EP3890682A1

EP3890682A1 - Emulsifying composition consisting of an oil-in-water emulsifier and a cyclodextrin of selected particle size, capable of providing an oil-in-water emulsion with improved sensory effects for cosmetic use

Info

Publication number: EP3890682A1
Application number: EP19868207.2A
Authority: EP
Inventors: Léon Mentink
Original assignee: Roquette Freres SA
Current assignee: Roquette Freres SA
Priority date: 2018-12-05
Filing date: 2019-12-04
Publication date: 2021-10-13
Also published as: FR3089415A1; CN113329729A; WO2020115437A1; US20220023187A1; JP2022510657A; FR3089415B1

Abstract

The present invention relates to a sensory emulsifying composition, in particular for cosmetic use, capable of making it possible to obtain an oil-in-water-type emulsion, comprising at least one cyclodextrin in the form of solid particles, said particles having a volume-average size d(4,3), measured by laser granulometry, of between 2 and 20 μm, preferably between 3 and 12 μm, and more preferably between 4 and 8 μm; and at least one emulsifier of natural origin selected from oil-in-water emulsifiers, having an HLB greater than or equal to 8, and most preferably greater than or equal to 9.

Description

Title: Emulsifying composition consisting of an oil-in-water emulsifier and a cyclodextrin of selected particle size, capable of providing a liquid oil-in-water emulsion with improved sensory effects, for cosmetic use.

The present invention relates to an emulsifying composition of plant origin, ready to use and directly usable when cold, which finds applications in particular in the field of cosmetics. This composition comprises at least one cyclodextrin in the form of solid particles, said particles having a volume average size d (4.3) measured by laser particle size, less than or equal to 20 μm, and at least one emulsifier of natural origin. The emulsifying composition according to the invention can be used as a cosmetic composition as such, or as a premix to allow an emulsion to be produced and stabilized. This emulsifying composition in particular allows the easy production of very fine liquid oil-in-water (O / W) emulsions, with varied textures, compatible with the skin. The compositions obtained have a soft, powdery feel, even when they have a high content of fatty phase in the emulsion, and spread easily, without forming fluff.

An emulsion is a dispersion of a liquid (or a material made liquid) in fine drops in another liquid immiscible with the first. It presents a macroscopically homogeneous appearance but appears heterogeneous under the microscope. The liquid in the form of drops is called dispersed (or discontinuous) phase, while the other liquid is called dispersing (or continuous) phase. In general, an emulsion is composed of two phases (simple emulsion): a hydrophilic phase (aqueous) and a lipophilic phase (fatty). An oil-in-water emulsion is called a direct emulsion.

Emulsions are widely used in the field of cosmetics. As a cosmetic product, these emulsions must meet the needs of consumers, who demand efficiency, safety and properties pleasant sensory. In order to satisfy these requirements, the emulsion formulations have become more complex over time by always incorporating more functional or sensory ingredients of synthetic origin, generally derived from petrochemicals.

It is known that most cosmetic compositions in the form of an emulsion, typically simple emulsions, are stabilized by surfactants. For example, document EP 0 685 227 proposes a very complex system of cosmetic sunscreen compositions, comprising an aqueous continuous phase, a protective system capable of filtering UV rays, a surfactant, organic solvents (alcohols and lower polyols) and at least one polymer or more particularly a crosslinked copolymer (alkyl acrylates, vinyl acetate). Document FR 2 858 777 describes an oil-in-water emulsion containing at least one fatty substance (fatty acid esters, waxes, butters, natural oils - vegetable, animal, marine, synthetic or mineral, hydrogenated oils and their mixtures), at least one surfactant (ethoxylated polyglycerol fatty acid esters, alcohol ethoxylates), at least one co-surfactant and water.

However, the use of surfactants in products intended to be applied to humans or animals, whether in topical or oral form, can be problematic. Indeed, surfactants can damage cell membranes. Thus, efforts are made, in particular in the cosmetic field, to reduce the potentially harmful effects of surfactants.

In addition, cosmetic products must now meet a new consumer expectation: the natural origin, and even more demanding, the naturalness of the compositions. In fact, consumers are now looking for cosmetic products composed essentially of natural ingredients or of natural origin, with the minimum of chemical modifications or synthetic or petrochemical grafts.

Also, one of the aims of the present invention is to provide a composition which allows the formation of stable emulsions, even according to a "cold" process, by dispersion in an aqueous phase and subsequent addition of oil or body bold. Such a composition eliminates the need for original surfactants petroleum and non-biodegradable, in particular glycol derivatives and ethoxylated derivatives. The composition according to the present invention also makes it possible to manufacture emulsions of the Pickering type. Emulsions of this type are devoid of surfactant and are stabilized by colloidal microparticles, generally silicas, which are placed at the interfaces of the continuous phase and the dispersed phase. In the context of the present invention, these colloidal particles would be organic particles made up of inclusion complexes between at least one cyclodextrin and at least one fatty molecule. These particles are very advantageously compatible with the skin or the hair and do not damage the cell membranes.

This result is all the more remarkable since the state of the art demonstrates that the manufacture of emulsifying compositions for cosmetic use containing cyclodextrins does not make it possible to obtain emulsions easily and directly when cold: it was necessary until '' then to resort to surfactants of petroleum origin. This is in particular what EP 2 091 502 B1 relates which describes an oil-in-water (O / W) emulsion containing water, a fatty substance, a modified polysaccharide, and a cyclodextrin, the essential characteristic of this O / W emulsion being that it contains surfactants with a molecular weight of less than 5,000 g / mol and in an amount of less than 2% by weight. It was therefore neither known nor obvious to produce emulsifying systems containing cyclodextrins which make it possible to obtain very fine and very stable emulsions without using petroleum-based surfactants.

Furthermore, the main attraction of the consumer for the cosmetic product is based on its sensory properties, long before the beneficial effects are observable. The challenge facing a cosmetic product is therefore to deliver a beneficial cosmetic effect while providing, before or during application, the most pleasant sensations possible. However, the removal of functional or sensory ingredients from petrochemicals, their substitution with ingredients of natural origin, or the introduction of new natural ingredients or of natural origin, can be accompanied by a degradation of the sensory properties of the cosmetic product in a more or less marked manner, in particular their appearance, the setting of the product, their application or of their properties when applied to the skin or the integuments. Thus, the compositions meeting the criteria of naturalness may prove difficult to spread, fluff or provide, on application, a crunching sensation, or a brittle sensation, or even an insufficient slippery sensation. These insufficient or degraded sensory perceptions are detrimental to the quality or image of a cosmetic product.

A previous application filed by the applicant FR1853362 not published to date, relates to an emulsifying composition comprising a cyclodextrin and an emulsifier of natural origin of HLB greater than or equal to 8. The beta-cyclodextrin used is a beta-cyclodextrin marketed by Roquette Frères under the name “Beauté by Roquette® CD 102”, of medium size in volume equal to 95 pm. However, the sensory properties obtained by means of the composition used in this application are not entirely satisfactory.

