FR3118872A1 - MULTIPHASE COMPOSITION COMPRISING AN ALPHA-HYDROXYACID - Google Patents

Abstract

Multiphase composition comprising an alpha-hydroxy acid The present invention relates to a multiphase cosmetic composition comprising at least one oily phase and at least one aqueous phase, comprising: (a) at least one polar oil, (b) at least one non-polar oil, (c) at least one alpha-hydroxy acid, and (d) water, in which the amount of the oily phase is within a range of 4 to 10% by weight based on the total weight of the composition; the weight ratio of (a) polar oil to (b) non-polar oil is greater than 1, the amount of (c) alpha-hydroxy acid is within a range of 1.5 to 5% by weight based on the total weight of the composition, and the oily phase and the aqueous phase form two separate layers on standing. Figure for abstract: NONE

Description

MULTIPHASE COMPOSITION COMPRISING AN ALPHA-HYDROXYACID

The present invention relates to a multiphasic composition comprising at least one alpha-hydroxy acid, preferably a cosmetic composition comprising the latter.

BACKGROUND OF THE INVENTION

Multiphase compositions comprising an aqueous phase and an oily phase have a benefit in their use thanks to their low viscosity. In addition, they have another benefit in their appearance since they do not exhibit a whitish appearance as emulsion compositions do.

For example, document WO 2014/098254 discloses an anhydrous cosmetic composition, comprising: (a) at least one oily phase including at least one oil; (b) at least one alcoholic phase including at least one alcohol; and (c) at least one nonionic surfactant phase including at least one nonionic surfactant, in which the nonionic surfactant is chosen from polyol esters with saturated or unsaturated chain fatty acids containing for example from 8 to 24 carbon, preferably 12 to 22 carbon atoms, and their alkoxylated derivatives with an alkylene oxide number of 10 to 200.

Furthermore, document EP 3157949 A1 presents an anhydrous composition comprising: at least one oily phase (A) comprising at least one oil, at least one anhydrous non-oily phase (B) comprising at least one polyol, at least one nonionic surfactant (i) having an HLB greater than 9, at least one nonionic surfactant (ii) having an HLB less than or equal to 9 in an amount at least equal to 0.2% by weight based on the weight of the anhydrous composition; wherein the nonionic surfactant (i) and the nonionic surfactant (ii) are present in the composition in a weight ratio of 5.5 to 12.5, and wherein said phases (A) and (B) are visually distinct one from the other.

A hydroxy acid, such as an alpha hydroxy acid (AHA) is commonly used as an exfoliant/peeling agent in cosmetics and dermatology. It is well known that an AHA activates protease in the stratum corneum to enhance the breakdown of corneodesmosomes, while in the dermal layer an AHA can promote collagen formation. This then leads to peeling of the skin, which improves the condition of the skin. Additionally, an AHA has been reported to also diminish facial pores and blackheads, most likely by targeting the activation of enzymes and protein functions related to sebum production.

On the other hand, although high-concentration alpha-hydroxy acids lead to a significant improvement in skin texture, alpha-hydroxy acids are also known to cause considerable discomfort on application and after application (redness , tingling and/or burning sensation). So far, there have been no reports of formulations that suppress skin discomfort while including high concentration alpha hydroxy acids.

DISCLOSURE OF INVENTION

One of the objects of the present invention is to provide a multiphase composition which can provide a good feeling on application to a keratinous substance such as the skin and a great improvement in the texture, while suppressing a feeling of discomfort after the app.

The aforementioned objective of the present invention can be achieved by a multiphase cosmetic composition comprising at least one oily phase and at least one aqueous phase, comprising:

(a) at least one polar oil,

(b) at least one non-polar oil,

(c) at least one alpha-hydroxy acid, and

(d) water,

in which

the amount of the oily phase is within a range of 4 to 10% by weight relative to the total weight of the composition;

the weight ratio of (a) polar oil to (b) non-polar oil is greater than 1,

the amount of (c) alpha-hydroxy acid is within a range of 1.5 to 5% by weight based on the total weight of the composition, and

the oily phase and the aqueous phase form two separate layers on standing.

The (a) polar oils may include at least one ether oil.

Ether oil can be represented by the following formula:

R ¹ -OR ²

in which

each of R ¹ and R ² independently represents a linear, branched or cyclic C ₄ -C ₂₄ alkyl group, preferably a C ₆ -C ₁₈ alkyl group, and more preferably a C ₈ -C ₁₂ alkyl group.

The (b) non-polar oil may include at least one hydrocarbon oil.

The (b) non-polar oil can comprise at least one natural oil.

The weight ratio of (a) polar oil to (b) non-polar oil may be 1 or more, preferably 1.5 or more, and even more preferably 2 or more, and in particular 2.3 or more. more, and/or may be 10 or less, preferably 7 or less, more preferably 5 or less, and even more preferably 4 or less, and especially 3 or less.

The (c) alpha-hydroxy acid may include at least one alkyl alpha hydroxy acid.

The amount of the (a) polar oil may be 2% by weight or more, preferably 3% by weight or more, more preferably 4% by weight or more, and even more preferably 4.5% by weight. or more, and/or may be 9.5% or less, preferably 9% by weight or less, more preferably 8% by weight or less, even more preferably 7% by weight or less, based on weight composition total.

The amount of the (b) nonpolar oil may be 0.5% by weight or more, preferably 1% by weight or more, more preferably 1.5% by weight or more, and even more preferably 1 8% by weight or more, and/or may be 5% or less, preferably 4% by weight or less, more preferably 3% by weight or less, even more preferably 2% by weight or less, based on the total weight of the composition.

The composition can be a biphasic composition.

The composition may further comprise at least one cosmetically active ingredient.

The composition may also comprise at least one cosmetically acceptable hydrophilic organic solvent.

The composition may comprise one or more particulates in an amount of less than 5% by weight or less, preferably 3% by weight or less, more preferably 1% by weight or less, even more preferably 0.5% by weight or less , and in particular 0.1% by weight or less, based on the total weight of the composition, or the composition is free of any particulate matter.

The composition may comprise one or more surfactants in an amount of less than 5% by weight or less, preferably less than 3% by weight or less, more preferably less than 1% by weight or less, even more preferably less than 0.5 % by weight or less, and in particular less than 0.1% by weight or less, relative to the total weight of the composition, or the composition is free of any surfactant.

