EP3781120A1

EP3781120A1 - Film-forming system with barrier effect, in particular against air pollution, of natural origin and for use in cosmetics

Info

Publication number: EP3781120A1
Application number: EP19724547.5A
Authority: EP
Inventors: Léon Mentink; Daniel Wils; Sophie PIOT
Original assignee: Roquette Freres SA
Current assignee: Roquette Freres SA
Priority date: 2018-04-17
Filing date: 2019-04-17
Publication date: 2021-02-24
Also published as: US20210038483A1; JP2021522169A; JP7454506B2; CN112188884A; BR112020021196A2; WO2019202264A1; FR3080042A1; CA3097464A1; FR3080042B1; KR20200144110A

Abstract

The subject matter of the application is a film-forming system, preferably for cosmetic use, made up of at least one pregelatinised starch and of at least one non-starch polysaccharide selected from: gums of plant origin, preferably gums originating from algae or plants, gums of microbial origin,and cellulose derivatives. The film-forming system according to the invention provides a barrier effect, in particular against air pollution. The application also relates to a method for manufacturing such a film-forming system and to the cosmetic compositions, in particular topical compositions, containing said film-forming system, such as skincare products, hair care products, make-up products, solar protection products, hygiene products or perfumes.

Description

Film-forming system with a barrier effect, especially against atmospheric pollution, of natural origin and use in cosmetics

The present application relates to the use in topical application of a film-forming system of natural origin, used in particular as an anti-air pollution agent, having the effect of creating a film on the surface of the skin or hair acting as a barrier to polluting particles.

The application also relates to a cosmetic composition having a barrier and anti-pollution effect comprising the film-forming system in a physiologically acceptable medium.

The present application provides a solution to two current needs in cosmetics: provide a product as natural as possible, and protect the skin from environmental aggressions, including air pollution.

Cosmetic products are formulated products made from blends, combinations or shaping of multiple ingredients. Today we are looking for questions of public health, respect for the environment and sustainability, more and more to formulate them from natural ingredients instead of synthetics. Natural polymers, in the form of gums and resins, long used as binders soluble in water, film-forming agents but also thickeners, thus find some youth.

Environmental pollution, and more particularly the atmospheric pollution known as "smog", is composed of particles and inorganic fibers that may comprise heavy metals, covered, and bound together, by toxic or carcinogenic organic compounds such as polycyclic aromatic hydrocarbon compounds, furans, aldehydes, can even be associated with pathogenic microorganisms. Such particles have sizes ranging from less than 1 μm up to 500 μm. The smaller these particles are, the more their toxicity is increased. According to a study conducted by L'Oréal, particles ranging in size from 2.5 μm to 10 μm are the most harmful: they penetrate deeply into the epidermis where they cause serious chemical degradation.

Air pollution causes premature aging of the skin. The aging process caused by this pollution has been shown to be directly related to epidermal lipid peroxidation, oxidative stress, apoptosis and UVB-induced cellular damage, resulting in the appearance of blackheads. , a decrease in the brightness of the skin, and an increase in the sensitivity of the skin. Protecting the skin against environmental pollution is therefore a new cosmetic target to protect the appearance and health of the skin, while maintaining a sensory texture on the skin, skin and skin. nails or hair.

Initially, the industry used polymers of natural origin for this film-forming function with an anti-pollution barrier effect. However, the latter had a number of disadvantages, especially in terms of color, odor, purity, consistency of efficiency and viscosity stability. These reasons have led to their substitution by synthetic or semi-synthetic polymers.

Carbomeres that are widely used in cosmetics are well known. The Carbopol ^® range developed by LUBRIZOL is an example. There may be mentioned in particular Carbopol ^® Ultrez 10NF which is a copolymer of polyethylene glycol and long chain alkyl acid ester, created to provide film-forming properties to a wide variety of cosmetic formulations.

Nevertheless, the cosmetics industry today faces new challenges in terms of environmental protection, preservation of our fossil resources, carbon footprint and safety and consumer protection. From this point of view, it reconsiders its formulations and returns as much as possible towards the use of solutions of natural origin for the formulation of its products. Science and technology are advancing in this field in order to propose technical solutions, reliable, efficient, allowing the formulator to achieve effective film-forming functions in the products he produces, with natural ingredients, highly respectful of the environment and the consumer.

