WO2025097289A1

WO2025097289A1 - Composition for caring for keratin materials

Info

Publication number: WO2025097289A1
Application number: PCT/CN2023/130075
Authority: WO
Inventors: Yu Liu; Qingsheng Tao
Original assignee: LOreal SA
Current assignee: LOreal SA
Priority date: 2023-11-07
Filing date: 2023-11-07
Publication date: 2025-05-15
Anticipated expiration: 2026-05-07
Also published as: FR3154920B3; FR3154920A3

Abstract

Provided is a composition, preferably for caring for keratin materials, comprising: (i) at least one compound of ceramide type; (ii) at least one solid lipid other than compounds of ceramide type; (iii) at least one double-chain nonionic surfactant; and (iv) at least one single-chain nonionic surfactant. Also provided is a non-therapeutic method for caring for keratin materials, comprising applying said composition to the skin.

Description

COMPOSITION FOR CARING FOR KERATIN MATERIALS

TECHNICAL FIELD

The present invention relates to a cosmetic composition. In particular, the present invention relates to a composition for caring for keratin materials. The present invention also relates to a non-therapeutic method for caring for keratin materials.

BACKGROUND ART

Skin acts as a natural barrier between internal and external environments and therefore plays an important role in vital biological functions such as protection against mechanical and chemical injury, micro-organisms, and ultraviolet damage.

Ceramides are the main natural lipids in the stratum corneum, accounting for 50%of total intercellular lipids. When the concentration of ceramides is insufficient, the skin tends to become dry and sensitive. Topical application of ceramides can restore the skin barrier and retain moisture. However, ceramides have high crystallinity and easily to form molecular crystals. Ceramides can be dispersed into water using a surfactant or the like, but it is difficult to sufficiently reduce the particle size thereof (i.e., to obtain higher transparency) , and high dosage of surfactant is required.

As a branch of nanocarrier technology, solid lipid nanoparticles (SLNs) were developed more than 30 years ago. Compared to traditional nano-colloidal systems such as nano-emulsions and liposomes, SLNs were more stable due to its being solid at room temperature. SLN are normally spherical with the diameter of smaller than 500 nm (more preferably<100 nm) . The structure of SLNs is a hydrophobic solid lipid core surrounded by a surfactant layer. The intrinsic properties of SLNs are deeper skin penetration, low toxicity, and high bioavailability.

Compositions containing solid lipid nanoparticles (SLNs) are emerging in the field of cosmetics and dermatology, especially for the encapsulation of hydrophobic cosmetic active ingredients into the lipid core. Some cosmetic actives such as ceramides are insoluble in water. Dissolving them directly into an oil may bring about greasy feeling. Thanks to SLNs, they can be readily introduced into water-based formulae, thereby obtaining homogeneous suspensions.

At present, the typical methods for preparing SLNs include high-speed and high-pressure homogenization, high-frequency sonication, membrane emulsification, which requires high mechanical energy input, high cost and difficult to achieved from the industrial level.

Thus, there is still a need to develop solid lipid nanoparticles comprising ceramides, which can be easily prepared.

SUMMARY OF THE INVENTION

One object of the present application is to provide solid lipid nanoparticles comprising ceramides, which can be easily prepared.

Another object of the present application is to provide a formulation for preparing solid lipid nanoparticles comprising ceramides, which can be easily processed into solid lipid nanoparticles.

The inventors have now discovered that above objects can be achieved by the present invention.

Accordingly, according to a first aspect, the present invention provides a composition, preferably for caring for keratin materials, comprising:

(i) at least one compound of ceramide type;

(ii) at least one solid lipid other than compounds of ceramide type;

(iii) at least one double-chain nonionic surfactant; and

(iv) at least one single-chain nonionic surfactant.

In some embodiments, the composition is a homogeneous mixture. Solid lipid nanoparticles can be easily formed from the homogeneous mixture.

In some embodiments, the composition is in the form of solid lipid nanoparticles. The solid lipid nanoparticles can be easily formed.

In some embodiments, the composition is in the form of suspension of solid lipid nanoparticles in an aqueous phase.

The suspension of the present invention can be used for caring for the skin.

According to a second aspect, the present invention provides a non-therapeutic method for caring for keratin materials, comprising applying the composition according to the first aspect of the present invention to the keratin materials.

Other advantages of the present invention will emerge more clearly on reading the description and the examples that follow.

DETAILED DESCRIPTION OF THE INVENTION

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art the present invention belongs to. When the definition of a term in the present description conflicts with the meaning as commonly understood by those skilled in the art the present invention belongs to, the definition described herein shall apply.

In that which follows and unless otherwise indicated, the limits of a range of values are included within this range, in particular in the expressions "between... and…" and "ranging from... to... " .

Moreover, the expression "at least one" used in the present description is equivalent to the expression "one or more" .

