A solution of botryococcus braunii gel-cholesterol-phospholipid liposome and a preparation method thereof

Abstract

This application relates to the technical field of cosmetics, specifically disclosing an alginate-cholesterol-phospholipid biomimetic liposome solution and its preparation method. The preparation method of the alginate-cholesterol-phospholipid biomimetic liposome solution includes the following steps: preparation of the alginate-phospholipid mixture: alginate and phospholipid are mixed in water, controlling the phospholipid concentration in the system to be 1.0-9.0 wt%, and stirred and mixed evenly under specific temperature conditions; encapsulation of sunscreen: a chemical sunscreen agent and cholesterol are dissolved in oil to obtain a sunscreen agent solution; the sunscreen agent solution is added to the alginate-phospholipid mixture, controlling the sunscreen agent concentration in the system to be 0.9-7.1 wt%, first homogenized at high speed, and then slowly stirred and cooled under controlled conditions to obtain the final product. This alginate-cholesterol-phospholipid biomimetic liposome solution, which encapsulates sunscreen agents with alginate, cholesterol, and phospholipids, can be used to prepare sunscreen cosmetics, and has the advantages of low irritation and good sunscreen stability.

Description

Technical Field

[0001] This application relates to the technical field of cosmetics, and more specifically, to a biomimetic liposome solution of alginate-cholesterol-phospholipid and its preparation method. Background Technology

[0002] As our understanding of the impact of ultraviolet radiation on skin photoaging, pigmentation, and the risk of skin cancer deepens, sun protection has become an indispensable part of daily skin care. Sunscreen products on the market mainly rely on chemical and physical sunscreens, or a combination of both, to achieve broad-spectrum sun protection.

[0003] Physical sunscreens are limited in application due to their heavy feel and tendency to leave a white cast. While mainstream small-molecule chemical sunscreens, such as octocrylene and avobenzone, offer high sun protection, they have significant drawbacks: firstly, their photostability is poor, making them prone to photodegradation under prolonged UV exposure, leading to decreased sun protection performance; secondly, some chemical sunscreens have small molecular weights, allowing for transdermal penetration, and they themselves or their photodegradation products may cause significant skin irritation, potentially leading to skin sensitivity with long-term use. Summary of the Invention

[0004] In order to improve the stability of chemical sunscreens while reducing irritation, this application provides an alginate-cholesterol-phospholipid biomimetic liposome and its preparation method.

[0005] In a first aspect, this application provides a method for preparing alginate-cholesterol-phospholipid biomimetic liposomes, employing the following technical solution: A method for preparing an alginate-cholesterol-phospholipid biomimetic liposome solution includes the following steps: a. Preparation of the alginate-phospholipid mixture: Mix alginate and phospholipids in water, controlling the phospholipid concentration in the system to be 1.0-9.0 wt%. Mix well under stirring conditions of 55-60℃ and 30-60 rpm for 5-20 minutes to obtain the final product. b. Encapsulation of sunscreen agents: Chemical sunscreen agents and cholesterol are dissolved in oil, heated to 70-80℃ and stirred until well mixed to obtain a sunscreen solution; Add the sunscreen solution to the alginate-phospholipid mixture, controlling the concentration of the sunscreen in the system to be 0.9-7.1 wt%. First, homogenize at high speed for 3-5 minutes at 500-3500 rpm. Then, slowly stir and cool at 45-65℃ and 20-500 rpm until the alginate-cholesterol-phospholipid mixture self-assembles to form liposomes that fully encapsulate the chemical sunscreen.

[0006] By employing the above-mentioned technical solution, algae extract and phospholipids are mixed in a certain proportion. Then, the dissolved chemical sunscreen agent and cholesterol are slowly added to the algae extract-phospholipid mixture. Under specific conditions, self-assembly occurs, forming a chemical sunscreen agent complex with a liposome structure. In this complex, phospholipids form bilayer vesicles, cholesterol is inserted into the bilayer to enhance the stability of the membrane structure, and algae extract adheres to the surface of the liposome particles, preventing particle aggregation through steric hindrance and significantly improving system stability. This liposome structure can efficiently encapsulate the chemical sunscreen agent, allowing it to spread evenly on the skin surface and reducing irritation caused by excessively high local concentrations. Furthermore, algae extract itself originates from algae in extreme light environments and possesses excellent photoprotective activity, synergistically enhancing the sunscreen agent and significantly improving the sun protection factor (SPF).

