Liposome delivery system with high loading rate and oxidation resistance, and preparation method and application thereof

Abstract

The application belongs to the technical field of cosmetics, and particularly relates to a liposome delivery system with high loading rate and oxidation resistance, and a preparation method and application thereof. The liposome delivery system comprises the following components in percentage by mass: 4-10% of a complex film material, 0.3-2% of carboxymethyl deacetyl chitin, 0.1-2% of tocopherol acetate, 0.1-2% of thioctic acid, 0.1-2% of carnosic acid, 50-80% of glycerol, 2-10% of ethoxydiglycol, 2-10% of caprylic / capric triglyceride, 2-3% of pH buffer, 0.1-10% of active ingredients, and the balance of water. The application optimizes the component proportion of the film material, the solvent system, the antioxidant, and the surface active / stabilizing agent, utilizes the synergistic effect among the components, realizes efficient wrapping of the active ingredients, and improves the oxidation resistance and storage stability of the liposome.

Description

Technical Field

[0001] This invention belongs to the field of cosmetic technology, specifically relating to a liposome delivery system with high loading rate and antioxidant properties, its preparation method, and its application. Background Technology

[0002] Liposomes are closed vesicles with a bilayer membrane structure formed by the self-assembly of amphiphilic molecules such as phospholipids in an aqueous phase. Due to their structural characteristics similar to biological membranes, they are widely used as delivery carriers for active ingredients in pharmaceuticals and cosmetics. Compared to traditional formulations, liposome encapsulation of active ingredients offers multiple advantages: protecting unstable ingredients (such as retinol and vitamin C) from oxidative degradation; achieving sustained and controlled release of active substances; improving skin permeability and targeting of ingredients; and reducing the potential irritation to the skin from some irritating ingredients.

[0003] However, existing cosmetic liposome technology still faces many problems in practical applications, which seriously limit its industrial application: (1) Limited encapsulation rate and poor universality: Conventional liposome membrane materials have a single structural design and insufficient solubility compatibility with solvent systems. They are not capable of simultaneously and efficiently encapsulating hydrophilic, lipophilic and amphiphilic components. In particular, for complex active ingredients with large polarity differences, it is difficult to achieve a high encapsulation rate and cannot meet the needs of multiple active ingredients in cosmetic formulations; (2) Poor physical and chemical stability: Liposomes are prone to aggregation, fusion, precipitation or particle size growth during storage, which leads to system delamination and instability. In addition, the liposome membrane material itself is easily oxidized and hydrolyzed, causing the vesicle structure to break down. (3) Inadequate antioxidant protection system: Traditional antioxidants are mostly single-component additives, which can only act on the single phase region of aqueous or oil phase. It is difficult to form a comprehensive and multi-level antioxidant protection for the entire liposome system (including membrane material, internal aqueous phase, oil phase and encapsulated active ingredients). The protective efficacy of the core functional ingredients is insufficient, which can easily lead to the inactivation and failure of active ingredients. (4) Insufficient skin delivery efficiency: The membrane material affinity and solvent permeation promotion design of conventional liposomes are unreasonable, which makes the skin transdermal absorption efficiency of active ingredients low and the retention ability in the epidermis / dermis layer of the skin weak, which cannot fully exert the local skin care effect.

[0004] Therefore, developing a liposome delivery system that achieves high encapsulation efficiency, strong antioxidant properties, and high storage stability through the synergistic effect of multiple components, and also brightens skin tone, is of great significance for promoting the industrial application of active ingredients in cosmetics by enabling broad-spectrum and efficient encapsulation and skin delivery of active ingredients with different polarities. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a liposome delivery system with high loading capacity and antioxidant properties, along with its preparation method and applications. By optimizing the composition ratio of the membrane material, solvent system, antioxidant, and surfactant / stabilizer, and utilizing the synergistic effect between the components, efficient encapsulation of active substances is achieved, while simultaneously enhancing the antioxidant properties and storage stability of the liposomes.

[0006] To achieve the above objectives, the specific technical solution adopted by the present invention is as follows: A high-loading, antioxidant liposome delivery system comprises, by mass percentage: 4%-10% composite membrane material, 0.3%-2% carboxymethyl deacetylated chitosan, 0.1%-2% tocopheryl acetate, 0.1%-2% lipoic acid, 0.1%-2% oxalic acid, 50%-80% glycerol, 2%-10% ethoxydiethylene glycol, 2%-10% caprylic / capric triglyceride, 2%-3% pH buffer, 0.1%-10% active ingredient, and the balance being water.