In this respect, the Applicant has succeeded in developing a new film-forming system with a barrier effect, especially for atmospheric pollution, from a mixture of at least one pregelatinized starch and at least one selected non-starch polysaccharide. among gums of plant origin, gums of microbial origin, and cellulosic derivatives. From this combination, the Applicant has managed to develop a film forming system, particularly well suited to cosmetic formulations.

The film-forming system according to the invention is capable of being applied to the human epidermis or any other external part of the human body, such as in particular the hair, in the form of an aqueous composition, which, after drying, leads to the formation of a film on the surface of the epidermis. This film is a protective barrier, forming a double skin, which prevents or reduces contact of the epidermis or hair system with air pollution particles. When the epidermis or the hair system, thus covered by the film, is exposed to microparticles, rinsing with water eliminates part of the microparticles deposited on the film, whereas in the absence of film, no washing out with water is possible. The film-forming system of the invention provides a film having protective properties of the skin and the hair system vis-à-vis polluting atmospheric particles, in particular microparticles: reduction of exposure to these particles, and reduction of adhesion of these particles on the epidermis or the hair system. In addition, compared with films formed with a film-forming agent of petrochemical origin such as polyacrylates, the reduction in adhesion is greater with the film-forming system according to the invention.

The film-forming system according to the invention also makes it possible to confer a film-forming function on aqueous cosmetic compositions, in particular aqueous solutions, and to stabilize them, in a totally unexpected and synergistic manner between its various constituents. In this respect, the viscosity obtained in the presence of the mixture is much greater than that observed for each of the constituents taken separately, or for the combinations of only two of these constituents.

The film-forming system according to the invention advantageously has a modulable viscosity and cleverly chosen to allow its use in a sufficient concentration in the cosmetic composition without leading to an overly thickened texture of the latter and to obtain after application the best film-forming effect and a film as continuous as possible on the skin or the hair.

In addition, the film-forming system according to the invention makes it possible to obtain a very high stability of the viscosity over time, without significant changes in texture, over periods of several months. Such a result is particularly advantageous, and makes it possible to achieve the high level of stability required for cosmetic products in which said film-forming system is made to be used.

From the sensory point of view, the film-forming system according to the invention also leads to particularly advantageous properties by making it possible to obtain cosmetic products. smooth texture, which after application give a particularly soft and pleasant touch.

As a result, the film-forming system according to the invention makes it possible to obtain both a barrier and a protective film against pollution, but also to stabilize gels or emulsions such as skincare or make-up creams, to adjust their textures and to improve their sensory properties by advantageously giving them a non-greasy, non-spilling and particularly soft and fresh touch.

Also, a first object of the present invention consists of a film-forming system, preferably for cosmetic use, consisting of:

a) at least one pregelatinized starch,

b) at least one non-starch polysaccharide chosen from:

i. gums of plant origin, preferentially gums derived from algae or plants,

ii. gums of microbial origin,

iii. cellulosic derivatives.

According to a first embodiment, the film-forming system of the present invention can take the form of a system consisting of:

At least one pregelatinized starch,

And at least one non-starch polysaccharide chosen from gums of plant origin and gums of microbial origin.

According to a second embodiment, the film forming system of the present invention may take the form of a system consisting of:

At least one pregelatinized starch,

At least one non-starch polysaccharide chosen from gums of plant origin and gums of microbial origin,

And at least one non-starch polysaccharide chosen from cellulose derivatives.

A second subject of the present invention relates to a process for preparing a film-forming system, through the steps of: a) providing an aqueous solution,

b) heating the aqueous solution at a temperature between 20 ° C and 80 ° C, preferably between 20 ° C and 50 ° C, and more preferably between 20 ° C and 30 ° C, c) stirring into the aqueous solution at least one pregelatinized starch, and at least one non-starch polysaccharide chosen from gums of plant origin, gums of microbial origin, or cellulose derivatives, in order to obtain a medium,

A third subject of the present invention relates to a cosmetic composition comprising the film-forming system according to the invention.

A fourth and final subject of the present invention relates to the cosmetic use of a film-forming system according to the invention. More particularly, the present invention relates to the use of the film-forming system according to the invention in a topical composition, preferably for use on the human epidermis, to provide said topical composition with a barrier property, preferably anti-air pollution.

The film-forming system according to the present invention is a mixture that is at least binary, comprising at least 50%, or better still 60%, by weight relative to the total weight, at least one pregelatinized starch. Such starches may comprise amylose and amylopectin in varying proportions. Especially preferred are pregelatinized starches derived from corn, potato, wheat, rice, pea, oats, lentils, faba beans, beans, beans, chickpeas, or combinations of those -this. Preferably, this starch is a waxy starch, that is to say rich in amylopectin and low in amylose, preferably containing at least 95% m of amylopectin. This may include waxy corn starch, potato starch or rice starch.

