Sunscreen synergistic emulsion composition based on micro-jet emulsification method and preparation process of sunscreen synergistic emulsion composition

Abstract

The invention relates to the technical field of cosmetics, in particular to a sunscreen synergistic emulsion composition based on a microjet emulsification method and a preparation process. The sunscreen synergistic emulsion composition is prepared from the following raw materials in percentage by weight: 0.5-5% of a fatty alcohol polyether type emulsifier; 0-5% of an anionic emulsifier; 0-5% of a nonionic emulsifier; 5-20% of a chemical sun-screening agent; 1 to 15% of polyol; 0.1 to 3% of aliphatic monohydric alcohol; 0.1-5% of a rheological additive; and the balance of solvent oil. According to the emulsifying composition, the specific fatty alcohol polyether type emulsifying agent, the anionic emulsifying agent and the nonionic emulsifying agent are selected to be compounded, an obtained emulsifying system can adapt to a micro-jet high-energy emulsifying treatment process, and uniform and fine emulsion with good stability is obtained; the invention further finds that the performance of the sunscreen synergistic composition can be improved to the greatest extent by performing micro-jet process treatment after emulsification and adding a thickening agent for post-thickening after emulsification.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of cosmetics, in particular to a sunscreen synergistic emulsified composition based on microfluidic emulsification method and a preparation process. BACKGROUND

[0002] As a key factor causing skin problems, ultraviolet (UV) can be divided into UV-A (320-400 nm), UV-B (280-320 nm) and UV-C (100-280 nm) according to the wavelength difference, and different wavelengths of ultraviolet cause different damages to the skin. Among them, UV-A can penetrate the skin surface and reach the dermis, thus easily causing skin aging, leading to a series of problems such as wrinkles and relaxation; UV-B mainly acts on the skin surface and is the culprit of sunburn, and long-term exposure to UV-B radiation can also significantly increase the incidence of skin cancer; UV-C is mainly used in the field of sterilization and disinfection, but due to the blocking effect of the ozone layer, it is not common in the natural environment. In daily protection, using sunscreen cosmetics is a common way for people to protect themselves from the sun. However, with the continuous deepening of skin science research, there have been reports that sunscreen agents have the risk of transdermal absorption, which may cause potential harm to the skin, which also makes sensitive skin groups have very limited choices for sunscreen cosmetics, and there are very few sunscreen cosmetics to choose from.

[0003] Under the condition of maintaining high sunscreen protection, reducing the use of sunscreen agents is one of the directions of the development of new sunscreen products. However, the sunscreen ability of sunscreen products is completely provided by organic and inorganic sunscreen agents in the system; in theory, reducing the use of sunscreen agents will usually result in the inability to maintain high sunscreen, making it impossible to balance the safety of sunscreen agents and high sunscreen protection.

[0004] As we all know, when sunscreen products are used, due to skin folds and facial structures, etc., the sunscreen products cannot be evenly spread on the skin under simple application; and the weak and hollow parts of these sunscreen layers will lead to insufficient local sunscreen, resulting in a decrease in the overall sunscreen value of the sunscreen product. Therefore, the spreading performance of the sunscreen product needs to be considered when designing the sunscreen product. There are many reasons that affect the spreading performance of the sunscreen product, such as increasing film-forming agents, thickeners, etc. which can improve the spreading performance of the sunscreen product to some extent, but the introduction of these raw materials will result in a heavy texture of the sunscreen product, and the consumer's use experience is not good, and the increased raw materials will also increase the cost.

[0005] Chinese invention patent CN117618315B discloses an emulsified composition with sunscreen function and its application. By using specific proportions and types of ingredients in water-in-oil sunscreen products, the problem of poor defense effect after water and sweat contact in the prior art is solved, the whitening, anti-allergic and moisturizing effects are realized, and a light, thin and breathable use feeling is provided, which is suitable for sensitive skin. Chinese invention patent application CN109498474A discloses a refreshing three-phase emulsified sunscreen cosmetic and its preparation method. By using the three-phase emulsified structure of water-in-oil-in-water and specific formula, the problem of stickiness of existing sunscreen cosmetics is solved, the combination of high efficiency sunscreen and refreshing feeling is realized, and the sunscreen effect and stability of the product are improved. However, the SPF of these products is still low, which cannot provide reliable ultraviolet protection effect.

[0006] In this background, it becomes a technical problem to be solved in the art to provide a sunscreen product with high sun protection factor, safety, mildness and good use experience. SUMMARY

[0007] To solve the above technical problems, the first aspect of the present application provides a sunscreen synergistic emulsified composition based on microfluidic emulsification method. The preparation raw materials of the sunscreen synergistic emulsified composition include, in terms of weight percentage: fatty alcohol polyether type emulsifier 0.5-5% anionic emulsifier 0-5%; non-ionic emulsifier 0-5%; chemical sunscreen agent 5-20%; polyol 1-15%; aliphatic monohydric alcohol 0.1-3%; rheological aid 0.1-5%; solvent oil to make up the balance; The mass ratio of the anionic emulsifier and the non-ionic emulsifier is 1: (1.5-3).