The present invention also relates to a non-therapeutic cosmetic process for the care and/or conditioning of keratinous substances, such as the skin, comprising:

the application to keratinous substances of a multiphase cosmetic composition comprising at least one oily phase and at least one aqueous phase, comprising:

(a) at least one polar oil,

(b) at least one non-polar oil,

(c) at least one alpha-hydroxy acid, and

(d) water,

in which

the amount of the oily phase is within a range of 4 to 10% by weight relative to the total weight of the composition;

the weight ratio of (a) polar oil to (b) non-polar oil is greater than 1,

the amount of (c) alpha-hydroxy acid is within a range of 1.5 to 5% by weight based on the total weight of the composition, and

the oily phase and the aqueous phase form two separate layers on standing.

BEST MODE FOR IMPLEMENTING THE INVENTION

After diligent research, the inventors have surprisingly found that a combination of specific types of oils in a specific amount ratio can suppress skin discomfort due to high concentration alpha hydroxy acid and provide good feeling to application, thereby completing the present invention.

Thus, the composition according to the present invention is a multiphase cosmetic composition comprising at least one oily phase and at least one aqueous phase, comprising:

(a) at least one polar oil

(b) at least one non-polar oil,

(c) at least one alpha-hydroxy acid, and

(d) water,

in which

the amount of the oily phase is within a range of 4 to 10% by weight relative to the total weight of the composition;

the weight ratio of (a) polar oil to (b) non-polar oil is greater than 1,

the amount of (c) alpha-hydroxy acid is within a range of 1.5 to 5% by weight based on the total weight of the composition, and

the oily phase and the aqueous phase form two separate layers on standing.

Hereinafter, the composition, process and use according to the present invention will be explained in more detail.

[Composition]

The composition may be a cosmetic composition, preferably a cosmetic composition for a keratinous substance, and more preferably a cosmetic composition for caring for and/or conditioning a keratinous substance. The keratinous substance herein means a material containing keratin as a main constituent, and examples thereof are skin, scalp, lips and the like, and particularly skin.

The composition according to the present invention has a multiphase form. The term "multiphase" here denotes a composition comprising at least two layers separated at rest, in which each layer comprises or consists of an aqueous phase, an oily phase or an emulsion phase, such as a water-in-oil emulsion or an oil-in-water emulsion phase. The multiphase composition according to the present invention comprises at least one aqueous phase and one oily phase, and preferably consists of an aqueous phase and an oily phase. Consequently, the aqueous phase of the composition forms an aqueous layer on standing, and the oily phase of the composition forms an oily layer on standing, in which the aqueous layer and the oily layer are visually and/or macroscopically separated on standing in the composition.

In a preferred embodiment of the present invention, the composition may be a biphasic composition comprising only two phases of an aqueous phase and an oily phase, and the oily phase forms an oily layer and the aqueous phase forms an aqueous layer. , which are visually and/or macroscopically separated at rest. The biphasic composition according to the present invention comprises only two visually distinct layers at rest, the layers being respectively constituted by the continuous aqueous phase and the continuous oily phase.

The term “aqueous phase” designates here a liquid phase at room temperature (25°C), comprising water and optionally hydrophilic substances, soluble or dispersible in water.

The term “oily phase” designates here a liquid phase at ambient temperature, comprising at least one oil which is liquid at ambient temperature (25° C.) and at atmospheric pressure (10 ⁵ Pa) and optionally comprising lipophilic substances, soluble in the oil. or dispersible in oil. The term “liquid” means that a substance is liquid at 25°C under 1 atm.

The composition according to the present invention is intended to be used after having mixed each phase homogeneously, for example, by simply shaking it. The composition according to the present invention can preferably be used as a cosmetic skincare composition, in particular a leave-in peeling composition. The composition according to the present invention may be intended to be applied to a keratinous substance, preferably the skin.

The amount of the aqueous phase in the composition according to the present invention may be 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more, even more preferably 80% by weight or more, and in particular 85% by weight or more, and/or may be 99% by weight or less, preferably 97% by weight or less, more preferably 95% by weight or less, and even more preferably 93% by weight or less, based on the total weight of the composition.

The amount of the oily phase is within a range of 4 to 10% by weight based on the total weight of the composition. The amount of the oil phase may be preferably 5% by weight or more, and more preferably 6% by weight or more, and/or may be preferably 9.5% by weight or less, and more preferably 9% by weight or less, based on the total weight of the composition.

The composition according to the present invention comprises (a) at least one polar oil, (b) at least one non-polar oil, (c) at least one alpha-hydroxy acid, and (d) water. The ingredients of the composition will be described in detail below.

(Polar oil)

The composition according to the present invention comprises (a) at least one polar oil. Only one type of polar oil can be used, but two or more different types of polar oils can be used in combination.

The (a) polar oil forms the oily phase of the present invention. Therefore, the oily phase of the present invention comprises at least one (a) polar oil. Therefore, the (a) polar oil forms an oily layer upon standing in the composition.

The (a) polar oil can be selected from ether oil, ester oil, silicone oil, fatty alcohol and combinations thereof.

Ether oil can be volatile or nonvolatile, preferably nonvolatile.

It may be preferable to use, as the ether oil, dialkyl ethers such as those represented by the following formula:

R ¹ -OR ²

in which

each of R ¹ and R ² independently represents a linear, branched or cyclic C ₄ -C ₂₄ alkyl group, preferably a C ₆ -C ₁₈ alkyl group, and more preferably a C ₈ -C ₁₂ alkyl group. It may be preferable for R ¹ and R ² to be identical.

As the linear alkyl group, there may be mentioned a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, behenyl group, docosyl group, tricosyl group and tetracosyl group.

As the branched alkyl group, there may be mentioned a 1-methylpropyl group, a 2-methylpropyl group, a t-butyl group, a 1,1-dimethylpropyl group, a 3-methylhexyl group, a 5-methylhexyl group, a 1- ethylhexyl, 2-ethylhexyl group, 1-butylpentyl group, 5-methyloctyl group, 1-ethylhexyl group, 2-ethylhexyl group, 1-butylpentyl group, 5-methyloctyl group, 2-butyloctyl group, isotridecyl group, 2-pentylnonyl group, 2-hexyldecyl group, isostearyl group, 2-heptylundecyl group, 2-octyldodecyl group, 1,3-dimethylbutyl group, 1-(1-methylethyl)- 2-methylpropyl, a 1,1,3,3-tetramethylbutyl group, a 3,5,5-trimethylhexyl group, a 1-(2-methylpropyl)-3-methylbutyl group, a 3,7-dimethyloctyl group and a 2-(1,3,3-trimethylbutyl)-5,7,7-trimethyloctyl.

