Emulsified system composition having phase inversion properties

Abstract

The present application provides an emulsified system composition with phase transition characteristics, comprising: an oil phase; an aqueous phase; and a ternary emulsifier system comprising a C12-20 alkyl glycoside nonionic emulsifier, a co-stabilizer and a hydrophilic nonionic emulsifier with an HLB greater than 10. After the composition of the present application is applied to the skin, under the combined action of skin temperature, application shear force and moisture evaporation, the system undergoes a controllable phase transition from oil-in-water to water-in-oil or even oil-continuous phase on the skin surface. The present application also relates to a skin external preparation comprising the emulsified system composition, and the skin external preparation is selected from the following forms: a face cream, a lotion, a gel, an essence, a mask, an eye cream.

Description

Technical Field

[0001] This invention belongs to the field of cosmetic technology, specifically relating to an emulsion system composition with a micro-molecular structure PIT phase transition. Background Technology

[0002] In the field of cosmetic research and development, emulsification technology is the core means to achieve the stable coexistence of oil phase, water phase, and functional ingredients. Its technical level directly determines the product's stability, skin feel, and efficacy delivery efficiency, and it is widely used in various skincare and makeup products such as creams, masks, and makeup removers. As consumers' skincare needs continue to upgrade, products with single functions and limited skin feel can no longer meet market expectations. Multifunctional products that combine cleansing, nourishing, and immediate beauty effects, along with excellent skin feel, have become a research and development hotspot in the industry.

[0003] Existing emulsification systems are mostly single-phase water-in-oil or oil-in-water structures, which cannot achieve phase transitions during use and thus cannot simultaneously meet the multiple needs of cleansing, nourishing, and immediate beauty. Although new precision emulsification technologies have improved stability and skin feel, most technologies still focus on particle size control to enhance ingredient penetration, without breaking through the limitations of fixed phases, and thus cannot achieve the dynamic experience of "cream-to-oil" and the multi-functional synergistic effect.

[0004] Consumers are increasingly demanding convenience, versatility, and superior skin feel from skincare products. There is an urgent need for a new type of emulsification system composition that can be formulated into a cream form with good spreadability and stability, and can undergo a phase transition during use. By leveraging the oil-transforming properties of creams, it can simultaneously achieve cleansing and makeup removal as well as nourishing and beautifying effects. This means it can dissolve facial makeup and dirt while replenishing the skin with nutrients, resulting in soft, supple, instantly radiant, and firm skin. This addresses the technical pain points of existing products, such as limited functionality, poor skin feel, and difficulty in simultaneously achieving cleansing and nourishment.

[0005] The invention patent (CN 119345068 A) provides a cream-to-oil composition, its preparation method, and its application. This composition can transform from a cream to an oil under heating conditions; for example, at the temperature provided by human skin, it can transform from a cream texture to an oil that can dissolve makeup. It also has good visual appeal, good moisturizing and brightening effects, leaves the skin feeling supple, and provides a pleasant user experience. It can be used as a cosmetic or in the preparation of cosmetic compositions. This composition comprises an aqueous phase, a thickening phase, and an oil phase. The thickening phase contains sodium polyacrylate, the oil phase contains various oils and multiple components, including behenyl alcohol polyether-25 as an emulsifier, and the aqueous phase contains water, alcohol, chelating agents, and preservatives. The composition has a complex number of components, and the preparation process is cumbersome. Furthermore, this patent limits the formulation to a cream form and does not extend to fluid emulsion formulations, thus its application scope is relatively narrow.

[0006] This invention unexpectedly discovered that an emulsification system composition consisting of cetearyl glucoside, glyceryl stearate, and PEG-100 stearate in a certain proportion has excellent emulsifying ability. It can prepare stable creams without the need for thickeners, and can prepare both fluid emulsions and thick creams. Moreover, the emulsions or creams prepared using this emulsification system composition can undergo a significant phase transition process at human skin temperature, that is, change from emulsion / cream to oil. After massage, it can not only dissolve and cleanse the skin, but also achieve a good moisturizing and hydrating effect, and brighten the skin. Summary of the Invention

[0007] On one hand, the present invention relates to an emulsion system composition having phase inversion properties, comprising: 15-20% by weight of oil phase; A 3-5% by weight ternary emulsifier system, wherein the ternary emulsifier system comprises a C12-20 alkyl glycoside nonionic emulsifier, a stabilizer, and a hydrophilic nonionic emulsifier with an HLB greater than 10; and Aqueous phase.

[0008] In a preferred embodiment, the alkyl glycoside nonionic emulsifier is cetearyl glucoside.

[0009] In a preferred embodiment, the stabilizer is glyceryl stearate.

[0010] In a preferred embodiment, the hydrophilic nonionic emulsifier is a polyethylene glycol fatty acid ester nonionic emulsifier, preferably PEG-100 stearate.

[0011] In a preferred embodiment, the weight ratio of C12-20 alkyl glycoside nonionic emulsifier: stabilizer: hydrophilic nonionic emulsifier in the ternary emulsifier system is 1.8:1.3:0.5.

[0012] In a preferred embodiment, the phase transition temperature (PIT) of the emulsifier system is 27°C to 35°C, and the phase transition time is 5.4-22.5 min, preferably 5.4-17 min.

[0013] In a preferred embodiment, after the composition of the present invention is applied to the skin, under the combined effects of skin temperature, application shear force, and water evaporation, the system undergoes a controllable phase transition on the skin surface from an oil-in-water type to an oil-in-water type or even an oil continuous phase.

[0014] On the other hand, the present invention also relates to a method for preparing an emulsion system composition as described in any one of claims 1-7, comprising: S1: Heat the aqueous phase to 75-80℃ to obtain solution 1; S2: Heat the ternary emulsifier system and the oil phase to 75-80℃ to obtain solution 2; S3: Add solution 2 to solution 1 and perform high-speed homogenization at a speed of 4000-5000 rpm for 8-15 minutes; S4: Defoaming and cooling yields a white cream.

[0015] In another aspect, the present invention also relates to a topical skin agent comprising the composition of the present invention, said topical skin agent being selected from the following forms: face cream, lotion, gel, serum, mask, eye cream. Brief description of the attached figures

[0016] Figure 1 The image shows the initial state of the composition prepared in Example 1 when applied to the skin (Figure a shows a milky white color) and the state after being left to stand for 10 minutes, when it transforms into an oily state (Figure b shows a transparent oily state).

[0017] Figure 2 The image shows the initial state of the composition prepared in Example 21 when applied to the skin (Figure a shows milky white) and the state after 10 minutes of rest (Figure b shows milky white).

[0018] Figure 3 The image shows the state of the composition prepared in Comparative Example 2 when applied to the skin.

[0019] Figure 4 The results of Example 1 are shown. (a) is a microscope image of the sample in its initial state; (b) is a microscope image of the sample taken after 5 minutes of application to human skin; (c) is a microscope image of the sample taken after 10 minutes of application to human skin.

[0020] Figure 5 A microscope image of the composition sample prepared in Example 21 is shown.