[0007] Preferably, the composite membrane material is composed of hydrogenated lecithin, cholesterol, and phytosterol esters in a mass ratio of 1:0.3-0.5:0.4-0.7.

[0008] Preferably, the mass ratio of glycerol, ethoxydiethylene glycol and caprylic / capric triglyceride is 15-25:1.5-2.5:1.

[0009] In the composite membrane, hydrogenated lecithin and cholesterol form a basic bilayer. The hydrophobic chains of phytosterol esters are embedded in the membrane layer to enhance rigidity and form hydrogen bonds with the phosphate groups of hydrogenated lecithin. At the same time, they interact electrostatically with the carboxyl groups of carboxymethyl deacetylated chitosan, which reduces the membrane porosity, significantly improves the loading rate, and prevents the leakage of active materials.

[0010] Carboxymethyl deacetylated chitosan acts as a stabilizer, effectively preventing the aggregation and fusion of liposome particles. Through electrostatic interactions and hydrogen bonds, it forms a hydrophilic gel network on the surface of liposomes, which not only greatly enhances long-term dispersion stability, but its weak positive charge also facilitates the adsorption and retention of liposomes on negatively charged skin surfaces.

[0011] Tocopheryl acetate, lipoic acid, and oxalic acid serve as antioxidants. Tocopheryl acetate, as a lipid-soluble antioxidant, precisely targets the lipid bilayer due to its excellent lipid affinity. During liposome storage, its esterification structure effectively protects the phenolic hydroxyl groups from oxidation, enhancing the system's chemical stability. Upon application to the skin, it slowly releases tocopherol through skin surface esterase activity or the system's microenvironment, continuously scavenging lipid-phase free radicals and preventing membrane material oxidation and hydrolysis, achieving dual antioxidant protection of "storage stability + application-controlled release." Lipoic acid, possessing both hydrophilic and lipophilic properties, functions at the membrane-water interface, blocking free radical transphase transport. Oxalic acid forms hydrogen bonds with the active ingredient, directly protecting the core active ingredient from oxidation. These three components synergistically form a three-tiered antioxidant protection network: "membrane phase-interface-core."

[0012] The solvent system consists of glycerol, ethoxydiethylene glycol, and caprylic / capric triglyceride. This ternary solvent system works synergistically to form a highly efficient co-solubility environment for various active ingredients: glycerol and ethoxydiethylene glycol provide strong polarity and hydrogen bonding dissolution capabilities, while caprylic / capric triglyceride provides suitable lipid phase dissolution space, allowing different polar active ingredients to be directionally enriched in the corresponding regions of the membrane structure, achieving broad-spectrum and efficient encapsulation.

[0013] Preferably, the pH buffer is a phosphate buffer or a citrate-sodium citrate buffer.

[0014] Preferably, the active ingredient is selected from one or more of hydrophilic active ingredients, lipophilic active ingredients, and amphiphilic active ingredients.

[0015] This invention also relates to a method for preparing the above-mentioned high-loading, antioxidant liposome delivery system, comprising the following steps: (1) The composite membrane material, tocopheryl acetate, oxalic acid and caprylic / capric triglyceride were dissolved in ethoxydiethylene glycol and stirred to obtain the oil phase; (2) Mix glycerol, carboxymethyl deacetylated chitosan, lipoic acid and water, add pH buffer, stir to obtain aqueous phase; (3) Add the oil phase to the aqueous phase, shear emulsify, homogenize, and discharge to obtain the product; When the active ingredient is lipophilic, the active ingredient is added in step (1); When the active ingredient is a hydrophilic active ingredient, the active ingredient is added in step (2).

[0016] Preferably, the stirring temperature in steps (1) and (2) is 50-60℃, the stirring time is 20-30 min, and the stirring speed is 400-600 rpm.

[0017] Preferably, the shearing speed in step (3) is 8000-12000 rpm, the shearing time is 10-15 min, the homogenization pressure is 80-120 MPa, the cycle is 3-5 times, and the discharge temperature is 20-25℃.

[0018] The present invention also relates to the application of the above-mentioned high loading rate and antioxidant liposome delivery system in cosmetics, wherein the dosage form of the cosmetic is selected from essential oils, eye creams, face creams, lotions or serums.