As the cyclic alkyl group, there can be mentioned a cyclohexyl group, a 3-methylcyclohexyl group and a 3,3,5-trimethylcyclohexyl group.

It may be preferred that the ether oil be selected from the group consisting of dicapryl ether, dicapryl ether, dilauryl ether, diisostearyl ether, dioctyl ether, nonylphenyl ether, dodecyl dimethylbutyl ether, cetyl dimethylbutyl ether, cetyl isobutyl ether, and their mixtures.

It may be more preferred that the ether oil be selected from the group consisting of dicapryl ether, dicapryl ether, dilauryl ether, diisostearyl ether, dioctyl ether, and mixtures thereof.

Ester oils are liquid esters of C ₁ -C ₂₆ aliphatic monoacids or polyacids, saturated or unsaturated, linear or branched, and of C ₁ -C ₂₆ aliphatic monoalcohols or polyalcohols, saturated or unsaturated, linear or branched, the total number of carbon atoms of the esters being greater than or equal to 10.

Preferably, for esters of monoalcohols, at least one of the alcohol and the acid from which the esters of the present invention are derived is branched.

Among the monoesters of monoacids and monoalcohols, mention may be made of ethyl palmitate, ethylhexyl palmitate, isopropyl palmitate, dicaprylyl carbonate, alkyl myristates such as isopropyl myristate or myristate ethyl ester, isocetyl stearate, 2-ethylhexyl isononanoate, isononyl isononanoate, isodecyl neopentanoate and isostearyl neopentanoate.

Esters of C ₄ -C ₂₂ dicarboxylic or tricarboxylic acids and of C ₁ -C ₂₂ alcohols, as well as esters of monocarboxylic, dicarboxylic or tricarboxylic acids and of dihydroxy, trihydroxy, tetrahydroxy or pentahydroxy C ₄ -C ₂₆ non sugar can also be used.

Mention may in particular be made of diethyl sebacate; isopropyl and lauroyl sarcosinate; diisopropyl sebacate; bis(2-ethylhexyl) sebacate; diisopropyl adipate; di-n-propyl adipate; dioctyl adipate; bis(2-ethylhexyl) adipate; diisostearyl adipate; bis(2-ethylhexyl) maleate; triisopropyl citrate; triisocetyl citrate; triisostearyl citrate; glyceryl trilactate; glyceryl trioctanoate; trioctyldodecyl citrate; trioleyl citrate; neopentyl glycol diheptanoate; diethylene glycol diisononanoate.

As ester oils, it is possible to use sugar esters and diesters of C ₆ -C ₃₀ and preferably C ₁₂ -C ₂₂ fatty acids. It is recalled that the term “sugar” denotes oxygenated hydrocarbon compounds containing several alcoholic functions, with or without aldehyde or ketone functions, and which contain at least 4 carbon atoms. These sugars can be monosaccharides, oligosaccharides or polysaccharides.

Examples of suitable sugars which may be mentioned include sucrose (or sucrose), glucose, galactose, ribose, fucose, maltose, fructose, mannose, arabinose, xylose and lactose, and their derivatives, in particular alkyl derivatives, such as methyl derivatives, for example methylglucose.

The esters of sugars of fatty acids can be chosen in particular from the group comprising the esters or mixtures of esters of sugars described above and of C ₆ -C ₃₀ and preferably C ₁₂ -C _{22 fatty} acids, linear or branched, saturated or unsaturated. If unsaturated, these compounds can have one to three conjugated or unconjugated carbon-carbon double bonds.

The esters according to this variant can also be chosen from monoesters, diesters, triesters, tetraesters and polyesters, and mixtures thereof.

These esters can be, for example, oleates, laurates, palmitates, myristates, behenates, cocoates, stearates, linoleates, linolenates, caprates and arachidonates, or mixtures thereof, in particular mixed esters of oleopalmitate, oleostearate and palmitostearate, as well as pentaerythrityl tetraethyl hexanoate.

More particularly, monoesters and diesters and in particular monooleates or dioleates, stearates, behenates, oleopalmitates, linoleates, linoleinates and oleostearates of sucrose, of glucose or of methylglucose are used.

An example which may be mentioned is the product sold under the name Glucate® DO by the company Amerchol, which is a methylglucose dioleate.

Examples of preferable ester oils include, for example, diisopropyl adipate, dioctyl adipate, 2-ethylhexyl hexanoate, ethyl laurate, cetyl octanoate, octyldodecyl octanoate, isodecyl neopentanoate, myristyl propionate, 2-ethylhexyl 2-ethylhexanoate, 2-ethylhexyl octanoate, 2-ethylhexyl caprylate/caprate, methyl palmitate, ethyl palmitate, isopropyl palmitate, dicaprylyl carbonate, isopropyl lauroyl sarcosinate, isononyl isononanoate, ethylhexyl palmitate, isohexyl laurate, hexyl laurate, isocetyl stearate, isopropyl isostearate, isopropyl myristate, isodecyl oleate, glyceryl tri(2-ethylhexanoate), tetra pentaerythrityl (2-ethylhexanoate), 2-ethylhexyl succinate, diethyl sebacate and mixtures thereof.

Examples of silicone oils include, for example, linear organopolysiloxanes such as dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane and the like; cyclic organopolysiloxanes such as cyclohexasiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane and the like; and their mixtures.

Preferably, the silicone oil is chosen from liquid polydialkylsiloxanes, in particular liquid polydimethylsiloxanes (PDMS) and liquid polyorganosiloxanes comprising at least one aryl group.

These silicone oils can also be organomodified. The organomodified silicones which can be used in accordance with the present invention are silicone oils as defined above and comprise in their structure one or more organofunctional groups linked by a group based on hydrocarbons.

Organopolysiloxanes are further defined in Walter Noll, Chemistry and Technology of Silicones (1968), Academic Press. They can be volatile or non-volatile.

When they are volatile, silicones are more particularly chosen from those having a boiling point of between 60°C and 260°C.