[0007] Specific conditions: 1) The concentration of phospholipids is between 1-9 wt%. Exceeding this concentration or falling below 1% is not conducive to the formation of stable liposome complexes. Exceeding 9 wt% is wasteful and the resulting liposomes have a thicker feel on the skin. It can also affect the HLB value of emulsifiers in sunscreen formulations, causing some unnecessary compatibility problems.

[0008] 2) First, homogenize at high speed and then slowly control the temperature: The oil solution of the sunscreen is first emulsified after mixing. As the temperature drops, its ability to dissolve oil decreases and it tends to escape the oil droplets. The surrounding phospholipids self-assemble and encapsulate the sunscreen into liposomes. Cholesterol molecules insert into the self-assembled phospholipid bilayer, which helps stabilize the phospholipid structure. Alginate extract adheres to the liposome particles to prevent the particles from colliding and agglomerating.

[0009] Optionally, the raw materials for preparing the alginate include Fucus vesiculatus extract, and the concentration of Fucus vesiculatus extract in the alginate-phospholipid mixture is 0.08-0.6 wt% based on the mass of the Fucus vesiculatus extract.

[0010] By adopting the above technical solution, the amount of algae extract, phospholipids and water depends on the solubility of the sunscreen agent to be coated, and the above ratio range is more suitable.

[0011] Optionally, the phospholipid is hydrogenated lecithin or lecithin.

[0012] Optionally, the chemical sunscreen agent is one of diethylamino hydroxybenzoyl hexyl benzoate, butyl methoxydibenzoylmethane, and ethylhexyl triazine ketone.

[0013] By adopting the above technical solution: Traditional sunscreen product formulations typically use a combination of multiple sunscreen agents. Although it's possible to dissolve multiple sunscreen agents to prepare a liposome complex of mixed sunscreen agents, this is more difficult, the encapsulation rate is not high, and the encapsulated material is prone to release and crystallization of sunscreen agents due to external conditions such as environmental temperature or shear. Limiting the process to using only one sunscreen agent, rather than a combination of sunscreen agents, can reduce the occurrence of these problems and achieve a high encapsulation rate of liposomes.

[0014] Optionally, the oil is one of dioctyl carbonate, butyloctyl salicylate, or diethylhexyl sebacate.

[0015] By adopting the above technical solution: the above is an oil, which can fully dissolve sunscreen agents. The specific selection can be made according to the structure, molecular weight and other conditions of different sunscreen agents.

[0016] Secondly, this application provides a linalool-cholesterol-phospholipid biomimetic liposome dry powder, which is obtained by drying the liposome solution prepared by the above preparation method.

[0017] Thirdly, this application provides a sunscreen composition, which adopts the following technical solution: A sunscreen composition comprising the above-mentioned alginate-cholesterol-phospholipid biomimetic liposome dry powder and a polysaccharide solution with a polysaccharide concentration of 1-2 wt%.

[0018] By adopting the above technical solution, the sunscreen agent is encapsulated in liposomes, making it easier to apply evenly. The particle size is finer, making it easier to spread on the skin. At the same time, the alginate and polysaccharide complex form a film, which allows the sunscreen agent to be spread more evenly layer by layer. Overall, the sun protection effect is improved, and it exhibits good low irritation and long-lasting film-forming properties.

[0019] Optionally, the amount of polysaccharide solution added, based on the sunscreen content, is in a weight ratio of 0.8-1.2:1 for the polysaccharide solution to the sunscreen.

[0020] By adopting the above technical solution, when the weight ratio of sunscreen agent and polysaccharide solution is within the above range, the sunscreen composition has the best sun protection effect and the best film-forming property.

[0021] Sun protection effect: When the composition of this application is added, the SPF value is increased by 5-15 compared with the control product using the same amount of sunscreen agent (without using biomimetic liposome encapsulation and polysaccharide compound).

[0022] Film-forming effect: The composition can form a film on the skin surface in about ten minutes, and the film has good elasticity and stability. The integrity of the film is well maintained under simulated sweat and friction conditions.

[0023] Optionally, the polysaccharide in the polysaccharide solution is one of β-glucan, tremella polysaccharide, sodium hyaluronate, sclerotium gum, Brunei gum, and pullulan.