Throughout the instant application, the term “comprising” is to be interpreted as encompassing all specifically mentioned features as well optional, additional, unspecified ones. As used herein, the use of the term “comprising” also discloses the embodiment wherein no features other than the specifically mentioned features are present (i.e. “consisting of” ) .

Unless otherwise specified, all numerical values expressing amount of ingredients and the like which are used in the description and claims are to be understood as being modified by the term "about" . Accordingly, unless indicated to the contrary, the numerical values and parameters described herein are approximate values which are capable of being changed according to the desired purpose as required.

For the purposes of the present invention, the term "keratin materials" is intended to cover human skin, mucous membranes such as the lips, and the hair. Facial skin is most particularly considered according to the present invention.

All percentages in the present invention refer to weight percentage, unless otherwise specified.

According to the first aspect, the composition according to the present invention comprises:

(i) at least one compound of ceramide type;

(ii) at least one solid lipid other than compounds of ceramide type;

(iii) at least one double-chain nonionic surfactant; and

(iv) at least one single-chain nonionic surfactant.

Compounds of ceramide type

According to the first aspect, the composition of the present invention comprises at least one compound of ceramide type.

According to the present invention, the term “compound of ceramide type” is understood to mean natural and/or synthetic ceramides and/or glycoceramides and/or pseudoceramides and/or neoceramides.

Compounds of ceramide type are disclosed, for example, in Patent Applications DE 4424530, DE 4424533, DE 4402929, DE 4420736, WO 95/23807, WO 94/07844, EP-A-0 646 572, WO 95/16665, FR-2 673 179, EP-A-0 227 994, WO 94/07844, WO 94/24097 and WO 94/10131, the teachings of which are included here by way of reference.

The compounds of ceramide type which can be used according to the present invention preferably correspond to the general formula (I) :

in which:

-R₁ denotes:

-either a saturated or unsaturated and linear or branched C₁-C₅₀, preferably C₅-C₅₀, hydrocarbon radical, optionally this radical being substituted by one or more hydroxyl groups optionally esterified by an acid R₇COOH, R₇ being an optionally mono-or polyhydroxylated, saturated or unsaturated and linear or branched C₁-C₃₅ hydrocarbon radical, optionally the hydroxyl or hydroxyls of the R₇ radical being esterified by an optionally mono-or polyhydroxylated, saturated or unsaturated and linear or branched C₁-C₃₅ fatty acid;

-or an R”- (NR-CO) -R’ radical, in which R denotes hydrogen or a mono-or polyhydroxylated, preferably monohydroxylated, C₁-C₂₀ hydrocarbon radical, R’ and R” are each independently hydrocarbon radicals, the sum of the carbon atoms of which is between 9 and 30, R’ being a divalent radical;

-or an R₈-O-CO- (CH₂) _p radical, in which R₈ denotes a C₁-C₂₀ hydrocarbon radical and p is an integer varying from 1 to 12;

-R₂ is chosen from hydrogen, a radical of saccharide type, in particular a (glycosyl) _n, (galactosyl) _m or sulphogalactosyl radical, a sulphate or phosphate residue, a phosphorylethylamine radical and a phosphorylethylammonium radical, in which n is an integer varying from 1 to 4 and m is an integer varying from 1 to 8;

-R₃ denotes hydrogen or a hydroxylated or nonhydroxylated and saturated or unsaturated C₁-C₃₃ hydrocarbon radical, optionally the hydroxyl or hydroxyls being esterified by an inorganic acid or an acid R₇COOH, R₇ having the same meanings as hereinabove, and optionally the hydroxyl or hydroxyls being etherified by a (glycosyl) _n, (galactosyl) _m, sulphogalactosyl, phosphorylethylamine or phosphorylethylammonium radical, n and m having the same meanings as hereinabove, optionally R₃ being substituted by one or more C₁-C₁₄ alkyl radicals; preferably, R₃ denotes a C₁₅-C₂₆α-hydroxyalkyl radical, the hydroxyl group optionally being esterified by a C₁₆-C₃₀α-hydroxy acid;

-R₄ denotes hydrogen, a methyl or ethyl radical, an optionally hydroxylated, saturated or unsaturated and linear or branched C₃-C₅₀ hydrocarbon radical or a-CH₂-CHOH-CH₂-O-R₆ radical, in which R₆ denotes a C₁₀-C₂₆ hydrocarbon radical, or an R₈-O-CO- (CH₂) _p radical, in which R₈ denotes a C₁-C₂₀ hydrocarbon radical and p is an integer varying from 1 to 12;

-R₅ denotes hydrogen or an optionally mono-or polyhydroxylated, saturated or unsaturated and linear or branched C₁-C₃₀ hydrocarbon radical, optionally the hydroxyl or hydroxyls being etherified by a (glycosyl) _n, (galactosyl) _m, sulphogalactosyl, phosphorylethylamine or phosphorylethylammonium radical, in which n is an integer varying from 1 to 4 and m is an integer varying from 1 to 8;

with the proviso that, when R₃ and R₅ denote hydrogen or when R₃ denotes hydrogen and R₅ denotes methyl, then R₄ does not denote hydrogen or a methyl or ethyl radical.