Non-volatile polydialkylsiloxanes can also be used. These non-volatile silicones are more particularly chosen from polydialkylsiloxanes, among which there may be mentioned mainly polydimethylsiloxanes containing terminal trimethylsilyl groups.

Among these polydialkylsiloxanes, mention may be made, without limitation, of the following commercial products:

- Silbione® oils of the 47 and 70 047 series or Mirasil® oils sold by Rhodia, for example oil 70 047 V 500 000;

- the oils of the Mirasil® series sold by the company Rhodia;

- 200 series oils from Dow Corning, for example DC200 with a viscosity of 60,000 mm ² /s

- Viscasil® oils from General Electric and certain oils of the SF series (SF 96, SF 18) from General Electric.

Mention may also be made of polydimethylsiloxanes containing dimethylsilanol terminal groups known under the name of dimethiconol (CTFA), such as the oils of the 48 series from the company Rhodia.

Among the silicones containing aryl groups, mention may be made of polydiarylsiloxanes, in particular polydiphenylsiloxanes and polyalkylarylsiloxanes such as phenyl-silicone oil.

Examples that may be mentioned include products sold under the following names:

- Silbione® oils of the 70 641 series from Rhodia;

- oils of the Rhodorsil® 70 633 and 763 series from Rhodia;

- Dow Corning 556 Cosmetic Grade Fluid oil from Dow Corning;

- Bayer's PK series silicones, such as the PK20 product;

- certain General Electric SF series oils, such as SF 1023, SF 1154, SF 1250 and SF 1265.

Like phenyl silicone oil, phenyltrimethicone is preferred.

The organomodified liquid silicones may in particular contain polyethyleneoxy and/or polypropyleneoxy groups. Mention may thus be made of the KF-6017 silicone offered by Shin-Etsu, and the Silwet® L722 and L77 oils from Union Carbide.

The term "fatty" in fatty alcohol means the inclusion of a relatively large number of carbon atoms. Thus, alcohols that have 4 or more carbon atoms, preferably 6 or more, and more preferably 12 or more, fall within the scope of fatty alcohols. Fatty alcohol can be saturated or unsaturated. Fatty alcohol can be linear or branched.

The fatty alcohol can have the R-OH structure in which R is chosen from saturated and unsaturated, linear and branched radicals, containing from 4 to 40 carbon atoms, preferably from 6 to 30 carbon atoms, and more preferably from 12 to 20 carbon atoms. In at least one embodiment, R may be selected from C ₁₂ -C ₂₀ alkyl and C ₁₂ -C ₂₀ alkenyl groups. R may or may not be substituted with at least one hydroxyl group.

Examples of fatty alcohol include lauryl alcohol, cetyl alcohol, stearyl alcohol, isostearyl alcohol, behenyl alcohol, undecylenic alcohol, myristyl alcohol, octyldodecanol, hexyldecanol, oleyl alcohol, linoleyl alcohol, palmitoleyl alcohol, arachidonic alcohol, erucic alcohol and mixtures thereof.

It is preferred that the fatty alcohol be a saturated fatty alcohol.

Thus, the fatty alcohol can be chosen from saturated or unsaturated, linear or branched C ₆ -C ₃₀ alcohols, preferably linear or branched saturated C ₆ -C ₃₀ alcohols, and more preferably saturated C ₁₂ alcohols. -C ₂₀ linear or branched.

The term "saturated fatty alcohol" here denotes an alcohol having a long saturated aliphatic carbon chain. It is preferable for the saturated fatty alcohol to be chosen from all saturated C ₆ -C ₃₀ fatty alcohols, linear or branched. Among the linear or branched saturated C ₆ -C ₃₀ fatty alcohols, linear or branched saturated C ₁₂ -C ₂₀ fatty alcohols can preferably be used. Among the saturated C ₁₆ -C ₂₀ fatty alcohols, linear or branched, it is possible to preferably use saturated C ₁₆ -C ₂₀ fatty alcohols, linear or branched. The branched C ₁₆ -C ₂₀ fatty alcohols can be used even more preferentially.

Examples of saturated fatty alcohols include lauryl alcohol, cetyl alcohol, stearyl alcohol, isostearyl alcohol, behenyl alcohol, undecylenic alcohol, myristyl alcohol, octyldodecanol, hexyldecanol and mixtures thereof. In one embodiment, cetyl alcohol, stearyl alcohol, octyldodecanol, hexyldecanol, or a mixture thereof (e.g., cetearyl alcohol) as well as behenyl alcohol, can be used. as a saturated fatty alcohol.

In a preferred embodiment of the present invention, the (a) polar oil is chosen from ether oils as mentioned above.

The polar oil(s) may be present in an amount of 1% by weight or more, preferably 2% by weight or more, more preferably 3% by weight or more, and in particular 4% by weight or more, and/or may be present in an amount of 9% by weight or less, preferably 8% by weight or less, preferably 7.5% by weight or less, and in particular 7% by weight or less, based on the total weight of the composition.

(Non-polar oil)

The composition according to the present invention comprises (b) at least one non-polar oil. Only one type of nonpolar oil can be used, but two or more different types of nonpolar oils can be used in combination.

The (b) non-polar oil forms the oil phase of the present invention. Therefore, the oil phase of the present invention comprises at least one (b) non-polar oil. Therefore, the (b) non-polar oil forms an oily layer upon standing in the composition.

The (b) non-polar oil can be chosen from hydrocarbon oils.

The hydrocarbon oils can be chosen from:

- C ₆ -C ₁₆ lower alkanes, linear or branched, optionally cyclic. Examples which may be mentioned include hexane, undecane, dodecane, tridecane and isoparaffins, e.g. isohexadecane, isododecane and isodecane

- linear or branched hydrocarbons containing more than 16 carbon atoms, such as liquid paraffins, liquid petroleum jelly, polydecenes and hydrogenated polyisobutenes such as Parleam, and squalane.

Examples of hydrocarbon oils include, for example, linear or branched hydrocarbons such as isohexadecane, isododecane, squalane, mineral oil (e.g. liquid paraffin), paraffin, petroleum jelly or petrolatum, naphthalenes and the like; hydrogenated polyisobutene, isoeicosan, and decene/butene copolymer; and their mixtures.

