FR2735361A1 - Dispersion used to protect skin or hair esp. against UV light - Google Patents

Abstract

A dispersion contains (i) metal oxide pigment(s) and (ii) bubbles formed by a lipid membrane enclosing a liq phase, with the pigment encapsulated inside the bubbles.

Description

COMPOSITIONS CONTAINING LIPID VESICLES COMPRISING
NANOPIGMENTS
The present invention relates to a photostable composition containing pigments, used in particular in cosmetics or dermatology. More specifically, the invention relates to a composition comprising a dispersion of vesicles formed of a lipid membrane surrounding a liquid phase and pigments of at least one metal oxide encapsulated within these vesicles.

The invention also relates to a process for the preparation of these photostable pigmented compositions and their application to the treatment of skin and hair.

Pigments, and more particularly nanopigments of metal oxides are increasingly used in solar products and day products, especially makeup, given their scattering properties and reflection of UV radiation which gives them a great interest in terms of photoprotection: used alone, they provide good protection against UV rays; associated with organic filters, they make it possible to produce highly photoprotective products.

However, some of these metal oxide pigments, such as, for example, iron, zinc or cerium titanium oxides, exhibit photoreactivity, the consequences of which are often detrimental to the quality of the product.

In particular, the oxides of zinc and titanium undergo photooxidation and may react with other products of the composition containing them, or with the lipids of the skin, causing degradation of the latter. This results in an inefficiency of the composition and / or deterioration of the cutaneous tissue.

In addition, there is instability in the light of compositions comprising titanium oxide pigments. This instability is reflected, during the storage in the absence of oxygen of these products exposed to the light of day, by a blue coloring. This photocoloration, known as photobluing, only really affects the outer layers of products but is obviously not desirable from an aesthetic point of view.

Faced with these inconveniences, surface-treated pigments have appeared on the market in order to limit this phenomenon of photoreactivity. Many publications have also sought to solve this problem.
BOOTS EP-B-0 461130 protects TiO2 particles treated with phosphate anions. Similarly, it is known in cosmetics to use surface-treated TiO 2 pigments with silica or alumina. However, this treatment is expensive and difficult to implement.

Finally, while it is true that these surface treatments make it possible to reduce the photoinstability of the metal oxide pigments, and in particular the photobluing of the formulations containing TiO 2 pigments, this reduction is however not sufficient.

 There is therefore a need for photostable compositions containing metal oxide pigments. It is therefore useful to provide simpler and more effective solutions than those proposed by the state of the art and applicable to all photoreactive metal oxides.

The Applicant has surprisingly found that the introduction of the metal oxide pigments within lipid vesicles, and preferably within oily globules coated with a lamellar liquid crystal phase, significantly reduces the phenomenon of photoreaction. of these pigments.

This discovery is the basis of the invention.

The subject of the present invention is therefore a composition comprising pigments of at least one metal oxide and a dispersion of vesicles formed of a lipid membrane surrounding a liquid phase, characterized in that these pigments are encapsulated inside said vesicles .

The composition according to the invention has the advantage of being much more stable in light than the compositions of the prior art. In the particular case of compositions containing titanium oxide pigments, the photobluing observed during exposure of the compositions to light in the absence of oxygen is very low, or even zero.

The composition according to the invention also has excellent photoprotective power.

The subject of the invention is also a process for the preparation of an aqueous dispersion of photostable lipid vesicles, comprising pigments of metal oxides, characterized in that the vesicles are formed in the presence of the pigments.

Thus, and in accordance with the present invention, it is now possible to prepare photostable dispersions containing photoreactive metal oxide pigments.

Another object of the invention is the use of the compositions according to the invention as, or for the manufacture of, cosmetic compositions for the protection of the skin and / or the hair.

Another object of the invention is a method of protecting pigments against exposure to light by encapsulating these pigments within vesicles formed of a lipid membrane surrounding a liquid phase.

The lipid vesicles of the invention comprise a mono- or plurilamellar membrane of ionic or nonionic lipids which may contain an aqueous phase (lipid vesicles with an aqueous core) or an oily phase (lipid vesicles with an oily heart). Lipid vesicles with an aqueous core are known as liposomes.

Other features, aspects and advantages of the present invention will appear on reading the detailed description which follows.

