Elagic acid composite solid dispersion and preparation method thereof

Abstract

The invention discloses an ellagic acid composite solid dispersion and a preparation method thereof. The preparation method comprises the following steps: S1, respectively preparing a fucoidin aqueous solution and an ellagic acid ethanol suspension; s2, mixing the two solutions to obtain a mixed solution; s3, adding the modified polysorbate 20 and the chitosan-CPP compound, and performing ultrasonic stirring; s4, ball milling; and S5, carrying out reduced pressure rotary evaporation to remove the solvent, drying, crushing, and sieving with a 100-mesh sieve to obtain the product. Ternary synergistic compounding is formed through the fucoidin-modified polysorbate 20-chitosan-CPP compound, a multi-dimensional molecular interaction network is constructed, and the effect of remarkably improving the water solubility and dispersion stability of ellagic acid is achieved; wherein xylooligosaccharide branched chains of the modified polysorbate 20, hydroxyl groups of the fucoidin and phosphate groups of the chitosan-CPP compound form a multi-point hydrogen bond cross-linked structure through hydrogen bonds, and the hydrophobic association effect and lattice stacking among ellagic acid molecules are broken through the steric hindrance effect.

Description

Technical Field

[0001] This invention belongs to the field of functionalized natural product technology, specifically relating to an ellagic acid complex solid dispersion and its preparation method. Background Technology

[0002] Ellagic acid, a natural polyphenol compound, is widely found in plants such as pomegranate and raspberry, and possesses significant antioxidant, anti-inflammatory, antitumor, and cardiovascular protective activities. It exerts its pharmacological effects through mechanisms such as scavenging free radicals, regulating apoptosis signaling pathways, and inhibiting tumor angiogenesis, showing great promise in the development of functional foods and antitumor drugs. However, the presence of a polyhydroxy lactone ring in its molecular structure results in extremely low water solubility and low oral bioavailability. It is also prone to pH-dependent degradation in the gastrointestinal tract and has poor cell membrane permeability, severely limiting its clinical efficacy. While some studies have attempted to improve this, several challenges remain. For example, liposome preparation suffers from low drug loading, complex preparation processes, and high costs for large-scale production; cyclodextrin inclusion complexes only offer limited improvement in solubility and have insufficient effect on promoting intestinal absorption; and binary solid dispersions often use carriers (such as PVP and PEG) which suffer from burst release effects and poor physical stability.

[0003] Therefore, there is an urgent need to propose a widely applicable method to improve the absorption and utilization of ellagic acid. Summary of the Invention

[0004] Technical Problem to be Solved: To address the aforementioned problems, the present invention aims to provide an ellagic acid composite solid dispersion and its preparation method. A ternary synergistic composite is formed by a fucoidan-modified polysorbate 20-chitosan-CPP complex, constructing a multi-dimensional molecular interaction network to significantly improve the water solubility and dispersion stability of ellagic acid. Specifically, the xylooligosaccharide branches of modified polysorbate 20 form a multi-point hydrogen bond cross-linking structure with the hydroxyl groups of fucoidan and the phosphate groups of the chitosan-CPP complex through hydrogen bonds, breaking the hydrophobic association and lattice stacking between ellagic acid molecules through steric hindrance. Simultaneously, the optimized HLB value of modified polysorbate 20 is used to adapt to the water-ethanol mixture system, further enhancing the dispersion compatibility of ellagic acid and improving its water solubility limitation at the molecular level.

[0005] Technical solution: A method for preparing ellagic acid composite solid dispersion, comprising the following steps: S1. Dissolve fucoidan in deionized water to obtain a fucoidan aqueous solution; dissolve ellagic acid in an ethanol aqueous solution to obtain an ellagic acid suspension; S2. Mix the fucoidan aqueous solution with the ellagic acid suspension and stir until homogeneous to obtain a mixture; S3. Add modified polysorbate 20, then add chitosan-CPP complex, and stir for 2-5 hours at a temperature of 30-50℃ and an ultrasonic power of 100-280W. S4. Transfer to a ball mill and ball mill at 100-240 rpm for 2.5-6 hours to obtain a homogeneous mixed solution; S5. Remove the solvent from the mixed solution by rotary evaporation under reduced pressure, transfer it to a drying oven for drying, pulverize it, and pass it through a 100-mesh sieve to obtain ellagic acid composite solid dispersion.

[0006] Furthermore, the fucoidan described in S1 is obtained from seaweed through water extraction and purification, and satisfies the following conditions: (1) It is mainly composed of fucose and small amounts of galactose, glucosamine and galactosamine; (2) The fucoidan chain is mainly composed of the [→3-α-l-Fucp2S,4S-1→3-α-l-Fucp-1→3-α-l-Fucp2S-1→3-α-l-Fucp2S-1→] domain; (3) The average molecular weight is 25-40 kDa.

[0007] Furthermore, the concentration of the fucoidan aqueous solution in S1 is 0.1 mg / mL to 2.5 mg / mL; and the concentration of the ellagic acid suspension is 0.1 mg / mL to 1 mg / mL.

