FR3115992A1 - Composition in the form of an emulsion comprising saponins and a vegetable oil - Google Patents

Abstract

Composition in the form of an emulsion comprising saponins and a vegetable oil The present invention relates to a cosmetic composition in the form of an oil-in-water emulsion, comprising: an aqueous phase, saponins present in a content less than or equal to 1% by weight relative to the total weight of composition, andat least 10% by weight relative to the total weight of composition of at least one vegetable oil, said vegetable oil comprising a total oleic acid content of between 18% and 28% by weight and a total linoleic acid content of between 45% and 68% by weight relative to the total weight of oil. Figure for the abstract: none

Description

Composition in the form of an emulsion comprising saponins and a vegetable oil

The present invention relates to a composition in the form of an oil-in-water emulsion, as well as a cosmetic process for applying such a composition to keratin materials.

Saponins are molecules naturally produced in particular by plants, which have surfactant properties. They have a foaming power, and can be used in cosmetics, in particular for preparing cleaning compositions or emulsifying compositions.

However, these molecules are formulated in small quantities, in particular for tolerance issues, i.e. less than 1% by weight relative to the total weight of the composition, which is relatively low to allow stable emulsification of the composition without addition of co- surfactant.

There is therefore a need for cosmetic compositions comprising saponins, in particular in small quantities, which are stable without addition of co-surfactant.

The present invention makes it possible to meet this expectation. The Applicant has in fact demonstrated that the introduction of a specific vegetable oil into a composition comprising a small quantity of saponins makes it possible to obtain a stable system without the addition of co-surfactant.

The subject of the present invention is therefore a cosmetic composition in the form of an oil-in-water emulsion, comprising:

• an aqueous phase,
• saponins present in a content less than or equal to 1% by weight relative to the total weight of composition, and
• at least 10% by weight relative to the total composition weight of at least one vegetable oil, said vegetable oil comprising a total oleic acid content of between 18% and 35% by weight and a total linoleic acid content of between 45 % and 68% by weight relative to the total weight of oil.

A subject of the present invention is also a cosmetic process for caring for keratin materials, preferably the skin, comprising the application to said keratin materials of a composition according to the invention.

A subject of the present invention is also the use of a cosmetic composition according to the invention for moisturizing keratin materials, preferably the skin.

By “keratinous materials”, is meant the skin or the superficial body growths.

Saponins

The composition according to the invention comprises saponins. Saponins (also called saponosides) are molecules naturally produced, in particular by plants, which are complex glycosides; they comprise an aglycone unit linked to one or more sugar chains. The aglycone unit can consist of a sterol or a triterpene, to give a steroid saponin or a triterpenoid saponin respectively.

The saponins according to the invention are preferably of plant origin. They are preferably present in a plant extract. Preferably, they are extracted from soap tree (Sapindus mukurossi, Sapindus trifoliatus), quinoa (Chenopodium quinoa), liquorice (Glycyrrhiza glabra), horse chestnut (Aesculus hippocastanum), bacoppa (Baccopa monneria), sarsaparilla (Smilax medica , Smilax aspera, Smilax ornata), Panama wood (Quillaja saponaria), Soapwort (Saponaria officinalis), Ginseng (Panax ginseng), Yucca (Yucca schidigera), Maltese cross (Tribulus terrestris), Jujube (Zizyphus joazeiro), Jiaogulan ( Gynostemma pentaphyllum), Indian asparagus (Asparagus racemosus), alfalfa (Medicago sativa) or mixtures thereof.

More preferably, the saponins according to the invention are extracted from soap tree (Sapindus mukurossi, Sapindus trifoliatus) or quinoa (Chenopodium quinoa).

A commercially available soap tree (Sapindus mukurossi) extract is the product SAPONIN I marketed by HANGZHOU SANTRUE BIOTECHNOLOGY CO., LTD. This extract comprises 60% to 70% by weight of saponins relative to the total weight of extract.

A commercially available quinoa extract (Chenopodium quinoa seed extract) is the product MEXORYL SCK marketed by NOVEAL. This extract comprises more than 45% by weight of saponins relative to the total weight of extract.

The saponins are present in the composition according to the invention in a content less than or equal to 1% by weight relative to the total weight of the composition. Preferably, the saponins are present in a content of at least 0.1% by weight relative to the total weight of composition.

