Crosslinked sodium hyaluronate sustained-release acidic small-molecule active ingredient gel and preparation method thereof

Abstract

The invention relates to the technical field of sodium hyaluronate gel, and provides cross-linked sodium hyaluronate sustained-release acidic small molecule active ingredient gel and a preparation method of the cross-linked sodium hyaluronate sustained-release acidic small molecule active ingredient gel. The carboxylic acid group of the hyaluronic acid and the carboxylic acid group of the acidic small molecule respectively form a stable ion adsorption effect with the alkaline intermediary substance, so that the retention time of the hyaluronic acid in the body is prolonged, and the acidic small molecule component is controllably and slowly released. The preparation method is high in operability, simple and cost-saving.

Description

Technical Field

[0001] This invention relates to the field of sodium hyaluronate gel technology, and more specifically, to a cross-linked sodium hyaluronate sustained-release acidic small molecule active ingredient gel and its preparation method. Background Technology

[0002] Sodium hyaluronate (HA) is a natural polysaccharide, first isolated from bovine vitreous humor by Meyer et al. in 1934. It is composed of D-glucuronic acid and N-acetyl-D-glucosamine linked alternately by β-1,3 and β-1,4-glycosidic bonds. It is widely distributed in the cytoplasm and intercellular matrix of the body, playing a lubricating and nourishing role for the cells and organelles contained within. HA molecules form an interactive network structure through non-covalent interactions, with chains intertwined to form a complex network. The HA molecular chain contains a large number of hydroxyl groups, which can adsorb hundreds of times their own weight in water, achieving a moisturizing effect. However, due to the relatively loose intermolecular structure of HA, it is easily degraded and destroyed, resulting in a short duration of its moisturizing function, which greatly limits its application in facial fillers.

[0003] Subsequent studies revealed that the loose structure of HA molecules can be reinforced through cross-linking. This reinforcement significantly improves the physical support of the HA gel, enhancing its stability and extending its survival time in vivo. The cross-linking mechanism of HA molecules involves the activation of groups on the cross-linking agent, which then covalently link with free carboxyl or hydroxyl groups on the HA molecule, forming ether bonds. These stable bonds transform the HA molecule from its original loose and disordered state into a complex and stable network. Once the free carboxyl and hydroxyl groups on the HA molecule are bound, the cleavage efficiency of hyaluronidase, which specifically recognizes the cleavage sites, decreases, thereby prolonging the survival time of the cross-linked sodium hyaluronate gel in vivo.

[0004] To improve stability, existing technologies typically employ chemical cross-linking agents (such as BDDE) to cross-link and reinforce HA. However, BDDE, as an epoxy compound, has significant drawbacks: 1. Cytotoxicity risk: Residual BDDE is difficult to completely metabolize, potentially triggering postoperative adverse reactions such as inflammation and granulomas; 2. Process complexity: Controlling residual amounts requires additional purification steps, increasing production costs; 3. Functional limitation: Traditional cross-linked gels only provide physical filling and lack synergistic activity; 4. Recent research has focused on combining functional components (such as collagen) with HA to stimulate collagen regeneration.

[0005] However, acidic small molecule active ingredients (such as chondroitin sulfate, acetylcysteine, and tranexamic acid) have unique value in cosmetic repair: 1. Chondroitin sulfate: promotes tissue repair and enhances skin elasticity; 2. Acetylcysteine: has antioxidant properties and inhibits melanin production; 3. Tranexamic acid: reduces pigmentation and brightens skin tone.

[0006] However, there are two major bottlenecks to directly adding such ingredients to gels: 1. Rapid release: Due to their small molecular weight and high water solubility, they diffuse rapidly in the body and cannot exert a long-lasting effect; 2. Low encapsulation efficiency: The carboxyl groups of acidic small molecules and the carboxyl groups of HA are similar and repulsive, making it difficult to achieve stable binding through conventional mixing.