[0021] Figure 6 Microscopic images of the composition sample prepared in Comparative Example 2 are shown.

[0022] Figure 7 The DSC differential thermal analysis spectra of typical example samples are shown, including Examples 1, 8, 14 and 21. Detailed Implementation

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While any methods and materials similar or equivalent to those described herein may be used to practice or test the invention, preferred methods and materials are described herein. For the purposes of this invention, the following terms are defined.

[0024] As used herein, the term "about" means a quantity, level, value, dimension, size, or amount that differs from that of a reference by as much as 30%, 20%, or 10%. Percentages used herein, unless otherwise stated, are by weight.

[0025] Throughout this specification and claims, unless otherwise required, the words “comprising” and its variations “containing” and “including” shall be understood to mean including the said whole or step, or a group of whole or steps, but not excluding any other whole or step, or other group of whole or steps.

[0026] Ternary emulsifier system

[0027] This invention employs a ternary emulsifier system, in which the three components complement each other and exert a synergistic effect.

[0028] In some embodiments, the ternary emulsifier system comprises a C12-20 alkyl glycoside nonionic emulsifier, a stabilizer, and a hydrophilic nonionic emulsifier with an HLB greater than 10.

[0029] Alkyl glycoside nonionic emulsifiers are a class of green and environmentally friendly nonionic surfactants synthesized from sugars and fatty alcohols. They possess advantages such as mildness, easy biodegradability, acid and alkali resistance, and no cloud point, and are widely used in cosmetics, detergents, and personal care products. In a preferred embodiment, this invention uses a C16-C18 alkyl glycoside nonionic emulsifier. Specifically, the alkyl glycoside nonionic emulsifier used in this invention is cetearyl glucoside. Cetearyl glucoside is a typical alkyl glycoside emulsifier, belonging to long-chain (C16-C18) alkyl glycosides, and is commonly used in creams, lotions, and other skin care products as a primary or secondary emulsifier, forming a stable emulsion system and improving skin feel. Cetearyl glucoside can form a layered liquid crystal structure to encapsulate oil droplets, providing excellent stability and skin feel.

[0030] In a specific embodiment, the present invention uses cetearyl glucoside purchased from SEPPIC SA.

[0031] In some embodiments, the amount of alkyl glycoside nonionic emulsifier in the emulsification system composition of the present invention is 1-5% by weight, preferably 1-3% by weight, 1-2.5% by weight, 1.5-2.5% by weight, or 1.8-2.5% by weight.

[0032] Glyceryl stearate acts as a co-stabilizer in emulsion systems, primarily enhancing the physical stability of emulsions by forming layered gel networks and reducing oil-water interfacial tension. Glyceryl stearate is a lipophilic emulsifier and co-stabilizer, increasing the flexibility of the oil-water interfacial film.

[0033] In a specific embodiment, the present invention uses glyceryl stearate purchased from Zhejiang Wumart Biotechnology Co., Ltd.

[0034] In some embodiments, the amount of the stabilizer in the emulsified system composition of the present invention is 1-5% by weight, preferably 1-3% by weight, 1-2.5% by weight, 1-2% by weight, 1-1.5% by weight, or 1-1.3% by weight.

[0035] Hydrophilic nonionic emulsifiers have high HLB values ​​(typically >10), are readily soluble in water, and can form stable O / W emulsions. In a preferred embodiment, the hydrophilic nonionic emulsifier used in this invention is a polyethylene glycol fatty acid ester nonionic emulsifier. More preferably, this invention uses PEG-100 stearate as the hydrophilic nonionic emulsifier. PEG-100 stearate, as a hydrophilic nonionic emulsifier, improves the initial stability of the O / W emulsion.

[0036] In a specific embodiment, the present invention uses PEG-100 stearate purchased from Croda Singapore Pte Ltd.

[0037] In some embodiments, the amount of hydrophilic nonionic emulsifier in the emulsification system composition of the present invention is 0.5-1.5% by weight or 0.5-1% by weight.

[0038] In some embodiments, the compositions of the present invention comprise 3-5% by weight of a ternary emulsifier system. Preferably, the compositions of the present invention comprise 3-4% by weight or 3.6% by weight of a ternary emulsifier system.

[0039] In a preferred embodiment, the weight ratio of C12-20 alkyl glycoside nonionic emulsifier, co-stabilizer, and hydrophilic nonionic emulsifier in the ternary emulsifier system is 1.8:1.3:0.5.

[0040] In a preferred embodiment, the phase transition temperature (PIT) of the ternary emulsifier system is 27°C to 35°C, for example, 27°C to 34°C, 29°C to 35°C, 30°C to 35°C, 29°C to 34°C, or 30°C to 34°C.

[0041] In a preferred embodiment, the phase transition time of the ternary emulsifier system is 5.4-22.5 min, preferably 5.4-17 min.

[0042] Emulsion system composition

[0043] The purpose of this invention is to provide an emulsion system composition with phase transition properties. This composition has good formulation adaptability and can be used to prepare both fluid emulsions and thick creams. Emulsions or creams prepared using this emulsion system composition undergo a significant phase transition process under human skin temperature conditions—that is, from an initial white cream state to a transparent oil state, and are completely absorbed during continuous massage. The essence of this transition process is the dynamic process of the emulsion system transforming from an oil-in-water (O / W) emulsion to an oil-in-water (W / O) emulsion, and even to an oil-continuous phase, ultimately breaking down and spreading on the skin.

[0044] The phase transition process described in this invention is not driven by a single factor, but is triggered by the synergistic effect of four dimensions: temperature, shear force, water evaporation, and emulsifier properties. Specifically, the composition undergoes the following dynamic evolution stages after being applied to the skin: In the initial stage, the system exists in an O / W cream form, presenting a white, milky appearance; under the influence of skin temperature (32-35°C), the system temperature rises, and when approaching or crossing the PIT (phase inertia), the hydrophilic-lipophilic balance of the nonionic emulsifier shifts; simultaneously, the mechanical shear force during application lowers the phase transition energy barrier of the interfacial film, accelerating the phase reorganization process; as water continues to evaporate, the volume fraction of the aqueous phase gradually decreases, effectively further reducing the PIT of the system, allowing the phase transition conditions to be met within the skin temperature window; finally, the system transforms into an oil continuous phase, presenting a transparent, oily appearance, and achieves complete spread and absorption during subsequent massage. In this dynamic process, the oil phase efficiently dissolves facial makeup and dirt, while the oil-soluble active ingredients it carries are evenly deposited on the skin surface, thereby achieving simultaneous cleansing and moisturizing effects.

[0045] The compositions of the present invention comprise 15-20% by weight of an oil phase. In some embodiments, the oil phase is selected from squalane, caprylic / capric triglycerides, jojoba oil, and combinations thereof.

[0046] In a specific implementation, the present invention uses squalane purchased from Senris Biotechnology (Shenzhen) Co., Ltd.

[0047] In a specific embodiment, the present invention uses jojoba oil purchased from Vantage Specialty Chemicals, Inc.

[0048] In a specific implementation, the present invention uses caprylic / capric triglyceride purchased from BASF (China) Co., Ltd.