[0024] In summary, this application has the following beneficial effects: This application utilizes biomimetic liposomes formed by the self-assembly of alginate, cholesterol, and phospholipids to effectively address the problem of high irritation from sunscreens by encapsulating them. Furthermore, through their inherent properties, they enable sunscreens to be distributed more evenly on the skin, thereby effectively improving the sun protection factor and overall effectiveness. When used in cosmetics and other products, they achieve the same effect but reduce the amount of chemical sunscreens used, ensuring sun protection while minimizing potential skin burden and irritation risks. In particular, the liposomes specifically utilize alginate, which adheres to the liposome particles to prevent collision and aggregation, enhances the stability of the liposomes, and provides long-term and effective sun protection. 2. The preparation method of the biomimetic liposomes in this application involves encapsulating a solid chemical sunscreen agent, and simultaneously using high-speed homogenization emulsification followed by slow stirring at controlled temperature. The difference in solubility of the solid sunscreen agent at different temperatures is utilized to reduce the solubility of the sunscreen agent, thereby allowing it to escape from the oil and be encapsulated into liposomes by the surrounding phospholipids through self-assembly. Cholesterol molecules are inserted into the self-assembled phospholipid bilayer, which helps to stabilize the phospholipid structure. 3. The sunscreen composition of this application is further compounded with polysaccharide solution from the above-mentioned biomimetic liposomes. The polysaccharide solution not only protects the stability of the sunscreen composition, but also forms a protective film that significantly improves the sunscreen effect and increases the SPF / PA value of the product. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the liposome solution in this application.

[0026] Figure 2 This is a schematic diagram of the microstructure of the liposomes prepared in Example 1 of this application.

[0027] Figure labels: 1. Bionic liposomes; 2. Sunscreen emulsion; 3. Alginate; 4. Cholesterol; 5. Phospholipids; 6. Chemical sunscreen. Detailed Implementation

[0028] The present application will be further described in detail below with reference to the embodiments. In the embodiments of the present application, the raw materials, except as described below, are commercially available: Alginate is composed of water, Fucus vesicola extract, butylene glycol, and p-hydroxyacetophenone in a conventional mixture at a weight ratio of 83.5:10:5:1.5. The Fucus vesicola extract contains ≥6% polysaccharides. It should be noted that solutions of Fucus vesicularis extract are commonly referred to as alginate. For example, a 5% solution of Fucus vesicularis extract is prepared by wetting and dispersing it with twice the amount of polyol (such as glycerol, butylene glycol, methyl propylene glycol, etc.) to facilitate dissolution in water. The remaining 85% is water as a solvent and an appropriate amount of preservative. Depending on the type or combination of preservatives, the preservative content can be 1.0-3.0%, and the water content is 84-82%. Fucus vesicularis extract solutions of different concentrations, such as 2%, 1%, 8%, and 10%, can also be prepared. A polyol-to-extract ratio of 1:2-3 is suitable. Higher concentrations result in higher viscosity; typically, a 5% concentration provides moderate viscosity, good flowability, and ease of use. Shanghai Jiakai Biotechnology Co., Ltd.'s products, Gmoist Sea-Gel and Gmoist Sea-Gel-H, also meet the requirements. The difference lies in the different preservatives and synergists, which have no significant impact on the preparation process.

[0029] Cholesterol: sourced from Nippon Seika Co., Ltd., product name CHOLESTEROL JSQI; Hydrogenated lecithin: sourced from Lipoid Kosmetik, Switzerland, model PHOSPHOLIPON®80 H; Lecithin: from Lipoid Kosmetik, Switzerland, model LIPOID S 75; Diethylaminohydroxybenzoylhexyl benzoate: sourced from Guangdong Gulait New Material Technology Co., Ltd., model GLTMOR® DHHB; Avobenzone: sourced from dsm-firmenich Switzerland Ltd, model PARSOL® 1789; Ethylhexyltriazine: sourced from dsm-firmenich Switzerland Ltd, model PARSOL® EHT; Dioctyl carbonate: sourced from BASF (China) Co., Ltd., model Cetiol® CC; Butyl octyl salicylate: sourced from Hallstar Beauty and Personal Care Solutions Company, model number HALLBRITE BHB; Diethylhexyl sebacate: sourced from NIPPON FINE CHEMICAL CO.,LTD, model FineNeo-EHS; Oat β-glucan: sourced from Shanghai Zhicheng Biotechnology Co., Ltd., model GLUCAN SP300; Tremella polysaccharide: Tremella heteropolysaccharide (WSK) was obtained from Shanghai Huiwen Biotechnology Co., Ltd. Sodium hyaluronate: sourced from Shandong Zhongshan Biotechnology Co., Ltd., model COSMHYA M180.