Thus, an objective of the present invention is to provide an improved emulsifying composition, for cosmetic use, offering improved sensory properties compared to the emulsifying composition of application FR1853362, in particular concerning the powdered effect, the ease of spreading, softness of touch, crunching on application, penetration of the composition and linting.

Another objective of the present invention is to provide a composition of 100% natural origin. The natural origin of the ingredients used to formulate products of current use like cosmetic compositions is today a major stake, not only with regard to the safeguard and the protection of our environment but also for the good- to be consumers. As such, the composition according to the present invention makes it possible to replace the surfactants of synthetic and in particular petroleum origin, in particular ethoxylated, which these days seeks to replace for environmental reasons, due to their poor biodegradability, and of safety. , due to the dangerousness of ethylene oxide widely used to produce polyethoxylated surfactants, which is toxic and flammable). Another objective of the present invention is to provide a ready-to-use composition, allowing the formulator a very simple implementation, with a minimum supply of energy in particular by introduction of all the ingredients in the same tank or reactor (so-called “one pot” formulation in English). From the point of view of its implementation, the emulsifying composition which is the subject of the present invention is advantageously usable according to "a cold process", that is to say even at room temperature. By "cold process", it is meant that the emulsifying composition can be used directly by dispersion in water at a water temperature below 45 ° C, better still below 35 ° C and better still at room temperature.

Another objective of the present invention is to provide a composition for cosmetic use with a broad spectrum, that is to say versatile from the point of view of the end products envisaged: from this point of view, the composition according to The invention can be used in products as diverse as lotions, creams, gels, milks, etc. Furthermore, said composition is advantageously non-irritating and non-allergic to the skin. It also offers the advantage of not depending on the pH or the presence of electrolytes: in other words, its emulsifying capacity is not affected by the pH of the medium, nor by the presence of mono, di or trivalent. This criterion is all the more important since, in general, products for cosmetic use and in particular for topical application are liable to be subjected to or exposed to variations in pH (for example, the pH of the skin is slightly acid, and varies between 4 and 6). Having an emulsifying composition which has no particular limit of use in terms of pH therefore represents a very great technical advantage for a cosmetic composition.

All of these objectives, which constitute a complex technical problem to be solved, are finally achieved thanks to the main object of the present invention, which consists of an emulsifying composition, in particular for cosmetic use, capable of allowing obtaining a liquid oil-in-water (O / W) type emulsion, comprising:

a) at least one cyclodextrin in the form of solid particles, said particles having a volume average size d (4.3) measured by laser particle size, between 2 and 20 pm, preferably between 3 and 12 pm, and more preferably between 4 and 8 pm,

b) and at least one emulsifier of natural origin, chosen from emulsifiers of the oil-in-water (O / W) type, having a hydrophilic-lipophilic balance greater than or equal to 8, preferably greater than or equal to 9.

The calculation of the HLB takes into account the molecular weights of the hydrophilic parts and the molecular weight of the molecule considered and can be obtained according to the following equation:

[Math. 1]

Hydrophilic part molecular weight

HLB = 20 - - - - - - -

Molecular mass of the molecule

Cvclodextrin

The composition according to the invention uses at least one cyclodextrin in the form of solid particles, said particles having a volume average size d (4.3) measured by laser particle size, less than or equal to 20 μm, preferably less than or equal to 12 pm, and most preferably less than or equal to 8 pm.

In the present Application, the term "cylcodextrin" designates and includes any of the cyclodextrins known to those skilled in the art, such as native and unsubstituted cyclodextrins containing from 6 to 12 glucose units linked by bonds covalent between carbons 1 and 4, and in particular the alpha-, beta- and gamma-cyclodextrins containing respectively 6, 7 and 8 units of glucose.

This term also covers "cyclodextrin derivatives", namely molecules of which at least part of the hydroxyl groups OH has been transformed into OR groups, where R generally denotes an alkyl group. From this point of view, cyclodextrin derivatives include in particular methylated, ethylated cyclodextrins, but also those substituted with a hydroxyalkyl group such as hydroxypropylated and hydroxyethylated cyclodextrins. The preferred cyclodextrins according to the present invention are alpha-, beta- and gamma-cyclodextrins. According to a preferred embodiment, the cyclodextrin used in the composition according to the invention is a beta-cyclodextrin, preferably "native", that is to say of which the hydroxyl groups are chemically unsubstituted.

Cyclodextrin may in particular be in the form of a crystalline, pseudo-crystalline or amorphous powder.

In the context of the present invention, the cyclodextrin is present in the form of solid particles characterized by a volume average size d (4.3), also called the volume average diameter, measured by laser particle size, less than or equal to 20 pm, preferably less than or equal to 12 pm, and very preferably less than or equal to 8 pm. According to a preferred embodiment, the mean size by volume of the solid particles of cyclodextrin is between 2 μm and 20 μm, preferably between 3 μm and 12 μm, and very preferably between 4 μm and 8 μm.

The solid particles of cyclodextrins can be of any geometric shape, regular or irregular, and can be well individualized cyclodextrin crystals or agglomerates of cyclodextrin crystals linked together by crystal bridges. Preferably, the solid particles of cyclodextrins have regular geometric shapes.

The volume average size, generally noted noted d (4.3), is calculated according to ISO 9276-2: 2014 from particle size distributions by volume, measured by particle size by laser diffraction, for example using a laser granulometer from the MasterSizer® range, for example “Mastersizer 2000 ™”, “Mastersizer 3000 ™”, “Mastersizer 3000E ™”, from the company Malvern Instruments®, or a laser granulometer “Particula LA960 "from the company Horiba®. These laser diffraction measurement methods can be implemented in the wet or dry process, according to the guiding principles of ISO 13320: 2009. When the wet process is used, it is recommended to use 2-propanol as the measuring fluid. Preferably, the solid particles of cyclodextrins have a size distribution by volume, measured by particle size by laser diffraction, the characteristic diameters d (10), d (50) and d (90) are such that:

a) the diameter d (10) of between 0.8 and 5.0 pm, preferably between 1.0 and 2.5 pm, and

b) the diameter d (50) is between 5 and 15.0 µm, preferably between 7 and 10.0 µm, and

c) the diameter d (90) is between 15 and 30.0 µm, preferably between 20 and 25.0 µm.

The characteristic diameters d (10), d (50) and d (90), as defined in standard ISO 13320: 2009 under the notations x10, x50 and x90, are the particle diameters corresponding respectively to 10% , 50% and 90%, of the cumulative size distribution by volume.

According to a preferred embodiment, the solid particles of cyclodextrins have a size distribution by volume, measured by particle size by laser diffraction, whose characteristic diameters d (10), d (50) and d (90) are such than :

a) the diameter d (10) is less than or equal to 5.0 pm, preferably less than or equal to 2.5 pm,

b) And the diameter d (50) is less than or equal to 15.0 pm, preferably less than or equal to 10.0 pm,

c) And the diameter d (90) is less than or equal to 30.0 pm, preferably less than or equal to 25.0 pm.

