FR3150815A1 - EMULSIFYING AGENT FOR THE PREPARATION OF TOPICAL COMPOSITIONS - Google Patents

Abstract

The subject of the invention is an emulsifying agent characterized in that it comprises from 5% to 30% by weight of phospholipids enriched in lysophosphatidylcholine (LPC) in a suitable vehicle. The subject of the invention is also the use of this emulsifying agent in the preparation of topical compositions, in particular cosmetic compositions, and said compositions as such.

Description

EMULSIFYING AGENT FOR THE PREPARATION OF TOPICAL COMPOSITIONS

The present invention relates to the field of emulsifying agents for the preparation of topical compositions, in particular for cosmetic purposes.

TECHNOLOGICAL BACKGROUND

Stable colloidal dispersions or emulsions are present in many cosmetic products intended to be applied to the skin or one of its appendages.

Oil-in-water emulsions are thermodynamically sound systems consisting of oil droplets dispersed in an aqueous medium. These systems are unstable and tend to decompose due to complex physicochemical mechanisms, such as flocculation, coalescence, and sedimentation. To produce stable emulsions, it is necessary to incorporate stabilizers such as emulsifying, thickening, or gelling agents.

To date, the most commonly used emulsifiers in cosmetic products are surfactants or emulsifiers from the petrochemical industry. These surfactants include cationic surfactants such as Polyquaternium-10 and anionic surfactants such as sodium dodecyl sulfate (SDS) and linear alkylbenzene sulfonates as well as nonionic surfactants such as fatty alcohol ethers and grafted acrylic acid polymers.

The use of such surfactants poses environmental problems both because of their synthesis process and their fate in the environment. Indeed, these surfactants are difficult to eliminate by conventional wastewater treatments and can therefore end up in agricultural soils and the aquatic ecosystem.

On the other hand, there is a growing demand for natural cosmetic products and/or those with a reduced ecological impact. To date, there are a limited number of surfactants that meet the COSMOS® certification.

Therefore, there is a need for alternatives to traditional surfactants from the petrochemical industry.

FIGURES

shows the optical microscopy image of the emulsion obtained with soy lecithin in Example 2 d).

shows the optical microscopy image of the emulsion obtained with the emulsifying agent according to the invention in Example 2 d).

The invention relates to an emulsifying agent characterized in that it comprises from 5% to 30% by weight of phospholipids enriched in lysophosphatidylcholine (LPC) and from 70% to 95% by weight of a solvent chosen from the group consisting of glycerin, C ₂ -C ₅ alkanediols, mixtures thereof as well as aqueous mixtures thereof.

In certain embodiments, the emulsifying agent is characterized in that its phospholipid composition is such that:

- the LPCs represent at least 60% by weight, preferably at least 75% by weight of the total weight of said phospholipids, and

- phosphatidylcholine (PC) represents at most 5%, preferably at most 2.5% by weight of the total weight of said phospholipids.

In other embodiments, the emulsifying agent is characterized in that its phospholipid composition is such that:

- 1-lysophosphatidylcholine (1-LPC) represents at least 3% by weight, preferably from 8% to 13% by weight of the total weight of said phospholipids

- 2-lysophosphatidylcholine (2-LPC) represents at least 75% by weight, preferably from 75% to 90% by weight of the total weight of said phospholipids.

In some embodiments, the emulsifying agent is characterized in that it optionally comprises an antioxidant agent, preferably tocopherol.

In additional embodiments, the emulsifying agent as defined above is characterized in that it comprises from 10% to 25% by weight of LPC, preferably from 12% to 18% by weight of LPC.

According to an additional aspect, the invention relates to a topical composition, preferably cosmetic, characterized in that it comprises the emulsifying agent as defined herein, preferably in a content of at most 10% by weight.

Said topical composition is typically chosen from a cosmetic care product, a hygiene product, a perfume and a makeup product, preferably from a cream, a cream gel, a milk, a makeup remover, a micellar water, in particular a makeup remover, a mask, a shampoo, a conditioner, a shower gel, a lipstick, a foundation, a tinted cream (e.g. a BB cream), a mascara, an eye shadow, an eyeliner, a serum, a spray or a lotion, in particular a sunscreen, a perfumed water or mist and an aqueous perfume.

In a particular embodiment, the cosmetic composition is a translucent or transparent oil-in-water emulsion. It may in particular be a perfumed water or a transparent perfumed mist. Said cosmetic composition may comprise or consist essentially of

- from 0.1% to 5.0%, preferably from 0.5% to 2.0% of an oily phase comprising odorous molecules,

- from 0.1% to 5.0%, preferably from 0.5% to 2.0% by weight of the emulsifying agent according to the invention,

- optionally up to 5.0% by weight of preservative,

in the water.

In another embodiment, the topical composition is a micellar water or transparent serum for topical application characterized in that it comprises the emulsifying agent according to the invention in a content of at most 5% by weight in the water.

In a further embodiment, the aqueous perfume composition comprises:

- at most 5% by weight of the emulsifying agent as defined above,

-at most 10% by weight of odorous molecules, preferably from 0.1% to 5.0% by weight,

- at most 50% by weight of ethanol, preferably from 10% to 45% by weight of ethanol

in the water,

the percentages being expressed by weight relative to the total weight of the composition.

The invention also relates to the use of the emulsifying agent according to the invention for:

- the preparation of an oil-in-water emulsion or a translucent micellar water, preferably transparent,

- the stabilization of topical compositions in the form of emulsion and the improvement of organoleptic properties, in particular to provide a soft and non-greasy feel,

- the preparation of perfume with reduced ethanol content,

- stabilization of the dispersion of lipophilic odorous molecules in water, and/or

- increasing the penetration and diffusion of a lipophilic active agent in the skin.

According to an additional aspect, the invention relates to a process for preparing the emulsifying agent as defined herein comprising the following steps:

(a) the provision of phospholipids comprising at least 60% by weight of LPC,

(b) adding a vehicle preferably chosen from C ₂ -C ₅ alkanediols, glycerin, mixtures thereof and their aqueous mixtures, so as to obtain a dispersion,

said method possibly comprising a step of pre-solubilization of the phospholipids in an alcohol or a hydroalcoholic mixture before dispersion in the vehicle and elimination of the alcohol, once the dispersion has been obtained.