[0049] The composition of this invention forms a stable oil-in-water (O / W) emulsion cream in its initial state. The emulsifier combination employs three synergistic emulsifiers: cetearyl glucoside, an alkyl glycoside nonionic emulsifier that forms a layered liquid crystal structure to encapsulate oil droplets, providing excellent stability and a smooth feel; glyceryl stearate, a lipophilic emulsifier and stabilizer that increases the flexibility of the oil-water interface film; and PEG-100 stearate, a hydrophilic nonionic emulsifier that improves the initial stability of the O / W emulsion. In its initial state at room temperature, water is the continuous phase, and the oil droplets (squalane + fatty alcohol / ester) are encapsulated by a multilayered liquid crystal film. Light is strongly scattered at the oil-water interface, resulting in a white, opaque appearance.

[0050] When the cream of this invention comes into contact with the skin (32-35°C) and is gently applied, a phase transition process occurs. First, the increase in temperature triggers the "phase transition temperature" (PIT) mechanism; the hydrophilic-lipophilic balance (HLB) of the nonionic emulsifier is temperature-sensitive. As the temperature rises from room temperature to skin temperature, the polyoxyethylene chains or glycoside groups of PEG-100 stearate and alkyl glycosides dehydrate, decreasing their hydrophilicity. The system approaches the PIT, at which point the curvature of the interfacial film gradually changes from "water-in-oil" (hydrophilic curvature) to "oil-in-water" (lipophilic curvature). The emulsion type inverts. Second, shear forces and water evaporation promote the phase transition. The shearing action of manual application disrupts the metastable liquid crystal structure, allowing the inner phase (oil) to be released. The increased skin surface temperature accelerates water evaporation (approximately 5-10 minutes), reducing the volume fraction of the aqueous phase and forcing the continuous phase to transition from water to oil. Finally, a final state of oil continuous phase + micro-aqueous phase is formed, i.e., the phase transition is complete. Oily components such as squalane become the continuous phase, and the appearance becomes transparent (the refractive index of the oil phase matches that of air, and scattering disappears). At this point, a water-in-oil (W / O) emulsion or a bicontinuous phase is formed, with the aqueous phase dispersed in tiny droplets within the oil. Finally, the oil phase spreads and merges with the sebum film. Squalane is highly compatible with the skin's sebum, and its excellent spreadability allows it to quickly penetrate between the stratum corneum. The small amount of residual aqueous phase evaporates or emulsifies into the skin surface during massage, while glyceryl stearate and other components provide a soft, glossy feel.

[0051] Preparation method

[0052] This invention also relates to a method for preparing an emulsion system composition, comprising: S1: Heat the aqueous phase to 75-80℃ to obtain solution 1; S2: Heat the ternary emulsifier system and the oil phase to 75-80℃ to obtain solution 2; S3: Add solution 2 to solution 1 and perform high-speed homogenization at a speed of 3000-5000 rpm for 8-15 min; S4: Defoaming and cooling yields a white cream.

[0053] In a preferred embodiment, the homogenization speed in S3 is 3500-5000 rpm or 4000-5000 rpm.

[0054] In a preferred embodiment, the emulsified system composition of the present invention does not contain additional emulsifiers.

[0055] In a preferred embodiment, the emulsified system composition of the present invention does not contain any additional thickener.

[0056] Topical skin agents

[0057] The compositions of the present invention can be used in topical skin preparations.

[0058] In some embodiments, the composition of the present invention is present in a topical skin agent at a concentration of 10-99% by weight, preferably 10-95% by weight, 10-90% by weight, 10-85% by weight, 10-80% by weight, 10-70% by weight, 10-60% by weight, 10-50% by weight, 20-99% by weight, preferably 20-95% by weight, 20-90% by weight, 20-85% by weight, 20-80% by weight, 20-70% by weight, 20-60% by weight, 20-50% by weight, 30-99% by weight, preferably 30-95% by weight. 30-90 wt%, 30-85 wt%, 30-80 wt%, 30-70 wt%, 30-60 wt%, 30-50 wt%, 40-99 wt%, preferably 40-95 wt%, 40-90 wt%, 40-85 wt%, 40-80 wt%, 40-70 wt%, 40-60 wt%, 40-50 wt%, 50-99 wt%, preferably 50-95 wt%, 50-90 wt%, 50-85 wt%, 50-80 wt%, 50-70 wt%, 50-60 wt%.

[0059] In some embodiments, the composition of the present invention is present in a topical skin agent at a concentration of 0.0001-10% by weight, preferably 0.0001-8% by weight, 0.0001-5% by weight, 0.0001-3% by weight, 0.0001-2% by weight, 0.0001-1% by weight, 0.001-8% by weight, 0.001-5% by weight, 0.001-3% by weight, 0.001-2% by weight, 0.001-1% by weight, 0.01-8% by weight, 0.01-5% by weight, 0.01-3% by weight, 0.01-2% by weight, 0.01-1% by weight, 0.1-8% by weight, 0.1-5% by weight, 0.1-3% by weight, 0.1-2% by weight, and 0.1-1% by weight.

[0060] In some embodiments, the topical skin agent is selected from: face creams, lotions, gels, toners, serums, face masks, eye creams, aerosols (cleansing foams), shower gels, and facial cleansers. Different dosages are added depending on the type of formulation.

[0061] The term "topical skin agent" is a general term encompassing all ingredients typically used on the external surface of the skin, such as cosmetic compositions. These cosmetic compositions can include basic cosmetics, facial makeup cosmetics, body cosmetics, hair care cosmetics, etc., with no specific restrictions on their dosage forms; they can be rationally selected according to different purposes. Depending on the dosage form and purpose, these cosmetic compositions may also contain different cosmetically permissible media or matrix excipients.

[0062] Topical skin preparations contain dermatologically acceptable carriers or mediators (e.g., lotions, creams, ointments, cleansers, etc.). Those skilled in the art can select carriers capable of dissolving or dispersing these components at the concentrations described above, based on common knowledge in the art. When using a carrier, it should not cause inactivation of the compositions of the invention and should not produce any adverse effects on the skin during application.

[0063] Those skilled in the art can select suitable carriers based on common knowledge and their ability to dissolve or disperse in the active component at the concentration most suitable for processing, such as water, alcohols, oils, etc.

[0064] The topical skin agents of the present invention can be in the form of topical application products that can be applied externally to the skin and can be prepared using common techniques known in the art. The carrier can have various practical forms, such as creams, dressings, gels, lotions, ointments, or liquids, including compositions that are applied and washed off, and materials incorporated into them using methods known in the art, such as dry or wet applicators, hydrogel matrices, or adhesive (or non-adhesive) patches. Preferably, the carrier is a gel or a moisture-enhancing lotion, or an applicator in dry or wet form.