[0008] The fatty alcohol polyether type emulsifier can include behenyl alcohol polyether-25, behenyl alcohol polyether-20, stearyl alcohol polyether-25, stearyl alcohol polyether-20, stearyl alcohol polyether-15, stearyl alcohol polyether-10, cetyl alcohol polyether-25, cetyl alcohol polyether-20, cetyl alcohol polyether-15, cetyl stearyl alcohol polyether-20, stearyl alcohol polyether-2, lauryl alcohol polyether-4, lauryl alcohol polyether-7, lauryl alcohol polyether-10, PEG-100 stearate, etc.

[0009] Optionally, the fatty alcohol polyether type emulsifier includes a combination of one or more of behenyl alcohol polyether-25, stearyl alcohol polyether-20, behenyl alcohol polyether-20, cetyl alcohol polyether-20, cetyl stearyl alcohol polyether-20, and stearyl alcohol polyether-2.

[0010] Further optionally, the fatty alcohol polyether type emulsifier includes behenyl alcohol polyether-25 and stearyl alcohol polyether-20, wherein the mass ratio of behenyl alcohol polyether-25 to stearyl alcohol polyether-20 is (2-3):(2-3); most preferably 3:2.

[0011] In some embodiments, the amount of the anionic emulsifier added is 0.5-2%.

[0012] Optionally, the anionic emulsifier includes at least one of cetyl phosphate salts (such as potassium cetyl phosphate) and stearoyl glutamate salts (such as sodium stearoyl glutamate).

[0013] In some embodiments, the amount of the nonionic emulsifier added is 1-3%.

[0014] The nonionic emulsifier includes one or more combinations of glyceryl stearate, glyceryl stearate SE (a mixture of monoglyceride and a small amount of stearate), glycolipid, cetearyl alcohol, cetearyl glucoside, and arachidonic acid glucoside.

[0015] Further optionally, the anionic emulsifier includes potassium cetyl phosphate; the nonionic emulsifier includes glyceryl stearate.

[0016] Optionally, the mass ratio of the anionic emulsifier to the nonionic emulsifier is 1:(1.5-3).

[0017] The emulsifying composition of the present invention is a compound of specific fatty alcohol polyether emulsifiers (behenyl alcohol polyether-25 and stearyl alcohol polyether-20), anionic emulsifiers (potassium cetyl phosphate), and nonionic emulsifiers (glyceryl stearate). The hydrophilic and lipophilic structures of behenyl alcohol polyether-25 and stearyl alcohol polyether-20 form a stable adsorption layer at the oil-water interface. The addition of potassium cetyl phosphate and glyceryl stearate effectively prevents the aggregation and coalescence of emulsion droplets, further enhancing the robustness of the emulsion system. The resulting emulsion system can adapt to microfluidic high-energy emulsification processes, resulting in a stable, uniform, and delicate emulsion.

[0018] The chemical sunscreen agents mentioned may include 3-benzyl camphor, 4-methylbenzyl camphor, benzophenone-3, benzophenone-4, benzophenone-5, benzyl camphor sulfonic acid and its salts, bis-ethylhexyloxyphenol methoxyphenyl triazine, butyl methoxydibenzoylmethane, camphor benzalkonium methyl sulfate, diethylaminohydroxybenzoyl benzoate, diethylhexylbutamidotriazine, disodium phenyl dibenzimidazole tetrasulfonate, cresoltrazolium trisiloxane, and dimethyl PA BA ethylhexyl ester, ethylhexyl methoxycinnamate, ethylhexyl salicylate, octocrylene, ethylhexyl triazine ketone, homosalyl ester, isoamyl p-methoxycinnamate, methylene bis-benzotriazolyl tetramethylbutylphenol, PEG-25 p-aminobenzoic acid, phenylbenzimidazole sulfonic acid or its salts (e.g., potassium salt, sodium salt or triethanolamine salt), polyacrylamide methylbenzyl camphor, polysiloxane-15, terephthalic dicamphor sulfonic acid or its salts.

[0019] Optionally, the chemical sunscreen agent includes chemical sunscreen agent one and chemical sunscreen agent two; the mass ratio of chemical sunscreen agent one to chemical sunscreen agent two is (10-20):(1-5); further optionally, it is (12-15):2.4.

[0020] Optionally, the first chemical sunscreen agent comprises one or more of the following: diethylhexylbutamidotriazinone, bis-ethylhexyloxyphenol methoxyphenyl triazine, ethylhexyl triazinone, ethylhexyl salicylate, octocrylene, butyl methoxydibenzoylmethane, terephthalimide dicamphor sulfonic acid, humosasulfate, phenylbenzimidazole sulfonic acid, diethylaminohydroxybenzoylhexyl benzoate, or polysiloxane-15; further optionally, the first chemical sunscreen agent comprises bis-ethylhexyloxyphenol methoxyphenyl triazine, diethylaminohydroxybenzoylhexyl benzoate, ethylhexyl salicylate, humosasulfate, polysiloxane-15, and ethylhexyl triazinone in a mass ratio of (1-3):(1.5-5):(2-4):(2-4):(1-3):(2-5); most preferably, it is 1.5:2.5:3:3:2:3.