[0030] It should be noted that: the solid chemical sunscreen agent is partially dissolved in the oil used, and is first emulsified, then self-assembled into liposomes to encapsulate the sunscreen agent by utilizing the difference in solubility; a portion of the sunscreen agent is dissolved in the oil and emulsified but not encapsulated. Therefore, the preparation example yields a mixture of emulsified sunscreen agent emulsion and liposome solution. Therefore, the liposome solution referred to in this application refers to the aforementioned mixture of sunscreen agent emulsion and liposome solution. See [link to relevant documentation]. Figure 1 .

[0031] A method for preparing a dry powder from an alginate-cholesterol-phospholipid biomimetic liposome solution: The liposome solution prepared in the standard preparation example will show slight separation after standing for several days under normal conditions. Furthermore, the sunscreen agent may exist as liposomes or in emulsion form. To obtain a higher concentration of liposomes, liposome powder can be purified: the liposome solution is centrifuged at 4000 rpm for 30 min to obtain a layered solution, with the bottom layer being the desired liposome solution. After separating the liposome solution, the powder is prepared using methods such as drying (55-75℃), spray drying (70-90℃), or freeze drying (freezing at -40~-20℃, heating to -15~0℃ under a vacuum of 20~50 Pa to remove most of the moisture, and then drying again at 20~50 Pa and 20~40℃). In this application, drying at 55℃ is used to prepare the powder, and the sunscreen agent content of the obtained powder is quantified by HPLC.

[0032] Preparation Example 1

[0033] A biomimetic liposome solution of alginate-cholesterol-phospholipid, see [link / reference]. Figure 2 Biomimetic liposomes are prepared through the following steps: a. Preparation of a mixture of alginate and phospholipids: Mix 2g of fucus vesiculosus gum (containing 0.1g of fucus vesiculosus extract) and 1.0g of hydrogenated lecithin in 97g of water, control the phospholipid concentration in the system to be 1.0wt%, mix well under stirring conditions of 60℃ and 30rpm, and continue stirring for 15min to obtain the final product. b. Encapsulation of sunscreen agents: 1g of the chemical sunscreen agent avobenzone and 0.05g of cholesterol were dissolved in 5g of oil-based dioctyl carbonate and heated to 70℃ with stirring to obtain a sunscreen solution. The sunscreen solution (i.e., chemical sunscreen agent to phospholipid weight ratio 1:1) was added to the alginate-phospholipid mixture. The mixture was first homogenized at 3500rpm for 3min to fully refine the sunscreen droplets. Then, it was slowly stirred at 50rpm and 65℃ for 10min. The mixture was then slowly stirred and cooled to 45℃ until the alginate-phospholipid mixture self-assembled to form liposomes that fully encapsulated the chemical sunscreen agent, thus obtaining a biomimetic liposome solution. Each 106.05g of biomimetic liposome solution contains 1g of avobenzone (i.e., butyl methoxydibenzoylmethane).

[0034] Preparation Example 2

[0035] A biomimetic liposome solution of alginate-cholesterol-phospholipid is prepared by the following steps: a. Preparation of a mixture of alginate and phospholipids: Mix 8g of fucus vesiculosus gum (containing 0.4g of fucus vesiculosus extract) and 6g of hydrogenated lecithin in 86g of water, with a phospholipid concentration of 6wt% in the system. Mix well under stirring conditions of 55℃ and 45rpm for 5 minutes to obtain the final product. b. Encapsulation of sunscreen agents: Dissolve 6g of chemical sunscreen agent avobenzone and 0.3g of cholesterol in 18g of dioctyl carbonate and heat to 70℃ to obtain a sunscreen agent solution; add the sunscreen agent solution (i.e., chemical sunscreen agent and phospholipid in a 1:1 weight ratio) to the alginate-cholesterol-phospholipid mixture, first homogenize at 2500rpm for 5min to fully refine the sunscreen agent droplets, then slowly stir at 20rpm and 55℃ for 10min, then slowly stir and cool to 45℃ until the alginate-cholesterol-phospholipid mixture self-assembles to form liposomes that fully encapsulate the chemical sunscreen agent, thus obtaining a biomimetic liposome solution.

[0036] That is, each 124.3g of biomimetic liposome solution contains 6g of avobenzone.

