FR2944458A1 - Preparing oil-in-water emulsion by directly/phase inversion, useful e.g. to treat fungal infections, comprises preparing phase A having e.g. xanthan, stirring phase, preparing aqueous phase B, adding phases and stirring - Google Patents

Abstract

Preparation of an oil-in-water emulsion by directly/by phase inversion, comprises: (a) preparing a phase A comprising elements having xanthan, at least one non-ionic, anionic, cationic or amphoteric type surface agent and their mixture and at least one lipophilic fluid; (b) stirring the phase A to make it homogeneous, at a stirring speed of 5-250 (preferably less than 50) rpm; (c) preparing an aqueous phase B, at 20-50[deg] C; (d) adding the phase A to the phase B by stirring at 20-50[deg] C for 5-30 (preferably 10) minutes; and (e) maintaining stirring to obtain stable oil-in-water emulsion. Independent claims are included for: (1) a composition comprising (i) xanthan, (ii) at least one ionic, anionic, cationic or amphoteric type surface agent, and (iii) at least one lipophilic liquid; (2) a preparation of the oil-in-water emulsion by direct way, comprising adding the composition in an aqueous phase by stirring at a temperature of 20-50[deg] C and maintaining the stirring to obtain stable oil-in-water emulsion; and (3) a preparation of the oil-in-water emulsion by reverse phase, comprising adding aqueous phase into the composition by stirring at a temperature of 20-50[deg] C and maintaining the stirring to obtain stable oil-in-water emulsion. ACTIVITY : Dermatological; Fungicide. MECHANISM OF ACTION : None given.

Description

Process for manufacturing an oil-in-water emulsion by direct and indirect cold and low agitation

The invention relates to a method for manufacturing a cosmetic, pharmaceutical or food emulsion, oil-in-water, directly or indirectly, cold and with low agitation for a short time, said emulsion comprising xanthan gum ( or xanthan) as a gelling agent, at least one nonionic, anionic, cationic and / or amphoteric surfactant, and at least one lipophilic liquid.

Thickeners or gelling agents are frequently used in the manufacture of cosmetic or pharmaceutical products, in particular emulsions, in order to modify the viscosity, to improve the stability or the substantivity of the products.

The thickeners or gelling agents in the emulsions limit the creaming phenomena which guarantees a longer shelf life, and also prevents the sedimentation of the particles while allowing easy use of the product by the consumer. However, these thickeners or gelling agents require a particular implementation at the level of the process since they tend to be poorly dispersible in the compositions, in particular in emulsions, and even more particularly in oil-in-water emulsions, which leads for example to incomplete gelation and / or instability of the emulsion.

The prior art has partially solved this problem by dispersing these thickeners or gelling agents by means of strong energetic agitation systems such as deflocculators, associated with a consequent heat input during mixing operations.

One of the problems encountered by this technique is the low reproducibility of the operating conditions, depending on the material, or the temperature used. In particular one of the consequences is a poor reproducibility batches of the same product to another depending on the energy developed by the agitation motor during manufacture.

In order to solve the dispersion problem of the gelling agent, the prior art also describes compositions containing, in addition to the gelling agent, a lipophilic liquid whose role is to allow a better dispersion of the gelling agent during the manufacture of the products.

However, the gelling agents used in the prior art in combination with the lipophilic liquid belong to the category of acrylic derivatives. These acrylic derivatives are sensitive to the ionic environment and can not be used in all product developments.

Conversely, the present invention is concerned with a particular gelling agent, xanthan gum, which in combination with a lipophilic liquid is capable of thickening liquids or of gelling an emulsion in a high pH range in the presence of high concentration. ionic. In addition, the Applicant has shown that the use of xanthan gum as a gelling agent in a cosmetic or pharmaceutical oil-in-water emulsion could solve the problem of the reproducibility of the operating conditions, since it did not require strong agitation for a long time, nor did it require important thermal contribution.

International patent application WO 2007/091016 describes a method for preparing an oil-in-water emulsion comprising the following steps: a) dispersion of a non-ionic surfactant and a combination of xanthan and polyglucomannan (xanthan + polyglucomannan combination in concentrations ranging from 0.02 to 0.5% by weight of the emulsion obtained) in an oil or a nonaqueous liquid medium, b) mixing of the water with the oily phase obtained at 1 step a), preferably at low temperature and under low shear mechanical energy, to form an oil-in-water emulsion, and c) mixing the obtained emulsion, preferably with gentle stirring, until homogenization. The peculiarity of the presumed invention described in this document is the use of nonionic surfactant in combination with xanthan gum and polyglucomannan, as well as an oil, in order to obtain a stable oil-in-water emulsion. an indirect method at a temperature below 50 ° C and a stirring less than 5000s 1.

The method described does not allow the production of stable emulsion if this process is direct (Examples 4 and 7). This document teaches that anionic, cationic and amphoteric surfactants are not desirable in emulsions (page 9 lines 4 9). Finally, the method described does not allow the development of stable emulsion at ionic concentrations greater than 0.05 moles. In addition to reading this document, it is not possible to determine the concentration of xanthan, which is always in association with polyglucomannan, the concentration of the association of the two molecules being between 0.02 and 0. , 5%, and the xanthan / polyglucomannan ratio not being specified. However, those skilled in the art can deduce that the xanthan concentrations to be used are low to very low and in any case much less than 0.5% by weight of the final composition.

Surprisingly and unexpectedly, and contrary to the technical prejudices issued by the document WO 2007/091016, the applicant has shown that it is possible to obtain stable oil-in-water cosmetic or pharmaceutical emulsions by means of a method of direct or indirect manufacture with cold and low agitation, said emulsion comprising xanthan gum as a gelling agent at high concentrations, at least one nonionic, anionic, cationic or amphoteric surfactant and mixtures thereof, and The present invention makes it easier to use xanthan gum in cosmetic or pharmaceutical preparations since it is not necessary to provide during the emulsion manufacturing process a strong stirring energy during the preparation of the emulsion. a long time to obtain an optimal dispersion of xanthan. Indeed, when the xanthan gum is dispersed in the composition containing at least one lipophilic liquid, it is capable of diffusing slowly through this liquid to join the aqueous phase and either thicken the product or form a stable and homogeneous gelled network.

The process according to the invention The invention relates to a process for manufacturing an oil-in-water emulsion directly, characterized in that it comprises, preferably contains, the following steps: a) preparation of a phase A, comprising the following elements: xanthan, - at least one nonionic, anionic, cationic or amphoteric surfactant; and at least one lipophilic liquid; b) stirring of the phase A until homogenization, preferably at a stirring speed of between 5 and 250 rpm and more preferably at a stirring speed of less than 50 rpm; c) preparing an aqueous phase B, preferably at a temperature between 20 and 50 ° C; d) addition of phase A to phase B with stirring at a temperature between 20 ° C and 50 ° C for a period of between 5 and 30 minutes, preferably between 5 and 20 minutes, more preferably between 5 and 10 minutes, and even more preferably for a period of 10 minutes; and e) maintaining stirring until a stable oil-in-water emulsion is obtained.

Preferably, the process according to the invention is characterized in that the stirring in step b) is carried out at a temperature of between 20 and 50 ° C. Preferably, the process according to the invention is characterized in that the stirring in steps b), d) and e) is carried out using a turbine.