Preferably, the saponins are present in a content ranging from 0.3% to 0.9% by weight relative to the total weight of the composition, preferably from 0.3% to 0.6% by weight.

Preferably, when the composition comprises a plant extract comprising saponins, this extract is present in a content of between 0.3% and 1% by weight relative to the total weight of the composition, preferably between 0.5% and 0, 95% by weight.

Vegetable oil

The composition according to the invention comprises at least one vegetable oil comprising a total oleic acid content of between 18% and 28% by weight relative to the total weight of oil, and a total linoleic acid content of between 45% and 68 % by weight relative to the total weight of oil.

In addition, this vegetable oil is present in the composition according to the invention in a content of at least 10% by weight relative to the total weight of the composition.

The vegetable oil according to the invention has a specific profile; it contains :

• oleic acid in an amount between 18% and 35% by weight relative to the total weight of oil, and
• linoleic acid in an amount between 45% and 68% by weight relative to the total weight of oil.

As vegetable oil, mention may in particular be made of sunflower oil, soybean oil, corn oil and mixtures thereof.

Preferably, the vegetable oil is sunflower oil or soybean oil, more preferably sunflower oil.

Preferably, the vegetable oil is present in a content ranging from 10% to 50% by weight relative to the total weight of the composition, preferably from 12% to 40% by weight, preferably from 15% to 30% by weight.

Aqueous phase

The composition according to the invention comprises a physiologically acceptable aqueous medium. By “physiologically acceptable”, is meant a medium compatible with keratin materials.

The composition according to the invention preferably comprises an aqueous medium comprising water and optionally an organic solvent soluble in water at 25° C., chosen for example from polyols and alkanols, linear or branched, C2-C4 , such as ethanol and isopropanol, propanol, butanol and mixtures thereof.

By polyol according to the invention is meant a hydrocarbon chain comprising at least 2 carbon atoms, preferably from 2 to 50 carbon atoms, preferably from 4 to 20 carbon atoms, preferably having from 2 to 10 carbon atoms. carbon, and preferably having from 2 to 6 carbon atoms, and carrying at least two hydroxy groups. The polyols used in the present invention may have a weight-average molecular mass of less than or equal to 1000, preferably between 90 and 500.

The polyol can be chosen from glycerin, diglycerin, polyglycerin, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, pentylene glycol, hexylene glycol, 1,3-propanediol, 1, 5-pentanediol, octane 1,2-diol, polyethylene glycols, especially having 5 to 50 ethylene oxide groups, and sugars such as sorbitol, and mixtures thereof. More particularly the polyol is glycerine.

The aqueous phase of the composition according to the invention preferably comprises water, at least one polyol and at least one linear C2-C4 alkanol.

The composition generally comprises from 10% to 90% by weight of water relative to the total weight of the composition, preferably from 20% to 80% by weight.

The amount of polyol(s) can range from 2% to 40% by weight relative to the total weight of the composition, preferably ranging from 3% to 30% by weight, and preferably ranging from 4% to 20% by weight.

The amount of organic solvent(s) can range, for example, from 0.5% to 30% by weight, preferably from 1% to 20% by weight, better still from 2% to 10% by weight relative to the total weight of the composition.

Hydrophilic thickening polymer

Preferably, the composition of the invention comprises at least one hydrophilic thickening polymer.

The composition according to the invention may comprise at least one hydrophilic or water-soluble thickening polymer, chosen in particular from:

- natural polymers such as cellulose derivatives such as carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxymethylcellulose, hydroxypropylmethylcellulose, ethylhydroxyethylcellulose, xanthan gum, locust bean gum, scleroglucan gum, gellan, rhamsane gums, alginates, karaya gum, modified starches, modified or unmodified guar gums and their derivatives such as hydroxypropylguar, or hyaluronic acid salts such as sodium hyaluronate,

- hydrophilic clays. By hydrophilic clay is meant a clay capable of swelling in water; this clay swells in water and forms a colloidal dispersion after hydration. As hydrophilic clay, mention may be made of smectites such as saponites, hectorites, montmorillonites, bentonites, beidellite. Mention may be made of synthetic hectorites (also called laponites) such as the products sold by the company Laporte under the name Laponite XLG, Laponite RD, Laponite RDS (these products are sodium and magnesium silicates and in particular sodium silicates, lithium and magnesium); bentonites such as the product sold under the name Bentone HC by the company RHEOX; magnesium and aluminum silicates, in particular hydrated, such as the products sold by the company Vanderbilt Company under the name Veegum ultra, Veegum HS, Veegum DGT, or even calcium silicates and in particular that in synthetic form sold by the company under the name of Micro-cel C,