Even more preferably, the solid particles of cyclodextrins have a size distribution by volume, measured by particle size by laser diffraction, having a coefficient of variation less than or equal to 100%, preferably less than or equal to 90%, and most preferably less than or equal to 73%. As defined in ISO 13320: 2009, the coefficient of variation of the particle size distribution is the standard deviation of the particle size distribution divided by the volume average size d (4.3), also called volume average diameter. According to this preferred embodiment, the cyclodextrin is therefore in the form of solid particles whose size distribution by volume measured by particle size distribution by laser diffraction has the following characteristics:

a) A volume average size d (4.3) of between 2 and 20 μm, preferably between 3 and 12 μm, and more preferably between 4 and 8 μm,

b) A coefficient of variation less than or equal to 100%, preferably less than or equal to 90%, and more preferably less than or equal to 73%.

Thanks to this particular selected size, the cyclodextrin particles contribute to the improvement of sensory perceptions of touch, in particular by increasing the feeling of softness. In addition, this use allows a marked reduction in the crunching sensation on application, as well as a reduction in linting, or even a disappearance of this linting depending on the nature of the skins.

Natural oil-in-water emulsifier

In the present application, the term "natural origin" oil-in-water emulsifier designates any emulsifier derived from renewable resources, in particular extracted or secreted by plants, microorganisms or algae, and capable of allowing after physical modification , chemical or enzymatic, obtaining an oil-in-water type emulsion.

The oil-in-water emulsifier of natural origin having a Hydrophilic-Lipophilic balance (HLB) greater than or equal to 8, preferably greater than or equal to 9, is preferably present in the emulsifying composition in a ratio (weight / weight) oil-in-water / cyclodextrin emulsifier between 0.01: 1 and 1: 1, preferably between 0.05: 1 and 0.5: 1, more preferably between 0.10: 1 and 0 , 35: 1 and better still between 0.15: 1 and 0.30: 1.

This O / W emulsifier of natural origin preferably has a Hydrophilic-Lipophilic balance (HLB) of between 8 and 20, preferably between 9 and 16, and better still between 1 1 and 14. It can also be a chosen one among naturally biodegradable products in a hydrated natural environment. In particular, the average HLB of the entire emulsifying system of said composition is greater than or equal to 8, preferably greater than or equal to 9. The average HLB of all of the emulsifying system of the composition is calculated by carrying out a weighted average of the HLBs of each emulsifier, by weighting the HLBs of each emulsifier present by its mass fraction relative to the total mass of the emulsifiers present.

This O / W emulsifier of natural origin is preferably chosen from the following products, provided that they meet the condition on the HLB above: alkyl polyglucosides; mixtures of at least one alkyl polyglucoside and at least one fatty alcohol; non-ethoxylated fatty esters of polyols, and in particular among non-ethoxylated fatty esters of glycerol, polyglycerols, sorbitol, sorbitan, anhydrohexitols such as in particular isosorbide, mannitol, xylitol, erythritol, maltitol , sucrose, glucose, polydextrose, hydrogenated glucose syrups, dextrins and hydrolyzed starches.

The O / W emulsifier of natural origin is preferably chosen to be naturally biodegradable in a hydrated natural environment. These may especially be non-ethoxylated fatty esters of polyols obtained from fatty acid or by trans esterification from oil or mixtures of oils. The fatty acids used comprise from 8 to 22 carbon atoms, preferably from 10 to 18 carbon atoms, and in particular from 12 to 18 carbon atoms. These acids can be linear or branched, saturated or unsaturated, have one or more lateral hydroxyl functions. The oils can be saturated or unsaturated, from liquid to solid at room temperature, and optionally have hydroxyl functions, preferably with an iodine index of between 1 and 145, and in particular from 5 to 105.

The O / W emulsifier of natural origin can be chosen in particular from polyglycerol esters, and preferably from esters resulting from the reaction of polyglycerols comprising from 2 to 12 glycerol units, preferably from 3 to 10 glycerol units with at least one partially hydrogenated or non-hydrogenated vegetable oil with an iodine index of between 1 and 15, and in particular from 5 to 10. These may in particular be oleic, stearic, palmitic, lauric esters , diisostearic and caprylic of polyglycerols and in particular of the following products: Polyglyceryl-5 Dioleate from HLB about 8 (like Dermofeel® G 5 DO from Evonik Dr. Straetmans GmbH), Polyglyceryl-2 Caprate preferably having an HLB of about 9 (like HYDRIOL ® PGC.2 from HYDRIOR), Polyglyceryl-3 Stearate preferentially exhibiting an HLB of approximately 9 (such as Dermofeel® PS from Evonik Dr. Straetmans GmbH), Polyglyceryl-2 Laurate preferentially exhibiting an HLB approximately 9 (such as Dermofeel® G2L from Evonik Dr. Straetmans GmbH), Polyglyceryl-3 Palmitate preferentially exhibiting an HLB of approximately 10 (such as Dermofeel® PP from Evonik Dr. Straetmans GmbH), Polyglyceryl-10 Diisostearate preferentially exhibiting an HLB approximately 1 1 (such as Dermofeel® G10 DI from Evonik Dr. Straetmans GmbH), Polyglyceryl-6 Caprylate preferentially having an HLB of approximately 11.5, Polyglyceryl-5 Laurate preferentially exhibiting an HLB of approximately 13 (such as Dermofeel® G5L from Evonik Dr. Straetmans GmbH), Polyglyceryl-3 Caprate preferentially exhibiting an HLB of approximately 14 (such as HYDRIOL® PGC.3 from HYDRIOR), Polyglyceryl-4 Caprate preferentially exhibiting an HLB approximately 14 (such as MASSOCARE PG4 C from Masso), Polyglyceryl- 10 Monolaurate preferentially having an HLB of approximately 14.8, Polyglyceryl-6 Caprylate preferentially exhibiting an HLB of approximately 15 (such as Dermofeel® G 6 CY from Dr. Straetmans GmbH / Evonik), Polyglyceryl-10 Laurate preferentially exhibiting an HLB d '' about 16 (like Dermofeel® G 10 L from Dr. Straetmans GmbH / Evonik).

The O / W emulsifier of natural origin is preferably chosen from alkyl polyglucosides, sometimes also called alkyl polyglycosides, and designated by the acronym APG. These emulsifiers are nonionic surfactants well known per se. Patent FR 2 948 285 makes a presentation in terms of structure, and explains how to prepare them. They can be represented by the following general formula (I): R1 -0- (R2-0) p- (S) n in which:

-S represents a reducing saccharide, which can comprise between 5 and 6 carbon atoms,

-R1 denotes a linear or branched alkyl and / or alkenyl radical, preferably comprising approximately 8 to 24 carbon atoms, or an alkylphenyl radical, preferably an alkylphenyl radical in which the linear or branched alkyl group contains approximately from 8 to 24 carbon atoms,

-R2 denotes an alkylene radical containing from 2 to 4 carbon atoms,

-n denotes a value ranging from 1 to 15,

-p denotes a value ranging from 0 to 10.

By reducing saccharide, is meant in formula (I), saccharide derivatives which do not have in their glycosidic binding structures established between an anomeric carbon and oxygen of an acetal group as defined in the reference work: "Biochemistry", Daniel Voet / Judith G. Voet, p. 250, John Wyley & Sons, 1990. The oligomeric structure (S) n can be in any form of isomerism, be it optical isomerism, geometric isomerism or position isomerism; it can also represent a mixture of isomers.