Preference is given, among the compounds of formula (I) , to the ceramides and/or glycoceramides with the structure described by Downing in Journal of Lipid Research, Vol. 35, 2060-2068, 1994, or those disclosed in French Patent Application FR-2 673 179, the teachings of which are included here by way of reference.

The compounds of ceramide type which are more particularly preferred according to the invention are the compounds of formula (I) for which R₁ denotes an optionally hydroxylated and saturated or unsaturated alkyl derived from C₁₄-C₂₂ fatty acids; R₃ denotes an optionally hydroxylated and linear C₁₁-C₁₇ radical and preferably C₁₃-C₁₅ radical, preferably denotes anα-hydroxycetyl radical, and R₂, R₄ and R₅ denote hydrogen.

Preferably, the compound of ceramide type is selected from 2-N-linoleoylamino-octadecane-1, 3-diol; 2-N-oleoylamino-octadecane-1, 3-diol; 2-N-palmitoylamino-octadecane-1, 3-diol; 2-N-stearoylamino-octadecane-1, 3-diol; 2-N-behenoylamino-octadecane-1, 3-diol; 2-N- [2-hydroxy-palmitoyl] -amino-octadecane-1, 3-diol; 2-N-stearoyl amino-octadecane-1, 3, 4-triol and in particular N-stearoyl phytosphingosine, 2-N-palmitoylamino-hexadecane-1, 3-diol, N-linoleoyldihydrosphingosine, N-oleoyldihydrosphingosine, N-palmitoyldihydrosphingosine, N-alpha-hydroxystearoyl-phytosphingosine, N-stearoyldihydrosphingosine, N-behenoyldihydrosphingosine, N-docosanoyl N-methyl-D-glucamine, cetyl acid N- (2-hydroxyethyl) -N- (3-cetyloxy-2-hydroxypropyl) amide and bis- (N-hydroxyethyl N-cetyl) malonamide; and mixtures thereof.

Most preferably, the ceramide may be selected from N-alpha-hydroxystearoyl-phytosphingosine (also called ceramide AP) , sold, for example, as DS-CERAMIDE AP by Solus Advanced Materials, N-stearoyl phytosphingosine (also called ceramide NP) , sold, for example, as DS-CERAMIDE Y3S by Solus Advanced Materials Co., Ltd., and mixtures thereof.

Advantageously, the compound of ceramide type is present in the composition of the present invention in an amount ranging from 0.01 wt. %to 0.5 wt. %, preferably from 0.02 wt. %to 0.3 wt. %, more preferably from 0.05 wt. %to 0.25 wt. %, relative to the total weight of the composition.

Solid lipids

According to the first aspect, the composition of the present invention comprises at least one solid lipid other than compounds of ceramide type.

As used herein, "solid lipid" means that the lipid is solid at room temperature (25℃) and atmospheric pressure (1.013 X10⁵Pa) . The melting point is above 25℃, preferably above 45℃.

Solid lipid other than compounds of ceramide type can be selected from solid fatty acids, solid fatty alcohols, waxes, mono-, di-or triglycerides, and mixtures thereof.

Advantageously, the solid fatty acids comprise 12-24 carbons with one carboxyl group, preferably the solid fatty acid is selected from lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid and mixtures thereof, more preferably the solid fatty acid is selected from myristic acid, palmitic acid, stearic acid, and mixtures thereof.

Advantageously, the solid fatty alcohols comprise 12-24 carbons with one hydroxyl group, preferably the solid fatty alcohol is selected from cetyl alcohol, stearyl alcohol, cetearyl alcohol, myristyl alcohol, lauryl alcohol, tridecyl alcohol, pentadecyl alcohol, hexadecyl alcohol, arachidyl alcohol, behenyl alcohol, and mixtures thereof, more preferably the solid fatty alcohol is selected from cetyl alcohol, stearyl alcohol, cetearyl alcohol, and mixtures thereof.

Advantageously, the waxes are waxes of animal, vegetable, mineral origin, non-silicone synthetic waxes and mixtures thereof, preferably the wax is selected from hydrocarbon waxes, such as beeswax, lanolin wax, and Chinese insect waxes; rice bran wax, Carnauba wax, Candellila wax, Ouricury wax, Alfa wax, Berry wax, Shellac wax, Japanese wax and sumac wax; Montan wax, orange and lemon waxes, microcrystalline waxes, paraffins and ozokerite, and mixtures thereof.