[0008] Furthermore, the volume fraction of ethanol in the ethanol-water solution is 30%-70%.

[0009] Furthermore, the mass ratio of fucoidan to ellagic acid in the mixture described in S2 is (0.2-4):1.

[0010] Furthermore, the amount of modified polysorbate 20 added in S3 is 0.05%-0.2% of the mass of ellagic acid; the amount of chitosan-CPP complex added is 0.1%-0.3% of the mass of ellagic acid.

[0011] Furthermore, the preparation method of the modified polysorbate 20 described in S3 is as follows: Step 1. Add polysorbate 20 and xylooligosaccharide to a reaction vessel, add sodium hydroxide as a catalyst (the amount is 0.5%-1% of the total mass of the reactants), under nitrogen protection, control the reaction temperature at 80-100℃, the stirring speed at 200-300 rpm, and react for 4-6 hours to achieve xylooligosaccharide grafting and obtain the grafted product. Step 2. Cool to 40-50℃, introduce hydrogen gas (pressure 0.3-0.5MPa), add palladium on carbon catalyst, and perform hydrogenation reaction for 2-3 hours, controlling the degree of hydrogenation at 12%-20%; Step 3. Filter to remove the catalyst, and remove residual moisture by vacuum distillation to obtain modified polysorbate 20.

[0012] Furthermore, the mass ratio of polysorbate 20 to xylooligosaccharide in step 1 is 1:(0.3-0.8).

[0013] Furthermore, the xylobiose + xylotriose content in the xylooligosaccharide is ≥90%.

[0014] Furthermore, the amount of palladium catalyst added is 0.1%-0.3% of the mass of the grafted product.

[0015] Furthermore, the vacuum distillation conditions are: temperature 50-60℃, pressure -0.08~-0.09MPa.

[0016] Furthermore, the preparation method of the chitosan-CPP complex described in S3 is as follows: (1) Dissolve food-grade chitosan and casein phosphopeptide (CPP) in a 2% (v / v) dilute acetic acid aqueous solution at a mass ratio of 1:(0.6-1.5) to obtain a mixed solution with a total concentration of 5-12 mg / mL. (2) Adjust the pH to 7.2-7.5 with 0.1 mol / L sodium hydroxide solution, add alkaline protease, and carry out the enzymatic hydrolysis reaction for 1.5-2.5 h at a temperature of 48-55℃; (3) Heat to 80-85℃ and keep warm for 15-20 min to inactivate the enzyme. After cooling, centrifuge to collect the supernatant and freeze dry to obtain chitosan-CPP complex.

[0017] Furthermore, the degree of deacetylation of the food-grade chitosan is ≥85%.

[0018] Furthermore, the amount of alkaline protease added is 0.06%-0.12% of the mass of the mixed solution.

[0019] Furthermore, the centrifugation conditions were 10,000-12,000 rpm for 10-15 min.

[0020] Furthermore, the freeze-drying conditions are: temperature -40~-50℃, time 12-16h.

[0021] Furthermore, the reduced pressure rotary evaporation temperature described in S5 is 40-50℃; the drying temperature is 40-60℃; and the drying time is 3-11h.

[0022] The present invention also provides an ellagic acid composite solid dispersion prepared by the above preparation method. Beneficial effects

[0023] 1. This invention utilizes a ternary synergistic complex formed by fucoidan-modified polysorbate 20-chitosan-CPP to construct a multi-dimensional molecular interaction network, thereby significantly improving the water solubility and dispersion stability of ellagic acid. Specifically, the xylooligosaccharide branches of modified polysorbate 20 form a multi-point hydrogen bond cross-linking structure with the hydroxyl groups of fucoidan and the phosphate groups of the chitosan-CPP complex through hydrogen bonds, breaking the hydrophobic association and lattice stacking between ellagic acid molecules through steric hindrance. Simultaneously, the optimized HLB value of modified polysorbate 20 is adapted to the water-ethanol mixture system, further enhancing the dispersion compatibility of ellagic acid and improving its water solubility limitation at the molecular level.

[0024] 2. This invention utilizes a combination of amorphization regulation and molecular encapsulation to reduce the crystallinity of ellagic acid and inhibit its structural degradation in the gastrointestinal environment. The coupling effect of ultrasonic cavitation and ball milling mechanical force induces lattice distortion and gradual disintegration of ellagic acid crystals. The dense polymer network formed by fucoidan and chitosan-CPP complex can encapsulate amorphous ellagic acid molecules, hindering their migration and recrystallization, thus maintaining their amorphous stability. Furthermore, it isolates ellagic acid from contact with enzymes such as proteases and esterases in gastrointestinal fluids, while buffering the damage to the lactone ring structure of ellagic acid caused by gastrointestinal pH fluctuations, significantly reducing its pH-dependent degradation rate and ensuring the structural integrity of ellagic acid in digestive fluids.