The pregelatinized starches are generally prepared by thermal, chemical or mechanical techniques capable of causing simple swelling, partial bursting, or even complete solubilization of the starch granules so that they become partially or totally soluble in the starch granules. water according to a process known as cold, that is to say by dispersion in water at a water temperature below 45 ° C, better below 35 ° C, and more preferably close to room temperature.

Thus, preferably, the pregelatinized starch has more or almost no more granules having a Maltese cross in polarized light. The preferred techniques for obtaining a pregelatinized starch are techniques for cooking / drying starch suspensions in an aqueous medium such as atomization, drum cooking or extrusion. Autoclaving or indirect heat exchanger heating are also possible cooking methods and tend to produce complex colloidal dispersions consisting of intact, fragmented and swollen granules. Examples of a process for the preparation of such starches can be found in the documents US 3,086,890, US 3,607,394 or FR 2,822,471.

This pregelatinized starch may or may not be modified before or after pregelatinization, that is to say after application of the baking / drying treatment described above.

When it is desired to retain an unmodified pregelatinized startee that is to say non-grafted by chemical or enzymatic means, this pregelatinized starch will advantageously be chosen from waxy starches, that is to say rich in amylopectin and poor in weight. amyloidosis. This may include waxy corn starch, potato or rice, the viscosity of which could be adjusted by simple hydrolysis according to techniques well known to those skilled in the art.

When it is desired to have a starch having very highly film-forming properties while being very stable in the formulation of cosmetic products, or may then then preferably choose a modified pregelatinized starch. In terms of modification, it may then be one or more modification (s) by the physical route, physical-chemical route, chemical route or enzymatic route. It may especially be a treatment, or several treatments combined with each other, dextrinification, acid hydrolysis, oxidizing or enzymatic route, carboxymethylation, hydoxypropylation, hydroxyethalion, acetylation, octenylsuccinylation, cationization, crosslinking, grafting. Preferably, the pregelatinized starch is chosen from modified starches, in particular dextrinified, hydrolyzed, carboxymethylated, hydroxypropylated, acetylated, octenylsuccinated or cationic, pregelatinized. More preferentially, the pregelatinized starch is chosen from carboxymethylated, hydroxypropylated, acetylated, and octenylsuccinated starches, pregelatinized.

It should be noted, however, that thermal or mechanical techniques capable of causing simple swelling, partial bursting, or even complete solubilization of the starch granules so that they become soluble in water according to a method known to cold, are not necessary when certain physicochemical or chemical modifications applied to starch are sufficiently advanced. Indeed, it is possible to use as pregelatinized starch within the meaning of the invention, only dextrinified, hydrolysed, cationized, hydroxypropylated or caboxymethylated products. presenting more or almost more granules with a Maltese cross in polarized light simply because of their modification.

In particular, it is preferred to choose from pregelatinized starches, nonionic pregelatinized starches and in particular those of the range marketed by the Applicant under the trade PREGEFLO ^®, GLUCIDEX ^®, ^® or STABILYS TACKIDEX ^®. Examples of such most preferred starches are acetylated or hydroxypropylated starches, such as acetylated starch PREGEFLO ^® CH 40.

The film-forming system according to the invention consists of a second component which is a non-starch polysaccharide. This component may be chosen from: gums of plant origin, preferably gums derived from algae or plants; gums of microbial origin; or cellulosic derivatives. By non-starch polysaccharide, the applicant understands the polysaccharides of cellulosic origin or of microbial origin, such as the exopolysaccharides, which are predominantly, or even completely, constituted of saccharides linked together by osidic bonds in beta conformation, and which may exhibit linear or branched structure.

As gum of plant origin, there may be mentioned in particular:

gums derived from seeds or exudates of plants such as gum arabic, konjac gum, guar gum, locust bean gum, gum tragacanth, tara gum, cassia gum, karaya gum, gum psyllium, pectin and pectates or their derivatives and mixtures;

gums extracted from algae such as agar-agar, galactomannans, alginates or carrageenans or their derivatives and mixtures;

As a gum of microbial origin, mention may in particular be made of gums derived from a microbial fermentation such as xanthans, gellans, mannan, scleroglucans or their derivatives and mixtures, and preferably a xanthan gum.