According to a particular aspect of the present invention, in the definition of the compounds of formulas (I), S represents a reducing saccharide chosen from glucose, dextrose, saccharose, fructose, idose, gulose, galactose, maltose, isomaltose, maltotriose, lactose, cellobiose, mannose, ribose, xylose, arabinose, lyxose, allose, altrose, dextran or tallose and more particularly a reducing saccharide chosen from glucose, xylose or arabinose.

A first preferred variant of alkyl polyglucosides according to the present invention are C12-C20 alkyl glucosides, that is to say the compounds of formula (I) in which:

-R1 more particularly denotes a linear or branched alkyl and / or alkenyl radical containing approximately from 12 to 20 carbon atoms,

-R2 denotes an alkylene radical containing from 2 to 4 carbon atoms,

-p takes a value ranging from 0 to 3, and preferably equal to zero,

-S denotes glucose, fructose or galactose, and more preferably glucose

A second preferred variant of alkyl polyglucosides according to the present invention are the C12-C20 alkyl glucosides of the first preferred variant in which: -R1 more particularly denotes a linear alkyl radical containing about 12 to 20 carbon atoms

-p is zero,

-S denotes glucose

Alkyl polyglucosides of formula (I) are in particular commercially available under the names: Plantacare® 810 UP (R1 is C8-C10 / INCI: caprylyl / capryl glucoside), Plantacare® 818 UP (FM is C8 -C16 / INCI: Coco-glucoside), Plantacare® 2000 UP (FM is in C8-C16 / INCI: decyl glucoside) and Plantacare® 1200 UP (FM is in C12-C16 / INCI: lauryl glucoside) sold by BASF ; Macanol® 810 (FM is C8-C10), Macanol® 1200 (FM is C12-C14), Macanol® 816 (mixture of FM is C8, C10, C12, C14, C16) sold by the company FCI Technology; Neocare MF 0718 (FM is C8-C10 / INCI: caprylyl / capryl glucoside), Neocare MF 0012 (FM is C12-C14 / INCI: lauryl glucoside), Neocare MF 0002 (FM is C8-C16 / INCI: decyl glucoside), Neocare MF 818 (FM is C8-C16 / INCI: coco glucoside) sold by the company Neochem; Tego Care CG 90 (FM is C14-C16 / INCI: cetearyl glucoside) sold by the company Evonik Healthcare.

The O / W emulsifier of natural origin is preferably a mixture consisting of at least one alkyl polyglucoside and at least one fatty alcohol. In these mixtures, the alkyl polyglucosides can be chosen from all the alkyl polyglucosides useful for the invention described above. Regarding fatty alcohols useful for mixing with alkyl polyglucosides, we will find linear or branched fatty alcohols having a total number of carbon atoms ranging from 8 to 24.

Mixtures of alkyl polyglucosides and fatty alcohols useful for the invention and commercially available are those sold by the company SEPPIC: Montanov ™ 14 (INCI: Myristyl Alcohol & Myristyl Glucoside), Montanov ™ 202 (INCI : Arachidyl Alcohol and Behenyl Alcohol and Arachidyl Glucoside), Montanov ™ 68 (INCI: Cetearyl Alcohol & Cetearyl Glucoside), Montanov ™ 82 (INCI: Cetearyl Alcohol and Coco-Glucoside), Montanov ™ S (INCI: Coco- Glucoside & Coconut Alcohol ), Montanov ™ L (INCI: C14-22 Alcohols & C12-20 Alkyl Glucoside). The preferred mixture of alkyl polyglucoside and fatty alcohol is that sold by SEPPIC under the name "Montanov ™ L", which is a mixture of C14-C22 fatty alcohols and C12-C20 alkyl polyglucosides (INCI: C14-22 Alcohols & C12-20 Alkyl Glucoside).

A preferred variant of the emulsifying composition according to the invention thus comprises as an oil-in-water emulsifier of natural origin mixture consisting of at least one alkyl polyglucoside and at least one fatty alcohol, preferably at least a C12-C20 alkyl polyglucoside and at least one linear or branched fatty alcohol having a total number of carbon atoms ranging from 8 to 24, and most preferably a mixture of C14-C22 fatty alcohol and alkyl C12-C20 glucoside.

The O / W emulsifier of natural origin can also be chosen from fatty esters of dextrins or hydrolyzed starches, in particular in the form of sodium octenylsuccinate esters. These may for example be products marketed by the Applicant under the names this CLEARGUM® and in particular the products CLEARGUM® CO 01 and CLEARGUM® CO 03.

Effects of size selection of cvclodextrin particles

Compared to an emulsifying composition comprising a medium-sized cyclodextrin in volume greater than or equal to 90 μm, such as the beta-cyclodextrin “Beauty by Roquette® CD 102” sold by Roquette Frères, the emulsifying composition according to the invention makes it possible to obtain emulsions easier to spread, having a more powdery and softer feel, a clearly lower screech, penetrating more quickly on keratin materials, and leading little or no fluffing. Optionally, the emulsifying composition according to the invention also makes it possible to obtain interesting sensory effects, such as a particular texture or a feeling of freshness, according to the proportions used.

The advantageous properties of said emulsifying composition result from the combination of the two compounds used which have good synergy, both in terms of the stability of the emulsions and of sensory properties. Although we obtain very satisfactory results regardless of the proportions in which we combine these compounds, we obtain particularly convincing results when combined in a very precise ratio.

In particular, each of the different constituents of the emulsifying composition according to the invention can be integrated into a different phase of the final emulsion, before the emulsification is carried out. Alternatively, the various compounds of the present composition according to the invention are mixed together to form a premix (or premix according to English terminology), said premix can be added to any of the phases of the emulsion in which the premix will be used. The invention advantageously allows these two embodiments with the same compounds, which allows increased room for maneuver and simplified use.

The emulsifying composition according to the invention has the particular advantage of being completely of natural origin, and of being usable according to a "cold" process (that is to say implemented at room temperature ). Said composition according to the invention is, in particular, for cosmetic use and, as such, is not sensitive to small variations in pH or of salinity of the medium, is not irritating and is not likely to cause allergies, especially skin allergies. In addition, the composition according to the invention can be used to make any type of emulsion, in particular Pickering type emulsions, and is therefore suitable for a wide variety of uses: creams, milks, serums, lotions, etc.

Water

The emulsifying composition may contain water in a form known as "constituting or bound" and / or in a form known as "free". The water of constitution or bound consists of the water molecules included in the crystal structure of the cyclodextrin and / or polyol powders, and of the water molecules adsorbed on the surface of these powders by physical balance of hydration. Free water is made up of water molecules which can circulate freely between cyclodextrin and / or polyol powders. This free water can in particular suspend the cyclodextrin and / or polyol powders. According to one embodiment, the emulsifying composition comprises a constitution or bound water content of between 1% and 25%, by weight relative to the total weight of said emulsifying composition. Preferably, the water content of the constitution or bound is between 2% and 15%, very preferably between 3% and 10%.