[0007] Existing technologies attempt to load active ingredients through physical mixing or covalent coupling, but the former results in poor sustained-release effects, while the latter may damage the activity of small molecules and involves complex processes. Therefore, there is an urgent need to develop a non-covalent binding technology that can achieve efficient loading and controlled sustained release of acidic small molecules while avoiding toxic cross-linking agents. Summary of the Invention

[0008] To overcome the shortcomings of the prior art, the present invention provides a method for preparing a cross-linked sodium hyaluronate sustained-release acidic small molecule active ingredient gel, comprising the following steps: S1. Add an alkaline intermediate to (crosslinked) sodium hyaluronate, stir initially, and then place it in a high-pressure homogenizer for homogenization to obtain a homogenized product. The crosslinked sodium hyaluronate is sodium hyaluronate crosslinked with a terminal epoxy crosslinking agent. S2. Add physiological saline containing chondroitin sulfate, acetylcysteine, and tranexamic acid to the homogenized product obtained in step S1 to obtain a mixture. Place the mixture in a constant temperature shaker for shaking treatment, and then centrifuge to obtain a cross-linked sodium hyaluronate sustained-release acidic small molecule active ingredient gel. Compared with the prior art, the preparation method of the present invention introduces alkaline intermediary substances (such as lysine, arginine, etc.) to efficiently construct an ion adsorption network under high pressure homogenization and low temperature conditions: on the one hand, the alkaline groups are used to combine with the carboxylic acid groups of sodium hyaluronate to neutralize charge repulsion; on the other hand, the acidic small molecule active ingredients such as chondroitin sulfate, acetylcysteine, and tranexamic acid are strongly anchored through electrostatic interaction, achieving a triple breakthrough: 1. Avoiding the toxicity of traditional BDDE cross-linking agents and significantly reducing biosafety risks; 2. Overcoming the bottleneck of charge repulsion between acidic small molecules and gel matrix, significantly improving encapsulation stability; 3. Relying on non-covalent ionic bonds to achieve controllable sustained release and prolong the duration of efficacy of active ingredients.

[0009] In one possible implementation, in step S1, the particle size D50 of the cross-linked sodium hyaluronate is 300-500µm.

[0010] In one possible implementation, in step S1, the content of sodium hyaluronate in the cross-linked sodium hyaluronate is 18-24 mg / g, and the viscosity is 6300-6500.

[0011] Compared with existing technologies, this invention uses sodium hyaluronate with the above parameters. By precisely matching the carrier particle size and gel network density, it ensures a high specific surface area to fully expose carboxylic acid groups while maintaining the mechanical stability of the gel skeleton. This provides uniform and efficient charge binding sites for alkaline mediators, promoting the construction of ion adsorption networks. It also avoids the decrease in loading capacity caused by excessively large particle size or insufficient content, or the deterioration of gel flowability caused by excessively small particle size or excessive content, ensuring the stability and controllability of subsequent homogenization and adsorption processes.

[0012] In one possible implementation, in step S1, the alkaline intermediary is selected from one of L-lysine, poly-L-lysine, L-arginine, and poly-L-arginine.

[0013] In one possible implementation, the molar ratio of L-lysine to cross-linked sodium hyaluronate is (5-25):100; The molar ratio of poly-L-lysine to cross-linked sodium hyaluronate is (1-3):20, and the molecular weight of poly-L-lysine is 2000-5000 Da. The molar ratio of L-lysine to cross-linked sodium hyaluronate is (1-3):20; The molar ratio of poly-L-arginine to cross-linked sodium hyaluronate is (1-3):20, and the molecular weight of poly-L-arginine is 1500-2000 Da.

[0014] Compared with existing technologies, this invention achieves triple optimization through precise matching of the spatial arrangement and charge density of basic groups (amino / guanidinium groups): 1. Biocompatibility: Natural amino acids and their polymers are non-cytotoxic, avoiding the residual risks of traditional chemical cross-linking agents; 2. Charge compatibility: Strong basic groups efficiently neutralize the negative charge of the carboxylic acid in sodium hyaluronate, overcoming the bottleneck of electrostatic repulsion of acidic small molecules; 3. Structural controllability: Monomers provide flexible adsorption sites, and polymers construct multivalent cross-linked networks to adapt to different sustained-release strength requirements. In other words, this invention ensures stable anchoring of ionic bonds at the molecular level, laying the chemical foundation for efficient encapsulation and long-lasting sustained release.

[0015] In one possible implementation, the homogenization parameters in step S1 are as follows: rotation speed of 10000-14000 rpm, frequency of 40-60 Hz, and temperature of 0-10 ℃.