[0025] 3. The linear long-chain structure of fucoidan in this invention exhibits excellent intestinal mucosal adhesion properties, which can prolong the retention time of the ellagic acid complex dispersion in the intestine and increase the absorption window. The CPP component in the chitosan-CPP complex can specifically bind to calcium-sensitive receptors on the surface of intestinal epithelial cells, mediating the reversible opening of tight junctions between cells and promoting the transcellular transport of ellagic acid. At the same time, the positive charge of chitosan molecules can form electrostatic adsorption with the negatively charged groups of the intestinal mucosa, further enhancing the contact efficiency between the dispersion and the mucosa. The emulsifying and dispersing effect of modified polysorbate 20 can reduce the particle size of ellagic acid dispersion and increase its contact area with intestinal absorption sites, thereby synergistically improving the intestinal absorption efficiency of ellagic acid through multiple pathways.

[0026] 4. This invention achieves maximum synergistic efficiency and ensures long-term product stability through precise control of component ratios and synergistic optimization of process parameters. The optimal mass ratio of fucoidan to ellagic acid ensures precise matching between the fucoidan coating sites and the hydrophobic regions of the ellagic acid molecules. The addition amount of modified polysorbate 20 and the chitosan-CPP complex is quantitatively controlled based on the ellagic acid loading, ensuring synergistic effects in emulsification, dispersion, and absorption promotion while avoiding abnormal viscosity and phase separation due to excessive component amounts. The optimized combination of process parameters further enhances the stability of intermolecular hydrogen bonds and electrostatic attraction, making the product less prone to recrystallization, aggregation, and other deterioration during long-term storage, thus maintaining its stable physicochemical properties and biological activity. Detailed Implementation

[0027] This invention proposes an ellagic acid composite solid dispersion and its preparation method. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the following will provide a more detailed description of the invention with reference to specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention.

[0028] The following fucoidan was purchased from Hangzhou Chentong Biochemical Technology Co., Ltd., and is mainly composed of fucose and small amounts of galactose, glucosamine, and galactosamine. The fucoidan chain is mainly composed of the [→3-α-l-Fucp2S, 4S-1→3-α-l-Fucp-1→3-α-l-Fucp2S-1→3-α-l-Fucp2S-1→] domain; the average molecular weight is 25-40 kDa. Polysorbate 20 was purchased from Sinopharm Chemical Reagent Co., Ltd., with an HLB value of 16.7. Xylooligosaccharides were purchased from Shanxi Borui Biotechnology Co., Ltd., with a xylobiose + xylotriose content ≥90%. Food-grade chitosan with a degree of deacetylation ≥85%; Casein phosphopeptide (CPP) was purchased from Hubei Haijia Biotechnology Co., Ltd., with a phosphate group content of ≥12%.

[0029] Example 1 The preparation method of modified polysorbate 20 is as follows: Step 1. Add 100g of food-grade polysorbate 20 and 50g of xylooligosaccharide to the reaction vessel, add 1.0g of sodium hydroxide catalyst, purge with nitrogen (flow rate 50mL / min), control the reaction temperature at 90℃, stir at 250rpm, and react at a constant temperature for 5h to obtain the grafted product. Step 2. After the reaction is complete, the system is cooled to 45°C, hydrogen is introduced and the pressure is maintained at 0.4 MPa, 0.2 g of palladium on carbon catalyst is added, and the hydrogenation reaction is carried out for 2.5 h. Step 3. Filter to remove the palladium on carbon catalyst, transfer the filtrate to a vacuum distillation apparatus, and distill for 3 hours at a temperature of 55℃ and a pressure of -0.085MPa to remove residual water, and obtain modified polysorbate 20.

[0030] Example 2 The preparation method of modified polysorbate 20 is as follows: Step 1. Add 100g of food-grade polysorbate 20 and 30g of xylooligosaccharide to the reactor, add 0.65g of sodium hydroxide catalyst, purge with nitrogen (flow rate 40mL / min), control the reaction temperature at 85℃, stir at 220rpm, and react at a constant temperature for 4.5h to obtain the grafted product. Step 2. After the reaction is complete, the system is cooled to 42°C, hydrogen is introduced and the pressure is maintained at 0.35 MPa, 0.39 g of palladium on carbon catalyst is added, and the hydrogenation reaction is carried out for 2 hours. Step 3. Filter to remove the palladium on carbon catalyst, transfer the filtrate to a vacuum distillation apparatus, and distill for 2.5 h at a temperature of 52℃ and a pressure of -0.08MPa to remove residual water and obtain modified polysorbate 20.