The invention also relates to a process for producing an oil-in-water phase-inversion emulsion, characterized in that it comprises, preferably contains, the following steps: a) preparation of a phase A, comprising the the following elements: xanthan, at least one surfactant of nonionic, anionic, cationic or amphoteric type; and - at least one lipophilic liquid; b) stirring of phase A until homogenization, preferably at a stirring speed of between 5 and 250 rpm and more preferably at a stirring speed of less than 50 rpm; c) preparing an aqueous phase B, preferably at a temperature between 20 and 50 ° C; d) adding phase B to phase A with stirring at a temperature of between 20 ° C. and 50 ° C. for a period of between 5 and 30 minutes, preferably between 5 and 20 minutes, more preferably between 5 and 10 minutes, and even more preferably for a period of 10 minutes; and e) maintaining stirring until a stable oil-in-water emulsion is obtained. Preferably, the process according to the invention is characterized in that stirring in step b) is carried out at a temperature of temperature between 20 and 500C.

Preferably, the method according to the invention is characterized in that the stirring in steps b), d) and e) is done using a turbine.

By "method of manufacturing a direct oil-in-water emulsion" is meant the manufacture of an oil-in-water direct emulsion by adding the oily phase in the aqueous phase.

By "method of manufacturing an oil-in-water emulsion indirectly" is meant the manufacture of an oil-in-water emulsion by adding the aqueous phase in the oily phase.

By "emulsion" is meant a heterogeneous system of two immiscible liquids, generally an aqueous phase and a lipophilic liquid phase of which one of the two phases is dispersed in the other in the form of fine droplets, the whole being homogeneous to the naked eye. The success of an emulsion depends on:> The nature of the ingredients> The water, oil and surfactant ratio> Methods of preparation.

By "oil-in-water emulsion" is meant a stable emulsion composed of an oily phase dispersed in an aqueous phase by direct route or by phase inversion.

Phase A

By "xanthan" is meant a polysaccharide obtained by fermentation of Xanthomonnas campestris and whose main chain is constituted by a chain of glucopyranoses linked to each other by β1,4 glucosidic bonds (cellulose) on which all of them are grafted. the 2 glucose residues a side chain constituted by 2 residues of mannopyranoses framing 1 residue of glucuronic acid.

In another embodiment of the invention, the xanthan may be replaced or used with an exopolysaccharide from bacterial fermentation such as gellan.

By "surfactant", or surfactant, detergent, surfactant, emulsifier or emulsifier, is meant any substance having the property of adsorbing at the interfaces and thus of reducing the interfacial tensions. Since the properties of surfactants are determined by their structure, the fundamental character of these products is amphiphilism, that is to say the presence in the molecule of two groups having completely different solubility characteristics: oil, called `lipophilic '> A group that is soluble in water, called` hydrophilic' The surfactants are mainly used for their specific properties which make it possible to make dispersions, in particular emulsions. Indeed, surfactants are substances that lower the surface tension of the medium in which they are dissolved. They can be fat-soluble or water-soluble. Anionic, cationic, amphoteric and nonionic surfactants are distinguished. The choice of surfactants depends, inter alia, on their compatibility with the chosen lipophilic liquid and the polarity of the medium in which they are located. In the context of this invention, preference will be given to anionic, cationic and amphoteric surfactants. "Nonionic surfactants" means a surfactant having no net charge. By way of example, mention may be made of polysorbate or sucrose ester, alkylpolygluciside or glycerol ester.

By "anionic surfactants" is meant a surfactant having one or more functional groups ionizing in aqueous solution to provide negatively charged ions. By way of examples, mention may be made of:> Alkylbenzene sulfonate,> Sulphated alcohols,> Alkyl sulphate, - Sulfated ethoxylated alcohols,> Phosphate derivatives.

By "cationic surfactant" is meant a surfactant having one or more functional groups ionizing in aqueous solution to provide positively charged ions.

By way of examples, mention may be made of: Quaternary ammonium, Tertiary amines.

By "amphoteric surfactant" is meant a surfactant which, depending on the pH of the medium in which they are, releases either a positive ion or a negative ion. In alkaline media, amphoteric surfactants behave as anionic surfactants. In acidic media, amphoteric surfactants behave like cationic surfactants. Examples include:> Lecithin,> Betaines.

In a preferred manner according to the present invention, the phase A, and thus the emulsion obtained by this method, do not contain nonionic surfactant.

In the context of this invention, preference will be given to anionic surfactants.

By "lipophilic" is meant the property that a substance is compatible with a lipid, i.e. can accept a lipid, a fat or an oil, to form with them a homogeneous phase. By hydrophilic is meant the property that a substance is compatible with water, that is to say can absorb or attract water, or dissolve.25 By "heating" of phase A is meant the supply of thermal energy to bring phase A to a temperature between 20 ° C and 50 ° C. By "agitation" is meant the supply of mechanical energy 5 for example by means of a turbine.

The stirring during step b) of the process according to the invention is carried out for example a planetary mixer, at a speed of 5 rpm at 1200 rpm. This is therefore a low stirring speed.

By "gellan" is meant a polysaccharide produced by fermentation of Sphingomonas elodea, more commonly referred to as Pseudomonas elodea. This linear polysaccharide is constituted by the sequence of the following monosaccharides: D-Glucose, D-glucuronic acid and L-Rhamnose.

Preferably, the process according to the invention is characterized in that the xanthan used in phase A is in concentrations ranging from 0.01% to 5% by weight relative to the total weight of the emulsion obtained according to said process, preferably ranging from 0.1% to 5% by weight, and more preferably from 0.5% to 1.5% by weight.

Preferably, the process according to the invention is characterized in that the surfactant used in phase A is in concentrations ranging from 0.01% to 10% by weight relative to the total weight of the emulsion obtained according to said process, preferably from 0.1% to 5% by weight, preferably from 1% to 3% by weight, preferably between 1% and 2% by weight and more preferably between 0.3 and 0.75% by weight.

Preferably, the process according to the invention is characterized in that the surfactant used in phase A is chosen from the group consisting of cocoglucoside, laurylglucoside, Polyglyceryl-3 Diisostearate and Sodium Lauroyl Glutamate.

Preferably, the process according to the invention is characterized in that the lipophilic liquid used in phase A is in concentrations ranging from 0.01% to 10% by weight relative to the total weight of the emulsion obtained according to said process, preferably from 0.1% to 5% by weight, preferably from 1% to 3% by weight, preferably between 1% and 2% by weight and more preferably between 0.3 and 0.75% by weight. The process according to the invention is characterized in that the surfactant used is an oil-in-water emulsifier, characterized by HLB values greater than 6 according to the Griffin scale. By "oil-in-water emulsifier" is meant a surfactant for producing oil-water emulsions.

By "HLB", or "hydrophilic-lipophilic balance" is meant a dimensionless size reflecting the relative importance of the polar and apolar moieties of a surfactant, which conditions the relative affinity of the surfactant. for water and for organic media. This concept applies to nonionic surfactants but may to some extent be extended to ionic surfactants. HLB is an arbitrary scale of 0-20, admitting that products with HLB 0-10 are lipophilic and HLB 10-20 are hydrophilic. In order to obtain an oil-in-water emulsion, it is advisable to use a surfactant whose HLB is generally greater than 6. Preferably, the process according to the invention is characterized in that the lipophilic liquid used in phase A is an oil selected from the group consisting of hydrocarbon oils, linear or branched hydrocarbons, vegetable oils, silicone oils, fluorinated oils, and mixtures thereof, or an emollient selected from the group comprising esters, ethers , Guerbet alcohols, glycerides and mixtures thereof, or the mixture of a said oil or a so-called emollient

More preferably, the lipophilic liquid used in the process according to the invention is a vegetable oil.

Even more preferably, the lipophilic liquid used in the process according to the invention is sunflower oil.

