Cosmetic composition in the form of a micro- or nano-emulsion rich in oil and its use for cleansing the human body

Abstract

The present invention relates to a cosmetic composition in the form of an oil-rich micro- or nano-emulsion, and its cosmetic use for cleansing the human body, particularly as a shower oil or makeup remover. It also relates to a cosmetic method for cleansing the human body, comprising the topical application of this composition to the skin, followed by rinsing with water.

Description

Title of the invention: Cosmetic composition in the form of a micro- or nano-emulsion rich in oil and its use for cleansing the human body. OBJECT OF THE INVENTION

[0001] The present invention relates to a cosmetic composition in the form of an oil-rich micro- or nano-emulsion, and to its cosmetic use for cleansing the human body, in particular as a shower oil or makeup remover oil. It also relates to a cosmetic method for cleansing the human body, comprising the topical application of this composition to the skin and / or hair, followed by rinsing with water. BACKGROUND OF THE INVENTION

[0002] Consumers of cosmetic products are increasingly aware of environmental and health issues and are therefore turning to products whose ingredients are as natural as possible, i.e. from bio-based raw materials.

[0003] Cleaning oils are not exempt from this quest for naturalness. They typically contain anionic surfactants as cleaning agents in the form of sulfated fatty alcohol ethoxylates, more specifically sodium salts (sodium laureth sulfate) or amine salts of these compounds. The latter, such as MIPA-laureth sulfate and TIPA-laureth sulfate, are preferred because they allow for the formulation of transparent and foaming compositions, generally in combination with laureth-2 or laureth-3 (CN116421504; FR 2 851 917; EP 1 955 690). However, due to the presence of ethoxylated groups in the structure of these surfactants, the NOI index of these products, which reflects their naturalness, is relatively high. In addition, the sulfate ions they contain are likely to cause skin irritation in people with sensitive skin.

[0004] There therefore remains a need for oil-based cleaning compositions containing a lower quantity of this type of surfactant. However, it has been observed that by reducing the amount of TIPA- or MIPA-laureth sulfate, the amount of foam produced when these oil-based compositions are mixed with water is insufficient. The present invention thus aims to overcome this drawback without negatively affecting the transparency or naturalness of the composition.

[0005] It has already been suggested in US-11,311,474 to replace TIPA-laureth sulfate with TIPA lauroyl sarcosinate and to substitute laureth-3 with a combination of lauryl alcohol and a nonionic surfactant (glyceryl monolaurate). and / or glyceryl lauryl ether). However, this solution impacts the cost of the formula and does not reduce the environmental footprint of amine salts, which are present at a level of 25 to 30% in these compositions.

[0006] The present invention aims to propose an alternative solution to achieve the aforementioned objectives. Summary of the invention

[0007] The invention thus relates to a cosmetic composition in the form of a micro- or nano-emulsion comprising:

[0008] (a) a first surfactant consisting of one or more amine salts of alcohol sulfate lauric (poly)ethoxylated,

[0009] (b) at least one second surfactant selected from non-lipophilic surfactants ionic,

[0010] (c) at least one linear fatty alcohol in Ci2-Ci6,

[0011] (d) of 30 to 85% by weight of oils, and

[0012] (e) of 0 to 10% by weight of water.

[0013] It also relates to the cosmetic use of this composition for cleaning the human body, in particular as a shower oil.

[0014] The invention also relates to a cosmetic method for cleansing the human body, comprising the topical application of this composition to the skin and / or hair, followed by rinsing with water. FIGURES

[0015] Figure 1 illustrates the height of foam obtained after mixing with water the compositions according to the invention and a comparative composition. DETAILED DESCRIPTION

[0016] It is understood that, in the remainder of this description, when ranges of values ​​are indicated, the bounds of these ranges are included.

[0017] In addition, the determinant "the" applied to each of the constituents of the composition designates both a single compound and a mixture of compounds when that constituent is formed from a mixture of compounds.

[0018] The present invention relates to a composition in the form of a micro- or nanoemulsion. By this expression, it is understood that the average number size of the oil droplets, as measured by dynamic light scattering using a Vasco particle size analyzer, is less than 300 nm, preferably between 10 and 150 nm and preferably between 20 and 100 nm.