[0037] Preparation Example 3

[0038] A biomimetic liposome solution of alginate-cholesterol-phospholipid is prepared by the following steps: a. Preparation of a mixture of alginate and phospholipids: Mix 12g of fucus vesiculosus gum (containing 0.6g of fucus vesiculosus extract) and 9g of lecithin in 79g of water, controlling the phospholipid concentration in the system to be 9wt%. Mix well under stirring conditions of 60℃ and 60rpm, and continue stirring for 20min to obtain the final product. b. Encapsulation of sunscreen: Dissolve 9g of chemical sunscreen avobenzone and 0.45g of cholesterol in 18g of butyl octyl salicylate, heat to 80℃ and stir to dissolve, thus obtaining a sunscreen solution; add the sunscreen solution (i.e., sunscreen and phospholipid in a 1:1 weight ratio) to the alginate-phospholipid mixture, first homogenize at 3500rpm for 5min to fully refine the sunscreen droplets, then slowly stir at 30rpm and 55℃ for 10min, then slowly stir and cool to 45℃ until the alginate-cholesterol-phospholipid mixture self-assembles to form liposomes that fully encapsulate the chemical sunscreen, thus obtaining a biomimetic liposome solution.

[0039] That is, each 127.45g of biomimetic liposome solution contains 9g of avobenzone.

[0040] Preparation Examples 4-9

[0041] A biomimetic liposome solution of alginate-cholesterol-phospholipid differs from Preparation Example 1 in that the amounts of each component added are different, as detailed in Table 1: Table 1

[0042] Comparative Preparation Example 1

[0043] A liposome solution, differing from Preparation Example 1 in that alginate is not added in step a and cholesterol is not added in step b.

[0044] Comparative Preparation Example 2

[0045] A liposome solution, which differs from Preparation Example 1 in that alginate is not added in step a.

[0046] Comparative preparation example 3

[0047] A liposome solution, which differs from Preparation Example 1 in that cholesterol is not added in step a.

[0048] Comparative preparation example 4

[0049] A liposome solution, which differs from Preparation Example 1 in that the amount of phospholipid added is different; the phospholipid concentration in this preparation example is 0.5 wt%.

[0050] Comparative preparation example 5

[0051] A liposome solution differs from Preparation Example 1 in that the amount of phospholipid added is different; the phospholipid concentration in this preparation example is 12.5 wt%.

[0052] Comparative preparation example 6

[0053] A liposome solution, which differs from Preparation Example 1 in that, in step b, the temperature is maintained at 50°C during slow stirring.

[0054] Example 1

[0055] A sunscreen composition, prepared as a dry powder using the liposome solution method described in the specification, comprises: 10g of the dry powder obtained from the alginate-cholesterol-phospholipid biomimetic liposome system of Preparation Example 1, and 10g of a polysaccharide solution; then 3g of 1,2-pentanediol, 1g of 1,2-hexanediol, 0.05g of tetrasodium diacetate glutamate chelating agent, and 0.7g of phenoxyethanol preservative are added; finally, water is added to bring the total amount to 100g, and the mixture is prepared as described in the specification. The polysaccharide solution has a sugar concentration of 1 wt% and is obtained by dissolving oat β-glucan in water.

[0056] It should be noted that the solvent can be selected from 1,2-pentanediol and 1,2-hexanediol; The chelating agent can be selected from disodium EDTA, tetrasodium glutamate diacetate, trisodium ethylenediamine disuccinate, octanoyl hydroxamic acid, and sodium phytate to achieve the chelation effect of metal ions; Preservatives can be selected from phenoxyethanol, benzyl alcohol, sodium benzoate, and potassium sorbate to achieve a preservative effect; The selection of the above-mentioned solvents, chelating agents, and preservatives does not significantly affect the test results of this application. This application only briefly introduces one of them as an example, but it does not affect the application of other selections in other embodiments.

[0057] Example 2

[0058] A sunscreen composition, prepared as a dry powder using the liposome solution method described in the specification, comprises: 10g of the dry powder obtained from the alginate-cholesterol-phospholipid biomimetic liposome system of Preparation Example 1, and 8g of polysaccharide solution, with a sunscreen content of 10g; then 3g of 1,2-pentanediol, 1g of 1,2-hexanediol, 0.05g of tetrasodium diacetate glutamate (a chelating agent), and 0.7g of phenoxyethanol (a preservative); finally, water is added to bring the total volume to 100g, and the mixture is prepared as described in the specification. The polysaccharide solution has a sugar concentration of 1.5 wt% and is obtained by dissolving Tremella polysaccharide in water.

[0059] Example 3

[0060] A sunscreen composition, prepared as a dry powder using the liposome solution method described in the specification, comprises: 10g of alginate-cholesterol-phospholipid biomimetic liposome solution obtained from Preparation Example 1; 2g of dry powder containing 10g of sunscreen agent and 12g of polysaccharide solution are conventionally mixed; then 0.25g of 1,2-pentanediol, 0.05g of 1,2-hexanediol, 0.05g of chelating agent tetrasodium glutamate diacetate, and 0.7g of preservative phenoxyethanol are added; finally, water is added to bring the total amount to 100g, and the mixture is conventionally mixed to obtain the final product. The polysaccharide solution has a sugar concentration of 2 wt% and is obtained by dissolving sodium hyaluronate in water.