The composition according to the invention is of the emulsion type, especially oil in water (O / W), containing lipid vesicles, preferably oily heart. Preferably, these lipid vesicles with oily heart are oily globules provided with a blade liquid crystal coating. In particular, these vesicles are of the type described in the European patent application EP-A-0 641 557.

Thus, according to a first preferred embodiment of the invention, each oily globule is individually coated with a monolamellar or oligolamellar layer obtained from at least one lipophilic surfactant, at least one surfactant, hydrophilic active agent and at least one fatty acid, and the aqueous phase of the emulsion according to the invention contains in the dissolved state a basic agent.

The lipophilic surfactant may be selected from the group consisting of sucrose distearate, diglyceryl distearate, tetraglyceryl tristearate, decaglyceryl decastearate, diglycerol monostearate, hexaglyceryl tristearate, decaglyceryl pentastearate, sorbitan monostearate, sorbitan tristearate, diethylene glycol monostearate, glycerol and palmitic acid and stearic acid ester, polyoxyethylenated monostearate 2
EO (comprising 2 units of ethylene oxide), glyceryl mono and dibehenate, pentaerythritol tetrastearate. Preferably, the lipophilic surfactant is sucrose distearate.

The lipophilic surfactant preferably has an HLB (hydrophilelipophilic balance) ranging from 2 to 5.

The hydrophilic surfactant may be selected from the group consisting of polyoxyethylenesorbitan monostearate, 4 EO, polyoxyethylene 20E sorbitan tristearate, polyoxyethylene 8 EO monostearate, hexaglyceryl monostearate, polyoxyethylenated EO monostearate, distearate polyoxyethylenated 12 EO, polyoxyethylene methylglucose distearate 20 EO.

Preferably, the hydrophilic surfactant is polyoxyethylenesorbitan monostearate 4 EO.

The hydrophilic surfactant preferably has an HLB of 8 to 12.

According to an alternative embodiment of the invention, the lipophilic surfactant and the hydrophilic surfactant each comprise at least one saturated fatty chain having more than 12 carbon atoms, preferably ranging from 16 to 22 carbon atoms. carbon.

According to one embodiment variant of the invention, the fatty acid comprises at least one saturated fatty chain having more than 12 carbon atoms, preferably ranging from 16 to 22 carbon atoms. Preferably, the fatty acid is selected from the group consisting of palmitic acid, stearic acid, arachidic acid and behenic acid. Even more preferably, the fatty acid is stearic acid.

Examples of basic agents may be sodium hydroxide, triethanolamine, lysine or arginine. Preferably, the basic agent is sodium hydroxide.

The basic agent is dissolved in the aqueous phase in an amount at least equal to the amount necessary for the neutralization of the fatty acid.

According to a second preferred embodiment of the invention, the lipid vesicles are of the type described in the patent application EN 9412005 filed in the name of the Applicant. Thus, in accordance with this application, the lipid vesicles are unitarily oily globules coated with a monolamellar or oligolamellar layer obtained from at least one lipophilic surfactant and at least one hydrophilic surfactant such as those defined above and also from at least one ionic amphiphilic lipid imparting to the emulsion a pH ranging from 5.5 to 7.5.

The ionic amphiphilic lipid used in the context of the present invention is preferably chosen from the group comprising neutralized anionic lipids, amphoteric lipids and alkylsulphonic derivatives.

The neutralized anionic lipids are chosen in particular from - the alkaline salts of dicetylphosphate, and in particular the sodium and potassium salts - the alkaline salts of dimyristylphosphate, and in particular the sodium and potassium salts - the alkaline salts of sulfate cholesterol , and in particular the sodium salt - the alkaline salts of cholesterol phosphate, and in particular the sodium salt - the monosodium and disodium salts of acylglutamic acids, and in particular the monosodium and disodium salts of N-stearoyl glutamic acid, the sodium salt of phosphatidic acid.

The amphoteric lipids are chosen in particular from phospholipids and in particular phosphatidylethanolamine from pure soybean.

dans laquelle R représente les radicaux C16H33 et C18H37 pris en mélange ou séparément et M est un métal alcalin, de préférence le sodium.The alkylsulphonic derivatives are advantageously the compounds of formula

wherein R represents the radicals C16H33 and C18H37 taken as a mixture or separately and M is an alkali metal, preferably sodium.

Preferably, the ionic amphiphilic lipid is the monosodium salt of Nstearoyl glutamic acid sold under the trade name Acylglutamate
HS11 by Ajinomoto.

