PERSONAL CARE COMPOSITION WITH VISUALLY DISTINCT AQUEOUS AND OILY PHASES

Abstract

A multiphase personal care composition is described comprising an aqueous phase and an oily phase comprising volatile silicone, fatty acid amide and retinoid, wherein the aqueous phase is visually distinct from, and in physical contact with, the oily phase.

Description

PERSONAL CARE COMPOSITION WITH VISUALLY DISTINCT AQUEOUS AND OILY PHASES FIELD OF INVENTION The present invention relates to a multiphase personal care composition. In particular, the present invention relates to a multiphase personal care composition comprising an aqueous phase and an oily phase comprising a volatile silicone and a retinoid, wherein the composition comprises fatty acid amide and the aqueous phase is visually distinct from, and in physical contact with, the oily phase. BACKGROUND OF THE INVENTION Retinoids (e.g., retinol and retinyl esters) are common ingredients used in personal care products. Retinol (vitamin A) is an endogenous compound naturally produced in the human body and is essential for the normal differentiation of epithelial cells. Natural and synthetic derivatives of vitamin A have been widely used in the treatment of various skin disorders and as skin repair or renewal agents. Retinoic acid has been used to treat a variety of skin conditions, including acne, wrinkles, psoriasis, age spots, and discoloration. Instability is sometimes a problem for retinoids, usually resulting from oxidation in situ. This can lead to a product that develops an unpleasant odor and / or discoloration. It could even result in an unstable composition with oxidized compounds that don't necessarily have a positive impact on the skin. There is growing interest in developing a stable skin formulation containing retinoids. A multiphase formulation is one solution. By including the retinoid in the oil phase, oxidation can be reduced. However, when we developed a multi-phase personal care formulation, it was unexpectedly found to cause skin sensitization in consumers within 24 hours. We have recognized that there remains a need to develop a multi-phase personal care formulation containing retinoids but with less or no sensitization. Surprisingly, skin sensitization was found to be significantly reduced by including volatile silicone in the multi-phase personal care formulation. BRIEF DESCRIPTION OF THE INVENTION In a first aspect, the present invention is directed to a multiphase personal care composition comprising an aqueous phase, and an oily phase comprising volatile silicone and retinoid, wherein the composition comprises fatty acid amide and the aqueous phase is visually distinct from, and in physical contact with, the oily phase. In a second aspect, the present invention is directed to the kit of parts comprising a cosmetic container, a multi-phase composition for personal care of the present invention, and instructions for the use of the kit. In a third aspect, the present invention is directed to a method for preparing a personal care product comprising the step of shaking a cosmetic container containing a multiphase personal care composition of the present invention by hand. In a fourth aspect, the present invention relates to a method for providing skin lightening to the skin of an individual comprising the steps of (i) shaking a cosmetic container containing a composition of any of claims 1 to 10 with the human hand and (ii) applying the resulting product topically. All other aspects of the present invention will become more evident upon consideration of the detailed description and examples that follow. DETAILED DESCRIPTION OF THE INVENTION Except in the examples, or where explicitly stated otherwise, all numbers in this description that indicate quantities of material or reaction conditions, physical properties of materials and / or optional use may be understood as modified by the word "approximately". All quantities are by weight of the composition, unless otherwise specified. It should be noted that, when specifying any variation of values, any particular upper value can be associated with any particular lower value. To avoid any ambiguity, the phrase "comprising" is intended to mean "including" but not necessarily "consisting of" or "composed of." In other words, the listed steps or options need not be exhaustive. It should be considered that the description of the invention found herein covers all the embodiments found in the claims as multiple dependencies on each other, regardless of the fact that the claims can be found without multiple dependency or redundancy. When a feature is described with respect to a particular aspect of the invention (e.g., a composition of the invention), such description shall be deemed to apply also to any other aspect of the invention (e.g., a method of the invention) mutatis mutandis. “Visually distinct”, as used herein, relates to the regions occupied by each phase that the human eye can see separately as clearly separated regions in contact with each other (i.e., they are not emulsions or dispersions in particles smaller than 100 microns). “Multiphase”, as used herein, relates to at least two phases that occupy separate and distinct physical spaces within the container in which they are stored, although they are in direct contact with each other (i.e., they are not separated by a barrier). “Transparent” as used herein, relates to at least 70%, preferably at least 80%, more preferably at least 85% of the light, having a wavelength of 550 nm, transmitted by a 1 cm thick sample, measured by a UV-vis spectrometer (e.g., Perkin-Elmer Lambda 650S) at 25°C. “Opaque” as used herein, relates to no more than 50%, preferably no more than 30% of the light transmitted by the same method. “Viscosity,” as used herein, means kinematic viscosity at 25°C and is reported as centistokes (1 cSt = 1 mm² s⁻¹). The viscosity of fluids such