By "oil" is meant a fat mainly consisting of triglycerides, which is liquid at room temperature. Among the oils used in the context of this invention, mention may be made of: hydrocarbon-based oils, such as esters and synthetic ethers, for example purcellin oil, isononyl isononanoate, myristate, isopropyl, 2-ethylhexyl palmitate, octyl-2-dodecyl stearate, octyl-2-dodecyl erucate, isostearyl isostearate; hydroxylated esters such as isostearyl lactate, octyl hydroxystearate, octyldodecyl hydroxystearate, diisostearyl malate, triisocetyl citrate, heptanoates, octanoates, decanoates of fatty alcohols; polyol esters, such as propylene glycol dioctanoate, neopentyl glycol diheptanoate and diethylene glycol diisononanoate; pentaerythritol esters such as pentaerythritol tetraisostearate; lipophilic derivatives of amino acids, such as isopropyl lauroyl sarcosinate; linear or branched hydrocarbons of mineral or synthetic origin, such as mineral oils, paraffin oils, volatile or not, and their derivatives, petroleum jelly, polydecenes, isohexadecane, isododecane, isoparaffine hydrogen; - vegetable oils, such as coconut oil, palm oil, sweet almond oil, olive oil, sunflower oil, avocado oil, oil castor oil, walnut oil, soybean oil, peanut oil, reason seed oil; silicone oils, such as volatile or non-volatile silicone polymers, linear or cyclic, which are liquid at ambient temperature, in particular cyclopolydimethylsiloxanes (cyclomethicones) such as cyclopentasiloxane and cyclohexadimethylsiloxane; polydimethylsiloxanes comprising alkyl, alkoxy or phenyl groups, during or at the end of the silicone chain, groups having from 2 to 24 carbon atoms; phenyl silicones such as phenyltrimethicones, phenyldimethicones, phenyltrimethylsiloxydiphenylsiloxanes, diphenyl-dimethicones, diphenylmethyldiphenyltrisiloxanes, 2-phenylethyltrimethylsiloxysilicates, and polymethylphenylsiloxanes; fluorinated oils, such as those partially hydrocarbon and / or silicone; > their mixtures.

By "emollient" is meant a substance which helps to relax the tissues, to calm the inflammation and to soften the skin. The emollients used in the context of this invention are liquid at room temperature. Among the emollients that can be used in the context of this invention include:> esters and ethers, such as decyloleate, myristyl myristate, isopropyl palmitate, isopropyl myristate, dicaprylether; > Guerbet alcohols, such as octyldodecanol; glycerides, such as derivatives of capric / caprylic acid.

Preferably, the process according to the invention is characterized in that phase A represents from 5% to 80% by weight relative to the total weight of the emulsion obtained according to said process, preferably from 5% to 50%, and more preferentially from 5% to 30% by weight.

Phase B By "aqueous phase" is meant water or a solution mainly comprising water, with additives of vegetable, mineral or synthetic origin.

By "preparation of the aqueous phase B" is meant in the case where the phase B is only water, the provision of water (for example in a suitable container) and in the case where the phase B is additive water is understood to mean the mixing of water and its additives, followed by the provision of phase B (for example in the adapted container).

Preferably, the process according to the invention is characterized in that the aqueous phase B represents from 20% to 95% by weight relative to the total weight of the emulsion obtained according to said process, preferably ranging from 50% to 95% by weight. and more preferably from 70% to 95% by weight.

Preferably, the process according to the invention is characterized in that step d) is carried out under agitation of between 600 and 1600 rpm, preferably 800 to 1400 rpm, preferably by means of a turbine.

Preferably, the method according to the invention is characterized in that it contains an additional step of adding a preservative agent to phase A during step a), during step b), to the phase B during step c), during step d), during step e) or after step e). More preferably, the addition of the preservative is done in step e) 10 to 15 minutes after step d) of adding phase A in phase B. By "preservative agent", it is means an additive inhibiting the development of microorganisms. Preservatives fall into two categories:> antiseptics which protect the aqueous phases from bacterial and fungal contaminations, and> antioxidants which retard the phenomena of rancidity.

Preferably, the process according to the invention is characterized in that the preserving agent used is a mixture of phenoxyethanol, methyl paraben, ethylparaben, propylparaben and butylparaben (Sepicide HB).

Preferably, the process according to the invention is characterized in that it contains an additional step of adding a cosmetically acceptable agent in the case where the emulsion is an emulsion for cosmetic use, a pharmaceutically acceptable agent in the case where the emulsion is an emulsion for pharmaceutical use and a food agent in the case where the emulsion is an emulsion for food use. The agents are added to phase A during step a), during step b), to phase B during step c), during step d), during step e ) or after step e). More preferably, the addition of the cosmetically acceptable agent takes place before or after the addition of the preservative.

By "cosmetically acceptable agent", or "pharmaceutically acceptable agent" is meant a compound capable of having an activity, in the context of a cosmetic or therapeutic use. Preferably, the agents used in the context of this invention are intended for topical use.

In the context of this invention, the cosmetically or pharmaceutically acceptable agent is for example chosen from. desquamating agents capable of acting either by promoting exfoliation or on the enzymes involved in desquamation or degradation of corneodesmosomes, moisturizing agents, depigmenting or propigmenting agents, anti-glycation agents, inhibitors of NO-synthase, - 5alpha -reductase inhibitors, - lysyl and / or prolyl hydroxylase inhibitors, - agents stimulating the synthesis of dermal or epidermal macromolecules and / or preventing their degradation,> agents stimulating the proliferation of fibroblasts or keratinocytes and / or the differentiation of keratinocytes,> myorelaxing agents, - antimicrobial agents, - tensing agents, - anti-pollution or anti-radical agents,> anti-inflammatory agents,> lipolytic active agents or having a favorable activity, direct or indirect, on the decrease of the adipose tissue, the agents acting on the microcirculation, and the agents acting on the energetic metabolism of cells, the photoprotective agents, ie any compound or combination of compounds which allow absorption, reflection or diffusion of UV-A or UV-B radiation, preservatives, perfumes,> bactericides, odor absorbers, dyestuffs, salts, surfactants, thickeners, bases.

The amounts of these various agents are those conventionally used in the field under consideration, and for example from 0.01 to 20% of the total weight of the composition. These agents, depending on their nature, can be introduced into the fatty phase or into the aqueous phase. In the case where the emulsion is an emulsion for pharmaceutical use, it will necessarily comprise an active ingredient for the treatment or prevention of a pathology or at least one symptom associated with a pathology.

"Acceptable food agent" means any compound that has been approved as such by the national authorities of the country where the final food product comprising the emulsion will be marketed.

According to another aspect, the invention relates to a composition, called premix, consisting of: i) xanthan, ii) at least one ionic, anionic, cationic or amphoteric surfactant, and iii ) at least one lipophilic liquid.

By constituted is meant a premix containing only compounds i), ii) and iii), excluding any other type of compounds.

The premix according to the invention is a stable composition.

"Stable" premix means a composition which does not exhibit syneresis phenomena after storage for at least 24 hours, preferably 2 weeks, preferably 6 months at room temperature, preferably after storage for 12 months at room temperature. and more preferably still for 18 months at room temperature. Preferably, the xanthan present in the premix according to the invention is in concentrations ranging from 5% to 70% by weight relative to the total weight of the premix, preferably ranging from From 10% to 60% by weight, preferably ranging from 20% to 60% by weight, and more preferably ranging from 30% to 60% by weight, preferably ranging from 40% to 60% by weight, preferably ranging from 50% to 60% by weight; by weight and even more preferably xanthan is present at a concentration of 60% by weight.

