WO2023004621A1

WO2023004621A1 - Composition in the form of emulsion with a lamellar structure

Info

Publication number: WO2023004621A1
Application number: PCT/CN2021/108904
Authority: WO
Inventors: Fan Wang
Original assignee: LOreal SA
Current assignee: LOreal SA
Priority date: 2021-07-28
Filing date: 2021-07-28
Publication date: 2023-02-02
Anticipated expiration: 2024-01-28
Also published as: FR3125709A1; FR3125709B1; CN117677370A

Abstract

A composition in the form of an oil-in-water emulsion for caring for and/or making up keratin materials, comprising: (i) at least one fatty alcohol with a carbon-chain length of 12-18; (ii) at least one surfactant, and (iii) at least one solubilizing agent, wherein the solubility of the fatty alcohol in the solubilizing agent is not less than 5 g/100 g the solubilizing agent.

Description

COMPOSITION IN THE FORM OF EMULSION WITH A LAMELLAR STRUCTURE

TECHNICAL FIELD

The present invention relates to a composition in the form of emulsion. In particular, the present invention relates to a composition in the form of emulsion with a lamellar structure.

BACKGROUND ART

Oil-in-water (O/W) or water-in-oil (W/O) emulsions are well known in the field of cosmetics and dermatology, in particular for the preparation of cosmetic products, such as milks, creams, tonics, serums or toilet waters.

It is known practice, in the cosmetics or dermatological field, to use oil-in-water (O/W) emulsions. These emulsions, that consist of an oil phase (or lipophilic phase) dispersed in an aqueous phase, have an external aqueous phase and are therefore products that are more pleasant to use because of the feeling of freshness that they provide.

Compositions which have a lamellar structure or a lamellar phase are also well known in the field of cosmetics and dermatology. For example JP-A-2006-249011 and JP-A-2009-298748 disclose cosmetic compositions with a lamellar structure with specific surfactants to form the amphiphilic bilayers.

Compositions with a lamellar structure or a lamellar have a characteristic optical birefringence under 90° cross-polarized light due to light interference by the lamellar structure or lamellar phase. Thus, the aesthetic aspect caused by the optical effects of the compositions with a lamellar structure or a lamellar phase can be in particular useful for cosmetic applications.

Many known methods for making multi-lamellar emulsions, especially those for encapsulation of oil-soluble active ingredients require heating above 45℃ or complex process (such as, for multi-step multi-phase systems) , rapid cooling, or high pressure.

For example, US9949900B2 discloses a liquid crystal emulsion including intercellular lipids, the preparation thereof requires heating and rapid cooling.

US6908625B2 discloses a process comprising encapsulating retinol into surfactant vesicles using cholesterol and cholesterol esters, followed by making sphingosome, then making lamellar liquid-crystals emulsions. The system obtained shows increased active stability after one-month storage at 45℃. However, it requires multiple processing steps and requires heating up to 90℃.

Some cosmetic active ingredients such as ferulic acid and Beta-carotene are insoluble in water, soluble in an oil and sensitive to water, heat and/or oxygen.

At present, atypical method for introducing heat-sensitive active ingredients into a cream comprises preparing an emulsion base and then dispersing the cosmetic active ingredients to the pre-made base. In most cases, preparation of the base requires heating upon emulsification, and the cosmetic active ingredients can be added only after the base is cooled, so as to avoid the degradation of the cosmetic active ingredients.

Thus, there is still a need for a system the preparation process therefor does not comprise heating to a relatively high temperature, for example above 45℃.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a system in the form of emulsion with a lamellar structure, the preparation process therefor does not comprise heating to a relatively high temperature, for example above 45℃.

Another object of the present invention is to provide a cosmetic composition in the form of emulsion with a lamellar structure, the preparation process therefor does not comprise heating to a relatively high temperature, for example above 45℃.

Still another object of the present invention is to provide a non-therapeutic method for caring for and/or making up keratin materials.

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

Specifically, the inventors have discovered that it is possible to formulate compositions in the form of emulsion with a lamellar structure, the preparation process therefor does not comprise heating to a relatively high temperature, for example above 45 ℃.

Accordingly, in a first aspect, the present invention provides a composition in the form of an oil-in-water emulsion for caring for and/or making up keratin materials, comprising:

(i) at least one fatty alcohol with a carbon-chain length of 12-18;

(ii) at least one surfactant, and

(iii) at least one solubilizing agent, wherein the solubility of the fatty alcohol in the solubilizing agent is not less than 5 g/100 g the solubilizing agent.

The composition of the present invention is in the form of an oil-in-water emulsion. Thus, said composition comprises a continuous aqueous phase and a dispersed fatty phase.