as silicone can be determined, for example, by the relevant international standard, such as ISO 3104. preference from 0.1 cSt to 20 cSt, higher preference from 0.2 to 10 cSt. The preferred volatile silicone is cyclopentasiloxane. The preferred volatile silicone is selected from octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, heptamethylhexyltrisiloxane, heptamethyloctyltrisiloxane, hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, dodecamethylpentasiloxane, or a mixture thereof. Most preferably, the volatile silicone is selected from decamethylcyclopentasiloxane or dodecamethylcyclohexasiloxane. Most preferably, the volatile silicone is decamethylcyclopentasiloxane. Examples of commercially available silicone include silicone with grade designations 344, 345, 244, 245, and 246 from Dow Corning Corporation; Silicone 7207 and Silicone 7158 from Union Carbide Corporation; and SF1202 from General Electric. The preferred amount of volatile silicone ranges from 3 to 60%, with 8 to 55% being the most preferred, 15 to 50% even more preferred, 25 to 45% still more preferred, and 28 to 42% by weight of the total composition. The preferred amount of volatile silicone ranges from 10 to 98%, with 25 to 95% being the most preferred, 35 to 92% even more preferred, 45 to 80% still more preferred, and 55 to 75% by weight of the total oil phase. Preferably, the weight ratio of volatile silicone to retinoid is 10:1 to 1000:1, more preferably 20:1 to 500:1 and with maximum preference 50:1 to 300:1. Preferably, the composition comprises a nonionic surfactant. Preferably, the nonionic surfactant comprises: a) condensation products of aliphatic alcohols having 8 to 22 carbon atoms in a linear or branched chain configuration with ethylene oxide, such as coconut alcohol / ethylene oxide condensates having 2 to 15 moles of ethylene oxide per mole of coconut alcohol; b) condensates of alkylphenols having C6-C24 alkyl groups with 5 to 25 moles of ethylene oxide per mole of alkylphenol; c) fatty acid esters of polyoxyethylsorbitan, for example, C6-C24 polyoxyethylsorbitan fatty acid esters; d) an alkyl glucoside, or a mixture thereof. More preferably, the nonionic surfactant is an alkyl glucoside. The alkyl glucoside as used herein includes alkyl polyglucosides. The preferred alkyl glucoside is represented by the formula RO-(G)n, where R is a linear or branched chain alkyl group that may be saturated or unsaturated, G is a saccharide group and the degree of polymerization, n, may have a value from 1 to 10; preferably, R has an average alkyl chain length of C5 to C20, G is selected from monosaccharide residues Cs or Ce and n has a value from 1 to 6; more preferably, R has an average alkyl chain length of Ce to Cie, G is glucose and n has a value from 1 to 6. Preferably, the amount of non-ionic surfactant is from 0.0001 to 15%, more preferably from 0.001 to 10%, even more preferably from 0.01 to 6%, even more preferably from 0.1 to 5%, and with the highest preference from 1 to 4% by weight of the composition. Preferably, the composition comprises fatty acid amides. Preferably, the fatty acid amides contain at least 6 carbon atoms. Suitable fatty acids include saturated and unsaturated, linear or branched fatty acids. Preferably, suitable fatty acids contain 8 IVIA / a / ZUZZ / U 14U I ua 24 carbon atoms, preferably from 12 to 20 carbon atoms, and more preferably from 12 to 18 carbon atoms, because longer-chain fatty acid amides are more beneficial for skin conditioning. In the most preferred embodiment of the invention, essential fatty acid amides are employed because essential fatty acids provide nutrition for the skin. Examples of essential fatty acids include, but are not limited to, linoleic, linolenic, arachidonic, gamma-linolenic, homo-gamma-linolenic, and mixtures thereof. Linoleic acid is the most preferred because it is also a precursor of ceramide. The amides suitable for use in the present invention may be simple amides (i.e., those containing a -CONH2 group), N-alkylamides, N,N-dialkylamides, mono-alkanolamides, and di-alkanolamides. The suitable alkyl or alkanol groups contain from 1 to 30 carbon atoms, preferably from 1 to 20 carbon atoms, and most preferably from 1 to 8 carbon atoms. The preferred amides included in the present invention are mono- and di-alkanolamides, particularly of essential fatty acids. Alkanolamides are more readily available than alkylamides. The preferred fatty acid amides are selected from mono- and di-ethanolamides of linoleic acid, palmitic acid, and coconut oil. Fatty acid amide may be included in an amount ranging from 0.0001% to 10%, preferably from 0.01% to 4%, more preferably from 0.1% to 1% by weight of the total amount of the composition. Preferably, the composition comprises triglycerides. More preferably, the composition comprises caprylic / capric triglyceride, coconut oil, sunflower seed oil, safflower oil, cottonseed oil, olive oil, or a mixture thereof. Caprylic / capric triglyceride is particularly preferred. Preferably, the amount of triglycerides is from 0.001 to 12%, more preferably from 0.1 to 8%, and even more preferably from 0.5 to 5% by weight of the composition. Preferably, the composition comprises polyhydric alcohols. The polyhydric alcohols may be selected from the group of propylene glycol, dipropylene glycol, polypropylene glycol, polyethylene glycol, sorbitol, hydroxypropylsorbitol, hexylene glycol, 1,3-butylene glycol, isoprene glycol, ethoxylated glycerol, propoxylated glycerol, or a mixture thereof. The most preferred polyhydric alcohol is glycerol, also known as glycerin. The amount of polyhydric alcohol may vary from 5 to 35%, preferably from 8 to 25%, and most preferably from 12 to 18% by weight of the composition. The composition may comprise water in an amount of 10 to 90% by weight of the composition, more preferably 15 to 78%, even more preferably 20 to 