Preferably, this gum of plant or microbial origin used in the film-forming system according to the invention is a nonionic polysaccharide. Gums derived from fermentation such as xanthans, gellanes, mannans and scleroglucans, and in particular xanthanes and scleroglucans, and more particularly xanthans, are preferred. Such xanthan gums generally have a molecular weight included between 1,000,000 and 50,000,000 Da. Among the products available commercially include for example the product Xanthan Gum FNCS-PC Jungbunzlauer International AG, the product Keltrol ^® CG-T company CP Kelco, the product Cosphaderm ^® X 17 of the Cosphatec society Kahlgum 6673 FEE - Xanthan Gum from KahIWax, Rhodicare ^® S and Rhodicare ^® XC from Solvay and VANZAN ^® NF-C from Vanderbilt Minerais.

As cellulose derivative, it is possible to retain the modified celluloses, in particular methylcelluloses, hydroxyalkylcelluloses, ethylhydroxyethylcelluloses, methylethylcelluloses, carboxymethylcelluloses, hydroxypropylcelluloses, hydroxypropylmethylcelluloses; carboxymethylcelluloses and hydroxyethylcelluloses being preferred, with hydroxyethylcelluloses being the most preferred. In particular, the following commercial products may be mentioned: Natrosol ™ 250 HHR PC from Ashland Specialty Chemical; Especial CFI of Chemir; Tylose ^® Fl 15 YG4 SE Tylose ™ and Cellosize HEC QP 40 DowDuPont (Dow).

Although the relative proportions between the various constituents of the binary mixture are not fundamental, it is preferable for the film-forming system to be the most efficient that the pregelatinized starch is predominant with respect to the entire film-forming system, ie, represents more than 50% by weight and preferably more than 60% by weight, or even more than 70% by weight, of the entire film-forming system.

Thus, according to a first embodiment, the film-forming system according to the invention comprises, and preferably consists of:

1 to 12 parts by dry weight of at least one pregelatinized starch,

0.01 to 5 parts, preferably 0.01 to 2 parts, by dry weight of at least one non-starch polysaccharide chosen from gums of plant origin, gums of microbial origin and cellulose derivatives.

According to a second embodiment, the film-forming system according to the invention comprises, and preferably consists of:

a) 1 to 12 parts by dry weight of at least one pregelatinized starch,

b) 0.01 to 2 parts of at least one gum of vegetable or microbial origin.

More preferably, it comprises, or better consists of:

a) from 5 to 11 parts by dry weight of at least one pregelatinized starch,

b) 0.1 to 1 part of at least one gum of vegetable or microbial origin. Most preferably, it comprises, or better consists of:

a) from 6 to 10 parts by dry weight of at least one pregelatinized starch,

(b) 0.2 to 0.8 parts of at least one gum of plant or microbial origin.

And, according to a third embodiment, the film-forming system according to the invention comprises, and preferably consists of:

a) 1 to 12 parts by dry weight of at least one pregelatinized starch,

(b) 0.01 to 2 parts of at least one gum of vegetable or microbial origin,

c) and 0.01 to 3 parts of at least one cellulose derivative.

More preferably, it comprises, or better consists of:

a) from 5 to 11 parts by dry weight of at least one pregelatinized starch,

(b) 0.1 to 1 part of at least one gum of plant or microbial origin,

c) 0.1 to 2 parts of at least one cellulosic derivative.

Most preferably, it comprises, or better consists of:

a) from 6 to 10 parts by dry weight of at least one pregelatinized starch,

b) 0.2 to 0.8 parts of at least one gum of vegetable or microbial origin, c) 1 to 1.5 parts of at least one cellulose derivative.

According to an advantageous variant, the film-forming system according to the invention has in water a Brookfield viscosity measured at 20 ° C. of between 1,000 and 20,000 mPa.s, preferably between 1,500 and 15,000 mPa.s. and most preferably between 2,000 and 10,000 mPa.s, for a concentration ranging from 1 to 10%, preferably from 2 to 6%. Typically this viscosity will be between 1,000 and 15,000 mPa.s, better between 2,000 and 10,000 mPa.s for a concentration of 4% in water. Brookefield viscosity is measured with a Brookfield DV-II + Pro viscometer, at a speed of 20 rpm with a spindle adapted to the measured viscosity: the spindle chosen is spindle SP3 when the viscosity is less than or equal to 5000 mPa.s, SP4 when the viscosity is between 5000 mPa.s and 7000 mPa.s and SP5 when the viscosity is greater than or equal to 7000 mPa.s.

