Biphasic composition with stable interface

Abstract

Biphasic composition with stable interface The present invention relates to a composition comprising an aqueous phase and an oily phase which are separate, characterized in that the oily phase comprises squalane, dicaprylyl ether and a mixture of linear or branched alkane having from 15 to 19 carbon atoms, said composition being substantially free from surfactants and from silicones. It also relates to associated methods and cosmetic uses.

Description

[0001] Biphasic composition with stable interface

[0002] The present invention relates to a biphasic composition consisting of an aqueous phase and an oily phase which are separate, the oily phase comprising specific oils. The present invention also relates to the use of such a composition, as well as to a care method using such a composition.

[0003] Compositions consisting of two separate phases, particularly an aqueous phase and an oily phase which are separate and are not emulsified in each other at rest, are generally referred to as “biphasic composition.” They differ from emulsions by the fact that, at rest, the two phases are separate instead of being emulsified in each other. The use of these biphasic compositions requires prior stirring in order to form an emulsion, the latter needing to be of sufficient quality and stability to allow for a homogeneous application of both phases on the skin or the keratin material to which it is applied. At rest, said phases must separate quickly from each other and return to their initial state, this phenomenon being more commonly known by the term “phase separation” or “demixing.”

[0004] Relatively rapid demixing of the two phases after their use is one of the desired qualities of biphasic compositions. Indeed, achieving a rapid phase separation is desirable for various reasons, particularly because a poor separation of the two phases is perceived as unsightly by users and may cause the product to become “triphasic” as it is used over time.

[0005] Furthermore, commercial biphasic compositions are in particular used for care.

[0006] However, biphasic compositions usually have greasy sensory properties and relatively unstable interfaces after stirring (turbidities, spiral formation, etc.).

[0007] Moreover, the formulation of environmentally-friendly cosmetic products, i.e. those whose design and development take account of environmental issues, is becoming a major concern in helping to meet global challenges.

[0008] It has therefore become essential to propose more sustainable compositions and / or preparation processes and / or ingredients to meet these environmental challenges.

[0009] Consequently, there remains a need for novel biphasic compositions consisting of two separate, non-miscible phases that simultaneously have a light texture, non-greasy sensory properties, and good demixing qualities, while still achieving effective care. There is also a need for biphasic compositions having a clear and stable interface after stirring (i.e. no turbidity or spiral formation).

[0010] Moreover, it is important to develop novel cosmetic compositions with a better carbon footprint in particular by promoting the use of raw materials that are renewable and / or have a good wilderness quality index and / or are of natural origin and more particularly of plant origin while reducing the use of compounds of petrochemical origin.

[0011] The inventors surprisingly discovered that the ternary association of squalane, dicaprylyl ether and linear or branched alkanes having from 15 to 19 carbon atoms, in specific proportions, coupled with an aqueous phase, makes it possible to obtain a biphasic composition that meets these needs. The compositions according to the invention have in particular a light texture, non-greasy sensory properties, good demixing qualities, a clear and stable interface after stirring, and provide effective care.

[0012] More specifically, the present invention relates to a composition, preferably a care composition, comprising an aqueous phase and an oily phase which are separate, wherein the oily phase comprises squalane, dicaprylyl ether and a mixture of linear or branched alkane having from 15 to 19 carbon atoms, said composition being substantially free from surfactants and from silicones.

[0013] Such a composition according to the invention is a biphasic composition.

[0014] The expression “biphasic composition” refers to a composition that is made of up two separate phases, one an aqueous phase and one an oily phase, which require prior stirring to form an emulsion before application.

[0015] Preferably, the biphasic composition according to the invention comprises the aqueous phase and the oily phase in a weight ratio of between 70: 30 and 98: 2 respectively, and preferably between 75: 25 and 95: 5, preferably around 90: 10, respectively.

[0016] These ratio values make it possible to obtain a biphasic composition that particularly has a satisfactory visual appearance.