[0021] Optionally, the chemical sunscreen agent includes phenylbenzimidazole sulfonic acid.

[0022] The preferred chemical sunscreen agent of this invention comprises bis-ethylhexyloxyphenol methoxyphenyl triazine, diethylamino hydroxybenzoyl hexyl benzoate, ethylhexyl salicylate, homosalate, polysiloxane-15, and ethylhexyl triazine ketone in a mass ratio of (1-3):(1.5-5):(2-4):(2-4):(1-3):(2-5), and the second chemical sunscreen agent comprises phenylbenzimidazole sulfonic acid. The resulting sunscreen synergistic composition has high protective ability, passes skin patch test, has no adverse skin reaction, is mild and non-irritating, and has strong safety.

[0023] Optionally, the polyol includes one or more combinations of butanediol, 1,2-pentanediol, glycerol, dipropylene glycol, and sorbitol; further optionally, it is butanediol, 1,2-pentanediol, and glycerol in a mass ratio of (15-30):(1-4):(2-8); most preferably, it is 10:2:5.

[0024] Optionally, the aliphatic monohydric alcohol includes one or more combinations of stearyl alcohol, behenyl alcohol, and cetearyl alcohol; further, it may be cetearyl alcohol.

[0025] Optionally, the rheology modifier includes cellulose or a derivative thereof.

[0026] Cellulose derivatives may include xanthan gum, sodium carboxymethyl cellulose, hydroxyethyl cellulose, microcrystalline cellulose, etc.; xanthan gum may be selected in this invention.

[0027] Optionally, the solvent oil includes one or more of the following: diisopropyl sebacate, C12-15 alcohol benzoate, phenylethyl benzoate, ethylhexyl salicylate, butyl octyl salicylate, dibutyl adipate, phenylethyl benzoate, macadamia nut (MACADAMIA TERNIFOLIA) seed oil, jojoba oil, and isoalkanes (such as isodecane, isodecadecane, isodexadecane, isohexadecane, squalane, etc.).

[0028] Further optionally, the solvent oil comprises diisopropyl sebacate and C12-15 benzoyl sebacate, wherein the mass ratio of diisopropyl sebacate to C12-15 benzoyl sebacate is 1:(0.5-3); most preferably, it is 1:1.

[0029] In some embodiments, the raw materials for preparing the sunscreen-enhancing emulsified composition are mixed in a manner that separates them into the following phases according to their hydrophilic and lipophilic properties: Phase A (Oil Phase): Chemical sunscreen agents, solvent oils, fatty alcohol polyether emulsifiers, anionic emulsifiers, nonionic emulsifiers, and aliphatic monohydric alcohols; Phase B (aqueous phase): polyols, chemical sunscreens, and rheology modifiers.

[0030] In some embodiments, the sunscreen-enhancing emulsified composition may also contain other ingredients permitted in cosmetic product formulations, such as skin conditioners, emollients, pH adjusters, thickeners, and preservatives.

[0031] The skin conditioning agents mentioned may include panthenol, allantoin, etc.

[0032] Examples of such softeners include cyclopentadimethylsiloxane and isohexadecane.

[0033] The pH adjuster may include aminomethylpropanol, citric acid, malic acid, etc.

[0034] The thickener may include, for example, hydroxyethyl acrylate / sodium acryloyldimethyl taurate copolymer.

[0035] Optionally, the sunscreen-enhancing emulsified composition further includes 0.1-3% of a skin conditioning agent, wherein the skin conditioning agent comprises panthenol and allantoin, wherein the mass ratio of panthenol to allantoin is 1:1; wherein the panthenol and allantoin are added in phase B.

[0036] Optionally, the sunscreen-enhancing emulsified composition further includes a softener comprising cyclopentamethoxysiloxane, which is added in phase B.

[0037] Optionally, the sunscreen-enhancing emulsified composition further includes a pH adjuster of 0.1-10%, wherein the pH adjuster includes aminomethylpropanol, which is added in phase B.

[0038] Optionally, the raw materials for preparing phase B are further divided into the following phases based on their solubility and then mixed: Phase B1 (dissolves at 70-80℃): polyols, rheology modifiers, skin conditioning agents; Phase B2 (dissolves at room temperature): softener; Phase B3 (dissolves at room temperature): Chemical sunscreen agent II, pH adjuster.

[0039] In some embodiments, a preservative, such as p-hydroxyacetophenone, may also be added to the B1 phase.

