Stable multiple emulsion compositions

Abstract

Multiple emulsion compositions and methods for making the same are provided. The multiple emulsions can provide improved stability and personal care benefits.

Description

Technical Field

[0001] This invention relates to a multi-emulsion composition. This multi-emulsion can provide improved stability and beneficial effects for personal care. Background Technology

[0002] An emulsion is a dispersion of two or more liquids that are generally immiscible. Common examples of emulsions are oil-in-water (O / W) and water-in-oil (W / O) emulsions. Multiple emulsions are formed by using more than two fluids or by arranging more fluids in a more complex manner than typical two-fluid emulsions. For example, a multiple emulsion can be oil-in-water-in-oil (O / W / O) or water-in-oil-in-water (W / O / W). Multiple emulsions are of particular interest due to their current and potential applications in fields such as drug delivery, paints, inks and coatings, food and beverages, chemical separation, and personal care.

[0003] Multi-emulsions are a novel emulsion technology with a unique "three-phase and two-film" structure, potentially offering significant benefits to cosmetic formulations. They combine the advantages of both oil-in-water (O / W) and water-in-oil (W / O) emulsions, including long-lasting hydration and a refreshing skin feel, protection and stabilization of both hydrophilic and hydrophobic active ingredients, improved release of active ingredients onto the skin, and enhanced skin delivery. Furthermore, multi-emulsions exhibit transformative textures due to their unique water-in-oil-in-water structure, providing consumers with a unique skin feel unattainable with traditional single-emulsion formulations. However, a major challenge in creating stable multi-emulsions is their excessive surface free energy (leading to their thermodynamic instability).

[0004] This invention relates to a multiple emulsion comprising at least one water-in-oil emulsifier, at least one oil-in-water emulsifier, and at least one oil component. Specifically, the multiple emulsion is a water-in-oil-in-water emulsion. This invention also relates to a method for preparing a stable multiple emulsion, which can be applied in the cosmetics industry. Summary of the Invention

[0005] This invention relates to a multiple emulsion comprising at least one water-in-oil emulsifier, at least one oil-in-water emulsifier, and at least one oil component. The water-in-oil emulsifier is selected from the group consisting of: polyglycerol fatty acid esters comprising 2 to 6 glycerol units, esters or diesters of polyethylene glycol (PEG), linear or branched silicone emulsifiers, and mixtures thereof. The oil-in-water emulsifier is selected from the group consisting of: polyoxyethylene sorbitan fatty acid esters, alkyl glucosides, N-acyl amino acid emulsifiers, polyglycerol-10 fatty acid esters, monoesters or diesters of sulfosuccinates, and mixtures thereof. In particular, the multiple emulsion is a water-in-oil-in-water emulsion.

[0006] The present invention also relates to a method for preparing a stable water-in-oil-in-water emulsion, the method comprising i) preparing a water-in-oil emulsion, which includes the step of mixing an oil phase comprising at least one water-in-oil emulsifier and at least one oil component with a first aqueous phase, and ii) mixing the water-in-oil emulsion obtained in step (i) with a second aqueous phase comprising at least one oil-in-water emulsifier to obtain a stable water-in-oil-in-water emulsion, wherein the water-in-oil emulsifier is selected from the group consisting of: polyglycerol fatty acid esters comprising 2 to 6 glycerol units, esters or diesters of polyethylene glycol, linear or branched silicone emulsifiers; wherein the oil-in-water emulsifier is selected from the group consisting of: polyoxyethylene dehydrated sorbitol fatty acid esters, alkyl glucosides, N-acyl amino acid emulsifiers, polyglycerol-10 fatty acid esters and monoesters or diesters of sulfosuccinates. Detailed Implementation

[0007] Before explaining in detail at least one embodiment of the inventive concept disclosed and / or claimed herein, it should be understood that the inventive concept disclosed and / or claimed herein is not limited in its application to the details of the construction and arrangement of the components or steps or methods set forth in the following description. The inventive concept disclosed and / or claimed herein may have other embodiments or may be practiced or carried out in various ways. Furthermore, it should be understood that the wording and terminology used herein are for descriptive purposes and should not be considered limiting.

[0008] Unless otherwise defined herein, technical terms used in conjunction with the inventive concepts disclosed and / or claimed herein shall have the meanings commonly understood by one of ordinary skill in the art. Furthermore, unless the context requires otherwise, singular terms shall include plural terms, and plural terms shall include singular terms.

[0009] According to this disclosure, all compositions and / or methods disclosed herein can be made and performed without excessive experimentation. While compositions and methods of the inventive concepts disclosed and / or claimed herein have been described with respect to preferred embodiments, it will be apparent to those skilled in the art that variations may be applied to the compositions and / or methods described herein, as well as the steps or sequence of steps of the methods, without departing from the concept, spirit, and scope of the inventive concepts disclosed and / or claimed herein. All such similar substitutions and modifications that are apparent to those skilled in the art are considered to be within the spirit, scope, and concept of the inventive concepts disclosed and / or claimed herein.

[0010] Unless otherwise stated, the following terms shall be understood to have the following meanings when used in accordance with this disclosure.

[0011] Throughout the specification (including the claims), unless otherwise stated, the term "comprising one / a" shall be understood to be synonymous with the term "comprising at least one / a", and "between" shall be understood to include the limit.

[0012] The terms “a / an” and “the” are used to refer to the grammatical object of the article that is one or more (i.e., at least one).

[0013] The term “and / or” includes the meanings “and”, “or”, and all other possible combinations of elements associated with this term.

[0014] As used in this article, "HLB" refers to the hydrophilic-lipophilic balance or hydrophilic-lipophilic balance of a surfactant and is a measure of the hydrophilic or lipophilic properties of the surfactant.

[0015] This invention relates to a multiple emulsion comprising at least one water-in-oil emulsifier, at least one oil-in-water emulsifier, and at least one oil component. The water-in-oil emulsifier is selected from the group consisting of: polyglycerol fatty acid esters comprising 2 to 6 glycerol units, esters or diesters of polyethylene glycol (PEG), linear or branched silicone emulsifiers, and mixtures thereof. The oil-in-water emulsifier is selected from the group consisting of: polyoxyethylene sorbitan fatty acid esters, alkyl glucosides, N-acyl amino acid emulsifiers, polyglycerol-10 fatty acid esters, monoesters or diesters of sulfosuccinates, and mixtures thereof. In particular, the multiple emulsion is a water-in-oil-in-water emulsion.

[0016] Water-in-oil emulsifier

[0017] Water-in-oil emulsifiers have a hydrophilic-lipophilic balance (HLB) value of less than 10, preferably 6 or less. According to any embodiment of the invention, suitable water-in-oil emulsifiers include polyglycerol fatty acid esters comprising 2 to 6 glycerol units, polyethylene glycol monoesters or diesters, and straight-chain or branched silicone emulsifiers.

