin plate of fibrous material.

The constituent fibers of said support are not woven and therefore their structural organization provides porosity at the level of the support sheet considered according to the invention.

The porosity of the fibrous support can be characterized by optical microscopy. The porosity of the nonwoven can also be characterized by its air permeability.

In particular, the fibrous and porous support not loaded with active ingredients according to the invention may have a surface mass varying from 35 g.cm ^-2 to 80 g.cm ^-2 , preferably from 40 g.cm ^-2 to 50 g. cm ^-2 .

This porosity is precisely conducive to loading the non-woven fibrous support with a significant quantity of hydrophilic active ingredient. This porosity is also conducive to bringing the immobilized active ingredient into contact with water at the level of the non-woven fibrous support considered according to the invention.

According to a particular embodiment, the fibrous support recovered according to the process of the invention is loaded with at least 10 g/m², or even with at least 25 g/m² of hydrophilic active ingredient.

Hydrophilic active

For the purposes of the invention, the term “hydrophilic active ingredient” means a water-soluble or water-dispersible active ingredient capable of forming hydrogen bonds.

In particular, the cosmetic active ingredient is a water-soluble active ingredient.

It can be represented by a single active ingredient or a mixture of hydrophilic active ingredients. For the purposes of the invention, the term “hydrophilic active ingredient” covers these two alternatives.

Immobilized at the fibrous support, the hydrophilic active ingredient remains endowed with its properties, in particular its cosmetic activity and its hydrophilicity. In other words, its native properties are not affected by the calendering operation carried out in particular at a temperature varying from 100°C to 140°C and a pressure varying from 0.4 kN to 600 kN for its immobilization.

It is present at the level of the support it impregnates, in a dry and powdery state. It may in particular be a native powder but also a powder obtained by conventional drying or by atomization, or freeze-drying for example.

For the purposes of the invention, the term dry means that the ingredient concerned, in particular the active ingredient as well as the hydrophilic binder detailed below, contains less than 6% by weight, preferably less than 5% by weight of water, and more preferably less than 2% by weight of water, relative to its total weight.

A dry ingredient thus has excellent powder fluidity, conducive to its intimate mixing with other ingredients and its penetration into the porosity of the support sheet considered.

The active ingredient, immobilized according to the invention, is not covalently linked to the fibrous support and is therefore capable of being released from it by interacting with an aqueous medium.

This active ingredient may in particular be an anti-oxidant, healing, hydrating, depigmenting, and/or anti-aging agent.

As representative and illustrative of these categories of active ingredients, we can cite in particular the following compounds:

C-glycoside compounds

In particular, this cosmetic active ingredient can be chosen from C-glycoside compounds, of the following general formula:

in which :

- R denotes an unsubstituted linear alkyl radical in C ₁ -C ₄ , in particular in C ₁ -C ₂ , in particular methyl;

- S represents a monosaccharide chosen from D-glucose, D-xylose, N-acetyl-D-glucosamine or L-fucose, and in particular D-xylose;

- X represents a group chosen from -CO-, -CH(OH)-, -CH(NH ₂ )-, and preferably a –CH(OH)- group;

as well as their cosmetically acceptable salts, their solvates such as hydrates and their optical isomers.

By way of illustration and not limitation of the C-glycosides more particularly suitable for the invention, the following compounds may in particular be cited:

- C-beta-D-xylopyranoside-n-propane-2-one;

- C-alpha-D-xylopyranoside-n-propane-2-one;

- C-beta-D-xylopyranoside-2-hydroxy-propane;

- C-alpha-D-xylopyranoside-2-hydroxy-propane;

- 1-(C-beta-D-glucopyranosyl)-2-hydroxy-propane;

- 1-(C-alpha-D-glucopyranosyl)-2-hydroxy-propane;

- 1-(C-beta-D-glucopyranosyl)-2-amino-propane;

- 1-(C-alpha-D-glucopyranosyl)-2-amino-propane;

- 3'-(acetamido-C-beta-D-glucopyranosyl)-propane-2'-one;

- 3'-(acetamido-C-alpha-D-glucopyranosyl)-propane-2'-one;

- 1-(acetamido-C-beta-D-glucopyranosyl)-2-hydroxyl-propane;

- 1-(acetamido-C-beta-D-glucopyranosyl)-2-amino-propane;

as well as their cosmetically acceptable salts, their solvates such as hydrates and their optical isomers.