[0040] The second aspect of the present invention provides a preparation process for a sunscreen-enhancing emulsified composition based on microfluidic emulsification; the preparation process includes: mixing the raw materials for preparing the emulsified composition according to their hydrophilic and lipophilic properties to obtain an aqueous phase mixture and an oil phase mixture; mixing the pre-dissolved and uniformly dissolved oil phase mixture and aqueous phase mixture, homogenizing them to obtain material one; and subjecting material one to microfluidic treatment to obtain the finished product.

[0041] Optionally, the preparation process includes: S1. Mix chemical sunscreen agent 1, solvent oil, fatty alcohol polyether type emulsifier, anionic emulsifier, nonionic emulsifier and aliphatic monohydric alcohol, heat to 75-85℃, dissolve and mix evenly to obtain oil phase mixture; S2. Mix the polyol, chemical sunscreen agent II, and rheology modifier, and dissolve and mix them evenly to obtain an aqueous mixture; S3. Mix the oil phase mixture and the water phase mixture, homogenize, and obtain material one; S4. Perform micro-jet processing on material 1.

[0042] Optionally, the microjets are subjected to microjets 2-4 times at 500-2000 bar.

[0043] In some embodiments, the sunscreen-enhancing emulsifying composition further includes 0.1-1% of a C phase, which is a thickener, specifically a mixture of hydroxyethyl acrylate / sodium acryloyl dimethyl taurate copolymer, water, isohexadecane, polysorbate-60, and sorbitan isostearate.

[0044] In some embodiments, the sunscreen-enhancing emulsified composition further includes 0.2-1% of phase D, which is a preservative, specifically a mixture of caprylyl glycol and ethylhexylglycerin.

[0045] The preparation process further includes S5: cooling the micro-jet treated material one to 40-50℃ to obtain material two; adding pre-dispersed thickener and preservative to material two, homogenizing for 3-10 minutes to obtain the finished product.

[0046] Optionally, the preparation process includes: S1. Mix the raw materials for the preparation of phase A, heat to 75-85℃, dissolve and mix evenly to obtain an oil phase mixture; S2. Mix the raw materials for preparing phase B1 and dissolve and mix them evenly at 70-80℃; stir the raw materials for preparing phases B2 and B3 evenly at room temperature to obtain a mixture of three aqueous phases; S3. Add phases A, B2, and B3 into phase B1 respectively, homogenize for 1-10 minutes, and obtain material one; S4. Transfer the material to the microjet device and perform microjet treatment 2-4 times at 500-2000 bar. S5. Cool the micro-jet treated material one to 40-50℃ to obtain material two; add pre-dispersed thickener and preservative to material two, homogenize for 3-10 minutes to obtain the finished product.

[0047] In some embodiments, the C-phase thickener is added first and homogenized for 1-5 minutes. After confirming the thickening state, the D-phase preservative is added, homogenized for 3-10 minutes, and then cooled to room temperature to remove bubbles, thus obtaining the finished product.

[0048] This invention optimizes both the formulation and the preparation process, particularly exploring the timing of microfluidic treatment. It was found that performing microfluidic treatment after emulsification, followed by the addition of a thickener for post-thickening, maximizes the performance of the sunscreen-enhancing composition. The emulsion treated with microfluidic technology exhibits significantly improved stability due to the substantial reduction in particle size and uniform distribution. Based on the interaction between high pressure and high-speed fluids, the sunscreen-enhancing composition is pulverized into smaller particles, weakening the interaction forces between droplets. This results in a stable, homogeneous, and fine liquid. The uniform dispersion also enhances the skin feel of the product, making the cosmetic smoother and more comfortable to use, and allowing the active ingredients to function more effectively. The SPF of the sunscreen-enhancing composition is increased to over 50, and the product maintains a high level of sun protection even with reduced sunscreen dosage.

[0049] Many factors influence particle size in the cosmetics industry. Considering factors such as cost, environmental protection, safety, and product characteristics, this invention preferably combines emulsification processes with specific emulsification systems to effectively reduce emulsion particle size, improve product spreadability, and thus enhance sun protection capabilities. This invention focuses on optimizing the emulsification process—microfluidic emulsification (MF)—and the types of emulsifiers suitable for microfluidic methods. During the research, it was found that not all emulsifiers are suitable for the high-energy emulsification method of microfluidics. Ultimately, specific emulsifiers were selected to work with the microfluidic process, effectively reducing the particle size of sunscreen products. Furthermore, the sunscreen products pass human SPF testing. This microfluidic technology provides a completely new approach to sunscreen product development.

[0050] In some embodiments, the dosage form of the sunscreen-enhancing emulsified composition is at least one of lotion, cream, or lotion.

[0051] Beneficial effects: This invention provides a sunscreen-enhancing emulsified composition and its preparation process based on microfluidic emulsification, which has the following advantages: (1) The emulsifying composition of the present invention is formulated by combining specific fatty alcohol polyether emulsifiers (behenyl alcohol polyether-25 and stearyl alcohol polyether-20), anionic emulsifiers (potassium cetyl phosphate) and nonionic emulsifiers (glyceryl stearate). The resulting emulsifying system can adapt to the microfluidic high-energy emulsification process and obtain a stable, uniform and delicate emulsion. The composition of the present invention has a small particle size and good spreadability of the product.