[0065] Typical carriers include emulsions containing water and / or alcohols and emollients, where the emollients are, for example, oils and waxes of hydrocarbons, silicone oils, hyaluronic acid, fats or oils from plants, animals, or marine organisms, glyceryl ester derivatives, fatty acids, or fatty acid esters or alcohols or alcohol ethers, lanolin and its derivatives, polyols or esters, wax esters, sterols, phospholipids, etc., and generally include emulsifiers (nonionic, cationic, or anionic), although some emollients themselves have emulsifying properties. Additionally, these same components can be formulated into creams, gels, or solid bars by utilizing different proportions of their components and / or by incorporating thickeners such as gums or other forms of hydrophilic colloids.

[0066] The topical skin preparations of the present invention may include additional components commonly found in skin care compositions, such as emollients, skin conditioners, emulsifiers, preservatives, antioxidants, fragrances, chelating agents, etc., provided that they are physically and chemically compatible with other components in the topical skin preparations and do not affect the efficacy of the compositions of the present invention.

[0067] In some embodiments of the topical skin formulation of the present invention, one or more preservatives may be used. Suitable preservatives include p-hydroxyacetophenone, C1-C4 alkyl p-hydroxybenzoate, and phenoxyethanol. Based on the total weight of the composition, the amount of preservative used is from about 0.5 to about 2% by weight, preferably from about 0.5 to 1% by weight.

[0068] In one example of the topical skin preparation of the present invention, one or more antioxidants may be used. Suitable antioxidants include butylated hydroxytoluene (BHT), ascorbyl palmitate (BHA), butylated hydroxyanisole, phenyl-α-naphthylamine, hydroquinone, propyl gallate, nordihydroguaiac acid, vitamin E or a derivative of vitamin E, vitamin C and its derivatives, calcium pantothenate, green tea extract, and mixed polyphenols, as well as mixtures of the substances described above. The antioxidant used is approximately 0.02 to 0.5% by weight of the total weight of the composition, more preferably in the range of approximately 0.002 to 0.1% by weight.

[0069] In one example of the topical skin preparation of the present invention, one or more emollients may be used, which, by virtue of their ability to remain on the skin surface or in the stratum corneum, act as lubricants to reduce exfoliation and improve the appearance of the skin. Typical emollients include fatty esters, fatty alcohols, mineral oils, polyether silicone copolymers, and the like. Examples of suitable emollients, not limited to, include polypropylene glycol (“PPG”)-15 octadecyl ether, PPG-10 hexadecyl ether, Steareth-10, Oleth-8, PPG-4 dodecyl ether, vitamin E acetate, lanolin, cetyl alcohol, cetearyl alcohol ethylhexanoate, cetearyl alcohol, glyceryl stearate, octyl hydroxystearate, dimethyl polysiloxane, and combinations thereof. Cetyl alcohol, cetearyl alcohol ethylhexanoate, cetearyl alcohol, glyceryl stearate, and combinations thereof are preferred. When used, the emollient is applied in an amount ranging from about 0.1% to about 30% by weight, preferably from about 1% to about 30% by weight, based on the total weight of the composition.

[0070] In one example of the topical skin preparation of the present invention, one or more moisturizers may be used. Moisturizers, also known as humectants, help enhance the effectiveness of emollients, reduce exfoliation, stimulate the removal of scaly skin, and improve skin feel. Polyols may be used as moisturizers, including, but not limited to, glycerin, polyalkylene glycols, alkylene polyols and their derivatives, including butylene glycol, propylene glycol, dipropylene glycol, glycerol, polyethylene glycol and their derivatives, sorbitol, hydroxypropyl sorbitol, hexanediol, 1,3-dibutylene glycol, 1,2,6-hexanetriol, ethoxylated glycerin, propoxylated glycerin, and combinations thereof. When used, the amount of moisturizer is from about 0.1% to about 20% by weight, preferably from about 1% to about 15% by weight, based on the total weight of the composition.

[0071] In one example of the topical skin formulation of the present invention, one or more emulsifiers may be used. The emulsifier may be used within a range of effective stable amounts. Preferably, the emulsifier is used at an amount of about 1.0 to about 10.0% by weight, more preferably about 3.0 to about 6.0% by weight, based on the total weight of the composition. Any emulsifier compatible with the components in the composition may be used. Suitable emulsifiers include stearic acid, cetyl alcohol, glyceryl stearate, lecithin, octadecyl alcohol, Steareth-2, Steareth-20, acrylate / C10-30 alkanol acrylate crosspolymers, and combinations thereof.

[0072] In one example of the topical skin formulation of the present invention, one or more pH adjusters may be used. Beneficial pH adjusters in the topical skin formulation of the present invention include tromethamine. When used, the amount of pH adjuster is approximately 0.1 to approximately 2% by weight, preferably approximately 0.1 to approximately 1% by weight, based on the total weight of the composition.

[0073] In one specific embodiment of the invention, the topical skin agent comprises an acrylate / C10-30 alkanol acrylate crosspolymer, glycerin, p-hydroxyacetophenone, glyceryl stearate and lecithin, cetearyl alcohol, cetearyl ethylhexanoate, tromethamine or a combination thereof.

[0074] In some embodiments of the present invention, the amount of the composition of the present invention in the topical skin preparation is 0.001%-20% (w / w), preferably 0.01%-20% (w / w), more preferably 0.01%-10% (w / w), and most preferably 0.1%-5% (w / w).

[0075] In one specific embodiment of the present invention, the amount of the composition of the present invention in the topical skin preparation is 0.1-5% by weight. In a preferred embodiment, the amount of the composition of the present invention in the topical skin preparation is 0.13% by weight.

[0076] Example

[0077] The present invention will be further illustrated below with reference to specific embodiments. It is important to note that these embodiments are for illustrative purposes only and should not be construed as limiting the scope of protection of the invention. Those skilled in the art can make non-essential improvements and adjustments based on the above description of the invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the manufacturer. Unless otherwise stated, all percentages and parts are by weight.

[0078] Experimental materials: 1. Glyceryl stearate, white solid, purchased from Zhejiang Wumart Biotechnology Co., Ltd.; 2. PEG-100 stearate, a white waxy solid, purchased from Croda Singapore Pte Ltd; 3. Cetearyl glucoside, a white solid granule, purchased from SEPPIC SA; 4. Cetearyl alcohol, a white solid granule, purchased from Edenor Oleochemicals (M) Sdn. Bhd.; 5. Squalane, a colorless and transparent liquid, was purchased from Senris Biotechnology (Shenzhen) Co., Ltd. 6. Jojoba oil, a colorless to slightly yellow liquid, purchased from Vantage Specialty Chemicals, Inc.; 7. Caprylic / capric triglyceride, a colorless to pale yellow transparent liquid, purchased from BASF (China) Co., Ltd.; 8. Tween 80 (polysorbate-80), a clear yellow liquid, was purchased from Croda Singapore Pte Ltd.; 9. Span 60 (sorbitan stearate), a white to yellow solid, purchased from Croda Singapore Pte Ltd.

[0079] Experimental apparatus: 1. Weighing balance METTLER TOLEDO PL602-S; 2. Fixed mixer IKA RW20; 3. Electric thermostatic water bath, Shanghai Yiheng Scientific Instruments Co., Ltd., HWS 28 model; 4. Electric thermostatic CO2 incubator (Thermo, 150i); 5. Differential thermal analyzer (DSC), DSC4000, PerkinElmer. 6. Upright microscope (Olympus, BX53).