The film-forming system according to the invention makes it possible to reduce the exposure of the epidermis and hair to polluting atmospheric particles, by preventing or reducing the adhesion of the microparticles. Indeed, when it is applied to the skin by means of an aqueous cosmetic composition, the film forming system leads after evaporation of water, to the formation of a film on the surface of the epidermis. This film acts as a physical barrier between the body part and the surrounding atmosphere, so that some of the particles atmospheres to which it is exposed, in particular those of micron size, called microparticles, in particular of size between lpm and 10 pm, can not pass through it, and thus can not come into contact with the underlying parts, such as in particular the epidermis. This reduces the number of pollution particles likely to be deposited in particular on the viral epidermis, to penetrate and cause degradation: the film-forming system according to the invention therefore limits the adverse effects of air pollution on the skin. the epidermis or any other part of the body.

A second advantage of the film forming system according to the invention is to facilitate the removal of microparticles deposited for example on the epidermis, by washing, in particular by rinsing with water. After application and drying on the epidermis, the barrier film obtained also has the particularity of not retaining the particles. Rinsing the film with water is enough to remove some of the particles deposited on the film. Compared with petrochemical film-forming agents, the film-forming system according to the invention has an increased efficiency in reducing the adhesion of the particles to the skin.

Another object of the present invention is a method for producing a film-forming and stable system, through the steps of:

a) providing an aqueous solution,

b) heating the aqueous solution at a temperature between 20 ° C and 80 ° C, preferably between 20 ° C and 50 ° C, and more preferably still at a temperature close to room temperature,

c) stirring into the aqueous solution at least one pregelatinized starch, and at least one non-starch polysaccharide selected from gums of plant origin, gums of microbial origin, or cellulose derivatives, so as to obtain a medium

Those skilled in the art will be able to adapt the stirring speed of the medium, in particular according to the quantity of the ingredients to be dispersed. But a stirring speed of between 1000 and 5000 rpm appears quite acceptable.

It is of course also that the method according to the invention takes over all the characteristics listed above relating to the binary system manufactured according to said method.

The film-forming system according to the invention is very stable and non-allergenic for the skin. It also offers the advantage of having to give consistency of viscosity and texture, not not dependent on pH or the presence of electrolytes. In other words, this system is little affected by the pH of the medium, or by the presence of mono, di or trivalent salts. This criterion is all the more important as, in general, products for cosmetic use and in particular for topical application are liable to be subjected to or exposed to variations in pH. Thus, the pH of the skin, slightly acidic, varies for example between 4 and 6. Having a product that does not present any particular limit of use in terms of pH or the presence of salts represents a very great technical advantage. for a cosmetic composition.

Finally, a last object according to the invention consists of a cosmetic composition containing the film forming system, and in particular stable, according to the invention.

Indeed, the film forming system, and in particular stable, according to the invention allows the easy realization of emulsions both very stable and very thin, with textures that are flexible and have a fresh feel, silky and non-greasy, even for high levels in the dispersed fatty phase. Preferably, the cosmetic composition comprises the film-forming system in a concentration of between 1 and 10% by weight, more preferably between 1.5 and 8% by weight and better still between 2 and 6% by weight.

Said cosmetic composition may especially be a skin care product, such as a moisturizing, anti-wrinkle, anti-aging, slimming, firming, body balm or beauty mask and may be in the form of thickened solutions, gels, milks, creams, suspensions, aerosols or mousses.

Said cosmetic composition may in particular be a makeup product for the eyes, such as a mascara, a liner, or a facial makeup product such as a powder, a foundation, a face, or a make-up product for nails or varnish , or a lip makeup product such as a lipstick or a lip gloss.

Said cosmetic composition may in particular be a solar product such as a protection or a self-tanner.

Said cosmetic composition may especially be a personal hygiene product such as a soap, a depilatory, a deodorant.

Said cosmetic composition may in particular be a hair product such as a shampoo, a color, a tincture, a perm, a fall arrest lotion, a lacquer, a fixative.

Said cosmetic composition may in particular be a perfume, a toilet water, a perfume water. The following examples will make it easier to understand the present invention without limiting its scope.