[0019] This micro- or nano-emulsion is generally transparent (although it may include dyes), i.e., it exhibits a transmittance of at least 80% at a wavelength of 600 nm, for example measured using a UV- spectrometer visible Lambda 40, at a concentration of 0.5 wt% in water. It may, for example, have a transmittance of at least 90% or at least 95% at a wavelength of 600 nm, measured, for example, using a UV-visible Lambda 40 spectrometer. Alternatively, the micro- or nano-emulsion according to the invention may be translucent, that is, allow light to pass through without, however, clearly distinguishing the objects in front of which it is placed. In this case, it generally has a transmittance of less than 80%, but typically at least 50%, at a wavelength of 600 nm, as measured as described above.

[0020] The various constituents of the composition according to the invention will now be described in detail. Surfactants

[0021] The composition according to the invention comprises a first surfactant consisting of one or more amine salts of (poly)ethoxylated lauryl alcohol sulfate, containing in particular from 1 to 10 ethylene oxide groups, preferably from 1 to 5 ethylene oxide groups. Examples of such surfactants are mono-, di-, and trialcanolamine salts of (poly)ethoxylated lauryl alcohol sulfate, in particular MIPA-Laureth sulfate, TIPA-Laureth sulfate, and mixtures thereof.

[0022] TIPA-Laureth sulfate has the following structure:

[0023] [Chem.l]

[0024] The first surfactant may represent from 5 to 40% by weight, preferably from 7.5 to 35% by weight, and more preferably 10 to 30% by weight, relative to the total weight of the composition. However, it is preferable that it not represent more than 20% by weight, and preferably no more than 15% by weight, relative to the total weight of the composition, in order to optimize the naturalness of the latter.

[0025] The composition according to the invention further contains at least one second surfactant selected from among non-ionic lipophilic surfactants.

[0026] This second surfactant makes it possible to guarantee the transparency of the composition, that is to say to prevent the coalescence of the emulsion over time and / or under temperature conditions below 0°C, or even below -10°C, corresponding to certain transport conditions of cosmetic products intended for export.

[0027] The second surfactant is lipophilic, that is, generally chosen from among those having a hydrophilic / lipophilic balance (HLB) of less than 9, preferably less than 8, or even less than 6. By hydrophilic-lipophilic balance, we mean the equilibrium between the size and strength of the hydrophilic group and the size and strength of the lipophilic group of the amphiphilic surfactant. The term HLB is well known to those skilled in the art and is described, for example, in "The HLB System. A time-saving guide to Emulsifier Selection" (published by ICI Americas Inc.; 1984). The HLB of the surfactant(s) used according to the invention can be determined by the Griffin method at 25°C (J. Soc. Cosm. Chem. 1954 (volume 5), pages 249-256). Examples of surfactants with an HLB of less than 9 are cited in the reference work "McCutcheon's Emulsifiers & Detergents", International Edition of 2020 and subsequent editions.Refer to the document "Kirk-Othmer Encyclopedia of Chemical Technology", 2000, WILEY, for the definition of the properties and emulsifying functions of surfactants.

[0028] In a preferred embodiment of the invention, the second surfactant is selected from: lauryl alcohol and polyethylene glycol ethers; mono-, sesqui-, di- and triesters of sorbitan and saturated or unsaturated fatty acids, linear or branched, in Ci2-Ci8; mono- and diesters of polyglyceryl and saturated or unsaturated fatty acids, linear or branched, in Ci2-Ci8, possibly mono- or polyhydroxylated, containing 2 to 10 glycerol units; and mixtures thereof.

[0029] Examples of such surfactants are: laureth-2, laureth-3, laureth-4; sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan tristearate, sorbitan monooleate, sorbitan trioleate, sorbitan sesquioleate, sorbitan laurate, sorbitan stearate, sorbitan isostearate; Polyglyceryl-2 dipolyhydroxystearate, polyglyceryl-3 diisostearate, polyglyceryl-3 dioleate, polyglyceryl-4 oleate, polyglyceryl-6 dioleate, polyglyceryl-3 palmitate, polyglyceryl-4 laurate, polyglyceryl-10 laurate, polyglyceryl-6 distearate, polyglyceryl-10 stearate; and mixtures thereof. Also included are esterification products of waxes (particularly beeswax and / or jojoba wax) with polyglycerol.

[0030] Preferably, the second surfactant comprises laureth-3, laureth-2, a monoester of sorbitan and saturated or unsaturated fatty acid, linear or branched, in Ci2-Ci8, and mixtures thereof.

