Liposome composite microemulsion sun-screening agent as well as preparation method and application thereof in cosmetics

Abstract

The invention belongs to the technical field of cosmetics, and particularly relates to a lipidosome composite microemulsion sun-screening agent, a preparation method thereof and application of the lipidosome composite microemulsion sun-screening agent in cosmetics. According to the invention, by selecting specific chemical sun-screening agents for matching, full-wave-band ultraviolet protection is realized, and the sun-screening effect is improved; a specific solid lipid matrix is selected, a chemical sun-screening agent is dispersed in a lipid bilayer by using a coating technology, irritation caused by direct contact with skin is reduced, meanwhile, release of the sun-screening agent is delayed, long-acting sun-screening and light stability are improved, and a product formed by combining with a specific preparation method is smaller in particle size, more uniform in component distribution and higher in stability. Therefore, a uniform film layer is formed on the surface of the skin and is tightly attached to the skin, penetration of ultraviolet rays is reduced, and the skin feeling light effect and the film-forming property at high temperature are improved. The sun-screening agent disclosed by the invention has the advantages of efficient ultraviolet protection, excellent stability and good skin feeling, and a new technical scheme is provided for the field of sun-screening cosmetics.

Description

Technical Field

[0001] The present invention belongs to the technical field of cosmetics, and particularly relates to a liposome composite microemulsion sunscreen, a preparation method thereof, and an application thereof in cosmetics. Background Art

[0002] Sunscreens are indispensable products in the field of skin care. Their main function is to protect the skin from ultraviolet (UV) radiation by physically reflecting or chemically absorbing ultraviolet rays. However, existing sunscreens still have deficiencies in aspects such as formulation design, sun protection effect, stability, and user experience.

[0003] Traditional sunscreens are mainly divided into two categories: organic chemical sunscreens and inorganic physical sunscreens. Although organic chemical sunscreens can effectively absorb UVB / UVA, they have problems such as poor photo-stability, easy decomposition, possible skin irritation or penetration of the epidermis to cause health risks after long-term use, and some sunscreens have small molecular weights and are easy to penetrate the skin and enter the blood circulation, which may cause safety hazards. While macromolecular sunscreens have high safety, they are difficult to disperse evenly and have a sticky feel. In addition, a single chemical sunscreen is usually only effective for ultraviolet rays in a specific wavelength band, and multiple sunscreens need to be compounded to achieve full-band protection, but the stability of the compounding system is poor and it is easy to stratify or crystallize. Inorganic physical sunscreens work by reflecting or scattering ultraviolet rays. Although they have broad-spectrum sun protection performance, they are easy to cause a heavy feel on the skin, white cream residue, and are difficult to disperse evenly, affecting film formation and transdermal absorption. High addition amounts are easy to cause problems such as a sticky feel on the skin and pore blockage.

[0004] In recent years, liposome technology has been widely used in sunscreen cosmetics due to its unique bilayer structure and skin compatibility. Liposomes can encapsulate hydrophilic or hydrophobic sunscreens as carriers, improve the transdermal absorption rate of active ingredients, and extend the action time through a sustained release mechanism. However, a single liposome carrier still has limitations, such as a low encapsulation rate for small molecule sunscreens, insufficient sustained release effect, and difficulty in meeting the requirements of high-SPF value products.

[0005] Therefore, it is necessary to develop a liposome composite microemulsion sunscreen with high-efficiency ultraviolet protection, excellent stability, and good skin feel, providing a new technical solution for the field of sunscreen cosmetics. Summary of the Invention

[0006] The purpose of the present invention is to provide a liposome composite microemulsion sunscreen. By selecting specific chemical sunscreens, full-band ultraviolet protection is achieved, greatly improving the sun protection effect of the prepared sunscreen. At the same time, the chemical sunscreen is encapsulated by liposomes, and combined with microemulsion technology to construct a stable and uniform sunscreen system, improving the physical stability and skin feel of the product.