DETAILED DESCRIPTION OF THE INVENTION

Lecithins are functional ingredients used in the cosmetic field as a vectorizing agent for active ingredients or as emulsifiers. Their use as an emulsifying agent remains limited due to their poor performance: emulsions obtained with lecithins have low stability, non-uniform drop sizes and a tendency to cream, requiring the use of thickeners or gelling agents.

The Applicant sought to develop a new emulsifying agent of natural origin with improved properties. The Applicant thus showed that it was possible to prepare an improved emulsifying agent from lysophosphatidylcholines (LPCs). LPCs are generally considered to be degradation products of lecithins, the presence of which should be avoided. In the isolated state, LPCs are in the form of a very hard and poorly soluble wax, which is difficult to handle.

Surprisingly, the Applicant has shown that it is possible to solubilize a phospholipid composition highly enriched in LPC in glycerin. The Applicant has also shown that the cosmetic ingredient thus obtained is a powerful emulsifier that does not have the disadvantages of lecithins: the emulsifying agent according to the invention makes it possible to obtain fine and homogeneous emulsions, stable over time, and not presenting any creaming problem during their preparation. The emulsions also have improved organoleptic properties, namely a silky, soft and much less greasy feel than the emulsions obtained with a conventional lecithin. The emulsifying agent according to the invention can be used without thickener or gelling agent, and allows the preparation of fluid, stable and sprayable formulas.

The emulsifying agent according to the invention has other advantages in comparison with conventional lecithins.

Indeed, lecithins form opalescent or milky, or even whitish, suspensions in water. Surprisingly, the emulsifying agent according to the invention forms fine micelles in water capable of solubilizing significant quantities of oily phase such as perfumes and liposoluble active ingredients while maintaining a translucent or even transparent appearance. The emulsifying agent according to the invention can therefore be used to prepare transparent cosmetic compositions, for example micellar waters or perfumed waters or serums, without using synthetic solubilizing agents such as polysorbates.

- Emulsifying agent according to the invention

According to a first aspect, the invention relates to an emulsifying agent based on lysophosphatidylcholines (LPC). Typically, the LPCs are the majority phospholipids present in the emulsifying agent: The LPCs represent at least 60% by weight of the total weight of the phospholipids present in the emulsifying agent. In other words, the emulsifying agent is prepared from phospholipids enriched in LPC. It can also be considered that the emulsifying agent comprises an LPC having a mass purity of at least 60%.

For the purposes of the invention, the term “phospholipids” means molecules comprising a hydrophilic head comprising a phosphate group linked to a glycerol residue comprising one or two fatty chains. A phospholipid comprising a single fatty chain corresponds to a lysophospholipid. For the purposes of the invention, the term “phospholipid” therefore refers both to phospholipids comprising a single fatty chain such as LPC but also to phospholipids comprising two fatty chains such as PC.

The emulsifying agent according to the invention comprises at least 5%, preferably at least 10% by weight of phospholipids in a suitable vehicle. The suitable vehicle represents at least 65%, preferably at least 70% by weight of the total weight of the emulsifying agent.

In some embodiments, the emulsifying agent comprises from 5% to 30% by weight of phospholipids and from 70% to 95% by weight of the vehicle, these percentages referring to the total weight of the emulsifying agent.

The vehicle is typically selected from glycerin, C ₂ -C ₅ alkanediols such as 1,2-propanediol, 1,3-propanediol, butylene glycol, pentylene glycol, isomers thereof, mixtures thereof as well as their mixtures with water.

In some embodiments, the vehicle is preferably selected from glycerin and glycerin/water mixtures with a glycerin/water volume ratio greater than 1, preferably greater than 5 or greater than 10.

In a particular embodiment, the vehicle is glycerin.

In some embodiments, the vehicle is a C ₂ -C ₅ alkanediol or glycerin, preferably glycerin, comprising at most 5% by weight of water, eg from 1 to 2% by weight of water.

As indicated above, the LPCs are the majority phospholipid compounds present in the emulsifying agent according to the invention. In certain embodiments, the LPCs represent at least 65%, preferably at least 70%, more preferably at least 75%, even more preferably at least 80% or at least 90% by weight of the total weight of the phospholipids (i.e. the total weight of the phospholipids with one or two fatty chains together) present in the emulsifying agent.

For the purposes of the invention, the term “lysophosphatidylcholine” means a glycerophosphocholine molecule esterified in position 1 or 2 of glycerol by a fatty acid. Lysophosphatidylcholines (LPC) can be obtained by hydrolysis of a phosphatidylcholine (PC), for example enzymatically.

For example, the use of phospholipase A1 allows the selective hydrolysis of the fatty acid residue in position 1 of the glycerol of PC, thus giving 1-lysophosphatidylcholine (1-LPC).

As a further example, the use of phospholipase A2 allows the selective hydrolysis of the fatty acid residue at position 2 of the glycerol of PC thereby giving a 2-lysophosphatidylcholine (2-LPC). A preferred 2-LPC is for example a 2-LPC comprising an oleyl or linoleoyl residue.

For the purposes of the invention, lysophosphatidylcholines (LPC) include 1-lysophosphatidylcholines (1-LPC), 2-lysophosphatidylcholines (2-LPC) and mixtures thereof.

In some embodiments, the LPCs present in the emulsifying agent are of formula (I) or formula (II):

Formula (I)

Formula (II)

in which R ₁ and R ₂ independently represent a linear, saturated or unsaturated hydrocarbon chain comprising from 12 to 22 carbon atoms. Preferably R ₁ and R ₂ are chosen from saturated or unsaturated chains comprising from 14 to 20 carbon atoms, for example 17 or 18 carbon atoms. In certain embodiments, R ₁ and R ₂ are saturated hydrocarbon chains, or comprise at most two double bonds.

For example, the residues R ₁ C(O)O- and R ₂ C(O)O- are selected from stearyl, palmitoyl, oleoyl linoleoyl, and palmitoleyl residues, preferably oleoyl and linoleoyl.

In some embodiments, the emulsifying agent is characterized in that:

- 1-lysophosphatodylcholine (1-LPC) represents at least 3% by weight, preferably from 8% to 13% by weight, and

- 2-lysophosphatodylcholine (2-LPC) represents at least 75% by weight, preferably from 75% to 90% by weight of the total weight of the phospholipids present in the emulsifying agent.