[0031] Example 3 The preparation method of modified polysorbate 20 is as follows: Step 1. Add 100g of food-grade polysorbate 20 and 80g of xylooligosaccharide to the reactor, add 1.7g of sodium hydroxide catalyst, purge with nitrogen (flow rate 60mL / min), control the reaction temperature at 95℃, stir at 280rpm, and react at a constant temperature for 5.5h to obtain the grafted product. Step 2. After the reaction is complete, the system is cooled to 48°C, hydrogen is introduced and the pressure is maintained at 0.45 MPa, 0.25 g of palladium on carbon catalyst is added, and the hydrogenation reaction is carried out for 3 h. Step 3. Filter to remove palladium on carbon catalyst, transfer the filtrate to a vacuum distillation apparatus, and distill for 3.5 h at a temperature of 58℃ and a pressure of -0.09MPa to remove residual water and obtain modified polysorbate 20.

[0032] Determination of hydrogenation degree: Iodine value titration method; Determination of xylooligosaccharide grafting rate: HPLC method; The results are shown in Table 1 below: Table 1 Degree of hydrogenation (%) Xylooligosaccharide grafting rate (%) Example 1 16 42.50 Example 2 12 35.80 Example 3 20 48.20 Example 4

[0033] The preparation method of chitosan-CPP complex is as follows: (1) Dissolve 20g of food-grade chitosan and 20g of casein phosphopeptide in a 2% (v / v) dilute acetic acid aqueous solution to prepare a mixed solution with a total concentration of 8mg / mL. (2) Adjust the pH to 7.3 with 0.1 mol / L sodium hydroxide solution, add 4 g of alkaline protease, and carry out the enzymatic hydrolysis reaction at 50℃ for 2.0 h; (3) Heat to 82℃ and keep warm for 18 min to inactivate the enzyme. After cooling to room temperature, centrifuge at 11000 rpm for 12 min, take the supernatant, freeze dry at -45℃ for 14 h to obtain chitosan-CPP complex.

[0034] Example 5 The preparation method of chitosan-CPP complex is as follows: (1) Dissolve 20g of food-grade chitosan and 16g of casein phosphopeptide in a 2% (v / v) dilute acetic acid aqueous solution to prepare a mixed solution with a total concentration of 6mg / mL. (2) Adjust the pH to 7.2 with 0.1 mol / L sodium hydroxide solution, add 3.6 g of alkaline protease, and carry out the enzymatic hydrolysis reaction at 48 °C for 1.8 h; (3) Heat to 80℃ and keep warm for 15 min to inactivate the enzyme. After cooling to room temperature, centrifuge at 10000 rpm for 10 min, take the supernatant, freeze dry at -40℃ for 12 h to obtain chitosan-CPP complex.

[0035] Example 6 The preparation method of chitosan-CPP complex is as follows: (1) Dissolve 20g of food-grade chitosan and 24g of casein phosphopeptide in a 2% (v / v) dilute acetic acid aqueous solution to prepare a mixed solution with a total concentration of 10mg / mL. (2) Adjust the pH to 7.5 with 0.1 mol / L sodium hydroxide solution, add 4.84 g of alkaline protease, and carry out the enzymatic hydrolysis reaction at 53 °C for 2.3 h; (3) Heat to 85℃ and keep warm for 20 min to inactivate the enzyme. After cooling to room temperature, centrifuge at 12000 rpm for 15 min, take the supernatant, freeze dry at -50℃ for 16 h to obtain chitosan-CPP complex.

[0036] Determination of particle size of the complex: Dynamic light scattering method (DLS, GB / Z 156-2025); Measurement of Zeta potential (mV): Electrophoretic light scattering method; Determination of ellagic acid binding rate: High performance liquid chromatography (HPLC) was used to determine the adsorption saturation of the complex for ellagic acid and to calculate the saturation rate. Determination of water solubility (g / L, 25℃): Ultraviolet spectrophotometry was used to determine the amount of the complex dissolved in a saturated aqueous solution; The results are shown in Table 2 below: Table 2

[0037] Example 7 A method for preparing an ellagic acid complex solid dispersion includes the following steps: S1. Fucoidan was dissolved in deionized water to obtain a fucoidan aqueous solution with a concentration of 1.2 mg / mL; ellagic acid was dissolved in a 50% (v / v) ethanol aqueous solution to obtain an ellagic acid suspension with a concentration of 0.6 mg / mL. S2. Mix the fucoidan aqueous solution with the ellagic acid suspension, wherein the mass ratio of fucoidan to ellagic acid is 2:1, and stir until homogeneous to obtain a mixture; S3. Add 0.12% by weight of the modified polysorbate 20 prepared in Example 1, and then add 0.22% by weight of the chitosan-CPP complex prepared in Example 4. Stir at 40°C and 180W ultrasonic power for 3.5h. S4. Transfer to a ball mill and ball mill at 180 rpm for 4.5 hours to obtain a homogeneous mixed solution; S5. Remove the solvent from the mixed solution by rotary evaporation under reduced pressure at 45°C, transfer it to a drying oven and dry it at 50°C for 7 hours, pulverize it and pass it through a 100-mesh sieve to obtain ellagic acid composite solid dispersion.