The inventors found that the composition of the present invention can be emulsified at room temperature below 45℃ and has a lamellar structure or a lamellar structured-phase, so that oil-soluble or oil dispersible cosmetic active ingredients can be dispersed homogeneously in the oily phase without being heated during the preparation of the composition, therefore, the stability of the oil-soluble or oil dispersible cosmetic active ingredient is improved. Oil droplets are also encapsulated within the multi-lamellar interface embedded in a network of lamellar structured continuous phase.

In a second aspect, the present invention provides a non-therapeutic method for caring for and/or making up 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.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations of the present invention will now be described, by way of example only, with reference to the attached figure, wherein:

Fig. 1 shows polarized light microscopy image of the composition obtained in invention example 1, wherein, 1’ represents an oil phase, 2’ represents interfaces, and 3’ represents the lamellar continuous phase.

Fig. 2 shows polarized light microscopy image of the composition obtained in invention example 5, wherein, 1 representsβ-carotene, 2 represents interfaces, and 3 represents the lamellar continuous phase.

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 "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. 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 present invention provides a composition in the form of an oil-in-water emulsion for caring for and/or making up keratin materials, comprising:

(i) at least one fatty alcohol with a carbon-chain length of 12-18;

(ii) at least one surfactant, and

Aqueous phase

As an oil-in-water emulsion, the cosmetic composition of the present invention comprises a continuous aqueous phase.

Said aqueous phase comprises water.

Preferably, the continuous aqueous phase comprises an organic solvent miscible with water (at room temperature 25℃) such as glycol having from 2 to 20 carbon atoms, preferably from 2 to 10 carbon atoms, and preferentially having from 2 to 6 carbon atoms, such as pentylene glycol, hexylene glycol, caprylyl glycol, 1, 3-propanediol, diethylene glycol; and mixtures thereof.

Advantageously, said aqueous phase is present in an amount ranging from 40%to 95%by weight, preferably from 50%to 90%by weight, and more preferably from 55%to 85%by weight of the total weight of the composition.

Advantageously, water is present in the composition of the present invention in an amount ranging from 40%to 95%by weight, preferably from 45%to 90%by weight, relative to the total weight of the composition.

Oily phase

As an oil-in-water emulsion, the composition of the present invention comprises at least one dispersed oily phase.

Said oily phase comprises at least one oil.

The oil can be volatile or non-volatile.

The term “oil” means a water-immiscible non-aqueous compound that is liquid at room temperature (25℃) and at atmospheric pressure (760 mmHg) . The term “non-volatile oil” means an oil that may remain on keratin materials at room temperature and atmospheric pressure for at least several hours and that especially has a vapour pressure of less than 10 ^-3 mmHg (0.13 Pa) . Anon-volatile oil may also be defined as having an evaporation rate such that, under the conditions defined previously, the amount evaporated after 30 minutes is less than 0.07 mg/cm ².

These oils may be of plant, mineral or synthetic origin.

Said oil can be selected from hydrocarbon oils, silicone oils, and fluorinated oils.

The term “hydrocarbon oil” means an oil formed essentially from, or even constituted by, carbon and hydrogen atoms, and optionally O and N atoms, and free of Si and F heteroatoms. Such oil can contain alcohol, ester, ether, carboxylic acid, amine and/or amide groups.

The term “silicone oil” means an oil containing at least one silicon atom, especially containing Si-O groups.

The term “fluorinated oil” means an oil containing at least one fluorine atom.

Preferably, the oil is selected from hydrocarbon oils.

More preferably, the oil is selected from polar hydrocarbon oils such as ester oils, for example, isopropyl myristate, isopropyl palmitate, ethyl hexyl palmitate, triglycerides, isopropyl lauroyl sarcosinate.

As examples of triglycerides, mention can be made of triglycerides of fatty acids containing from 6 to 22 carbon atoms, more preferably from 8 to 18 carbon atoms, such as caprylic/capric triglycerides, ricinus communis (castor) oil, cocos nucifera (coconut) oil, simmondsia chinensis seed oil, linum usitatissimum (linseed) oil, persea gratissima (avocado) oil, macadamia ternifolia seed oil, limnanthes alba (meadowfoam) seed oil, olea europaea (olive) fruit oil, canola oil, prunus amygdalus dulcis (sweet almond) oil, elaeis guneenaeis guineensis (palm) oil, punica granatum seed oil, helianthus annuus (sunflower) seed oil, glycine soja (soybean) oil, zea mays (corn) germ oil, carthamus tinctorius (safflower) seed oil, sesamum indicum (sesame) seed oil, oryza sativa (rice) bran oil, and bertholletia excels seed oil.

The oil can be, for example, present in the composition according to the present invention in an amount ranging from 1%to 50%by weight, preferably from 2%to 30%by weight, relative to the total weight of the composition.

Fatty alcohols

According to the first aspect, the composition according to the present invention comprises at least one fatty alcohol with a carbon-chain length of 12-18.

Preferably, the fatty alcohol has a carbon-chain length of 12-16.

For the purposes of the invention, the fatty alcohol is linear.