[0019] Preferably, the cosmetic also includes cosmetically acceptable excipients, which include one or more of moisturizers, emulsifiers, thickeners, and preservatives.

[0020] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention greatly enhances the solubility and containment capacity of active ingredients with different polarities by optimizing the composite membrane material (hydrogenated lecithin, cholesterol and phytosterol esters) and solvent (glycerol, ethoxydiethylene glycol and caprylic / capric triglycerides). The composite membrane material forms a dense and flexible bilayer structure through hydrogen bonding and electrostatic interaction between the components; the multi-element solvent system can synergistically dissolve active ingredients with different polarities, and the two work together to achieve efficient encapsulation of active ingredients, significantly improving the encapsulation rate.

[0021] (2) This invention creatively employs a triple synergistic antioxidant network composed of tocopheryl acetate, lipoic acid, and sarsaparilla acid. These three components target the lipid membrane, the membrane-water interface, and the active ingredients themselves, respectively, forming a comprehensive, multi-layered antioxidant protection from the outside to the core, and from the lipid phase to the aqueous phase. This significantly delays the oxidation of the liposomes themselves and the inactivation of the encapsulated active ingredients, greatly enhancing the product's long-lasting efficacy. Simultaneously, it effectively scavenge DPPH free radicals, inhibits lipid peroxidation, and reduces oxidative pigmentation and lipofuscin accumulation, thereby improving dullness and yellowing of the skin from the source. Furthermore, the system exhibits high encapsulation efficiency and synergistic delivery capabilities for hydrophilic whitening ingredients (such as arbutin) and lipophilic brightening ingredients (such as retinyl palmitate and 4-butylresorcinol), achieving a skin-brightening skincare effect. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to specific embodiments. The following embodiments are not intended to limit the present invention, but only to illustrate the present invention. Unless otherwise specified, the experimental methods used in the following embodiments are generally performed under conventional conditions. Unless otherwise specified, the materials and reagents used in the following embodiments are commercially available.

[0023] Information on the source of raw materials is shown in Table 1.

[0024] Table 1 Raw Material Source Information

[0025] Example 1 A high-loading, antioxidant liposome delivery system, comprising the following raw materials by mass percentage: Hydrogenated lecithin 3.5%, cholesterol 1.4%, phytosterol esters 2.1%, carboxymethyl deacetylated chitosan 1%, tocopheryl acetate 1%, lipoic acid 0.5%, carboxylic acid 0.5%, glycerol 60%, ethoxydiethylene glycol 6%, caprylic / capric triglyceride 4%, PBS buffer (pH 6.5) 2.5%, active ingredients 5.5% (arbutin 5%, retinyl palmitate 0.5%), and the balance being water.

[0026] The preparation method of the above liposome delivery system is as follows: (1) Hydrogenated lecithin, cholesterol, phytosterol ester, tocopheryl acetate, saurolyl oleate and caprylic / capric triglyceride were dissolved in ethoxydiethylene glycol and stirred at 55°C and 500 rpm for 25 min. Retinyl palmitate was added and stirring was continued for 10 min to obtain the oil phase.

[0027] (2) Mix glycerol, carboxymethyl deacetylated chitosan, thioctic acid and water, add PBS buffer, stir at 55°C and 500 rpm for 25 min, add arbutin and stir to dissolve, and obtain the aqueous phase.

[0028] (3) Slowly add the oil phase to the water phase, shear emulsify at 10,000 rpm for 12 min, homogenize and cycle at 100 MPa 4 times, and discharge at 23℃ to obtain the product.

[0029] Example 2 A high-loading, antioxidant liposome delivery system, comprising the following raw materials by mass percentage: Hydrogenated lecithin 4.5%, cholesterol 1.8%, phytosterol esters 2.7%, carboxymethyl deacetylated chitosan 1.8%, tocopheryl acetate 1.2%, lipoic acid 0.7%, sarsaparilla acid 0.5%, glycerol 70%, ethoxydiethylene glycol 5%, caprylic / capric triglyceride 3%, citrate-sodium citrate buffer (pH 6.0) 2.5%, active ingredient 5% (4-butylresorcinol 5%), and the balance being water.

[0030] The preparation method of the above liposome delivery system is as follows: (1) Hydrogenated lecithin, cholesterol, phytosterol ester, tocopheryl acetate, oxalic acid and caprylic / capric triglyceride were dissolved in ethoxydiethylene glycol and stirred at 60°C and 600 rpm for 20 min. Then, 4-butylresorcinol was added and stirred for another 8 min until dissolved to obtain the oil phase.