[0007] To achieve the above purpose, the present invention provides the following technical solutions:

[0008] A liposome composite microemulsion sunscreen, the raw materials for its preparation, by weight percentage, include 35%-45% of a chemical sunscreen, 8%-12% of a solid lipid matrix, 8%-12% of an emulsifier, 0.4%-0.6% of an antioxidant, 2.5%-3.5% of a humectant, 0.1%-0.2% of a preservative, and water to make up the balance to 100%.

[0009] Preferably, the chemical sunscreen includes one or more of ethylhexyl methoxycinnamate, octocrylene, ethylhexyl triazone, diethylamino hydroxybenzoyl hexyl benzoate, bis-ethylhexyloxyphenol methoxyphenyl triazine, diethylhexyl butamido triazone, isoamyl p-methoxycinnamate, diethylhexyl PABA, and polysiloxane-15; more preferably, it is ethylhexyl methoxycinnamate, octocrylene, ethylhexyl triazone, diethylamino hydroxybenzoyl hexyl benzoate, bis-ethylhexyloxyphenol methoxyphenyl triazine, diethylhexyl butamido triazone, diethylhexyl PABA, and polysiloxane-15.

[0010] Preferably, the mass ratio of ethylhexyl methoxycinnamate, octocrylene, ethylhexyl triazone, diethylamino hydroxybenzoyl hexyl benzoate, bis-ethylhexyloxyphenol methoxyphenyl triazine, diethylhexyl butamido triazone, isoamyl p-methoxycinnamate, diethylhexyl PABA, and polysiloxane-15 is (4-6):(3-5):(1-3):(3-5):(2-4):(2-3):(1-2):(0.8-1.2):1.

[0011] By compounding a variety of chemical sunscreen agents, broad-spectrum protection can be achieved. While increasing the sun protection factor, it can also improve the photo-stability and the stability of microemulsion sunscreen agents, ensuring a long-term and stable sunscreen effect, and optimizing the skin feel to reduce greasiness. This may be because ethylhexyl methoxycinnamate, octocrylene, diethylhexyl PABA, and dimethicone-15 synergistically form a multi-level absorption. They can not only complement each other in the UVB protection band, but octocrylene can also stabilize the photosensitivity of ethylhexyl methoxycinnamate through hydrogen bonding, reduce its photo-degradation, and enhance the overall photo-stability. The addition of bis-ethylhexyloxyphenol methoxyphenyl triazine, diethylamino hydroxybenzoyl hexyl benzoate, and ethylhexyl triazone can absorb UVA. Acting together with components such as ethylhexyl methoxycinnamate, they can cover the entire ultraviolet protection band, fill the absorption gaps of single components. At the same time, the introduction of the triazine group can absorb and dissipate ultraviolet energy, reduce the photo-degradation of other sunscreen agents, and improve the photo-stability. The compounding of diethylamino hydroxybenzoyl hexyl benzoate and bis-ethylhexyloxyphenol methoxyphenyl triazine can not only absorb UVA, but also enhance the photo-stability through intramolecular hydrogen bonding and scatter part of the ultraviolet rays to achieve "absorption-scattering" dual protection. As the "central photo-stabilizer", ethylhexyl triazone protects all chemical sunscreen agents through triplet energy transfer. In addition, octocrylene and the emulsifier synergistically regulate the viscosity of the system, balancing the sunscreen effect and the skin feel. Dimethicone-15 has both sunscreen and film-forming functions. Its polymer structure fits well with the skin, enhancing the refreshing feeling. Dimethicone-15 can also act as a hydrophobic carrier to help disperse other oil-soluble sunscreen agents, avoid phase separation or precipitation, and improve the stability of the system. By adding an appropriate amount of isoamyl p-methoxycinnamate, replacing the UVB absorber appropriately, reducing the dependence on single components, and improving the long-term sunscreen effect of the product.