As explained below, depending on the method for obtaining the LPC, the emulsifying agent may comprise residual contents of PC. PC is considered in the context of the invention as an impurity and its content is preferably less than 5% by weight relative to the total weight of the phospholipids present in the emulsifying agent.

In some embodiments, phosphatidylcholine (PC) is present as an impurity and represents at most 2.5%, preferably at most 1.5% or even at most 1.0% by weight relative to the total weight of phospholipids present in the emulsifying agent.

In other embodiments, the emulsifying agent may comprise phosphatidyl glycerol. The phosphatidyl glycerol represents at most 10%, preferably at most 5% or even at most 2.5% or 1% by weight of the total weight of the phospholipids present in the emulsifying agent.

The phospholipids enriched with at least 60% by weight of LPC may comprise other impurities such as phosphatidylserine, phosphatidylethanolamine, phosphatidylinositol, phospholipid acid as well as the lysophospholipids thereof. These impurities may represent at most 15%, preferably at most 10% and more preferably at most 7.0% by weight of the total weight of phospholipids.

In some embodiments, the emulsifying agent is characterized in that it has a phospholipid composition in which:

- the LPCs represent at least 85%, preferably at least 90% by weight of said phospholipids, and

- The PC represents at most 2.5% by weight, preferably at most 1.5% or even at most 1.0% by weight of said phospholipids.

Other phospholipids potentially present, e.g. phosphatidylserine, phosphatidylethanolamine, phosphatidylinositol, phosphatidic acid and the lysophospholipids thereof, represent at most 12.5%, preferably at most 7.5% or even at most 6.5% of the total weight of the phospholipids.

In certain embodiments, the emulsifying agent is characterized in that its LPC content is at least 5% by weight, preferably at least 9% by weight, more preferably at least 12% by weight or even at least 15% by weight relative to the total weight of the emulsifier.

In some preferred embodiments, the LPC content in the emulsifying agent is in a range of 10% to 25% by weight, even more preferably in a range of 12% to 18% by weight relative to the total weight of the emulsifying agent.

The emulsifying agent may optionally comprise an antioxidant agent. The antioxidant agent generally represents at most 5.0%, preferably at most 3.0%, more preferably at most 1.5% or even at most 1.0% or 0.5% by weight relative to the total weight of the composition.

For example, the antioxidant agent may be chosen from tocopherol, tocopherol acetate, ascorbic acid and its salts and esters, in particular ascorbyl palmitate or stearate, HMR (hydroxy methyl resorcinol), BHT (Butyl Hydroxy Toluene) or plant extracts, in particular rosemary. Preferably, the antioxidant agent is tocopherol.

In another embodiment, the emulsifying agent according to the invention may comprise one or more additional cosmetically acceptable excipients such as a vegetable oil, a preservative, a thickening agent or a gelling agent. The additional cosmetic excipient(s) may together represent at most 10.0%, preferably at most 5% or 2.5% by weight relative to the total weight of the emulsifying agent. Examples of suitable vegetable oil, preservative, thickening or gelling agent are cited later in the section dedicated to the topical compositions according to the invention.

In another embodiment, the emulsifying agent may contain an agent with a cosmetic effect, for example as mentioned later in the section dedicated to topical compositions according to the invention. These may be water-soluble active agents such as hyaluronic acid, liposoluble agents such as vitamins, triglycerides and essential oils as well as amphiphilic active agents such as caffeine.

In a particular embodiment, the emulsifying agent is characterized in that it

it includes or consists essentially of:

- from 5% to 30%, preferably from 15% to 25% by weight of phospholipids,

- from 65% to 94.9%, preferably from 75% to 84.9% by weight of glycerin or of a glycerin/water mixture in a volume ratio of at least 1/1, preferably at least 5/1 and

- optionally, at most 5.0%, preferably from 0.1% to 3.0% by weight of an antioxidant agent such as tocopherol,

the percentages being expressed by weight relative to the total weight of the emulsifying agent,

And

- in that the LPCs represent at least 70% or 80% by weight, preferably at least 85% or at least 90% by weight of the phospholipids present in the emulsifying agent.

For the purposes of the Invention, “consists essentially” means that the ingredients cited following this expression together represent at least 95%, preferably at least 96%, 97%, 98% or 99% by weight of the total weight of the emulsifying agent.

For example, the emulsifying agent is characterized in that:

it comprises or consists essentially of

- from 18% to 22% by weight of phospholipids,

- from 78% to 82% by weight of glycerin, and

- optionally, not more than 1.5% by weight of tocopherol, for example not more than 1.0% or not more than 0.5% by weight of tocopherol and

in that its composition in phospholipid position is such that the LPC represents at least 85% by weight or at least 90% of said phospholipids and the PC represents at most 1.5% by weight of said phospholipids.

As a further example, the emulsifying agent is characterized in that:

it comprises or consists essentially of

- 21% +/- 10% by weight of phospholipids,

- 78.5% +/- 10% by weight of glycerin, and

- optionally, not more than 0.5% +/-10% by weight of tocopherol, and

in that its composition in phospholipid position is such that the LPC represents at least 85% by weight or at least 90% of said phospholipids and the PC represents at most 1.5% by weight of said phospholipids.

- Preparation of the emulsifying agent according to the invention

According to a further aspect, the invention relates to a process for preparing an emulsifying agent according to the invention. Lysophosphatylcholine (LPC) is in the form of a very hard wax, which is difficult to disperse in water. It is possible to dissolve LPC in ethanol. However, ethanol is not suitable for use in most cosmetic products due to its irritating and drying properties. The Applicant has shown that it is possible to obtain a homogeneous and stable dispersion of LPC by using as a support a hydrophilic solvent such as glycerin, C ₂ -C ₅ alkanediols, mixtures thereof and their aqueous mixtures.

According to a particular aspect, the process for preparing an emulsifying agent according to the invention comprises the following steps:

(a) the provision of LPC-enriched phospholipids, and

(b) dispersing the phospholipids in a vehicle preferably chosen from C ₂ -C ₅ alkanediols, glycerin, mixtures thereof and their aqueous mixtures,

For the purposes of the invention, the term “LPC-enriched phospholipids” means a mixture of phospholipids comprising at least 60% by weight of LPC, preferably at least 70%, 75%, 80%, 85% or 90% by weight of LPC. It can thus be considered that “the LPC-enriched phospholipids” correspond to a lysophosphatidylcholine having a mass purity of at least 60%, preferably at least 70%, 75%, 80%, 85% or 90%.