[0031] (2) Mix glycerol, carboxymethyl deacetylated chitosan, thioctic acid and water, add citrate-sodium citrate buffer, stir at 60°C and 600 rpm for 20 min to obtain the aqueous phase.

[0032] (3) Slowly add the oil phase to the aqueous phase, shear emulsify at 12000 rpm for 10 min, homogenize and cycle at 120 MPa 3 times, and discharge at 25℃ to obtain the liposome delivery system.

[0033] Example 3 A high-loading, antioxidant liposome delivery system, comprising the following raw materials by mass percentage: Hydrogenated lecithin 2%, cholesterol 0.6%, phytosterol esters 1.4%, carboxymethyl deacetylated chitosan 0.4%, tocopheryl acetate 0.75%, lipoic acid 0.45%, sarsaparilla acid 0.3%, glycerol 60%, ethoxydiethylene glycol 9%, caprylic / capric triglyceride 4%, citrate-sodium citrate buffer (pH 6.0) 2%, active ingredient 1% (ceramide NP 1%) and balance water.

[0034] The preparation method of the above liposome delivery system is as follows: (1) Hydrogenated lecithin, cholesterol, phytosterol ester, tocopheryl acetate, sarsaparilla acid and caprylic / capric triglyceride were dissolved in ethoxydiethylene glycol and stirred at 50°C and 400 rpm for 30 min. Ceramide NP was added and stirred for another 12 min until dissolved to obtain the oil phase.

[0035] (2) Mix glycerol, carboxymethyl deacetylated chitosan, thioctic acid and water, add citrate-sodium citrate buffer, stir at 50°C and 400 rpm for 30 min to obtain the aqueous phase.

[0036] (3) Slowly add the oil phase to the water phase, shear emulsify at 8000 rpm for 15 min, homogenize and cycle at 80 MPa 5 times, and discharge at 20℃ to obtain the product.

[0037] Example 4 A high-loading, antioxidant liposome delivery system, comprising the following raw materials by mass percentage: Hydrogenated lecithin 3.5%, cholesterol 1.4%, phytosterol esters 2.1%, carboxymethyl deacetylated chitosan 1%, tocopheryl acetate 1%, lipoic acid 0.5%, sarsaparilla acid 0.5%, glycerol 65%, ethoxydiethylene glycol 6%, caprylic / capric triglyceride 4%, PBS buffer (pH 6.5) 2.5%, active ingredient 5% (oil-soluble coenzyme Q10 5%), and the balance being water.

[0038] The preparation method of the above liposome delivery system is as follows: (1) Hydrogenated lecithin, cholesterol, phytosterol ester, tocopheryl acetate, sarsaparilla acid and caprylic / capric triglyceride were dissolved in ethoxydiethylene glycol and stirred at 55°C and 500 rpm for 25 min. Oil-soluble coenzyme Q10 was added and stirred for another 10 min to obtain the oil phase.

[0039] (2) Mix glycerol, carboxymethyl deacetylated chitosan, thioctic acid and water, add PBS buffer, stir at 55°C and 500 rpm for 25 min to obtain the aqueous phase.

[0040] (3) Slowly add the oil phase to the water phase, shear emulsify at 10,000 rpm for 12 min, homogenize and cycle at 100 MPa 4 times, and discharge at 23℃ to obtain the product.

[0041] Comparative Example 1 The only difference between this comparative example and Example 1 is the ratio of the composite membrane material (hydrogenated lecithin: cholesterol: phytosterol ester = 1:0.6:0.3), specifically: 3.7% hydrogenated lecithin, 2.2% cholesterol, and 1.1% phytosterol ester. The remaining components, ratios, and preparation methods are the same as in Example 1.

[0042] Comparative Example 2 The only difference between this comparative example and Example 1 is the composition of the composite membrane (only hydrogenated lecithin and cholesterol), specifically: The ingredients, by weight percentage, are: 5% hydrogenated lecithin, 2% cholesterol, 1% carboxymethyl deacetylated chitosan, 1% tocopheryl acetate, 0.5% lipoic acid, 0.5% carboxylic acid, 60% glycerol, 6% ethoxydiethylene glycol, 4% caprylic / capric triglyceride, 2.5% PBS buffer (pH 6.5), 5.5% active ingredients (5% arbutin, 0.5% retinyl palmitate), and the balance being water.