[0012] Preferably, the solid lipid matrix includes one or more of potassium cetyl phosphate, glyceryl stearate, and microcrystalline wax; More preferably, it is potassium cetyl phosphate, glyceryl stearate, and microcrystalline wax.

[0013] Preferably, the mass ratio of potassium cetyl phosphate, glyceryl stearate, and microcrystalline wax is (1-2):(2-3):1; More preferably, it is 3:5:2.

[0014] By using the compound of potassium cetyl phosphate, glyceryl stearate and microcrystalline wax, a stable solid lipid matrix can be formed, providing a good carrier environment, enhancing the embedding effect of the sunscreen agent, thus effectively reducing the precipitation of the sunscreen agent, improving the stability of the sunscreen effect and the formula stability of the product. At the same time, it can also improve the skin feel of the product, making it smoother when applied and enhancing the user experience. This may be because the compound of potassium cetyl phosphate and glyceryl stearate forms a lamellar liquid crystal structure, wrapping the sunscreen agent to form "solid lipid nanoparticles", improving the film-forming property and waterproof property. The compound of potassium cetyl phosphate and microcrystalline wax enhances the SPF value by reflecting / scattering ultraviolet rays and wrapping chemical sunscreen agents. The compound of polysorbate-60 and polyglyceryl-10 laurate not only reduces the interfacial tension but also enhances the steric hindrance, jointly stabilizing the microemulsion structure and avoiding Ostwald ripening. The addition of hydrogenated lecithin can form a liposome structure, enhancing the permeability and sustained release of the active ingredient and prolonging the sunscreen effect.

[0015] Preferably, the emulsifier includes one or more of polysorbate-60, polyglyceryl-10 laurate, and hydrogenated lecithin; More preferably, it is polysorbate-60, polyglyceryl-10 laurate, and hydrogenated lecithin.

[0016] Preferably, the mass ratio of polysorbate-60, polyglyceryl-10 laurate, and hydrogenated lecithin is (3-5):(4-6):1; More preferably, it is 4:5:1.

[0017] By compounding polysorbate-60, polyglyceryl-10 laurate, and hydrogenated lecithin, a more stable emulsification system can be formed, improving the uniformity and stability of the microemulsion and providing a better skin feel when applied. Polysorbate-60 and polyglyceryl-10 laurate can form a mixed emulsifier, enhancing the strength of the oil / water interfacial film through the synergistic effect of different HLB values, reducing delamination, and improving the stability of the sunscreen agent. The phospholipid bilayer structure of hydrogenated lecithin forms a dynamic interface with the liposome, synergistically reducing the interfacial tension to form a homogeneous microemulsion, preventing the aggregation of microemulsion particles, enhancing the centrifugal stability. At the same time, hydrogenated lecithin forms a lipid bilayer of liposomes, encapsulating the sunscreen agent inside. The light extensibility of polysorbate-60 reduces the greasiness, while promoting the fusion of liposomes with the stratum corneum and enhancing the retention of the sunscreen agent. In addition, the compound of polyglyceryl-10 laurate and microcrystalline wax can maintain the film integrity at high temperatures while providing a light skin feel. The addition of the humectants sodium hyaluronate and glycerol can balance the dry feeling of the sunscreen agent and meet the base makeup requirements such as BB cream. The humectants butylene glycol and polyglyceryl-10 laurate work together. Butylene glycol provides a refreshing and smooth feeling, and the polyol structure of the polyglyceryl ester enhances the moisturizing property, avoiding the greasiness caused by a high content of sunscreen agent and providing a soft skin feel.

[0018] Preferably, the antioxidant includes tocopheryl acetate.