The fatty alcohol suitable for use in the invention is preferably selected from lauryl alcohol, tridecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetyl alcohol, oleyl alcohol, stearyl alcohol, cetearyl alcohol, and mixtures thereof; and preferably selected from lauryl aocohol, myristyl alcohol, cetyl alcohol, and mixtures thereof.

As commercial products of lauryl alcohol, mention may be made, for example, of the product sold under the name MAGNOL-1216MB by the company MAGNAKRON.

As commercial products of myristyl alcohol, mention may be made, for example, of the product sold under the name

14 by the company BASF.

As commercial products of cetyl alcohol, mention may be made, for example, of the products sold under the names

16/98 F and

16/98 P sold by the company Ecogreen Oleochemicals,

16 sold by the company Evonik Goldschmidt,

16 sold by the company Cognis,

1698 sold by the company VVF,

1698 P sold by the company Oxiteno, Cetyl Alcohol 98%Min sold by the company Emery Oleochemicals,

16 (98%) sold by the company Godrej Industries,

16-98 sold by the company Sasol,

6098 sold by the company Kao, and

16 sold by the company Aegis Chemical.

Advantageously, the fatty alcohol is present in the composition according to the present invention in an amount ranging from 0.5 wt. %to 25 wt. %, preferably from 1 wt. %to 10 wt. %, relative to the total weight of the composition.

Surfactants

According to the first aspect, the composition of the present invention comprises at least one surfactant.

The surfactant is not particularly limited and it can be selected from anionic surfactants, amphoteric surfactants, nonionic surfactants, and cationic surfactants. Preferably, the surfactant is selected from anionic surfactants and nonionic surfactants.

Anionic surfactants

The term "anionic surfactant" means a surfactant comprising, as ionic or ionizable groups, only anionic groups.

In the present description, aspecies is termed as being "anionic" when it bears at least one permanent negative charge or when it can be ionized as a negatively charged species, under the conditions of use of the composition of the invention (for example the medium or the pH) and not comprising any cationic charge.

The anionic surfactants may be sulfate, sulfonate and/or carboxylic (or carboxylate) surfactants. Needless to say, amixture of these surfactants may be used.

It is understood in the present description that:

- carboxylate anionic surfactants comprise at least one carboxylic or carboxylate function (-COOH or-COO ^-) and may optionally also comprise one or more sulfate and/or sulfonate functions;

- the sulfonate anionic surfactants comprise at least one sulfonate function (-SO ₃H or-SO ₃ ^–) and may optionally also comprise one or more sulfate functions, but do not comprise any carboxylate functions; and

- the sulfate anionic surfactants comprise at least one sulfate function but do not comprise any carboxylate or sulfonate functions.

The carboxylic anionic surfactants that may be used thus comprise at least one carboxylic or carboxylate function (-COOH or-COO ^-) .

They may be chosen from the following compounds: acylglycinates, acyllactylates, acylsarcosinates, acylglutamates; alkyl-D-galactosideuronic acids, carboxylates such as stearates; alkyl ether carboxylic acids, alkyl (C6-30 aryl) ether carboxylic acids, alkylamido ether carboxylic acids; and also the salts of these compounds;

the alkyl and/or acyl groups of these compounds comprising from 6 to 30 carbon atoms, especially from 12 to 28, better still from 14 to 24 or even from 14 to 18 carbon atoms; the aryl group preferably denoting a phenyl or benzyl group;

these compounds possibly being polyoxyalkylenated, especially polyoxyethylenated, and then preferably comprising from 1 to 50 ethylene oxide units and better still from 2 to 10 ethylene oxide units.

Use may also be made of the C6-C24 alkyl monoesters of polyglycoside-polycarboxylic acids, such as C6-C24 alkyl polyglycoside-citrates, C6-C24 alkyl polyglycoside-tartrates and C6-C24 alkyl polyglycoside-sulfosuccinates, and salts thereof.

Among the above carboxylic surfactants, mention may be made most particularly of polyoxyalkylenated alkyl (amido) ether carboxylic acids and salts thereof, in particular those comprising from 2 to 50 alkylene oxide and in particular ethylene oxide groups, such as the compounds sold by the company Kao under the name Akypo,

The polyoxyalkylenated alkyl (amido) ether carboxylic acids that may be used are preferably chosen from those of formula (1) :

R ₁- (OC ₂H ₄) _n-OCH ₂COOA (1)

in which:

- R1 represents a linear or branched C6-C24 alkyl or alkenyl radical, an alkyl (C8-C9) phenyl radical, a radical R2CONH-CH2-CH2-with R2 denoting a linear or branched C9-C21 alkyl or alkenyl radical,

preferably, R1 is a C8-C20 and preferably C8-C18 alkyl radical, and aryl preferably denotes phenyl,

- n is an integer or decimal number (average value) ranging from 2 to 24 and preferably from 2 to 10,

- A denotes H, ammonium, Na, K, Li, Mg or a monoethanolamine or triethanolamine residue.