[0018] Straight-chain and / or branched-chain silicone emulsifiers

[0019] bis-butyl polydimethylsiloxane polyglycerol-3; bis-PEG / PPG-14 / 14 polydimethylsiloxane; bis-butyl polydimethylsiloxane polyglycerol-3; bis-isobutyl PEG / PPG-10 / 7 polydimethylsiloxane copolymer; bis-PEG / PPG-18 / 6 polydimethylsiloxane; bis-PEG / PPG-20 / 20 polydimethylsiloxane; bis-PEG / PPG-16 / 16 PEG / PPG-16 / 16 polydimethylsiloxane; bis(PPG-7 undecenol polyether-21-polydimethylsiloxane); cetyl polydimethylsiloxane PEG-7 acetate; cetyl PEG-8 polydimethylsiloxane; cetyl PEG / PPG-15 / 16 butyl ether polydimethylsiloxane; cetyl PEG / PPG-15 / 15 butyl ether polydimethylsiloxane; cetyl PEG / PPG-7 / 3 polydimethylsiloxane; cetyl PEG / PPG-10 / 1 polydimethylsiloxane; polydimethylsiloxane PEG-15 acetate; polydimethylsiloxane PEG- 7. Cocoate; Polydimethylsiloxane PEG-7 phosphate; Polydimethylsiloxane PEG-10 phosphate; Polydimethylsiloxane PEG / PPG-7 / 4 phosphate; Polydimethylsiloxane PEG / PPG-12 / 4 phosphate; Polydimethylsiloxane PEG-7 undecenoate; Lauryl polydimethylsiloxane PEG-10 phosphate; Isopolyglycerol-3 polydimethylsiloxane; Isopolyglycerol-3 polydimethylsiloxane alcohol; Isostearyl carboxydecyl PEG-8 polydimethylsiloxane; Lauryl polymethylsiloxane PEG-10 phosphate; Lauryl PEG-8 polydimethylsiloxane; Laureth PEG-10 methyl ether polydimethylsiloxane; lauryl PEG / PPG-18 / 18 polymethylsiloxane; PEG-6 methyl ether polydimethylsiloxane; PEG-7 methyl ether polydimethylsiloxane; PEG-9 methyl ether polydimethylsiloxane; PEG-10 methyl ether polydimethylsiloxane; PEG-11 methyl ether polydimethylsiloxane; PEG-11 methyl ether polydimethylsiloxane; PEG-32 methyl ether polydimethylsiloxane; PEG-PEG / PPG-28 / 21 acetate polydimethylsiloxane; PEG / PPG-22 / 22 butyl ether polydimethylsiloxane; PEG / PPG-23 / 23 Butyl Ether Polydimethylsiloxane; PEG / PPG-24 / 18 Butyl Ether Polydimethylsiloxane; PEG / PPG-3 / 10 Polydimethylsiloxane; PEG / PPG-4 / 12 Polydimethylsiloxane; PEG / PPG-6 / 11 Polydimethylsiloxane; PEG / PPG-8 / 14 Polydimethylsiloxane; PEG / PPG-12 / 16 Polydimethylsiloxane; PEG / PPG-12 / 18 Polydimethylsiloxane; PEG / PPG-14 / 4 Polydimethylsiloxane; PEG / PPG-15 / 5 Polydimethylsiloxane;PEG / PPG-15 / 15 polydimethylsiloxane; PEG / PPG-16 / 2 polydimethylsiloxane; PEG / PPG-16 / 8 polydimethylsiloxane; PEG / PPG-17 / 18 polydimethylsiloxane; PEG / PPG-18 / 12 polydimethylsiloxane; PEG / PPG-19 / 19 polydimethylsiloxane; PEG / PPG-20 / 6 polydimethylsiloxane; PEG / PPG-20 / 15 polydimethylsiloxane; PEG / PPG-20 / 20 polydimethylsiloxane; PEG / PPG-22 / 23 polydimethylsiloxane; PEG / PPG-22 / 24 polydimethylsiloxane; PEG / PPG-25 / 25 polydimethylsiloxane; PEG / PPG-27 / 27 polydimethylsiloxane; PEG / PPG-30 / 10 polydimethylsiloxane; PEG / PPG-10 / 3 oleyl ether polydimethylsiloxane; PEG-8 trisiloxane; polyglycerol-3 polydimethylsiloxyethyl polydimethylsiloxane; PPG-12 butyl ether polydimethylsiloxane; silicone quaternary ammonium salt-17; TEA-polydimethylsiloxane PEG-7 phosphate ester; and mixtures thereof. Preferably, the most suitable silicone emulsifier for use in this invention is cetyl PEG / PPG-10 / 1 polydimethylsiloxane.

[0020] Polyglycerol fatty acid esters containing 2 to 6 glycerol units

[0021] One suitable water-in-oil emulsifier for use in this invention comprises a polyglycerol fatty acid ester containing 2 to 6 glycerol units. Exemplary water-in-oil emulsifiers include polyglycerol laurate having 2 to 6 glycerol units, polyglycerol mono / dioleate / trioleate having 2 to 6 glycerol units, polyglycerol stearate having 2 to 6 glycerol units, polyglycerol isostearate having 2 to 6 glycerol units, polyglycerol distearate / diisostearate having 2 to 6 glycerol units, polyglycerol polyhydroxystearate having 2 to 6 glycerol units, polyglycerol dihydroxystearate having 2 to 6 glycerol units, and polyglycerol polyricinoleate having 2 to 6 glycerol units. Particularly preferred water-in-oil emulsifiers include polyglycerol-2-dihydroxystearate, polyglycerol-2-diisostearate, polyglycerol-2-polyhydroxystearate, and polyglycerol-6-polyricinoleate.

[0022] Polyglycerol polyricinoleate

[0023] The term "polyglycerol polyricinoleate" in the sense of this invention refers to an ester produced by the esterification of one or more polyglycerols with at least one polyricinoleic acid.

[0024] The polyglycerol polyricinoleate surfactant suitable for use in this invention can be a total ester or a partial ester. Within the meaning of this invention, the term "partial ester" is intended to refer to a compound in which all -OH groups of the polyglycerol units have not been polyricinoleate-substituted; in other words, a polyglycerol polyricinoleate containing at least one free -OH group on the polyglycerolized chain. Suitable polyglycerol polyricinoleates for use in this invention may include polyglycerol-3 polyricinoleate, polyglycerol-5 polyricinoleate, polyglycerol-6 polyricinoleate, and more particularly, selected from polyglycerol-3 polyricinoleate and polyglycerol-6 polyricinoleate and mixtures thereof, and even more preferably polyglycerol-6 polyricinoleate.