In a preferred embodiment of the present invention, the (b) non-polar oil can be chosen from those of natural oils, for example oils of plant origin, such as squalene and triglycerides.

In yet another preferred embodiment of the present invention, the oily phase of the composition comprises a combination of (a) polar oil selected from ether oils and (b) non-polar oil selected from ether oils. hydrocarbon, as explained above.

In yet another preferred embodiment of the present invention, the oily phase of the composition comprises a combination of (a) a polar oil chosen from ether oils and (b) a non-polar oil chosen from natural oils , as explained above.

The non-polar oil(s) may be present in an amount of 0.5% by weight or more, more preferably 1% by weight or more, even more preferably 1.5% by weight or more, and in particular 1.8% by weight or more, and/or may be present in an amount of 8% by weight or less, preferably 6% by weight or less, more preferably 5% by weight or less, and in particular 3% by weight or less, relative to the total weight of the composition.

In the present invention, the weight ratio of (a) polar oil to (b) non-polar oil in the composition is greater than 0.5. In preferred embodiments of the present invention, the weight ratio of (a) polar oil to (b) non-polar oil in the composition may be 1 or more, more preferably 1.5 or more, and even more preferably 2 or more, and in particular 2.3 or more, and/or may be 10 or less, preferably 7 or less, more preferably 5 or less, and even more preferably 4 or less, and in particular of 3 or less.

(Alpha-Hydroxy Acid)

The composition according to the present invention may comprise at least one (c) alpha-hydroxy acid. Only one type of alpha hydroxy acid can be used, but two or more different types of alpha hydroxy acids can be used in combination.

The (c) alpha-hydroxy acid forms the aqueous phase of the present invention. Therefore, the aqueous phase of the present invention comprises at least one (c) alpha-hydroxy acid. Therefore, the (c) alpha-hydroxy acid forms an aqueous layer upon standing in the composition.

The term "alpha-hydroxy acid", "α-hydroxy acid", or "AHA" herein means a carboxylic acid that has at least one hydroxyl group on the adjacent (alpha) carbon atom.

The α-hydroxy acid can be represented by the following chemical formula:

(R _a )(R _b )C(OH)COOH

Or

R _a and R _b are H, F, Cl, Br, I, an alkyl, aralkyl or aryl group, saturated or unsaturated, isomeric or not, straight or branched chain or cyclic, having 1 to 25 carbon atoms, and besides R _a and R _b can bear an OH, CHO, COOH and alkoxyl group having 1 to 9 carbon atoms.

The hydrogen atom attached to the carbon atom can be substituted by F, Cl, Br, I, or a lower alkyl, aralkyl, aryl or alkoxyl group having 1 to 9 carbon atoms. The alpha-hydroxy acid can be present as a free acid or a lactone, or as a partial salt with an organic base or an inorganic alkali. Alpha hydroxy acids can exist as stereoisomers such as D, L, DL and meso forms.

When R _a and R _b are alkyl groups, they may be independently in any of the groups C ₁ -C ₅ , C ₆ -C ₁₀ , C ₁₁ -C ₁₅ , C ₁₆ -C ₂₀ , C ₂₁ - _C25 and _C26 - _C29 . The compounds of the chemical formula above therefore include all possible combinations of R _a and R _b . Included in the above is a sub-genus of compounds having R _a and R _b chosen independently from the C ₁ -C ₁₂ groups.

Typical alkyl, aralkyl, aryl and alkoxyl groups for R _a and R _b include methyl, ethyl, propyl, isopropyl, butyl, pentyl, octyl, lauryl, stearyl, benzyl, phenyl, methoxyl and ethoxyl groups.

The alpha-hydroxy acids of the first group can be subdivided into

(1) alkyl alpha hydroxy acids,

(2) aralkyl and aryl alpha-hydroxy acids,

(3) poly(hydroxy alpha hydroxy acids),

(4) poly(alpha-hydroxy carboxylic acids), and

(5) various alpha-hydroxy acids.

The following alpha-hydroxy acids are representative of each subgroup.

(1) Alkyl alpha hydroxy acids: 2-hydroxyethanoic acid (glycolic acid), 2-hydroxypropanoic acid (lactic acid), 2-methyl-2-hydroxypropanoic acid (methyllactic acid), 2-hydroxybutanoic acid, 2-hydroxypentanoic acid , 2-hydroxyhexanoic acid, 2-hydroxyheptanoic acid, 2-hydroxyoctanoic acid, 2-hydroxynonanoic acid, 2-hydroxydecanoic acid, 2-hydroxyundecanoic acid, 2-hydroxydodecanoic acid, 2-hydroxytetradecanoic acid, 2-hydroxyhexadecanoic acid, 2-hydroxyoctadecanoic acid , 2-hydroxyeicosanoic acid (alpha hydroxyarachidonic acid), 2-hydroxytetraeicosanoic acid (cerebronic acid), 2-hydroxytetraeicosanoic acid (alpha hydroxynervonic acid) and 2,4-dihydroxy-3,3-dimethylbutanoic acid (pantoic acid)

(2) aralkyl and aryl alpha-hydroxy acids: 2-phenyl-2-hydroxyethanoic acid (mandelic acid); 2,2-diphenyl-2-hydroxyethanoic acid (benzilic acid), 3-phenyl-2-hydroxypropanoic acid (phenyllactic acid), 2-phenyl-2-methyl-2-hydroxyethanoic acid (atrolactic acid) and 4-hydroxymandelic acid.

(3) poly(hydroxy alpha hydroxy acids): 2,3-dihydroxypropanoic acid (glyceric acid); 2,3,4-trihydroxybutanoic acid (isomers; erythronic acid, threonic acid); 2,3,4,5-tetrahydroxypentanoic acid (isomers; ribonic acid, arabinoic acid, xylonic acid, lyxonic acid); 2,3,4,5,6-pentahydroxyhexanoic acid (isomers; allonic acid, altronic acid, gluconic acid, mannoic acid, gulonic acid, idonic acid, galactonic acid, talonic acid); 2,3,4,5,6,7-hexahydroxyheptanoic acid (isomers; glucoheptonic acid, galactoheptonic acid, mannoheptonic acid, etc.)