[0019] Through the synergistic effect of antioxidants and chemical sunscreen agents, not only the light stability is improved, but also the duration of the sunscreen effect can be extended. This mechanism enables the product to maintain a relatively stable SPF value during long-term use, avoiding the decline of the sunscreen effect caused by oxidation. This may be because there is a synergistic effect between the antioxidant vitamin E and the chemical sunscreen agent bis-ethylhexyloxyphenol methoxyphenyl triazine. The former scavenges free radicals, and the latter reduces photodegradation through intramolecular hydrogen bonding, synergistically reducing the photodegradation rate of the chemical sunscreen agent.

[0020] Preferably, the moisturizer includes one or more of sodium hyaluronate, glycerin, and butanediol.

[0021] Preferably, the preservative is phenoxyethanol, ethylhexylglycerin, 1,2-hexanediol, and p-hydroxyacetophenone, and the mass ratio is (2-3):1:(3-4):(1-2).

[0022] The preparation method of the liposome composite microemulsion sunscreen agent includes the following steps:

[0023] S1. Preparation of the oil phase: Mix the chemical sunscreen agent, solid lipid, hydrogenated lecithin, and antioxidant, heat to 75-80 °C, and stir until completely dissolved to obtain the oil phase;

[0024] S2. Preparation of the water phase: Heat water, moisturizer, polysorbate-60, and polyglyceryl-10 laurate to 75-80 °C and stir until completely dissolved to obtain the water phase.

[0025] S3. Emulsification and homogenization: Slowly add the oil phase to the water phase, and perform high-speed shear emulsification at 5000-8000 rpm for 5-10 min to form a pre-emulsion; Pass the pre-emulsion through a high-pressure homogenizer with a pressure of 800-1000 bar and circulate it 3 times to form a uniform microemulsion;

[0026] S4. Cooling and post-treatment: Cool the uniform microemulsion to below 47 °C, add the preservative, and adjust the pH to 5.0-8.0. Transfer it to the storage tank of the microfluidic device, and after treatment by microfluidic technology, filter to obtain.

[0027] Preferably, the conditions for the microfluidic technology treatment are: the pressure is 90-110 MPa, the constant temperature water bath heating is at 40 °C, and the number of circulation times is 2-4 times.

[0028] By using microjet technology, it is possible to improve the sun protection effect while enhancing the stability of the formulation and the skin feel during use. This may be because the application of microjet technology can effectively break and homogenize emulsion particles, forming smaller particle sizes, thereby improving skin permeability and absorption. The microemulsion treated by microjet is more delicate in skin feel, non-greasy after use, and can better form a uniform protective layer on the skin surface, enhancing the sun protection effect. In addition, microjet technology can also improve the stability of the formulation, making the performance of the product more stable under high and low temperature conditions. A low temperature of 40°C can also avoid the decomposition of sunscreens caused by high temperature and reduce the risk of emulsifier denaturation, ensuring the integrity of liposomes.

[0029] The third aspect of the present invention provides the application of the liposome composite microemulsion sunscreen, which is applied in the field of cosmetics and can be used as a sunscreen and a skin protectant.

[0030] Preferably, the addition amount of the liposome composite microemulsion sunscreen in cosmetics is 1%-30%, and the addition amount in rinse-off cosmetics is 1%-10%.

[0031] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0032] 1. The present invention provides a liposome composite microemulsion sunscreen. By selecting specific chemical sunscreens, it realizes ultraviolet protection in the full wavelength range, greatly improving the sun protection effect of the prepared sunscreen. At the same time, the chemical sunscreen is encapsulated by liposomes, and a stable and uniform sunscreen system is constructed by combining microemulsion technology. The bilayer structure of liposomes is highly similar to the skin cell membrane, which can promote the penetration of the sunscreen into the stratum corneum to form a uniform and dense protective film; microemulsion technology ensures the stable dispersion of liposomes in the system, enhancing the physical stability and skin feel of the product. The sunscreen of the present invention has both high-efficiency ultraviolet protection, excellent stability and good skin feel, providing a new technical solution for the field of sunscreen cosmetics.