Niacinamide compound

In particular, this cosmetic active ingredient can be chosen from niacinamide (also known as Vitamin B3), N,N-diethylniacinamide, N-picolylniacinamide, N-allylniacinamide.

Adenosine and its analogues

In particular, the cosmetic active ingredient can be chosen from adenosine and its analogues such as 2'-deoxyadenosine, 2',3'-isopropoylidene adenosine, toyocamycin, 1-methyladenosine; N-6-methyladenosine, adenosine N-oxide, 6-methylmercaptopurine riboside, 6-chloropurine riboside, 5'-adenosine monophosphate, 5'-adenosine diphosphate and 5'-adenosine triphosphate, phenylisopropyl- adenosine (PIA), 1-methylisoguanosine, N-6-Cyclohexyladenosine (CHA), N-6-cyclopentyladenosine (CPA), 2-chloro-N-6-cyclopentyladenosine, 2-chloroadenosine, N-6 -phenyladenosine, 2-phenylaminoadenosine, N-6-phenethyladenosine, 2-p-(2-carboxy-ethyl) phenethyl-amino-5'-Nethylcarboxamido-adenosine (CGS-21680), N-10-ethylcarboxamido- adenosine (NECA), 5'(N-cyclopropyl)-carboxamidoadenosine, metrifudil, erythro-9-(2-hydroxy3-nonyl) adenine (EHNA) and iodotubercidin.

Adenosine is notably available commercially in powder form from the company Pharma Waldhof.

Ascorbic acid and derivatives

In particular, the cosmetic active ingredient can be chosen from ascorbic acid, also called Vitamin C, in D or L form, advantageously in L form, and its analogues chosen from its salts, preferably sodium ascorbate, magnesium or sodium ascorbylphosphate, glycosylated ascorbic acid, its ose esters and its phosphorylated metal salts.

The ose esters of ascorbic acid which can be used in the invention are in particular the glycosylated, mannosylated, fructosylated, fucosylated, galactosylated Nacetylglucosamine, N-acetylmuramic derivatives of ascorbic acid and their mixtures, and more especially ascorbyl-2 glucoside or 2-O-α-D glucopyranosyl of L-ascorbic acid or even 6-O-β-D-galactopyranosyl of L-ascorbic acid. These latter compounds as well as their preparation processes are in particular described in documents EP 487 404 and EP 425 066.

The metal salt of phosphorylated ascorbic acid can be chosen from alkali metal ascorbyl phosphates, alkaline earth metal ascorbyl phosphates and transition metal ascorbyl phosphates.

The ascorbic acid derivatives can be chosen from 5,6-di-O-dimethylsilylascorbate sold under the reference PRO-AA by the Exsymol Company, the potassium salt of dl-alpha-tocopheryl-dl-ascorbyl-phosphate sold under the reference Sepivital EPC by the Senju Pharmaceutical Company, magnesium ascorbyl phosphate, sodium ascorbyl phosphate marketed under the reference Stay-C 50 by the Roche Company and ascorbyl glucoside marketed by the Hayashibara company.

This may in particular be the product marketed by the company BASF under the name Ascorbic Acid/80 Mesh.

According to a particular mode, the support according to the invention is loaded with at least one vitamin and in particular vitamin C or one of its derivatives, in particular its salts.

Hyaluronic acid

In particular, this cosmetic active ingredient can be chosen from hyaluronic acid or one of its derivatives.

In the context of the present invention, the term “hyaluronic acid or one of its derivatives” covers in particular the basic unit of hyaluronic acid of formula:

The term “hyaluronic acid or one of its derivatives” also includes in the context of the present invention the linear polymer comprising the polymer unit described above, in a sequence by the alternating glycosidic bonds β(1,4) and β(1,3), having a molecular weight (MW) which can vary between 380 and 13000000 daltons. This molecular weight depends largely on the source of obtaining the hyaluronic acid and/or the preparation methods.

The term “hyaluronic acid or one of its derivatives” also covers according to the invention the salts of hyaluronic acid and in particular the alkaline salts such as sodium salt and potassium salt.

In its natural state, hyaluronic acid is present in peri-cellular gels, in the basic substance of the connective tissues of vertebrate organs such as the dermis and epithelial tissues and in particular in the epidermis, in the synovial fluid articular, in the vitreous humor, in the human umbilical cord and in the cristagalli process.