[0025] (Mono)ester or diester of polyethylene glycol

[0026] Preferred suitable water-in-oil emulsifiers are esters or diesters of polyethylene glycol (PEG), such as PEG-30 dihydroxystearate, PEG-4 dilaurate, PEG-8 dioleate, PEG-40 sorbitan peroleate, PEG-7 glyceryl cocoate, PEG-25 hydrogenated castor oil, PEG-7 olive oil, PEG-8 oleate, and PEG-8 laurate. Preferably, PEG-30 dihydroxystearate is one of the most suitable water-in-oil emulsifiers for use in this invention.

[0027] In some preferred embodiments of the present invention, the water-in-oil emulsifier is a monoester or diester of polyethylene glycol, a polyglycerol fatty acid ester containing 2 to 6 glycerol units, or a combination of a monoester or diester of polyethylene glycol and a polyglycerol fatty acid containing 2 to 6 glycerol units.

[0028] Preferably, the water-in-oil emulsifier is PEG-30 dimerhydroxystearate, polyglycerol polyhydroxystearate having 2 to 6 glycerol units, polyglycerol didihydroxystearate having 2 to 6 glycerol units, polyglycerol polyricinoleate having 2 to 6 glycerol units, polyglycerol distearate / diisostearate having 2 to 6 glycerol units, or a mixture thereof. More preferably, the water-in-oil emulsifier is PEG-30 dimerhydroxystearate, polyglycerol-2 dimerhydroxystearate, polyglycerol polyricinoleate (e.g., polyglycerol-6-polyricinoleate), or a mixture thereof. Even more preferably, the water-in-oil emulsifier is PEG-30 dimerhydroxystearate or a combination of PEG-30 dimerhydroxystearate and polyglycerol-2 dimerhydroxystearate.

[0029] Oil-in-water emulsifier

[0030] The oil-in-water emulsifier has a hydrophilic-lipophilic balance (HLB) value greater than or equal to 10. Preferably, the oil-in-water emulsifier suitable for use in this invention has an HLB value greater than 10.

[0031] The oil-in-water emulsifier suitable for this invention is selected from the group consisting of: polyoxyethylene dehydrated sorbitol fatty acid esters, alkyl glucosides, N-acyl amino acid emulsifiers, polyglycerol-10 fatty acid esters, and monoesters or diesters of sulfosuccinates.

[0032] Polyoxyethylene dehydrated sorbitol fatty acid ester

[0033] Suitable polyoxyethylene dehydrated sorbitol fatty acid esters include polysorbate 20, polysorbate 80, polysorbate 60 and polysorbate 85.

[0034] Alkyl glucoside

[0035] Alkyl glucosides are those containing an alkyl group comprising 6 to 30 carbon atoms, preferably 8 to 18 carbon atoms, and containing a hydrophilic (glucosidic) group, preferably comprising 1.2 to 3 sugar units. Examples suitable for use in this invention include octanoyl / decanoyl glucoside, lauryl glucoside, cocoyl glucoside, cetearyl glucoside, optionally as a mixture with cetearyl alcohol. In preferred embodiments, cetearyl glucoside is most preferably used in this invention.

[0036] N-acyl amino acid emulsifiers

[0037] The N-acyl amino acid emulsifier used in this invention is an N-long-chain acyl amino acid or a salt thereof. The long-chain acyl group constitutes an N-long-chain acyl acidic amino acid, having a straight-chain or branched acyl group with 6 to 20 carbon atoms, and the hydrocarbon chain can be saturated or unsaturated. When the acyl group is unsaturated, it may contain two or more unsaturated bonds, and the unsaturated bonds can be conjugated or non-conjugated. Examples of acyl groups include, for example, acyl groups from which acyl acids, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, benzyl acid, linoleic acid, linoleic acid, oleic acid, isostearic acid, 2-ethylhexanoic acid, coconut oil fatty acids, tallow fatty acids, hydrogenated tallow fatty acids, etc., can be derived. Among these, acyl groups having 8 to 18 carbon atoms or 10 to 16 carbon atoms are more preferred, and examples include octanoyl, decanoyl, lauroyl, myristyl, palmitoyl, stearoyl, coconut oil fatty acid acyl (cocoyl), hydrogenated tallow fatty acid acyl, palm kernel oil fatty acid acyl, etc. In this specification, "mixed acyl groups" refers to a mixture of acyl groups with different chain lengths. Examples of acidic amino acids constituting long-chain acyl acidic amino acids include taurine, sarcosine, glycine, serine, alanine, lysine, arginine, proline, threonine, valine, isoleucine, histidine, phenylalanine, preferably glutamic acid, sarcosine, and taurine, among which glutamic acid and taurine are preferred in this invention. The type of salt of N-long-chain acyl acidic amino acids is not particularly limited. Examples of salts include sodium salts, magnesium salts, potassium salts, ammonium salts, diethanolamine salts, triethanolamine salts, arginine salts, lysine salts, etc.

[0038] Examples of N-long-chain acyl acidic amino acids and their salts include N-long-chain acyl glutamic acid and its salts, such as N-cocoyl glutamic acid and its salts, N-lauroyl glutamic acid and its salts, N-stearoyl glutamic acid and its salts, N-myristoyl glutamic acid and its salts, N-palmitoyl glutamic acid and its salts, and N-oleoyl glutamic acid and its salts; N-long-chain acyl taurine and its salts, such as N-cocoyl taurine and its salts, N-stearoyl taurine and its salts, N-myristoyl taurine and its salts, N-palmitoyl taurine and its salts, and N-oleoyl taurine and its salts, as well as N-lauroyl taurine or its salts; N-long-chain acyl sarcosine and its salts, such as N-cocoyl sarcosine and its salts, N-stearoyl sarcosine and its salts, and N-lauroyl sarcosine or its salts, etc. Among them, particularly preferred examples include N-cocoylglutamic acid and its salts, and N-lauroylglutamic acid and its salts. Among them, particularly preferred examples include N-stearoylglutamic acid and its salts, and N-lauroylglutamic acid and its salts. Two or more N-long-chain acyl acidic amino acids or their salts may be used in combination. The most preferred examples are a monosodium salt of N-stearoylglutamic acid (sodium stearoylglutamate) and a monosodium salt of N-cocoylglutamic acid (sodium cocoylglutamate).