[0033] 2. By compounding a variety of chemical sunscreens, the present invention can achieve broad-spectrum protection. While improving the sun protection value, it can also improve the photo-stability and the stability of the microemulsion sunscreen, while ensuring a long-term stable sun protection effect and optimizing the skin feel to reduce greasiness.

[0034] 3. By using the compound of potassium cetyl phosphate, glyceryl stearate and microcrystalline wax, the present invention can form a stable solid lipid matrix, providing a good carrier environment, enhancing the embedding effect of the sunscreen, thereby effectively reducing the precipitation of the sunscreen, improving the stability of the sun protection effect and the formulation stability of the product, and at the same time improving the skin feel of the product, making it smoother when applied and enhancing the user experience.

[0035] 4. Through the synergistic effect of antioxidants and chemical sunscreens, the present invention not only enhances the photo-stability but also prolongs the duration of the sun protection effect.

[0036] 5. By compounding polysorbate-60, polyglyceryl-10 laurate, and hydrogenated lecithin, the present invention can form a more stable emulsion system, improve the uniformity and stability of the microemulsion, and provide a better skin feel during application.

[0037] 6. By using the microjet technology, the present invention can improve the sun protection effect while enhancing the stability of the formulation and the skin feel during use. Detailed Embodiments

[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0039] The raw materials used in the present invention are all commercially available. Specifically:

[0040] Microcrystalline wax, with a melting point of 68 - 70 °C and a kinematic viscosity of 7 - 10 mm 2 / s at 100 °C, from Henan Yuyang Wax Industry Co., Ltd., microcrystalline wax 70#.

[0041] Polysorbate-60, with an HLB value of 14.5 and a hydroxyl value of 80 - 105 mgKOH / g, from Hai'an Petrochemical Factory, Jiangsu Province.

[0042] Polyglyceryl-10 laurate, with an HLB value of 16.0 and a saponification value of 55 - 60 mgKOH / g, from Hubei Xingheng Industry Technology Co., Ltd.

[0043] Hydrogenated lecithin, from Shanghai Macklin Biochemical Co., Ltd.

[0044] Sodium hyaluronate, with a molecular weight of 2500 - 3500 Da, from Shanghai Macklin Biochemical Co., Ltd.

[0045] Example 1

[0046] This example provides a liposome composite microemulsion sunscreen. Its preparation raw materials, by weight percentage, are 40% chemical sunscreen, 10% solid lipid matrix, 10% emulsifier, 0.5% antioxidant, 3% humectant, 0.15% preservative, and water to make up the balance to 100%.

[0047] The chemical sunscreen agents are ethylhexyl methoxycinnamate, octocrylene, ethylhexyl triazone, diethylamino hydroxybenzoyl hexyl benzoate, bis-ethylhexyloxyphenol methoxyphenyl triazine, diethylhexyl butamido triazone, dimethyl PABA ethylhexyl ester, and polysiloxane-15, with a mass ratio of 5:4:2:4:3:2.5:1.5:1:1.

[0048] The solid lipid matrix is potassium cetyl phosphate, glyceryl stearate, and microcrystalline wax, with a mass ratio of 3:5:2.

[0049] The emulsifiers are polysorbate-60, polyglyceryl-10 laurate, and hydrogenated lecithin, with a mass ratio of 4:5:1.

[0050] The antioxidant is tocopheryl acetate.

[0051] The humectants are sodium hyaluronate, glycerol, and 1,2-butanediol, with a mass ratio of 1:25:10.

[0052] The preservatives are phenoxyethanol, ethylhexylglycerin, 1,2-hexanediol, and p-hydroxyacetophenone, with a mass ratio of 2.5:1:3.5:1.5.