[0016] Compared with existing technologies, this invention protects the molecular structure integrity while fully breaking down gel aggregates by synergistically controlling shear force intensity and low-temperature environment. Specifically: 1. High-frequency shear force ensures uniform assembly of alkaline intermediary and sodium hyaluronate, forming a dense ion adsorption network; 2. Low-temperature environment inhibits molecular thermal motion, maintains electrostatic pre-binding stability, and avoids loss of active sites; 3. Parameter window matches industrial equipment standards, ensuring process reproducibility and feasibility for large-scale production.

[0017] In one possible implementation, in step S2, the volume ratio of the homogenized product to physiological saline containing chondroitin sulfate, acetylcysteine, and tranexamic acid is 1:1, and the molar ratio of chondroitin sulfate to cross-linked sodium hyaluronate in the physiological saline is (8-12):100, the molar ratio of acetylcysteine ​​to cross-linked sodium hyaluronate is (8-12):100, and the molar ratio of tranexamic acid to cross-linked sodium hyaluronate is (8-12):100.

[0018] Compared with existing technologies, the core advantages of this invention, which limits the volume ratio to 1:1 and the molar ratio to (8-12):100, lie in achieving triple synergistic optimization through precise balancing of the solid-liquid interface and molecular charge ratio. Specifically: 1. Phase compatibility: Equal volume mixing ensures uniform swelling of the gel network, avoiding uneven encapsulation caused by local concentration gradients; 2. Charge saturation matching: The molar amount of active ingredients matches the capacity of the carboxylic acid groups of sodium hyaluronate, maximizing ionic bond binding efficiency; 3. Multi-component synergy: Simultaneously regulating the competitive adsorption of three acidic small molecules avoids mutual repulsion of active ingredients.

[0019] In one possible implementation, the parameters for the oscillation process in step S2 are as follows: temperature 0-10 ℃, rotation speed 200-300 rpm, and time 10-14 h.

[0020] Compared with existing technologies, the core advantage of this invention in limiting oscillation parameters lies in achieving a triple precision balance through synergistic regulation of molecular diffusion dynamics and low-temperature protection effects. Specifically: 1. Low-temperature suppression of thermal disturbances: ensuring stable formation of ionic bonds and avoiding degradation of acidic small molecules; 2. Mild shear force driving: promoting deep penetration of active ingredients into the gel network and eliminating encapsulation blind zones; 3. Full coverage of the time window: ensuring that multiple components reach adsorption equilibrium simultaneously and establishing a uniform sustained-release system.

[0021] In one possible implementation, the centrifugation parameters in step S2 are as follows: rotation speed of 4000-6000 rpm and time of 3-6 min.

[0022] The second objective of this invention is to provide a sodium hyaluronate sustained-release acidic small molecule active ingredient gel, wherein the content of chondroitin sulfate sodium coating is 2.0-3.0 mg / g, the content of acetylcysteine ​​coating is 0.65-1.0 mg / g, and the content of tranexamic acid coating is 0.63-0.94 mg / g.

[0023] This invention achieves three core breakthroughs simultaneously by precisely limiting the loading concentrations of chondroitin sulfate sodium (2.0-3.0 mg / g), acetylcysteine ​​(0.65-1.0 mg / g), and tranexamic acid (0.63-0.94 mg / g) on ​​an ion-anchoring network constructed with alkaline mediators: precisely matching the efficacy thresholds of each component to ensure long-term synergistic release of repair, antioxidant, and melanin-reducing effects; strictly adhering to the charge load limit of hyaluronic acid gel to avoid structural collapse and eliminate the risk of burst release; and optimizing the total amount of active ingredients per unit dose to maintain high bioavailability while avoiding metabolic burden. Ultimately, by achieving a golden balance of "drug loading - sustained release - safety," this invention lays the industrial foundation for multi-effect regenerative medicine products. Detailed Implementation

[0024] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described in detail below. It should be noted that the following embodiments are only used to illustrate the implementation methods and typical parameters of the present invention, and are not intended to limit the parameter range described in the present invention. Reasonable variations derived therefrom are still within the protection scope of the claims of the present invention.