[0039] Polyglycerol-10 fatty acid esters

[0040] Suitable oil-in-water emulsifiers may also include polyglycerol-10 fatty acid esters, such as polyglycerol-10 oleate, polyglycerol-10 dioleate, polyglycerol-10 isostearate, polyglycerol-10 trilaurate, polyglycerol-10 myristate, polyglycerol-10 dimyristate, polyglycerol-10 stearate, and polyglycerol-10 distearate. Preferred polyglycerol fatty acid esters are polyglycerol-10 stearate and polyglycerol-10 oleate.

[0041] Monoesters or diesters of sulfosuccinate

[0042] Suitable oil-in-water emulsifiers may include monoesters or diesters of sulfosuccinates. Exemplary sulfosuccinates include ammonium lauryl sulfosuccinate, diammonium lauryl sulfosuccinate, sodium dioctyl sulfosuccinate, disodium cetearyl sulfosuccinate, disodium cocoamide sulfosuccinate, disodium cocoyl glucoside sulfosuccinate, disodium polydimethylsiloxane copolyol sulfosuccinate, disodium hydrogenated cottonseed glyceryl ester sulfosuccinate, disodium isostearyl sulfosuccinate, disodium lauryl ether sulfosuccinate, etc.

[0043] In some preferred embodiments of the present invention, the oil-in-water emulsifier is an N-acyl amino acid emulsifier, a polyglycerol-10 fatty acid ester, a monoester or diester of a sulfosuccinate, or a mixture thereof. Preferably, the oil-in-water emulsifier is selected from the group consisting of: sodium stearoyl glutamate, sodium cocoyl glutamate, polyglycerol-10 stearate, polyglycerol-10 oleate, disodium cetearyl sulfosuccinate, and mixtures thereof. More preferably, the oil-in-water emulsifier is selected from the group consisting of: sodium stearoyl glutamate, disodium cetearyl sulfosuccinate, and mixtures thereof.

[0044] According to any embodiment of the present invention, the present invention relates to a multiple emulsion comprising at least one water-in-oil emulsifier, at least one oil-in-water emulsifier, and at least one oil component, wherein the water-in-oil emulsifier is selected from the group consisting of: polyglycerol fatty acid esters comprising 2 to 6 glycerol units, monoesters or diesters of polyethylene glycol (PEG), linear or branched silicone emulsifiers, and mixtures thereof; wherein the oil-in-water emulsifier is selected from the group consisting of: polyoxyethylene sorbitan fatty acid esters, alkyl glucosides, N-acyl amino acid emulsifiers, polyglycerol-10 fatty acid esters, monoesters or diesters of sulfosuccinates, and mixtures thereof. In particular, the multiple emulsion is a water-in-oil-in-water emulsion. Preferably, in some embodiments of the invention, the multiple emulsion comprises an oil-in-water emulsifier selected from the group consisting of: monoesters or diesters of polyethylene glycol, polyglycerol fatty acid esters comprising 2 to 6 glycerol units, and combinations thereof; and an oil-in-water emulsifier selected from the group consisting of: N-acyl amino acid emulsifiers, polyglycerol-10 fatty acid esters, monoesters or diesters of sulfosuccinates, and mixtures thereof. Preferably, the multiple emulsion comprises an oil-in-water emulsifier selected from the group consisting of: PEG-30 dimerhydroxystearate, polyglycerol polyhydroxystearate having 2 to 6 glycerol units, polyglycerol dihydroxystearate having 2 to 6 glycerol units, polyglycerol distearate / diisostearate having 2 to 6 glycerol units, polyglycerol polyricinoleate having 2 to 6 glycerol units, and mixtures thereof. More preferably, the multiple emulsion comprises a water-in-oil emulsifier selected from the group consisting of PEG-30 dimerhydroxystearate, polyglycerol-2 dimerhydroxystearate, polyglycerol-6 polyricinoleate, and combinations thereof. In particular, the multiple emulsion of the present invention further comprises an oil-in-water emulsifier selected from the group consisting of sodium stearoyl glutamate, sodium cocoyl glutamate, polyglycerol-10 stearate, polyglycerol-10 oleate, disodium cetearyl sulfosuccinate, and mixtures thereof. Even more preferably, in some embodiments of the present invention, the multiple emulsion comprises a water-in-oil emulsifier selected from the group consisting of PEG-30 dimerhydroxystearate and combinations of PEG-30 dimerhydroxystearate and polyglycerol-2 dimerhydroxystearate, and an oil-in-water emulsifier selected from the group consisting of sodium stearoyl glutamate, disodium cetearyl sulfosuccinate, and mixtures thereof.

[0045] In some preferred embodiments, the water-in-oil emulsifier is present in an amount of 0.2% to 10%, preferably 0.3% to 8%, more preferably 0.3% to 6% based on the total weight of the multiple emulsions; preferably, the oil component is present in an amount of 0.5% to 20%, preferably 0.5% to 15% based on the total weight of the multiple emulsions; preferably, the oil-in-water emulsifier is present in an amount of 0.2% to 6.0%, preferably 0.4% to 4.0%, more preferably 0.4% to 3.0% based on the total weight of the multiple emulsions.

[0046] Oil component

[0047] Any conventionally used oil component is suitable for this invention. The oil component / emollient may be selected from the group consisting of: oils of animal or plant origin, synthetic glycerides, fatty esters, fatty alcohols, and aliphatic hydrocarbons. These materials may be volatile or non-volatile. Suitable oils may be selected from aliphatic hydrocarbons, vegetable oils, fatty alcohols, fatty alcohols other than animal or vegetable oils and / or esters of fatty acids and synthetic glycerides, or mixtures thereof. Particularly suitable oils may be selected from the group consisting of vegetable oils, esters of fatty alcohols, and mixtures thereof.

[0048] Suitable plant oils for use in the cosmetic compositions of the present invention may, non-exclusively, include flaxseed oil, camellia oil, sunflower oil, almond oil, hazelnut oil, vegetable squalane oil, tea oil, grapeseed oil, peanut oil, coconut oil, palm kernel oil, soybean oil, macadamia nut oil, avocado oil, safflower oil, sweet almond oil, almond oil, corn oil, jojoba oil, olive oil, sesame oil, palm oil, eucalyptus oil, rosemary oil, lavender oil, pine oil, thyme oil, peppermint oil, cardamom oil, neroli oil, rice bran oil, rapeseed oil, castor oil, and mixtures thereof.

[0049] Suitable animal oils used in the cosmetic compositions of the present invention may non-exclusively include squalene, perhydrosqualene, squalane, and mixtures thereof.

[0050] Suitable fatty alcohols can be C 10 -C 26 Alcohols, preferably monohydric alcohols.