Examples

In the set of examples, different formulations have been made, with the following products:

Pregeflo ^® CH 40 marketed by Roquette Frères

Pregeflo ^® CR 3510 sold by the company Roquette Frères: it is a waxy maize starch and pregelatinized hydroxypropylated a hydroxypropyl content of about 7% w,

Company Xanthan gum marketed by CP Kelco under the name Keltrol ^® CG-T Hydroxyéthylecellulose (HEC) sold by Ashland Specialty Chemical under the name Natrosol 250 HHR ™ PC

All viscosities are determined from a Brookfield DV-II + Pro viscometer, at a speed of 20 rpm with a spindle adapted to the measured viscosity: the spindle chosen is spindle SP3 when the viscosity is less than or equal to 5000 mPa.s, SP4 when the viscosity is between 5000 mPa.s and 7000 mPa.s and SP5 when the viscosity is greater than or equal to 7000 mPa.s.

Example 1 Preparation of O / W Emulsions

This example illustrates the preparation of oil-in-water type emulsions containing, as film-forming agent, either a film-forming agent of petrochemical origin (Table 1), or a film-forming agent according to the invention (Tables 2 and 2bis).

Table 1: emulsion A, reference, with film-forming agent of petrochemical origin

Table 2: INV1 emulsion with film-forming system according to the invention

Table 2bis: INV2 emulsion with film-forming system according to the invention

The procedure for preparing an emulsion is as follows: the aqueous phase is prepared by dispersing the film-forming agent in water at 35-40 ° C. with stirring with a light deflocculator at 1000 rpm for at least 10 minutes. . The emulsifier is then added with stirring at 35-40 ° C. Apart from this, the oily phase is heated to 35-40 ° C. The oily phase is then emulsified in the aqueous phase at 35-40 ° C. with stirring with a deflocculating powder at 1500 rpm for 15 minutes. Finally, we add the preservative. The emulsion is kept under stirring until it is at room temperature.

The emulsions prepared according to this procedure and the compositions given in Tables 1, 2 and 2bis form creams that can be applied to the skin. After having been applied, they form a protective film, whose atmospheric particle barrier properties are evaluated in the following example.

Table 3: Characteristics of Prepared Emulsions

Example 2: Anti-pollution barrier effect

This example compares the performance of the microparticle antipollution barrier effects for the three emulsions prepared in Example 1.

To do this, tests were carried out on human epidermis of 10 volunteers aged 18 to 65 years, using as experimental model coal particles of sizes between 1 pm and 5 pm, called microparticles. These microparticles of coal properly model the actual polluting microparticles, such as engine exhaust gas particles.

Preparation of the microparticles of coal:

Prior to the tests, a sufficient quantity of coal microparticles was prepared by subjecting coal to the action of a household mill for 10 minutes. This grinding provides micron sized particles having a distributed size distribution predominantly between 1 μm and 5 μm.

Test procedure on the epidermis of volunteers:

On the forearm of each volunteer, three areas of 1 cm by 1 cm were delineated. For each zone thus delimited, the following two measurements are carried out: a measurement of counting of the number of black microparticles thanks to a photograph taken with a Dino-Lite digital microscope then processed by image analysis, as well as a measurement of the colorimetry with a Minolta Chromameter © CR-200.

Counting microparticles:

High resolution photographs taken with the Dino Lite Digital Microscope are processed with the GNU Image Manipulation Software (GIMP). We first made a projection along an axis (black and white) to highlight the black microparticles, and standardize the images. The number of black pixels was then counted with the GIMP software. Measurement of colorimetry:

The Minolta Chromameter CR-200 is an objective measuring tool for the color of surfaces. It provides a result consisting of three L *, a *, and b * coordinates in the 1976 CIE color space (also known as the CIELAB color space). Only the parameter L *, which characterizes the clarity of the color, has been used: L * = 0 corresponds to the color black, L * = 100 indicates a white color.

Conducting the test on volunteers:

Measurements of microparticle counting and colorimetry are carried out before the application of the emulsions, that is to say on the virgin skins (T0 measurements).

Three zones were covered with the emulsions to be tested, one with emulsion A, one with emulsion INV1, one with emulsion INV2. For this, about 2 mg of emulsion per cm ² of skin was applied by depositing the required amount with a pipette and then spreading with a spatula. The volunteers then waited 20 minutes to allow the emulsion to dry. The third zone is kept blank to constitute the control zone. Measurements were taken (T1 measurements).

The particles of charcoal were applied to the 3 zones by dabbing them with a makeup sponge impregnated with particles, then the measurements were taken (T2 measurements).

The 3 zones were then rinsed by flowing 100 mL of water over the entire area of each zone, and measurements were taken (T3 measurements).