[0025] It should be noted that the endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0026] Unless otherwise defined, all terms, symbols, and other scientific terms used herein are intended to have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In some instances, terms having a conventional meaning are defined herein for clarification or ease of reference, and such definitions should not be construed as indicating a significant difference from conventional understanding in the art. The technical methods described or referenced herein are generally well understood by those skilled in the art and employed by conventional methods. Unless otherwise stated, the use of commercially available kits, reagents, and instruments shall be performed according to the manufacturer's instructions and parameters.

[0027] Example 1 Take 100g of cross-linked sodium hyaluronate with a content of 20 mg / g and an average particle size D50 of 400 µm, and add it to L-lysine solution in proportions of 0%, 5%, 10%, 15%, 20%, and 25% (monomer molar ratio), and stir initially. The homogenized product was obtained by homogenizing the product using a high-pressure homogenizer at 4°C, 50Hz, and 12000 rpm. The homogenized products obtained separately were added to physiological saline containing chondroitin sulfate, acetylcysteine ​​and tranexamic acid at a ratio of 1:1 (v / v). The molar ratio of chondroitin sulfate to cross-linked sodium hyaluronate in the physiological saline was 10:100, the molar ratio of acetylcysteine ​​to cross-linked sodium hyaluronate was 10:100, and the molar ratio of tranexamic acid to cross-linked sodium hyaluronate was 10:100.

[0028] Then it was placed in a constant temperature shaker at 4℃ and shaken at 200 rpm for 12 h. The gel and buffer were then obtained by centrifugation at 5000 rpm for 5 min. The contents of sodium hyaluronate, chondroitin sulfate, acetylcysteine, and tranexamic acid in the gel and supernatant were detected by high performance liquid chromatography (HPLC). The specific procedures were as follows: Take 20g of gel, add physiological saline at a ratio of 1:1 (v / v), place on a shaker at 4 degrees Celsius, shake at 200 rpm, determine the content of chondroitin sulfate, acetylcysteine, and tranexamic acid in the supernatant, and calculate the sustained-release half-life of the above components coated in the gel.

[0029] The results of testing, including the content of active ingredients and the sustained-release half-life of the gel coating prepared in this embodiment, are shown in Table 1. Example 2 1) Take 100g of cross-linked sodium hyaluronate with a content of 20 mg / g and an average particle size D50 of 400 µm, add it to L-lysine solution at a ratio of 10% (monomer molar ratio), and stir initially. 2) Homogenize the product using a high-pressure homogenizer at 4°C, 50Hz, and 12000 rpm. 3) The homogenized product was added to physiological saline containing sodium chondroitin sulfate, acetylcysteine, and tranexamic acid at a ratio of 1:1 (v / v). The molar ratios of sodium chondroitin sulfate, acetylcysteine, tranexamic acid, and sodium hyaluronate in the physiological saline were 4%, 6%, 8%, 10%, 12%, and 16%, respectively. The mixture was placed in a constant temperature shaker at 4°C and shaken at 200 rpm for 12 h. The gel and buffer were obtained by centrifugation at 5000 rpm for 5 min. 4) The contents of sodium hyaluronate, chondroitin sulfate, acetylcysteine, and tranexamic acid in the gel and supernatant were detected by high performance liquid chromatography (HPLC). The specific procedure was as follows: Take 20g of gel, add physiological saline at a ratio of 1:1 (v / v), place on a shaker at 4 degrees Celsius and shake at 200 rpm, determine the content of chondroitin sulfate, acetylcysteine ​​and tranexamic acid in the supernatant, and calculate the sustained-release half-life of the above components coated in the gel.