[0017] All compositions according to this invention are cosmetic compositions. “Cosmetic” means a composition compatible with the skin, mucous membranes and / or skin appendages. The biphasic composition according to the invention is substantially free from surfactants. It is also substantially free from silicones. A composition that is “substantially free from surfactants” means that this composition comprises less than 0.5% by weight of surfactants with respect to the total weight of the composition, preferably less than 0.3% by weight, preferably less than 0.1% by weight. Preferably, the biphasic composition according to the invention is totally free from surfactants. Preferably, the biphasic composition according to the invention is substantially free from non-ionic surfactants, preferably totally free from non-ionic surfactants. Preferably, the biphasic composition according to the invention is substantially free from non-ionic surfactants chosen from polysorbates and polyglycerol esters (in particular polyglyceryl-3 diisostearate and polyglyceryl-6 oleate), preferably totally free from non-ionic surfactants chosen from polysorbates and polyglycerol esters.

[0018] A composition that is “substantially free from silicones" means that the composition comprises less than 1% by weight of silicones with respect to the total weight of the composition, preferably less than 0.5% by weight, preferably less than 0.3% by weight, preferably less than 0.1% by weight. Preferably, the biphasic composition according to the invention is totally free from silicones.

[0019] Oily phase

[0020] The biphasic composition according to the invention comprises an oily phase comprising at least squalane, dicaprylyl ether and a mixture of linear or branched alkanes having from 15 to 19 carbon atoms.

[0021] Said oily phase is liquid at ambient temperature (20-25°C).

[0022] The concentration of the oily phase varies preferably from 2 to 30% by weight, preferably from 2 to 25% by weight, preferably from 5% to 20% by weight, preferably from 5% to 15% by weight, with respect to the total weight of the biphasic composition.

[0023] Preferably, the concentration of the oily phase is approximately 10% by weight with respect to the total weight of the biphasic composition.

[0024] Squalane

[0025] Squalane (C30H62, chemical name 2,6,10,15,19,23-hexamethyltetracosane) is a saturated hydrocarbon composed of a chain of 30 saturated carbon atoms of the following formula: [Chem 1 ]

[0026] It is obtained by hydrogenating squalene (C30H50). Originally, squalene was extracted from shark liver oil. Squalane, given its saturated chemical structure, is much more stable than squalene which is very readily peroxidized.

[0027] The squalane used in the invention is preferably of plant origin. Preferably, the squalane is sourced from plant oils, preferably olive oil, wheat germ oil, bran oil, rice oil or olive starches.

[0028] Preferably, in the present invention, the squalane is extracted from olive oil.

[0029] For example, the product marketed under the name Neossance Squalane by Amyris will be used.

[0030] Preferably, the biphasic composition according to the invention comprises from 45% to 80% by weight of squalane with respect to the total weight of oily phase. Preferably, the biphasic composition according to the invention comprises from 50% to 75% by weight of squalane with respect to the total weight of oily phase, preferably from 55% to 70% by weight, preferably from 60% to 70% by weight.

[0031] Dicaprylyl ether

[0032] Dicaprylyl ether (or di-n-octyl ether) is a hydrocarbon oil derived from fatty acids of plant origin, such as those of coconut.

[0033] It is in particular marketed by Cognis under the name Cetiol OE, or by Ecogreen under the name Rofetan OE.

[0034] Preferably, the biphasic composition according to the invention comprises from 5% to 30% by weight of dicaprylyl ether with respect to the total weight of oily phase. Preferably, the biphasic composition comprises from 5% to 25% by weight of dicaprylyl ether with respect to the total weight of oily phase, preferably from 10% to 20% by weight, preferably from 13% to 17% by weight.

[0035] Linear or branched alkanes having from 15 to 19 carbon atoms The composition according to the present invention further comprises a mixture of linear or branched alkanes having from 15 to 19 carbon atoms.

[0036] As an example of alkanes suitable for the invention, mention may be made of mixtures of alkanes having from 15 and 19 carbon atoms with a molecular weight of between 200 g / mol and 250 g / mol.

[0037] Preferably, the alkanes are branched.

[0038] Preferably, the alkanes are of plant origin.

[0039] Preferably, the mixture used comprises 95 to 99% of C15-C19 branched alkanes by weight with respect to the total weight of the mixture, and 1 to 5% by weight of C12-C14 and C20-C26 alkanes with respect to the total weight of the mixture. Such a mixture preferably has a molecular weight of about 216 g / mol. Such a mixture is marketed by Seppic under the reference Emogreen L15.