[0061] Comparative Example 1

[0062] A sunscreen composition differs from Example 1 in that it does not contain alginate-cholesterol-phospholipid biomimetic liposomes, and uses an equal amount of avobenzone instead of the sunscreen agent avobenzone in the biomimetic liposome dry powder.

[0063] Comparative Example 2

[0064] A sunscreen composition, which differs from Example 1 in that it does not contain a polysaccharide solution.

[0065] Comparative Example 3

[0066] A sunscreen composition differs from that of Example 1 in that the added polysaccharide solution has a sugar concentration of 0.5 wt%.

[0067] Comparative Example 4

[0068] A sunscreen composition differs from that of Example 1 in that the added polysaccharide solution has a sugar concentration of 2.2 wt%.

[0069] Comparative Example 5

[0070] A sunscreen composition is prepared by conventionally mixing and homogenizing 2g of alginate (containing 0.1g of Fucus vesiculosus extract), 1g of hydrogenated lecithin, 97g of water, 1g of the chemical sunscreen agent avobenzone, 0.05g of cholesterol, and 5g of the oil dioctyl carbonate, followed by drying at 60°C for 120 minutes to obtain a mixture containing 1g of avobenzone (Note: Here, drying is only a process to increase the concentration and evaporate the water; due to the presence of oil, only a paste-like substance can be obtained in the end). Based on the avobenzone content, take a mixture containing 10g of avobenzone and 10g of polysaccharide solution, and mix them as usual; then add 3g of 1,2-pentanediol, 1g of 1,2-hexanediol, 0.05g of chelating agent tetrasodium glutamate diacetate, and 0.7g of preservative phenoxyethanol. Finally, add water to make up to a total of 100g, mix as usual, and the product is obtained. The polysaccharide solution has a sugar concentration of 1 wt% and is obtained by dissolving oat β-glucan in water.

[0071] Examples 4-11, Comparative Examples 6-11

[0072] A sunscreen composition differs from Example 1 in that the use of alginate-cholesterol-phospholipid biomimetic liposomes in the preparation of the dry powder is shown in the table below.

[0073] Table 2. Usage of biomimetic liposomes in Examples 4-11 and Comparative Examples 6-11

[0074] Irritation testing of sunscreen compositions

[0075] Irritation tests were conducted on the sunscreen compositions prepared in the examples and comparative examples. The MTT assay of HaCaT keratinocytes was used to detect and record the concentration of the chemical sunscreen agent at which a decrease in cell viability was observed. The data are recorded in Table 3. The steps are as follows: 1. Dissolve the chemical sunscreen agent to be tested in a co-solvent (DMSO or anhydrous ethanol) to obtain the test solution.

[0076] 2. Control group setup: Blank control group consisted of serum-free DMEM medium only, without cells or sunscreen; Cell control group consisted of cells, serum-free DMEM medium and corresponding concentration of solubilizer, without sunscreen; Positive control group consisted of cells, serum-free DMEM medium and 0.1% Triton X-100.

[0077] 3. Cell Seeding: Take HaCaT cells in logarithmic growth phase, discard the old culture medium in the culture flask, wash the cells twice with 2 mL PBS, add 1 mL of 0.25% trypsin-EDTA digestion solution, and incubate at 37℃ for 2-3 min. When the cells become rounded and detach under an inverted microscope, add 2 mL of complete culture medium to stop the digestion. Transfer the cell suspension to a centrifuge tube, centrifuge at 1000 rpm for 5 min, discard the supernatant, resuspend the cells in 2 mL of complete culture medium, mix a small amount of cell suspension with trypan blue staining solution at a 1:1 ratio, place on a cell counting plate, and count the number of viable cells under a microscope. Adjust the cell density to 1×10⁶ cells / year with complete culture medium. 5 Add 100 μL of cell suspension to each well of a 96-well cell culture plate. Incubate the 96-well plate at 37°C with 5% CO2 for 24 hours until the cells adhere and spread evenly.