As indicated above, the LPCs are divided into 1-LPC and 2-LPC. In some embodiments, 1-lysophosphatodylcholine (1-LPC) represents at least 3% by weight, preferably from 8% to 13% by weight, and 2-lysophosphatodylcholine (2-LPC) represents at least 75% by weight, preferably from 75% to 90% by weight of the total weight of the phospholipids. In some embodiments, the phospholipid composition has a residual content of PC, the PC being present as an impurity. Preferably, phosphatidylcholine (PC) represents at most 5.0%, preferably at most 2.5%, or even at most 1.5% or at most 1.0% by weight of the total weight of the starting phospholipids.

Said LPC-enriched phospholipids may have a residual content of phospholipids such as phosphatidylserine, phosphatidylethanolamine, phosphatidylinositol, phospholipid acid and the lysophospholipids thereof, of at most 12.5%, preferably at most 7.5% or even at most 6.5% by weight.

There are commercially available products called “lysolecithin”. However, contrary to what their name suggests, their actual content of lysophospholipids, and in particular of LPC, is very low. In other words, commercially available lysolecithins are generally not suitable for use in the preparation of the emulsifying agent according to the invention, without the implementation of a prior step (e.g. purification) making it possible to very significantly increase their LPC content.

In a particular embodiment, the LPC-enriched phospholipids provided in step (a) are obtained by hydrolysis of a purified phosphatidylcholine. Preferably, this hydrolysis step is carried out using a phospholipase. A preferred phospholipase is a phospholipase A2. Such a phospholipase makes it possible to hydrolyze the fatty chain present in position 2 of the glycerol of the PC and to generate mainly 2-LPC. The lysophospholipids and the fatty acids generated during the reaction can be separated by any known method, for example by ethanol extraction, so as to obtain a phospholipid composition having a low content of free fatty acids, for example a content of at most 5% by weight, preferably at most 2.5% by weight or at most 1.0% by weight.

The purified PC can be obtained by any known method, for example by chemical synthesis or by purification from a lecithin. Any type of lecithin can be used. It can be in particular a lecithin obtained from egg yolks, or from soybeans, rapeseed or sunflower seeds. Preferably, the lecithin is obtained from soybeans. The lecithin can be hydrolyzed or non-hydrolyzed. Preferably, it is a non-hydrogenated lecithin. It can be a commercial lecithin.

Typically, the PC used in the hydrolysis step can be obtained from a lecithin, e.g. from soy, by ethanolic extraction followed by a chromatography step on a suitable support, for example silica. The PC thus obtained preferably has a purity greater than 70% by mass.

In an alternative embodiment, the LPC-enriched phospholipids provided in step (a) may be obtained by chemical or enzymatic synthesis, by implementing an esterification step between glycerophosphocholine or one of its derivatives and a suitable fatty acid, for example by enzymatic means. The esterification step may further be followed by one or more purification steps by any known technique (e.g. extraction chromatography) so as to enrich the LPC content of the final product.

In step (b) the vehicle is added. This is preferably glycerin or a glycerin/water mixture in a volume ratio of at least 1/1, preferably at least 5/1 or even at least 10/1 or even at least 90/1. Step (b) is carried out with stirring, at room temperature or in the presence of slight heating, for example between 30°C and 50°C. The amount of vehicle added depends on the desired phospholipid/vehicle mass ratio in the final emulsifying agent. Step (b) generally lasts from 30 minutes to 6 hours.

It may be difficult to disperse the LPCs directly into the vehicle. Thus, in some embodiments, pre-solubilization in a suitable solvent, e.g., an alcohol, may be necessary.

According to an additional aspect, the invention relates to a process for preparing an emulsifying agent according to the invention which comprises the following steps:

(a1) the provision of LPC-enriched phospholipids,

(b1) solubilization of LPC-enriched phospholipids in an alcohol, preferably a C alcohol_{1 -}C₅ and hydroalcoholic mixtures thereof,

(c1) the addition of the vehicle preferably chosen from C ₂ -C ₅ alkanediols, glycerin, mixtures of these and their aqueous mixtures, and

(d1) elimination of alcohol.

Step (a1) is similar to step (a) above. Similarly, step (c1) is similar to step (b) above.

Step (b1) of the process for preparing the emulsifying agent according to the invention is carried out with stirring, at room temperature or in the presence of slight heating, for example between 30°C and 50°C. The C ₁ -C ₅ alcohols include, but are not limited to, methanol, ethanol, propanol, butanol and pentanol and their isomers such as isopropanol and tert-butanol. Preferably, the alcohol used is ethanol. Step (b) generally lasts from a few hours to a few days. 1L to 10L of alcohol are generally added per kilogram of starting phospholipids.

In step (d), the alcohol is removed by any suitable technique, in particular by condensation under reduced pressure.

Any antioxidant agent or any other excipients or active agents present in the final emulsifying agent may be added at any of the steps described above.

The method according to the invention may comprise one or more additional steps, in particular a bottling step.

- Uses of the emulsifying agent according to the invention, and composition s the container

The emulsifying agent according to the invention can be used in the preparation of topical compositions in the form of an emulsion, for cosmetic or pharmaceutical applications. The emulsifying agent according to the invention makes it possible to prepare micellar compositions or compositions in the form of an emulsion having increased stability and improved organoleptic properties, in particular a silky, soft and light and non-greasy feel, and having a fluid texture which can be adapted to administration by spraying.

Thus, according to a further aspect, the invention relates to the use of the emulsifying agent as described herein for the preparation of a topical composition as well as the topical composition as such.

The topical composition may be a pharmaceutical or cosmetic composition and is preferably suitable for application to the skin or any of its appendages.

For the purposes of the invention, the term " skin " means any part of the skin of the human body, in particular the skin of the face, including the lips and eyelids, the scalp, the neck, the skin of the hands and the skin of the feet. The appendages of the skin include nails, hair, eyebrows, eyelashes and hair, preferably hair.