Thus, the term “hyaluronic acid or one of its derivatives” includes all the fractions or subunits of hyaluronic acid having a molecular weight notably included in the molecular weight range recalled above.

In the context of the present invention, it is preferred to use hyaluronic acid fractions which do not exhibit inflammatory activity.

As an illustration of the different hyaluronic acid fractions, reference can be made to the document “Hyaluronan fragments: an information-rich system”, R. Stern et al . , European Journal of CeIl Biology 58 (2006) 699-715, which reviews the listed biological activities of hyaluronic acid based on its molecular weight.

Finally, the term "hyaluronic acid or one of its derivatives" also includes esters of hyaluronic acid, in particular those in which all or part of the carboxylic groups of the acid functions are esterified with alcohols or oxyethylenated alkyls, comprising 1 with 20 carbon atoms, in particular with a substitution rate at the level of D-glucuronic acid of hyaluronic acid varying from 0.5% to 50%.

Mention may in particular be made of the methyl, ethyl, n-propyl, n-pentyl, benzyl and dodecyl esters of hyaluronic acid. Such esters have notably been described in D. Campoccia et al. “Semisynthetic resorbable materials from hyaluronan esterification”, Biomaterials 19 (1998) 2101-2127.

Hyaluronic acid may in particular be available from the company Hyactive under the trade name CPN (PM: 10 to 150 kDa), from the company Soliance under the trade name Cristalhyal (PM: 1.1 x 10 ⁶ ), from the company Bioland under the name Nutra HA (PM: 820000 Da), the company Bioland under the name Nutra AF (PM: 69000 Da), the company Bioland under the name Oligo HA (PM: 6100 Da) or the company Vam Farmacos Metica under the name D Factor (PM: 380 Da).

Preferably, sodium hyaluronate is used.

Salicylic acid compounds

In particular, this cosmetic active ingredient can be chosen from salicylic acid compounds.

The salicylic acid compound is preferably chosen from salicylic acid and the compounds of the following formula:

in which :

- the radical R designates an aliphatic chain having 2 to 22 carbon atoms, saturated, linear, branched or cyclic; an unsaturated chain having 2 to 22 carbon atoms containing one or more conjugable double bonds; an aromatic ring linked to the carbonyl radical directly or via saturated or unsaturated aliphatic chains having 2 to 7 carbon atoms; said groups being able to be substituted by one or more substituents, identical or different, chosen from (a) halogen atoms, (b) the trifluoromethyl group, (c) hydroxyl groups in free form or esterified with an acid having 1 with 6 carbon atoms or (d) a carboxyl function in free form or esterified with a lower alcohol having from 1 to 6 carbon atoms;

- R’ is a hydroxyl group;

as well as their salts from a mineral or organic base.

Among the particularly preferred salicylic acid compounds, mention may be made of n-octanoyl-5-salicylic acid (or capryloyl salicylic acid), n-decanoyl-5-salicylic acid, n-dodecanoyl-5-acid. salicylic acid, n-heptanoyl-5-salicylic acid, and their corresponding salts.

The salicylic acid compound is preferably chosen from salicylic acid and n-octanoyl-5-salicylic acid, and more preferably is n-octanoyl-5-salicylic acid.

The salts of the compounds of formula illustrated above can be obtained by salification with a mineral or organic base. As an example of a mineral base, we can cite alkali or alkaline earth metal hydroxides such as sodium hydroxide, potassium hydroxide or ammonia.

Among the organic bases, we can cite amines and alkanolamines. Quaternary salts like those described in patent FR 2 607 498 are particularly interesting.

This active ingredient can also be a plant extract such as madecassoside, extracted from Centella asiatica.

More precisely, this asset can be chosen from:

- vitamins and their derivatives, in particular their esters, such as in particular niacinamide (3-pyridinecarboxamide) nicotinamide (vitamin B3), provitamin B5 also known as panthenol, tocopherol (vitamin E) and its esters (such as acetate tocopherol), ascorbic acid and its derivatives (vitamin C),

- moisturizers, such as in particular urea, hydroxyureas, glycerol, polyglycerols, glycerolglucoside, diglycerolglucoside, polyglycerylglucosides, xylitylgiucoside and plant extracts, in particular tea, mint, orchid, soy, aloe vera, honey, and in particular glycerol,

- C-glycoside compounds, and preferably hydroxypropyl tetrahydropyrantriol (or proxylane)

- antioxidant compounds,

- anti-aging active ingredients, such as for example hyaluronic acid compounds, and in particular sodium hyaluronate, salicylic acid compounds and in particular n-octanoyl-5-salycilic acid (capryloyl salicylic acid), adenosine, c-beta-d-xylopyranoside-2-hydroxypropane and the sodium salt of 3-hydroxy-2-pentylcyclopentyl)acetic acid,

- keratolytic agents such as lactic acid or glycolic acid, and

- their mixtures.