[0051] Suitable fatty esters or fatty alcohols in the cosmetic compositions of the present invention may include fatty acid polyglycerides, such as diglycerides, triglycerides, preferably triglycerides of saturated and / or unsaturated, branched and / or unbranched alkane carboxylic acids with a chain length of 6 to 24, particularly 6 to 18 carbon atoms, more preferably triisooctanoic acid glycerides and caprylic / capric triglycerides, dialkyl carbonates such as dioctyl carbonate and dicaprylyl carbonate, diisopropyl sebacate, ethyl laurate, butyl laurate, hexyl laurate, isohexyl laurate, isopropyl laurate, methyl myristate, ethyl myristate, butyl myristate, isobutyl myristate, isopropyl myristate, 2-octyl dodecyl myristate, 2-ethylhexyl cocoate (or octyl cocoate), ethyl palmitate, palmitic acid ... Isopropyl palmitate, isobutyl palmitate, 2-ethylhexyl palmitate (or octyl palmitate), butyl stearate, isopropyl stearate, isocetyl stearate, isostearate, isopropyl stearate, 2-ethylhexyl stearate (or octyl stearate), decyl oleate, isononyl isononanoate, tridecyl neopentanoate, isocetyl neopentanoate, isostearate, octyl dodecyl neopentanoate, and isoarachidyl neopentanoate, and mixtures thereof.

[0052] In the embodiments, suitable oils may be commercially available, such as those from BASF as MYRITOL® GTEH, MYRITOL® GTEH-SD, MYRITOL® 318 RC, CETIOL® CC, CEGESOFT® PS6, CEGESOFT® C24RC, CETIOL® ININ, CETIOL® SN-1 SD, and CETIOL® ULTIMATE. All commercially available (from BASF) and cosmetically acceptable oils or mixtures thereof are suitable for use in the compositions of the present invention.

[0053] In this invention, some waxes can also be used in the oil phase. Suitable waxes may include waxes of natural origin, such as beeswax, lanolin wax, Chinese insect wax, rice bran wax, carnauba wax, candelilla wax, crown carnauba wax, Spanish grass wax, berry wax, shellac wax, Japanese wax and lacquer wax, lignite wax, orange wax, lemon wax, ceresin wax, and hydrogenated oils such as hydrogenated jojoba oil; waxes of synthetic origin, such as microcrystalline wax, paraffin wax, polyethylene wax (derived from the polymerization of ethylene); waxes obtained by Fischer-Tropsch synthesis (Fischer-Tropsch waxes) and wax copolymers, as well as their esters; waxes containing straight-chain or branched C8-C... 32 Fatty acid chain, preferred C 16 To C 18Fatty acids or esters obtained from chain animal or vegetable oils; silicone waxes; fluorinated waxes; or mixtures thereof. Suitable waxes may also be derived from C6-C. 30 Solid linear esters of fatty acids, examples of which include stearyl stearate, tetradecyl stearate (INCI name: myristyl myristate), cetyl myristate, stearyl myristate, myristyl palmitate, stearyl palmitate, myristyl stearate, cetyl stearate, stearyl stearate and cetyl palmitate, and mixtures thereof.

[0054] The multiple emulsion of the present invention comprises at least one water-in-oil emulsifier, at least one oil-in-water emulsifier, and at least one oil component, wherein the water-in-oil emulsifier is selected from the group consisting of: polyglycerol fatty acid esters comprising 2 to 6 glycerol units, monoesters or diesters of polyethylene glycol (PEG), and linear or branched silicone emulsifiers; wherein the oil-in-water emulsifier is selected from the group consisting of: polyoxyethylene dehydrated sorbitol fatty acid esters, alkyl glucosides, N-acyl amino acid emulsifiers, polyglycerol-10 fatty acid esters, monoesters or diesters of sulfosuccinates, and mixtures thereof. In particular, the multiple emulsion is a water-in-oil-in-water emulsion. Preferably, in some embodiments of the invention, the multiple emulsion comprises: an oil-in-water emulsifier selected from the group consisting of: a monoester or diester of polyethylene glycol, a polyglycerol fatty acid ester comprising 2 to 6 glycerol units, and combinations thereof; and an oil-in-water emulsifier selected from the group consisting of: an N-acyl amino acid emulsifier, a polyglycerol-10 fatty acid ester, a monoester or diester of sulfosuccinate, and mixtures thereof. Preferably, the oil-in-water emulsifier is present in an amount of 0.2% to 10%, preferably 0.3% to 8%, more preferably 0.3% to 6% based on the total weight of the multiple emulsion; preferably, the oil component is present in an amount of 0.5% to 20%, preferably 0.5% to 15% based on the total weight of the multiple emulsion; preferably, the oil-in-water emulsifier is present in an amount of 0.2% to 6.0%, preferably 0.4% to 4.0%, more preferably 0.4% to 3.0% based on the total weight of the multiple emulsion.

[0055] The multi-emulsion of this invention can be used in any suitable personal care or cosmetic formulation. In embodiments of the invention claimed herein, in preferred embodiments, the personal care and / or cosmetic compositions may further comprise additional nonionic, anionic emulsifiers.

[0056] In embodiments of the present invention, the personal care and / or cosmetic composition further comprises at least one adjuvant selected from the group consisting of: anti-wrinkle active agents, anti-acne active agents, emulsifiers, antioxidants, emollients, self-tanning active agents, skin whitening agents, sunscreens, UV absorbers, thickeners, humectants, abrasives, absorbents, fragrances, buffers, sunscreens, colorants, preservatives, fillers, pH adjusters, and solvents.

[0057] In some embodiments of the present invention, the active agent is selected from the group consisting of: anti-wrinkle agents such as retinol, hyaluronic acid, ceramide, niacinamide, vitamin E, and alpha-hydroxy acids; and anti-acne agents such as clindamycin, bemaconazole, benzoyl peroxide, and isotretinoin. In some embodiments of the present invention, the skin whitening agent is selected from the group consisting of: retinoic acid, hydroquinone, resorcinol, arbutin, kojic acid, azelaic acid, vitamin C, glutathione, and alpha-hydroxy acids.

[0058] In some embodiments of the invention, the personal care and / or cosmetic composition may further comprise at least one thickener. The thickener may be selected from the group consisting of polymeric thickeners (including nonionic and anionic thickeners, or mixtures thereof). Suitable nonionic thickeners include polyacrylamide polymers, crosslinked poly(N-vinylpyrrolidone), polysaccharides, natural or synthetic gums or polysaccharides, polyvinylpyrrolidone, and polyvinyl alcohol. Suitable anionic thickeners include polyacrylates, acrylate / ethyl acrylate copolymers, carboxyvinyl polymers, and crosslinked copolymers of alkyl vinyl ethers and maleic anhydride.