[0053] The preparation method of the liposome composite microemulsion sunscreen agent comprises the following steps:

[0054] S1. Preparation of the oil phase: Mix the chemical sunscreen agents, solid lipid, hydrogenated lecithin, and antioxidant, heat to 78°C, and stir until completely dissolved to obtain the oil phase;

[0055] S2. Preparation of the water phase: Heat water, humectants, polysorbate-60, and polyglyceryl-10 laurate to 78°C and stir until completely dissolved to obtain the water phase.

[0056] S3. Emulsification and homogenization: Slowly add the oil phase to the water phase, perform high-speed shear emulsification at 6000 rpm for 8 min to form a pre-emulsion; Pass the pre-emulsion through a high-pressure homogenizer with a pressure of 900 bar and circulate it 3 times to form a uniform microemulsion;

[0057] S4. Cooling and post-treatment: Cool the uniform microemulsion to 45°C, add the preservatives, adjust the pH to 6.5, transfer it to the storage tank of the microfluidic device, and filter it after treatment by microfluidic technology.

[0058] The conditions for the microfluidic technology treatment are: a pressure of 100 MPa, a constant temperature of 40°C in a water bath, and a circulation times of 3 times.

[0059] Example 2

[0060] The differences between this example and Example 1 are as follows: For the liposome composite microemulsion sunscreen, the raw materials for its preparation, by weight percentage, are 42% of chemical sunscreen, 11% of solid lipid matrix, 11% of emulsifier, 0.5% of antioxidant, 3% of humectant, 0.15% of preservative, and water to make up the balance to 100%.

[0061] Comparative Example 1

[0062] The differences between this comparative example and Example 1 are as follows: The chemical sunscreens are ethylhexyl methoxycinnamate and octocrylene, and the mass ratio is 5:4.

[0063] Comparative Example 2

[0064] The differences between this comparative example and Example 1 are as follows: The solid lipid matrix is glyceryl stearate.

[0065] Comparative Example 3

[0066] The differences between this comparative example and Example 1 are as follows: For the liposome composite microemulsion sunscreen, the raw materials for its preparation, by weight percentage, are 40% of chemical sunscreen, 10% of solid lipid matrix, 10% of emulsifier, 3% of humectant, 0.15% of preservative, and water to make up the balance to 100%.

[0067] Comparative Example 4

[0068] The differences between this comparative example and Example 1 are as follows: The emulsifier is polysorbate - 60.

[0069] Comparative Example 5

[0070] The differences between this comparative example and Example 1 are as follows: The chemical sunscreens are ethylhexyl methoxycinnamate, octocrylene, ethylhexyl triazone, diethylamino hydroxybenzoyl hexyl benzoate, bis - ethylhexyloxyphenol methoxyphenyl triazine, diethylhexyl butamido triazone, dimethyl PABA ethylhexyl ester, and polysiloxane - 15, and the mass ratio is 5:4:2:2:1:2.5:1.5:1:1.

[0071] Comparative Example 6

[0072] The differences between this comparative example and Example 1 are as follows: The chemical sunscreens are ethylhexyl methoxycinnamate, ethylhexyl triazone, diethylamino hydroxybenzoyl hexyl benzoate, bis - ethylhexyloxyphenol methoxyphenyl triazine, diethylhexyl butamido triazone, dimethyl PABA ethylhexyl ester, and polysiloxane - 15, and the mass ratio is 5:2:4:3:2.5:1.5:1:1.

[0073] Comparative Example 7

[0074] The differences between this comparative example and Example 1 are as follows: S4, Cooling and Post-treatment: The homogeneous microemulsion was cooled to 45 °C, a preservative was added, and the pH was adjusted to 6.5. After continuing to stir at 400 rpm for 30 min, filtration was carried out to obtain the product.