[0040] Alternatively and preferably, the mixture used comprises 95 to 99% of the mixture of C15-C19 branched alkanes by weight with respect to the total weight of the mixture, and 1 to 5% of C12-C14 and C20-C26 alkanes by weight with respect to the total weight of the mixture. Such a mixture preferably has a molecular weight of about 248 g / mol. Such a mixture is marketed by Seppic under the reference Emogreen L19.

[0041] Alternatively, a mixture is used comprising 10% by weight of C15-C19 branched alkanes with respect to the total weight of the mixture, and 1 to 5% by weight of C12-C14 and C20-C26 alkanes with respect to the total weight of the mixture. Such a mixture is marketed by Seppic under the reference Emosmart L19.

[0042] Preferably, the biphasic composition according to the invention comprises from 5% to 30% by weight of mixture of linear or branched alkanes having from 15 to 19 carbon atoms with respect to the total weight of oily phase. Preferably, the biphasic composition according to the invention comprises from 5% to 25% by weight of mixture of linear or branched alkanes having from 15 to 19 carbon atoms with respect to the total weight of oily phase, preferably from 10% to 20% by weight, preferably from 13% to 17% by weight.

[0043] Aqueous phase

[0044] The biphasic composition according to the invention comprises at least one aqueous phase, which preferably comprises at least water. The aqueous phase optionally contains at least one organic solvent that is soluble or miscible in water at 25°C.

[0045] The water-soluble or water-miscible solvents suitable for the invention comprise short-chain linear or branched alkanols for example at C2-C4, such as ethanol, isopropanol, propanol or butanol; diols or polyols having in particular from 2 to 20 carbon atoms, preferably from 2 to 6 carbon atoms, such as glycerol, ethylene glycol, 1 ,2-propylene glycol, 1 ,3-butylene glycol, pentylene glycol, hexylene glycol, diethylene glycol, 1 ,3-propanediol, 1 ,2-pentadiol, dipropylene glycol, 2-ethoxyethanol, diethylene glycol monomethylether, triethylene glycol monomethylether, sorbitol, polyethylene glycols having from 2 to 200 ethylene oxide units and mixtures thereof.

[0046] In particular ethanol, 1 ,3-butylene glycol, pentylene glycol and / or propylene glycol will be used.

[0047] Preferably, the water-soluble or water-miscible solvents are present at a content of at least 2% by weight with respect to the total weight of aqueous phase, preferably at least 3% by weight, preferably at least 5% by weight, preferably at least 6% by weight, preferably at least 8% by weight.

[0048] Preferably, the aqueous phase comprises at least 60% by weight of water with respect to the total weight of aqueous phase, preferably at least 70% by weight, preferably between 80% and 98% by weight.

[0049] The concentration of the aqueous phase varies preferably from 70 to 98% by weight, preferably from 75% to 98% by weight, preferably from 80% to 95% by weight, preferably from 85 to 95% by weight, with respect to the total weight of the biphasic composition.

[0050] The aqueous phase and / or the oily phase may further comprise conventional cosmetic active agents and / or additives, such as electrolytes, chelating agents, perfumes and / or preservatives.

[0051] Among the active agents, mention may be made of hydrophilic active agents and lipophilic active agents. As active agents, mention may be made of niacinamide, plant extracts, adenosine and vitamins, their precursors or derivatives. The plant extracts may be hydrophilic or lipophilic. As vitamins, their precursors or derivatives, mention may be made of panthenol or tocopherol. Preferably, the biphasic composition according to the invention comprises at least niacinamide. The electrolyte may be chosen from sodium chloride or sodium sulfate.

[0052] The electrolyte is preferably sodium chloride.

[0053] Preferably, the active substance content of electrolyte(s) is between 0.1% and 5% by weight with respect to the total weight of aqueous phase, preferably between 0.1 % and 2% by weight, preferably between 0.2% and 1% by weight.

[0054] The present invention also relates to a method for the care of keratin materials comprising the application of a biphasic composition according to the invention on said keratin materials, in particular the skin and / or hair.

[0055] This invention also relates to a cosmetic method for the treatment and / or care of human keratin materials, preferably of the skin, comprising stirring of a biphasic composition according to the invention, then its application on the surface of said keratin materials.