Preferably, the surfactant present in the premix is in concentrations ranging from 10% to 70% by weight relative to the total weight of the premix according to the invention, preferably ranging from 10% to 60% by weight, preferentially ranging from 10% to 50% by weight, preferably ranging from 20% to 40%, more preferably from 20% to 30% by weight and even more preferably the surfactant is present at a concentration of 20% by weight.

Preferably, the lipophilic liquid present in the premix is in concentrations ranging from 10% to 80% by weight relative to the total weight of the premix according to the invention, preferably from 10% to 70% by weight, preferably from 10% to 60% by weight. % by weight, more preferably from 20% to 50% by weight, preferably ranging from 20% to 40% by weight, preferably ranging from 20% to 30% by weight and even more preferably the lipophilic oil is present at a concentration of 20% by weight.

The invention also relates to a premix consisting of: - 50 to 60% by weight of xanthan, - 20 to 30% by weight of nonionic surfactant, cationic or amphoteric, and - 20 to 30% by weight of lipophilic liquid.

The present invention also relates to a method of manufacturing a direct oil-in-water emulsion characterized in that it comprises the following steps. a) adding the premix in an aqueous phase with stirring at a temperature between 20 ° C and 20 500C; and b) maintaining agitation until a stable oil-in-water emulsion is obtained.

The present invention also relates to a method of manufacturing an oil-in-water phase-inversion emulsion characterized in that it comprises the following steps: a) adding an aqueous phase in the premix with stirring to a temperature between 20 ° C and 50 ° C; and b) maintaining agitation until a stable oil-in-water emulsion is obtained.

Preferably, the addition of the premix in the aqueous phase is carried out with stirring at a speed of between 50 and 2000 rpm, preferably between 500 and 1500 rpm.

Preferably, the stirring is maintained while stirring for a period of between 1 and 30 minutes, preferably between 5 and 20 minutes, more preferably between 5 and 15 minutes.

Such a process according to the invention makes it possible to obtain an emulsion whose quantity of surfactant and lipophilic liquid is substantially lower than those obtained by the techniques of the prior art. For example, a premix consisting of 50% of xanthan, 25% of surfactant and 25% of lipophilic liquid makes it possible to obtain, according to the process according to the invention, a stable emulsion comprising by weight relative to the total weight of the emulsion obtained, between 0.3 and 0.75% of surfactant and between 0.3 and 0.75 of lipophilic liquid.

The emulsion according to the invention According to another aspect, the invention relates to an emulsion obtained according to the methods of the invention. The emulsions of the present invention may for example be emulsions for cosmetic, food or pharmaceutical use, and preferably for cosmetic use.

Preferably, the manufacturing method according to the present invention makes it possible to obtain stable oil-water emulsions.

"Stable" emulsion means an emulsion which does not exhibit coalescence or syneresis phenomena after storage for 6 months at room temperature, preferably after storage for 12 months at room temperature, and even more preferably for 18 months. at room temperature. In the present invention, unless otherwise stated, "oil-in-water emulsion" means a stable emulsion. "Syneresis" means the process by which the liquid is released spontaneously from the gelled matrix.

By "coalescence" is meant the merging of the 5 droplets of an emulsion characterized by the formation of aggregates and which leads to the breaking of an emulsion.

Preferably, the emulsion according to the invention is characterized in that said emulsion is a cream gel with a viscosity of between 1000 and 4000 mPa.s, and preferably between 2000 and 3000 mPa.s. The emulsion according to the invention can be applied to the skin, the hairs, the eyelashes, the hair, the nails, the lips, the mucous membranes according to the use for which it is intended. In the case of an emulsion for cosmetic use, the emulsion may be used in a cosmetic skin treatment process, comprising the application of the composition according to the invention to the skin, for example with a view to toning it up. , to regenerate it, to smooth the wrinkles of the skin, and / or to fight against skin aging, against the harmful effects of UV radiation and / or to reinforce cutaneous tissues against the aggressions of the environment.

The emulsion according to the invention may be a care composition, especially a skin care product such as a skin care base, a care cream (day cream, night cream, anti-wrinkle cream), a makeup base; a care composition for the lips (lip balm); a sun protection or self-tanning composition. Said emulsion may also be a make-up composition, in particular for making up the skin, the lips, the eyelashes, the eyebrows and the hair. In particular, the makeup composition may be a foundation, a blusher, an eyeshadow, a concealer, a body makeup product. In the context of an emulsion for pharmaceutical use, the emulsion may be used in the treatment of a pathology targeted by the active ingredient it contains. For example, it may contain an antifungal agent for the treatment of mycoses.

Examples

EXAMPLE 1 Association of Gelling Agent (Xanthan, Carrageenan, Cellulose, Guar) and Cocoglucoside This example illustrates the production of emulsions according to the process of the invention in which phase A contains cocoglucoside as surfactant. Mixtures for several gelling agents are made in specified proportions.

A) Protocol of realization of the association with 7.7% of gelling agent

A) Protocol Gelling preparation (Phase A) Products% Sunflower oil 46.15 cocoglucoside 46.15 Gelling agent * 7.7 Gelifier *: xanthan, carrageenan, cellulose, guar In a beaker the oil, surface-active agent and gelling agent mixture is heated to 50 ° C. weak agitation. After obtaining a homogeneous mixture, the heating is stopped. The emulsions are produced in the following proportions: Product% Water (Phase B) 93 Gelling Preparation 6.5 (Phase A) Sepicide HB 0.5 33 The emulsion can be manufactured at a cold temperature or at 50 ° C. according to the following protocols:

Cold protocol: Phase B is placed in a beaker, phase A is added with turbine stirring (600 to 1600 rpm depending on the type and amount of gelling agent). Stirring is maintained for 10-15 minutes and the preservative is added.

Protocol at 50 ° C: Phase B is placed in a beaker and heated to 50 ° C, phase A is added heated at 50 ° C with turbine agitation (600 to 1600 rpm depending on the type and amount of gelling agent). Stirring is continued for 10-15 min and the preservative is added.

b) Experimental Results

The viscosities of the emulsions obtained according to the invention are measured using a viscometer of the Physica and Brookfield type. In the following, we note: - v (P) the viscosity measured with Physica at 20 rpm, and 25 - v (B): viscosity measured with Brookfield. The viscosity measurements are carried out at 20 rpm with mobile No. 3 unless otherwise indicated.

(i) Viscosity measurement for 0.5% xanthan: Cold protocol: Protocol at 50 ° C: v (P) = 418.9 mPa.sv (P) = 272.4 mPa.sv (B) = 1130 mPa.sv (B) = 810 mPa.s The viscosity of the emulsion obtained according to the cold protocol is higher than the viscosity of the emulsion obtained according to the Protocol at 50 ° C. These emulsions are stable at room temperature after storage for 5 months.

(ii) Viscosity measurement for 0.5% carrageenan: Cold protocol: Protocol at 50 ° C 10 v (P) = 55 mPa.sv (P) = 0 mPa.s / (B) = 25 mPa.sv (B) = 25 mPa.s

We do not obtain satisfactory viscosity for the emulsions obtained with this gelling agent. Iii) Viscosity Measurement for 0.5% Cellulose: Cold Protocol: Protocol at 50 ° C / (P) = 0 mPa.sv (P) = 0 mPa.s / (B) = 12 mPa.s * v (B) = 5 mPa.s 20 * measured at 20 rpm with mobile # 2

We do not obtain satisfactory viscosity for the emulsions obtained with this gelling agent.

Iv) Viscosity measurement for 0.5% guar gum: Cold Protocol: Protocol at 50 ° C / (P) = 216 mPa · s (P) = 205 mPa · s / (B) = 270 mPa. sv (B) = 225 mPa.s

We obtain a low viscosity with this gelling agent and the emulsions obtained is unstable. These results are therefore not satisfactory.