It is also possible to use mixtures of compounds of formula (1) , in particular mixtures of compounds containing different groups R1.

The polyoxyalkylenated alkyl (amido) ether carboxylic acids that are particularly preferred are those of formula (1) in which:

- R1 denotes a C12-C14 alkyl, cocoyl, oleyl, nonylphenyl or octylphenyl radical,

- A denotes a hydrogen or sodium atom, and

- n varies from 2 to 20 and preferably from 2 to 10.

Even more preferentially, use is made of compounds of formula (1) in which R denotes a C12 alkyl radical, A denotes a hydrogen or sodium atom and n ranges from 2 to 10.

Preferentially, the carboxylic anionic surfactants are chosen, alone or as a mixture, from:

- acylglutamates, especially of C6-C24 or even C12-C20, such as stearoylglutamates, and in particular disodium stearoylglutamate, sodium stearoylglutamate;

- acylsarcosinates, especially of C6-C24 or even C12-C20, such as palmitoylsarcosinates, and in particular sodium palmitoylsarcosinate;

- acyllactylates, especially of C12-C28 or even C14-C24, such as behenoyllactylates, and in particular sodium behenoyllactylate;

- C6-C24 and especially C12-C20 acylglycinates;

- (C6-C24) alkyl ether carboxylates and especially (C12-C20) alkyl ether carboxylates;

- polyoxyalkylenated (C ₆-C ₂₄) alkyl (amido) ether carboxylic acids, in particular those comprisingfrom 2 to 50 ethylene oxide groups;

in particular in the form of alkali metal or alkaline-earth metal, ammonium or amino alcohol salts.

The sulfonate anionic surfactants that may be used comprise at least one sulfonate function (-SO ₃H or-SO ₃ ^–) .

They may be chosen from the following compounds: alkylsulfonates, alkylamidesulfonates, alkylarylsulfonates, α-olefinsulfonates, paraffin sulfonates, alkylsulfosuccinates, alkyl ether sulfosuccinates, alkylamidesulfosuccinates, alkylsulfoacetates, N-acyltaurates, acylisethionates; alkylsulfolaurates; and also the salts of these compounds;

the alkyl groups of these compounds comprising from 6 to 30 carbon atoms, especially from 12 to 28, better still from 14 to 24 or even from 14 to 18 carbon atoms; the aryl group preferably denoting a phenyl or benzyl group;

Preferentially, the sulfonate anionic surfactants are chosen, alone or as a mixture, from:

- C6-C24 and especially C12-C20 acyltaurates, especially sodium methyl stearoyl taurate;

- C6-C24 and especially C12-C20 alkylsulfosuccinates, especially laurylsulfosuccinates;

- C6-C24 and especially C12-C20 alkyl ether sulfosuccinates;

- (C6-C24) acylisethionates and preferably (C12-C18) acylisethionates,

The sulfate anionic surfactants that may be used comprise at least one sulfate function (-OSO ₃H or-OSO ₃ ^-) .

They may be chosen from the following compounds: alkyl sulfates, alkyl ether sulfates, alkylamido ether sulfates, alkylaryl polyether sulfates, monoglyceride sulfates; and also the salts of these compounds;

Preferentially, the sulfate anionic surfactants are chosen, alone or as a mixture, from:

- alkyl sulfates, especially of C6-C24 or even C12-C20,

- alkyl ether sulfates, especially of C6-C24 or even C12-C20, preferably comprising from 2 to 20 ethylene oxide units;

When the anionic surfactant is in salt form, the said salt may be chosen from alkali metal salts, such as the sodium or potassium salt, ammonium salts, amine salts and in particular amino alcohol salts, and alkaline-earth metal salts, such as the magnesium salt.

Examples of amino alcohol salts that may be mentioned include monoethanolamine, diethanolamine and triethanolamine salts, monoisopropanolamine, diisopropanolamine or triisopropanolamine salts, 2-amino-2-methyl-1-propanol salts, 2-amino-2-methyl-1, 3-propanediol salts and tris (hydroxymethyl) aminomethane salts.

Alkali metal or alkaline-earth metal salts and in particular the sodium or magnesium salts are preferably used.