Preferably, an article according to the invention comprises at least one water-soluble cosmetic active ingredient chosen from moisturizers, C-glycoside compounds, and preferably hydroxypropyl tetrahydropyrantriol, hyaluronic acid compounds, and in particular sodium hyaluronate. , salicylic acid compounds, and in particular n-octanoyl-5-salycilic acid (capryloyl salicylic acid), ascorbic acid and its derivatives, lactic acid, adenosine and its analogues, plant extracts such as madecassoside, niacinamide compounds, and mixtures thereof.

Even more preferably, an article according to the invention comprises at least one anti-aging cosmetic active ingredient, in particular chosen from hydroxypropyl tetrahydropyrantriol, or proxylane, adenosine, niacinamide compounds, salicylic acid compounds, ascorbic acid, and mixtures thereof, more particularly chosen from hydroxypropyl tetrahydropyrantriol, adenosine, niacinamide compounds, ascorbic acid, and mixtures thereof.

According to a particular embodiment, the fibrous support obtained according to the invention contains at least vitamin C and in particular from 15 g/m² to 35 g/m² of vitamin C.

According to a particular embodiment, said cosmetic active ingredient constitutes from 50% to 95% by weight, and in particular from 70% to 90% by weight, of the total weight of dry matter immobilized at said support.

Hydrophilic binding agent

As specified above, the hydrophilic active ingredient according to the invention is immobilized on the substrate in association with at least one hydrophilic binder with a melting point varying from 55°C to 140°C, in particular from 60°C to 110°C. .

The binder also comes in a dry form.

In particular, it is water-soluble.

The binder has a melting temperature of less than 150°C, preferably less than 130°C, in order to be effectively melted during the calendering process, that is to say in less than 15 seconds.

Furthermore, as the binder is exposed to a calendering step, it must not be subject to a phenomenon of yellowing at a temperature strictly below 100°C, preferably strictly below 130°C.

In addition to its ability to contribute to the immobilization of the active ingredient at the level of the fibrous support, the binder can also have a cosmetic activity with respect to the skin, and possibly provide a cosmetic effect, in synergy or not, with the effect attached to the active ingredient impregnated in the fibrous support.

According to a particular embodiment, the binder is a plant exudate.

According to a particular embodiment, the water-soluble binder comprises and in particular consists of an exudate of Aloe Vera leaves.

As a representative of such an exudate, reference may be made to the commercial product Aloe Vera Freeze Dried Powder ^® 200:1 from Mexi Aloe Lab.

According to a particular embodiment, the loaded fibrous support according to the invention contains vitamin C, and at least one exudate of Aloe Vera leaves, and in particular from 15 g/m² to 35 g/m² of vitamin C.

According to another particular embodiment, the loaded fibrous support according to the invention comprises at least regenerated cellulose fibers and contains vitamin C, in particular from 15 g/m² to 35 g/m² of vitamin C.

According to another particular embodiment, the loaded fibrous support according to the invention comprises at least regenerated cellulose fibers and contains at least vitamin C and an exudate of Aloe Vera leaves and in particular from 15 g/m² to 35 g/m² of vitamin C.

In addition to at least one hydrophilic active ingredient and at least one hydrophilic binder in accordance with the invention, the fibrous support recovered at the end of the process may contain one or more additional compounds.

Additional compounds

As additional compounds we can cite anti-caking agents, powder flow aids, stabilizers, regulators and pH buffers.

These additional compounds are also present in the dry state and in particular in powder form.

In a particular embodiment, the fibrous support recovered according to the invention also contains at least one anti-caking agent which can in particular be chosen from silica, sodium carbonate, talc, bamboo exudate (rich in silica) and their mixtures, and in particular at least silica.

In particular, the powder mixture considered to form the deposit may contain from 0.2% to 3% by weight, and preferably from 0.5% to 1.5% by weight of anti-caking agent(s), relative to to the total weight of active dry matter (active + binder).