B) Protocol of achievement of the 14.4% gelling agent association

a) Protocol Gelling preparation (Phase A) Products% Sunflower oil 42.8 cocoglucoside 42.8 Gelling agent * 14.4 Gel *: xanthan, carrageenan, cellulose guar

The preparation protocol of phase A is identical to that described in example 1A). The emulsions are produced in the following proportions: Product% Water (Phase B) 92.5 Gelling preparation (Phase 7A) Sepicide HB 0.5 The manufacturing protocol the emulsion can be cold or at 50 ° C according to the protocols described in Example 1.A). b) Experimental results

i) Viscosity measurement for 1% xanthan: Cold protocol: Protocol at 50 ° C: 20 v (P) = 932 mPa.sv (P) = 785 mPa.sv (B) = 3320 mPa.sv (B) ) = 3005 mPa.s15 The viscosity of the emulsion obtained according to the cold protocol is higher than the viscosity of the emulsion obtained according to the Protocol at 50 ° C. The emulsions obtained are stable at ambient temperature after storage for 5 months and show no syneresis phenomenon.

(ii) Viscosity measurement for carrageenan

10 Cold Protocol: Protocol at 50 ° C / (P) = 403 mPa · s (P) = 225 mPa · s / (B) = 795 mPa · s · v (B) = 275 mPa · s

The viscosity of the emulsion obtained according to the cold protocol is higher than the viscosity of the emulsion obtained according to the Protocol at 50 ° C. The emulsions are not very stable and have a beginning of syneresis.

Iii) Viscosity Measurement for 1% Cellulose: Cold Protocol: Protocol at 50 ° C / (P) = 0 mPa.sv (P) = 0 mPa.s / (B) = 70 mPa.sv (B) ) = 10 mPa.s

We do not obtain satisfactory viscosity for the emulsions obtained with this gelling agent.

(iv) Viscosity measurement for 1% guar gum: Cold protocol: Protocol at 50 ° C 30 v (P) = 1000 mPa.sv (P) = 860 mPa.s / (B) = 2800 mPa.sv ( B) = 2000 mPa.s 38

The viscosity of the emulsion obtained according to the cold protocol is higher than the viscosity of the emulsion obtained according to the Protocol at 50 ° C. The emulsions are unstable and exhibit a beginning of syneresis.

C) Protocol of realization of the association with 22% of gelling agent

A) Protocol Gelling preparation (Phase A) Products% Sunflower oil 39 cocoglucoside 39 Gelling agent * 22 Gelant *: xanthan, carrageenan, cellulose, guar

The preparation protocol of phase A is identical to that described in example 1.A). The emulsions are produced in the following proportions: Product% Water (Phase B) 93 Gelling Preparation 7.5 (Phase A) Sepicide HB 0.5 The emulsion production protocol can be performed at a cold temperature or at 50 ° C. according to the protocols described in Example 20 lA)

b) Experimental Results i) Viscosity Measurement for 1.5% xanthan: Cold Protocol: Protocol at 50 ° C / (P) = 1354 mPa.sv (P) = 1320 mPa · s / (B) = 5670 mPa .s * v (B) = 5470 mPa.s * * measured at 20 rpm with mobile No. 2 The viscosity of the emulsion obtained according to the cold protocol is the same as that obtained according to the protocol at 50 ° C. . The emulsions obtained are stable at room temperature after storage for 5 months and show no syneresis phenomenon.

(ii) Viscosity measurement for 1.5% carrageenan: Cold Protocol: Protocol at 50 ° C / (P) = 703 mPa · s (P) = 776 mPa · s / (B) = 1825 mPa · s (B) = 2520 mPa.s

The viscosity of the emulsion obtained according to the cold protocol is the same as that obtained according to the protocol at 50 ° C. The emulsions obtained are heterogeneous.

iii) Viscosity measurement for cellulose at 1.5%: Cold protocol: Protocol at 50 ° C 25 v (P) = 0 mPa.sv (P) = 0 mPa.s / (B) = 90 mPa.sv (B) ) = 5 mPa.s

We do not obtain satisfactory viscosity for the emulsions obtained with this gelling agent. (iv) Viscosity measurement for 1.5% guar gum: Cold protocol: Protocol at 50 ° C 30 / (P) = 2658 mPa.sv (P) = 2529 mPa.s / (B) = 8800 mPa.s * v (B) = 8830 mPa.s * * measured at 20 rpm with mobile No. 4 The viscosity of the emulsion obtained according to the cold protocol is the same as that obtained according to the protocol at 50 ° C. The emulsions exhibit a syneresis phenomenon after one week of storage at room temperature. EXAMPLE 2 Association of gelling agent (xanthan, carrageenan, cellulose, guar) and laurylglucoside

This example illustrates the production of emulsions according to the process of the invention in which phase A contains laurylglucoside as surfactant. The mixtures for several gelling agents are carried out in specified proportions:

A) Protocol for Making the 7.7% Gelling Association

a) Protocol Gelling Preparation (Phase A) Products% Sunflower oil 46.15 laurylglucoside 46.15 Gelling agent * 7.7 Gelifier *: xanthan, carrageenan, cellulose guar The preparation protocol of phase A is identical to that described in example l.A). The emulsions are produced in the following proportions: Product% Water (Phase B) 93 Gelling Preparation 6.5 (Phase A) Sepicide HB 0.5 The emulsion production protocol can be carried out at a cold temperature or at 50 ° C. according to the protocols described. in example 1A).

b) Experimental results

(i) Viscosity measurement for 0.5% xanthan: 10 Cold Protocol: Protocol at 50 ° C: / (P) = 426 mPa · s (B) = 1085 mPa · s / (B) = 1425 mPa. sv (B) = 1085 mPa.s

The viscosity of the emulsion obtained according to the cold protocol is higher than the viscosity of the emulsion obtained according to the protocol at 50 ° C. The emulsions obtained are stable after storage for 5 months at room temperature and show no syneresis phenomenon. Ii) Measurement of Viscosities for 0.5% Carrageenan: Cold Protocol: Protocol at 50 ° C: / (P) = 0 mPa.sv (P) = 0 mPa.s 25 v (B) = 30 mPa .sv (B) = 25 mPa.s

We do not obtain satisfactory viscosity for the emulsions obtained with this gelling agent.

(iii) Viscosity measurement for 0.5% cellulose: Cold protocol: Protocol at 50 ° C: v (P) = 0 mPa.sv (P) = 0 mPa.sv (B) = 5 mPa.sv ( B) = 0 mPa.s

We do not obtain satisfactory viscosity for the emulsions obtained with this gelling agent. iv) Viscosity measurement for 0.5% guar gum: Cold protocol: Protocol at 50 ° C: v (P) = 297 mPa.sv (P) = 270 mPa.sv (B) = 405 mPa.sv (B) = 295 mPa.s

The emulsions obtained have a low viscosity with this gelling agent and exhibit a syneresis phenomenon.

B) Protocol of achievement of the 14.4% gelling agent association

a) Protocol Gelling Preparation (Phase A) Products% Sunflower oil 42.8 laurylglucoside 42.8 Gelling agent * 14.4 Gelifier *: xanthan, carrageenan, cellulose guar The preparation protocol of phase A is identical to that described in example 1. A). The emulsions are produced in the following proportions: Product% Water (Phase B) 92.5 Gelling Preparation 7 (Phase A) Sepicide HB 0.5 The emulsion manufacturing protocol can be carried out at 5 ° C. or at 50 ° C. according to the protocols described in Example 1A).

b) Experimental results

I) Viscosity measurement for 1% xanthan: Cold protocol: Protocol at 50 ° C: / (P) = 1024 mPa.sv (P) = 810 mPa.s / (B) = 3960 mPa.sv ( B) = 3050 mPa.s

The viscosity of the emulsion obtained according to the cold protocol is higher than the viscosity of the emulsion obtained according to the protocol at 50 ° C. The emulsions do not exhibit syneresis phenomena.