65%, more preferably 25 to 50% by weight of the composition. The composition may comprise a resorcinol derivative. The resorcinol derivative preferably refers to the fact that at least one hydrogen atom in the ring structure and / or in a hydroxyl group of resorcinol is replaced with an alkyl or phenylalkyl group. Preferably, the resorcinol derivative is 4-substituted resorcinol. Preferably, the resorcinol derivative is selected from 4-ethylresorcinol, 4-butylresorcinol, 4-hexylresorcinol, phenylethylresorcinol, or a mixture thereof, and most preferably, the resorcinol derivative comprises 4-hexylresorcinol. The preferred amount of resorcinol derivative is in the range of 0.00001 to 10%. MA / a / ZUZZ / UI 4U I u greater preference from 0.001 to 5% and with the maximum preference from 0.1 to 0.6% by weight of the total amount of the composition. The composition may include optional ingredients including a moisturizing agent, a skin-brightening agent, preservatives, antioxidants, colorants, fragrances, or a combination thereof. Vitamin B3 compounds (including vitamin B3 derivatives), for example niacin, nicotinic acid or niacinamide, are the preferred skin-lightening agents according to the Invention, niacinamide being the most preferred. Preferably, the composition is a two-phase liquid. Preferably, both the aqueous and oil phases are transparent. Preferably, the weight ratio of the aqueous to the oil phase is between 1:8 and 8:1, preferably between 1:4 and 4:1, and even more preferably between 1:2 and 2:1. The multi-phase personal care composition can be provided to a consumer in any suitable form, but it is preferable that the composition be provided within a cosmetic container. The preferred cosmetic container has a volume of 2 to 250 mL, a more preferred volume of 5 to 100 mL, an even more preferred volume of 8 to 60 mL, and a still more preferred volume of 10 to 50 mL. Preferably, a kit comprises a cosmetic container, a multiphase personal care composition according to the invention, and instructions for use of the kit. Preferably, the instructions include the step of mixing the aqueous phase with the oil phase in any suitable manner, for example, by shaking the container by hand for at least 1 second, preferably from 2 seconds to 5 minutes, and more preferably from 3 seconds to 1 minute. In this way, a homogeneous personal care product is formed. Preferably, the personal care product is opaque. Ideally, the multi-phase personal care composition is capable of generating a personal care product by shaking the cosmetic container by hand, preferably for 1 second to 5 minutes, more preferably 1 second to 1 minute. Ideally, the personal care product is capable of recovering into a multi-phase personal care composition by standing for 3 minutes to 20 hours, more preferably 10 minutes to 7 hours, and even more preferably 15 minutes to 4 hours. Preferably, the personal care composition (product) is a skin care composition (product). The skin care composition (product) relates to a composition (product) suitable for topical application to human skin, preferably a leave-on product. The term “leave-on,” as used with reference to the compositions herein, means a composition that is applied or rubbed onto the skin and left on the skin. The term “skin,” as used herein, includes the skin of the face (excluding the eyelids and lips), neck, chest, abdomen, back, arms, armpits, hands, and legs. Preferably, “skin” means the skin of the face (excluding the eyelids and lips) and armpits; more preferably, “skin” means the skin of the face other than the lips and eyelids. The following examples are provided to facilitate understanding of the invention. The examples are not intended to limit the scope of the claims. Examples Example 1 This example demonstrates the preparation of a multi-phase composition for skin care. IVIA / a / ZUZZ / U 14U I u Table 1 Phase Ingredient Samples (% by weight) A 1 2 Aqueous Water up to 100 up to 100 up to 100 Glycerin 15.00 15.00 15.00 Cocamide MEA 0.25 0.25 0.25 Caprylyl / Caprylyl Glucoside 1.24 1.24 1.24 Niacinamide 3.00 3.00 3.00 Disodium EDTA 0.05 0.05 0.05 Preservative 0.66 0.66 0.66 Sodium Chloride 0.60 0.60 0.60 Dye 0.00151 0.00151 0.00151 Oily Decamethylcyclopentasiloxane - - 38.57 Isohexadecane 38.57 29.10 - Myristate Isopropyl acetate - 9.47 - Tocopheryl acetate 1.00 1.00 1.00 Retinyl propionate 0.33 0.33 0.33 Fragrance 0.10 0.10 0.10 Colorant 0.0003 0.0003 0.0003 The level of the ingredients refers to the level of the active ingredient. The samples in Table 1 were prepared by mixing cocamide MEA at 50–60°C, cooling to room temperature, and adding other ingredients to obtain the aqueous phase. The ingredients for the oil phase were then mixed to obtain the oil phase. The final sample was obtained by mixing the aqueous and oil phases. Example 2 This example demonstrates the effect of the type of oil on skin sensitization. Samples A, 1, and 2 were prepared as described in Example 1. A blind patch test was performed on the posterior skin of a group of at least 30 consumers. 0.02 mL of the samples were placed in the patch chamber. The test area was photographed, and then the patch containing the test sample was applied to the test area. After 24 hours, the camera again recorded the condition of the test area. Skin sensitization was assessed, and Table 2 shows the number of consumers who had different reactions. Table 2 Sample Number of Consumers LO L1 L2 L3 A 1 14 15 0 B 11 17 2 0 1 30 0 0 0 LO: negative; L1: suspicious reaction with only weak erythema; L2: weak positive reaction including erythema, infiltration, edema or papules; L3: strong positive reaction or the reaction exceeded the tested area. As shown in Table 2, the problem of skin sensitization caused by the multiphase composition comprising retinoid was unexpectedly resolved by including volatile silicone in the 5 multiphase composition.