(4) poly(alpha-hydroxy carboxylic acids): 2-hydroxypropane-1,3-dioic acid (tartronic acid); 2-hydroxybutane-1,4-dioic acid (malic acid); 2-hydroxy-2-methylbutane-1,4-dioic acid (citramalic acid); 2,3-dihydroxybutane-1,4-dioic acid (tartaric acid); 2,3,4-trihydroxypentane-1,5-dioic acid (isomers: ribaric acid, arabic acid, xylaric acid, lyxaric acid); 2,3,4,5-tetrahydroxyhexane-1,6-dioic acid (isomers; glucaric acid, galactaric acid, mannaric acid, allaric acid, altraric acid, gularic acid, idaric acid, talaric acid); 2-hydroxy-1,2,3-propanetricarboxylic acid (citric acid); 1-hydroxy-1,2,3-propanetricarboxylic acid (isocitric acid); 1-hydroxy-1,2,4-butanetricarboxylic acid (homosocitric acid); 2-hydroxy-3-hexadecyl-1,2,3-propanetricarboxylic acid (n-hexadecyl citric acid; agaric acid).

(5) various alpha-hydroxy acids: glyceronic acid, erythruronic acid, threuronic acid; 2,3,4-trihydroxypentanuronic acids (isomers; riburonic acid, arabinuronic acid, xyluronic acid, lyxuronic acid); 2,3,4,5-tetrahydroxyhexanuronic acid (isomers; alluronic acid, altruronic acid, glucuronic acid, mannuronic acid, guluronic acid, iduronic acid, galacturonic acid, taluronic acid); 2,3,4,5,6-pentahydroxyheptanuronic acid (isomers; alloheptanuronic acid, altroheptanuronic acid, glucoheptanuronic acid, mannoheptanuronic acid, guloheptanuronic acid, idoheptanuronic acid, galactoheptanuronic acid, taloheptanuronic acid).

The alpha-hydroxy acid can be selected, for example, from the group consisting of glycolic acid, lactic acid, malic acid, citric acid, tartaric acid, mandelic acid, gluconic acid and mixtures thereof, preferably from the group consisting of glycolic acid, lactic acid and mixtures thereof, more preferably glycolic acid.

The (c) alpha-hydroxy acid(s) is (are) present in the composition in an amount of 1.5 to 5% by weight relative to the total weight of the composition. In the preferred embodiments of the present invention, the alpha-hydroxy acid(s) may be present in an amount of 2% by weight or more, more preferably 3% by weight. weight or more, even more preferably 3.5% by weight or more, and especially 4% by weight or more, and/or may be present in an amount of 4.8% by weight or less, preferably 4 6% by weight or less, and in particular 4.4% by weight or less, relative to the total weight of the composition.

(Water)

The composition according to the present invention comprises (d) water. Water forms the aqueous phase of the present invention. Therefore, the aqueous phase of the composition includes water. The (d) water forms an aqueous layer upon standing in the composition.

(d) water may be present in an amount of 50% by weight or more, preferably 55% by weight or more, more preferably 60% by weight or more, even more preferably 65% by weight or more, preferably 70% by weight or more, and in particular 75% by weight or more, and/or may be present in an amount of 95% by weight or less, preferably 90% by weight or less, more preferably of 85% by weight or less, and in particular of 80% by weight or less, relative to the total weight of the composition.

(Hydrophilic organic solvent)

The composition according to the present invention may comprise at least one cosmetically acceptable hydrophilic organic solvent.

The term “hydrophilic” designates here substances having a solubility of at least 1 g/L, preferably of at least 10 g/L, and more preferably of at least 100 g/L, in water at temperature ambient (25°C) and at atmospheric pressure (10 ⁵ Pa). Therefore, the cosmetically acceptable hydrophilic organic solvent is included in the aqueous phase, if present.

The cosmetically acceptable hydrophilic organic solvent(s) may include, for example, substantially linear or branched lower mono-alcohols having 1 to 8 carbon atoms, such as ethanol, propanol, butanol, isopropanol and isobutanol; aromatic alcohols, such as benzyl alcohol and phenylethyl alcohol; polyols or polyol ethers, such as propylene glycol, dipropylene glycol, isoprene glycol, butylene glycol, glycerine, propanediol, pentylene glycol, caprylyl glycol, sorbitol, monomethyl, monoethyl ethers and ethylene glycol monobutyl ethers, propylene glycol ethers, propylene glycol monomethyl ether, diethylene glycol alkyl ethers, such as diethylene glycol monoethyl ether or monobutyl ether; polyethylene glycols, such as PEG-4, PEG-6 and PEG-8, and their derivatives, and a combination thereof.

The amount of cosmetically acceptable hydrophilic organic solvent(s) in the composition according to the present invention may be 1% by weight or more, preferably 3% by weight or more, more preferably 5% by weight or more, even more preferably 7% by weight or more, and in particular 10% by weight or more, and/or may be 30% by weight or less, preferably 20% by weight or less, and more preferably 15% by weight or less, relative to the total weight of the composition.

(pH adjusting agent)

The pH of the composition according to the present invention can be adjusted to the desired value by using at least one pH adjusting agent, such as an acidifying or basifying agent, for example, which are commonly used in cosmetic products.

The pH of the composition according to the present invention may be 8.0 or less, preferably 7.0 or less, more preferably 6.0 or less, even more preferably 5.0 or less, and in particular 4.5 or less, and/or may be 2.5 or more, preferably 3.0 or more, more preferably 3.5 or more, and particularly 4.0 or more at 25℃.

Among the acidifying agents, mention may be made, by way of example, of mineral or organic acids such as hydrochloric acid, orthophosphoric acid, sulfuric acid, carboxylic acids such as acetic acid, tartaric acid, citric acid and lactic acid, and sulfonic acids.

Among the basifying agents, mention may be made, by way of example, of the hydroxides of an alkali or alkaline-earth metal, for example sodium or potassium hydroxide; quaternary ammonium hydroxides and guanidinium hydroxide; alkali metal silicates, such as sodium metasilicates; amino acids, preferably basic, such as arginine, lysine, ornithine, citrulline and histidine; carbonates and bicarbonates, in particular of a primary, secondary or tertiary amine, of an alkali or alkaline-earth metal, or of ammonium; and the compounds of the following formula:

in which

W is a C ₁ -C ₆ alkylene residue optionally substituted by a hydroxyl group or a C ₁ -C ₆ alkyl group;

Rx, Ry, Rz and Rt, which may be the same or different, represent a hydrogen atom or a C ₁ -C ₆ alkyl, C ₁ -C ₆ hydroxyalkyl or C ₁ -C ₆ aminoalkyl group. Mention may in particular be made of 1,3-diaminopropane, 1,3-diamino-2-propanol, spermine and spermidine.