[0052] (2) The preferred chemical sunscreen agent of the present invention includes bis-ethylhexyloxyphenol methoxyphenyl triazine, diethylamino hydroxybenzoyl hexyl benzoate, ethylhexyl salicylate, humosasulfate, polysiloxane-15 and ethylhexyl triazine ketone in a mass ratio of (1-3):(1.5-5):(2-4):(2-4):(1-3):(2-5), and the second chemical sunscreen agent includes phenylbenzimidazole sulfonic acid. The resulting sunscreen synergistic composition has high protective ability, can pass the skin patch test, has no adverse skin reaction, is mild and non-irritating, and has strong safety.

[0053] (3) The emulsification composition of the present invention further selects xanthan gum as a rheology modifier and diisopropyl sebacate and C12-15 benzoyl alcohol as solvent oils, which can improve the compatibility of the composition, give full play to the protective effect, and increase the SPF of the obtained sun protection enhanced composition to more than 50.

[0054] (4) The sun protection synergistic emulsified composition provided by the present invention has good spreadability and can reduce the amount of sunscreen agent while maintaining high sun protection power, providing a new idea for the development of sun protection products.

[0055] (5) This invention optimizes the preparation process while optimizing the composition formulation, especially the timing of microjets. It was found that microjets are applied after emulsification, followed by thickening with a thickener, which can maximize the performance of the sunscreen composition. Attached Figure Description

[0056] Figure 1 Particle size analysis results of the control group and samples from experiments 1-4; Figure 2 Photographs of the finished products of Examples 1-2 and Comparative Examples 1-3; from left to right: Comparative Example 1, Comparative Example 2, Comparative Example 3, Example 1, and Example 2; Figure 3 SPF test results of Examples 1, 2 and 3. Detailed Implementation

[0057] Note: Unless otherwise specified, all concentrations mentioned in this invention are mass concentrations; the room temperature is 25°C; and all raw materials and consumables used are commercially available.

[0058] Examples and Comparative Examples Examples 1-2 and Comparative Example 1 provide a sunscreen-enhancing emulsion composition (dosage form: cream) based on microfluidic emulsification, the formulation of which is shown in Table 1 below; the values ​​in Table 1 represent the mass percentage of the raw materials in the sunscreen-enhancing emulsion composition.

[0059] Table 1

[0060] The following is some information about the raw materials in Table 1.

[0061] Polysiloxane-15: sourced from DSM-Firmenich.

[0062] Behenyl alcohol polyether-25: sourced from BASF.

[0063] Stearyl alcohol polyether-20: sourced from BASF.

[0064] C12-15 alcohol benzoate: CAS number 68411-27-8, sourced from Innospec Ltd.

[0065] Cyclopentadimethylsiloxane: derived from KCC SILICONE (Korea).

[0066] The pH adjuster is a mixture of water and aminomethylpropanol, wherein the mass ratio of water to aminomethylpropanol is 5:95.

[0067] The thickener is a mixture of hydroxyethyl acrylate / sodium acryloyl dimethyl taurate copolymer, water, isohexadecane, polysorbate-60, and sorbitan isostearate; the mixture is sourced from SEPPIC.

[0068] Preservative 2 is a mixture of caprylyl glycol and ethylhexylglycerin, wherein the mass ratio of caprylyl glycol to ethylhexylglycerin is 4:1.

[0069] The preparation process of the sunscreen-enhancing emulsified composition in Example 1 includes: S1. Oil phase dispersion: Mix the raw materials for the preparation of phase A, heat to 77.5±2.5℃, dissolve and mix evenly to obtain an oil phase mixture; S2. Aqueous phase dispersion: Mix phase B1 and dissolve and mix evenly at 75°C; stir the raw materials for preparing phases B2 and B3 evenly at room temperature to obtain three aqueous phase mixtures; S3. Emulsification: Phase A, Phase B2, and Phase B3 are respectively added to Phase B1 and homogenized for 5 minutes to obtain material one; S4. Microjet: Transfer material 1 to a microjet device and perform microjet treatment twice at 1000 bar. S5. Post-processing: Cool the micro-jet treated material one to 45°C to obtain material two; add the pre-dispersed C-phase thickener to material two and homogenize for 3 minutes. After confirming the thickening state, add D-phase preservative two, homogenize for 5 minutes, cool to room temperature to degas, and obtain the finished product.

[0070] The design concept of the above preparation process is as follows: the oil phase and the aqueous phase are dispersed (corresponding to steps S1 and S2), emulsified (corresponding to step S3), microfluidized (corresponding to step S4), and post-treated (corresponding to step S5) to obtain the final sunscreen-enhancing emulsified composition.