[0080] Example 1

[0081] Weigh 76.4g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 1.8g of cetearyl glucoside, 1.3g of glyceryl stearate, 0.5g of PEG-100 stearate, and 20g of plant squalane to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 4000 rpm for 9 minutes. After homogenization, degas the solution, stir (300 rpm), and cool to room temperature to obtain a white cream for later use.

[0082] Example 2

[0083] Weigh 81.4g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 1.8g of cetearyl glucoside, 1.3g of glyceryl stearate, 0.5g of PEG-100 stearate, and 15g of plant squalane to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 4000 rpm for 9 min. After homogenization, degas the solution, stir (300 rpm), and cool to room temperature to obtain a white cream for later use.

[0084] Example 3

[0085] Weigh 71.4g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 1.8g of cetearyl glucoside, 1.3g of glyceryl stearate, 0.5g of PEG-100 stearate, and 25g of plant squalane to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 4000 rpm for 9 min. After homogenization, degas the solution, stir (300 rpm), and cool to room temperature to obtain a white cream for later use.

[0086] Example 4

[0087] Weigh 66.4g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 1.8g of cetearyl glucoside, 1.3g of glyceryl stearate, 0.5g of PEG-100 stearate, and 30g of plant squalane to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 4000 rpm for 9 min. After homogenization, degas the solution, stir (300 rpm), and cool to room temperature to obtain a white cream for later use.

[0088] Example 5

[0089] Weigh 76.4g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 1.8g of cetearyl glucoside, 1.3g of glyceryl stearate, 0.5g of PEG-100 stearate, 10g of plant squalane, and 10g of caprylic / capric triglyceride (GTCC) to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 4000 rpm for 9 min. After homogenization, degas the solution, stir (300 rpm), and cool to room temperature to obtain a white cream for later use.

[0090] Example 6

[0091] Weigh 76.4g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 1.8g of cetearyl glucoside, 1.3g of glyceryl stearate, 0.5g of PEG-100 stearate, and 20g of caprylic / capric triglyceride (GTCC) to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 4000 rpm for 9 min. After homogenization, degas the solution, stir (300 rpm), and cool to room temperature to obtain a white cream for later use.

[0092] Example 7

[0093] Weigh 76.4g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 1.8g of cetearyl glucoside, 1.3g of glyceryl stearate, 0.5g of PEG-100 stearate, 10g of jojoba oil, and 10g of plant squalane to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 4000 rpm for 9 min. After homogenization, degas the solution, stir (300 rpm), and cool to room temperature to obtain a white cream for later use.

[0094] Example 8

[0095] Weigh 75.9g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 1.8g of cetearyl glucoside, 1.3g of glyceryl stearate, 1.0g of PEG-100 stearate, and 20g of plant squalane to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 4000 rpm for 9 min. After homogenization, degas the solution, stir (300 rpm), and cool to room temperature to obtain a white cream for later use.

[0096] Example 9

[0097] Weigh 76.0g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 2.5g of cetearyl glucoside, 1.0g of glyceryl stearate, 0.5g of PEG-100 stearate, and 20g of plant squalane to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 4000 rpm for 9 min. After homogenization, degas the solution, stir (300 rpm), and cool it to room temperature to obtain a white cream for later use.

[0098] Example 10

[0099] Weigh 76.2g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 1.5g of cetearyl glucoside, 0.3g of PEG-7 olive oil ester, 1.5g of glyceryl stearate, 0.5g of PEG-100 stearate, and 20g of plant squalane to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 4000 rpm for 9 min. After homogenization, degas the solution, stir (300 rpm), and cool to room temperature to obtain a white cream for later use.

[0100] Example 11

[0101] Weigh 76.4g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 1.8g of cetearyl glucoside, 1.3g of glyceryl stearate, 0.5g of PEG-100 stearate, and 20g of plant squalane to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 3000 rpm for 10 minutes. After homogenization, degas the solution, stir (300 rpm), and cool to room temperature to obtain a white cream for later use.

[0102] Example 12

[0103] Weigh 76.4g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 1.8g of cetearyl glucoside, 1.3g of glyceryl stearate, 0.5g of PEG-100 stearate, and 20g of plant squalane to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 5000 rpm for 8 minutes. After homogenization, degas the solution, stir (300 rpm), and cool to room temperature to obtain a white cream for later use.

[0104] Example 13

[0105] Weigh 71.4g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 1.8g of cetearyl glucoside, 1.3g of glyceryl stearate, 0.5g of PEG-100 stearate, 12.5g of plant squalane, and 12.5g of GTCC to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 3500 rpm for 10 minutes. After homogenization, degas the solution, stir (300 rpm), and cool to room temperature to obtain a white cream for later use.

[0106] Example 14

[0107] Weigh 70.9g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 1.8g of cetearyl glucoside, 1.3g of glyceryl stearate, 1.0g of PEG-100 stearate, and 25g of GTCC to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 5000 rpm for 8 minutes. After homogenization, degas the solution, stir (300 rpm), and cool it to room temperature to obtain a white cream for later use.

[0108] Example 15

[0109] Weigh 66.0g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 2.5g of cetearyl glucoside, 1.0g of glyceryl stearate, 0.5g of PEG-100 stearate, and 30g of plant squalane to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 3000 rpm for 10 min. After homogenization, degas the solution, stir (300 rpm), and cool it to room temperature to obtain a white cream for later use.

[0110] Example 16

[0111] Weigh 76.2g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 1.5g of cetearyl glucoside, 0.3g of PEG-7 olive oil ester, 1.5g of glyceryl stearate, 0.5g of PEG-100 stearate, 10g of plant squalane, and 10g of jojoba oil to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 5000 rpm for 8 min. After homogenization, degas the solution, stir (300 rpm), and cool to room temperature to obtain a white cream for later use.

[0112] Example 17

[0113] Weigh 80.9g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 1.8g of cetearyl glucoside, 1.3g of glyceryl stearate, 1.0g of PEG-100 stearate, and 15g of plant squalane to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 5000 rpm for 8 min. After homogenization, degas the solution, stir (300 rpm), and cool to room temperature to obtain a white cream for later use.

[0114] Example 18

[0115] Weigh 66.0g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 2.5g of cetearyl glucoside, 1.0g of glyceryl stearate, 0.5g of PEG-100 stearate, and 30g of caprylic / capric triglyceride (GTCC) to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 3500 rpm for 10 min. After homogenization, degas the solution, stir (300 rpm), and cool to room temperature to obtain a white cream for later use.

[0116] Example 19

[0117] Weigh 81.4g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 1.8g of cetearyl glucoside, 1.3g of glyceryl stearate, 0.5g of PEG-100 stearate, 7.5g of plant squalane, and 7.5g of GTCC to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 3500 rpm for 10 minutes. After homogenization, degas the solution, stir (300 rpm), and cool to room temperature to obtain a white cream for later use.