[0078] 4. Sunscreen treatment: Remove the 96-well plate after 24 h of incubation and carefully aspirate the original culture medium from each well, avoiding contact with adherent cells. Add 100 μL of serum-free DMEM medium containing the test solution to each well, with 6 replicates per group. Place the 96-well plate back into a 37°C, 5% CO2 incubator and incubate for 24 h. After incubation, discard the supernatant. Add 150 μL of DMSO to each well and place the 96-well plate in a constant temperature shaker, shaking at low speed in the dark for 10 min. Place the 96-well plate in a microplate reader, set the detection wavelength to 570 nm and the reference wavelength to 630 nm, and measure the absorbance (OD value) of each well. Record the experimental data, calculate the relative cell viability for each concentration group using the following formula, and record the concentration of chemical sunscreen at which the relative viability decreases. Relative cell viability (%) = [(OD treatment group - OD blank group) / (OD cell control group - OD blank group)] × 100%, where: OD treatment group is the absorbance value of wells with added sunscreen; OD blank group is the absorbance value of wells containing only culture medium and no cells; OD cell control group is the absorbance value of wells containing cells and solubilizer and no sunscreen.

[0079] Table 3 Performance test results of sunscreen compositions

[0080] As shown in Table 3, in Comparative Example 1, unencapsulated avobenzone caused a decrease in cell viability at a concentration of 25 μg / mL. However, after encapsulating it in the biomimetic liposomes of this application (Examples 1-11), the concentration of sunscreen at the point of cell viability decrease increased to over 200 μg / mL, indicating a significant reduction in irritation. Comparative Examples 2-4, with no polysaccharide solution added, polysaccharide concentrations of 0.5% and 2.2%, respectively, showed less effective reduction in sunscreen irritation compared to the examples of this application. This indicates that polysaccharide solution has a synergistic effect in forming stable, low-irritation biomimetic liposomes, and a concentration range of 1-2% is more suitable.

[0081] It should be noted that in this application, the chemical sunscreen agent can be selected from avobenzone, hexyl ethylamino hydroxybenzoyl benzoate, and ethylhexyl triazine ketone; at the same time, the oil can be selected from dioctyl carbonate, butyl octyl salicylate, and diethylhexyl sebacate. The specific oil used is also related to the structure and molecular weight of the sunscreen agent, and the choice of the main oil in the final sunscreen formulation also needs to be considered. In the embodiments of this application, only one or two sunscreen agents and oils are briefly introduced as examples, but this does not affect the application of other sunscreen agents in this application.

[0082] After preparing sunscreen compositions by replacing avobenzone in Example 1 with an equal amount of ethylhexyltriazine, the results of irritation tests were compared: the sunscreen composition containing ethylhexyltriazine (not prepared as liposomes) showed a decrease in cell viability at a concentration of 5 mg / mL; the sunscreen composition containing ethylhexyltriazine liposomes did not show a decrease in cell viability at a concentration of 50 mg / mL.

[0083] Application Example 1

[0084] A sunscreen cosmetic, specifically a sunscreen lotion, comprises an oil phase, an aqueous phase, a sunscreen composition, and a complex of phenoxyethanol and ethylhexylglycerin. The components, their amounts, and manufacturers are listed in Table 4. The lotion is prepared through the following steps: Mix the components of the oil phase, heat to 80°C, and stir until completely dissolved and homogeneous; Mix the components of the aqueous phase, heat to 80°C, and stir until completely dissolved and homogeneous; The oil phase was added to the aqueous phase under stirring, and homogenized at high speed (3000 rpm) for 4 minutes to form a homogeneous emulsion. Then, the mixture was stirred and cooled to 45°C, and the sunscreen composition of Example 1 and the complex of phenoxyethanol and ethylhexylglycerin were added. The mixture was stirred until homogeneous to obtain the final product.

[0085] Table 4

[0086]

[0087] Application Example 2-22

[0088] A sunscreen cosmetic, specifically a sunscreen lotion, differs from Application Example 1 in that the sunscreen composition is used differently, as detailed in Table 5.

[0089] Table 5. Usage of the sunscreen composition in Application Examples 2-22

[0090] Performance testing of sunscreen cosmetics

[0091] Detection methods The sunscreen cosmetics prepared using the application example were subjected to the following performance tests, and the test data are recorded in Table 6.

[0092] 1. Sun protection performance testing: SPF and PFA values ​​were recorded using the COLIPA in vitro method.

[0093] 2. Film-forming properties and sweat and abrasion resistance tests: 0.02-0.03 g / cm² of sunscreen composition was evenly applied to a 1 cm² area of ​​a PMMA simulated skin plate, allowed to dry naturally, and the film-forming time was recorded. The elasticity and integrity of the film were evaluated by tensile testing and microscopic observation.