[0071] Before determining the above preparation process, the present invention conducted a process comparison experiment based on the formulation of Example 1. The scheme of the process comparison experiment is shown in Table 2 below.

[0072] Table 2

[0073] The processing conditions for some steps in Table 2 are as follows: The pre-microfluidic treatment conditions were: two microfluidic passes at 1000 bar.

[0074] Pre-thickening: In step S2, C-phase thickener is added for pre-thickening.

[0075] The conditions for microfluidic treatment after emulsification were: two microfluidic passes at 1000 bar.

[0076] Post-thickening: In step S5, a C-phase thickener is added for post-thickening.

[0077] The preparation process of the control group sample was the same as that in Example 1; the difference was that: ① the material was not subjected to microfluidic treatment; ② the C phase thickener was added in step S2 (pre-thickening).

[0078] The preparation process of the sample in Experiment 1 was the same as in Example 1; the difference was that the oil phase mixture was subjected to 1000 bar microjets twice, while material 1 was not subjected to microjets; that is, the preparation steps of the sample in Experiment 1 were as follows: S1. Oil phase dispersion: Mix the raw materials for the preparation of phase A, heat to 77.5±2.5℃, dissolve and mix evenly to obtain an oil phase mixture; transfer the oil phase mixture to a microjet device and perform microjet treatment twice at 1000 bar.

[0079] S2. Aqueous phase dispersion: The raw materials for preparing phase B1 are mixed and dissolved at 75°C until homogeneous; the raw materials for preparing phases B2, B3, and C are stirred separately at room temperature until homogeneous to obtain four aqueous phase mixtures; S3. Emulsification: The microfluidized phases A, B2, B3, and C are respectively added to phase B1 and homogenized for 5 minutes to obtain material one; S4. Post-processing: Cool material one to 45°C to obtain material two; add pre-dispersed D-phase preservative two to material two, homogenize for 5 minutes, cool to room temperature to degas, and obtain the finished product.

[0080] The preparation process of the sample in Experiment 2 was the same as that in Example 1; the differences were: ① the aqueous phase mixture was subjected to 1000 bar microjets twice, but material 1 was not subjected to microjets; ② the C-phase thickener was added in step S2 (pre-thickening); that is, the preparation steps of the sample in Experiment 2 are as follows: S1. Oil phase dispersion: Mix the raw materials for the preparation of phase A, heat to 77.5±2.5℃, dissolve and mix evenly to obtain an oil phase mixture; S2. Aqueous phase dispersion: The raw materials for the preparation of phase B1 are mixed and dissolved and mixed evenly at 75°C; the raw materials for the preparation of phases B2, B3, and C are stirred evenly at room temperature to obtain four aqueous phase mixtures; the four aqueous phase mixtures are transferred to a microfluidic device and subjected to microfluidic treatment twice at 1000 bar.

[0081] S3. Emulsification: Phases A, B2, B3, and C are respectively added to phase B1 (phases B1, B2, B3, and C have all been treated with microfluidics), homogenized for 5 minutes, and material one is obtained; S4. Post-processing: Cool material one to 45°C to obtain material two; add pre-dispersed D-phase preservative two to material two, homogenize for 5 minutes to obtain the finished product.

[0082] In Experiment 3, after the emulsified material was treated with the microfluidic process, a C-phase thickener was added for post-thickening, i.e., the sample preparation process was the same as in Example 1.

[0083] The preparation process of the sample in Experiment 4 was the same as that in Example 1; the difference was that the raw materials for preparing the sunscreen-enhancing emulsified composition did not contain C-phase thickener (no pre-thickening or post-thickening treatment was performed), and the difference was made up with water.

[0084] Example 2 A sunscreen-enhancing emulsified composition, the formulation of which is shown in Table 1, and the preparation process is the same as in Example 1.

[0085] Compare with Example 1 The formulation is shown in Table 1, and the preparation process is a conventional emulsification method; the specific preparation steps include: (1) Heat and dissolve phase A and phase B raw materials respectively, so that phase A and phase B raw materials are completely dissolved and dispersed at a temperature of 75°C to obtain an oil phase mixture and an aqueous phase mixture; (2) Add the oil phase mixture and the pre-dispersed B2 phase into the water phase mixture, and use a homogenizer to pre-homogenize to emulsify; add the pre-mixed room temperature phase (C phase, D phase), continue homogenizing until the material texture is uniform, cool down to 25℃ to defoam, and obtain the finished product.

[0086] Compare with Example 2 The formulation is the same as that of Control Example 1, and the preparation process is the same as that of Example 1 (microfluidic treatment method).

[0087] Compare with Example 3 The formulation is the same as in Example 1, and the preparation process is the same as in Control Example 1 (conventional emulsification method).