According to one embodiment, the emulsifying composition may comprise free water at a content less than or equal to 50% by weight relative to the total weight of said emulsifying composition. Preferably, this free water content is less than or equal to 40%, more preferably 30%, and most preferably 20%.

Polvol

According to one embodiment, the emulsifying composition also comprises at least one polyol.

The polyols targeted by this Application are all the polyols known elsewhere, and in particular maltitol, mannitol, xylitol, erythritol, sorbitol, glycerol, glycerol and sorbitol being the preferred polyols. Preferably, this polyol is crystallized or is in the form of a powder.

Thus, in particular, the invention relates to an emulsifying composition, in particular for cosmetic use and capable of making it possible to obtain an emulsion of the oil-in-water (O / W) liquid type which comprises, or preferably which consists of:

1) from 40% to 95% by weight, relative to the total weight of the composition, of at least one cyclodextrin in the form of solid particles, said particles having a mean size by volume d (4.3) measured by laser granulometry , between 2 and 20 pm, preferably between 3 and 12 pm, and more preferably between 4 and 8 pm,

2) from 5% to 40% by weight, relative to the total weight of the composition of at least one emulsifier of natural origin chosen from oil-in-water emulsifiers, having an HLB greater than or equal to 8, and more preferably an alkyl polyglucoside of HLB greater than or equal to 9,

3) and from 0% to 40% by weight, relative to the total weight of the composition of at least one polyol. Preferably, this emulsifying composition according to the present invention comprises, or preferably consists of:

1) from 45% to 85% by weight, relative to the total weight of the composition of at least one cyclodextrin in the form of solid particles, said particles having a volume average size d (4.3) measured by laser particle size, between 2 and 20 pm, preferably between 3 and 12 pm, and more preferably between 4 and 8 pm,

2) from 5% to 30% by weight, relative to the total weight of the composition of at least one emulsifier of natural origin chosen from oil-in-water emulsifiers, having an HLB greater than or equal to 8, and more preferably an alkyl polyglucoside of HLB greater than or equal to 9,

3) and from 10% to 40% by weight, relative to the total weight of the composition of at least one polyol.

In the most preferred manner, this composition according to the present invention comprises, or preferably consists of:

1) from 40% to 80% by weight, relative to the total weight of the composition of at least one cyclodextrin in the form of solid particles, said particles having a volume average size d (4.3) measured by laser granulometry, between 2 and 20 pm, preferably between 3 and 12 pm, and more preferably between 4 and 8 pm,

2) from 10% to 20% by weight, relative to the total weight of the composition of at least one emulsifier of natural origin chosen from oil-in-water emulsifiers, having an HLB greater than or equal to 8, and more preferably an alkyl polyglucoside of HLB greater than or equal to 9,

3) and from 10% to 30% by weight, relative to the total weight of the composition of at least one polyol.

In the three preferred embodiments of the above emulsifying composition, it is preferred that the oil-in-water emulsifier of natural origin is chosen from: at least one alkyl polyglucoside; or at least a mixture of at least one alkyl polyglucoside and at least one fatty alcohol; or at least one non-ethoxylated fatty ester of polyols. more preferably, the emulsifier is chosen from mixtures of at least one alkyl polyglucoside and at least one fatty alcohol.

Emulsion, preferably of the Pickering type, using the emulsifying composition

The emulsifying composition according to the invention makes it possible to produce emulsions, preferably of the Pickering type, which can advantageously be stabilized by organic particles compatible with the skin or the hair. The so-called “pickering” emulsions are obtained by replacing the surfactants with emulsifying systems composed of solid microparticles in association with fatty substances.

Without wishing to be bound by any theory, it seems that the presence of very small amounts of an oil-in-water emulsifier of natural origin greatly facilitates the in situ formation of inclusion complexes between cyclodextrin and certain specific molecules present in the dispersed fatty phase, and this in the form of colloidal or solid particles, which are placed at the oil and water interfaces. These particles are very physically and sensory compatible with the skin or the hair and do not damage cell membranes.

The association of cyclodextrin with small amounts of an oil-in-water emulsifier of natural origin having a Hydrophilic-Lipophilic balance greater than or equal to 8, preferably greater than or equal to 9, makes it possible to obtain emulsions very stable with drops of size less than 30 pm, or even less than 10 pm.

The emulsifying composition according to the invention may additionally comprise other products capable of forming or stabilizing Pickering emulsions such as silicas and octenylsuccinate starches in the form of calcium or aluminum salts.

Another object of the present invention therefore relates to an emulsion, preferably of the oil-in-water (O / W) Pickering type, in particular for cosmetic use, characterized in that it contains at least one cyclodextrin in the form of solid particles, said particles having an average size in volume d (4.3) measured by laser granulometry, less than or equal to 20 pm, more preferably between 2 and 20 pm, preferably between 3 and 12 pm, and more preferably between 4 and 8 pm,

and at least one emulsifier of natural HLB origin greater than or equal to 8, preferably greater than or equal to 9, in an emulsifier / cyclodextrin ratio (weight / weight) of between 0.01: 1 and 1: 1, preferably between 0.15: 1 and 0.30: 1. Said emulsifier of natural origin is preferably chosen from alkyl polyglucosides, mixtures of at least one alkyl polyglucoside and at least one fatty alcohol, and non-ethoxylated fatty esters of polyols,

The emulsion, in particular from Pickering, using the emulsifying composition according to the invention, comprises an aqueous phase composed, in addition, of water.

According to an embodiment described as "rich in water", the water content in the emulsion is between 50% and 95%, preferably between 60% and 92%, very preferably between 65% and 90%, by weight relative to the total weight of the emulsion. The emulsion according to this embodiment is ready for use, and can therefore be used without adding additional water by the user.

According to an embodiment described as “poor in water”, the water content in the emulsion is between 2% and 50%, preferably between 5% and 35%, very preferably between 10% and 40%, by weight relative to the total weight of the emulsion. The emulsion according to this embodiment has the advantage of reducing the total mass of the containers such as flasks, bottles, or jars, by reducing the mass of water present in the emulsion. This reduces transport costs and the amount of exhaust gas released for this transport. The user may need to add water at the time of use to ensure proper use of this embodiment of the emulsion.

The emulsion, in particular of Pickering O / W, using the emulsifying composition according to the invention can also comprise a fatty phase which can be liquid at room temperature (25 ° C), such as for example vegetable oils , or solid as in the case of waxes. This liquid fatty phase can be of mineral, animal, vegetable or synthetic origin and be composed of hydrocarbon oils or possibly oils of silicones. The term “hydrocarbon-based oil” means an oil formed essentially, or even made up, of carbon and hydrogen atoms and optionally of oxygen or nitrogen atoms, which may contain alcohol, ester, ether, carboxylic acid, amine groups. and / or amide.

Preferably, the emulsion using the emulsifying composition according to the invention may comprise one or more oils, preferably at least one non-volatile liquid oil. The term “non-volatile liquid oil” is intended to mean an oil capable of remaining on the skin at ambient temperature, at atmospheric pressure for at least one hour.