[0030] The results of testing, including the content of active ingredients and the sustained-release half-life of the gel coating prepared in this embodiment, are shown in Table 2. Example 3 Take 100g of cross-linked sodium hyaluronate with a content of 20 mg / g and an average particle size D50 of 400 µm, add it to poly-L-lysine solution at a ratio of 0%, 5%, 10%, 15%, 20%, and 25% (monomer molar ratio), and stir initially. The homogenized product was obtained by homogenizing the product using a high-pressure homogenizer at 4°C, 50Hz, and 12000 rpm. The homogenized products were added to physiological saline containing chondroitin sulfate, acetylcysteine ​​and tranexamic acid at a ratio of 1:1 (v / v), with the molar ratio of chondroitin sulfate, acetylcysteine ​​and tranexamic acid to sodium hyaluronate in the physiological saline being 1:10. The mixture was then placed in a constant temperature shaker at 4°C and shaken at 200 rpm for 12 h. The gel and buffer were then obtained by centrifugation at 5000 rpm for 5 min. The contents of sodium hyaluronate, chondroitin sulfate, acetylcysteine, and tranexamic acid in the gel and supernatant were detected by high performance liquid chromatography (HPLC). The specific procedures were as follows: Take 20g of gel, add physiological saline at a ratio of 1:1 (v / v), place on a shaker at 4 degrees Celsius, shake at 200 rpm, determine the content of chondroitin sulfate, acetylcysteine, and tranexamic acid in the supernatant, and calculate the sustained-release half-life of the above components coated in the gel.

[0031] The results of testing, including the content of active ingredients and the sustained-release half-life of the gel coating prepared in this embodiment, are shown in Table 3. Example 4 1) Take 100g of cross-linked sodium hyaluronate with a content of 20 mg / g and an average particle size D50 of 400 µm, add it to poly-L-lysine solution at a ratio of 10% (monomer molar ratio), and stir initially. 2) Homogenize the product using a high-pressure homogenizer at 4°C, 50Hz, and 12000 rpm. 3) The homogenized product was added to physiological saline containing sodium chondroitin sulfate, acetylcysteine, and tranexamic acid at a ratio of 1:1 (v / v). The molar ratios of sodium chondroitin sulfate, acetylcysteine, tranexamic acid, and sodium hyaluronate in the physiological saline were 4%, 6%, 8%, 10%, 12%, and 16%, respectively. The mixture was placed in a constant temperature shaker at 4°C and shaken at 200 rpm for 12 h. The gel and buffer were obtained by centrifugation at 5000 rpm for 5 min. 4) The contents of sodium hyaluronate, chondroitin sulfate, acetylcysteine, and tranexamic acid in the gel and supernatant were detected by high performance liquid chromatography (HPLC). The specific procedure was as follows: Take 20g of gel, add physiological saline at a ratio of 1:1 (v / v), place on a shaker at 4 degrees Celsius and shake at 200 rpm, determine the content of chondroitin sulfate, acetylcysteine ​​and tranexamic acid in the supernatant, and calculate the sustained-release half-life of the above components coated in the gel.

[0032] The results of testing, including the content of active ingredients and the sustained-release half-life of the gel coating prepared in this embodiment, are shown in Table 4. Example 5 1) Take 100g of cross-linked sodium hyaluronate with a content of 20 mg / g and an average particle size D50 of 400 µm, add it to L-arginine solution in proportions of 0%, 5%, 10%, 15%, 20%, and 25% (monomer molar ratio), and stir initially. 2) Homogenize the product by using a high-pressure homogenizer at 4℃, 50Hz, and 12000 rpm. 3) The homogenized products obtained separately were added to physiological saline containing chondroitin sulfate, acetylcysteine ​​and tranexamic acid at a ratio of 1:1 (v / v). The molar ratio of chondroitin sulfate, acetylcysteine ​​and tranexamic acid to sodium hyaluronate in the physiological saline was 1:10. The mixture was then placed in a constant temperature shaker at 4°C and shaken at 200 rpm for 12 h. The gel and buffer were then obtained by centrifugation at 5000 rpm for 5 min. 4) The contents of sodium hyaluronate, chondroitin sulfate, acetylcysteine, and tranexamic acid in the gel and supernatant were detected by high performance liquid chromatography (HPLC). The specific procedures were as follows: Take 20g of gel, add physiological saline at a ratio of 1:1 (v / v), place on a shaker at 4 degrees Celsius, shake at 200 rpm, determine the content of chondroitin sulfate, acetylcysteine, and tranexamic acid in the supernatant, and calculate the sustained-release half-life of the above components coated in the gel.