Advantageously, the mono-, di-or triglycerides is selected from esters of saturated or unsaturated, linear, or branched fatty acid including 10 to 22 carbon atoms, preferably, the mono-, di-or triglyceride is selected from mono-, di-or triglycerides of one or more of lauric acid, oleic acid, stearic acid, isostearic acid, capric acid, caprylic acid, and myristic acid.

Preferably, the solid lipid other than compounds of ceramide type is selected from candelilla wax, beeswax, shea butter, glyceryl mono-/di-/tri-stearate, and mixtures thereof.

Advantageously, the solid lipid other than compounds of ceramide type is present in the composition of the present invention in an amount ranging from 1 wt. %to 20 wt. %, preferably from 2 wt. %to 15 wt. %, more preferably from 3 wt. %to 10 wt. %, relative to the total weight of the composition.

Advantageously, the weight ratio of the solid lipid other than compounds of ceramide type to the compound of ceramide type is from 20 to 5000, preferably from 20 to 3000, more preferably from 20 to 2000, even more preferably from 20 to 1000, most preferably from 30 to 500.

Double-chain non-ionic surfactants

According to the first aspect, composition of the present invention comprises at least one double-chain non-ionic surfactant.

The double-chain non-ionic surfactant is different from solid lipids mentioned above.

Preferably, the double-chain non-ionic surfactant is selected from diesters of one or more saturated or unsaturated, linear or branched fatty acids including 8 to 22, preferably 10 to 18 carbon atoms and polyglycerin with a polyglyceryl moiety derived from 2 to 10 glycerol units.

As examples of saturated or unsaturated, linear or branched fatty acids including 8 to 22 carbon atoms, mention can be made of lauric acid, oleic acid, stearic acid, isostearic acid, capric acid, caprylic acid, and myristic acid.

More preferably, the double-chain non-ionic surfactant is selected from PG2 dicaprate, PG2 dicaprylate, PG2 dilaurate, PG2 dimyristate, PG2 distearate, PG2 diisostearate, PG2 dioleate, PG3 dicaprate, PG3 dicaprylate, PG3 dilaurate, PG3 dimyristate, PG3 distearate, PG3 diisostearate, PG3 dioleate, PG4 dicaprate, PG4 dicaprylate, PG4 dilaurate, PG4 dimyristate, PG4 distearate, PG4 diisostearate, PG4 dioleate, PG5 dicaprate, PG5 dicaprylate, PG5 dilaurate, PG5 dimyristate, PG5 distearate, PG5 diisostearate, PG5 dioleate, PG6 dicaprate, PG6 dicaprylate, PG6 dilaurate, PG6 dimyristate, PG6 distearate, PG6 diisostearate, PG6 dioleate, PG7 dicaprate, PG7 dicaprylate, PG7 dilaurate, PG7 dimyristate, PG7 distearate, PG7 diisostearate, PG7 dioleate, PG8 dicaprate, PG8 dicaprylate, PG8 dilaurate, PG8 dimyristate, PG8 distearate, PG8 diisostearate, PG8 dioleate, PG9 dicaprate, PG9 dicaprylate, PG9 dilaurate, PG9 dimyristate, PG9 distearate, PG9 diisostearate, PG9 dioleate, PG10 dicaprate, PG10 dicaprylate, PG10 dilaurate, PG10 dimyristate, PG10 distearate, PG10 diisostearate, PG10 dioleate, and mixtures thereof.

Even more preferably, the double-chain non-ionic surfactant is selected from polyglyceryl dioleate, polyglyceryl distearate, and mixtures thereof.

The double-chain non-ionic surfactant can be derived from renewable source.

Advantageously, the double-chain non-ionic surfactant is present in the composition of the present invention in an amount ranging from 0.1 wt. %to 10 wt. %, preferably from 0.5 wt. %to 8 wt. %, more preferably from 1 wt. %to 6 wt. %, relative to the total weight of the composition.

Single-chain non-ionic surfactants

According to the first aspect, composition of the present invention comprises at least one single-chain non-ionic surfactant.

The single-chain non-ionic surfactant is different from solid lipids mentioned above.

Preferably, the single-chain non-ionic surfactant is selected from monoesters of one or more saturated or unsaturated, linear or branched fatty acids including 8 to 22, preferably 10 to 18 carbon atoms and polyglycerin with a polyglyceryl moiety derived from 2 to 10 glycerol units.