[0043] The preparation method is different from Example 1 except for step (1), which is as follows: hydrogenated lecithin, cholesterol, tocopheryl acetate, oxalic acid and caprylic / capric triglyceride are dissolved in ethoxydiethylene glycol, stirred at 55°C and 500 rpm for 25 min, retinyl palmitate is added, and stirring is continued for 10 min to obtain the oil phase.

[0044] Comparative Example 3 The only difference between this comparative example and Example 1 is the composition of the composite membrane (only phytosterol esters), specifically: The ingredients, by weight percentage, are: 7% phytosterol esters, 1% carboxymethyl deacetylated chitosan, 1% tocopheryl acetate, 0.5% lipoic acid, 0.5% carboxylic acid, 60% glycerol, 6% ethoxydiethylene glycol, 4% caprylic / capric triglycerides, 2.5% PBS buffer (pH 6.5), 5.5% active ingredients (5% arbutin, 0.5% retinyl palmitate), and the balance being water.

[0045] The preparation method is different from Example 1 except for step (1), which is as follows: plant sterol esters, tocopheryl acetate, sarsaparilla acid and caprylic / capric triglycerides are dissolved in ethoxydiethylene glycol, stirred at 55°C and 500 rpm for 25 min, retinyl palmitate is added, and stirring is continued for 10 min to obtain the oil phase.

[0046] Comparative Example 4 The only difference between this comparative example and Example 1 is that carboxymethyl deacetylated chitosan is replaced with polyvinylpyrrolidone (PVP K90).

[0047] Preparation method: The only difference from Example 1 is step (2), which is: glycerol, polyvinylpyrrolidone (PVP K90), thioctic acid and water are mixed, PBS buffer is added, and the mixture is stirred at 55°C and 500 rpm for 25 min. Arbutin is added and stirred to dissolve, and an aqueous phase is obtained.

[0048] Comparative Example 5 The only difference between this comparative example and Example 1 is that it does not contain thioctic acid, which is added to oxalic acid.

[0049] The ingredients, by weight percentage, are: hydrogenated lecithin 3.5%, cholesterol 1.4%, phytosterol esters 2.1%, carboxymethyl deacetylated chitosan 1%, tocopheryl acetate 1%, sarsaparilla acid 1%, glycerol 60%, ethoxydiethylene glycol 6%, caprylic / capric triglycerides 4%, PBS buffer (pH 6.5) 2.5%, active ingredients 5.5% (arbutin 5%, retinyl palmitate 0.5%), and the balance being water.

[0050] The preparation method is different from that in Example 1 except for step (2), which is as follows: glycerol, carboxymethyl deacetylated chitosan and water are mixed, PBS buffer is added, and the mixture is stirred at 55°C and 500 rpm for 25 min. Arbutin is added and stirred to dissolve, and an aqueous phase is obtained.

[0051] Comparative Example 6 The only difference between this comparative example and Example 1 is that oxalic acid is not added, but its amount is added to lipoic acid.

[0052] The ingredients, by weight percentage, are: hydrogenated lecithin 3.5%, cholesterol 1.4%, phytosterol esters 2.1%, carboxymethyl deacetylated chitosan 1%, tocopheryl acetate 1%, lipoic acid 1%, glycerol 60%, ethoxydiethylene glycol 6%, caprylic / capric triglyceride 4%, PBS buffer (pH 6.5) 2.5%, active ingredients 5.5% (arbutin 5%, retinyl palmitate 0.5%), and the balance being water.

[0053] The preparation method is different from Example 1 except for step (1), which is as follows: hydrogenated lecithin, cholesterol, phytosterol ester, tocopheryl acetate and caprylic / capric triglyceride are dissolved in ethoxydiethylene glycol, stirred at 55°C and 500 rpm for 25 min, retinyl palmitate is added, and stirring is continued for 10 min to obtain the oil phase.

[0054] Comparative Example 7 The only difference between this comparative example and Example 1 is that the solvent system lacks ethoxydiethylene glycol (containing only glycerol and caprylic / capric triglycerides). The raw materials, by mass percentage, are: hydrogenated lecithin 3.5%, cholesterol 1.4%, phytosterol esters 2.1%, carboxymethyl deacetylated chitosan 1%, tocopheryl acetate 1%, lipoic acid 0.5%, sarsaparilla acid 0.5%, glycerol 60%, caprylic / capric triglycerides 10%, PBS buffer (pH 6.5) 2.5%, active ingredients 5.5% (arbutin 5%, retinyl palmitate 0.5%), and the balance being water.