The results presented in the following table were obtained:

Table 4: average results of the number of black pixels obtained on the panel of volunteers

Table 4a: Mean L * Result Results on the Volunteer Panel The pollution barrier effect was then evaluated by calculating the percentage change in the number of black pixels and the clarity between T3 and T2, relative to the values at T2.

Table 5: average percentages of variation between T3 and T2 relative to T2

Table 5bis: average percentages of variation between T3 and T2 relative to T2

In the control zone, the absence of a barrier effect was verified: the rinsing with water does not eliminate the microparticles deposited (variation less than 1% insignificant). Rinsing increased the clarity by 24.81%, which is significant, probably due to the removal of undetected microparticles from the count measurement due to size below the limit of detection of the digital microscope.

In the zone covered with emulsion A, containing the petrochemical film-forming agent, the barrier effect is clearly demonstrated, as expected: the number of black pixels has decreased by 5.97%, which is quite significant, and the Clarity increased 59.95%, 35% more than the control area. In the zone covered with the INV1 emulsion, containing the film-forming system according to the invention, the barrier effect has also been observed, surprisingly and unexpectedly, and is even improved with respect to the zone covered with the emulsion A: the reduction in the number of black pixels reaches 8.64%, 2.7% more than the emulsion A; clarity reaches 64.17%, 4% more than emulsion A.

The reduction in the number of black pixels, and simultaneously, the increase in clarity, on the skin area covered with a film formed by application of the INV1 emulsion containing a film-forming system according to the invention, demonstrate that the film-forming system according to the invention effectively prevents the adhesion of microparticles on the skin, and also facilitate their removal by washing, especially by rinsing with water.

The INV2 emulsion containing a film-forming system according to the invention comprising, as pregelatinized starch, a pregelatinized and hydroxypropylated waxy corn starch exhibits improved barrier effect results compared to the INV1 emulsion. There is indeed a reduction in the number of black pixels of 22.7%, and an increase in clarity of 82.6%.

Example 3: sensory parameters

This example illustrates the evolution of various sensory parameters observed for aqueous solutions containing various film-forming systems according to the invention, after 48 hours.

All formulations were made as follows:

1) Weigh and mix the different components of the film forming system,

2) Heat the water up to 40 ° C,

3) Under the stirring turbine at 2000 rpm, disperse the mixture of ingredients added little by little,

4) Leave stirring until the emulsion is at room temperature.

The whiteness descriptor is defined by the color scheme in Figure 1. The product is examined under the lamp and compared to the color palette by a panel of evaluators.

The rope is an important descriptor for the pick-up stage of the product. It is evaluated by placing between 50 and 100 μL of the product on the thumb, which is then pinched between the thumb and forefinger slowly, then slowly taking off the index finger of the thumb: it is then observed whether a connection wire between the thumb and the index is formed (spinning product) or not (non-spinning product). In the case where a connection wire is formed, the distance between the thumb is evaluated. and the index which leads to the breaking of the thread, and then we note the running character on a scale of 0 to 10: 0 corresponds to the total absence of connection wire, 10 corresponds to a connection wire which persists under a maximum distance between thumb and forefinger.

The spreading is evaluated by examining the product after having deposited on the back of the hand 50 to 100mI of the product, during its spreading in 10 rotations, under a lamp. Sprawl is particularly important that there is little resistance to movement between the ^5th and the ^10th round of the hand.

Sticky is a descriptor of the "afterfeel" stage. It is evaluated by examining the product under a lamp after placing on the back of the hand 50 to 100 μL of the product, then spreading it in 10 rotations. A finger is repeatedly pressed and released on the surface of the hand where the product has been applied. During this movement, the adhesion force between the finger and the skin of the hand is evaluated, and it is noted on a scale of 0 to 10: 0 corresponds to the total absence of adhesion, 10 corresponds to an adhesion such as the finger can not be removed from the skin of the hand.

Finally, the penetrating character of the product is evaluated by an examination under the lamp of the product two minutes after making 10 rotations of the product on the back of the hand, by sliding on the skin. A panel of evaluators then assesses the amount of product residue recovered.

Table 6 demonstrates that all the formulations tested make it possible to obtain a satisfactory sensory parameterization. In particular, we always get a low-spin product with a descriptor less than or equal to 3; spreading well, with a spreading descriptor greater than or equal to 5 and most often greater than or equal to 7, little sticky, with a corresponding descriptor less than or equal to 4 and penetrating; with a corresponding sensory descriptor greater than or equal to 6. With the exception of certain formulations rich in hydroxyethylcellulose, very white formulations with whiteness descriptors greater than or equal to 6 are obtained overall.