[0059] In some embodiments of the present invention, the thickener is selected from the group consisting of: polysaccharides, including cellulose, carboxymethyl hydroxyethyl cellulose, cellulose acetate propionate, hydroxyethyl cellulose, hydroxyethyl ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, methyl hydroxyethyl cellulose, microcrystalline cellulose, sodium cellulose sulfate, and mixtures thereof; natural gums, such as gum arabic, agar, alginic acid, ammonium alginate, amylopectin, calcium alginate, carrageenan calcium, carnitine, carrageenan, dextrin, gelatin, gellan gum, guar gum, and guar hydroxyl grouper. The following are included: propyltrimethylammonium chloride, lithium montmorillonite, hyaluronic acid, hydrated silica, hydroxypropyl chitosan, hydroxypropyl guar gum, ark sylvestris gum, seaweed, locust bean gum, natto gum, potassium alginate, potassium carrageenan, propylene glycol alginate, sclerotium gum, sodium carboxymethyl dextran, sodium carrageenan, tragacanth gum, xanthan gum, and mixtures thereof. Preferably, the thickener is selected from the group consisting of xanthan gum, succinosaccharide, gellan gum, pectin, alginate, starch, guar gum, acrylates, acrylate copolymers, carbomer, and associative thickeners. According to any embodiment of the invention, the thickener is present in an amount ranging from 0.1% to 5% by weight based on the total weight of the personal care and / or cosmetic composition.

[0060] In some embodiments of the invention, the wetting agent is selected from the group consisting of: sodium 2-pyrrolidone-5-carboxylate (NaPCA), guanidine, glycolic acid and glycolates (e.g., ammonium and quaternary alkylammonium), lactic acid and lactates (e.g., ammonium or quaternary alkylammonium), aloe vera in any of its various forms (e.g., aloe vera gel), hyaluronic acid and its derivatives (e.g., salt derivatives such as sodium hyaluronate), lactamide monoethanolamine, acetamide monoethanolamine, urea, panthenol and its derivatives, and mixtures thereof.

[0061] In some embodiments of the invention, the buffer is selected from the group consisting of: lactic acid, lactate, gluconic acid, gluconic acid-δ-lactone, sodium gluconate and potassium gluconate, trisodium citrate, tripotassium citrate, sodium lactate, potassium lactate, triethanolamine and sodium hydroxide.

[0062] In some embodiments of the present invention, the solvent is selected from the group consisting of: polyols, including glycerol, diglycerol, triglycerol, polyglycerol, polypropylene glycol, polyethylene glycol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, hexanediol, 1,3-butanediol, 1,4-butanediol, ethylene glycol monoalkyl ethers, diethylene glycol monoalkyl ethers, glucose, maltose, sucrose, lactose, xylose, xylitol, sorbitol, mannitol, maltitol, malbitol, panthenol, pentaerythritol, and hyaluronic acid and their salts; water; ethanol and isopropanol. In some embodiments of the present invention, the solvent is selected from the group consisting of glycerol, water, and ethanol.

[0063] According to any embodiment of the invention, the personal care and / or cosmetic composition further comprises a carrier or a mixture of such carriers suitable for application to the skin and / or hair. Suitable carriers for use in topical compositions include water, C1-C6 alcohols, lower alkyl acetates, and mixtures thereof. In some embodiments, the carrier may also contain a variety of additional materials such as acetone, hydrocarbons (e.g., isobutane, hexane, decene, halogenated hydrocarbons), and volatile silicones (e.g., cyclomethylsiloxane). In one embodiment, water is present in the topical composition in an amount ranging from 5% to 80% by weight based on the total weight of the composition.

[0064] The present invention also relates to a method for preparing a stable water-in-oil-in-water emulsion, the method comprising i) preparing a water-in-oil emulsion, which includes the step of mixing an oil phase comprising at least one water-in-oil emulsifier and at least one oil component with a first aqueous phase, and ii) mixing the water-in-oil emulsion obtained in step (i) with a second aqueous phase comprising at least one oil-in-water emulsifier, wherein the water-in-oil emulsifier is selected from the group consisting of: polyglycerol fatty acid esters comprising 2 to 6 glycerol units, (mono)esters or diesters of polyethylene glycol, linear or branched silicone emulsifiers; wherein the oil-in-water emulsifier is selected from the group consisting of: polyoxyethylene dehydrated sorbitol fatty acid esters, alkyl glucosides, N-acyl amino acid emulsifiers, polyglycerol-10 fatty acid esters and monoesters or diesters of sulfosuccinates. In some preferred embodiments, step (ii) of mixing the water-in-oil emulsion obtained in step (i) with the second aqueous phase further includes a homogenization step, wherein the homogenization rate is between 3,000 and 6,000 rpm.

[0065] In the above method, preferably, the water-in-oil emulsifier is a monoester or diester of polyethylene glycol, a polyglycerol fatty acid ester having 2 to 6 glycerol units, or a mixture thereof. More preferably, the water-in-oil emulsifier is PEG-30 dimerhydroxystearate, polyglycerol-2 dimerhydroxystearate, polyglycerol-6 polyricinoleate, or a mixture thereof. Even more preferably, the water-in-oil emulsifier is PEG-30 dimerhydroxystearate, or a combination of PEG-30 dimerhydroxystearate and polyglycerol-2 dimerhydroxystearate. More preferably, the oil-in-water emulsifier is selected from the group consisting of: N-acyl amino acid emulsifiers, polyglycerol-10 fatty acid esters, monoesters or diesters of sulfosuccinate, or mixtures thereof. More preferably, the oil-in-water emulsifier is selected from the group consisting of: sodium stearoyl glutamate, sodium cocoyl glutamate, polyglycerol-10 stearate, polyglycerol-10 oleate, disodium cetearyl sulfosuccinate, or mixtures thereof. More preferably, the oil-in-water emulsifier is sodium stearoyl glutamate, sodium cocoyl glutamate, disodium cetearyl sulfosuccinate, or a mixture thereof. Example

[0066] The invention will now be further illustrated with reference to the following examples; however, these examples are for illustrative purposes and are not intended to limit the scope of the invention.

[0067] raw materials

[0068] The industrial products used in the examples are listed in the table below and are used as received.

[0069] Table 1. Industrial products used in the examples.

[0070]

[0071] Propylene glycol, magnesium sulfate heptahydrate, glycerol, mineral oil (10#) and triethanolamine were obtained as chemical reagents and used as received.

[0072] Preparation method

[0073] Manufacturing process

[0074] Unless otherwise stated, preparations containing water-in-oil-in-water (W / O / W) structures shall be manufactured in the same manner as described below.

[0075] 1. Preparation of Phase O: Mix each composition in Phase O. Heat the mixture to approximately 50°C–60°C. Stir Phase O until it is homogeneous.