[0056] The invention also relates to the use of a biphasic composition according to the invention for the care of keratin materials, in particular of the skin, mucous membranes and / or hair.

[0057] “Human keratin materials” refers to the skin (body, face, eye contour), hair, eyelashes, eyebrows, body hair, nails, lips and mucous membranes.

[0058] The expressions “between ... and “ranging from ... to ...” and “varies from ... to ...” are to be understood to be inclusive of the limits, unless specified otherwise.

[0059] Concrete, yet non-limiting, examples, illustrating the invention, will now be provided.

[0060] In the examples, the pressure is the atmospheric pressure, unless stated otherwise. The percentages are given by weight, unless stated otherwise.

[0061] Examples

[0062] Example 1 : preparation of a biphasic composition according to the invention

[0063] A biphasic composition according to the invention is prepared according to the method hereinafter. It is composed of 90% by weight of a composition C1 (i.e. aqueous phase), and 10% by weight of composition C2 (i.e. oily phase). The preparation method is as follows:

[0064] Composition C1 is prepared by heating the water and glycols of phase A1 to 60°C. The preservatives are dissolved and the remaining ingredients of A1 are introduced. The phase obtained is diluted with the water from A2 and cooled, and the other ingredients of B, C, E are then introduced and cold homogenized. The niacinamide (F) is solubilized at the end of manufacture, before adding ethanol (G). The aqueous phase obtained is filtered at the end of manufacture on a 5pm filter.

[0065] The ingredients of the oily phase C2 are cold homogenized, with an all-in-one method. The oily phase obtained is filtered at the end of manufacture on a 50pm filter.

[0066] Finally, 90% by weight of composition C1 is mixed with 10% by weight of composition C2.

[0067] Composition C1 - aqueous phase: [T able 1 ] '

[0068] Composition C2 - oily phase: [Table 2]

[0069] The biphasic composition obtained contains raw materials with a good wilderness quality index and / or of natural origin and particularly of plant origin.

[0070] Example 2: evaluation of the composition according to the invention

[0071] The biphasic composition according to the invention of example 1 was tested.

[0072] Stirring and stability test:

[0073] A test of stirring and stability over time was carried out in order to study the stability of the biphasic composition after stirring.

[0074] The stability of the biphasic composition after stirring proved to be excellent: no turbidity at the interface is visible, no spiral formation after demixing the two phases.

[0075] Consumer test:

[0076] A consumer test was carried out in order to study the texture and sensory properties of the biphasic composition.

[0077] For 4 weeks, 62 women applied the biphasic composition on their skin. They then determined whether the composition had a non-greasy / non-oily or light finish on the skin after application, by responding either “agree”, or “somewhat agree”.

[0078] [Table 3]

[0079] In total, 98.4% of the women found that the texture was not greasy / oily after application, and that the skin finish was light.

[0080] Example 3: preparation of comparative biphasic compositions Comparative biphasic compositions were prepared according to the method of example 1 :

[0081] They are composed of 90% by weight of the composition C1 (i.e. aqueous phase) according to T able 1 of example 1 , and 10% by weight of composition C2a, C2b or C2c (i.e. oily phase) detailed in Table 4.

[0082] Comparative compositions C2a, C2b and C2c (and composition C2 of example 1 according to the invention)- oily phase:

[0083] [Table 4]

[0084] Example 4: evaluation of the comparative compositions and of the biphasic composition of example 1

[0085] The comparative biphasic compositions of example 3 were tested, and compared to the composition of example 1 according to the invention.

[0086] Stirring and stability test:

[0087] A test of stirring and stability over time was carried out in order to study the stability of each biphasic composition after stirring. The following scores were awarded on the basis of the obtained stability results:

[0088] > 1 : Quick and well demix / clear interface

[0089] > 0: Less quick and less well demix / turbid and unclear interface

[0090] [Table 5]

[0091] Sensory test:

[0092] A test was carried out in order to study the texture and sensory properties of the biphasic compositions.