In a particular embodiment, the charged fibrous support according to the invention also contains at least one stabilizer which may in particular be sodium citrate.

In particular, the powder mixture considered to form the deposit may contain from 0.2% to 2% by weight, and preferably from 0.5% to 1.5% by weight of stabilizer(s), relative to the total weight. of active dry matter (active + binder).

In a particular embodiment, the fibrous support loaded according to the invention also contains at least one thickener or texturizer.

Of course, those skilled in the art will take care to choose this or these possible additional compounds in such a way that their properties are not, or substantially not, altered by the impregnation process according to the invention to which they are subjected.

According to an advantageous embodiment, the fibrous support obtained according to the invention is preferably free of compounds likely to be harmful to humans and/or the environment, that is to say it comprises less than 0.01% by weight, or even is free of compounds likely to be harmful to humans and/or the environment.

Thus, it is in particular free of silicone compound and/or ethylenediaminetetraacetic acid (EDTA), and preferably is free of silicone compound and ethylenediaminetetraacetic acid.

Preparation process according to the invention

The process according to the invention requires bringing a dry powder form of the hydrophilic active ingredient, to be immobilized, into contact with the non-woven and porous fibrous support to be impregnated, in the presence of a hydrophilic binding agent and a melting point. specific.

This process can be implemented with an installation for processing a fibrous support, such as that illustrated schematically in , comprising:

- a reel 30 from which the non-woven fibrous support S to be treated is unwound,

- a powder mixing unit 15,

- a powder deposition unit 20 on the support S,

- a mechanical processing unit 25, to penetrate deeper into the support S the powder previously deposited by the unit 20,

- an in-line sliding belt possibly,

- a calendering unit 40 arranged between the reels 30 and 50, downstream of the unit 25, comprising for example two rollers between which the support passes, and

- a reel 50 on which the support thus treated is wound after calendering.

The installation also includes all the conventional equipment necessary for implementing the process, such as rollers and/or belts for transporting and guiding the nonwoven, heating means, means for cutting the finished support, etc.

If necessary, the reel 50 can be removed by a support cutting and packaging station, if this is carried out online.

a) Formation of the deposit

In particular, the method according to the invention does not require prior heating of the support sheet S before depositing the asset to be immobilized.

Generally speaking, the support sheet S to be treated is unwound from a reel 30 and circulated between this reel and a reel 50 on which it is wound after treatment according to the invention.

According to one embodiment, this bringing together of the active ingredient and the binder can be carried out directly on the surface of the area of the support S to be loaded with active ingredient.

According to another embodiment, this bringing together is carried out prior to the surface deposition operation of the area of the support S to be loaded with active material. This embodiment is advantageous for forming an intimate mixture between the two ingredients considered or even adjusting a particle size range to the mixture thus formed and which is in line with the porosity of the support S to be loaded with active ingredient.

The powders of each of the ingredients can be previously ground individually, or even simultaneously, in a powder mixing unit 10, for example a mechanical grinder or a centrifuge.

According to a particular embodiment, the powders of each of the ingredients, hydrophilic active ingredient and hydrophilic binder, or even if present, one or more other additional compounds in particular as defined above, are respectively introduced in the form of a dry powder to the inside the powder mixing unit 10 such as a batch powder mixer in order to mix them intimately.

The deposition of the mixture on one of the faces of the support sheet to be loaded, can be carried out by a powder deposition unit 20 on the support S according to a technique such as sprinkling, using a powder funnel, by spraying using for example a nozzle.

For example, this deposit may include a step of sprinkling the powder mixture to be impregnated on top of the fibrous support. The support S thus covered with the mixture can then be exposed to a mechanical operation, in particular as detailed below, dedicated to making the mixture penetrate the porosity of the support.

Sprinkling is generally carried out over the entire surface of the support S to be impregnated. In some cases, it is possible to use localized dusting or to use a stencil to impregnate only certain areas of the support.

The formation of the deposit of the mixture comprises in particular an impregnation operation, mechanical or not, dedicated to making said mixture penetrate at least in part into the porosity of said support sheet.

Thus, to obtain uniform impregnation of the deposit and at least partially in depth, it is also advantageous to implement a mechanical treatment unit 25, to penetrate deeper into the support S the powder previously deposited by the unit 20 .

Thus, it is advantageous for this deposit to be formed, jointly or not, with an impregnation operation chosen in particular from a brushing operation, a scraping operation applied to the surface of said deposit, a vibration operation imposed on said support sheet, a suction operation applied to the face of the support sheet, opposite to that supporting said mixture, or even is a combination of at least two of these operations.