- homo- or copolymers of acrylic or methacrylic acids or their salts and their esters and in particular the products sold under the names VERSICOL F® or VERSICOL K® by the company ALLIED COLLOID, UTRAHOLD 8® by the company CIBA-GEIGY, or polyacrylic acids of the SYNTHALEN K type,

- copolymers of acrylic acid and acrylamide sold in the form of their sodium salt under the names RETEN® by the company HERCULES, the sodium salts of polyhydroxycarboxylic acids sold under the name HYDAGEN F® by the company HENKEL,

- poly(meth)acrylic acid/alkyl acrylate copolymers of the PEMULEN TR-1 or PEMULEN TR-2 type from BF Goodrich, or else Carbopol ETD-2020, Carbopol ETD-1382, Carbopol ETD-1342,

- homopolymers and copolymers based on acrylamido propanesulfonic acid (AMPS®, Lubrizol monomer), such as for example:

• polyacrylamidomethyl propane sulphonic acid partially neutralized with ammonia and highly crosslinked, marketed in particular by the company CLARIANT, for example under the name HOSTACERIN AMPS®;
• acrylamidomethyl propane sulfonic acid/acrylamide copolymers, for example of the SEPIGEL or SIMULGEL type marketed in particular by the company SEPPIC,
• copolymers of acrylamidomethyl propane sulfonic acid/polyoxyethylenated alkyl methacrylates (cross-linked or not) among others of the ARISTOFLEX HMS, ARISTOFLEX TAC type, marketed by the company CLARIANT,
• copolymers of acrylamidomethyl propane sulfonic acid and hydroxyethyl acrylate, such as for example the acrylamidomethyl propane sulfonic acid/hydroxyethyl acrylate copolymer such as in particular that used in the commercial product sold under the name SIMULGEL NS by the company SEPPIC, or else the copolymer acrylamidomethyl propane sulphonic acid/hydroxyethyl acrylate such as in particular that used in the commercial product sold under the name SEPINOV EMT 10 marketed by the company SEPPIC (INCI name: HYDROXYETHYL ACRYLATE/SODIUM ACRYLOYLDIMETHYL TAURATE COPOLYMER);

- associative polymers and in particular associative polyurethanes such as the C ₁₆ -OE ₁₂₀ -C ₁₆ polymer from the company ELEMENTIS (marketed under the name RHEOLATE FX1100, molecule with a urethane function and average molecular weight by weight of 1300), EO being an oxyethylenated unit, Rheolate 205 with a urea function sold by the company RHEOX or else Rheolate 208 or 204 (these polymers being sold in pure form) or DW 1206B from RHOM & HAAS with a C20 alkyl chain and urethane bond, sold at 20% active ingredient in water. It is also possible to use solutions or dispersions of these associative polyurethanes, in particular in water or in an aqueous-alcoholic medium. By way of example of such polymers, mention may be made of RHEOLATE FX1010, RHEOLATE FX1035 and RHEOLATE 1070, Rheolate 255, Rheolate 278 20 and Rheolate 244 sold by the company ELEMENTIS. You can also use the product DW 1206F and DW 1206J, as well as Acrysol RM 184 or Acrysol 44 from RHOM & HAAS, or even Borchigel LVV 44 from BORCHERS,

- and mixtures thereof.

Preferably, the composition according to the invention comprises at least one hydrophilic or water-soluble thickening polymer chosen from natural polymers, more preferably from xanthan gum, scleroglucan gum and mixtures thereof.

Preferably, the hydrophilic thickening polymer, alone or as a mixture, is present in amounts of active material ranging from 0.01% to 12% by weight, more preferably from 0.05% to 7% by weight, even more preferably from 0.1% to 5% by weight relative to the total weight of the composition.

Co-surfactant

The composition of the invention may comprise at least one co-surfactant (also called co-emulsifier).

Preferably, the composition of the invention is substantially free of co-surfactant. By "substantially free", it is meant that the composition comprises less than 3% by weight, preferably less than 2% by weight, preferably less than 1% by weight, preferably less than 0.5% by weight, preferably less than 0.1% by weight relative to the total weight of composition, of co-surfactant.