Preferably, the topical composition is a cosmetic composition. It may in particular be a cosmetic care product, a hygiene product, a perfume or a makeup product. For example, the topical composition according to the invention may be chosen from a cream, a milk, a makeup remover, a micellar water, in particular a makeup remover, a mask, a shampoo, a conditioner, a shower gel, a lipstick, a foundation, a tinted cream (e.g. a BB cream), a cream-gel, a mascara, an eye shadow, an eyeliner, a serum, a perfumed water or mist, an aqueous perfume, a spray or a lotion, in particular a sunscreen.

The emulsifying agent according to the invention is generally present in said topical composition in a content of at most 10% by weight, preferably at most 5.0% by weight and at least 0.01%, for example from 0.1% to 5.0% or from 0.5% to 2.5% by weight relative to the total weight of the topical composition according to the invention.

In some embodiments, the topical composition according to the invention is an emulsion, preferably an oil-in-water emulsion. The mass ratio between the oily phase and the aqueous phase is generally at most 1.0, preferably at most 0.5, for example between 0.01 and 0.2. Preferably the oily phase (including the excipients and/or active agents that it comprises) represents at most 45%, preferably at most 25% or at most 15% by weight of the topical composition. The oily phase can be of any type, in particular a vegetable oil, a mineral oil, fatty acid triglycerides and their combination. Examples of oily carriers are provided below

In other embodiments, the topical composition according to the invention is a micellar water or a serum.

In some embodiments, the topical composition may include one or more additional cosmetically acceptable excipients such as a pH adjusting agent, an antioxidant agent, a preservative agent, an osmotic agent, a thickening or gelling agent, fragrances, and combinations thereof. When the topical composition includes an antioxidant or preservative agent, these molecules may be present in the oil phase (if present) or in the aqueous phase depending on their lipophilicity. The pH adjusting agents and osmotic agents are present in the aqueous phase.

Additional cosmetically acceptable excipients represent at most 15%, preferably at most 10% or at most 5% by weight of the total composition.

The antioxidant agents of interest include, but are not limited to, tocopherol, tocopheryl acetate, ascorbic acid and its salts and esters, in particular ascorbyl palmitate or stearate, or plant extracts, in particular rosemary. Generally, the antioxidant agent(s), when present, represent at most 5% by weight, preferably at most 1% by weight of the total weight of the composition.

Preservatives include, but are not limited to, pentylene glycol, glyceryl caprylate, octanediol, benzoic acid, sorbic acid, and salts thereof, preferably sodium or potassium, benzalkonium salts, for example benzalkonium chloride, and combinations thereof. Generally, the preservative(s), when present, represent at most 5% by weight, preferably at most 1% by weight of the total weight of the composition.

The pH adjusting agents include, but are not limited to, organic acids such as acetic acid, citric acid, tartaric acid, lactic acid, phosphoric acid and their salts, and inorganic acids and bases such as hydrochloric acid and sodium hydroxide. The pH adjusting agents are used in an amount to provide a pH suitable for application to the skin, e.g., a pH of between 5 and 8.

Gelling or thickening agents include, but are not limited to, collagen, starches, cellulose and its derivatives, for example HPMC, HPC, hydroxyethylcellulose or carboxymethylcellulose (also known as carmellose) and its salts, gelatin, pectin, hyaluronic acid and its salts, alginates, agar-agar, carrageenans, gums such as xanthan gum, sclerotium gum, gellan gum, gum arabic, konjac gum, tara gum, and mixtures thereof. Generally, the gelling or thickening agent(s), when present, represent at most 5% by weight, preferably at most 1% by weight of the total weight of the composition. Gelling agents may be present in particular in serums or emulsions according to the invention having a high oily phase content (e.g. at least 10%).

Osmotic agents include inorganic salts such as NaCl or KCl, and organic salts, especially of carboxylic acids such as citrate salts.

The cosmetic composition according to the invention may also comprise one or more active agents with a cosmetic effect. Without wishing to be bound by any theory, the Applicant is of the opinion that the emulsifying agent according to the invention makes it possible to improve the penetration and diffusion of the active ingredients in the skin, in particular through the stratum corneum and in the epidermis thanks to the fineness of the emulsions or micelles that it forms as well as to the affinity of the LPC for the intercellular lipids of the skin. The presence of lipophilic active agents with a cosmetic effect in the oily phase is particularly sought when the topical composition is a serum.

“ Cosmetic effect ” means any non-therapeutic effect aimed at modifying and/or improving the appearance of the skin or mucous membranes such as the lips, protecting them from external aggressions, preventing, treating and/or correcting non-pathological alterations of the skin or its appendages and/or preventing or treating feelings of discomfort of the skin or one of its appendages (in other words cutaneous discomfort).

Thus, in certain embodiments, the topical composition comprises one or more active agents chosen from soothing or anti-redness agents, anti-aging agents, including anti-wrinkle agents, anti-blemish agents, UV filters, moisturizing agents, sebum-regulating agents, slimming agents, lipid-replenishing or nourishing agents, emollient agents and combinations thereof.

Examples of soothing agents include panthenol, allantoin, licochalcone A, bisabolol, avenanthramides, madecassic acid, niacinamide, liquorice extracts, birch extracts, oat extracts, in particular oat plantlets, Epilobium augustifolium extracts, Calendula officialis extracts.

Examples of moisturizing agents include urea, pidolic acid (PCA) and its derivatives and salts, calcium gluconate, hyaluronic acid and its salts and other glycosaminoglycans, polyethylene glycols such as PEG-7, PEG-8, PEG-10, PEG-12 or PEG-14, glycerin, propylene glycol, pentylene glycol, butylene glycol, butanediol, betaine, citrulline, collagen and its derivatives, and combinations thereof.

An example of a slimming agent is caffeine.

As nourishing agents, we can cite vegetable oils such as olive oil, sweet almond oil, evening primrose oil, borage oil, shea butter, fatty acids, triglycerides, and ceramides.

Examples of emollient agents include coconut oil, cetearyl alcohol and its salts, liquid paraffin, polyglycerides of fatty acids such as caprylic/capric triglyceride, diesters of propylene glycol and fatty acids such as propylene glycol dicaprylate/dicaprate and combinations thereof.

Examples of anti-redness agents include saponins, flavonoids, ruscogenins, esculosides, and extracts containing them, for example Ruscus extracts, as well as certain essential oils, for example rosemary.