[0038] Example 8 A method for preparing an ellagic acid complex solid dispersion includes the following steps: S1. Fucoidan was dissolved in deionized water to obtain a fucoidan aqueous solution with a concentration of 0.8 mg / mL; ellagic acid was dissolved in a 40% (v / v) ethanol aqueous solution to obtain an ellagic acid suspension with a concentration of 0.3 mg / mL. S2. Mix the fucoidan aqueous solution with the ellagic acid suspension, wherein the mass ratio of fucoidan to ellagic acid is 1:1, and stir until homogeneous to obtain a mixture; S3. Add 0.08% by weight of the modified polysorbate 20 prepared in Example 1, and then add 0.15% by weight of the chitosan-CPP complex prepared in Example 5, and stir for 2.8 h at 35°C and 150 W ultrasonic power. S4. Transfer to a ball mill and ball mill at 150 rpm for 3.5 hours to obtain a homogeneous mixed solution; S5. The solvent in the mixed solution was removed by rotary evaporation under reduced pressure at 42°C, and then dried in a drying oven at 48°C for 6 hours. After pulverizing, the solution was passed through a 100-mesh sieve to obtain the ellagic acid composite solid dispersion.

[0039] Example 9 A method for preparing an ellagic acid complex solid dispersion includes the following steps: S1. Fucoidan was dissolved in deionized water to obtain a fucoidan aqueous solution with a concentration of 2.0 mg / mL; ellagic acid was dissolved in a 60% (v / v) ethanol aqueous solution to obtain an ellagic acid suspension with a concentration of 0.9 mg / mL. S2. Mix the fucoidan aqueous solution with the ellagic acid suspension, wherein the mass ratio of fucoidan to ellagic acid is 3:1, and stir until homogeneous to obtain a mixture. S3. Add 0.18% by weight of the modified polysorbate 20 prepared in Example 1, and then add 0.28% by weight of the chitosan-CPP complex prepared in Example 6, and stir at 45°C and 220W ultrasonic power for 4.2h. S4. Transfer to a ball mill and ball mill at 200 rpm for 5.0 h to obtain a homogeneous mixed solution; S5. The solvent in the mixed solution was removed by rotary evaporation under reduced pressure at 48°C, and then dried in a drying oven at 55°C for 8 hours. After pulverizing, the solution was passed through a 100-mesh sieve to obtain the ellagic acid composite solid dispersion.

[0040] Example 10 A method for preparing an ellagic acid complex solid dispersion includes the following steps: S1. Fucoidan was dissolved in deionized water to obtain a fucoidan aqueous solution with a concentration of 0.5 mg / mL; ellagic acid was dissolved in a 35% (v / v) ethanol aqueous solution to obtain an ellagic acid suspension with a concentration of 0.4 mg / mL. S2. Mix the fucoidan aqueous solution with the ellagic acid suspension, wherein the mass ratio of fucoidan to ellagic acid is 0.8:1, and stir until homogeneous to obtain a mixture; S3. Add 0.06% by weight of the modified polysorbate 20 prepared in Example 2, and then add 0.18% by weight of the chitosan-CPP complex prepared in Example 4, and stir for 2.5 h at 32°C and 130 W ultrasonic power. S4. Transfer to a ball mill and ball mill at 120 rpm for 3.0 h to obtain a homogeneous mixed solution; S5. The solvent in the mixed solution was removed by rotary evaporation under reduced pressure at 41°C, and then dried in a drying oven at 45°C for 5 hours. After pulverizing, the solution was passed through a 100-mesh sieve to obtain the ellagic acid composite solid dispersion.

[0041] Example 11 A method for preparing an ellagic acid complex solid dispersion includes the following steps: S1. Dissolve fucoidan in deionized water to obtain a fucoidan aqueous solution with a concentration of 1.5 mg / mL; dissolve ellagic acid in a 55% (v / v) ethanol aqueous solution to obtain an ellagic acid suspension with a concentration of 0.7 mg / mL. S2. Mix the fucoidan aqueous solution with the ellagic acid suspension, wherein the mass ratio of fucoidan to ellagic acid is 2.5:1, and stir until homogeneous to obtain a mixed solution; S3. Add 0.14% by weight of the modified polysorbate 20 prepared in Example 2, and then add 0.25% by weight of the chitosan-CPP complex prepared in Example 5, and stir at 42°C and 200W ultrasonic power for 3.8h. S4. Transfer to a ball mill and ball mill at 180 rpm for 4.2 hours to obtain a homogeneous mixed solution; S5. The mixed solution was subjected to reduced pressure rotary evaporation at 46℃ to remove the solvent, then transferred to a drying oven and dried at 52℃ for 7.5h. After pulverizing, it was passed through a 100-mesh sieve to obtain ellagic acid composite solid dispersion.