[0033] The results of testing, including the content of active ingredients and the sustained-release half-life of the gel coating prepared in this embodiment, are shown in Table 5. Example 6 1) Take 100g of cross-linked sodium hyaluronate with a content of 20 mg / g and an average particle size D50 of 400 µm, add it to L-arginine solution at a ratio of 10% (monomer molar ratio), and stir initially. 2) Homogenize the product using a high-pressure homogenizer at 4°C, 50Hz, and 12000 rpm. 3) The homogenized product was added to physiological saline containing sodium chondroitin sulfate, acetylcysteine, and tranexamic acid at a ratio of 1:1 (v / v). The molar ratios of sodium chondroitin sulfate, acetylcysteine, tranexamic acid, and sodium hyaluronate in the physiological saline were 4%, 6%, 8%, 10%, 12%, and 16%, respectively. The mixture was placed in a constant temperature shaker at 4°C and shaken at 200 rpm for 12 h. The gel and buffer were obtained by centrifugation at 5000 rpm for 5 min. 4) The contents of sodium hyaluronate, chondroitin sulfate, acetylcysteine, and tranexamic acid in the gel and supernatant were detected by high performance liquid chromatography (HPLC). The specific procedure was as follows: Take 20g of gel, add physiological saline at a ratio of 1:1 (v / v), place on a shaker at 4 degrees Celsius and shake at 200 rpm, determine the content of chondroitin sulfate, acetylcysteine ​​and tranexamic acid in the supernatant, and calculate the sustained-release half-life of the above components coated in the gel.

[0034] The results of testing, including the content of active ingredients and the sustained-release half-life of the gel coating prepared in this embodiment, are shown in Table 6. Example 7 1) Take 100g of cross-linked sodium hyaluronate with a content of 20 mg / g and an average particle size D50 of 400 µm, and add it to poly-L-arginine solution in proportions of 0%, 5%, 10%, 15%, 20%, and 25% (monomer molar ratio), and stir initially. 2) Homogenize the product by using a high-pressure homogenizer at 4℃, 50Hz, and 12000 rpm. 3) The homogenized products obtained separately were added to physiological saline containing chondroitin sulfate, acetylcysteine ​​and tranexamic acid at a ratio of 1:1 (v / v). The molar ratio of chondroitin sulfate, acetylcysteine ​​and tranexamic acid to sodium hyaluronate in the physiological saline was 1:10. The mixture was then placed in a constant temperature shaker at 4°C and shaken at 200 rpm for 12 h. The gel and buffer were then obtained by centrifugation at 5000 rpm for 5 min. 4) The contents of sodium hyaluronate, chondroitin sulfate, acetylcysteine, and tranexamic acid in the gel and supernatant were detected by high performance liquid chromatography (HPLC). The specific procedures were as follows: Take 20g of gel, add physiological saline at a ratio of 1:1 (v / v), place on a shaker at 4 degrees Celsius, shake at 200 rpm, determine the content of chondroitin sulfate, acetylcysteine, and tranexamic acid in the supernatant, and calculate the sustained-release half-life of the above components coated in the gel.

[0035] The results of testing, including the content of active ingredients and the sustained-release half-life of the gel coating prepared in this embodiment, are shown in Table 7. Example 8 1) Take 100g of cross-linked sodium hyaluronate with a content of 20 mg / g and an average particle size D50 of 400 µm, add it to poly-L-arginine solution at a ratio of 10% (monomer molar ratio), and stir initially. 2) Homogenize the product using a high-pressure homogenizer at 4°C, 50Hz, and 12000 rpm. 3) The homogenized product was added to physiological saline containing sodium chondroitin sulfate, acetylcysteine, and tranexamic acid at a ratio of 1:1 (v / v). The molar ratios of sodium chondroitin sulfate, acetylcysteine, tranexamic acid, and sodium hyaluronate in the physiological saline were 4%, 6%, 8%, 10%, 12%, and 16%, respectively. The mixture was placed in a constant temperature shaker at 4°C and shaken at 200 rpm for 12 h. The gel and buffer were obtained by centrifugation at 5000 rpm for 5 min. 4) The contents of sodium hyaluronate, chondroitin sulfate, acetylcysteine, and tranexamic acid in the gel and supernatant were detected by high performance liquid chromatography (HPLC). The specific procedure was as follows: Take 20g of gel, add physiological saline at a ratio of 1:1 (v / v), place on a shaker at 4 degrees Celsius and shake at 200 rpm, determine the content of chondroitin sulfate, acetylcysteine ​​and tranexamic acid in the supernatant, and calculate the sustained-release half-life of the above components coated in the gel.