The invention thus makes it possible to obtain satisfactory products from a sensory point of view.

Table 6: Sensory results of aqueous solutions containing film-forming systems according to the invention

Claims

1 - film forming system consisting of:

At least one pregelatinized starch,

And at least one non-starch polysaccharide chosen from cellulose derivatives.

2 - film forming system according to claim 1, characterized in that the pregelatinized starch is derived from corn, potatoes, wheat, rice, peas, oats, lentils, faba beans, beans, beans, chickpeas, or combinations thereof, and preferably derived from a waxy starch and in particular a starch waxy corn, potato or rice.

3 - Film-forming system according to any one of the preceding claims, characterized in that the pregelatinized starch is a modified starch, preferably acetylated, hydroxyethylated, hydroxypropylated, cationized, anionized, or crosslinked.

4 - Film-forming system according to the preceding claim, characterized in that the pregelatinized starch is an acetylated starch.

5 - Film-forming system according to any one of the preceding claims, characterized in that the gums of plant origin are gums from seeds or exudates of plants, or gums extracted from algae, or derivatives of said gums. vegetable origin.

6 - Film-forming system according to any one of the preceding claims, characterized in that the gums of microbial origin are the gums from a microbial fermentation or derivatives of said gums of microbial origin.

7 - Film-forming system according to the preceding claim, characterized in that the gums of microbial origin are xanthan gums. 8 - Film-forming system according to any one of the preceding claims, characterized in that the cellulosic derivatives are modified celluloses including methylcelluloses, hydroxyalkylcelluloses, ethylhydroxyethylcelluloses, methylethylcelluloses, carboxymethylcelluloses, hydroxypropylcelluloses, hydroxypropylmethylcelluloses, carboxymethylcelluloses and hydroxyethylcelluloses being preferred.

9 - film forming system according to the preceding claim, characterized in that the cellulose derivatives are hydroxypropylmethylcelluloses.

10 - Film-forming system according to any one of the preceding claims, characterized in that it comprises, and preferably consists of:

1 to 12 parts by dry weight of at least one pregelatinized starch,

And 0.01 to 5 parts, preferably 0.01 to 2 parts, by dry weight of at least one non-starch polysaccharide chosen from gums of plant origin, gums of microbial origin and cellulose derivatives.

11 - film-forming system according to claim 10 characterized in that it comprises, and preferably consists of:

1 to 12 parts, preferably 5 to 11 parts, by dry weight of at least one pregelatinized starch,

And 0.01 to 2 parts, preferably 0.1 to 1 part, by dry weight of at least one gum of vegetable or microbial origin.

12 - Film-forming system according to one of claims 10 or 11, characterized in that it comprises, and preferably consists of:

0.01 to 2 parts, preferably 0.1 to 1 part, by dry weight of at least one gum of plant or microbial origin,

And 0.01 to 3 parts, preferably 0.1 to 2 parts, by dry weight of at least one cellulose derivative.

13 - Film-forming system according to claim 12, characterized in that it comprises, and preferably consists of: 6 to 10 parts by dry weight of at least one pregelatinized starch,

0.2 to 0.8 parts by dry weight of at least one gum of vegetable or microbial origin,

And 1 to 1.5 parts by dry weight of at least one cellulose derivative.

14 - film forming system according to any one of the preceding claims, characterized in that it is of cosmetic use, preferably topically.

15 - Process for manufacturing a film-forming system, through the steps of:

a) providing an aqueous solution,

c) Introduce with agitation in the aqueous solution at least one pregelatinized starch, at least one plant gum of plant or microbial origin, and at least one cellulose derivative, so as to obtain a medium.

16 - Cosmetic composition comprising a film-forming system according to any one of claims 1 to 14, preferably in a concentration of between 1 and 10% by weight, more preferably between 1.5 and 8% by weight, and better still between 2 and 6% by weight.

17 - Composition according to claim 16, characterized in that it is a skin care product, a makeup product for the eyes, a solar product, a personal care product, a hair product or perfume.

18 - Cosmetic use of the film-forming system according to any one of Claims 1 to 14.

19 - cosmetic use according to claim 18 characterized in that the film forming system is used in a topical composition, preferably for use on the human epidermis, to provide a barrier property, preferably air pollution, to said topical composition.