Preferably, the composition of the invention is completely free of co-surfactant.

By co-surfactant is meant any amphiphilic compound capable of emulsifying a liquid fatty phase phase comprising a vegetable oil in an aqueous phase, having an HLB value (hydrophilic/lipophilic balance) of between 3 and 15, preferably of approximately 5. Such a co-surfactant is in particular polyglyceryl-2 stearate (having an HLB of 5).

The composition according to the invention can also comprise any additive usually used in cosmetics, such as in particular fillers, preservatives, UV filters, coloring materials and/or active agents.

Finally, the invention also relates to a cosmetic process for caring for keratin materials, preferably the skin, comprising the application to said keratin materials of a composition according to the invention.

The invention also relates to the use of a cosmetic composition according to the invention for moisturizing keratin materials, preferably the skin.

Concrete, but in no way limiting, examples illustrating the invention will now be given.

In the examples, the temperature is ambient (20° C.) and expressed in degrees Celsius unless otherwise indicated, and the pressure is atmospheric pressure, unless otherwise indicated.

In the examples, the amounts of the ingredients of the compositions are given in % by weight relative to the total weight of the composition (% w/w).

Examples of formulations according to the invention (F1 to F4) and comparisons (F5* to F7*) and evaluation of their properties

The formulations F1 to F4 according to the invention, and the comparative formulations F5* to F7* (marked by a star), are detailed in the tables below.

Indeed, the comparative formulas include virgin olive oil (F5*), refined olive oil (F6*) or refined coconut oil (F7*).

These oils have the following oleic acid and linoleic acid contents:

• virgin olive oil: from 55% to 83% by weight of oleic acid and from 3.5% to 21% by weight of linoleic acid relative to the total weight of oil;
• refined olive oil: from 55% to 83% by weight of oleic acid and from 3.5% to 21% by weight of linoleic acid relative to the total weight of oil; And
• coconut oil: from 6% to 9% by weight of oleic acid and about 2% by weight of linoleic acid relative to the total weight of oil.

They are prepared by the following protocol:

Phase B1 preparation: pre-dispersion under a deflocculating machine of the saponins or quinoa extract in a little water until a homogeneous, clear, light brown mixture is obtained.

Aqueous phase preparation A: water and glycerin are mixed, then xanthan gum and scleroglucan gum are added to obtain gelation.

Stir until a smooth homogeneous gel is obtained under a deflocculator (speed of 1200 to 1500 revolutions) or under a turbine and central and scraping blades (turbine speed 3000 rpm & blades 50 rpm), for a period of approximately 15 minutes.

Phase B1 is added then simultaneously phase B2 (mixture of oil and tocopherol) in phase A with stirring (speed of 3300 rpm under turbine, or turbine speed 4000 rpm & blades 50 rpm), to obtain emulsification, for a period about 15 minutes.

A smooth homogeneous off-white flexible emulsion is thus obtained. It is checked under a microscope that the carpet is regular, homogeneous and fairly thin.

At a temperature below 28°C, phase C (pre-dispersion of alcohol and salicylic acid) is added, for about 8 minutes, with stirring (speed of 3300 revolutions under turbine, or turbine speed 4000rpm & blades 50rpm ).

We check the macroscopic appearance of the emulsion, and under the microscope that the carpet is regular, homogeneous and fairly thin.

Adjust if necessary (with pure arginine), for about 5 minutes, with stirring (speed of 3300 rpm under turbine, or turbine speed 4000 rpm & blades 50 rpm).

We check the macroscopic appearance of the emulsion, and under the microscope that the carpet is regular, homogeneous and fairly thin.