[0031] In the case where several non-ionic surfactants are used as a second surfactant, it is preferable that each of them has an HLB of less than 9, preferably less than 8, or in any case that the average HLB of this mixture of surfactants is less than 9, preferably less than 8.

[0032] The second surfactant advantageously represents 5 to 35%, preferably 10 to 30%, and more preferably 20 to 30%, of the weight of the composition.

[0033] The composition according to the invention may further comprise at least one third surfactant selected from among hydrophilic foaming surfactants, advantageously having an HLB greater than or equal to 11, more preferably between 13 and 15, and which may increase the volume of the foam and accelerate its formation. It may be an anionic surfactant, a nonionic surfactant, or a mixture thereof.

[0034] The third surfactant is distinct from the first and second surfactants and may in particular be selected from: C8-C20 fatty alkyl isethionate salts; C8-C20 fatty alkyl sarcosinate salts; C8-C20 fatty alkyl glutamate salts; C8-C20 carboxylic acid salts; alkyl polyglucosides; mono-, di- and trialcanalamides of linear or branched, saturated or unsaturated fatty acids, in C6-C20, such as mono- and diethanolamide of coconut fatty acids; esters of C8-C20 fatty acids and sucrose; and mixtures thereof. Preferably, the third surfactant is chosen from among the salts of fatty alkyl isethionates in C8-C20, polyglucosides and mixtures thereof.

[0035] The third surfactant, when present, advantageously does not include an oxyethylene moiety. It preferably represents 0.5 to 10% by weight, and more preferably 1 to 5% by weight, relative to the total weight of the composition. Fatty alcohols

[0036] The composition according to the invention contains at least one linear fatty alcohol in the form of C[2-Ci6], which surprisingly allows for a reduction in the level of sulfated and ethoxylated compounds in the composition, without negatively affecting the quantity and quality of the foam it produces. The fatty alcohol is advantageously chosen from lauric alcohol, myristic alcohol, and cetyl alcohol. Preferably, the fatty alcohol in the form of C[2-Ci6] comprises myristic alcohol, alone or in a mixture with lauric alcohol and / or cetyl alcohol.

[0037] The amount of fatty alcohol included in the composition according to the invention may represent from 0.1 to 10% by weight, preferably from 1 to 5% by weight, and more preferably from 1 to 3% by weight, relative to the total weight of the composition. Oils

[0038] For the purposes of the present invention, "oil" means a liquid compound at room temperature (25°C) and atmospheric pressure (105 Pa) which, when introduced at a concentration of at least 1% by weight into water at 25°C, is either completely insoluble in water or soluble to a degree of less than 10% by weight, relative to the weight of oil introduced into the water. Oils may be volatile or non-volatile. "Non-volatile oil" means a compound that is liquid at room temperature (25°C) and atmospheric pressure (105 Pa) and which, when introduced at a concentration of at least 1% by weight into water at 25°C, is either completely insoluble in water or soluble to a degree of less than 10% by weight, relative to the weight of oil introduced into the water. Oils may be volatile or non-volatile. "Volatile" in this description refers to an oil that remains on the skin at 25°C and atmospheric pressure for at least one hour, in the absence of friction, and / or has a vapor pressure of less than 0.001 mm Hg under these conditions. The oils included in the composition according to the invention may or may not be volatile; advantageously, they are non-volatile. Alternatively, it may be a mixture of non-volatile oils (predominant by weight) and volatile oils (minor by weight).

[0039] It is preferred that volatile and non-volatile oils be chosen from hydrocarbon oils, that is to say, that they contain exclusively atoms of carbon, hydrogen and possibly oxygen.

[0040] Examples of volatile oils include linear alkanes in C1 to C1, as well as essential oils.

[0041] Examples of non-volatile oils include: esters of acids and monoalcohols, such as the mixture of coco caprate and caprylate, shea butter ethyl ester, isostearyl isostearate, isononyl isononanoate, isopropyl myristate, ethylhexyl palmitate, hexyl laurate, and mixtures thereof; C6-Ci2 fatty acid triglycerides, such as the mixture of caprylic and capric triglycerides; branched and / or unsaturated fatty alcohols of the CiO-C2O type; hydrocarbons such as vegetable squalane extracted from olive oil; dialkyl carbonates, such as dicaprylyl carbonate and diethylhexyl carbonate; dialkyl ethers such as dicaprylyl ether; and mixtures thereof.