[0075] Performance Test

[0076] In vitro SPF determination: The microemulsion sunscreen sample was evenly coated on a PMMA plate at a dosage of 2 mg / cm2, and the transmittance at wavelengths of 290 - 400 nm was measured. The SPF value was calculated according to ISO 24443:2021. Long-term SPF retention rate test: The microemulsion sunscreen sample was stored at 50 °C for 30 days, and its SPF value was tested. The retention rate = SPF value after 30 days / initial SPF value × 100%. High and low temperature cycle stability test: Referring to GB / T 29665-2013, the microemulsion sunscreen sample was stored at -20 °C for 24 h and then heated to 50 °C and stored for 24 h. This was one cycle. After 10 cycles, it was observed whether there were phenomena such as stratification, precipitation, color change, turbidity, etc. If not, it was considered qualified. Centrifugal stability test: The microemulsion sunscreen sample was centrifuged at 3000 rpm for 30 min, and it was observed whether there were phenomena such as oil phase separation, stratification, precipitation, turbidity, etc. If not, it was considered qualified. Sensory test: Twenty volunteers aged between 25 - 55, with half male and half female, and skin types covering dry, oily, and combination types were selected. They used the microemulsion sunscreens of Examples 1 - 2 and Comparative Examples 1 - 7 respectively, and were scored from four dimensions: ductility, greasiness, film-forming speed, and residue feeling. Each dimension was scored from 1 to 5 points, and the higher the score, the better the sensory experience. Take the sum of the average scores of each dimension / 4, and then take the average value of the 20 volunteers, which is the sensory score. The results are shown in Table 1.

[0077] Table 1 Measurement Results

[0078]

[0079] According to statistics, the liposome composite microemulsion sunscreen prepared in Examples 1-2 of the present invention has a high SPF value, stable long-term sunscreen effect, excellent physical and chemical stability of the product, good skin feel, high sensory score, good ductility, non-greasy, fast film-forming speed, and no residue. In Comparative Example 1, there are only two UVB sunscreens, and the compounding is unreasonable, resulting in poor sunscreen effect and low stability, and slow film-forming; in Comparative Example 2, the solid lipid mechanism is single, only stearic acid glycerol ester, and the embedding effect of the sunscreen is poor, resulting in the precipitation of the sunscreen, affecting the long-term sunscreen stability of the product. At the same time, the liposome ruptures, and there is obvious stratification after centrifugation, with a feeling of clogged pores; in Comparative Example 3, no oxidant is contained. Although it does not affect the SPF value much, it will affect the long-term sunscreen effect, and there will be stratification during high and low temperature cycling. Centrifugation causes liposome aggregation, with a slight sticky feeling; in Comparative Example 4, the emulsifier compounding is unreasonable, only polysorbate-60, and the long-term retention rate of the sunscreen effect is low. During the physical and chemical stability test, it is completely stratified, with a sticky and uneven film-forming feeling during use; in Comparative Example 5, the proportions of diethylamino hydroxybenzoyl benzoate and bis-ethylhexyloxyphenol methoxyphenyl triazine are small, and the UVA / UVB ratio is unbalanced, affecting the long-term SPF retention rate, with a slight whitening phenomenon during use; in Comparative Example 6, octocrylene is not added, the SPF value is slightly reduced, and the retention rate drops significantly, and at the same time the film-forming is slower; in Comparative Example 7, no microemulsification technology is used. Although it does not affect the immediate SPF value and the high and low temperature cycling effect, it affects the long-term SPF value retention rate. At the same time, since the microjet technology can improve particle dispersion, there is precipitation during the centrifugation experiment of Comparative Example 7 without the microjet technology. Therefore, the liposome composite microemulsion sunscreen prepared by the method described in the present application not only has high-efficiency ultraviolet protection, but also has a good long-term sunscreen effect, excellent stability, and good skin feel during use. The excellent stability and good skin feel provide a new technical solution for the field of sunscreen cosmetics.