Claims

1. A multiphase personal care composition characterized in that it comprises: (a) an aqueous phase, and (b) an oily phase comprising volatile silicone and retinoid, wherein the composition comprises fatty acid amide and the aqueous phase is visually distinct from, and in physical contact with, the oily phase.

2. The composition according to claim 1, further characterized in that the retinoid is selected from retinyl ester, retinol, retinal and retinoic acid, preferably the retinoid comprises retinyl ester, retinol or a mixture thereof, more preferably the retinoid comprises retinyl palmitate, retinyl propionate or a mixture thereof.

3. The composition according to claim 1 or 2, further characterized in that the retinoid is present in an amount of 0.00001 to 10%, preferably 0.001 to 5% and more preferably 0.1 to 0.6% by weight of the total amount of the composition.

4. The composition according to any of the preceding claims, further characterized in that the volatile silicone contains from 3 to 10 silicon atoms, preferably the volatile silicone is decamethylcyclopentasiloxane.

5. The composition according to claim 1 or 2, further characterized in that the amount of volatile silicone is in the range of 3 to 60%, preferably 28 to 42% by weight of the total amount of the composition.

6. The composition according to any of the preceding claims, further characterized in that the weight ratio of volatile silicone to retinoid is from 10:1 to 1000:1, preferably from 50:1 to 300:

1.

7. The composition according to any of the preceding claims, further characterized in that the fatty acid amide is in an amount of 0.01% to 4% by weight of the composition.

8. The composition according to any of the preceding claims, further characterized in that the composition comprises a non-ionic surfactant, preferably the composition comprises an alkyl glucoside.

9. The composition in accordance with any of the preceding claims, further characterized in that both the aqueous phase and the oily phase are transparent.

10. The composition according to any of the preceding claims, further characterized in that the weight ratio of the aqueous phase to the oily phase is in the range of 1:8 to 8:1, preferably 1:2 to 2:

1.

11. A kit of parts characterized in that it comprises a cosmetic container, a multi-phase personal care composition in accordance with any of claims 1 to 10 and instructions for use of the kit.

12. A method for preparing a personal care product characterized in that it comprises a step of shaking a cosmetic container containing the composition according to any of claims 1 to 10 by human hand.

13. A cosmetic method for providing skin lightening to the skin of an individual characterized in that it comprises the steps of (i) shaking a cosmetic container containing the composition according to any one of claims 1 to 10 with the human hand and (ii) applying the resulting product topically.