[0042] We can also mention vegetable oils which contain one or more of the aforementioned constituents, in particular wheat germ oil, sunflower oil, argan oil, hibiscus oil, coriander oil, grape seed oil, sesame oil, corn oil, apricot oil, castor oil, shea oil, avocado oil, olive oil, soybean oil, sweet almond oil, palm oil, rapeseed oil, cottonseed oil, hazelnut oil, macadamia oil, jojoba oil, alfalfa oil, pumpkin oil, rapeseed oil, blackcurrant oil, evening primrose oil, lavender oil, borage oil, millet oil, barley oil, quinoa oil, rye oil, safflower oil, candlenut oil, passionflower oil, rosehip oil or camellia oil.

[0043] According to the invention, it is preferable to use at least one oil chosen from among C6-Ci2 fatty acid triglycerides, vegetable oils, and mixtures thereof.

[0044]

[0045] The oils represent from 30 to 85% by weight, preferably from 30 to 60% by weight and more preferably from 35 to 50% by weight, relative to the total weight of the composition. Additional components

[0046] The composition according to the invention contains from 0 to 10% by weight of water, preferably from 0 to 5% by weight of water and, better still, from 0 to 2% by weight of water, which is generally supplied only by the raw materials used in this composition.

[0047] The composition according to the invention may also comprise at least one polyol selected from glycerin, propylene glycol, dipropylene glycol, butylene glycol, and mixtures thereof. It has been observed that these constituents allow adjustment of the viscosity of the composition and facilitate the incorporation of the third surfactant into the composition, as well as any hydrophilic active ingredients. The composition according to the invention thus advantageously exhibits a viscosity between 10 and 5000 mPa·s, preferably between 50 and 2000 mPa·s, as measured using a rheometer (such as a Brookfield viscometer) equipped with a spindle rotating at 10 rpm and resulting, under these conditions, in a shear force of 50 to 100 Pa·s (such as the Brookfield LV2 spindle). Glycerin is preferred, as this effect can be achieved using a smaller amount of polyol.Glycerin, alone or in combination with propylene glycol, is thus advantageously used according to the invention. The polyol preferably represents 1 to 15% by weight, and more preferably 5 to 10% by weight, relative to the total weight of the composition.

[0048] The composition according to the invention may thus contain one or more hydrophilic active ingredients, selected in particular from: zinc PCA, electrolytes, vitamins such as ascorbic acid and niacinamide, aqueous plant extracts, and mixtures thereof. Alternatively or in addition, it may also contain one or more lipophilic active ingredients, selected in particular from tocopherol and its esters; oily plant extracts, especially immortelle; and mixtures thereof.

[0049] This composition further advantageously contains less than 5% by weight of ethanol, preferably less than 1% by weight of ethanol, better, is free of ethanol.

[0050] The composition according to the invention may also include one or more other constituents chosen for example from: perfumes; antioxidants; colorants; and mixtures thereof.

[0051] In a preferred embodiment, the composition according to the invention contains at least 40% or even at least 60% of ingredients of natural origin, calculated in accordance with ISO 16128-2:2017, i.e. by multiplying the percentage of each of the ingredients present in the composition by its NOI index, determined according to this standard and which is between 0 and 1. Use

[0052] The composition according to the invention is adapted and intended to be used as a rinse-off product, in particular as a face and / or body cleansing product, in particular as a shower oil or makeup remover oil.

[0053] This product can be applied topically to any part of the body and in particular to the skin (including the face, hands and scalp) and / or hair, for the purpose of washing the skin and / or hair.

[0054] The invention therefore also relates to a cosmetic method for cleansing the human body, comprising the topical application to the skin and / or hair of the composition described above, followed by rinsing with water. EXAMPLES

[0055] The invention will be better understood in the light of the following examples, which are given purely for illustrative purposes and are not intended to limit the scope of the invention, as defined by the attached claims.

[0056] Example 1: Skin cleansing composition

[0057] The following composition was prepared from the constituents below (identified by their INCI names for those indicated in capital letters), used in the proportions below:

[0058] [Tables 1] Constituent % by weight TIPA LAURETH SULFATE 10-15% LAURETH-3 SORBITAN OLEATE Polyglycerol esters 20-30% DECYL GLUCOSIDE SODIUM COCOYL ISETHIONATE 2-5% Myristic alcohol 1-3% Polyols 10-14% Ethanol 0.1-1% Water 0-2% Preservative qs Fragrance qs Oils qsp 100%