Preferentially, the anionic surfactants are chosen, alone or as a mixture, from:

- C6-C24 and especially C12-C20 alkyl sulfates;

- C6-C24 and especially C12-C20 alkyl ether sulfates; preferably comprising from 2 to 20 ethylene oxide units;

-C6-C24 and especially C12-C20 alkylsulfosuccinates, especially laurylsulfosuccinates;

- C6-C24 and especially C12-C20 alkyl ether sulfosuccinates;

- (C6-C24) acylisethionates and preferably (C12-C18) acylisethionates;

- C6-C24 and especially C12-C20 acylsarcosinates; especially palmitoylsarcosinates;

- (C6-C24) alkyl ether carboxylates, preferably (C12-C20) alkyl ether carboxylates;

- polyoxyalkylenated (C6-C24) alkyl (amido) ether carboxylic acids and salts thereof, in particular those comprising from 2 to 50 alkylene oxide and in particular ethylene oxide groups;

- C6-C24 and especially C12-C20 acyltaurates;

- C6-C24 and especially C12-C20 acylglutamates;

- C12-C20 carboxylates;

- C6-C24 and especially C12-C20 acylglycinates;

Nonionic surfactants

They may be chosen from alcohols, α-diols and (C _1-20) alkylphenols, these compounds being polyethoxylated and/or polypropoxylated and/or polyglycerolated, the number of ethylene oxide and/or propylene oxide groups possibly ranging from 1 to 100, and the number of glycerol groups possibly ranging from 2 to 30; or alternatively these compounds comprising at least one fatty chain comprising from 8 to 30 carbon atoms and especially from 16 to 30 carbon atoms.

Mention may also be made of condensates of ethylene oxide and of propylene oxide with fatty alcohols; polyethoxylated fatty amides preferably having from 2 to 30 ethylene oxide units, polyglycerolated fatty amides comprising on average from 1 to 5, and in particular from 1.5 to 4, glycerol groups; polyethoxylated fatty acid esters of sorbitan preferably containing from 2 to 40 ethylene oxide units, fatty acid esters of sucrose, polyoxyalkylenated and preferably polyoxyethylenated fatty acid esters containing from 2 to 150 mol of ethylene oxide, including oxyethylenated plant oils, N-(C6-24 alkyl) glucamine derivatives, amine oxides such as (C10-14 alkyl) amine oxides or N-(C10-14 acyl) aminopropylmorpholine oxides.

Mention may also be made of nonionic surfactants of alkyl (poly) glycoside type, represented especially by the following general formula:

R ₁O- (R ₂O) _t- (G) _v

in which:

- R ₁ represents a linear or branched alkyl or alkenyl radical comprising 6 to 24 carbon atoms and especially 8 to 18 carbon atoms, or an alkylphenyl radical whose linear or branched alkyl radical comprises 6 to 24 carbon atoms and especially 8 to 18 carbon atoms;

- R ₂ represents an alkylene radical comprising 2 to 4 carbon atoms,

- G represents a sugar unit comprising 5 to 6 carbon atoms,

- t denotes a value ranging from 0 to 10 and preferably 0 to 4,

- v denotes a value ranging from 1 to 15 and preferably 1 to 4.

Preferably, the alkylpolyglycoside surfactants are compounds of the formula described above in which:

- R ₁ denotes a linear or branched, saturated or unsaturated alkyl radical comprising from 8 to 18 carbon atoms,

- R ₂ represents an alkylene radical comprising 2 to 4 carbon atoms,

- t denotes a value ranging from 0 to 3 and preferably equal to 0,

- G denotes glucose, fructose or galactose, preferably glucose;

- the degree of polymerization, i.e. the value of v, possibly ranging from 1 to 15 and preferably from 1 to 4; the mean degree of polymerization more particularly being between 1 and 2.

The glucoside bonds between the sugar units are generally of 1-6 or 1-4 type and preferably of 1-4 type. C8/C16 alkyl (poly) glycosides 1, 4, and especially decyl glucosides, caprylyl/capryl glucosides, and coco-glucoside are most particularly preferred.

Among the commercial products, mention may be made of the products sold by the company COGNIS under the names

(600 CS/U, 1200 and 2000) or

(818, 1200 and 2000) ; the products sold by the company SEPPIC under the names ORAMIX CG 110 and ORAMIX NS 10; the products sold by the company BASF under the name LUTENSOL GD 70, or else the products sold by the company CHEM Y under the name AG10 LK.

Preferably, use is made of C8/C16-alkyl (poly) glycosides 1, 4, especially as an aqueous 53%solution, such as those sold by Cognis under the reference

818 UP.

Preferentially, the nonionic surfactants are chosen from C6-C24 alkyl polyglycosides, and more particularly C8-C18 alkyl (poly) glycosides, polyethoxylated C8-C30 fatty acid esters of sorbitan, polyethoxylated C8-C30 fatty alcohols and polyoxyethylenated C8-C30 fatty acid esters, these compounds preferably containing from 2 to 150 mol of ethylene oxide, and mixtures thereof.

Most preferably, the surfactant is selected from:

-C12-C20 acylglutamates, such as disodium stearoylglutamate, sodium stearoylglutamate;

- C12-C20 acyltaurates, especially sodium methyl stearoyl taurate;

- C14-18 carboxylates such as stearates, especially sodium stearate;

- C8-C18 alkyl (poly) glycosides, such as coco-glucoside;

- polyethoxylated fatty acid esters of sorbitan containing from 2 to 40 ethylene oxide units, such as polysorbate 60;

-polyethoxylated C8-C30 fatty alcohols containing from 2 to 40 ethylene oxide units, such as steareth-2; and

- a mixture thereof.