[0118] Example 20

[0119] Weigh 76.4g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 1.8g of cetearyl glucoside, 1.3g of glyceryl stearate, 0.5g of PEG-100 stearate, and 20g of plant squalane to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 4000rpm for 9min. After homogenization, degas the solution with ultrasound for 2min instead of normal static degassing, stir (300rpm), and cool to room temperature to obtain a white cream for later use.

[0120] Example 21

[0121] Weigh 76.2g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 1.8g of cetearyl glucoside, 0.2g of cetearyl alcohol, 1.3g of glyceryl stearate, 0.5g of PEG-100 stearate, and 20g of plant squalane to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 4000rpm for 9min. After homogenization, degas the solution, stir (300rpm), and cool to room temperature to obtain a white cream for later use.

[0122] Comparative Example 1

[0123] Weigh 76.4g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 3.6g of glyceryl stearate and 20g of plant squalane to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 4000rpm for 9min. After homogenization, degas the solution, stir (300rpm), and cool it to room temperature to obtain a demulsified, unstable emulsion for later use.

[0124] Comparative Example 2

[0125] Weigh 76.4g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 3.6g of PEG-100 stearate and 20g of plant squalane to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 4000rpm for 9min. After homogenization, degas the solution, stir (300rpm), and cool it to room temperature to obtain a white cream for later use.

[0126] Comparative Example 3

[0127] Weigh 76.4g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 3.6g of cetearyl glucoside and 20g of plant squalane to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 4000rpm for 9min. After homogenization, degas the solution, stir (300rpm), and cool it to room temperature to obtain a white cream for later use.

[0128] Comparative Example 4

[0129] Weigh 76.4g of deionized water in a beaker and heat it to 75-80℃ to obtain solution 1. In another beaker, heat 3.0g of Tween 80, 0.6g of Span 60, and 20g of plant squalane to 75-80℃ until completely dissolved to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 4000rpm for 9min. After homogenization, degas the solution, stir (300rpm), and cool it to room temperature to obtain a white cream for later use.

[0130] Comparative Example 5

[0131] Weigh 80g of deionized water in a beaker and heat it to 60℃ to obtain solution 1. In another beaker, heat 20g of plant squalane to 60℃ and dissolve it completely to obtain solution 2. Slowly add solution 2 to the aqueous phase of solution 1 and homogenize at 4000 rpm for 9 minutes. After homogenization, degas the solution, stir (300 rpm), and cool it to room temperature to obtain an unstable, layered liquid for later use.

[0132] Comparative Example 6

[0133] Comparative Example 6 was prepared according to Example 1 of CN 119345068 A.

[0134] A frost-to-oil composition and its preparation method are disclosed. The formulation of the frost-to-oil composition is shown in the table below.

[0135] The preparation method of the frost-to-oil composition includes: (1) stirring and dispersing the raw materials in the aqueous phase evenly; (2) adding a thickening phase to the aqueous phase after dispersion in step (1), dispersing evenly, and heating to 80°C; (3) adding the oil phase...

[0136] (3) Mix and heat the raw materials to 80°C; (4) Add the oil phase from step (3) to the water phase from step (2) for homogenization at 80°C, 3000 rpm for 6 min, and stir and cool down to 40°C after homogenization; (5) Add the active phase and pH adjustment phase, homogenize at 3000 rpm for 6 min, and stir and cool down to 30°C after homogenization; (6) Defoaming treatment to obtain the frost-to-oil composition.

[0137]

[0138] Test Example 1: Consumer Trial Test

[0139] Based on the skin performance of the sample compositions obtained in the above embodiments and comparative examples, the following consumer testing method was developed.

[0140] The purpose of the test was to evaluate the phase transition phenomenon, spreadability, absorption rate, and post-use skin feel of the sample on the skin. Thirty healthy adult subjects (half male and half female, aged 25-55 years) were selected. The back of the hand was used as the test area. Subjects were required to have no skin lesions or diseases and had not used any skincare products within 24 hours prior to the test. The test environment was controlled at a temperature of 22±1℃ and a relative humidity of 50±5%. Subjects washed and dried their hands with neutral soap before the test and remained in the temperature and humidity controlled chamber for 30 minutes to acclimatize.

[0141] Using a disposable sampling spoon, take approximately 0.5g (about the size of a soybean) of sample and place it on a 4×4cm area on the back of the hand. Use the ring finger to evenly spread the sample in 10 circular motions at approximately 1 revolution per second. Immediately after application, record the initial appearance and start timing. Observe the sample's condition with the naked eye and under a 5000K standard light source at 0, 2, 5, 10, and 15 minutes after application: record the color, shape, and whether there is any residue. At the 10-minute mark, if the sample has turned into a transparent oil, the subject should gently massage the area in circular motions for 15 seconds using the middle and ring fingers of their other hand. Then assess the absorption (complete absorption, partial absorption, no absorption) and evaluate the skin's softness and shine by touch. Each subject should undergo the test three times, with at least 2 hours between each test (after washing and allowing the subject to acclimatize).

[0142] Results statistics: The average time for subjects to completely transform into a transparent oil, the rate of complete absorption after 15 seconds of massage, and the percentage of subjects who felt their skin was soft and radiant were calculated. Subjects were rated on a scale of 0-5, with higher scores indicating greater acceptance. Any discomfort (such as stinging, burning, redness, etc.) was also recorded. The final report should include subject demographic information, testing conditions, descriptions of appearance changes at each time point, absorption rate, and the mean and standard deviation of skin feel evaluations. This method can be used to evaluate the phase transition properties of samples under skin temperature and moisture conditions, as well as end-consumer acceptance.

[0143]

[0144] Figure 1 The image shows the initial state of the composition prepared in Example 1 when applied to the skin (Figure a shows a milky white color) and the state after being left to stand for 10 minutes, when it transforms into an oily state (Figure b shows a transparent oily state).

[0145] Figure 2 The image shows the initial state of the composition prepared in Example 21 when applied to the skin (Figure a shows milky white) and the state after 10 minutes of rest (Figure b shows milky white).

[0146] Figure 3 The image shows the state of the composition prepared in Comparative Example 2 when applied to the skin.

[0147] The above examples and comparative examples cover variations in oil phase type and dosage, emulsifier hydrophilic-lipophilic balance, homogenization shear strength, and auxiliary components. Orthogonal analysis can identify key factors affecting phase inversion performance. The comparative examples, by removing or replacing key emulsifiers and changing process temperatures, highlight the innovation of the ternary emulsification system and high-temperature homogenization of this invention in achieving the "white → transparent → fully absorbed" effect.

[0148] This invention unexpectedly discovered that a stable oil-in-water (O / W) emulsion cream is formed in its initial state. The emulsifier combination employs the synergistic effect of three emulsifiers: cetearyl glucoside, an alkyl glycoside nonionic emulsifier that forms a layered liquid crystal structure to encapsulate oil droplets, providing excellent stability and a smooth feel; glyceryl stearate, a lipophilic emulsifier and stabilizer that increases the flexibility of the oil-water interface film; and PEG-100 stearate, a hydrophilic nonionic emulsifier that improves the initial stability of the O / W emulsion. In its initial state at room temperature, water is the continuous phase, and the oil droplets (squalane + fatty alcohol / ester) are encapsulated by a multilayered liquid crystal film. Light is strongly scattered at the oil-water interface, resulting in a white, opaque appearance.