[0088] Comparative Examples 1-6 The specific implementation method is the same as in Example 1; the difference lies in the selection of the fatty alcohol polyether, as shown in Table 3; in Comparative Example 1, the amount of fatty alcohol polyether added is 2.8 wt% (behenyl alcohol polyether-25 2 wt%, stearyl alcohol polyether-20 0.8 wt%), in Comparative Example 2, the amount of fatty alcohol polyether added is 4.5 wt% (behenyl alcohol polyether-25 1.5 wt%, stearyl alcohol polyether-20 3 wt%), and in Comparative Examples 3 to 6, the amount of fatty alcohol polyether added is 2 wt%.

[0089] Table 3

[0090] Performance testing Particle size analysis was performed on the control group and samples from experiments 1-4 using a DLS dynamic light scattering instrument. The results are shown in [Figure number missing]. Figure 1 .

[0091] from Figure 1 It can be seen that when the aqueous and oil phase materials are dispersed separately, then emulsified and subjected to microfluidic treatment, the resulting composition has the smallest average particle size and uniform particle size. Comparison of Experiments 3 and 4 shows that post-thickening has little effect on particle size.

[0092] 2. Emulsification effect Photographs of the finished products of Examples 1-2 and Comparative Examples 1-3 are shown below. Figure 2 (From left to right: Comparative Example 1, Comparative Example 2, Comparative Example 3, Example 1, and Example 2).

[0093] Comparing the results of Comparative Example 1 and Comparative Example 2, it can be seen that the material obtained by conventional emulsification (Comparative Example 1) is milky white and has normal properties, while the material treated by microfluidics (Comparative Example 2) has a pale yellow bottom and significantly reduced stability, with oil-type demulsification. This may be because the emulsification system cannot adapt to high-energy emulsification processes like microfluidics, resulting in poor emulsification effect. This demonstrates that not all emulsifiers are suitable for processing using microfluidics.

[0094] Further comparing Example 1 with Comparative Examples 2 and 3, Example 1 used the preferred emulsifying composition of the present invention combined with microfluidic emulsification treatment, resulting in a stable product with uniform and fine emulsion particles. Comparative Example 3 had the same formulation as Example 1, but the sample was prepared using a conventional emulsification method. The final sample exhibited a milky white layer at the bottom. This phenomenon can be attributed to Auschwitz curing; due to the uneven size of the emulsion particles, smaller particles merged with larger particles, ultimately causing the emulsion particles to float to the top, resulting in water seepage from the bottom and decreased stability.

[0095] 3. Skin reaction test Example 1 and Control Example 3 were used as test samples, and 30 Asian adult subjects aged 18-46 years were selected for randomized skin patch testing. The specific test method was as follows: 0.020g-0.025g of sample (Example 1, Control Example 3) was placed in a patch applicator. The patch applicator containing the test sample was applied to the flexor side of the subject's forearm with non-irritating adhesive tape, and the palm was gently pressed to ensure even adhesion to the skin for 24 hours. Referring to the Cosmetic Safety Technical Specifications (2015 edition), skin reactions were observed according to the skin adverse reaction grading standards at 30 minutes (after the indentation disappeared), 24 hours, and 48 hours after removing the patch applicator to determine whether the product had any adverse reactions on human skin. Each subject used both Example 1 and Control Example 3 samples simultaneously for testing. During testing, all samples were applied to the same arm and the same area, and the patch applicator served as a constraint, preventing mutual interference. The result grading is shown in Table 4 below.

[0096] Table 4

[0097] Test results showed that, 30 min, 24 h and 48 h after removing the test sample applicator, none of the 30 subjects experienced adverse skin reactions in the two products of Example 1 and Control Example 3. This demonstrates that the two test samples did not cause adverse reactions in humans, indicating that microfluidic treatment does not increase the irritation risk of the sunscreen-enhancing emulsion composition.

[0098] 4. Sun Protection Factor (SPF) Test SPF tests were performed on Examples 1, 2, and 3 (Control Example 3). The specific test method was as follows: Three subjects were selected and placed in a prone position for ultraviolet (UV) irradiation of their backs. The minimum erythema dose (MED) of the subjects' skin to UV irradiation was predicted 24 hours prior to the experiment, and the UV irradiation dose was adjusted accordingly for the test sample. On the day of the experiment, a normal skin area of ​​at least 30 cm² was selected on the subject's back. The test sample or standard control sample was evenly applied to this area at a dosage of (2.00 ± 0.05) mg / cm². After waiting 15 minutes, an appropriate UV irradiation dose was selected, and irradiation was performed under three conditions: ① no sample was applied to the subject's skin; ② standard control sample (P2, SPF=16.1) was applied; ③ test sample was applied. The experimental results were observed 16-24 hours later, and the MED values ​​of each sample under each condition were recorded. Each subject was tested under Example 1, Example 2, and Control Example 3; the average value of the test results was taken.