Phase Chemical Name F1
(% w/w) AT WATER Qsp 100 AT GLYCERIN 7 VS SALICYLIC ACID 0.2 AT L-ARGININE 0.2 AT xanthan gum 0.5 AT PURIFIED SCLEROGLUCANE (D-GLUCOPYRANOSE) GUM 0.25 B1 Water 10 B 1 Soap tree extract
(SAPINDUS EXTRACT POWDER)
(SAPONIN I from HANGZHOU SANTRUE BIOTECHNOLOGY) 0.8 B 2 REFINED SUNFLOWER OIL
(HELIANTHUS ANNUUS (SUNFLOWER) SEED OIL) 20 B2 TOCOPHEROL 0.1 VS Ethanol 5

Phase Chemical Name F2
(% w/w) F3
(% w/w) F4
(% w/w) F5*
(% w/w) AT WATER Qsp 100 Qsp 100 Qsp 100 Qsp 100 AT GLYCERIN 5 7 5 5 VS SALICYLIC ACID 0.2 0.2 0.2 0.2 AT Blend of xanthan and scleroglucan gum 1 - 1 1 AT PURIFIED SCLEROGLUCANE (D-GLUCOPYRANOSE) GUM - 0.25 - - AT xanthan gum - 0.5 - - B1 Water 10 10 10 10 B1 quinoa extract
(Chenopodium quinoa seed extract)
(MEXORYL SCK from NOVEAL) 1 1 1 1 B2 REFINED SUNFLOWER OIL
(HELIANTHUS ANNUUS (SUNFLOWER) SEED OIL) 20 10 - - B2 REFINED SOYBEAN OIL - - 20 - B2 VIRGIN OLIVE OIL - - - 20 B2 TOCOPHEROL 0.1 0.1 0.1 0.1 VS Ethanol 5 5 5 5 AT L-arginine - 0.15 - -

Phase Chemical Name F2
(% w/w) F6*
(% w/w) F7*
(% w/w) AT WATER Qsp 100 Qsp 100 Qsp 100 AT GLYCERIN 5 5 5 VS SALICYLIC ACID 0.2 0.2 0.2 AT Blend of xanthan and scleroglucan gum 1 1 1 B1 Water 10 10 10 B1 quinoa extract
(Chenopodium quinoa seed extract)
(MEXORYL SCK from NOVEAL) 1 1 1 B2 REFINED SUNFLOWER OIL (HELIANTHUS ANNUUS (SUNFLOWER) SEED OIL) 20 - - B2 REFINED OLIVE OIL - 20 - B2 REFINED COCONUT OIL - - 20 B2 TOCOPHEROL 0.1 0.1 0.1 VS Ethanol 5 5 5

These formulations are evaluated for their different properties, according to the protocols below:

pH measurement:

The pH is measured at 25°C.

Express the result with one decimal.

It is measured on D1 at AT (room temperature) then at 2 months of stability at AT and 45°C.

The results are shown in Table 4 below.

Centrifuge:

24 hours after formulation, centrifugation is carried out on a 37 g sample for 1 hour at a constant speed of 900 g (equivalent to approximately 2,200 rpm).

The centrifugation test is a projection of the stability of a product and allows to study if the system is cohesive.

After centrifugation of the sample, the presence or absence of settling and phase separation phenomena is determined.

Viscosity:

It is measured at 25°C on a rheometer. Several mobiles can be used depending on the viscosity of the juice.

The mobile must be adapted to the texture of the juice. The viscosity value must be between 10 and 90 UD, if this is not the case then the spindle must be changed.

Here the mobile used is mobile M2.

Measurement in UD: unit of deviation, with a standard deviation ± 5 UD if viscosity < 50UD and +/- 7 UD if viscosity > 50UD.

Express the result as an integer.

Accelerated aging studies:

Thermal oven :

A sample of each formulated mixture is placed at different temperatures for 2 months: at 4°C, at 45°C, at 55°C, at 37°C and at room temperature (RT, 25°C).

During the two months of stabilization, several analyzes are carried out for each of the criteria.

Cyclic oven :

A formulated sample is placed in a cyclic oven in which, for 10 days, it undergoes 10 temperature cycles varying from -20°C to +20°C. The principle of a cycle is as follows: 6 hours at +20°C, then 6 hours of descent to -20°C, then 6 hours at -20°C, and finally 6 hours of ascent to +20°C. This makes it possible to study the resistance capacity of a mixture in the face of extreme random thermal cycles.