More preferably, the single-chain non-ionic surfactant is selected from PG2 caprate, PG2 caprylate, PG2 laurate, PG2 myristate, PG2 stearate, PG2 isostearate, PG2 oleate, PG3 caprate, PG3 caprylate, PG3 laurate, PG3 myristate, PG3 stearate, PG3 isostearate, PG3 oleate, PG4 caprate, PG4 caprylate, PG4 laurate, PG4 myristate, PG4 stearate, PG4 isostearate, PG4 oleate, PG5 caprate, PG5 caprylate, PG5 laurate, PG5 myristate, PG5 stearate, PG5 isostearate, PG5 oleate, PG6 caprate, PG6 caprylate, PG6 laurate, PG6 myristate, PG6 stearate, PG6 isostearate, PG6 oleate, PG7 caprate, PG7 caprylate, PG7 laurate, PG7 myristate, PG7 stearate, PG7 isostearate, PG7 oleate, PG8 caprate, PG8 caprylate, PG8 laurate, PG8 myristate, PG8 stearate, PG8 isostearate, PG8 oleate, PG9 caprate, PG9 caprylate, PG9 laurate, PG9 myristate, PG9 stearate, PG9 isostearate, PG9 oleate, PG10 caprate, PG10 caprylate, PG10 laurate, PG10 myristate, PG10 stearate, PG10 isostearate, PG10 oleate, and mixtures thereof.

The single-chain non-ionic surfactant can be derived from renewable source.

Even more preferably, the single-chain non-ionic surfactant is selected from polyglyceryl laurate, polyglyceryl myristate, polyglyceryl stearate, and mixtures thereof.

Advantageously, the single-chain non-ionic surfactant is present in the composition of the present invention in an amount ranging from 0.1 wt. %to 10 wt. %, preferably from 0.5 wt. %to 8 wt. %, more preferably from 1 wt. %to 6 wt. %, relative to the total weight of the composition.

Advantageously, the ratio of the total weight of the double-chain nonionic surfactant and the single-chain nonionic surfactant to the weight of the solid lipid is from 0.2 to 20, preferably from 0.3 to 15, more preferably from 0.4 to 10, most preferably from 0.5 to 5.

Aqueous phase

The composition of the present invention may comprise a continuous aqueous phase.

Said aqueous phase comprises water.

Advantageously, said aqueous phase is present in an amount ranging from 20 wt. %to 99 wt. %, preferably from 30 wt. %to 99 wt. %, and more preferably from 50 wt. %to 99 wt. %of the total weight of the composition.

Additional cosmetic active ingredients

The composition of the present invention may comprise an additional cosmetic active ingredient in addition to the compound of ceramide type.

As examples of cosmetic active ingredient, mention can be made of natural extracts; vitamins such as vitamin A (retinol) , vitamin E (tocopherol) , vitamin C (ascorbic acid) , vitamin B5 (panthenol) , vitamin B3 (niacinamide) , and derivatives of said vitamins (in particular esters) and mixtures thereof; urea; caffeine; salicylic acid and derivatives thereof; alpha-hydroxy acids such as lactic acid or glycolic acid and derivatives thereof; sunscreens; extracts from algae, fungi, plants, yeasts and bacteria; enzymes; agents acting on the microcirculation, and so on.

It is easy for the skilled in the art to adjust the amount of the additional cosmetic active ingredient based on the final use of the composition according to the present invention.

Additional adjuvants or additives

The composition of the present invention may also contain conventional cosmetic adjuvants or additives, for instance fragrances, chelating agents, preserving agents and bactericides, thickeners, pH regulators, fillers and mixtures thereof.

The skilled in the art can select the amount of the additional adjuvants or additive so as not to adversely impact the final use of the composition according to the present invention.

According to a particularly preferred embodiment, the present invention provides a composition for caring for keratin materials comprising, relative to the total weight of the composition:

(i) from 0.05 wt. %to 0.25 wt. %of a compound selected from N-alpha-hydroxystearoyl-phytosphingosine, N-stearoyl phytosphingosine, and mixtures thereof;

(ii) from 3 wt. %to 10 wt. %of at least one solid lipid selected from candelilla wax, beeswax, shea butter, glyceryl mono-/di-/tri-stearate, and mixtures thereof;

(iii) from 1 wt. %to 6 wt. %of at least one double-chain nonionic surfactant selected from polyglyceryl dioleate, polyglyceryl distearate, and mixtures thereof; and

(iv) from 1 wt. %to 6 wt. %of at least one single-chain nonionic surfactant selected from polyglyceryl laurate, polyglyceryl myristate, polyglyceryl stearate, and mixtures thereof.

Galenic form and method

In some embodiments, the composition is a homogeneous mixture, from which solid lipid nanoparticles can be easily formed by spontaneous emulsification without involving vigorous mechanical energy input, for example high-speed and high-pressure homogenization, sonication, or membrane emulsification.

In some embodiments, the composition is in the form of solid lipid nanoparticles. The solid lipid nanoparticles can be easily formed and the macroscopic crystallization of compounds of ceramide type can be effectively suppressed.