The active agents are generally present in a content of at most 5%, preferably from 0.01% to 2.0% by weight relative to the total weight of the composition.

The Applicant has shown that the emulsifying agent according to the invention is capable of forming very fine and stable emulsions making it possible to obtain emulsions with a translucent or even transparent appearance. Thus, the invention also relates to the use of the emulsifying agent according to the invention for the preparation of a topical composition in the form of a translucent or transparent emulsion.

In this type of application, the emulsifying agent is generally present in a content of at most 5% by weight in the topical composition. The emulsion is preferably an oil-in-water emulsion, the oily phase representing at most 20.0%, preferably at most 15% or at most 10.0%, for example at most 5.0% or at most 3.0% such as from 0.1% to 2.0% or from 0.5% to 1.5% by weight of the topical composition.

The topical composition is preferably a cosmetic composition such as a mist or perfumed water.

According to a particular aspect, the invention relates to a topical composition in the form of a translucent or transparent oil-in-water emulsion comprising the emulsifying agent according to the invention.

As indicated above, it may in particular be a perfumed water or mist. Preferably, said composition is sprayable. In other words, it can be applied to the skin by spraying.

Preferably, said composition comprises, or consists essentially of:

- from 0.1% to 20.0%, preferably from 0.1% to 15.0%, more preferably from 0.1% to 10.0% or from 0.1% to 5.0% by weight of an oily phase, and

- from 0.1% to 5.0% by weight of an emulsifying agent according to the invention

in the water

the percentages being expressed by weight relative to the total weight of the composition.

The aqueous phase is typically water. It may be purified water, deionized water or sterilized water. The aqueous phase may comprise one or more cosmetically acceptable excipients such as a pH adjusting agent, an antioxidant agent, a preservative agent, an osmotic agent, a thickening or gelling agent and combinations thereof, for example as described above. In some embodiments, the scented mist or water does not contain a thickening or gelling agent, in particular as described herein. In other embodiments, the scented mist or water comprises at most 5.0% by weight of thickening or gelling agent, in particular as described herein.

In the case of a scented water or mist, the oily phase comprises odorous molecules, in particular when the composition is a scented water or mist. The odorous or perfumed molecules may be chosen in particular from synthetic perfumes, perfume molecules of natural origin or extracts, in particular plant extracts such as absolutes, essential oils, an extract obtained by decoction, extraction or maceration using an organic, hydroalcoholic or aqueous solvent or by extraction by supercritical fluid.

Examples of scented molecules include compounds belonging to the terpene and terpinoid family such as linalool, geraniol, linalool acetate, limonene, alpha-pinene, menthol, nerol, citrollenol and combinations thereof.

Examples of odorous plant extracts include essential oils and absolutes obtained from plant species belonging to one of the following genera: Lavandula , Jasminum , Citrus, Narcissus , Acacia , Rosa , Polianthes , Chrysopogon , Cymbopogon and Ribes . As species of interest, we can cite lavender ( Lavandula angustifolia ), lavandin ( Lavandula hybrida ), mimosa ( Acacia dealbata ), bitter orange ( Citrus aurantium ), Arabian jasmine ( Jasminum sambac ), Spanish jasmine ( Jasminum grandiflorum ), tuberose ( Polianthes tuberosa ), blackcurrant bud (Ribes nigrum ) , vetiver ( Chrysopogon zizanioides ), lemongrass ( Cymbopogon citratus ), rose ( Rosa damascena and Rosa centifolia ).

In a preferred embodiment, the oily phase comprises, or consists of, one or more lipophilic plant extracts.

The oily phase may further comprise an oily carrier, preferably neutral. The oily carrier may be chosen from vegetable oils, for example sunflower oil, sweet almond oil, borage oil, rapeseed oil, evening primrose oil, coconut oil, argan oil, or avocado oil, and mineral oils such as paraffin oil. Preferably, the oily carrier is chosen from vegetable oils and combinations thereof.

In a particular aspect, the scented water or mist comprises or consists essentially of:

- from 0.1% to 5.0%, preferably from 0.5% to 2.0% of an oily phase comprising odorous molecules,

- from 0.1% to 5.0%, preferably from 0.5% to 2.0% by weight of the emulsifying agent according to the invention,

- not more than 5.0% by weight of preservative,

in the water.

The scented water or mist according to the invention may optionally comprise:

- a pH adjusting agent and/or an osmotic agent, and

- at most 5.0%, preferably from 0.01% to 3.0% by weight of one or more active agents with a cosmetic effect preferably chosen from soothing agents, moisturizing agents, anti-redness agents, anti-UV agents, vitamins and combinations thereof.

The pH of the water or scented mist is preferably in the range of 5.0 to 7.5.

In some embodiments, the mist or perfumed water according to the invention is free of ethanol. In other words, said mist or perfumed water can be used as an alcohol-free perfume composition.

According to an additional aspect, the emulsifying agent according to the invention can be used to homogeneously disperse odorous molecules in water, for example to obtain a perfumed water as indicated above, but also to prepare perfumes having a low ethanol content, e.g. of at most 50% by weight, said perfumes having a translucent or even transparent appearance.

Thus, according to a particular aspect, the invention also relates to a perfume composition comprising:

- at most 5% by weight of the emulsifying agent according to the invention, preferably from 0.1% to 3.0% by weight

-at most 10% by weight of odorous molecules, preferably from 0.1% to 5.0% by weight,

- at most 50% by weight of ethanol, preferably from 10% to 45% by weight of ethanol

in the water,

the percentages being expressed by weight relative to the total weight of the composition.

In some embodiments, the fragrance is alcohol-free and may include or consist of

- at most 5% by weight of the emulsifying agent according to the invention, preferably from 0.1% to 3.0% by weight and

-at most 10% by weight of odorous molecules, preferably from 0.1% to 5.0% by weight,

In the water.

The odorous molecules can be of any type. They can be synthetic odorous molecules, odorous molecules of natural origin, or even extracts, in particular plant extracts, as described above, for example essential oils or absolutes.

The fragrance composition may further comprise one or more cosmetically acceptable excipients, for example an antioxidant, a preservative, a pH adjusting agent, and combinations thereof.