[0149] The phase transition process of the composition sample in Example 1 after application to the skin is quite remarkable. When the cream comes into contact with the skin (32-35℃) and is gently applied, the following changes occur sequentially: 1) The temperature rise triggers a "phase inversion temperature" (PIT) mechanism. PIT is a phase transition phenomenon of emulsions based on the temperature-responsive characteristics of nonionic surfactants. The hydrophilic-lipophilic balance (HLB) of nonionic emulsifiers is temperature-sensitive. As the temperature rises from room temperature to skin temperature, the polyoxyethylene chains or glycoside groups of PEG-100 stearate and alkyl glycosides dehydrate, and their hydrophilicity decreases. The system approaches the phase transition temperature (PIT), at which point the curvature of the interfacial film gradually changes from "water-in-oil" (hydrophilic curvature) to "oil-in-water" (lipophilic curvature). The emulsion type reverses. 2) Shear force and water evaporation promote phase inversion. The shearing action of manual application disrupts the metastable liquid crystal structure, allowing the inner phase (oil) to be released. Skin surface temperature accelerates water evaporation (approximately 5-10 minutes), reducing the volume fraction of the aqueous phase and forcing the continuous phase to transform from water to oil. 3) The final state of the oil continuous phase + micro-aqueous phase, i.e., after phase inversion, oily components such as squalane and cetearyl alcohol become the continuous phase, appearing transparent (the refractive index of the oil phase matches that of air, and scattering disappears). At this point, a water-in-oil (W / O) emulsion or a bicontinuous phase is formed, with the aqueous phase dispersed in the oil as tiny droplets. 4) The oil phase spreads and integrates with the sebum film. Squalane is highly compatible with skin sebum, and its excellent spreadability allows it to quickly penetrate between the stratum corneum. The remaining small amount of aqueous phase evaporates or emulsifies into the skin surface during massage, while glyceryl stearate and other components provide a soft, glossy feel. Theoretically, this system is a temperature-shear-volatility triple-induced PIT-type phase inversion emulsion. Analysis based on actual observed phenomena, such as Figure 1This demonstrates the self-consistency of the theoretical prediction. The initial state of the composition prepared in Example 1 applied to the skin (Figure a: milky white) and its transformation to an oily state after 10 minutes of rest (Figure b: transparent oil) are shown. This phenomenon can be altered by changing the emulsifier composition. For example, in Example 21, the initial state of the composition applied to the skin (Figure a: milky white) and its transformation to an oily state after 10 minutes of rest (Figure b: milky white) did not show a PIT phase transition. In this example, only a "small amount" of cetearyl alcohol was added, resulting in a significant change in the PIT temperature, or even no phase transition at all. Figure 3 Comparative Example 2 shows that the cream, which cannot form a stable performance on the hand, is even less likely to experience a phase transition phenomenon.

[0150] Test Example 2: Observation with an optical microscope

[0151] The Olympus BX53 microscope was used to photograph the samples of the above examples and comparative examples. The standard operation includes four steps: slide preparation, adjustment, observation, and image acquisition. For slide preparation, a small amount of sample is placed on the left side of a clean glass slide. Using a coverslip to hold the slide in place, the sample is gently pushed into an extremely thin, scratch-free, and uniformly transparent coating (because the coverslip may deform the oil droplets and affect particle size measurement, in some scenarios, the slide can be pushed directly without a coverslip for observation). Observation should be completed as soon as possible before the sample dries. Before operating the equipment, the microscope is placed on a stable stage. The power to the microscope and image acquisition unit is turned on, and the transmitted light source is turned on and the light intensity is adjusted to medium brightness (approximately 50%). The slide containing the sample is then placed stably on the stage and secured with a specimen clip. The stage movement knob is rotated to align the slide pushing area with the center of the light aperture. The objective lens is selected using the 40× low-power objective lens by rotating the objective lens dial. The sample is brought into the field of view using the coarse focus knob, and then fine focus is achieved using the fine focus knob. After confirming that the real-time preview image is clear, double-click the desktop image acquisition software (such as CellSens Entry) to enter the operation interface. Click the "Real-time Observation" button and adjust the exposure time and resolution according to the sample texture. Finally, click the "Take Photo" button to save the image to the specified folder. After taking the photo, turn the objective lens to an empty position, set the light intensity to minimum, turn off the power, remove the slide, clean the stage, and cover it with the dust cover. Ensure the equipment is returned to its proper place.

[0152] Figure 4 The results of Example 1 are shown. (a) is a microscope image of the sample in its initial state; (b) is a microscope image of the sample taken after 5 minutes of application to human skin; (c) is a microscope image of the sample taken after 10 minutes of application to human skin.

[0153] Figure 5 A microscope image of the composition sample prepared in Example 21 is shown.

[0154] Figure 6Microscopic images of the composition sample prepared in Comparative Example 2 are shown.

[0155] Microscopic images can further prove the correctness of the above-mentioned PIT phase inversion theory. From Figure 4 Typical Example 1, (a) is a microscope image of the initial state of the prepared sample; (b) is a microscope image of the sample taken after 5 minutes of application to human skin; (c) is a microscope image of the sample taken after 10 minutes of application to human skin. It can be seen that shear force and water evaporation promote phase inversion. The shearing action of manual application disrupts the metastable molecular microstructure, allowing the inner phase (oil) to be released. Skin surface temperature accelerates water evaporation (approximately 5-10 minutes), reducing the volume fraction of the aqueous phase. Figure 4 (b) forces the continuous phase to transform from water to oil. The final state of the oil continuous phase + micro-aqueous phase, i.e., after phase transformation, is that oily components such as squalane and cetearyl alcohol become the continuous phase, and the appearance becomes transparent (the refractive index of the oil phase matches that of air, and scattering disappears). Figure 4 c). At this point, a water-in-oil (W / O) emulsion or a bicontinuous phase is formed, with the aqueous phase dispersed in the oil as tiny droplets. Figure 5 and Figure 6 In the examples and comparative examples, no similar phase inversion phenomenon can be observed.

[0156] Test Example 3: Differential Scanning Calorimetry (DSC) for measuring the phase transition temperature of a sample.

[0157] By measuring the heat flow difference between the sample and the reference under programmed temperature control, the phase transition behavior of the composition samples obtained in the examples and comparative examples is analyzed, and the phase transition temperature and enthalpy value are obtained.