The liquid fatty phase advantageously comprises one or more non-volatile oils which provide an emollient effect on the skin. Mention may be made of fatty esters such as cetearyl isononoate, isotridecyl isononoate, isostearyl isostearate, isopropyl isostearate, isopropyl myristate, isopropyl palmitate, butyl stearate , hexyl laurate, isononyl isononate, 2-ethyl-hexyl palmitate, 2-hexyldecyl laurate, 2-octyl decyl palmitate, myristate or 2-octyldodecyl lactate, succinate of 2-diethyl hexyl, diisostearyl malate, tracetin, tricprin, caprylic / capric acid triglycerides, glycerin triisostearate, tocopherol acetate, higher fatty acids such as myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, linoleic acid, linolenic acid or isostearic acid,, higher fatty alcohols such as oleic alcohol, vegetable oils such as l oil, camellia oil, hazelnut oil, tsubaki oil, cashew oil, arg oil year, soybean oil, grape seed oil, sesame oil, corn oil, wheat germ oil, rapeseed oil, sunflower oil, cottonseed oil, jojoba oil, peanut oil, olive oil and their mixtures, vegetable butters such as shea butter, camellia butter.

These oils can be oils of the hydrocarbon or silicone type such as paraffin oil, squalane oil, petrolatum, dimethyl siloxanes and their mixtures.

The liquid fatty phase can also optionally comprise volatile oils. By volatile oil is meant an oil capable of evaporating from the skin, in less than an hour at room temperature and atmospheric pressure. The volatile oils can for example be chosen from silicone oils or triglycerides of short fatty acids to reduce the greasy feel.

Preferably the emulsion type composition, in particular of Pickering O / W, using the emulsifying composition according to the invention contains only oils of renewable origin and in particular oils or butters of vegetable origin, preferably refined. These oils and butters are perfectly suited to the emulsifying system used in the emulsifying composition which is the subject of the invention in the sense that they make it possible to obtain very stable emulsions, with high whiteness and an easily adjustable viscosity. The emulsifying composition according to the invention advantageously makes it possible to prepare oil-in-water emulsions with very high oil content. This type of oil-rich O / W emulsion is usually difficult to obtain in a stable form over time with conventional emulsifiers. The oil content of the O / W emulsion using the emulsifying composition according to the invention is preferably between 10 and 65% by weight, and preferably of the order of 20 to 55% by weight, relative the total weight of the emulsion. Vegetable or vegetable oils such as, for example, sunflower oil and isopropyl palmitate make it possible in particular to obtain stable emulsions, not giving rise to creaming or phase shifting.

The emulsion using the emulsifying composition according to the invention may also comprise a rheology agent such as in particular a thickening agent for the aqueous phase, or a gelling agent or a suspending agent, such as for example the gums obtained plants such as gum arabic, konjac gum, guar gum or their derivatives; gums extracted from algae such as alginates or carrageenans; gums obtained from microbial fermentation such as xanthans, mannans, scleroglucans or their derivatives; cellulose and its derivatives such as carboxymethylcellulose or hydroxyethylcellulose; starch and its derivatives such as in particular modified starches, in particular acetylated, carboxymethylated, octenylsuccinates or hydroxypropylated; synthetic polymers such as polyacrylic acids or carbomers. Preferably, the emulsion using the emulsifying composition according to the invention comprises a rheology agent chosen from natural polysaccharides derived from plants or from fermentation, optionally modified. Xanthan and its derivatives make it possible in particular to obtain oil-in-water emulsions with very fine drop sizes, even when used at a content of less than 1% by weight, relative to the total weight of the emulsion.

The emulsions using the emulsifying composition according to the invention are preferably in the form of a fatty phase dispersed in an aqueous phase, said dispersed fatty phase being in the form of medium-sized drops. number less than or equal to 30 pm, preferably less than or equal to 10 pm.

A small drop size increases the stability of the emulsion by reducing the flocculation rate of the emulsion, and therefore the speed of phase separation. The average drop size depends on a large number of parameters and, as such, constitutes a characteristic which should be controlled and which is not intrinsic to the formulation of the emulsifying composition.

The average drop size can be measured using a LEICA DMLS optical microscope at x10 magnification, followed by counting and calculating a number average over at least ten drops.

The emulsion using the emulsifying composition according to the invention may further comprise a preservative chosen from benzyl alcohol, dehydroacetic acid and their mixtures.

The emulsion using the emulsifying composition according to the invention preferably has a viscosity greater than 3000 mPa.s at 25 ° C, preferably greater than 5000 mPa.s at 25 ° C. The viscosity is measured using a Brookfield DV-11 + Pro viscometer rotated at a speed of 20 rotations per minute in contact with the product sample. The resistance of the product to this rotational movement is recorded for one minute and converted to "mPascal. second ”, usually noted mPa.s. For each sample, the viscosity is measured three times and the arithmetic mean of the three values is used. In order to characterize the sensory properties of the emulsifying compositions according to the invention, sensory descriptors and a corresponding sensory evaluation protocol are used in 5 steps. These 5 stages correspond to the different phases of application of a skincare product: appearance, handling, application, spreading after 1 minute, and spreading after 2 minutes. During these 5 phases, several sensory descriptors are evaluated by a panel of ten evaluators, in order to compare an emulsion according to the invention to an emulsion according to patent application FR1853362 filed by the present applicant. The emulsions according to the invention are distinguished from the emulsions according to patent FR1853362 on the sensory properties of fluidity, powder, spreading, greasy, soft, crunching, penetrating, and fluffing. The emulsions according to the invention provide a less fluid texture, but all the same easier to spread and which penetrates more quickly, as well as a more oily feel, but all the same more powdery, softer and less crunchy. In addition, there are fewer or no fluff depending on the skin.

In addition, the emulsifying composition according to the invention allows the easy production of oil-in-water O / W emulsions which are both very stable and very fine, with modular textures and having a fresh, silky touch and little fatty, even for high contents in dispersed fatty phase. It is thus possible to obtain emulsions having a good emollient effect on the skin as well as a good hydrating effect of the upper layers of the epidermis.

This emulsifying composition in particular allows the easy production of very fine O / W emulsions with varied textures, very compatible with the skin and also having a dry, fresh and silky feel, even with a high content. in the fatty phase in the emulsion.

Method of manufacturing a liquid emulsion using the emulsifying composition

Another object of the present invention consists of a process for manufacturing a liquid oil-in-water emulsion, preferably from Pickering, in particular for cosmetic use, comprising the following steps:

a) the dispersion, in an aqueous phase, of an emulsifying composition comprising at least one cyclodextrin in the form of solid particles, said particles having a volume average size d (4.3) measured by laser particle size, between 2 and 20 μm, preferably between 3 and 12 μm, and more preferably between 4 and 8 μm, and at least one original emulsifier natural chosen from oil-in-water emulsifiers, having an HLB greater than or equal to 8, and more preferably an HLB greater than or equal to 9, in an emulsifier / cyclodextrin ratio of between 0.01: 1 and 1: 1, preferably between 0.15: 1 and 0.30: 1,

b) adding to the mixture obtained in step a) a fatty phase, in an amount of between 10 and 65% by weight, relative to the total weight of the composition, with stirring to allow the dispersion of the phase fatty in the aqueous phase in the form of drops of average size in number less than 30 pm, preferably less than or equal to 10 pm.