The pH adjusting agent(s) may be used in an amount ranging from 0.001% to 15% by weight, preferably from 0.01% to 12% by weight. weight, and more preferably from 0.1% to 10% by weight, based on the total weight of the composition.

(Active ingredient)

The composition according to the present invention may comprise at least one optional active cosmetic ingredient. The term "active ingredient" used herein means an organic compound having cosmetic or dermatological effects on a keratinous substance, such as the skin. Cosmetic active ingredients well known in the cosmetic field can be used as optional active ingredients. Preferably, the additional cosmetic ingredient is an active ingredient intended to heal or condition keratinous substances, such as the skin. For example, the active ingredients are intended to improve the condition of keratinous substances, such as the skin.

Preferably, the active cosmetic ingredient is included in the aqueous phase, if present.

Examples of skin whitening ingredients include L-ascorbic acids and their derivatives, salicylic acid and its derivatives, such as alkoxysalicylic acids, hydroquinone glycosides and their derivatives, tranexamic acids and their derivatives, resorcinol derivatives, koji acids and their derivatives, cinnamaldehyde or its derivatives and ellagic acid. Examples of anti-aging ingredients include vitamins such as retinol, saponin and allantoin. Among the antioxidant ingredients, mention may be made, for example, of carotenoids such as β-cryptoxanthin, tocopherol and its derivatives, and flavonoids.

The amount of the optional active ingredient(s) in the composition according to the present invention may be 0.01% by weight or more, preferably 0.05% by weight or more, more preferably 0.1 wt% or more, and still more preferably 0.15 wt% or more, and may be 10 wt% or less, preferably 5 wt% or less, more preferably 3 wt% or less, and even more preferably 1 wt% or less, based on the total weight of the composition.

(Additives)

The composition according to the present invention may also comprise any (all) adjuvant(s) usually used in the field of cosmetics, chosen, for example, from anionic, cationic, nonionic or amphoteric polymers, anionic, cationic surfactants , nonionic or amphoteric, hydrophobic organic solvents, gums, resins, thickeners, antioxidants, buffers, organic or inorganic fillers, preservatives, such as phenoxyethanol, co-preservatives, opacifiers , perfumes, neutralizers, antiseptics, UV filters, stabilizers or electrolytes, such as sodium chloride, chelating agents, dispersing agents, dyes and/or pigments, emollients or skin protection agents. collagen, and mixtures thereof.

The adjuvants can be present in the composition of the present invention in an amount preferably ranging from 0.01% to 30% by weight, preferably from 0.1% to 20% by weight, and more preferably from 0.5% to 10% by weight, based on the total weight of the composition.

In another preferred embodiment of the present invention, the composition preferably includes one or more particulate materials, such as fillers, in an amount of less than 5 wt% or less, preferably 3 wt% or less, more preferably 1% by weight or less, even more preferably 0.5% by weight or less, and especially 0.1% by weight or less, based on the total weight of the composition. In another preferred embodiment of the present invention, the composition is free of any particulate matter.

In another preferred embodiment of the present invention, the composition preferably includes one or more surfactants in an amount of less than 5 wt% or less, preferably 3 wt% or less, more preferably 1 wt% or less , even more preferably 0.5% by weight or less, and in particular 0.1% by weight or less, based on the total weight of the composition. In another preferred embodiment of the present invention, the composition is free of any surfactant.

The composition according to the present invention can be prepared by mixing the essential and optional ingredients described above in a conventional manner. It is also possible to mix any of the optional ingredients together and heat the composition until one ingredient is dissolved.

[Cosmetic process and process]

The present invention also relates to a non-therapeutic process or method, preferably a cosmetic process or method, and more preferably a cosmetic process or method for caring for and/or conditioning keratinous substances, such as the skin, the scalp and the lips, in particular the skin, comprising: the application to the keratinous substance of a multiphase cosmetic composition comprising at least one oily phase and at least one aqueous phase, comprising:

(a) at least one polar oil,

(b) at least one non-polar oil,

(c) at least one alpha-hydroxy acid, and

(d) water,

in which

the amount of the oily phase is within a range of 4 to 10% by weight relative to the total weight of the composition; the weight ratio of (a) polar oil to (b) non-polar oil is greater than 1,

the amount of (c) alpha-hydroxy acid is in the range of 1.5 to 5% by weight based on the total weight of the composition, and the oil phase and the water phase form two separate layers upon standing

The present invention also relates to a non-therapeutic process or method, preferably a cosmetic process or method, and more preferably a cosmetic process or method for caring for and/or conditioning keratinous substances, such as the skin, the scalp , and the lips, in particular the skin, comprising: the application to the keratinous substance of a multiphase cosmetic composition comprising at least one oily phase and at least one aqueous phase, comprising:

(a) at least one ether oil,

(b) at least one hydrocarbon oil or one natural oil, which is a non-polar oil,

(c) at least one alpha-hydroxy acid, and

(d) water,

in which

the amount of the oily phase is within a range of 4 to 10% by weight relative to the total weight of the composition; the weight ratio of (a) polar oil to (b) non-polar oil is greater than 1,

the amount of (c) alpha-hydroxy acid is in a range of 1.5 to 5% by weight based on the total weight of the composition, and the oily phase and the aqueous phase form two separate layers on standing.

The process or process according to the present invention may also comprise another step consisting in mixing the aqueous phase and the oily phase of the present invention before the application to the keratinous substance, so as to obtain a homogeneous composition.

The same explanations for the composition, (a) polar oil, (b) non-polar oil, (c) alpha-hydroxy acid and (d) water in the composition according to the present invention above can be applied to the composition, (a) polar oil, (b) non-polar oil, (c) alpha-hydroxy acid and (d) water for the method, process and use according to the present invention. The composition used in the process, method and use according to the present invention may include any of the optional ingredients as explained above for the composition according to the present invention.

EXAMPLES

The present invention will be described in more detail using examples which should not, however, be interpreted as limiting the scope of the present invention.