Ii) Measurement of viscosities for carrageenan at 1 °. ° Cold protocol: Protocol at 50 ° C: / (P) = 230 mPa.sv (P) = 246 mPa.s / (B) = 330 mPa.sv (B) = 350 mPa.s. The viscosity of the emulsions obtained are weak. The results obtained are therefore not satisfactory. (iii) Viscosity measurement for 1% cellulose: Cold protocol: Protocol at 50 ° C: / (P) = 0 mPa.sv (P) = 0 mPa.s / (B) = 5 mPa.sv (B) ) = 15 mPa.s We do not obtain satisfactory viscosity for the emulsions obtained with this gelling agent.

iv) Viscosity Measurement for 1% Guar Gum: 10 Cold Protocol: 50 ° C Protocol: / (P) = 1079 mPa · s (P) = 971mPa. s / (B) = 2890 mPa.s (B) = 2655 mPa.s

The viscosity of the emulsion obtained according to the cold protocol is the same as that obtained according to the protocol at 50 ° C. The emulsions obtained are unstable.

C) Protocol for making the 22% gelling agent combination a) Protocol Gelling preparation (Phase A) Products% Sunflower oil 39 laurylglucoside 39 Gelling agent * 22 Gelant *: xanthan, carrageenan, cellulose guar

The preparation protocol of phase A is identical to that described in example 1.A). The emulsions are produced in the following proportions: Product% Water (Phase B) 92 Gelling Preparation 7.5 (Phase A) Sepicidal HB 0.5 The emulsion production protocol can be carried out at a cold temperature or at 50 ° C. according to the protocols described. in example 1.A). b) Experimental results

i) Viscosity measurement for 1.5% xanthan: Cold protocol: Protocol at 50 ° C: 10 v (P) = 1473 mPa.sv (P) = 1274 mPa.s / (B) = 6520 mPa.sv ( B) = 4775 mPa.s

The viscosity of the emulsion obtained according to the cold protocol is the same as that obtained according to the protocol at 50 ° C. The emulsion obtained according to the cold protocol is stable after 5 months of storage at room temperature and shows no syneresis phenomenon.

Ii) Viscosity Measurement for O Carrageenan. Cold Protocol: Protocol at 50 ° C: / (P) = 747 mPa · s (P) = 768 mPa · s / (B) = 1695 mPa · s (B) ) = 2780 mPa.s. The viscosity of the emulsion obtained according to the cold protocol is the same as that obtained according to the protocol at 50 ° C. The emulsions obtained are heterogeneous, which is unsatisfactory for an emulsion.

(iii) Viscosity measurement for 1.5% cellulose: Cold protocol: Protocol at 50 ° C: / (P) = 53 mPa.sv (P) = 0 mPa.s / (B) = 75 mPa.sv (P) ) = 0 mPa.s

We do not obtain a satisfactory viscosity for the emulsions obtained according to the process at 50 ° C. with this gelling agent.

iii) Viscosity measurement for guar gum at 1.5%. Cold Protocol: Protocol at 50 ° C: / (P) = 2691 mPa · s v (P) = 2476 mPa · s / (B) = 9940 mPa · s · v (B) = 9040 mPa · s

The viscosity of the emulsion obtained according to the cold protocol is the same as that obtained according to the protocol at 50 ° C. The emulsions obtained rapidly exhibit a syneresis phenomenon.

Example 3: Association of gelling agent (xanthan, carrageenan, guar) and plurol diisostearic acid

This example illustrates the production of emulsions according to the process of the invention in which phase A contains, as surface-active agent, diisostearic plurol (INCI Polyglyceryl-3 Diisostearate).

A) Protocol for making the 7.7% gelling agent combination a) Protocol Gelling preparation (Phase A) Products% Sunflower oil 46.15 Diisostearic plurol 46.15 Gelling agent * 7.7 Gelant *: xanthan, carrageenan, guar

The preparation protocol of phase A is identical to that described in example l.A).

The emulsions are produced in the following proportions: Product% Water (Phase B) 93 Gelling Preparation 6.5 (Phase A) Sepicidal HB 0.5 The emulsion production protocol may be performed at a cold temperature or at 50 ° C. according to the protocols described in US Pat. Example 1A).

b) Experimental results

(i) Viscosity measurement for 0.5o xanthan: Cold protocol: Protocol at 50 ° C: 20 v (P) = 398 mPa.sv (P) = 262 mPa.sv (B) = 1285 mPa.sv ( B) = 770 mPa.s. The viscosity of the emulsion obtained according to the cold protocol is higher than the viscosity of the emulsion obtained according to the protocol at 50 ° C. The resulting emulsions are stable after 5 months of storage at room temperature.

(ii) Viscosity measurement for 0.5% carrageenan: Cold protocol: Protocol at 50 ° C: 10 v (P) = 0 mPa.sv (P) = 55 mPa.sv (B) = 35 mPa.sv (B) = 40 mPa.s

We do not obtain satisfactory viscosity for the emulsions obtained with this gelling agent. Iii) Viscosity Measurement for 0.5% Guar Gum: Cold Protocol: Protocol at 50 ° C: v (P) = 286 mPa · s (P) = 286 mPa · 20 v (B) = 550 mPa.sv (B) = 460 mPa.s

The emulsions obtained have a low viscosity with this gelling agent. These emulsions have, in addition, a beginning of syneresis. B) Protocol of achievement of the 14.4% gelling agent association

a) Protocol 25 Gelling preparation (Phase A) Products% Sunflower oil 42.8 Plurol diisostearic 42.8 gelling agent 14.4 Gel *: xanthan, carrageenan, guar

The preparation protocol of phase A is identical to that described in example 1.A). The emulsions are produced in the following proportions: Product% Water (Phase B) 92.5 Gelling preparation 7 (Phase A) Sepicidal HB 0.5 The emulsion manufacturing protocol can be carried out at a cold temperature or at 50 ° C. according to the protocols described in Example 1A).

b) Experimental results

(i) Viscosity measurement for 1% xanthan. Cold Protocol: Protocol at 50 ° C: v (P) = 1024 mPa · s (P) = 810 mPa · s (B) = 3960 mPa · s (B) = 3050 mPa.s

The viscosity of the emulsion obtained according to the cold protocol is higher than the viscosity of the emulsion obtained according to the Protocol at 50 ° C. The emulsions obtained are stable after storage for 5 months at room temperature and show no syneresis phenomenon. Ii) Measurement of viscosities for 1% carrageenan: Cold protocol: Protocol at 50 ° C: / (P) = 230 mPa.s * 5 v (B) = 330 mPa.s * measured at 50 rpm

The viscosities of the emulsions obtained are low and are therefore not satisfactory.

(iii) Viscosity measurement for 1% guar gum: Cold protocol: Protocol at 50 ° C: / (P) = 1264 mPa.sv (P) = 1026 mPa.s / (B) = 6260 mPa.sv ( B) = 3215 mPa.s

The viscosity of the emulsion obtained according to the cold protocol is the same as that obtained according to the protocol at 50 ° C. The emulsions obtained exhibit a syneresis phenomenon.