[0055] Preparation method: Hydrogenated lecithin, cholesterol, phytosterol esters, tocopheryl acetate, sarsaparilla acid and caprylic / capric triglycerides were mixed and stirred at 55°C and 500 rpm for 25 min. Retinyl palmitate was added and stirring was continued for 10 min to obtain the oil phase. The remaining steps were the same as in Example 1.

[0056] Comparative Example 8 The only difference between this comparative example and Example 1 is the ratio of glycerol, ethoxydiethylene glycol, and caprylic / capric triglyceride in the solvent system. Specifically, the ratio is 40% glycerol, 20% ethoxydiethylene glycol, and 10% caprylic / capric triglyceride. The remaining components, amounts, and preparation methods are the same as in Example 1.

[0057] Effect test Test Example 1: Coverage Rate Test Take 2 mL of liposome samples from Examples 1-4 and Comparative Examples 1-8 respectively, add 2 mL of pre-cooled PBS buffer (pH 6.5), and mix gently; centrifuge at 3000×g for 10 min, carefully discard the supernatant (to remove loosely adsorbed free components), resuspend the precipitate in 2 mL of PBS, and wash once.

[0058] Then, centrifuge at 100,000 × g and 4 °C for 60 min, and collect 1.5 mL of the supernatant (containing residual free active ingredients), labeled as the "free phase"; add 1.0 mL of methanol-acetonitrile (1:1) to the remaining precipitate, vortex to mix, and sonicate for 10 min (300 W, intermittent mode) to ensure complete demulsification of the liposomes, labeled as the "coated phase"; determine the concentration of active ingredients in the free phase and coated phase separately using HPLC; calculate the coating rate: coating rate (%) = C 包覆相 / (C 包覆相 +C 游离相 )×100%.

[0059] The test results are shown in Table 2.

[0060] Table 2. Coverage Rate Test Results

[0061] Examples 1-4 all showed an encapsulation rate ≥82.6%, demonstrating that the system of the present invention has a high encapsulation capacity for active ingredients of different polarities. Comparative Example 1, due to an imbalance in the composite membrane material ratio, had an encapsulation rate reduced to 76.2%; Comparative Example 2, lacking phytosterol esters, had insufficient membrane rigidity and high porosity, resulting in an encapsulation rate of only 68.5%; Comparative Example 3, using a single phytosterol ester to replace the composite membrane material, failed to form a closed bilayer membrane structure, and the encapsulation rate plummeted to 35.8%. This demonstrates that the precise ratio of hydrogenated lecithin, cholesterol, and phytosterol esters is crucial for forming a dense membrane layer and improving the encapsulation rate; all three are indispensable.

[0062] In Comparative Example 7, the solvent system lacked ethoxydiethylene glycol, resulting in insufficient solubility for the complex polar active ingredients and an encapsulation efficiency of 74.3%. In Comparative Example 8, the solvent ratio was unbalanced, leading to poor polarity compatibility and an encapsulation efficiency of 77.5%. Both examples demonstrate that the ternary solvent system ratio specified in this invention can provide an efficient co-solution environment for different polar active ingredients, ensuring encapsulation efficiency.

[0063] Comparative Example 4, which replaced carboxymethyl chitosan with PVP, showed a slight decrease in encapsulation efficiency (79.8%) due to weakened electrostatic stabilization. Comparative Examples 5 and 6, which lacked lipoic acid and oxalic acid respectively, still maintained an encapsulation efficiency of over 85%, indicating that stabilizers mainly affect liposome stability, while antioxidants only target and protect the active ingredient, and neither has a significant negative impact on encapsulation efficiency.

[0064] Test Example 2 Antioxidant Performance Test 1. DPPH free radical scavenging rate: Prepare a 0.1 mmol / L DPPH ethanol solution, mix 2 mL of DPPH solution with 2 mL of sample dilution buffer (sample concentration 1 mg / mL), react in the dark for 30 min, and measure the absorbance at 517 nm (A). 样品Simultaneously, 2 mL of DPPH solution + 2 mL of blank liposomes (without antioxidants and active ingredients) at the same dilution ratio served as a blank control (A). 空白对照 ), 2 mL DPPH solution + 2 mL physiological saline served as a negative control (A) 阴性对照 ), calculate the clearance rate: DPPH clearance rate (%) = [1 - (A 样品 -A 空白对照 ) / A 阴性对照 ]×100%.