The coating according to the second embodiment of the invention of oily globules is preferably obtained by the use of a total amount of hydrophilic surfactant, lipophilic surfactant and ionic amphiphilic lipid included between about 2% and about 6% by weight relative to the total weight of the composition. Even more preferentially, this amount is between 3% and 4%. The relative amounts of lipophilic, hydrophilic and ionic amphiphilic lipid surfactants preferably vary in the following respective ranges: 35-55% / 2540% / 15-35% by weight based on their total weight.

The fatty phase, and in particular that of the coated oily globules, preferably represents 5 to 50% by weight relative to the total weight of the composition.

Even more preferentially, this percentage is between 10 and 40%. Preferably, the oil / water ratio is equal to or less than 1.

The weight ratio of the oily globules to the constitutive elements of the coating is preferably from 2 to 13; even more preferably this ratio is equal to about 7.

According to the invention, the pigments of at least one metal oxide are preferably nanopigments. By nanopigment is meant a pigment whose average size of the elementary particles is chosen from 5 to 100 nm.

The pigments may be treated or untreated on the surface and may be chosen from titanium oxide pigments (amorphous or crystallized in rutile and / or anatase form), iron, zirconium, zinc or cerium.

The treated pigments are pigments which have undergone one or more surface treatments of a chemical, electronic, mechanochemical and / or mechanical nature with compounds as described, for example, in Cosmetics & Toiletries,
February 1990, Vol. 105, p 53-64, such as amino acids, beeswax, fatty acids, fatty alcohols, anionic surfactants, lecithins, sodium, potassium, zinc, iron, or aluminum salts. fatty acids, metal alkoxides (titanium or aluminum), polyethylene, silicones, proteins (collagen, elastin) alkanolamines, silicon oxides, metal oxides or sodium hexametaphosphate.

The treated pigments may more particularly be titanium oxides treated with: silica and alumina such as MICROTITANIUM DIOXIDE MT 500 products
SA and MICROTITANIUM DIOXIDE MT 100 SA from the company TAYCA, and the products TIOVEIL Fin, TIOVEIL OP, TIOVEIL MOTG and TIOVEIL
IPM from the company TIOXIDE, alumina and aluminum stearate such as the product MICROTITANIUM
DIOXIDE MT 100 T from TAYCA - alumina and aluminum laurate such as MICROTITANIUM
DIOXIDE MT 100 S from TAYCA, - iron oxides and iron stearate such as MICROTITANIUM
DIOXIDE MT 100 F from TAYCA, - silica, alumina and silicone such as MICROTITANIUM products
DIOXIDE MT 100 SAS, MICROTITANIUM DIOXIDE MT 600 SAS and MICROTITANIUM DIOXIDE MT 500 SAS from the company TAYCA, sodium hexametaphosphate such as the product MICROTITANIUM
DIOXIDE MT 150 W from the company TAYCA, octyltrimethoxysilane such as the product T-805 from the company Degussa, - alumina and stearic acid such as the product UVT-M160 company
KEMIRA, - Alumina and glycerine such as the UVT-M212 product of the company
KEMI RA, - alumina and silicone such as the UVT-M262 product of the company
Kemira.

The untreated titanium oxides may, for example, be those sold by Tayca under the trade names MICROTITANIUM
DIOXIDE MT 500 B or MICROTITANIUM DIOXIDE MT 600 B.

The untreated zinc oxides may for example be those sold by the company SUMITOMO under the name ULTRA FINE ZINC OXIDE
POWDER, by the company PRESPERSE under the name FINEX 25, by the company IKEDA under the name MZO-25 or by the company
SUNSMART under the name Z-COTE. The treated zinc oxides may for example be those sold by Sunsmart under the name Z-Cote HP 1.

The metal oxide pigments may be present in the compositions according to the invention in a proportion ranging from 0.5 to 30% by weight relative to the total weight of the composition, preferably from 2 to 20%.

The invention can be applied in any field where it is desired to protect natural or artificial light particles of metal oxides.

The compositions of the invention, preferably cosmetic or dermatological, can be used as protective compositions of the human epidermis or hair against ultraviolet rays, as sunscreen compositions or as makeup or care products. They can be in the form of creams, milks, or fluid lotions.

The compositions according to the invention may also contain one or more cosmetically or dermatologically active hydrophilic or lipophilic compounds, free or encapsulated in the vesicles.