[0076] 2. Preparation of Phase W1: Mix the components in Phase W1. Heat the mixture to approximately 50°C-60°C. Stir Phase W1 until it is homogeneous.

[0077] 3. Slowly add phase W1 to phase O while stirring. Then homogenize (5000 rpm, 3 minutes for a 200 g sample). This is the W1 / O emulsion. Set it aside for later use.

[0078] 4. Preparation of Phase W2: Mix the components in Phase W2. Heat the mixture to approximately 50°C-60°C. Stir Phase W2 until it is homogeneous. Add the polymer last to avoid prolonged heating.

[0079] 5. Heat the W1 / O emulsion prepared in step 3 to approximately 50°C-60°C. Avoid prolonged heating of the W1 / O emulsion.

[0080] 6. Add the W1 / O emulsion to phase W2 with stirring. Then homogenize (1500 rpm, 3 minutes for 200 g sample).

[0081] 7. Cool the sample to room temperature.

[0082] Example 1

[0083] This example demonstrates the importance of selecting water-in-oil emulsifiers in formulations.

[0084] The composition of preparations 1 to 4 is listed in Table 2.

[0085] The weight ratios of all components in the W1 / O emulsion in the following formulations (Formulations 1 to 33) are calculated based on the active substances in the W1 / O emulsion. The weight ratios of the components in the W1 / O emulsion and the external aqueous (W2) phase in the following formulations (Formulations 1 to 33) are calculated based on the active substances in the formulation.

[0086] Table 2: Composition of preparations 1 to 4.

[0087]

[0088] The weight ratios of all components present in formulations 1 to 4 in the multiple emulsions are shown in Table 2-1 below. The weight ratios of the components used in the oil phase (O) and the internal aqueous phase (W1) are adjusted to the amounts present in the multiple emulsion (W1 / O / W2).

[0089] Table 2-1

[0090]

[0091] The microstructure of each formulation was characterized by optical microscopy, and the results are shown in Table 11. Furthermore, the stability of the formulations is also recorded in Table 13.

[0092] Formulations 1-4 all exhibited multiple emulsion structures under an optical microscope, indicating that all four w / o emulsifiers—PEG-30 dihydroxystearate, polyglycerol-2 dihydroxystearate, cetyl PEG / PPG-10 / 1 polydimethylsiloxane, and polyglycerol-6 polyricinoleate—can be used to form multiple emulsions.

[0093] To optimize the dosage of the W / O emulsifier in the formulation, the formulation in Example 2 was prepared. Here, PEG-30 dimerized hydroxystearate was selected as the W / O emulsifier.

[0094] Example 2

[0095] This example demonstrates the appropriate dosage range for water-in-oil emulsifiers in formulations.

[0096] The composition of preparations 5 and 6 is listed in Table 3.

[0097] Table 3: Composition of preparations 5 and 6.

[0098]

[0099] The microstructure of each formulation was characterized by optical microscopy, and the results are shown in Table 11. Furthermore, the stability of the formulations is also recorded in Table 13.

[0100] The results showed that multiple emulsion structures were observed for both formulations 1 and 5.

[0101] To further evaluate the formation and stability of multiple emulsion structures, different types of emollients were evaluated, and the formulations shown in Table 4 were prepared.

[0102] Example 3

[0103] This example further demonstrates the emollient compatibility of this W / O / W emulsion formulation structure.

[0104] The composition of preparations 7 to 13 is listed in Table 4.

[0105] Table 4: Composition of Preparations 7 to 13

[0106]

[0107] The microstructure of each formulation was characterized by optical microscopy, and the results are shown in Table 11. Furthermore, the stability of the formulations is also recorded in Table 13.

[0108] Microscopic imaging results show that all formulations in Table 4 exhibit a multiple emulsion structure, indicating that the multiple emulsion structure has good compatibility with all oil components / emollients with various polarities and chemical structures.

[0109] Example 4

[0110] This example demonstrates the importance of selecting oil-in-water emulsifiers in multi-emulsion formulations.

[0111] The composition of preparations 14 to 20 is listed in Table 5.

[0112] Table 5: Composition of preparations 14 to 20.

[0113]

[0114] The microstructure of each formulation was characterized by optical microscopy, and the results are shown in Table 11. Furthermore, the stability of the formulations is also recorded in Table 13.

[0115] Formulations 1, 14, 15, and 18 all exhibited multiple emulsion structures under an optical microscope, indicating that all these O / W emulsifiers (polysorbate 80, disodium cetearyl sulfosuccinate, sodium stearoyl glutamate, and polyglycerol-10 stearate) can be used to form multiple emulsions. Furthermore, microscopic images of formulations 19 and 20 also showed multiple emulsion structures, providing insight that O / W emulsifier pairs (polyglycerol-10 oleate paired with cetearyl glucoside) can also form multiple emulsion structures. In contrast, microscopic images of formulations 16 and 17 showed non-spherical morphology, indicating that these combinations do not stabilize the internal W / O emulsions well.

[0116] To further optimize the dosage of the O / W emulsifier in the formulation, the formulation in Example 5 was prepared. Here, the inventors selected sodium stearoyl glutamate as the O / W emulsifier.

[0117] Example 5

[0118] This example demonstrates the appropriate dosage range of oil-in-water emulsifiers in formulations.

[0119] The composition of preparations 21 and 22 is listed in Table 6.

[0120] Table 6: Composition of preparations 21 and 22.

[0121]

[0122] The microstructure of each formulation was characterized by optical microscopy, and the results are shown in Table 11. Furthermore, the stability of the formulations is also recorded in Table 13.

[0123] The results showed that all formulations 15, 21, and 22 exhibited a multiple emulsion structure and passed a 3-month stability test. Therefore, the recommended dosage of sodium stearoyl glutamate is between 0.4% and 1.0%.

[0124] Example 6

[0125] This example demonstrates polymer compatibility in formulations.

[0126] The composition of preparations 23 and 24 is listed in Table 7.

[0127] Table 7: Composition of Preparations 23 and 24

[0128]

[0129] The microstructure of each formulation was characterized by optical microscopy, and the results are shown in Table 11. Furthermore, the stability of the formulations is also recorded in Table 13.

[0130] The results showed that all formulations 15, 23 and 24 exhibited a multi-emulsion structure and passed the 3-month stability test, indicating that the multi-emulsion structure has good compatibility with various polymers.

[0131] Example 7

[0132] This example demonstrates the appropriate range for W1 / O content in a preparation.

[0133] The composition of preparations 25 and 26 is listed in Table 8.

[0134] Table 8: Composition of Preparations 25 and 26

[0135]

[0136] The microstructure of each formulation was characterized by optical microscopy, and the results are shown in Table 11. Furthermore, the stability of the formulations is also recorded in Table 13.