According to a variant, the method according to the invention for manufacturing a liquid oil-in-water emulsion, preferably of the Pickering type, in particular for cosmetic use, comprises the following steps:

a) the dispersion, in a fatty phase, of an emulsifying composition comprising at least one cyclodextrin in the form of solid particles, said particles having a volume average size d (4.3) measured by laser particle size, between 2 and 20 pm, preferably between 3 and 12 pm, and more preferably between 4 and 8 pm,

and at least one emulsifier of natural origin chosen from oil-in-water emulsifiers, having an HLB greater than or equal to 8, and more preferably an HLB greater than or equal to 9, in an emulsifier / cyclodextrin ratio of between 0.01 : 1 and 1: 1, preferably between 0.15: 1 and 0.30: 1, the fatty phase preferably representing between 10 and 65% by weight, and preferably between 20 and 55% by weight, relative to the final weight of the emulsion,

b) and adding the mixture obtained in step a) to an aqueous phase with stirring to allow the dispersion of the fatty phase in the aqueous phase in the form of drops of average size in number less than 30 μm, preferably less or equal to 10 pm. In the two variants of the process for manufacturing an oil-in-water emulsion, preferably from Pickering, described above, it is preferred to use an emulsifying composition according to the invention, the original emulsifier natural is chosen from at least one alkyl polyglucoside, at least one mixture of at least one alkyl polyglucoside and at least one fatty alcohol, and at least one non-ethoxylated fatty ester of polyols, more preferably chosen from mixtures of at least one alkyl polyglucoside and at least one fatty alcohol.

Use

Finally, the invention also relates to the use:

of a cyclodextrin in the form of solid particles having a volume average size d (4.3) measured by laser particle size, less than or equal to 20 μm, more preferably between 2 and 20 μm, preferably between 3 and 12 μm , and more preferably between 4 and 8 pm,

-and at least one emulsifier of natural origin chosen from emulsifiers of the oil-in-water type, having a Hydrophilic-Lipophilic balance greater than or equal to 8, most preferably greater than or equal to 9, the HLB of the whole of the emulsifying system of said composition also being greater than or equal to 8, preferably greater than or equal to 9,

in an emulsion for cosmetic use to give said emulsion a softer and more powdery feel, and to reduce or eliminate fluff.

Examples

The invention can be better understood using the non-limiting exemplary embodiment described below.

Example 1: emulsion

A “reference” emulsion prepared with an emulsifying composition containing a beta-cyclodextrin marketed under the name “Beauty by Roquette® CD102” by the applicant, whose volume average diameter is 94.83 μm, is compared with an emulsion according to the invention, which is obtained by using this same beta-cyclodextrin previously ground dry to have an average size by volume d (4.3) of less than 12 μm: the beta-cyclodextrin thus obtained is described as “ultra-fine” . Characteristics The particle sizes of these two beta-cyclodextrins are presented in Table 1.

[Table 1]

[Table 2]

The two emulsions of table 2 above are prepared according to the following protocol.

We start by dispersing a gelling agent in water with stirring with a pale deflocculation at 1000 revolutions per minute. The water temperature is set at 40 ° C when the gelling agent is xanthan gum, and at 70 ° C when the gelling agent is hydroxyethylcellulose.

The beta-cyclodextrin is then wetted in glycerin and the beta-cyclodextrin / glycerin mixture is added to the water / gelling agent mixture with stirring 1000 rpm, in order to obtain an aqueous phase.

The amount of beta cyclodextrins is fixed at 5% by mass of the composition.

Separately, the alkyl polyglucoside MONTANOV L (INCI: cetearyl alcohol & cetearyl glucose), from the company SEPPIC, is added in sunflower oil or in isopropyl palmitate with magnetic stirring, at 40 °. C to obtain an oily phase. The oily phase is then emulsified in the aqueous phase at 40 ° C with stirring at 1500 rpm, for 15 minutes.

A preservative (mixture based on benzyl alcohol and dehydroacetic acid) is added.

For each of the emulsions, physicochemical characteristics are measured, namely the viscosity and the average size in number of the drops, and sensory characteristics are measured, namely slippery, spreading, fat, softness, crunching, penetrating, powdery and fluffy.

The viscosity is measured using a Brookfield DV-ll + Pro viscometer. A fixed-size mobile (mobile SP2 to SP7 used according to the viscosity levels in accordance with the instructions of the device) is rotated at a speed of 20 revolutions per minute in contact with the sample produced. The resistance of the product to this rotational movement is recorded for one minute and converted to millipascal seconds. For each sample, the viscosity is measured three times and the arithmetic mean of the three values is used. A spindle suitable for the viscosity measured is selected according to the following ranges: the spindle chosen is the spindle SP3 when the viscosity is less than or equal to 5,000 mPa.s, SP4 when the viscosity is between 5,000 mPa.s and 7,000 mPa.s and SP5 when the viscosity is greater than or equal to 7000 mPa.s.

The number average size of the drops is determined by performing the arithmetic average of the drop sizes measured with an optical microscope at 10 × magnification, on a representative number of drops, typically at least 10 drops. The microscope used is a LEICA DMLS.

The sensory characteristics are evaluated by a panel of ten people who are experts in the analysis of the texture of cosmetic products.

When spreading the product, two descriptors are evaluated. The examination of the product is done under the lamp, after having deposited on the hand 50 to 100 μL of the product studied, during its spreading in 10 rotations.

-The powdery descriptor is evaluated between the 2nd and the 5th rotation. The fingers glide well on the skin. The product is perceived as a powdery substance on the skin. -The spreading is evaluated by examining the product after having deposited on the hand 50 to 100 μL of the product, during its spreading in 10 rotations, under a lamp. The spread is all the more important as there is little resistance to movement between the 5 th and the 10 th turn on the hand.

The last descriptors are evaluated after performing the 10 rotations.

For the following two descriptors, the examination is carried out under the lamp, on the skin, 1 minute after the product has been spread 50 to 100mI.

-The soft descriptor is evaluated by sliding on the skin, a dry and slippery touch is felt.

-The crunching descriptor is evaluated by sliding the thumb over the index finger, a brake is felt and a creaking noise is heard.

For the following two descriptors, the examination is carried out under the lamp, on the skin, 2 minutes after the spreading of 50 to 100 μL of the product.

-The penetrating descriptor of the product is evaluated by sliding it over the skin. A panel of assessors then assesses the amount of product residue recovered.

-The fluff is evaluated by performing a mechanical friction action on the skin, the product causes the formation of fluff.

The two emulsions have substantially equal viscosities, around 12,000 mPa.s, and have drop sizes less than 10 μm.

Table 3 presents the sensory perceptions obtained with the emulsion prepared with the emulsifying composition according to the invention, compared to the sensory perceptions obtained with an emulsion prepared with a reference emulsifying composition.