[0065] 2. Lipid peroxidation inhibition rate (thiobarbituric acid reactant method, TBARS method): (1) Oxidation model: 0.1g of the composite membrane liposome of the present invention (without antioxidants and active ingredients) was added to 50mL of Tris-HCl buffer (pH 7.4) and ultrasonically dispersed for 30min to obtain liposome suspension.

[0066] (2) Construction of reaction system: Take 2 mL of liposome suspension, add 1 mL of sample diluent (sample concentration is 1 mg / mL), then add 0.5 mL of 0.2 mmol / L FeCl3 solution and 0.5 mL of 0.2 mmol / L ascorbic acid solution, and incubate at 37℃ for 2 h to induce lipid peroxidation.

[0067] (3) Color development and detection: After incubation, add 2 mL of 20% trichloroacetic acid solution and 2 mL of 0.8% thiobarbituric acid solution, heat in a boiling water bath for 15 min, cool, centrifuge at 8000 rpm for 10 min, and take the supernatant to measure the absorbance at 532 nm (A). 样品 ).

[0068] (4) Blank control (A) 空白 ): Replace the sample diluent with 1 mL of physiological saline, and perform the remaining procedures as before; negative control (A) 阴性对照 ): Replace the sample diluent with 1 mL of physiological saline, and do not add FeCl3 and ascorbic acid solution; the rest of the operation is the same.

[0069] (5) Calculate the inhibition rate: Lipid peroxidation inhibition rate (%) = [1 - (A 样品 -A 阴性对照 ) / (A 空白 -A 阴性对照 )]×100%.

[0070] The test results are shown in Table 3.

[0071] Table 3 Results of antioxidant performance test

[0072] The DPPH free radical scavenging rate in the examples was ≥92.1%, and the lipid peroxidation inhibition rate was ≥88.7%, proving that the antioxidant system of the present invention can achieve strong protection for liposomes and active ingredients.

[0073] Comparative Example 1 showed an imbalance in membrane material composition and insufficient membrane density, preventing the antioxidant from being precisely positioned at the lipid phase and membrane-water interface. DPPH scavenging rate and lipid peroxidation inhibition rate were slightly lower than in Example 1. Comparative Example 2 lacked phytosterol esters, making the membrane layer prone to oxidation and hydrolysis, hindering the antioxidant system's effectiveness. Comparative Example 3 lacked a complete membrane structure, with no effective lipid binding sites for tocopherol, resulting in a lipid peroxidation inhibition rate of only 65.2%. This indicates that a stable composite membrane structure is the carrier for the antioxidant system to function, and membrane defects directly lead to a decrease in antioxidant performance.

[0074] Comparative Example 5, lacking lipoic acid (a membrane-water interface antioxidant), could not block the transphase transport of free radicals, resulting in a sharp drop in DPPH scavenging rate to 67.5% and a lipid peroxidation inhibition rate of only 62.3%. Comparative Example 6, lacking arugula acid (an active ingredient-targeted antioxidant), had no direct protection for the core active ingredient, with a DPPH scavenging rate of 75.8% and a lipid peroxidation inhibition rate of 70.5%. Both examples demonstrate that the targeted synergistic effect of tocopherol, lipoic acid, and arugula acid is key to achieving high antioxidant activity. The absence of a single component leads to a significant reduction in antioxidant performance, which is far superior to the protective effect of traditional single antioxidants.

[0075] The DPPH scavenging rate of Comparative Example 4 (PVP replacing carboxymethyl chitosan), Comparative Example 7 (lacking ethoxydiethylene glycol), and Comparative Example 8 (unbalanced solvent ratio) remained above 90%, and the lipid peroxidation inhibition rate was above 85%, which was not significantly different from that of Example 1. This indicates that the solvent system and stabilizer have no significant regulatory effect on the antioxidant performance of liposomes.

[0076] Test Example 3 Stability Test The samples were placed in a constant temperature and humidity chamber at 45℃ and 75% relative humidity (RH) for 3 months, and their appearance (whether there was stratification, precipitation, or discoloration) was observed. The test results are shown in Table 4.