[0036] The results of testing, including the content of active ingredients and the sustained-release half-life of the gel coating prepared in this embodiment, are shown in Table 8. The results show that the preparation method of this invention, by introducing alkaline mediators (such as lysine and arginine), efficiently constructs an ion adsorption network under high-pressure homogenization and low-temperature conditions. The resulting hyaluronic acid gel is coated with acidic small-molecule active ingredients. The carboxylic acid groups of hyaluronic acid and the carboxylic acid groups of the acidic small molecules form stable ion adsorption relationships with the alkaline mediators, respectively, prolonging the retention time of hyaluronic acid in vivo and controlling the slow release of acidic small-molecule components. This preparation method is highly operable, simple, and cost-effective.

[0037] While the disclosure is as stated above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the protection scope of this invention.

Claims

1. A method for preparing a cross-linked sodium hyaluronate sustained-release acidic small molecule active ingredient gel, characterized by, The method comprises the following steps: S1, adding an alkaline intermediate substance to cross-linked sodium hyaluronate, and then stirring to obtain a homogeneous product, wherein the cross-linked sodium hyaluronate is sodium hyaluronate cross-linked by a terminal epoxy group cross-linking agent; S2, adding physiological saline containing chondroitin sulfate, acetylcysteine and tranexamic acid to the homogeneous product obtained in step S1 to obtain a mixture, and then performing centrifugal treatment on the mixture after oscillation treatment to obtain a cross-linked sodium hyaluronate sustained-release acidic small molecule active ingredient gel.

2. The production method according to claim 1, wherein In step S1, the particle size D50 of the cross-linked sodium hyaluronate is 300-500 µm.

3. The production method according to claim 1, wherein In step S1, the content of sodium hyaluronate in the cross-linked sodium hyaluronate is 18-24 mg / g, and the viscosity is 6300-6500.

4. The production method according to claim 1, wherein In step S1, the alkaline intermediate substance is selected from one of L-lysine, poly-L-lysine, L-arginine and poly-L-arginine.

5. The production method according to claim 4, wherein The molar ratio of the L-lysine to the cross-linked sodium hyaluronate is (5-25):

100. The molar ratio of the poly-L-lysine to the cross-linked sodium hyaluronate is (1-3):20, and the molecular weight of the poly-L-lysine is 2000-5000 Da. The molar ratio of the L-arginine to the cross-linked sodium hyaluronate is (1-3):

20. The molar ratio of the poly-L-arginine to the cross-linked sodium hyaluronate is (1-3):20, and the molecular weight of the poly-L-arginine is 1500-2000 Da.

6. The production method according to claim 1, wherein In step S1, the parameters of the homogenization treatment are as follows: the rotation speed is 10000-14000 rpm, the frequency is 40-60 Hz, and the temperature is 0-10 ℃.

7. The production method according to claim 1, wherein In step S2, the volume ratio of the homogeneous product to the physiological saline containing chondroitin sulfate, acetylcysteine and tranexamic acid is 1:1, and in the physiological saline, the molar ratio of chondroitin sulfate to cross-linked sodium hyaluronate is (8-12):100, the molar ratio of acetylcysteine to cross-linked sodium hyaluronate is (8-12):100, and the molar ratio of tranexamic acid to cross-linked sodium hyaluronate is (8-12):

100.

8. The production method according to claim 1, wherein In step S2, the parameters of the oscillation treatment are as follows: the temperature is 0-10 ℃, the rotation speed is 200-300 rpm, and the time is 10-14 h.

9. The production method according to claim 1, wherein In step S2, the parameters of the centrifugal treatment are as follows: the rotation speed is 4000-6000 rpm, and the time is 3-6 min.

10. A cross-linked sodium hyaluronate gel for sustained release of an acidic small molecule active principle, prepared according to the process of any one of claims 1 to 9, characterized in that, In the cross-linked sodium hyaluronate sustained-release acidic small molecule active ingredient gel, the content of coated chondroitin sulfate sodium is 2.0-3.0 mg / g, the content of coated acetylcysteine is 0.65-1.0 mg / g, and the content of coated tranexamic acid is 0.63-0.94 mg / g.

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