In some embodiments, the composition is in the form of suspension of solid lipid nanoparticles in an aqueous phase. The suspension can be easily formed and the macroscopic crystallization of compounds of ceramide type can be effectively suppressed.

Preferably, the composition of the present invention is in the form of a translucent or semi-translucent suspension of solid lipid nanoparticles in aqueous phase.

When the particle size of nanoparticle is from 110 to 150 nm, then the composition is considered semi-translucent; and when the particle size of nanoparticle is less than 110 nm, then the composition is considered translucent. When the particle size of nanoparticle is greater than 500 nm., then the composition is considered creamy.

The composition of the present invention can be in the form of lotion, cream, serum, etc.

The composition of the present invention can be used as shampoos, hair coloring products, and hair conditions, skincare products, etc.

Thus, the composition of the present invention can be used for caring for keratin materials.

According to the second aspect, the present invention provides a non-therapeutic method for caring for keratin materials, comprising applying the composition according to the first aspect of the present invention to the keratin materials.

EXAMPLES

The following examples serve to illustrate the present invention without, however, being limiting in nature.

Main raw materials used, trade names and supplier thereof are listed in Table 1.

Table 1

Invention examples 1-5 and comparative examples 1-3

Compositions of invention examples (IE. ) 1-5 and comparative examples (CE. ) 1-3 in the form of suspension were prepared according to the amounts given in Table 2. The amount of each component is given in%by weight of the total weight of the composition containing it.

Table 2

Polyglyceryl dioleate-10 (and) tocopherol comprises 99.95 wt. %of Polyglyceryl dioleate-10 and 0.05 wt. %tocopherol.

Compositions of invention examples 1-5 are compositions according to the present invention.

Composition of comparative example 1 does not comprise at least one single-chain nonionic surfactant.

Composition of comparative example 2 does not comprise at least one double-chain nonionic surfactant.

Composition of comparative example 3 does not comprise at least one solid lipid other than compounds of ceramide type.

Preparation process:

The compositions listed above were prepared as follows, taking the composition of invention example 1 as an example:

1) mixing solid lipids (Euphorbia cerifera (candelilla) wax) , surfactants (Polyglyceryl dioleate-10 (and) tocopherol, Polyglyceryl-10 laurate) and ceramide (Ceramide NP) at a temperature between 90 ℃ until a homogeneous, oil phase was obtained;

2) heating water to a temperature between 90 ℃;

3) adding the oil phase obtained in step 1) into water with stirring for about 10 minutes to obtain a suspension;

4) cooling the obtained suspension rapidly to room temperature.

Evaluation

Each suspension of invention examples 1-5 and comparative examples 1-3 was evaluated in terms of particle size and stability.

The sizes of particles in suspensions of invention examples (IE. ) 1-5 and comparative examples (CE. ) 1-3 were determined using a Brookhaven dynamic light scattering (DLS) equipment. Each sample was tested in triplicate. The particle sizes of fresh samples and samples stored for 2 months at 4℃, room temperature (20-25℃) and 45℃, respectively were measured to monitor the stability.

The main experimental parameters for the DLS experiments were listed in Table 3.

Table 3

Table 4 shows effective diameter and polydispersity index (PDI) of each suspension of invention examples 1-5 and comparative examples 1-3 after 2 months storage.

Table 4

Effective diameter: average diameter.

The term "unmeasurable" means samples are too turbid/cloudy to be measured due to too many large particles.

The smaller the effective diameter, the higher transparency the suspension has. When the effective diameter is less than 110 nm, the appearance of the suspension is translusent. When the effective diameter is between 110 nm and 500 nm, the appearance of the suspension is semi-translusent.

The smaller the PDI, the better for stability.

If the effective diameter of a sample stored for a time period is smaller than 500 nm without formation of large aggregates on the vessel wall, then the sample was regarded as ‘stable’ , otherwise, the sample was regarded as "unstable" .

Table 5 shows the stability of each suspension of invention examples 1-5.

Table 5

Table 6 shows the stability of each suspension of comparative examples 1-3.

Table 6

It can be seen from Tables 4-6 that suspension of invention examples 1-5 have translucent or semi-transluent appearance and is stable for at least 2 months, while suspensions of comparative examples 1-3 are not stable.