[0042] Example 12 A method for preparing an ellagic acid complex solid dispersion includes the following steps: S1. Fucoidan was dissolved in deionized water to obtain a fucoidan aqueous solution with a concentration of 2.2 mg / mL; ellagic acid was dissolved in a 65% (v / v) ethanol aqueous solution to obtain an ellagic acid suspension with a concentration of 1.0 mg / mL. S2. Mix the fucoidan aqueous solution with the ellagic acid suspension, wherein the mass ratio of fucoidan to ellagic acid is 3.5:1, and stir until homogeneous to obtain a mixed solution; S3. Add 0.19% by weight of the modified polysorbate 20 prepared in Example 2, and then add 0.30% by weight of the chitosan-CPP complex prepared in Example 6, and stir at 48°C and 250W ultrasonic power for 4.8h. S4. Transfer to a ball mill and ball mill at 220 rpm for 5.5 hours to obtain a homogeneous mixed solution; S5. The solvent in the mixed solution was removed by rotary evaporation under reduced pressure at 49°C, and then dried in a drying oven at 58°C for 10 hours. After pulverizing, the solution was passed through a 100-mesh sieve to obtain ellagic acid composite solid dispersion.

[0043] Example 13 A method for preparing an ellagic acid complex solid dispersion includes the following steps: S1. Fucoidan was dissolved in deionized water to obtain a fucoidan aqueous solution with a concentration of 0.3 mg / mL; ellagic acid was dissolved in a 30% (v / v) ethanol aqueous solution to obtain an ellagic acid suspension with a concentration of 0.2 mg / mL. S2. Mix the fucoidan aqueous solution with the ellagic acid suspension, wherein the mass ratio of fucoidan to ellagic acid is 0.5:1, and stir until homogeneous to obtain a mixture; S3. Add 0.05% by weight of the modified polysorbate 20 prepared in Example 3, and then add 0.12% by weight of the chitosan-CPP complex prepared in Example 4, and stir at 30°C and 100W ultrasonic power for 2.0h. S4. Transfer to a ball mill and ball mill at 100 rpm for 2.5 hours to obtain a homogeneous mixed solution; S5. Remove the solvent from the mixed solution by rotary evaporation under reduced pressure at 40°C, transfer it to a drying oven and dry it at 40°C for 3 hours, pulverize it and pass it through a 100-mesh sieve to obtain ellagic acid composite solid dispersion.

[0044] Example 14 A method for preparing an ellagic acid complex solid dispersion includes the following steps: S1. Fucoidan was dissolved in deionized water to obtain a fucoidan aqueous solution with a concentration of 1.8 mg / mL; ellagic acid was dissolved in a 70% (v / v) ethanol aqueous solution to obtain an ellagic acid suspension with a concentration of 0.8 mg / mL. S2. Mix the fucoidan aqueous solution with the ellagic acid suspension, wherein the mass ratio of fucoidan to ellagic acid is 4.0:1, and stir until homogeneous to obtain a mixed solution; S3. Add 0.20% by weight of the modified polysorbate 20 prepared in Example 3, and then add 0.27% by weight of the chitosan-CPP complex prepared in Example 6, and stir at 50°C and 280W ultrasonic power for 5.0h. S4. Transfer to a ball mill and ball mill at 240 rpm for 6.0 h to obtain a homogeneous mixed solution; S5. Remove the solvent from the mixed solution by rotary evaporation under reduced pressure at 50°C, transfer it to a drying oven and dry it at 60°C for 11 hours, pulverize it and pass it through a 100-mesh sieve to obtain ellagic acid composite solid dispersion.

[0045] Comparative Example 1 The difference between this comparative example and Example 7 is that modified polysorbate 20 was not added, but only chitosan-CPP complex was added.

[0046] Comparative Example 2 The difference between this comparative example and Example 7 is that the chitosan-CPP complex was not added, but only modified polysorbate 20 was added.

[0047] Comparative Example 3 The difference between this comparative example and Example 7 is that fucoidan was not added, and only ellagic acid, modified polysorbate 20 and chitosan-CPP complex were retained.

[0048] Comparative Example 4 The difference between this comparative example and Example 7 is that modified polysorbate 20 and chitosan-CPP complex were not added, but replaced with an equal mass of unmodified polysorbate 20.

[0049] Comparative Example 5 The difference between this comparative example and Example 7 is that only ellagic acid and fucoidan are retained, and no surfactants or complexes are added.

[0050] Comparative Example 6 The difference between this comparative example and Example 7 is that only ellagic acid and modified polysorbate 20 are retained, and fucoidan and chitosan-CPP complex are not added.

[0051] Comparative Example 7 The difference between this comparative example and Example 7 is that the modified polysorbate 20 prepared in Example 1 is replaced with an equal mass of unmodified polysorbate 20.

[0052] Comparative Example 8 The difference between this comparative example and Example 7 is that the chitosan-CPP complex prepared in Example 4 is replaced with an equal mass of single chitosan.

[0053] Comparative Example 9 The difference between this comparative example and Example 7 is that the chitosan-CPP complex prepared in Example 4 is replaced with an equal mass of single CPP.

[0054] Comparative Example 10 The difference between this comparative example and Example 7 is that fucoidan is replaced with an equal mass of gum arabic (other parameters remain unchanged).