[0094] 3. Sweat and Friction Resistance Test: Referring to ISO 16244 standard, the PMMA plate coated with sunscreen cosmetics was placed in a container containing simulated sweat (composition: sodium chloride 8.0 g / L, potassium chloride 2.0 g / L, disodium hydrogen phosphate 0.5 g / L, potassium dihydrogen phosphate 0.5 g / L, pH 6.5) and immersed for 10 minutes. After removal, it was allowed to air dry. Subsequently, the plate surface was rubbed 10 times using a friction tester (loaded with 200 g weight). The presence of cracks, peeling, or sunscreen migration in the film layer was observed and recorded.

[0095] Table 6 Performance test results of sunscreen cosmetics

[0096]

[0097] As shown in Table 6, the SPF values ​​of Application Examples 1-11 (sunscreen compositions encapsulated with biomimetic liposomes according to this application) were all ≥40.5, PFA values ​​were all ≥10.2 (PA+++), film formation time was 8-10 minutes, and film integrity was >85%. Among them, Application Examples 1-4 and 7-11 had the best overall performance, with SPF values ​​of 45.2-49.1 and film integrity >95%. Application Example 12 (Comparative Example 1, without avobenzone encapsulation) had an SPF of only 25.5 and poor film formation (<50%), which was significantly different from the effect of this application. The SPF values ​​of Application Examples 13-22 (corresponding to each comparative example) were between 25.5 and 45.8, and their performance was inferior to the examples to varying degrees. This further verifies that the alginate-cholesterol-phospholipid biomimetic liposome structure of this application and its synergistic film-forming effect with the polysaccharide solution are the key to achieving high sun protection efficacy and excellent user experience.

[0098] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing a fumarole-cholesterol-phospholipid biomimetic liposome solution, characterized in that, Includes the following steps: a. Preparation of the alginate-phospholipid mixture: Mix alginate and phospholipids in water, controlling the phospholipid concentration in the system to be 1.0-9.0 wt%. Mix well under stirring conditions of 55-60℃ and 30-60 rpm for 5-20 minutes to obtain the final product. b. Encapsulation of sunscreen agents: Chemical sunscreen agents and cholesterol are dissolved in oil, heated to 70-80℃ and stirred until well mixed to obtain a sunscreen solution; Add the sunscreen solution to the alginate-phospholipid mixture, controlling the concentration of the sunscreen in the system to be 0.9-7.1 wt%. First, homogenize at high speed for 3-5 minutes at 500-3500 rpm. Then, slowly stir and cool at 45-65℃ and 20-500 rpm until the alginate-cholesterol-phospholipid mixture self-assembles to form liposomes that fully encapsulate the chemical sunscreen.

2. The method for preparing the alginate-cholesterol-phospholipid biomimetic liposome solution according to claim 1, characterized in that: The raw materials for preparing the alginate include Fucus vesiculatus extract, and the concentration of Fucus vesiculatus extract in the alginate-phospholipid mixture is 0.08-0.6 wt% based on the mass of the Fucus vesiculatus extract.

3. The method for preparing the alginate-cholesterol-phospholipid biomimetic liposome solution according to claim 1, characterized in that: The phospholipid is hydrogenated lecithin or lecithin.

4. The method for preparing the alginate-cholesterol-phospholipid biomimetic liposome solution according to claim 1, characterized in that: The chemical sunscreen agent is one of diethylamino hydroxybenzoyl hexyl benzoate, butyl methoxydibenzoylmethane, and ethylhexyl triazine ketone.

5. The method for preparing the alginate-cholesterol-phospholipid biomimetic liposome solution according to claim 1, characterized in that: The oil is one of dioctyl carbonate, butyloctyl salicylate, or diethylhexyl sebacate.

6. A biomimetic liposome powder containing alginate-cholesterol-phospholipid, characterized in that: The liposome solution prepared by the preparation method according to any one of claims 1-5 is obtained by drying.

7. A sunscreen composition, characterized in that, It includes the alginate-cholesterol-phospholipid biomimetic liposome dry powder as described in claim 6 and a polysaccharide solution with a polysaccharide concentration of 1-2 wt%.

8. The sunscreen composition according to claim 7, characterized in that: The amount of polysaccharide solution added, based on the sunscreen content, is in a weight ratio of 0.8-1.2:1 of polysaccharide solution to sunscreen.

9. The sunscreen composition according to claim 7, characterized in that: The polysaccharide in the polysaccharide solution is one of β-glucan, tremella polysaccharide, sodium hyaluronate, sclerotium gum, Brunei gum, and pullulan.

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