[0077] Examples 1-4, after being stored at 45°C and 75%RH for 3 months, all remained clear and homogeneous, without stratification, precipitation, or discoloration, demonstrating excellent long-term storage stability. This is attributed to the synergistic effect of multiple stabilizing mechanisms: ① Carboxymethyl chitosan forms a hydrophilic gel network on the liposome surface through electrostatic interactions and hydrogen bonds, providing steric hindrance and effectively inhibiting particle aggregation; ② The hydrogen bonding between phytosterol esters and hydrogenated lecithin enhances membrane rigidity, reduces membrane permeability, and prevents leakage of active ingredients; ③ A ternary antioxidant network protects the membrane material from oxidative hydrolysis and maintains the integrity of the membrane structure.

[0078] Slight turbidity was observed in Comparative Examples 1, 4, 7, and 8, indicating that deviations in membrane material formulation, stabilizer substitution, or improper solvent ratios can weaken physical stability to some extent, but they can still maintain a basic dispersion state. Slight stratification and precipitation were observed in Comparative Example 2, indicating that simplifying the composite membrane material to contain only hydrogenated lecithin and cholesterol reduced membrane density, leading to accelerated liposome fusion and sedimentation. Although Comparative Examples 5 and 6 lacked antioxidants, their stability and appearance were no different from the examples, indicating that antioxidants mainly affect chemical stability and have a relatively small impact on short-term physical stability. Severe stratification and significant precipitation in Comparative Example 3 indicate that a single phytosterol ester cannot form a stable liposome dispersion system, further demonstrating the necessity of the composite membrane material.

[0079] Table 4 Stability Test Results

[0080] The above detailed description is a specific description of one of the feasible embodiments of the present invention. This embodiment is not intended to limit the patent scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included within the scope of the technical solution of the present invention.

Claims

1. A liposome delivery system with high loading rate and antioxidant properties, characterized in that, By weight percentage, it comprises the following components: 4%-10% composite membrane material, 0.3%-2% carboxymethyl deacetylated chitosan, 0.1%-2% tocopheryl acetate, 0.1%-2% lipoic acid, 0.1%-2% oxalic acid, 50%-80% glycerol, 2%-10% ethoxydiethylene glycol, 2%-10% caprylic / capric triglyceride, 2%-3% pH buffer, 0.1%-10% active ingredient, and the balance being water; The composite membrane material is composed of hydrogenated lecithin, cholesterol, and phytosterol esters in a mass ratio of 1:0.3-0.5:0.4-0.

7. The mass ratio of glycerol, ethoxydiethylene glycol, and caprylic / capric triglycerides is 15-25:1.5-2.5:

1.

2. The high loading rate and antioxidant liposome delivery system according to claim 1, characterized in that, The pH buffer solution is a phosphate buffer solution or a citrate-sodium citrate buffer solution, and the active ingredient is selected from hydrophilic or lipophilic active ingredients.

3. A method for preparing a liposome delivery system with high loading rate and antioxidant properties as described in any one of claims 1-2, characterized in that, Includes the following steps: (1) The composite membrane material, tocopheryl acetate, oxalic acid and caprylic / capric triglyceride were dissolved in ethoxydiethylene glycol and stirred to obtain the oil phase; (2) Mix glycerol, carboxymethyl deacetylated chitosan, lipoic acid and water, add pH buffer, stir to obtain aqueous phase; (3) Add the oil phase to the aqueous phase, shear emulsify, homogenize, and discharge to obtain the product; When the active ingredient is a lipophilic active ingredient, the active ingredient is added in step (1); When the active ingredient is a hydrophilic active ingredient, the active ingredient is added in step (2).

4. The preparation method according to claim 3, characterized in that, The stirring temperature in steps (1) and (2) is 50-60℃, the stirring time is 20-30 min, and the stirring speed is 400-600 rpm.

5. The preparation method according to claim 3, characterized in that, In step (3), the shearing speed is 8000-12000 rpm, the shearing time is 10-15 min, the homogenization pressure is 80-120 MPa, the cycle is 3-5 times, and the discharge temperature is 20-25℃.

6. The application of a high-loading, antioxidant liposome delivery system according to any one of claims 1-2 in cosmetics, characterized in that, The dosage form of the cosmetic is selected from essential oils, eye creams, face creams, lotions, or serums.

7. The application according to claim 6, characterized in that, The cosmetic also includes cosmetically acceptable excipients selected from one or more of humectants, emulsifiers, thickeners, and preservatives.

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