For example, it may involve vibration or even shaking of the deposit on the surface of the support S to stimulate the movement inside the porosity of the fibrous support of the powder deposited on the surface of this support by the deposit unit 20.

As a representative of these impregnation techniques, those based on the use of a vibrating device such as a vibrating mat can be cited in particular.

Another impregnation technique can be based on air suction applied to the back of the face of the support loaded with powder. This suction would advantageously allow excess powder to be recovered.

The deposit is said to be “partially formed at depth”, on the grounds that the powder mixture may not be entirely distributed in the pores of the fibrous support and that part of it may remain on the surface.

Generally speaking, this deposit is formed at ambient temperature 21°C +/-5°C and at atmospheric pressure.

b) Calendering operation

This operation takes place following the deposition of the powder mixture.

As it appears from the , the calendering unit 40 can be arranged between a reel 30 from which the support S to be processed is unwound downstream of the unit 25, and a reel 50, between which the support S passes.

The parameters of the calendering operation, namely temperature, pressure and time, are in fact adjusted to lead to the fusion of the binding agent considered while preventing the manifestation of an undesirable side effect with regard to the hydrophilic active ingredient. and fibers constituting the support, also exposed to this calendering.

In other words, the calendering operation alters neither the integrity, nor the effectiveness, nor the hydrophilicity of the active ingredient and does not generate a significant yellowing phenomenon of the fibers constituting the non-woven support. . The latter remains at the end of the calendering, attractive in terms of appearance for its user.

This calendering is also called flash because it is carried out on the scale of the second and in particular in a duration of less than 50 seconds, and preferably less than 30 seconds.

According to a particular embodiment, the calendering operation is carried out at a temperature varying from 100°C to 140°C and a pressure varying from 0.4 kN to 600 kN for less than 30 seconds, preferably for less than 15 seconds .

This calendering operation is generally carried out using an in-line heating calender.

At the end of this calendering step, a fibrous support sheet impregnated with at least one water-soluble active ingredient in the dry state is obtained.

This impregnation rate can in particular be characterized according to the method detailed in the experimental part and which is based on the characterization of a weight content at the level of the fibrous support loaded according to the invention.

In this case, the fibrous support is weighed following the flash calendering step and is fixed on a Bose ^® test bench (model 3330). Weighted by attaching to its end a clamp with a mass of 4 g., it is shaken for a period of 30 seconds, at a frequency of 10 Hz and with an amplitude of 12 mm. It is then weighed a second time. The ratio between the post-shaking weighing and the pre-shaking weighing makes it possible to define the impregnation rate of the powder within the fibrous material.

Of course other technologies for measuring the impregnation rate can be considered such as that based on image analysis (use of an optical microscope or a camera or digital camera).

According to a particular embodiment, the impregnation rate of the loaded fibrous support can vary from 70% to 100%, in particular from 80% to 100%, in particular from 95% to 100%.

The article obtained according to the invention is in particular in the form of a facial mask, a wipe, a disc or cushion (“pad”) and in particular in the form of a mask for the face.

According to another embodiment, the support sheet has perforations and/or cutouts.

According to a particular embodiment, the article may contain a reservoir containing the aqueous medium dedicated to the hydration of said active ingredient.

In connection with the invention, a method of cosmetic treatment is also described and proposed, in particular for cleaning and/or caring for the skin, in particular of the face, neck and/or décolleté, comprising at least the step consisting of to apply to the skin to be treated a fibrous support sheet loaded with hydrophilic active ingredient of an article according to the invention, in the presence of an aqueous medium or even water.

According to one embodiment, the fibrous support sheet is loaded with an aqueous medium or even with water prior to its application to the skin. In particular, this loading can be carried out by immersion of the support in an aqueous medium or even water, imbibition with an aqueous medium or by spraying the support with an aqueous medium or even water.

According to another embodiment, the fibrous support sheet is applied to moistened skin.

According to yet another embodiment, the fibrous support sheet is applied to dry or moistened skin, and is then brought into contact with an aqueous medium or even water, in particular by spraying or humidification.

The fibrous support sheet is kept on the skin for a specific period of time and adjusted to the release of the active ingredient in its water-soluble or water-dispersible form.