C) Protocol of realization of the association with 22% of gelling agent

a) Protocol Gelling preparation (Phase A) Products% Sunflower oil 39 Plurol diisostearic 39 Gelling agent * 22 25 Gelant *: xanthan, carrageenan, guar

The preparation protocol of phase A is identical to that described in example 1.A). v (P) = 246 mPa.sv (B) = 350 mPa.s. The emulsions are produced in the following proportions: Product% Water (Phase B) 92 Gelling Preparation 7.5 (Phase A) Sepicidal HB 0.5 manufacture of the emulsion can be done cold or at 50 ° C according to the protocols described in Example 1A).

b) Experimental results i) Viscosity measurement for 1.5% xanthan: Cold protocol: Protocol at 50 ° C: / (P) = 1182 mPa.sv (P) = 998 mPa.s / (B) = 5040 mPa (B) = 3695 mPa.s. The viscosity of the emulsion obtained according to the cold protocol is the same as that obtained according to the protocol at 50 ° C. The emulsion is stable after 5 months storage at room temperature and shows no syneresis phenomenon.

ii) Viscosity measurement for 1.5% carrageenan: Cold Protocol: Protocol at 50 ° C: / (P) = 85 mPa · s (P) = 145 mPa · s / (B) = 75 mPa. sv (B) = 75 mPa.s. The viscosities of the emulsions obtained are very low and are therefore not satisfactory.

iii) Viscosity measurement for guar gum at 1.5%: Cold protocol: Protocol at 50 ° C: v (P) = 2274 mPa.sv (P) = 1752 mPa.sv (B) = 10300 mPa.sv ( B) = 4940 mPa.s

The viscosity of the emulsion obtained according to the cold protocol is higher than the viscosity of the emulsion obtained according to the Protocol at 50 ° C. The emulsions obtained exhibit a syneresis phenomenon. EXAMPLE 4 Association of Xanthan and Sodium Laureth Sulfate

This example illustrates obtaining an emulsion according to the process of the invention wherein phase A contains sodium laureth sulfate.

a) Cold Protocol The 14.4% xanthan combination is carried out with an anionic surfactant marketed by Cognis under the Texapon NSO name. In a beaker the oil, Texapon NSO and xanthan are mixed cold with low stirring and in the proportions specified in the table below: Gelling preparation (Phase A) Products% Sunflower oil 42.B Texapon NSO 42.8 xanthan 14.4 The emulsions are then produced in the following proportions: Product% Water (Phase B) 92.5 Gelling Preparation 7 (Phase A) Sepicidal HB 0.5 The water is weighed and then the gelling preparation is mixed with stirring at 500 to 1400 rpm. Stirring is continued for 15 minutes and Sepicide HB is added.

b) Experimental result

The viscosity of the emulsion obtained is measured and a viscosity of 3965 mPa.s is obtained using a Brookfield viscometer (20 rpm, mobile No. 3).

The emulsion obtained is stable and shows no syneresis phenomenon. EXAMPLE 5 Association of Xanthan and Sodium Lauroyl Glutamate

This example illustrates obtaining an emulsion according to the process of the invention wherein phase A contains sodium lauroyl glutamate.

a) Cold protocol

The 14.4% xanthan combination is carried out with an anionic surfactant marketed by Zschimmer and Schwartz under the name Protelan AGL 95 (INCI: Sodium Lauroyl Glutamate).

In a beaker, the oil, Protelan AGL 95 and xanthan are mixed cold with low stirring and in the proportions specified in the table below: Gelling preparation (Phase A) Products% Sunflower oil 42.8 Protelan AGL 95 42.8 xanthane 14.4 In a beaker the oil, Protelan AGL 95 and xanthan are mixed cold with gentle stirring.

The emulsions are then produced in the following proportions: Product% Water (Phase B) 92.5 Gelling Preparation 7 (Phase A) Sepicidal HB 0.5 The water is weighed and then the gelling preparation is incorporated with stirring at 500 to 1400 rpm. Stirring was continued for 15 minutes and Sepicide HB was added.

b) Experimental result

The viscosity of the emulsion obtained is measured and a viscosity of 4210 mPa.s is obtained using a Brookfield type viscometer (20 rpm, mobile No. 3).

The emulsion obtained is stable and exhibits no syneresis phenomenon. Example 6 Obtaining the emulsion according to the process of the invention by indirect route

This example illustrates the production of an emulsion according to the process of the invention in which phase A contains diisostearic plurol.

a) Protocol

The 14.4% xanthan combination was performed with diisostearic plurol.

In a beaker, the oil, the plurol diisostearic acid and the xanthan with low stirring are cold-mixed and in the proportions specified in the table below: Gelling preparation (Phase A) Products% Sunflower oil 42.8 Plurol diisostearic 42.8 xanthan 14.4 In a beaker the oil, the plurol diisostearic acid and the xanthan are mixed cold with low stirring. The emulsions are then produced in the following proportions: Product% Water (Phase B) 92.5 Gelling Preparation 7 (Phase A) Sepicidal HB 0.5 The water is added to the gelling preparation and the mixture is stirred at the beginning with the aid of a spatula to loosen the mixture from the bottom of the beaker. Then the beaker is placed under mechanical stirring (1300 rpm). Stirring is maintained for 15 minutes. B) Experimental results

The viscosity of the emulsion obtained is measured and a viscosity of 3190 mPa.s is obtained using a Brookfield viscometer (20 rpm, mobile No. 3).

The emulsion obtained is stable and exhibits no syneresis phenomenon.

EXAMPLE 7 Reproducibility of the Process According to the Invention This example illustrates the production of stable emulsions from xanthan marketed by different suppliers.

a) Protocol Emulsions are produced in the following proportions: ## EQU1 ## 1) Keltrol 1% C 1% C 1% C 1% C 1% C 1% C Stiaxane CX911 1% Plurol oil Water 0.50% sterile diisostearic sunflower E Saltiaxane CX931 1% 3% 3% 93% F Rhodicare T 1% G Keltrol 1% H Satiaxane CV930 1% The suppliers of xanthans used in the context of this example are detailed in the table. below: Products Suppliers Keltrol CG-SFT CP kelco Rhodicare Rhodia Keltrol T CP Kelco Satiaxane CX911 Cargill (Laserson) Satiaxane CX931 Cargill (Laserson) Rhodicare CFT Rhodia Rhodicare T Rhodia Satiaxane CX930 Cargill (Laserson) In a dish, we mix xanthan , oil and surfactant.

In a beaker, the previously obtained mixture is poured into water with stirring of 1500 rpm. Stirring is maintained for a period of 10 to 30 minutes, then the preservative is added and mixed.

b) Measurements At constant temperature and pressure, for each of the emulsions obtained as above, the values of: the viscosity r (in Pa) are measured; > the shear rate (in s-1); - the shear stress Uen Pa).

The curves n = f (t) representing the dynamic viscosities of each of the emulsions are plotted as a function of the shear rate. At the same time, we plot the curves = f (ÿ) representing the shear stresses as a function of the shear rate.

C) Results The curves are superimposed, which indicates the absence of a significant difference between the viscosity of each of the emulsions obtained and the shear force of each of the emulsions. Therefore, the process according to the invention makes it possible to obtain emulsions having the same rheological behavior, regardless of the nature of the xanthan used and its commercial origin.

The inventors have thus demonstrated here that the process according to the invention is reproducible.

Example 8: Use of stable premix for obtaining emulsion.

10 A) Obtaining premixes

a) Protocol The inventors made the following mixtures (premix). Xanthan Premix (%) Oil (%) Surfactant (%) 1 22.8 37.2 40 2 7 73 20 3 20 20 60 4 7 33 60 30 20 50 6 7 33 60 7 40 30 30 8 The xanthan, the oil and the surfactant used are Keltrol, respectively. CG-SFF, sunflower oil, and diisostearic Plurol.