[0093] The composition was evaluated according to the following parameters: pleasant to apply (roundess on application) and had a good finish on the skin after application, by scoring the results between 1 and 4 as follows:

[0094] > 1 : Texture : very dry / Application : no roundness / Finish on skin : matte

[0095] > 2: Texture : dry finish / Application : not enough roundness / Finish on skin : matte and not enough glowy

[0096] _3: Texture : non-oily / non-greasy / Application : roundness / Finish on skin : light and glowy

[0097] > 4: Texture : too greasy / Application : too much roundness / Finish on skin : very shiny finish.

[0098] [Table 6] Only biphasic composition comprising composition C1 and composition C2, according to the invention, exhibited excellent demixing properties, as well as a texture that was not greasy / oily after application, and that left the skin with a light and glowy finish.

Claims

CLAIMS1. Composition comprising an aqueous phase and an oily phase which are separate, characterized in that the oily phase comprises squalane, dicaprylyl ether and a mixture of linear or branched alkane having from 15 to 19 carbon atoms, said composition being substantially free from surfactants and from silicones.

2. Composition according to claim 1 , which is a biphasic composition.

3. Composition according to claim 1 or 2, characterized in that it comprises the aqueous phase and the oily phase in a weight ratio of between 70: 30 and 98: 2 respectively, and preferably between 75: 25 and 95: 5.

4. Composition according to one of the preceding claims, characterized in that it comprises the aqueous phase and the oily phase in a weight ratio of approximately 90: 10, respectively.

5. Composition according to one of the preceding claims, which comprises from 45% to 80% by weight of squalane with respect to the total weight of oily phase, preferably from 50% to 75% by weight, preferably from 55% to 70% by weight, preferably from 60% to 70% by weight.

6. Composition according to one of the preceding claims, which comprises from 5% to 30% by weight of dicaprylyl ether with respect to the total weight of oily phase, preferably from 5% to 25% by weight, preferably from 10% to 20% by weight, preferably from 13% to 17%.

7. Composition according to one of the preceding claims, which comprises from 5% to 30% by weight of mixture of linear or branched alkanes having from 15 to 19 carbon atoms with respect to the total weight of oily phase, preferably from 5% to 25% by weight, preferably from 10% to 20% by weight, preferably from 13% to 17%.

8. Composition according to one of the preceding claims, wherein the aqueous phase comprises at least water.

9. Composition according to one of the preceding claims, wherein the aqueous phase comprises at least one organic solvent soluble or miscible in water at 25°C; preferably the solvent is chosen from short-chain linear or branched alkanols for exampleat C2-C4, such as ethanol, isopropanol, propanol or butanol; diols or polyols having in particular from 2 to 20 carbon atoms, preferably from 2 to 6 carbon atoms, such as glycerol, ethylene glycol, 1 ,2-propylene glycol, 1 ,3-butylene glycol, pentylene glycol, hexylene glycol, diethylene glycol, 1 ,3-propanediol, 1 ,2-pentadiol, dipropylene glycol, 2-ethoxyethanol, diethylene glycol monomethylether, triethylene glycol monomethylether, sorbitol, polyethylene glycols having from 2 to 200 ethylene oxide units and mixtures thereof.

10. Composition according to one of the preceding claims, wherein the aqueous phase comprises at least 60% by weight of water with respect to the total weight of aqueous phase, preferably at least 70% by weight, preferably between 80% and 98% by weight.

11. Composition according to one of the preceding claims, which comprises less than 0.5% by weight of surfactants with respect to the total weight of the composition, preferably less than 0.3% by weight, preferably less than 0.1 % by weight and which comprises less than 1% by weight of silicones with respect to the total weight of the composition, preferably less than 0.5% by weight, preferably less than 0.3% by weight, preferably less than 0.1% by weight; preferably, the biphasic composition according to the invention is totally free from surfactants and from silicones.

12. Composition according to one of the preceding claims, comprising at least one active agent chosen from hydrophilic active agents and lipophilic active agents, preferably from niacinamide, plant extracts, adenosine and vitamins, their precursors or derivatives, preferably at least niacinamide.

13. Method for the care of keratin materials comprising the application of a composition according to one of claims 1 to 12 on said keratin materials.

14. Use of a composition according to one of claims 1 to 12, for the care of keratin materials, in particular of the skin, mucous membranes and / or hair.

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