Generally this duration can vary from 1 minute to 30 minutes, or even from 2 minutes to 20 minutes, being for example of the order of approximately 10-15 minutes.

This process can in particular be useful for rehydration, anti-wrinkle, anti-puffiness, or anti-dark circles treatment, or even to provide a plumping effect.

The examples and figures which follow are presented by way of illustration and not limitation of the field of the invention.

Materials and methods

Ascorbic acid is a commercial powder product available from BASF under the name Ascorbic Acid/80 Mesh. Its particle size expressed in micrometers is as follows: D10 = 35+/-5, D50 = 160+/-70, D90 = 350+/-155 and its melting point greater than 180°C.

Aloe Vera Exudate is a powdered commercial product available from Mexi Aloe Laboratorios (marketed by Rossow). Its particle size expressed in micrometers is as follows: D10 = 20, D50 = 55, D90 = 1700 and its melting point varies from 67°C to 108°C.

The porous, non-woven support is made of Lyocell material. This is a material available from the supplier Jacob Holm (reel width = 32 cm, thickness = 0.5 mm and surface mass = 50 gm ^-2 ). The fibrous support used for the tests is cut from this non-woven roll in the form of discs.

Powder Loss Protocol:

To quantify the impregnation of the powder within the fibrous support the following protocol is implemented:

The fibrous support is weighed following the calendering step and is fixed on a Bose ^® test bench (model 3330). The fibrous support is then weighted by attaching a clamp with a mass of 4 g to its end. The fibrous support is subsequently shaken for a period of 30 seconds, at a frequency of 10 Hz and with an amplitude of 12 mm. At the end of the sequence, the support is weighed a second time. The ratio between the post-shaking weighing and the pre-shaking weighing makes it possible to define the impregnation rate of the powder within the fibrous material. The ratio between the pre-shaking weighing minus the post-shaking weighing and the pre-shaking weighing makes it possible to define the rate of powder loss following shaking.

Example 1

Impregnation d ’ powdered ascorbic acid on a non-woven disc according to ’ invention

A first step consists of grinding by centrifugation 100 g of a mixture of ascorbic acid and Aloe Vera in a weight ratio of 85:15 respectively. This grinding is carried out using a Stuart Sr4 ^® centrifuge grinder; the mill is filled to a third of its maximum capacity then grinding takes place for 1 hour at maximum power so as to obtain a mixture for deposit with a particle size as follows D10 = 16, D50 = 45, D90 = 94 µm.

The powder mixture thus obtained is then applied manually by sprinkling onto the fibrous disk, then the powder is spread uniformly and homogeneously on the surface of the fibrous material using a brush. The operation is completed when the surface mass of ascorbic acid reaches 25 gm ^-2 .

The disc and its deposit thus formed is then placed on an aluminum plate (15 cm * 15 cm) preheated in contact with the press and covered with a sheet of glass fabric coated with ^Teflon® . The assembly is then subjected to a pressing process using a LabEcon 600 heated plate press from Fontijne Presses, at a pressure of 30 kN, a temperature of 130°C for 5 seconds.

The fibrous disk thus loaded is characterized as having a powder loss of approximately 20% and a very minor and therefore insignificant yellowing is noted.

Example 2

Impregnation ’ powdered ascorbic acid on a non-woven disc according to ’ invention

The process of Example 1 is reproduced with the exception of the centrifugation operation which is replaced by mechanical grinding of 100 g of a mixture of ascorbic acid and Aloe Vera with a weight ratio of 85:15 respectively. Mechanical grinding is carried out using a Fritsch “pulverissette 14”, stirring takes place for a few seconds at a speed of 6000 rpm so as to obtain a mixture for deposit with a particle size as follows D10 = 19 , D50 = 57, D90 = 124.

The disk thus loaded is also characterized as having a powder loss of approximately 16% and a very minor, therefore insignificant, yellowing is noted.