The mixtures of the three components of each of the premixes are obtained using the Turrax Dispenser at 8000 min-1.

b) Result The obtained premixes are stable. The premix 15 is stable for 40 days at room temperature.

B) Obtaining emulsions from the premixes

a) Protocol The inventors made the emulsions (called I, J, K, and L) according to the process of the invention, using the previously obtained premixes 15 and 16. The composition of the emulsions produced is detailed in the table below: Emulsion Keltrol Amount Plurol oil water Preservative CD-SFT sunflower premix I 1.5% 3 g 0.75% 0.75% 96.50% 0.50 % J 1% 2 g 0.5% 0.5% 97.50% 0.50% K 1.5% 2.5 g 0.335% 0.5% 97.83% 0.50% L 1% 1, 67 g 0.335% 0.335% 97.83% 0.50% The emulsions I and J are obtained from the premix 16 and the emulsions K and L are obtained from the premix 15. For each of the emulsions, the amount of premix as defined in the table above. With stirring at 1500 rpm for 30 minutes, the premix is mixed in water. Then, add the preservative and mix.

b) Measurements At constant temperature and pressure, the values of viscosity n, shear rate, and shear stress are measured for each of the emulsions obtained as above. The curves n = f () and = f (ÿ) for each emulsion obtained.

c) Results i) Stability: Emulsions I to L are stable at centrifugation. Emulsion L is stable for 2 weeks at 50 ° C.

ii) Rheological behavior: The curves n = f () and = f ();) are superimposed. There is therefore no significant difference between, on the one hand, the viscosity of each of the emulsions obtained and, on the other hand, the shearing force of each of the emulsions.

Example 9 Use of the premix according to the invention for the production of indirect emulsion.

This example illustrates obtaining emulsion from the premix obtained in Example 8a) and by the reverse route.

The constituents of such an emulsion and their proportions are detailed in the table below: Phase Ingredients Amount (%) A Primer 1.67 Vaseline oil 5 B QSP water The components of phase A are mixed in a container. The aqueous phase B is then poured into phase A with stirring at 1500 rpm. Stirring is continued for about 5 to 15 minutes.

The premix according to the invention thus makes it possible to obtain an emulsion by the direct route and by phase inversion.

EXAMPLE 10 Preparation of a Cleansing Milk from the Premix According to the Invention

a) Protocol 100 g of cleansing milk are prepared from the premix 15 obtained in Example 8a). The constituents of such a cleansing milk and their proportions are detailed in the table below: Phase Ingredients Quantity per 100g A Premix 1.67 Sweet almond oil 3 Water Qsp = 76.53 B Dermofeel PA-3 0.1 Glycerin 5 Protelan Ag 818G 2.5 C Water 5 Allantoin 0.2 D Ethanol 5 Koko ML 0.2 E Geogard 221 0.5 F Perfume QS 63

The components of phase A are mixed in a container. In another container, the constituents of phase B are mixed. Phase B is then stirred at a speed of 700 rpm. Phase A is added to phase B. The stirring speed is increased to 1500 rpm. Then, the phases C, D and E are successively added. Stirring is maintained for about 10 minutes before adding the perfume. b) Result A stable emulsion is obtained 2 weeks at room temperature and 9 days at 50 ° C. The emulsions obtained show no syneresis phenomenon.

Claims (10)

Revendications1. A method of manufacturing an oil-in-water emulsion by a direct route, characterized in that it comprises the following steps: a) preparation of a phase A, comprising the following elements: xanthan, at least one nonionic, anionic, cationic or amphoteric surfactant; and - at least one lipophilic liquid; b) stirring phase A to homogenization, preferably at a stirring speed of between 5 and 250 rpm and more preferably at a stirring speed of less than 50 rpm; c) preparing an aqueous phase B, preferably at a temperature between 20 and 50 ° C; D) addition of phase A to phase B with stirring at a temperature between 20 ° C and 50 ° C for a period of between 5 and 30 minutes, preferably between 5 and 20 minutes, more preferably between 5 and 10 minutes and even more preferably for a period of 10 minutes; and e) maintaining stirring until a stable oil-in-water emulsion is obtained. 2. A method for manufacturing an oil-in-water emulsion by phase inversion, characterized in that it comprises the following steps: a) preparation of a phase A, comprising the following elements:> xanthan, - at minus a surfactant of nonionic, anionic, cationic or amphoteric type; at least one lipophilic liquid; b) stirring of phase A until homogenization, preferably at a stirring speed of between 5 and 250 rpm and more preferably at a stirring speed of less than 50 rpm; c) preparing an aqueous phase B, preferably at a temperature between 20 and 50 ° C; d) adding phase B to phase A with stirring at a temperature of between 20 ° C. and 50 ° C. for a period of between 5 and 30 minutes, preferably between 5 and 20 minutes, more preferably between 5 and 10 minutes, and even more preferably for a period of 10 minutes; and e) maintaining stirring until a stable oil-in-water emulsion is obtained. 3. Method according to any one of claims 1 to 2, characterized in that the xanthan used in phase A is in concentrations ranging from 0.01% to 5% by weight relative to the total weight of the emulsion. obtained according to said process, preferably ranging from 0.1% to 5% by weight, and more preferably from 0.5% to 1.5% by weight. 15 4. Method according to any one of claims 1 to 3, characterized in that the surfactant used in phase A is in concentrations ranging from 0.01% to 10% by weight relative to the total weight of the product. emulsion obtained according to said process, preferably from 0.1% to 5% by weight, preferably from 1% to 3% by weight, preferably between 1% and 2% by weight, and more preferably between 0.3 and 0.75% by weight. % in weight. 5. Composition consisting of: i) xanthan, ii) at least one ionic, anionic, cationic or amphoteric surfactant, and iii) at least one lipophilic liquid. 6. Composition according to claim 5, characterized in that the xanthan is present in concentrations ranging from 5% to 70% by weight relative to the total weight of the premix, preferably ranging from 10% to 60% by weight, preferably ranging from 20% to 60% by weight, and more preferably ranging from 30% to 60% by weight, preferably ranging from 40% to 60% by weight, preferably ranging from 50% to 60% by weight and even more preferably xanthan is present at a concentration of 60% by weight. 7. Composition according to claim 5 or 6, characterized in that the surfactant is present in concentrations ranging from 10% to 70% by weight relative to the total weight of the premix according to the invention, preferably ranging from 10%. at 60% by weight, preferably ranging from 10% to 50% by weight, preferably ranging from 20% to 40%, more preferably ranging from 20% to 30% by weight and even more preferentially the surfactant is present at a concentration of 20% by weight. 8. Composition according to any one of claims 5 to 7, characterized in that the lipophilic liquid is present in concentrations ranging from 10% to 80% by weight relative to the total weight of the premix according to the invention, preferably from 10 to 10% by weight. % to 70% by weight, preferably from 10% to 60% by weight, more preferably from 20% to 50% by weight, preferably ranging from 20% to 40% by weight, preferably ranging from 20% to 30% by weight and more preferably, the lipophilic oil is present at a concentration of 20% by weight. 9. A process for producing an oil-in-water emulsion by direct route, characterized in that it comprises the following steps: a) adding the composition according to any one of claims 5 to 8 in an aqueous phase under stirring at a temperature between 20 ° C and 50 ° C; and b) maintaining agitation until a stable oil-in-water emulsion is obtained. 10. A process for manufacturing an oil-in-water emulsion by phase inversion, characterized in that it comprises the following steps: a) adding an aqueous phase to the composition according to any one of claims 5 to 8; with stirring at a temperature between 20 ° C and 50 ° C; and b) maintaining agitation until a stable oil-in-water emulsion is obtained.