They may in particular contain a fatty or lipophilic substance chosen from antioxidants, anti-free radicals, moisturizers, melanoregulators, tanning accelerators, depigmenting agents, skin-coloring agents, liporegulators, slimming agents, anti-acne agents, antiseborrhoeic agents, anti-aging agents and anti-wrinkles, anti-UV, keratolytic, anti-inflammatory, refreshing, healing, vascular protective, antibacterial, antifungal, antiperspirants, deodorants, hair conditioners, immunomodulators, nourishing and essential oils and fragrances.

When the compositions in accordance with the invention are of antisolar application, they may of course contain one or more active and hydrophilic or lipophilic UVA and / or UVB (absorbent) sunscreens. These filters may be chosen in particular from cinnamic derivatives, salicylic derivatives, camphor derivatives, triazine derivatives, benzophenone derivatives, dibenzoylmethane derivatives, ss, -diphenylacrylate derivatives, acid derivatives. p-aminobenzoic, the filter polymers and silicone filters described in the application WO-93/04665. Other examples of organic filters are given in patent application EP-A 0 487 404.

The compositions according to the invention may also contain agents for tanning and / or artificial browning of the skin (self-tanning agents), such as, for example, dihydroxyacetone (DHA).

The compositions of the invention may furthermore comprise conventional cosmetic adjuvants, chosen in particular from fatty substances, organic solvents, ionic or nonionic thickeners, softeners, hydrophilic antioxidants, opacifiers, stabilizers, emollients and silicones. , α-hydroxyacids, anti-foam agents, hydrophilic moisturizers, vitamins, perfumes, preservatives, surfactants, fillers, sequestering agents, polymers, propellants, alkalinizing or acidifying agents, dyes, or any other ingredient usually used in cosmetics, in particular for the manufacture of sunscreen compositions in the form of emulsions.

The fatty substances may be an oil or a wax or mixtures thereof, and they also include fatty acids, fatty alcohols and fatty acid esters. The oils may be chosen from animal, vegetable, mineral or synthetic oils and in particular from liquid petroleum jelly,
Paraffin oil, silicone oils, volatile or not, isoparaffins, poly-α-olefins, fluorinated and perfluorinated oils. Similarly, the waxes can be chosen from animal, fossil, vegetable, mineral or synthetic waxes known per se.

Among the organic solvents, mention may be made of lower alcohols and polyols.

The thickeners may be chosen in particular from crosslinked polyacrylic acids, guar gums and modified or unmodified celluloses such as hydroxypropyl guar gum, xanthan gum, methylhydroxyethylcellulose, hydroxypropylmethylcellulose or else hydroxyethylcellulose.

The invention also consists of a process for the preparation of the compositions defined above, characterized in that it comprises the following steps
(i) mixing a phase containing pigments with an aqueous phase,
(ii) the mixture obtained is refined after step (i).

Concrete but non-limiting examples illustrating the process and compositions according to the invention will now be given.

The Applicant has carried out comparative tests. For this, four emulsions 1, 2, 3 and 4 were produced, whose characteristics and formulations in% by weight relative to the total weight of the compositions are given below:
Emulsion 1: the emulsifying system is conventional; it does not form lipid vesicles with an oily heart, the titanium oxide is conventionally incorporated in the fatty phase before the formation of the emulsion.

Phase A.

Mixture of glycerol mono stearate / PEG stearate (1000E) sold under the trade name Arlacel 165 by ICI 2.25%
Stearic acid 0.75% 2,2,4,4,6,6,8 Heptamethylnonane sold under the trade name Arlamol HD by ICI 15%
TiO2 sold under the trade name MT-1 00T by Tayca 10%
Phase B:
Glycerol 3% Soda (10%) 0.1%
Demineralized water qs 100%
Phase C:
Hydroxyethylcellulose PM 1,300,000 sold under the trade name Natrosol 250HHR by Aqualon 0.5%
Xanthan gum sold under the trade name Keltrol T by Kelco 0.4%
Demineralized water 19%
Conservatives qs
Operating mode ::
Emulsion 1 was prepared according to the following procedure: phase A and B were heated to 80 ° C. Phase B was then poured into phase A with stirring with a Moritz Turbolab 2100 apparatus at a rate of 3500 rpm. The mixture is allowed to stir for a few minutes, then the phase is added.
C, still stirring at Moritz.