The criteria of improved sensory properties in the emulsion according to the invention are: powdered, spreading, fatty, soft, crunchy, penetrating, fluffing.

[0110] [Table 3]

Claims

[Claim 1] Emulsifying composition, preferably for cosmetic use, capable of making it possible to obtain an emulsion of the oil-in-water type, comprising:

a) at least one cyclodextrin in the form of solid particles, said particles having a volume average size d (4.3) measured by laser particle size, between 2 and 20 μm, preferably between 3 and 12 μm, and more preferably between 4 and 8 pm,

b) and at least one emulsifier of natural origin chosen from emulsifiers of the oil-in-water type, having a hydrophilic-lipophilic balance greater than or equal to 8, most preferably greater than or equal to 9.

[Claim 2] Emulsifying composition according to claim 1, characterized in that the cyclodextrin particles have a size distribution in volume, measured by particle size by laser diffraction, whose characteristic diameters d (10), d (50) and d ( 90) are such that:

a) The diameter d (10) is less than or equal to 5.0 pm, preferably less than or equal to 2.5 pm, and / or

b) the diameter d (50) is less than or equal to 15.0 pm, preferably less than or equal to 10.0 pm, and / or

c) the diameter d (90) is less than or equal to 30.0 µm, preferably less than or equal to 25.0 µm.

[Claim 3] Emulsifying composition according to one of the preceding claims, characterized in that the solid particles of cyclodextrin have a size distribution by volume, measured by particle size by laser diffraction, having a coefficient of variation less than or equal to 100%, preferably less than or equal to 90%, and most preferably less than or equal to 73%.

[Claim 4] Emulsifying composition according to one of the preceding claims, characterized in that said at least one original emulsifier natural has a Hydrophilic-Lipophilic balance (HLB) of between 8 and 20, preferably between 9 and 16, and better still between 1 1 and 14.

[Claim 5] Emulsifying composition according to one of the preceding claims, in which the average HLB of the entire emulsifying system of said composition is greater than or equal to 8, preferably greater than or equal to 9.

[Claim 6] Emulsifying composition according to one of the preceding claims, characterized in that the emulsifier of natural origin is present in the emulsifying composition in an emulsifier / cyclodextrin ratio of between 0.01: 1 and 1: 1, preferably between 0.05: 1 and 0.5: 1, more preferably between 0.10: 1 and 0.35: 1 and better still between 0.15: 1 and 0.30: 1.

[Claim 7] Emulsifying composition according to one of the preceding claims, characterized in that said cyclodextrin is chosen from alpha-, beta- and gamma-cyclodextrins, preferably is a native beta-cyclodextrin.

[Claim 8] Emulsifying composition according to any one of the preceding claims, in which the emulsifier of natural origin is an oil-in-water emulsifier chosen from: alkyl polyglucosides; mixtures of at least one alkyl polyglucoside and at least one fatty alcohol; non-ethoxylated fatty esters of polyols, especially from fatty esters of glycerol, polyglycerols, sorbitol, sorbitan, anhydrohexitols, preferably from fatty esters of isosorbide, mannitol, xylitol, erythritol, maltitol, sucrose, glucose, polydextrose, hydrogenated glucose syrups, dextrins and hydrolyzed starches.

[Claim 9] Emulsifying composition according to any one of the preceding claims, in which the emulsifier of natural origin is an oil-in-water emulsifier chosen from C12-C20 alkyl polyglucosides, of general formula (I) below: R1 -0- (R2-0) p- (S) n in which:

-R1 denotes a linear or branched alkyl and / or alkenyl radical containing approximately from 12 to 20 carbon atoms -R2 denotes an alkylene radical containing from 2 to 4 carbon atoms,

-p takes a value ranging from 0 to 3, and preferably equal to zero,

-S denotes glucose, fructose or galactose, and more preferably glucose,

-n denotes a value ranging from 1 to 15

[Claim 10] Emulsifying composition according to claim 8, in which the O / W emulsifier of natural origin is a mixture consisting of at least one alkyl polyglucoside and at least one fatty alcohol, preferably at least one alkyl C12-C20 polyglucoside and at least one linear or branched fatty alcohol having a total number of carbon atoms ranging from 8 to 24, and most preferably a mixture of C14-C22 fatty alcohol and alkyl glucoside C12-C20.

[Claim 11] Emulsifying composition according to any one of the preceding claims, comprising:

a) 40% to 95% of at least one cyclodextrin in the form of solid particles, said particles having a volume average size d (4.3) measured by laser particle size, between 2 and 20 μm, preferably between 3 and 12 pm, and more preferably between 4 and 8 pm,

b) 5% to 40% of at least one emulsifier of natural origin chosen from emulsifiers of the oil-in-water type, having a Hydrophilic-Lipophilic balance greater than or equal to 8, most preferably greater than or equal to 9, c ) And 0% to 40% of at least one polyol.

[Claim 12] Liquid emulsion, preferably from oil-in-water Pickering, characterized in that it contains at least one cyclodextrin in the form of solid particles, said particles having a volume average size d (4.3) of between 2 and 20 pm, preferably between 3 and 12 pm, and more preferably between 4 and 8 pm, and at least one emulsifier of natural origin chosen from emulsifiers of the oil-in-water type, having a higher hydrophilic-lipophilic balance or equal to 8, most preferably greater than or equal to 9, in an emulsifier / cyclodextrin ratio of between 0.01: 1 and 1: 1, preferably between 0.15: 1 and 0.30: 1.

[Claim 13] Emulsion according to Claim 12, characterized in that it is in the form of a fatty phase dispersed in an aqueous phase, the said dispersed fatty phase being in the form of drops of average size in number less than 30 pm, preferably less than or equal to 10 pm.

[Claim 14] Composition according to any one of the preceding claims, having a viscosity greater than 3000 mPa.s at 25 ° C, preferably greater than 5000 mPa.s at 25 ° C.

[Claim 15] Method for manufacturing a liquid emulsion, preferably an oil-in-water pickering, comprising the following steps:

a) the dispersion, in an aqueous phase, of an emulsifying composition comprising at least one cyclodextrin in the form of solid particles, said particles having a volume average size d (4.3) measured by laser particle size, between 2 and 20 pm, preferably between 3 and 12 pm, and more preferably between 4 and 8 pm,

and at least one emulsifier of natural origin chosen from emulsifiers of the oil-in-water type, preferably having a Hydrophilic-Lipophilic balance greater than or equal to 8, most preferably greater than or equal to 9, in an emulsifier / cyclodextrin ratio comprised between 0.01: 1 and 1: 1, preferably between 0.15: 1 and 0.30: 1,

[Claim 16] Joint use of a cyclodextrin in the form of solid particles having a volume average size d (4.3) measured by laser particle size, between 2 and 20 μm, preferably between 3 and 12 μm, and more preferably between 4 and 8 pm,

and at least one emulsifier of natural origin chosen from emulsifiers of the oil-in-water type, having a hydrophilic-lipophilic balance greater than or equal to 8, most preferably greater than or equal to 9, in an emulsion with cosmetic use to give said emulsion a softer and more powdery feel, and to reduce or eliminate fluff.