Advantageously, the surfactant is present in the composition according to the present invention in an amount ranging from 0.05 wt. %to 5 wt. %, preferably from 0.1 wt.%to 3 wt. %, relative to the total weight of the composition.

Solubilizing agents

According to the first aspect, when the fatty alcohol is solid at room temperature, the composition further comprises at least one solubilizing agent.

For the purpose of the present invention, the solubilizing agent is used to dissolve the fatty alcohol and decrease its crystallization temperature when mixed with the oil phase.

The solubility of the fatty alcohol in the solubilizing agent is not less than 5 g/100 g the solubilizing agent.

As used herein, the solubility is determined as follows:

Fatty alcohol is weighted into a solubilizing agent with gentle heating until fully dissolved, then the solution is cooled to room temperature and visually observe the development of solid crystals in the solution. The maximum concentration of the fatty alcohol that could be added to the solvent without the development of crystals at room temperature after three days is the solubility of fatty alcohol in this solubilizing agent.

Advantageously, the solubilizing agent is selected from low alcohols and polyols, preferably from ethanol, butanol, butylene glycol, propylene glycol, dipropylene glycol, and a mixture thereof.

If presents, advantageously, the solubilizing agent is present in the composition according to the present invention in an amount ranging from 0.5 wt. %to 40 wt. %, preferably from 0.5 wt. %to 20 wt. %, relative to the total weight of the composition.

Oil-soluble or oil-dispersible cosmetic active ingredients

The composition according to the present invention may comprise an oil-soluble or oil-dispersible cosmetic active ingredient.

Optionally, the oil-soluble or oil-dispersible cosmetic active ingredient is sensitive to heat and/or water.

As used herein, “cosmetic active ingredient is sensitive to heat and/or water” means that the cosmetic active ingredient will degrade in contact with heat and/or water.

For example, the oil-soluble or oil-dispersible cosmetic active ingredient can be selected from ferulic acid, Beta-Carotene, vitamin E (tocopherol) , enzymes, peptides, postbiotics, and encapsulated probiotics.

If presents, advantageously, the oil-soluble or oil-dispersible cosmetic active ingredient is present in the composition according to the present invention in an amount ranging from 0.05 wt. %to 10 wt. %, preferably from 0.05 wt. %to 5 wt. %, relative to 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 oil-soluble or oil-dispersible cosmetic active ingredient mentioned above.

As examples of cosmetic active ingredient, mention can be made of natural extracts; vitamins such as vitamin A (retinol) , 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-hydroxyacids 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 mixtures thereof.

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 comprise may also contain conventional cosmetic adjuvants or additives, for instance fragrances, chelating agents (for example, tetrasodium glutamate diacetate and disodium EDTA) , preserving agents (for example, chlorphenesin and phenoxyethanol) and bactericides, thickeners (such as xanthan gum, acrylamide/sodium acryloyldimethyltaurate copolymer, acrylates/C10-30 alkyl acrylate crosspolymer, hydroxypropyl guar; oil thickeners such as polyurethane, polyamide, ethylcellulose) , pH regulators (for example triethanolamine, citric acid and sodium hydroxide) , fillers (for examples aluminum starch octenylsuccinate and polymethiylsisesquioxane) 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 in the form of an oil-in-water emulsion for caring for and/or making up keratin materials comprising, relative to the total weight of the composition:

(i) from 1 wt. %to 10 wt. %of at least one fatty alcohol with a carbon-chain length of 12-16;

(ii) from 0.1 wt. %to 3 wt. %of at least one surfactant selected from C12-C20 acyl taurates;

(iii) from 0.5 wt. %to 20 wt. %of at least one solubilizing agent selected from ethanol, butanol, butylene glycol, propylene glycol, dipropylene glycol, and a mixture thereof; and

(iv) from 0.05 wt. %to 5wt. %of at least one oil-soluble or oil-dispersible cosmetic active ingredient.

Galenic form and method

The composition of the present invention is in the form of oil-in-water emulsion.

The composition according to the present invention has a lamellar structure or a lamellar structured-phase.

The term "lamellar structure" or "lamellar structured-phase" means a liquid crystal structure, or a swollen or non-swollen crystalline lamellar hydrate phase with plane symmetry, comprising several amphiphilic bilayers arranged in parallel and separated by a liquid medium which is generally water. Lamellar structure has a characteristic optical effect when observed with a light microscope under 90° cross polarized light with unique optical effects, as shown in Figure 1. If the unique optical effect can be observed, it means that the lamellar structure is formed.

The composition of the present invention can be used for caring for and/or making up keratin materials.

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

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

EXAMPLES

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

Table 1

Invention examples 1-7 and comparative examples 1-3

Compositions of invention examples (IE. ) 1-7 and comparative examples (CE. ) 1-3 were prepared according to the amounts given in Table 2. The amount of each component is given in%by weight of the active material relative to the total weight of the composition containing it.