Emulsion 2 - the emulsifying system, in accordance with that of the emulsions of the patent application EP-A-0 641 557, comprises a lipophilic surfactant, a hydrophilic surfactant, a fatty acid and a basic agent in the dissolved state. in its aqueous phase: the mixture is ground to obtain lipid vesicles with oily heart, - titanium oxide is incorporated in the emulsion after the formation of lipid vesicles with oily heart, and is therefore not encapsulated at inside these vesicles.

Phase A:
Sucrose di-stearate 1.35%
Oxyethylenated sorbitan mono-stearate (4 EO) sold under the trade name Tween 61 by ICI 0.9%
Stearic acid 0.75% 2,2,4,4,6,6,8 Heptamethylnonane sold under the trade name Arlamol HD by ICI 5%
Phase B.

TiO 2 sold under the trade name MT-100T by Tayca 10% 2,2,4,4,6,6,8 Heptamethylnonane sold under the trade name Arlamol HD by ICI 10%
Phase C:
Glycerol 3%
Soda 10%) 0.1%
Demineralized water qs 100%
Phase D:
Hydroxyethylcellulose MW 1,300,000 sold under the trade name Natrosol 250HHR by Aqualon 0.5%
Xanthan gum sold under the trade name Keltrol T by Kelco 0.4%
Demineralized water 19%
Conservatives qs
Operating mode:
Emulsion 2 was prepared according to the following procedure: phase A and C were heated to 80 ° C. Phase C was poured into phase A with stirring at room temperature.
Moritz Turbolab 2100 at the speed of 3500 rpm. Stirring and temperature conditions are maintained for 15 to 30 minutes.

The mixture is then introduced into a Rannie homogenizer set at a pressure of 107 Pa for 3 consecutive passages. An O / W emulsion based on oily lipid vesicles is then obtained.

Then added to this emulsion, with stirring with Moritz Turbolab 2100 at a speed of 3000 rpm, the phase B containing the pigment which has been previously dispersed in the oil with stirring with an Ultra-Turrax device.

This mixture is then introduced into a Dynomill KDL type ball mill set for two consecutive passes to obtain a more efficient grinding of the pigment.

Finally, this emulsion is added phase D with stirring Moritz Turbolab 2100.

Emulsion 3: the emulsifying system is the same as for emulsion 2; the mixture is also milled so as to obtain lipid vesicles with an oily heart, the titanium oxide is incorporated into the fatty phase before the formation of lipid vesicles with oily heart and is therefore encapsulated within these vesicles at the same time. within the internal oily phase, in accordance with the present invention.

Phase A
Sucrose di-stearate 1.35%
Oxyethylenated sorbitan mono-stearate (4 EO) sold under the trade name Tween 61 by ICI 0.9%
Stearic acid 0.75% 2,2,4,4,6,6,8 Heptamethylnonane sold under the trade name Arlamol HD by ICI 15%
TiO 2 sold under the trade name MT-100T by Tayca 10%
Phase B:
Glycerol 3%
Soda (10%) 0.1%
Demineralized water qs 100%
Phase C:
Hydroxyethylcellulose PM 1,300,000 sold under the trade name Natrosol 250HHR by Aqualon 0.5%
Xanthan gum sold under the trade name Keltrol T by Kelco 0.4%
Demineralized water 19%
Conservatives qs
Operating mode ::
Emulsion 3 was prepared according to the following procedure, heating phase A and B at 80 ° C. Then phase B was poured into phase A with stirring with Moritz Turbolab 2100 at a speed of 3500 rpm. leave the mixture stirring for 15 to 30 minutes.

The mixture is then introduced into a Dynomill KDL type ball mill, adjusted for two consecutive passages: the oily-core lipid vesicles are formed in the presence of the pigment.

This phase is then added to the emulsion with stirring with Moritz Turbolab 2100.

This emulsion can be used as it is for the sun protection of the skin.

Emulsion 4: the emulsifying system, according to the invention, comprises a lipophilic surfactant, a hydrophilic surfactant and an amphiphilic lipid: the mixture is ground so as to obtain lipid vesicles with an oily heart; Titanium oxide is incorporated into the fat phase prior to the formation of the oily heart lipid vesicles and is therefore encapsulated within these vesicles within the internal oily phase, in accordance with the present invention.