[Compositions]

The homogeneous solution compositions according to the Examples and Comparative Examples were prepared by mixing the ingredients listed in Tables 1 to 4 with a magnetic stirrer at room temperature (25°C). The numerical values of the amounts of ingredients shown in Table 1 are all based on the "% by weight" of active raw materials.

[Assessment]

(Skin discomfort)

Each of the compositions was shaken 10 times in a container in order to be homogeneous, then applied to the facial skin of the members of the panel (n=6) with a cotton ball and in a controlled quantity. The sensation of skin discomfort, such as redness, tingling and/or burning sensation, for each composition were evaluated after application according to the following criteria.

Very good: no skin discomfort

Good: slight skin discomfort but acceptable

Bad: skin discomfort

Very bad: obvious skin discomfort

(Skin feel on application)

Each of the compositions was shaken 10 times in a container in order to be homogeneous, then applied to the facial skin of the members of the panel (n=6) with a cotton ball and in a controlled quantity. The skin sensation on application was evaluated for each composition according to the following criteria.

Very good: moist but not greasy

Good: moist but slightly greasy

Bad: no feeling of humidity but greasy

Very bad: no feeling of humidity at all but a very important feeling of fat

(Improved skin texture)

The improvement in skin texture after application was assessed by a protocol of trained experts. Each of the compositions was shaken 10 times in a container in order to be homogeneous, then applied to the facial skin of the members of the panel (n=6) with a cotton ball and in a controlled quantity. The improvement in skin texture for each composition was evaluated after two weeks from application according to the following criteria.

Good: significant improvement

Bad: no improvement

(Structure of the formula)

The appearance of each of the compositions was observed with the naked eye to determine whether it has a multiphasic (biphasic) structure or not.

The results are shown in Table 1 below.

As shown in Table 1, the compositions according to the examples, which include the specific combination of (a) polar oil, (b) non-polar oil, (c) alpha-hydroxy acid and (d) water in the amounts Specific compounds according to the present invention exhibited excellent skin feel upon application and great improvement in skin texture after application, while suppressing skin discomfort due to high concentration alpha-hydroxy acid.

In contrast, the composition according to Comparative Example 1, which does not include the alpha-hydroxy acid, showed no improvement in skin texture. The composition according to Comparative Example 2, which does not include oils, did not show a tolerable relief of skin discomfort and gave an unpleasant feeling on application. The composition according to Comparative Example 3, which includes a polar oil and a non-polar oil in a weight ratio outside the scope of the present invention, and the composition according to Comparative Example 4, which does not include non-polar, did not feel good on application. The composition according to Comparative Example 5, which does not include a polar oil and a non-polar oil and the total oil concentration is less than 4%, and the composition according to Comparative Example 7, which includes an alpha-hydroxy acid in too high a concentration, did not eliminate skin discomfort after application. The composition according to Comparative Example 6, which includes an oily phase at too high a concentration, did not present a feeling of cutaneous comfort on application due to a greasy feeling.

Consequently, it can be concluded that the compositions according to the present invention are very suitable as cosmetic compositions for the care and/or conditioning of keratinous substances, such as the skin, since they can provide cosmetic effects and a satisfactory feeling to the application, while eliminating skin discomfort.

Claims (10)

Multiphase cosmetic composition comprising at least one oily phase and at least one aqueous phase, comprising:
(a) at least one polar oil,
(b) at least one non-polar oil,
(c) at least one alpha-hydroxy acid, and
(d) water,
in which
the amount of the oily phase is within a range of 4 to 10% by weight relative to the total weight of the composition;
the weight ratio of (a) polar oil to (b) non-polar oil is greater than 1,
the amount of (c) alpha-hydroxy acid is within a range of 1.5 to 5% by weight based on the total weight of the composition, and
the oily phase and the aqueous phase form two separate layers on standing. A composition according to claim 1, wherein the (a) polar oil comprises at least one ether oil. A composition according to any preceding claim, wherein the (b) non-polar oil comprises at least one natural oil. A composition according to any preceding claim, wherein the weight ratio of (a) polar oil to (b) non-polar oil is 1 or more, preferably 1.5 or more, and even more preferably 2 or more, and especially 2.3 or more, and/or is 10 or less, preferably 7 or less, more preferably 5 or less, even more preferably 4 or less, and especially 3 or less. A composition according to any preceding claim, wherein the amount of (a) polar oil is 2% by weight or more, preferably 3% by weight or more, more preferably 4% by weight or more, and even more preferably 4.5 wt% or more, and/or is 9.5 wt% or less, preferably 9 wt% or less, more preferably 8 wt% or less, even more preferably 7% by weight or less, based on the total weight of the composition. A composition according to any preceding claim, wherein the amount of (b) non-polar oil is 0.5% by weight or more, preferably 1% by weight or more, more preferably 1.5% by weight or more, and even more preferably 1.8% by weight or more, and/or is 5% or less, preferably 4% by weight or less, more preferably 3% by weight or less, further more preferably 2% by weight or less, based on the total weight of the composition. Composition according to one of the preceding claims, in which the composition is a biphasic composition. A composition according to any preceding claim, wherein the composition comprises one or more particulate materials in an amount of less than 5 wt% or less, preferably 3 wt% or less, more preferably 1 wt% or less, even more preferably 0.5% by weight or less, and especially 0.1% by weight or less, based on the total weight of the composition, or the composition is free of any particulate material. A composition according to any preceding claim, wherein the composition comprises one or more surfactants in an amount of less than 5 wt% or less, preferably 3 wt% or less, more preferably 1 wt% or less, and even more preferably 0.5% by weight or less, and in particular 0.1% by weight or less, based on the total weight of the composition, or the composition is free of any surfactant. Non-therapeutic cosmetic process for the care and/or conditioning of keratinous substances, such as the skin, comprising:
the application to the keratinous substances of a multiphase cosmetic composition comprising at least one oily phase and at least one aqueous phase, comprising:
(a) at least one polar oil,
(b) at least one non-polar oil,
(c) at least one alpha-hydroxy acid, and
(d) water,
in which
the amount of the oily phase is within a range of 4 to 10% by weight relative to the total weight of the composition;
the weight ratio of (a) polar oil to (b) non-polar oil is greater than 1,
the amount of (c) alpha-hydroxy acid is within a range of 1.5 to 5% by weight based on the total weight of the composition, and
the oily phase and the aqueous phase form two separate layers on standing.