Claims

A composition, preferably for caring for keratin materials, comprising:

(i) at least one compound of ceramide type;

(ii) at least one solid lipid other than compounds of ceramide type;

(iii) at least one double-chain nonionic surfactant; and

(iv) at least one single-chain nonionic surfactant.
Composition according to claim 1, wherein the compound of ceramide type corresponds to the general formula (I) :

in which:

- R₁ denotes:

- either a saturated or unsaturated and linear or branched C₁-C₅₀, preferably C₅-C₅₀, hydrocarbon radical, optionally this radical being substituted by one or more hydroxyl groups optionally esterified by an acid R₇COOH, R₇ being an optionally mono-or polyhydroxylated, saturated or unsaturated and linear or branched C₁-C₃₅ hydrocarbon radical, optionally the hydroxyl or hydroxyls of the R₇ radical being esterified by an optionally mono-or polyhydroxylated, saturated or unsaturated and linear or branched C₁-C₃₅ fatty acid;

- or an R”- (NR-CO) -R’ radical, in which R denotes hydrogen or a mono-or polyhydroxylated, preferably monohydroxylated, C₁-C₂₀ hydrocarbon radical, R’ and R” are each independently hydrocarbon radicals, the sum of the carbon atoms of which is between 9 and 30, R' being a divalent radical;

- or an R₈-O-CO- (CH₂) _p radical, in which R₈ denotes a C₁-C₂₀ hydrocarbon radical and p is an integer varying from 1 to 12;

- R₂ is chosen from hydrogen, a radical of saccharide type, in particular a (glycosyl) _n, (galactosyl) _m or sulphogalactosyl radical, a sulphate or phosphate residue, a phosphorylethylamine radical and a phosphorylethylammonium radical, in which n is an integer varying from 1 to 4 and m is an integer varying from 1 to 8;

- R₃ denotes hydrogen or a hydroxylated or nonhydroxylated and saturated or unsaturated C₁-C₃₃ hydrocarbon radical, optionally the hydroxyl or hydroxyls being esterified by an inorganic acid or an acid R₇COOH, R₇ having the same meanings as hereinabove, and optionally the hydroxyl or hydroxyls being etherified by a (glycosyl) _n, (galactosyl) _m, sulphogalactosyl, phosphorylethylamine or phosphorylethylammonium radical, n and m having the same meanings as hereinabove, optionally R₃ being substituted by one or more C₁-C₁₄ alkyl radicals; preferably, R₃ denotes a C₁₅-C₂₆α-hydroxyalkyl radical, the hydroxyl group optionally being esterified by a C₁₆-C₃₀α-hydroxy acid;

- R₄ denotes hydrogen, a methyl or ethyl radical, an optionally hydroxylated, saturated or unsaturated and linear or branched C₃-C₅₀ hydrocarbon radical or a-CH₂-CHOH-CH₂-O-R₆ radical, in which R₆ denotes a C₁₀-C₂₆ hydrocarbon radical, or an R₈-O-CO- (CH₂) _p radical, in which R₈ denotes a C₁-C₂₀ hydrocarbon radical and p is an integer varying from 1 to 12;

- R₅ denotes hydrogen or an optionally mono-or polyhydroxylated, saturated or unsaturated and linear or branched C₁-C₃₀ hydrocarbon radical, optionally the hydroxyl or hydroxyls being etherified by a (glycosyl) _n, (galactosyl) _m, sulphogalactosyl, phosphorylethylamine or phosphorylethylammonium radical;

with the proviso that, when R₃ and R₅ denote hydrogen or when R₃ denotes hydrogen and R₅ denotes methyl, then R₄ does not denote hydrogen or a methyl or ethyl radical.
Composition of claim 1 or 2, wherein the compound of ceramide type is selected from 2-N-linoleoylamino-octadecane-1, 3-diol; 2-N-oleoylamino-octadecane-1, 3-diol; 2-N-palmitoylamino-octadecane-1, 3-diol; 2-N-stearoylamino-octadecane-1, 3-diol; 2-N-behenoylamino-octadecane-1, 3-diol; 2-N- [2-hydroxy-palmitoyl] -amino-octadecane-1, 3-diol; 2-N-stearoyl amino-octadecane-1, 3, 4-triol, 2-N-palmitoylamino-hexadecane-1, 3-diol, N-linoleoyldihydrosphingosine, N-oleoyldihydrosphingosine, N-palmitoyldihydrosphingosine, N-alpha-hydroxystearoyl-phytosphingosine, N-stearoyldihydrosphingosine, N-behenoyldihydrosphingosine, N-docosanoyl N-methyl-D-glucamine, cetyl acid N- (2-hydroxyethyl) -N- (3-cetyloxy-2-hydroxypropyl) amide and bis- (N-hydroxyethyl N-cetyl) malonamide; and mixtures thereof; preferably, the compound of ceramide type is selected from N-alpha-hydroxystearoyl-phytosphingosine, N-stearoyl phytosphingosine, and mixtures thereof.
Composition of any one of claims 1 to 3, wherein the compound of ceramide type is present in an amount ranging from 0.01 wt. %to 0.5 wt. %, preferably from 0.02 wt. %to 0.3 wt. %, more preferably from 0.05 wt. %to 0.25 wt. %, relative to the total weight of the composition.
Composition according to any of claims 1 to 4, wherein the solid lipid other than compounds of ceramide type is selected from solid fatty acids, solid fatty alcohols, waxes, mono-, di-or triglycerides, and mixtures thereof.
Cosmetic composition according to claim 5, wherein