[0158] A DSC4000 differential thermal analyzer equipped with a mechanical refrigeration system (temperature accuracy within ±0.1℃, heat flux accuracy within ±0.2μW), an analytical balance with an accuracy of 0.0001g, a sealed aluminum crucible and tablet press, nitrogen (purity ≥99.999%), and standard calibration materials (indium and zinc) were used. A homogeneous representative sample was taken from the test sample, and 10mg was accurately weighed using the analytical balance and placed into an aluminum crucible. The crucible was then sealed using the tablet press to prevent moisture evaporation. An empty aluminum crucible was prepared as a reference. Instrument calibration was performed before the formal test: three baseline tests were run and the average was taken; then, two-point temperature calibration was performed using indium (melting point 156.6℃) and zinc (melting point 419.5℃) to ensure a temperature error ≤±0.1℃; and the enthalpy was calibrated using indium standard materials to ensure the phase transition enthalpy measurement accuracy was within ±1%. The test atmosphere was high-purity nitrogen, with a flow rate set at 50 mL / min to provide an inert environment and stabilize the heat flux signal. A three-stage temperature program was employed: the first stage involved heating from 0°C (or lower to -10°C, depending on the low-temperature composition of the sample) to 90°C at a rate of 5°C / min, ensuring the sample was in a uniform initial state; the second stage involved cooling from 90°C to 0°C at a rate of 5°C / min, observing phase formation and supercooling during the cooling process; the third stage involved heating from 0°C back to 90°C at a rate of 2–5°C / min, which was the stage for formally acquiring the phase transition characteristic peaks—a lower heating rate (e.g., 2–5°C / min) helped separate adjacent phase transition peaks, avoiding the omission of intermediate phase information due to peak overlap. During data analysis, the phase transition onset temperature (T_onset, the critical point of deviation from the baseline), peak temperature (T_peak, the point of fastest transition rate), end temperature (T_endset, the point of return to the baseline), and phase transition enthalpy (ΔH, peak area) were extracted from the DSC curve. This method is applicable to the determination of phase transition temperatures of skincare product samples with specific structures, and can provide reliable thermal analysis data for formulation optimization and quality control.

[0159] Figure 7 The DSC differential thermal analysis spectra of typical example samples are shown, including Examples 1, 8, 14 and 21.

[0160] From a theoretical analysis perspective, the PIT phase inversion temperature determines the rate of phase inversion and whether the inversion phenomenon can be perceived at human skin temperature. An excessively high PIT temperature may indicate insufficient water evaporation, likely due to an increase in the content of hydrophilic emulsifiers. If the oil phase after phase inversion is too greasy and poorly absorbed, it may be due to an excess of squalane or other oils, or the addition of cetearyl stearyl alcohol to provide a solid framework, resulting in a more moisturizing feel. Unstable formulations may be due to an unreasonable combination of emulsion systems, failing to achieve synergistic effects, leading to unstable emulsion particles and particle size. The specific DSC test data results for the examples and comparative examples are shown in Table 1. The experimental results show that the overall PIT phase inversion data and absorption effect are highly consistent with the theoretical derivation of PIT phase inversion and test examples 1 and 2. This unexpectedly discovered excellent emulsifier combination has a specific application range, and the proportions and composition are equally important, closely related to actual skincare scenarios. This includes not only the skincare experience and application shear force, but also skin temperature and other factors specific to the application scenario.

[0161] According to the third section, the temperature is increased from 0°C to 90°C at a rate of 2–5°C / min. Taking Example 2 (PIT: 29°C) as an example, the phase inversion time is calculated to be 5.8 min at a heating rate of 5°C / min and 14.5 min at a heating rate of 2°C / min. Taking Example 9 (PIT: 27°C) as an example, the phase inversion time is calculated to be 5.4 min at a heating rate of 5°C / min and 13.5 min at a heating rate of 2°C / min. Taking Comparative Example 6 (PIT: 46°C) as an example, the phase inversion time is calculated to be 9.2 min at a heating rate of 5°C / min and 23 min at a heating rate of 2°C / min. Therefore, the phase inversion times of Examples 1-3, 5-14, 16, and 19-21 of this application are between 5.4 and 22.5 min, which are all superior to Comparative Example 6.

[0162] Table 1: Test data and effects of the compositions obtained in each embodiment

[0163] Application example:

[0164] The compositions prepared in Examples 1-21 can be used in the preparation of topical skin agents. The topical skin agent is preferably a cosmetic composition, such as a serum, lotion, cream, eye cream, or face mask. The weight percentage of the prepared composition sample in the topical skin agent is 10% to 100% (w / w). A preferred weight percentage is 50% to 100% (w / w). A more preferred weight percentage is 60% to 90% (w / w). The most preferred weight percentage is 60% to 80% (w / w).

[0165] The following are specific examples of the application of the prepared combinations in topical skin preparations, as well as the formulations and preparation methods of these dosage forms. In the tables below, "-" indicates no additives.

[0166] Application Example 1: Preparation of Face Cream

[0167] Application Example 2: Emulsion Preparation

[0168] Application Example 3: Preparation of Gel

[0169] Application Example 4: Preparation of Serum

[0170] Application Example 5: Preparation of Facial Masks

[0171] Application Example 6: Preparation of Eye Cream

Claims

1. An emulsion system composition having phase inversion properties, comprising: 15-20% by weight of oil phase; A 3-5% by weight ternary emulsifier system, wherein the ternary emulsifier system comprises a C12-20 alkyl glycoside nonionic emulsifier, a stabilizer, and a hydrophilic nonionic emulsifier with an HLB greater than 10; and Aqueous phase.

2. The emulsified system composition according to claim 1, characterized in that, The alkyl glycoside nonionic emulsifier is cetearyl glucoside.

3. The emulsified system composition according to claim 1, characterized in that, The stabilizer is glyceryl stearate.

4. The emulsified system composition according to claim 1, characterized in that, The hydrophilic nonionic emulsifier is a polyethylene glycol fatty acid ester nonionic emulsifier.

5. The emulsified system composition according to claim 1, characterized in that, The polyethylene glycol fatty acid ester nonionic emulsifier is PEG-100 stearate.

6. The emulsified system composition as described in claim 5, characterized in that, In the ternary emulsifier system, the weight ratio of C12-20 alkyl glycoside nonionic emulsifier: stabilizer: hydrophilic nonionic emulsifier is 1.8:1.3:0.

5.

7. The emulsified system composition according to claim 1, characterized in that, The phase transition temperature (PIT) of the emulsifier system is 27°C to 35°C, and the phase transition time is 5.4-22.5 min, preferably 5.4-17 min.

8. The emulsified system composition according to claim 1, characterized in that, When the composition is applied to the skin, under the combined effects of skin temperature, application shear force, and water evaporation, the system undergoes a controllable phase transition on the skin surface from an oil-in-water type to an oil-in-water type, and even an oil continuous phase.

9. A method for preparing an emulsion system composition as described in any one of claims 1-7, comprising: S1: Heat the aqueous phase to 75-80℃ to obtain solution 1; S2: Heat the ternary emulsifier system and the oil phase to 75-80℃ to obtain solution 2; S3: Add solution 2 to solution 1 and perform high-speed homogenization at a speed of 4000-5000 rpm for 8-15 min. S4: Defoaming and cooling yields a white cream.

10. A topical skin agent comprising the composition of any one of claims 1-8, wherein the topical skin agent is selected from the following forms: face cream, lotion, gel, serum, mask, eye cream.

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