The Applicant has also shown that the emulsifying agent according to the invention makes it possible to obtain transparent micellar waters. The emulsifying agent can thus be used as an alternative to compounds comprising polyethylene glycol type chains such as polysorbates, the use of which is increasingly controversial due to its manufacturing process (heavy chemistry) and potential health risks.

Thus, according to an additional aspect, the invention also relates to the use of an emulsifying agent according to the invention for the preparation of a transparent micellar water.

The invention also relates to micellar water as such. Said micellar water can find different uses in the cosmetic field, in particular as a skin cleansing agent, or as a makeup remover preferably without rinsing. Said micellar water can also be in the form of a transparent serum. In this case it may comprise a thickening or gelling agent as described herein, in particular collagen, starches, cellulose and its derivatives, for example HPMC, HPC, hydroxyethylcellulose or carboxymethylcellulose (also known as carmellose) and its salts, gelatin, pectin, hyaluronic acid and its salts, alginates, agar-agar, carrageenans, gums such as xanthan gum, sclerotium gum, gellan gum, gum arabic, konjac gum, tara gum, and mixtures thereof. Generally, the gelling or thickening agent(s), when present, represent at most 5% by weight, preferably at most 1% by weight of the total weight of the composition. The serum may further comprise one or more active agents.

The micellar water or serum according to the invention comprises, or essentially consists of, at most 5% by weight of the emulsifying agent in the water. The micellar water may further comprise one or more cosmetically acceptable excipients such as a pH adjusting agent, a fragrance, an antioxidant agent, a preservative and combinations thereof. These additional excipients represent at most 10% by weight, preferably 5.0% by weight, of the micellar water.

The micellar water or serum may further comprise one or more agents with a cosmetic effect as described above, for example a soothing agent, a moisturizing agent, an anti-redness agent, vitamins and combinations thereof.

The topical compositions described above, in particular the perfumed mists or waters, serums, micellar waters and alcohol-depleted perfume compositions according to the invention, are preferably free of polysorbate-type emulsifying agent. In certain embodiments, the emulsifying agent according to the invention is the only emulsifying agent present in the composition.

In other additional embodiments, the topical composition according to the invention, in particular the mists or perfumed waters, is free of thickening agent or gelling agent, as indicated above.

According to an additional aspect, the invention also relates to a method of preparing a topical composition as described above, in which the emulsifying agent is added with stirring to an aqueous phase and/or to an oily phase.

Other aspects and advantages of the present invention will appear on reading the following examples, which should be considered as illustrative and in no way as limiting.

EXAMPLES

1/ Example 1: Emulsifying agent - Preparation process according to the invention and characterization.

A phospholipid mixture enriched in LPC was obtained from commercial soy lecithin under standard conditions. The soy lecithin was subjected to a chromatography step to obtain a PC-enriched fraction. This PC-enriched fraction was treated with a phospholipase A2 to obtain a phospholipid mixture containing an LPC content of at least 80% by weight.

Preparation of the emulsifying agent

a) phospholipid mixture enriched with LPC: 20%

b) Glycerin: 79.5%

c)Tocopherol: 0.5%

b) and c) are mixed for 30 min.

The phospholipid mixture is then added. The resulting mixture is heated to 30°C and kept stirring for 24 hours.

A brownish viscous mixture is obtained.

2/ Example 2: Cosmetic compositions

The following cosmetic compositions were prepared. The stability of the compositions is evaluated as follows:

- centrifugation test: the cosmetic preparation is packaged in transparent centrifuge tubes. The tubes are then centrifuged for 20 min at 3,000 rpm. The tubes are then visually observed. If no phase shift is observed, the emulsion is considered stable.

- 40°C stability test: The cosmetic preparation is packaged in transparent glass bottles and then stored in an oven at 45°C for 3 months. After this period, the bottles are observed. If the product is not phase-shifted and has not undergone any degradation, the product is considered stable.

The size of the micelles or droplets was evaluated by optical microscopy. The size of the droplets is measured at D+7 after manufacture in the different formulas with a magnification of 250.

a) Preparation of a micellar water according to the invention and comparison with a micellar water obtained with a lecithin.

The following micellar waters are prepared:

Micellar water according to the Invention:

Ingredients % by mass HAS Water 92.7% Pentylene glycol 2.0% Sodium benzoate 0.3% Emulsifying agent according to the invention (glycerin AND lysophosphatidylcholine AND tocopherol) 5.0%

Comparative

Ingredients % by mass HAS Water 92.7% Pentylene glycol 2.0% Sodium benzoate 0.3% Soy lecithin 1.0% Glycerin 4.0%

Results :

The micellar water obtained with the emulsifying agent according to the invention is a liquid formula, slightly colored and completely transparent. In comparison, the micellar water obtained with an equivalent quantity of lecithin is yellowish and completely opaque.

b) preparation of an emulsion according to the invention and comparison with an emulsion obtained with a lecithin in the presence of a gelling agent

Emulsion according to the Invention:

Ingredients % by mass HAS Water 71.7 Pentylene glycol 2 ,0 Sodium benzoate 0.3 Glycerin 4.0 Hydroxyethylcellulose 1.0 Soy lecithin 1.0 B Caprylic/capric triglyceride 9.0 Propylene glycol dicaprylate./dicaprate 11.0

Comparative

Ingredients % by mass HAS Water 75.7 Pentylene glycol 2 ,0 Sodium benzoate 0.3 Hydroxyethylcellulose 1.0 Emulsifier according to the invention 1.0 B Caprylic/capric triglyceride 9.0 Propylene glycol dicaprylate./dicaprate 11.0

Results :

The emulsion obtained with the emulsifying agent of Example 1 is stable. No phase separation is observed after centrifugation at 3000 rpm for 20 min. The emulsion is white and smooth. The emulsion has a soft and silky feel.

The emulsion obtained with soy lecithin is yellowish and has a soft but greasy feel. The emulsion separates after centrifugation.

The photograph obtained by optical microscopy of the emulsion with soy lecithin (1%) at D+12, magnification x250 is presented in

The photograph obtained by optical microscopy of the emulsion with the emulsifier according to the invention (1%) at D+12, magnification x250 is presented in .