Table 2

Compositions of invention examples (IE) 1-7 represent compositions according to the present invention.

Composition of comparative example 1 comprises a fatty alcohol being solid at room temperature but does not comprise any solubilizing agent.

Compositions of comparative examples 2-3 do not comprise any fatty alcohol with a carbon-chain length of 12-18.

Preparation process:

The compositions listed above were prepared as follows, taking the composition of invention example 5 as an example:

1) . Mixing myristal alcohol with caprylic/capric Triglyceride as the oily phase and then heating above 45℃ to fully melt myristal alcohol;

2) . Adding propylene glycol to the oily phase and cooling below 30℃;

3) . Adding Beta-Carotene pre-dissolved in Helianthus Annuus (Sunflower) Seed Oil to the oily phase;

4) . Preparing the water phase in a separate vessel to by mixing sodium methyl stearoyl taurate with water and heating till sodium methyl stearoyl taurate is fully dissolved, then adding glycerin to this vessel, and cooling below 30℃;

5) . Adding the oily phase to the water phase, homogenizing until an even emulsion was obtained.

Evaluation

Whether a lamellar structure is formed in each composition obtained was evaluated as follows.

Compositions was observed using a Leica DLMB microscope under 90° cross polarized light, and microscopic pictures were taken. If characteristic optical effects of lamellar structure were observed, it means that lamellar structure was formed.

Fig. 1 shows polarized light microscopy image of the composition obtained in invention example 1, wherein spherical structures are dispersed oil phases (indicated as 1’) , which are surrounded by the multi-lamellar interfaces (indicated as 2’) , and the alternating orange and blue color bands are the multi-lamellar water phase (indicated as 3’) .

Similar photos were also obtained for the compositions of invention examples 2-4 (IE. 2-4) .

Fig. 2 shows polarized light microscopy image of the composition obtained in invention example 5, whereinβ-carotene (indicated as 1) is dispersed within in the oil phase, surrounded by multi-lamellar interphases (indicated as 2) , and embedded in the lamellar continuous phase (indicated as 3) .

Similar photos were also obtained for the compositions of invention examples 5-7 (IE. 5-7)

It can be seen that a lamellar structure is formed in the compositions of invention examples 1-7 (IE. 1-7) .

Similar photos were not obtained for the compositions of comparative examples 1-3 (CE. 1-3) .

Formulation stability

The stability of a composition obtained was evaluated by incubating the composition at 45℃ for two months and then observing separation of phases and change in appearances. The stability test is passed if there is no change as compared with the initial status.

β-carotene degradation at 45℃ for 1 month

A stock solution ofβ-carotene was made by weighting 25mg of raw material containing 31 wt. %β-carotene in sunflower seed oil in 25ml volumetric flask and diluting with tetrahydrofuran (THF, inhibitor-free, HPLC grade, >99%, from Sigma-Aldrich) to a volume of 25 ml. The concentration ofβ-carotene in the stock solution was 310 mg/L. Astandard calibration curve ofβ-carotene was prepared using this stock solution, and five-point standard was generated with theoreticalβ-carotene concentrations of 1.55, 2.325, 3.100, 4.650, and 6.200 mg/L in THF. The absorbance ofβ-carotene was measured at its maximum absorbance wavelength of 450 nm using Thermo Scientific Evolution 220 UV-Visible Spectrophotometer. THF was used as blank. Proper amount of a sample containing β-carotene was then weighed according to the calibration range of the standard curve to determine itsβ-carotene concentration and degradation. Samples were dissolved in THF and then be filtered with PALL GxF/GHP 0.45μm filter to obtain the test solution. The same emulsion base without the raw material containing 31 wt. %β-carotene in sunflower seed oil was also prepared to identify matrix effect.

In order to minimize the impact of light onβ-carotene due to its photo sensitivity, sample preparations were performed in grey room (room with yellow light) .

Theβ-carotene degradation at 45℃ for 1 month was calculated according to the following equation:

(C _T0-C _T1M) /C _T0*100%

wherein

C _T0 indicates the content ofβ-carotene of the sample freshly made;

C _T1M indicates the content ofβ-carotene of the sample after being still at 45℃ for 1 month.

The accuracy of the quantification is±5%.

Ferulic acid degradation at 45℃ for 2 month

The ferulic acid content in each composition obtained was analyzed using high performance liquid chromatography (HPLC) equipped with a Waters X-Terra RP 1 column (3.9*150mm, 5μm) . The mobile phase was 0.1%trifluroacetic acid-methanol (60: 40) solution set at a flow rate of 1 mL/min with the column temperature at 30℃. The injection volume was 10μL. A UV detector was set at a wavelength at 323 nm to detect signals from ferulic acid and the retention time was about 4.2 minute. A ferulic acid standard cure was prepared by accurately weighting about 40 mg (two decimal places) of standard material into a 50 mL volumetric flask and dissolving with 60: 40 water-methanol to make a stock solution. 1 mL of the stock solution was diluted into 50 mL, 25 mL and 10 mL,which then measured with HPLC to generate the ferulic acid standard curve. Each composition was weighed into a 50 mL volumetric flask and diluted with 60: 40 water-methanol solution to pre-set volume and mix inside an ultrasonic bath before injecting into the HPLC unit.