Claims (19)

Process for preparing an article, in particular cosmetic, adaptable to the shape of the face, neck and/or neckline comprising a non-woven support sheet (10), made of non-synthetic fibers on which is immobilized, in the dry state and in a non-covalent manner, at least one hydrophilic active ingredient (11) intended to exert a specific action on the skin, characterized in that it comprises at least the steps consisting of:
- Dispose of said active ingredient (11) in a dry powder form,
- Have at least one hydrophilic binding agent (12), in particular water-soluble, and with a melting point varying from 55°C to 140°C in a dry powder form,
- Form, on one face of a non-woven, porous support sheet (10) made of non-synthetic fibers, a deposit, at least partially in depth, of a powdery and dry mixture of at least said active ingredient hydrophilic with at least said hydrophilic binding agent,
- Expose said deposit to a calendering operation carried out at a temperature and pressure conducive to the fusion of said binder but inactive with respect to said active ingredient and said fibers of said support sheet and preferably at a temperature varying from 100 ° C to 140 °C and a pressure of 0.4 kN to 600 kN and in particular for less than 30 seconds, and
- Recover said support sheet loaded with hydrophilic active ingredient. Method according to the preceding claim, in which said mixture is carried out prior to the formation of the deposit on the face of the support sheet to be impregnated with hydrophilic active ingredient. Method according to any one of the preceding claims, in which the formation of the deposit of said mixture of said hydrophilic active ingredient and of said hydrophilic binding agent comprises an impregnation operation, mechanical or not, dedicated to making said mixture penetrate at least in part into the porosity of said support sheet. Method according to the preceding claim, in which said impregnation operation is chosen from a brushing operation, a scraping operation applied to the surface of said deposit, a vibration operation imposed on said support sheet, a suction operation applied to the level of the face of the support sheet, opposite to that supporting said mixture, or even a combination of at least two of these operations. Method according to any one of the preceding claims, in which said calendering operation is carried out with a compression force varying from 40 kN/m² to 10,000 kN/m² and preferably from 100 kN/m² to 2,000 kN/m². Method according to any one of the preceding claims, in which said non-synthetic fibers are chosen from natural fibers of material of natural origin, fibers generated from at least one material of natural origin, recycled cellulosic fibers, biosourced fibers and their mixtures. Method according to any one of the preceding claims, in which the fibers constituting the fibrous support consist of regenerated cellulose fibers. Method according to any one of claims 1 to 6, in which the constituent fibers of said fibrous support comprise regenerated cellulose fibers and one or more other fibers chosen from wood pulp fibers, papermaking fibers, fibers from seeds such as cotton and kapok, fibers from plant stems such as flax, hemp, jute and nettle, fibers from leaves such as abaca, fruit fibers such as coconut and their mixtures. Method according to any one of claims 1 to 6 and 8 in which the constituent fibers of said fibrous support comprise regenerated cellulose fibers and wood pulp fibers and/or paper pulp fibers and in particular regenerated cellulose fibers and wood pulp fibers. Process according to any one of the preceding claims, in which said fibrous and porous support not loaded with active ingredients has a surface mass varying from 35 g.cm ^-2 to 80 g.cm ^-2 , preferably 40 g.cm ^-2 at 50 g.cm ^-2 . Method according to any one of the preceding claims, in which said recovered fibrous support is loaded with at least 10 g/m², or even with at least 25 g/m² of hydrophilic active ingredient. Process according to any one of the preceding claims, in which said cosmetic active ingredient is water-soluble and chosen from moisturizers, C-glycoside compounds, and in particular hydroxypropyl tetrahydropyrantriol, hyaluronic acid compounds and in particular sodium hyaluronate , salicylic acid compounds and in particular n-octanoyl-5-salycilic acid (capryloyl salicylic acid), ascorbic acid and its derivatives, lactic acid, adenosine and its analogues, plant extracts such as including madecassoside, niacinamide compounds, and mixtures thereof. Process according to any one of the preceding claims in which said cosmetic active ingredient constitutes from 50% to 95% by weight, and in particular from 70% to 90% by weight of the total weight of dry matter immobilized at said support. A method according to any one of the preceding claims, wherein said hydrophilic binder is water-soluble and has a melting point varying from 60°C to 110°C. Method according to any one of the preceding claims, in which said water-soluble binder is a plant exudate and in particular comprises or even consists of an exudate of Aloe Vera leaves. Method according to any one of the preceding claims, in which said loaded fibrous support contains vitamin C, and at least one exudate of Aloe Vera leaves, and in particular from 15 g/m² to 35 g/m² of vitamin C . Method according to any one of the preceding claims, in which said filled fibrous support comprises regenerated cellulose fibers and contains vitamin C, in particular from 15 g/m² to 35 g/m² of vitamin C. . Method according to any one of the preceding claims, in which said recovered fibrous support additionally contains at least one anti-caking agent and in particular silica. A method according to any one of the preceding claims, wherein said article is in the form of a facial mask, a wipe, a disc or pad.