[0080] The above are the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle described in the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A liposome composite microemulsion sunscreen, characterized in that, The raw materials for its preparation, by weight percentage, include: 35%-45% of chemical sunscreen agents, 8%-12% of solid lipid matrix, 8%-12% of emulsifiers, 0.4%-0.6% of antioxidants, 2.5%-3.5% of humectants, 0.1%-0.2% of preservatives, and water to make up the balance to 100%; the chemical sunscreen agents include one or more of ethylhexyl methoxycinnamate, octocrylene, ethylhexyl triazone, diethylamino hydroxybenzoyl hexyl benzoate, bis-ethylhexyloxyphenol methoxyphenyl triazine, diethylhexyl butamido triazone, isoamyl p-methoxycinnamate, diethylmethyl PABA ethylhexyl ester, and polysiloxane-15.

2. The liposome composite microemulsion sunscreen agent according to claim 1, characterized in that, The chemical sunscreen agents are ethylhexyl methoxycinnamate, octocrylene, ethylhexyl triazone, diethylamino hydroxybenzoyl hexyl benzoate, bis-ethylhexyloxyphenol methoxyphenyl triazine, diethylhexyl butamido triazone, isoamyl p-methoxycinnamate, diethylmethyl PABA ethylhexyl ester, and polysiloxane-15.

3. The liposome composite microemulsion sunscreen agent according to claim 2, wherein The mass ratio of ethylhexyl methoxycinnamate, octocrylene, ethylhexyl triazone, diethylamino hydroxybenzoyl hexyl benzoate, bis-ethylhexyloxyphenol methoxyphenyl triazine, diethylhexyl butamido triazone, isoamyl p-methoxycinnamate, diethylmethyl PABA ethylhexyl ester, and polysiloxane-15 is (4-6):(3-5):(1-3):(3-5):(2-4):(2-3):(1-2):(0.8-1.2):

1.

4. The liposome composite microemulsion sunscreen agent according to claim 1, wherein, The solid lipid matrix includes one or more of potassium cetyl phosphate, glyceryl stearate, and microcrystalline wax.

5. The liposome composite microemulsion sunscreen agent according to claim 1, wherein The emulsifiers include one or more of polysorbate-60, polyglyceryl-10 laurate, and hydrogenated lecithin.

6. The liposome composite microemulsion sunscreen agent according to claim 1, characterized in that, The humectants include one or more of sodium hyaluronate, glycerin, and butanediol.

7. The liposome composite microemulsion sunscreen agent according to claim 1, wherein The preservative is phenoxyethanol, ethylhexylglycerin, 1,2-hexanediol, and p-hydroxyacetophenone, and the mass ratio is (2-3):1:(3-4):(1-2).

8. A preparation method of the liposome composite microemulsion sunscreen agent according to any one of claims 1 to 7, characterized in that, It includes the following steps: S1. Preparation of oil phase: Mix the chemical sunscreen agents, solid lipid, hydrogenated lecithin, and antioxidant, heat to 75-80 °C and stir until completely dissolved to obtain the oil phase. S2. Preparation of water phase: Heat water, humectant, polysorbate-60, and polyglyceryl-10 laurate to 75-80 °C and stir until completely dissolved to obtain the water phase. S3. Emulsification and homogenization: Slowly add the oil phase to the water phase, and perform high-speed shear emulsification at 5000-8000 rpm for 5-10 min to form a pre-emulsion; circulate the pre-emulsion through a high-pressure homogenizer with a pressure of 800-1000 bar for 3 times to form a uniform microemulsion. S4. Cooling and post-treatment: Cool the uniform microemulsion to below 47 °C, add the preservative, and adjust the pH to 5.0-8.

0. Transfer it to the storage tank of the microfluidic device, and after treatment by microfluidic technology, filter to obtain the product.

9. The preparation method of the liposome composite microemulsion sunscreen agent according to claim 8, characterized in that, The conditions for the microfluidic technology treatment are: the pressure is 90-110 MPa, the constant temperature water bath heating is at 40 °C, and the number of circulation times is 2-4 times.

10. Use of the liposome composite microemulsion sunscreen agent according to any one of claims 1 to 7 in the field of cosmetics.

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