The ferulic acid degradation at 45℃ for 2 months was calculated according to the following equation:

(C _T0-C _T2M) /C _T0*100%

wherein

C _T0 indicates the content of ferulic acid of the sample freshly made;

C _T2M indicates the content of ferulic acid of the sample after being still at 45℃ for 2 month.

The accuracy of the quantification methods is±5%.

Degradation under UV light

The degradation under UV light of a composition was evaluated by incubating the composition for 24 hours under UV light using a ATLAS 1605021 unit and determining the degradation of the cosmetic active ingredient contained therein according to the following equation:

(C _T0-C _T24H) /C _T0*100%

wherein

C _T0 indicates the content of the cosmetic active ingredient of the sample freshly made;

C _T24H indicates the content of the cosmetic active ingredient of the sample after being incubation under UV light for 24 hours.

The results of formulation stability, degradation under UV light, β-carotene degradation at 45℃ for 1 month, and Ferulic acid degradation at 45℃ for 2 months of each composition prepared above were listed in Table 3.

Table 3

NA: not tested.

It can be seen that compositions of invention examples 1-7 have a lamellar structure and have good stability, meanwhile can provide protection for oil cosmetic active ingredient therein.

Claims

A composition in the form of an oil-in-water emulsion for caring for and/or making up keratin materials, comprising:

(i) at least one fatty alcohol with a carbon-chain length of 12-18;

(ii) at least one surfactant, and

(iii) at least one solubilizing agent, wherein the solubility of the fatty alcohol in the solubilizing agent is not less than 5 g/100 g the solubilizing agent.
Composition according to claim 1, wherein the fatty alcohol is selected from lauryl alcohol, tridecyl alcohol, myristyl alcohol, pentadecyl alcohol, cetyl alcohol, oleyl alcohol, stearyl alcohol, cetearyl alcohol, and mixtures thereof.
Composition according to claim 1 or 2, wherein the fatty alcohol is present in an amount ranging from 0.5 wt. %to 25 wt. %, preferably from 1 wt. %to 10 wt. %, relative to the total weight of the composition.
Composition according to any of claims 1 to 3, wherein the surfactant is selected from

- C12-C20 acylglutamates;

- C12-C20 acyltaurates;

- C14-18 carboxylates;

- C8-C18 alkyl (poly) glycosides;

- polyethoxylated fatty acid esters of sorbitan containing from 2 to 40 ethylene oxide units;

- polyethoxylated C8-C30 fatty alcohols containing from 2 to 40 ethylene oxide units; and

- a mixture thereof.
Composition according to any of claims 1 to 4, wherein the surfactant is present in an amount ranging from 0.05 wt. %to 5 wt. %, preferably from 0.1 wt. %to 3 wt. %, relative to the total weight of the composition.
Composition according to any of claims 1 to 5, wherein the solubilizing agent is selected from polyols, preferably from ethanol, butanol, butylene glycol, propylene glycol, dipropylene glycol, and a mixture thereof.
The composition according to any of claims 1 to 6, wherein the solubilizing agent is present in an amount ranging from 0.5 wt. %to 40 wt. %, preferably from 0.5 wt. %to 20 wt. %, relative to the total weight of the composition.
The composition according to any of claims 1 to 7, further comprising an oil-soluble or oil-dispersible cosmetic active ingredient.
The composition according to claim 8, wherein the oil-soluble or oil-dispersible cosmetic active ingredient is present in an amount ranging from 0.05 wt. %to 10 wt. %, preferably from 0.05 wt. %to 5 wt. %, relative to the total weight of the composition.
Composition according to claim 1, comprising, relative to the total weight of the composition:

(i) from 1 wt. %to 10 wt. %of at least one fatty alcohol with a carbon-chain length of 12-16;

(ii) from 0.1 wt. %to 3 wt. %of at least one surfactant selected from C12-C20 acyltaurates;

(iii) from 0.5 wt. %to 20 wt. %of at least one solubilizing agent selected from ethanol, butanol, butylene glycol, propylene glycol, dipropylene glycol, and a mixture thereof; and

(iv) from 0.05 wt. %to 5 wt. %of at least one oil-soluble or oil-dispersible cosmetic active ingredient.
Composition according to any of claims 1-10, having a lamellar structure or a lamellar structured-phase.
A non-therapeutic method for caring for and/or making up keratin materials, comprising applying the composition according to any of claims 1 to 11 to the keratin materials.