[0055] Comparative Example 11 The difference between this comparative example and Example 7 is that the mass ratio of fucoidan to ellagic acid is 5:1.

[0056] Comparative Example 12 The difference between this comparative example and Example 7 is that the mass ratio of fucoidan to ellagic acid is 0.1:1.

[0057] Comparative Example 13 The difference between this comparative example and Example 7 is that the amount of modified polysorbate 20 added is 0.3% of the mass of ellagic acid.

[0058] Comparative Example 14 The difference between this comparative example and Example 7 is that the amount of chitosan-CPP complex added is 0.05% of the mass of ellagic acid.

[0059] Performance testing: 1. Determination of ellagic acid solubility (25℃, g / L) Ultraviolet spectrophotometry was used: 50 mg of ellagic acid composite solid dispersion was accurately weighed and added to 100 mL of deionized water. The mixture was shaken at 25 °C (150 rpm) for 24 h to reach dissolution equilibrium. The supernatant was filtered through a 0.22 μm filter membrane, and the absorbance was measured at 254 nm using deionized water as a blank control. The concentration of ellagic acid in the saturated solution was calculated based on the ellagic acid standard curve, which is the solubility. 2. Determination of the crystallinity (%) of ellagic acid Powder X-ray diffraction was used: the dried solid dispersion powder was taken and scanned using an X-ray diffractometer with a scanning range of 2θ = 5°-40°, a scanning speed of 2° / min, and a step size of 0.02°; the crystalline peaks and amorphous peaks were separated using MDIJade 6.5 software, and the crystallinity was calculated according to the formula "crystallinity = ∑Iα / (∑Iα+∑Iam)×100%" (∑Iα is the total area of ​​the crystalline peaks, and ∑Iam is the total area of ​​the amorphous peaks). 3. Determination of average particle size (nm) and zeta potential (mV) of the dispersion Average particle size: Dynamic light scattering method (DLS, refer to GB / Z 156-2025): The solid dispersion was prepared into an aqueous solution of 0.1 mg / mL, ultrasonically dispersed for 10 min, injected into the sample cell of the particle size analyzer, and measured at 25℃. Each sample was measured in parallel 3 times and the average value was taken. Zeta potential: Electrophoretic light scattering method: The sample concentration was measured at 25℃ and pH 7.0, with the same particle size as above. The measurements were performed in parallel for 3 times and the average value was taken. 4. Determination of storage stability (% decrease in solubility after 6 months) The solid dispersion was sealed in an aluminum foil bag and stored in a constant temperature and humidity chamber at 25°C and 60% relative humidity for 6 months. Samples were taken at 0 months, 3 months and 6 months, and the solubility was tested according to the "Method for Determination of Ellagic Acid Solubility". The solubility was calculated according to the formula "Solubility decrease % = (initial solubility - 6-month solubility) / initial solubility × 100%". 5. Determination of heavy metals (Pb, As, mg / kg) Inductively coupled plasma mass spectrometry (ICP-MS, refer to GB / T 4333.12-2025) was used: 1.0 g of solid dispersion sample was accurately weighed, 8 mL of nitric acid was added, and digestion was performed using a microwave digester (temperature program: 50℃ for 5 min, 100℃ for 5 min, 180℃ for 20 min); after cooling, the digest was diluted to 25 mL, and the Pb and As contents were determined using ICP-MS. Quality control was performed using national standard reference materials. The results are shown in Table 3 below: Table 3. System stability and physicochemical properties of ellagic acid composite solid dispersions

[0060] As shown in Table 3, the physicochemical properties of the examples are significantly better than those of the comparative examples. Specifically, the solubility of the examples is 0.32-0.51 g / L, which is 1.7-6.4 times that of the comparative examples (0.08-0.30 g / L). Among them, Example 12 (1.0 mg / mL ellagic acid concentration) has the highest solubility (0.51 g / L), indicating that the synergistic emulsification and electrostatic complexing effect of modified polysorbate 20 and chitosan-CPP complex can effectively break the intermolecular aggregation of ellagic acid and improve water solubility. The crystallinity of the examples is only 7.5%-10.3%, which is much lower than that of the comparative examples (15.8%-36.7%), and the degree of amorphization is higher, avoiding the dissolution obstacles caused by ellagic acid crystallization. The average particle size of the examples is 82.3-108.5 nm, with good uniformity and Zet The absolute value of the electrostatic potential was 24.3-31.5 mV, higher than that of the comparative example (11.6-24.3 mV). The strong electrostatic repulsion inhibited the aggregation of the dispersion and ensured the stability of the system. The solubility of the examples decreased by only 2.5%-4.2% after 6 months, while that of the comparative example decreased by 10.3%-27.8%. It can be seen that the cross-linking network formed by the xylooligosaccharide branches of modified polysorbate 20 and the chitosan-CPP complex can effectively maintain the amorphous state of ellagic acid and avoid recrystallization during storage. The Pb and As contents of all examples and comparative examples met the GB2760 food grade standard. Moreover, due to the use of food grade modification process, the examples had lower heavy metal residues (Pb≤0.007-0.011 mg / kg, As≤0.003-0.005 mg / kg), and were safer.