[0099] SPF can be calculated as the ratio of the MED required to cause erythema on skin protected by sunscreen to the MED required to cause erythema on unprotected skin, using the following formula:

[0100] The SPF test results for Examples 1, 2, and 3 are shown below. Figure 3 Comparing the results of Comparative Example 3 and Example 1, it can be seen that using the microfluidic technology of the present invention can increase the SPF of the composition by 22% under the same formulation. Comparing the results of Comparative Example 3 and Example 2, it can be seen that even with a 20% reduction in the amount of sunscreen agent, the microfluidic technology of the present invention can effectively improve the sun protection effect of the composition, and the SPF of Example 2 is still higher than that of Comparative Example 3. Therefore, using the specific emulsified composition formulation and microfluidic process of the present invention in combination can achieve excellent sun protection enhancement effects, while reducing the amount of sunscreen agent used while ensuring sun protection effectiveness, making it highly practical.

Claims

1. A sunscreen-enhancing emulsified composition based on microfluidic emulsification, characterized in that, The raw materials for preparing the sunscreen-enhancing emulsified composition, by weight percentage, include: Fatty alcohol polyether type emulsifier 0.5-5%; Anionic emulsifier 0-5%; Nonionic emulsifier 0-5%; Chemical sunscreens: 5-20%; Polyols 1-15%; Aliphatic monohydric alcohols 0.1-3%; Rheology modifier 0.1-5%; Replenish solvent oil to the remaining amount; The mass ratio of the anionic emulsifier to the nonionic emulsifier is 1:(1.5-3).

2. The sunscreen-enhancing emulsified composition based on microfluidic emulsification according to claim 1, characterized in that, The fatty alcohol polyether type emulsifier includes one or more combinations of behenyl alcohol polyether-25, stearyl alcohol polyether-20, behenyl alcohol polyether-20, cetyl alcohol polyether-20, cetearyl alcohol polyether-20, and stearyl alcohol polyether-2.

3. The sunscreen-enhancing emulsified composition based on microfluidic emulsification according to claim 1, characterized in that, The anionic emulsifier includes at least one of cetyl phosphate and stearoyl glutamate. The nonionic emulsifier includes one or more combinations of glyceryl stearate, glyceryl stearate SE, glycolipid, cetearyl alcohol, cetearyl glucoside, and arachidonic acid glucoside.

4. The sunscreen-enhancing emulsified composition based on microfluidic emulsification according to claim 1, characterized in that, The chemical sunscreen agent includes chemical sunscreen agent one and chemical sunscreen agent two; the mass ratio of chemical sunscreen agent one to chemical sunscreen agent two is (10-20):(1-5); The chemical sunscreen agent includes bis-ethylhexyloxyphenol methoxyphenyl triazine, diethylaminohydroxybenzoylhexyl benzoate, ethylhexyl salicylate, homosalate, polysiloxane-15 and ethylhexyl triazine ketone, in a mass ratio of (1-3):(1.5-5):(2-4):(2-4):(1-3):(2-5); The chemical sunscreen agent 2 includes phenylbenzimidazole sulfonic acid.

5. The sunscreen-enhancing emulsified composition based on microfluidic emulsification according to claim 4, characterized in that, The polyols include one or more combinations of butanediol, 1,2-pentanediol, glycerol, dipropylene glycol, and sorbitol.

6. The sunscreen-enhancing emulsified composition based on microfluidic emulsification according to claim 4, characterized in that, The aliphatic monohydric alcohols include one or more combinations of stearyl alcohol, behenyl alcohol, and cetearyl alcohol.

7. The sunscreen-enhancing emulsified composition based on microfluidic emulsification according to claim 4, characterized in that, The solvent oil includes one or more of the following: diisopropyl sebacate, C12-15 alcohol benzoate, phenylethyl benzoate, ethylhexyl salicylate, butyl octyl salicylate, dibutyl adipate, phenylethyl benzoate, macadamia seed oil, jojoba oil, and isoparaffins.

8. A preparation process for a sunscreen-enhancing emulsified composition based on microfluidic emulsification according to any one of claims 4-7, characterized in that, The preparation process includes: S1. Mix chemical sunscreen agent 1, solvent oil, fatty alcohol polyether type emulsifier, anionic emulsifier, nonionic emulsifier and aliphatic monohydric alcohol, heat to 75-85℃, dissolve and mix evenly to obtain oil phase mixture; S2. Mix the polyol, chemical sunscreen agent II, and rheology modifier, and dissolve and mix them evenly to obtain an aqueous mixture; S3. Mix the oil phase mixture and the water phase mixture, homogenize, and obtain material one; S4. Perform micro-jet processing on material 1.

9. The preparation process of the sunscreen-enhancing emulsified composition based on microfluidic emulsification according to claim 8, characterized in that, The conditions for the microjets were: 2-4 microjets were treated at 500-2000 bar.

10. The preparation process of the sunscreen-enhancing emulsified composition based on microfluidic emulsification according to claim 9, characterized in that, The raw materials for preparing the sunscreen-enhancing emulsified composition also include thickeners and preservatives; The preparation process further includes S5: cooling the micro-jet treated material one to 40-50℃ to obtain material two; adding pre-dispersed thickener and preservative to material two, homogenizing for 3-10 minutes to obtain the finished product.

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