[0059] The above composition was in the form of a transparent oily gel with a NOI of 64%. Once scooped into the palm of the hand and then applied to the body in the shower, it produced an abundant lather that was easily rinsed off. Example 2: Evaluation of foaming ability

[0060] The following compositions were prepared from the constituents below, used in the proportions indicated:

[0061] [Tables2] Constituent % by weight C Cl C2 C3 TIPA laureth sulfate 10% 10% 10% 10% Laureth-3 19% 19% 19% 19% Vegetable oil 71% 70% 70% 68% Lauryl alcohol (Cl2) — 1% — — Myristic alcohol (Cl4) — — 1% 3%

[0062] Three compositions according to the invention (Compositions Cl to C3) and a comparative composition (Composition C) were thus obtained.

[0063] 100g of each of the formulas C and C1-C3 of Example 1 were then mixed with 100g of distilled water in a 2 L beaker under stirring at 2000 rpm for 90 seconds. The height of the resulting foam was then measured.

[0064] The results of this test are illustrated in [Fig. 1]. As this Figure shows, fatty alcohol significantly increases foam height, even though these compositions contain only 10% TIPA laureth sulfate.

Claims

Demands

1. Cosmetic composition in the form of a micro- or nano-emulsion comprising: (a) a first surfactant consisting of one or more amine salts of (poly)ethoxylated lauryl alcohol sulfate, (b) at least one second surfactant selected from non-ionic lipophilic surfactants, (c) at least one linear fatty alcohol in the form of Ci2-Ci6, (d) 30 to 85% by weight of oils, and (e) 0 to 10% by weight of water.

2. Composition according to claim 1, characterized in that the amine salt of (poly)ethoxylated lauric alcohol sulfate is selected from mono-, di- and trialcanolamine salts of (poly)ethoxylated lauric alcohol sulfate, in particular from MIPA-Laureth sulfate, TIPA-Laureth sulfate and mixtures thereof.

3. Composition according to claim 1 or 2, characterized in that the second surfactant is selected from: lauryl alcohol and polyethylene glycol ethers; mono-, sesqui-, di- and triesters of sorbitan and saturated or unsaturated fatty acids, linear or branched, in Ci2-Ci8; mono- and diesters of polyglyceryl and saturated or unsaturated fatty acids, linear or branched, in Ci2-Ci8, optionally mono- or polyhydroxylated, containing from 2 to 10 glycerol units; and mixtures thereof, preferably the second surfactant comprises laureth-3, laureth-2, a monoester of sorbitan and saturated or unsaturated fatty acid, linear or branched, in Ci2-Ci8, and mixtures thereof.

4. Composition according to any one of claims 1 to 3, characterized in that it contains from 0 to 5% by weight of water and, preferably, from 0 to 2% by weight of water.

5. Composition according to any one of claims 1 to 4, characterized in that the fatty alcohol in Ci2-Ci6 is selected from lauric alcohol, myristic alcohol and cetyl alcohol, preferably the fatty alcohol in Ci2-Ci6 comprises myristic alcohol, alone or in mixture with lauric alcohol and / or cetyl alcohol.

6. A composition according to any one of claims 1 to 5, characterized in that it further contains at least one third surfactant selected from: C8-C2O fatty alkyl isethionate salts; C8-C2O fatty alkyl sarcosinate salts; salts of C8-C20 fatty alkyl glutamate; C8-C20 carboxylic acid salts; alkyl polyglucosides; mono-, di- and trialcanalamides of linear or branched fatty acids, saturated or unsaturated, of C6-C20, such as mono- and diethanolamide of coconut fatty acids; esters of C8-C20 fatty acids and sucrose; and mixtures thereof, preferably among C8-C20 fatty alkyl isethionate salts, polyglucosides and mixtures thereof.

7. Composition according to any one of claims 1 to 6, characterized in that it is transparent.

8. Composition according to any one of claims 1 to 7, characterized in that it further contains at least one polyol selected from: glycerin, propylene glycol, dipropylene glycol, butylene glycol and mixtures thereof.

9. Composition according to any one of claims 1 to 8, characterized in that it contains less than 5% by weight of ethanol, preferably less than 1% by weight of ethanol, better, is free of ethanol.

10. Cosmetic use of the composition according to any one of claims 1 to 9 for the cleansing of the human body, in particular as a shower oil or makeup remover oil.

11. A cosmetic method for cleansing the human body, comprising the topical application to the skin and / or hair of the composition according to any one of claims 1 to 9, followed by rinsing with water.

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