Phase A:
Sucrose di-stearate 1.35%
Oxyethylenated sorbitan mono-stearate (4 EO) sold under
the trade name Tween 61 by ICI 0.9%
Monosodium salt of N-stearoyl glutamic acid sold under the trade name Acylglutamate HS11 by Ajinomoto 0.75% 2,2,4,4,6,6,8 Heptamethylnonane sold under the trade name Arlamoi HD by ICI 15%
TiO 2 sold under the trade name MT-100T by Tayca 10%
Phase B.

Glycerol 3%
Demineralized water qs 100%
Phase C:
Hydroxyethylcellulose PM 1,300,000 sold under the trade name Natrosol 250HHR by Aqualon 0.5%
Xanthan gum sold under the trade name Keltrol T by Kelco 0.4%
Demineralized water 19%
Conservatives qs
Operating mode:
Emulsion 4 was produced according to the same procedure as for emulsion 3.

This emulsion can be used as it is for the sun protection of the skin.

Evaluation Protocol
For these four emulsions, the photobluing was evaluated according to the protocol according to the compositions were introduced in UV-transparent plastic boxes (crystal polystyrene boxes 50x40x6 cm3) and exposed to
UV (SUNTEST CPS Heraeus) during 1H solar. Colorimetric measurements were made using a Minolta CM1000 colorimeter. A first measurement was taken just before exposure to UV (TO) and a second measurement after one hour of UV exposure (T1 H).

The results are expressed in the system (L, a, b) in which L represents the luminance, a represents the red-green axis (-a = green, + a = red) and b represents the yellow-blue axis ( -b = blue, + b = yellow).

For the evaluation of the photobleuissement, one is interested in the component b, and more precisely in Ab defined by Ab = b T1 H - b TO. The more positive Ab is, the more effective the protection against photobluing.

Results:
The results of the photoblotting test obtained with the four emulsions are described in the following table (I) below:
Table (I)

<tb><SEP> Formula <SEP> Characteristics <SEP> Ab
<tb> Emulsion <SEP> 1 <SEP> System <SEP> emulsifier <SEP> classical <SEP> g <SEP>
<tb> Emulsion <SEP> 2 <SEP> Vesicles <SEP> compliant <SEP> to <SEP> to <SEP> EP-AO <SEP> 641 <SEP> 557 <SEP> - <SEP> 8
<tb><SEP> TiO2 <SEP> to <SEP> outside <SEP> of <SEP> vesicles
<tb> Emulsion <SEP> 3 <SEP> Vesicles <SEP> compliant <SEP> to <SEP> EP-AO <SEP> 641 <SEP> 557 <SEP> - <SEP> 1,2
<tb><SEP> TiO2 <SEP> to <SEP> inside <SEP> of <SEP> vesicles <SEP> according to <SEP> to
<tb><SEP> the invention
<tb> Emulsion <SEP> 4 <SEP> Vesicles <SEP> compliant <SEP> to <SEP> EN <SEP> 94-12005 <SEP> 0.4
<tb><SEP> TiO2 <SEP> to <SEP> inside <SEP> of <SEP> vesicles <SEP> according to <SEP> to
<tb><SEP> the invention
<Tb>
These results clearly show that the introduction of TiO 2 particles inside the lipid vesicles with oily heart makes it possible to very effectively protect the pigment from photobluing. Indeed, the emulsions 3 and 4 in accordance with the invention exhibit a very low photobluing compared with the emulsion 1 which does not form lipid vesicles or with the emulsion 2, the lipid vesicles of which do not encapsulate the titanium.

The Ab of the emulsion 3 was again measured one month after the first measurements. We found: Ab = - 0.4.

This result shows that the photostabilization of the compositions according to the invention is durable.

Emulsions 5 and 6
These emulsions are distinguished from the emulsion 3 by the presence of other pigments such as yellow, brown and black iron oxides at an overall level of 1.9% by weight relative to the total weight of the compositions. These other pigments can be introduced at the same time as the titanium oxide and thus be encapsulated (emulsion 5) or introduced after the formation of the lipid vesicles and therefore be located outside these vesicles (emulsion 6).

These emulsions are tinted creams covering the imperfections of the face and protecting from the sun.