The results are shown in the following table:

Formula F1 F2 F3 F4 F5* F6* F7* pH 25°/D1 4.9 4.7 4.5 4.7 4.6 4.6 4.7 pH stability over time at TA & 45°
(T=2 months vs D1) OK OK OK OK OK OK OK Viscosity
(M2, DU) 50 68 40 66 57 66 56 Viscosity stability (mobile M2 for 10 minutes over time
(=T2 month vs D1)) OK OK AVERAGE AVERAGE OK AVERAGE No centrifugation OK OK OK OK Acceptable OK OK Stability 55°C,
1 week OK Acceptable Acceptable No
compliant No
compliant Improper Acceptable Stability 45°C,
2 months OK Acceptable Acceptable Compliant No
compliant Acceptable Improper TA stability,
2 months OK Acceptable OK OK No
compliant Acceptable Improper 1 year stability RAS RAS RAS Slight release on the surface
Matt surface Release ++ in the holes
heterogeneous texture
Matt surface Release in the holes
heterogeneous texture
Matt surface Release + in the holes
heterogeneous texture
Matt surface

The results show that only the formulas according to the invention F1 to F4 are stable at different temperatures. In particular, the best results are obtained with sunflower oil (formulas F1 to F3).

On the contrary, the comparative formulas F5* to F7* are not stable and exhibit a release and a heterogeneous texture.

Claims (15)

Cosmetic composition in the form of an oil-in-water emulsion, comprising:
an aqueous phase,
saponins present in a content less than or equal to 1% by weight relative to the total weight of composition, and
at least 10% by weight relative to the total composition weight of at least one vegetable oil, said vegetable oil comprising a total oleic acid content of between 18% and 35% by weight and a total linoleic acid content of between 45 % and 68% by weight relative to the total weight of oil. Cosmetic composition according to Claim 1, in which the saponins are present in a plant extract. Cosmetic composition according to one of the preceding claims, in which the saponins are extracted from soap tree, quinoa, liquorice, horse chestnut, bacoppa, sarsaparilla, Panama wood, soapwort, ginseng , yucca, malted cross, jujube, jiaogulan, Indian asparagus, alfalfa or their mixtures, preferably extracted from soap tree or quinoa. Cosmetic composition according to one of the preceding claims, in which the saponins are present in a content ranging from 0.3% to 0.9% by weight relative to the total weight of the composition, preferably from 0.3% to 0 .6% by weight. Cosmetic composition according to one of the preceding claims, in which the vegetable oil is chosen from sunflower oil, soya oil, corn oil and mixtures thereof, preferably sunflower oil. Cosmetic composition according to one of the preceding claims, in which the vegetable oil is present in a content ranging from 10% to 50% by weight relative to the total weight of the composition, preferably from 12% to 40% by weight, preferably from 15% to 30% by weight. Cosmetic composition according to one of the preceding claims, in which the aqueous phase comprises water and optionally an organic solvent soluble in water at 25°C, chosen for example from polyols and alkanols, linear or branched, in C2-C4, such as ethanol and isopropanol, propanol, butanol and mixtures thereof. Cosmetic composition according to one of the preceding claims, which comprises at least one organic solvent, in an amount ranging from 0.5% to 30% by weight, preferably from 1% to 20% by weight, better still from 2% to 10% by weight relative to the total weight of the composition. Cosmetic composition according to one of the preceding claims, which additionally comprises a hydrophilic thickening polymer. Cosmetic composition according to Claim 9, in which the hydrophilic thickening polymer is chosen from natural polymers, hydrophilic clays, homo- or copolymers of acrylic or methacrylic acids or their salts and their esters, copolymers of acrylic acid and acrylamide in the form of their sodium salt, copolymers of poly(meth)acrylic acid/alkyl acrylate, homopolymers and copolymers based on acrylamido propanesulfonic acid, associative polymers in particular associative polyurethanes, and mixtures thereof; preferably, the hydrophilic thickening polymer is chosen from natural polymers, more preferably from xanthan gum, scleroglucan gum and mixtures thereof. Cosmetic composition according to Claim 9 or 10, in which the hydrophilic thickening polymer is present in amounts of active material ranging from 0.01% to 12% by weight, more preferably from 0.05% to 7% by weight, even more preferably from 0.1% to 5% by weight relative to the total weight of the composition. Cosmetic composition according to one of the preceding claims, which additionally comprises at least one co-surfactant. Cosmetic composition according to one of Claims 1 to 11, which is substantially free of co-surfactant, preferably which is completely free of co-surfactant. Cosmetic process for caring for keratin materials, preferably the skin, comprising the application to said keratin materials of a composition according to one of the preceding claims. Use of a cosmetic composition according to one of Claims 1 to 13, for moisturizing keratin materials, preferably the skin.