These images show that a much greater fineness of emulsion is obtained with the emulsifier according to the invention, allowing much greater stability, a whiter appearance and a better feel.

c) Clear scented water

The following scented water was prepared as follows:

Phase Ingredients % by mass HAS Water
Sodium benzoate (preservative)
Pentylene glycol (preservative) Qsp
0.3%
2.0% B Emulsifying agent according to the invention (glycerin AND lysophosphatidylcholine AND tocopherol) 0.5% C Scent 0.35% D Lactic acid 20% Add until pH 5-6 is obtained

Steps:

- Prepare phase A, stir at 300 rpm for 5 min

- Mix phases B and C together, then add to phase A. Keep stirring at 600 rpm for 10 min.

- If necessary, adjust the pH to 5-6 by adding lactic acid (while stirring).

Results :

A transparent and sprayable scented water is obtained. The emulsion is stable for at least 3 months at 45°C. This scented water is easily applied to the hair or skin by spraying. After evaporation of the water, the skin and hair remain scented. The product leaves a film on the hair, improving its hydration and giving it a silkier effect.

d) Transparent serum according to the invention

Phase Ingredients % by mass A1 Water Qsp Sodium benzoate (preservative) 0.30% A2 Pentylene glycol (preservative) 2.00% Xanthan gum (XXX) 0.40% Sclerotium gum (XXX) 0.40% Emulsifying agent according to the invention (glycerin AND lysophosphatidylcholine AND tocopherol) 1.0% Skin protective agent (Glycerin AND Water AND Porphyridium Cruentum extract. 2.0% Lactic acid 20% Add until pH 5-6 is obtained

- Mix the ingredients of phase A1, stir at 300 rpm for 2 min

- Mix the gums and pentylene glycol. Add the mixture to phase A1 while stirring (600 rpm). Control the stirring speed to avoid the formation of bubbles.

- Add the emulsifying agent to phase A1 while stirring at 600 rpm for 5 min.

- Add the protective agent at 1040 rpm.

- If necessary, adjust the pH to 5-6 by adding lactic acid (while stirring).

Results :

A transparent, slightly pink serum is obtained. The serum is stable for at least 3 months at 45°C. The serum has a soft, non-greasy feel on the skin and provides a feeling of freshness and hydration.

Claims (18)

Emulsifying agent characterized in that it comprises from 5% to 30% by weight of phospholipids enriched in lysophosphatidylcholine (LPC) and from 70% to 95% by weight of a solvent chosen from the group consisting of glycerin, C ₂ -C ₅ alkanediols, mixtures thereof as well as aqueous mixtures thereof. Emulsifying agent according to claim 1, characterized in that its phospholipid composition is such that:
- the LPCs represent at least 60% by weight, preferably at least 75% by weight of the total weight of said phospholipids, and
- phosphatidylcholine (PC) represents at most 5%, preferably at most 2.5% by weight of the total weight of said phospholipids. Emulsifying agent according to claim 1, characterized in that its phospholipid composition is such that:
- 1-lysophosphatidylcholine (1-LPC) represents at least 3% by weight, preferably from 8% to 13% by weight of the total weight of said phospholipids
- 2-lysophosphatidylcholine (2-LPC) represents at least 75% by weight, preferably from 75% to 90% by weight of the total weight of said phospholipids. Emulsifying agent according to any one of claims 1 to 3, characterized in that it optionally comprises an antioxidant agent, preferably tocopherol. An emulsifying agent according to any preceding claim comprising from 10% to 25% by weight of LPC, preferably from 12% to 18% by weight of LPC. Topical composition, preferably cosmetic, characterized in that it comprises the emulsifying agent according to one of claims 1 to 5, preferably in a content of at most 10% by weight. Topical composition according to claim 6, characterized in that the topical composition is chosen from a cosmetic care product, a hygiene product, a perfume and a makeup product, preferably from a cream, a cream gel, a milk, a makeup remover, a micellar water, in particular a makeup remover, a mask, a shampoo, a conditioner, a shower gel, a lipstick, a foundation, a tinted cream (e.g. a BB cream), a mascara, an eye shadow, an eyeliner, a serum, a spray or a lotion, in particular a sunscreen, a perfumed water or mist and an aqueous perfume. Cosmetic composition according to claim 7, characterized in that it is a transparent oil-in-water emulsion. Cosmetic composition according to claim 8, characterized in that it is a perfumed water or a transparent perfumed mist. 0 Cosmetic composition according to claim 9, characterized in that it comprises or consists essentially of
- from 0.1% to 5.0%, preferably from 0.5% to 2.0% of an oily phase comprising odorous molecules,
- from 0.1% to 5.0%, preferably from 0.5% to 2.0% by weight of the emulsifying agent as defined in one of claims 1 to 5,
- optionally up to 5.0% by weight of preservative,
in the water. 11. Micellar water or transparent serum for topical application, characterized in that it comprises the emulsifying agent according to any one of claims 1 to 5 in a content of at most 5% by weight in water. Aqueous perfume composition comprising:
- at most 5% by weight of the emulsifying agent as defined in one of claims 1 to 5,
-at most 10% by weight of odorous molecules, preferably from 0.1% to 5.0% by weight,
- at most 50% by weight of ethanol, preferably from 10% to 45% by weight of ethanol
in the water,
the percentages being expressed by weight relative to the total weight of the composition. Use of the emulsifying agent according to one of claims 1-5 for the preparation of an oil-in-water emulsion or a translucent, preferably transparent, micellar water. Use of the emulsifying agent according to one of claims 1-5 for stabilizing topical compositions in the form of an emulsion and for improving their organoleptic properties, in particular for providing a soft and non-greasy feel. Use of the emulsifying agent according to one of claims 1-5 for the preparation of perfume with reduced ethanol content. Use of the emulsifying agent according to one of claims 1-5 for stabilizing the dispersion of lipophilic odorous molecules in water. Use of the emulsifying agent according to one of claims 1-5 for increasing the penetration and diffusion of a lipophilic active agent into the skin. 18. Process for preparing the emulsifying agent according to one of claims 1-5 comprising the following steps:
(a) the provision of phospholipids comprising at least 60% by weight of LPC,
(b) adding a vehicle preferably chosen from C ₂ -C ₅ alkanediols, glycerin, mixtures thereof and their aqueous mixtures, so as to obtain a dispersion.
said method possibly comprising a step of pre-solubilization of the phospholipids in an alcohol or a hydroalcoholic mixture before dispersion in the vehicle and removal of the alcohol, once the dispersion has been obtained.