Claims (27)

A dispersion-type composition comprising (i) pigments of at least one metal oxide and (ii) vesicles formed of a lipid membrane surrounding a liquid phase, characterized in that these pigments are encapsulated within said vesicles. 2. Composition according to claim 1, characterized in that said vesicles are oily globules unitarily provided with a monolamellar or oligolamellar liquid crystal coating. 3. Composition according to Claim 2, characterized in that the monolamellar or oligolamellar coating is obtained from at least one lipophilic surfactant, at least one hydrophilic surfactant and at least one fatty acid. and in that it contains a basic agent dissolved in an aqueous phase. 4. Composition according to claim 3, characterized in that the fatty acid comprises at least one saturated fatty chain having more than 12 carbon atoms, preferably from 16 to 22 carbon atoms. 5. Composition according to any one of claims 3 and 4, characterized in that the fatty acid is stearic acid. 6. Composition according to any one of claims 3 to 5, characterized in that the basic agent is selected from the group comprising sodium hydroxide, triethanolamine, lysine and arginine. 7. Composition according to Claim 2, characterized in that the monolamellar or oligolamellar coating is obtained from at least one lipophilic surfactant, at least one hydrophilic surfactant and at least one amphiphilic lipid. ionic composition conferring on the composition a pH ranging from 5.5 to 7.5. 8. Composition according to Claim 7, characterized in that the ionic amphiphilic lipid is chosen from the group comprising neutralized anionic lipids, amphoteric lipids and alkylsulphonic derivatives. 9. Composition according to claim 8, characterized in that the ionic amphiphilic lipid is the monosodium salt of N-stearoyl glutamic acid. 10. Composition according to any one of claims 3 to 9, characterized in that the lipophilic surfactant and the hydrophilic surfactant each comprise at least one saturated fatty chain having more than 12 carbon atoms, preferably from 16 to 22 carbon atoms. 11. Composition according to any one of claims 3 to 10, characterized in that the lipophilic surfactant has an HLB (hydrophilelipophilic balance) ranging from 2 to 5. 12. Composition according to any one of claims 3 to 11, characterized in that the lipophilic surfactant is sucrose distearate. 13. Composition according to any one of claims 3 to 12, characterized in that the hydrophilic surfactant has an HLB ranging from 8 to 12. 14. Composition according to any one of claims 3 to 13, characterized in that the hydrophilic surfactant is polyoxyethylenesorbitan monostearate 4 OE. 15. Composition according to any one of claims 2 to 14, characterized in that the coated oily globules preferably represent from 10 to 40% by weight relative to the total weight of the composition. 16. Composition according to any one of the preceding claims, characterized in that the pigments are nanopigments of metal oxides. 17. Composition according to claim 16, characterized in that the nanopigments consist of primary particles whose average size is chosen from 5 to 100 nm. 18. Composition according to any one of the preceding claims, characterized in that the pigments are pigments of oxides of titanium, iron, zinc, zirconium, or cerium. 19. Composition according to any one of the preceding claims, characterized in that the pigments are coated with alumina and / or aluminum stearate. 20. Composition according to any one of the preceding claims, characterized in that the pigments are preferably titanium oxide nanopigments coated with alumina and aluminum stearate. 21. Composition according to any one of the preceding claims, characterized in that it further contains one or more cosmetically or dermatologically active hydrophilic or lipophilic compounds, free or encapsulated in vesicles. 22. Composition according to any one of the preceding claims, characterized in that it additionally contains a fatty or lipophilic substance chosen from antioxidants, anti-free radicals, moisturizers, melanoregulators, tanning accelerators, depigmenting agents, coloring agents, skin, liporegulators, slimming, anti-acne, antiseborrhoeic, anti aging, anti-wrinkle, anti-UV, keratolytic, anti-inflammatory, refreshing, healing, vascular protective, antibacterial, antifungal, antiperspirant, deodorant, hair conditioner, immunomodulator , nourishing and essential oils and perfumes. 23. Process for the preparation of the compositions defined in any one of the preceding claims, characterized in that it comprises the following steps:  (i) mixing a phase containing pigments with an aqueous phase,  (ii) the mixture obtained is refined after step (i). 24. The method of claim 23, characterized in that the pigments are selected from nanopigments of metal oxides. 25. The method of claim 24, characterized in that the nanopigments of metal oxides are selected from nanopigments of titanium oxides, zinc or cerium. 26. Use of the compositions according to any one of claims 1 to 22 as, or for the manufacture of, cosmetic compositions for the protection of the skin and / or hair. 27. A method of protecting pigments against exposure to light by encapsulating these pigments within vesicles formed of a lipid membrane surrounding a liquid phase.