[0137] The results showed that all formulations 15, 25 and 26 exhibited a multiple emulsion structure and passed a 3-month stability test, indicating that the W1 / O content in the formulations could be between 20% and 60%.

[0138] Example 8

[0139] This example demonstrates the manufacturing process of the preparation.

[0140] The composition and manufacturing process of preparations 27 to 31 are listed in Table 9.

[0141] Table 9: Composition and manufacturing process of preparations 27 to 31

[0142]

[0143] The microstructure of each formulation was characterized by optical microscopy, and the results are shown in Table 11. Furthermore, the stability of the formulations is also recorded in Table 13.

[0144] Except for the homogenization speed and duration in step 6 of the manufacturing process, the other steps remain the same as described above.

[0145] The results showed that formulation 27-30 exhibited a multi-emulsion structure and passed a 3-month stability test. The homogenization speed was between 3000-6000 rpm and the homogenization duration was between 3 and 10 minutes without compromising the structure and stability of the multi-emulsion.

[0146] Example 9

[0147] This example demonstrates the application of formulation technology.

[0148] The composition of preparations 32 and 33 is listed in Table 10.

[0149] Table 10: Composition of preparations 32 and 33.

[0150]

[0151] The microstructure of each formulation was characterized by optical microscopy, and the results are shown in Table 12. Furthermore, the stability of the formulations is also recorded in Table 13.

[0152] The results showed that formulations 32 and 33 exhibited a multiple emulsion structure and passed a 3-month stability test, indicating that both water-soluble and oil-soluble active ingredients can be encapsulated in multiple emulsions.

[0153] These application formulations exhibited multiple structures after being stored at 50°C, 40°C, and 25°C for 3 months, indicating that the structure of this multiple emulsion is stable.

[0154]

[0155] Table 12: Microstructure of formulations 32 and 33.

[0156]

[0157]

[0158] Sample stability

[0159] Unless otherwise stated, the stability of each preparation was evaluated by storing each preparation at 50°C, 40°C, 25°C and 5°C for 12 weeks, and its stability was rated according to the following criteria.

[0160]

[0161] Stability testing results showed that formulations 14, 15, 20-30, and 32-33 exhibited unexpectedly improved stability, and all of these formulations passed the 3-month stability test at 5°C, 25°C, 40°C, and 50°C.

Claims

1. A multi-emulsion composition comprising at least one water-in-oil emulsifier, at least one oil-in-water emulsifier, and at least one oil component; The water-in-oil emulsifier is selected from the group consisting of: polyglycerol fatty acid esters containing 2 to 6 glycerol units, esters or diesters of polyethylene glycol, straight-chain or branched silicone emulsifiers and mixtures thereof. The oil-in-water emulsifier is selected from the group consisting of: polyoxyethylene dehydrated sorbitol fatty acid ester, alkyl glucoside, N-acyl amino acid emulsifier, polyglycerol-10 fatty acid ester, monoester or diester of sulfosuccinate and mixtures thereof. This multiple emulsion is a water-in-oil-in-water emulsion.

2. The multiple emulsion according to claim 1, wherein, The water-in-oil emulsifier is selected from the group consisting of: polyglycerol fatty acid esters containing 2 to 6 glycerol units, esters or diesters of polyethylene glycol and mixtures thereof, preferably PEG-30 dihydroxystearate, polyglycerol polyhydroxystearate having 2 to 6 glycerol units, polyglycerol dihydroxystearate having 2 to 6 glycerol units, polyglycerol distearate / diisostearate having 2 to 6 glycerol units, polyglycerol polyricinoleate having 2 to 6 glycerol units and mixtures thereof; Preferably, the water-in-oil emulsifier is selected from the group consisting of: PEG-30 dihydroxystearate, polyglycerol-2 dihydroxystearate, polyglycerol-6 polyricinoleate, and mixtures thereof; More preferably, the water-in-oil emulsifier is selected from the group consisting of PEG-30 dihydroxystearate and combinations of PEG-30 dihydroxystearate and polyglycerol-2 dihydroxystearate.

3. The multiple emulsion according to claim 1, wherein, The oil-in-water emulsifier is selected from the group consisting of: N-acyl amino acid emulsifiers, polyglycerol-10 fatty acid esters, monoesters or diesters of sulfosuccinates and mixtures thereof; Preferably, the oil-in-water emulsifier is selected from the group consisting of: sodium stearoyl glutamate, sodium cocoyl glutamate, polyglycerol-10 stearate, polyglycerol-10 oleate, disodium cetearyl sulfosuccinate, and mixtures thereof. More preferably, the oil-in-water emulsifier is sodium stearoyl glutamate, disodium cetearyl sulfosuccinate, or a mixture thereof.

4. The multiple emulsion according to any one of claims 1 to 3, wherein, The water-in-oil emulsifier is present in an amount of 0.2% to 10% based on the total weight of the emulsion composition; wherein the oil-in-water emulsifier is present in an amount of 0.2% to 6.0% based on the total weight of the emulsion composition.

5. The multiple emulsion according to any one of claims 1 to 4, further comprising one or more adjuvants selected from the group consisting of: anti-wrinkle active agents, anti-acne active agents, emulsifiers, antioxidants, emollients, self-tanning active agents, skin whitening agents, sunscreens, UV absorbers, thickeners, humectants, abrasives, absorbents, fragrances, buffers, sunscreens, colorants, preservatives, fillers, pH adjusters, and solvents.

6. The multi-emulsion according to any one of claims 1 to 5, used in personal care or cosmetic formulations.

7. A method for preparing a stable water-in-oil-in-water emulsion, the method comprising i) preparing a water-in-oil emulsion, comprising mixing an oil phase comprising at least one water-in-oil emulsifier and at least one oil component with a first aqueous phase, and ii) mixing the water-in-oil emulsion obtained in step (i) with a second aqueous phase comprising at least one oil-in-water emulsifier, wherein the water-in-oil emulsifier is selected from the group consisting of: polyglycerol fatty acid esters comprising 2 to 6 glycerol units, (mono)esters or diesters of polyethylene glycol, linear or branched silicone emulsifiers; wherein the oil-in-water emulsifier is selected from the group consisting of: polyoxyethylene sorbitan fatty acid esters, N-acyl amino acid emulsifiers, polyglycerol-10 fatty acid esters, and monoesters or diesters of sulfosuccinates.

8. A method for preparing stable water-in-oil-in-water emulsions, wherein, Step (ii), which involves mixing the water-in-oil emulsion obtained in step (i) with the second aqueous phase, further includes a homogenization step, wherein the homogenization rate is between 3000 and 6000 rpm.

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