the solid fatty acids comprise 12-24 carbons with one carboxyl group, preferably the solid fatty acid is selected from lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid and mixtures thereof, more preferably the solid fatty acid is selected from myristic acid, palmitic acid, stearic acid, and mixtures thereof;

the solid fatty alcohols comprise 12-24 carbons with one hydroxyl group, preferably the solid fatty alcohol is selected from cetyl alcohol, stearyl alcohol, cetearyl alcohol, myristyl alcohol, lauryl alcohol, tridecyl alcohol, pentadecyl alcohol, hexadecyl alcohol, arachidyl alcohol, behenyl alcohol, and mixtures thereof, more preferably the solid fatty alcohol is selected from cetyl alcohol, stearyl alcohol, cetearyl alcohol, and mixtures thereof;

the waxes are waxes of animal, vegetable, mineral origin, non-silicone synthetic waxes and mixtures thereof, preferably the wax is selected from hydrocarbon waxes, rice bran wax, Carnauba wax, Candellila wax, Ouricury wax, Alfa wax, Berry wax, Shellac wax, Japanese wax and sumac wax; Montan wax, orange and lemon waxes, microcrystalline waxes, paraffins and ozokerite, and mixtures thereof;

the mono-, di-or triglycerides is selected from mono-, di-or triglycerides of one or moer saturated or unsaturated, linear, or branched fatty acids including 10 to 22 carbon atoms, preferably, the mono-, di-or triglyceride is selected from mono-, di-or triglycerides of one or more of lauric acid, oleic acid, stearic acid, isostearic acid, capric acid, caprylic acid, and myristic acid.
Composition of any one of claims 1 to 6, wherein the solid lipid other than compounds of ceramide type is present in an amount ranging from 1 wt. %to 20 wt. %, preferably from 2 wt. %to 15 wt. %, more preferably from 3 wt. %to 10 wt. %, relative to the total weight of the composition, preferably, the weight ratio of the solid lipid to the compound of ceramide type is from 20 to 5000, preferably from 20 to 3000, more preferably from 20 to 2000, even more preferably from 20 to 1000, most preferably from 30 to 500.
Composition of any one of claims 1 to 7, wherein the double-chain non-ionic surfactant is selected from diesters of one or more saturated or unsaturated, linear or branched fatty acids including 8 to 22, preferably 10 to 18 carbon atoms and polyglycerin with a polyglyceryl moiety derived from 2 to 10 glycerol units.
Composition according to any of claims 1 to 8, wherein the double-chain non-ionic surfactant is present in an amount ranging from 0.1 wt. %to 10 wt. %, preferably from 0.5 wt. %to8 wt. %, more preferably from 1 wt. %to 6 wt. %, relative to the total weight of the composition.
Composition according to any of claims 1-9, wherein the single-chain non-ionic surfactant is selected from diesters of one or more saturated or unsaturated, linear or branched fatty acids including 8 to 22, preferably 10 to 18 carbon atoms and polyglycerin with a polyglyceryl moiety derived from 2 to 10 glycerol units.
Composition according to any of claims 1-10, wherein the single-chain non-ionic surfactant is present an amount ranging from 0.1 wt. %to 10 wt. %, preferably from 0.5 wt. %to 8 wt. %, more preferably from 1 wt. %to 6 wt. %, relative to the total weight of the composition, preferably, the ratio of the total weight of the double-chain nonionic surfactant and the single-chain nonionic surfactant to the weight of the solid lipid is from 0.2 to 20, preferably from 0.3 to 15, more preferably from 0.4 to 10, most preferably from 0.5 to 5.
Composition according claim 1, comprising, relative to the total weight of the composition:

(i) from 0.05 wt. %to 0.25 wt. %of a compound selected from N-alpha-hydroxystearoyl-phytosphingosine, N-stearoyl phytosphingosine, and mixtures thereof;

(ii) from 3 wt. %to 10 wt. %of at least one solid lipid selected from candelilla wax, beeswax, shea butter, glyceryl mono-/di-/tri-stearate, and mixtures thereof;

(iii) from 1 wt. %to 6 wt. %of at least one double-chain nonionic surfactant selected from polyglyceryl dioleate, polyglyceryl distearate, and mixtures thereof; and

(iv) from 1 wt. %to 6 wt. %of at least one single-chain nonionic surfactant selected from polyglyceryl laurate, polyglyceryl myristate, polyglyceryl stearate, and mixtures thereof.
Composition according any of claims 1-12, further comprises a continuous aqueous phase.
Composition according claim 13, which is in the form of suspension.
A non-therapeutic method for caring for keratin materials, comprising applying the composition according to any of claims 1 to 14 to the keratin materials.