[0061] 6. Determination of oral bioavailability (%) HPLC-MS / MS was used in a rat model: Healthy SD rats (weighing 200±20g) were randomly divided into 19 groups of 6 rats each. After fasting for 12 hours, ellagic acid was administered orally at a dose of 50mg / kg as a solid dispersion suspension (0.5% sodium carboxymethyl cellulose as a suspending agent). Blood samples of 0.5mL were collected from the orbital cavity at 0.25, 0.5, 1, 2, 4, 6, 8, 12, and 24 hours after administration. Plasma was separated by centrifugation (3000rpm, 10min). 0.2mL of plasma was collected, and 0.6mL of methanol was added to precipitate proteins. After centrifugation, the supernatant was filtered through a 0.22μm filter membrane. The concentration of ellagic acid was determined by HPLC-MS / MS. The area under the curve (AUC) was calculated using DAS3.0 software. 0-24h Using the intravenous injection group (with the same dose of ellagic acid ethanol solution) as a reference, the bioavailability was calculated according to the formula: "Bioavailability (%) = (AUC of oral group)". 0-24h / AUC in intravenous injection group 0-24h Calculate using ")×100%".

[0062] 7. Determination of gastrointestinal degradation rate (pH 1.2, pH 7.4, %) HPLC method (simulating gastrointestinal fluid environment): Simulated gastric juice (pH 1.2): Accurately weigh the solid dispersion sample (containing 10 mg ellagic acid), add 50 mL of pH 1.2 hydrochloric acid solution (containing 0.32% pepsin), and incubate at 37°C and 100 rpm for 4 h with constant temperature shaking; Simulated intestinal fluid (pH 7.4): Add 50 mL of pH 7.4 phosphate buffer (containing 1% trypsin) to the same sample volume as above, and incubate at 37°C and 100 rpm for 4 h with constant temperature shaking; After incubation, 100 mL of methanol was added to terminate the reaction, and the mixture was extracted by sonication for 20 min. The supernatant was collected by centrifugation (8000 rpm, 15 min), filtered through a 0.22 μm filter membrane, and the remaining ellagic acid content was determined by HPLC. The degradation rate (%) was calculated according to the formula "degradation rate (%) = (initial ellagic acid mass - remaining ellagic acid mass) / initial ellagic acid mass × 100%".

[0063] The results are shown in Table 4 below: Table 4. Absorption, utilization, and anti-degradation capabilities of ellagic acid composite solid dispersions

[0064] As shown in Table 4, the ellagic acid composite solid dispersions prepared in Examples 8, 11, 12, and 13 of this invention are significantly superior to Comparative Examples 1-14 and pure ellagic acid in terms of improved oral bioavailability and gastrointestinal anti-degradation ability. Specifically, the bioavailability of the examples is 61.5%-75.3%, which is 7.5-9.2 times that of pure ellagic acid (8.2%) and 11.2%-357.3% higher than that of the comparative examples (14.3%-55.7%). Among them, Example 12 has the highest bioavailability (75.3%). It can be seen that the modified polysorbate 20, chitosan-CPP complex, and fucoidan have a synergistic effect, which can effectively improve the intestinal mucosal permeability of ellagic acid and solve the core problem of poor oral absorption. The degradation rates in the examples were only 7.2%-10.5% in simulated gastric juice (pH 1.2) and 4.8%-7.2% in simulated intestinal juice (pH 7.4), far lower than pure ellagic acid and all comparative examples. This is because the molecular encapsulation network formed by the composite system can effectively isolate the enzymes in the gastrointestinal juice from contact with ellagic acid, inhibit its pH-dependent degradation, and ensure the effective concentration of the drug in the intestine. Comparative example 5, which only retained ellagic acid and fucoidan, had a bioavailability of only 15.8% and a gastric juice degradation rate of 58.5%.

[0065] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments, without departing from the spirit and technical essence of the present invention. Therefore, any simple modifications, equivalent substitutions, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the technical solutions of the present invention, shall still fall within the scope of protection of the present invention.

Claims

1. A process for the preparation of ellagic acid complex solid dispersion, characterized by, The method comprises the following steps: S1. Dissolve fucoidan in deionized water to obtain a fucoidan aqueous solution; dissolve ellagic acid in an ethanol aqueous solution to obtain an ellagic acid suspension; S2. Mix the fucoidan aqueous solution and the ellagic acid suspension, and stir uniformly to obtain a mixed solution; S3. Add modified polysorbate 20, and then add a chitosan-CPP compound, and stir at a temperature of 30-50℃ and an ultrasonic power of 100-280W for 2-5h; S4. Transfer into a ball mill, and ball mill at a rotating speed of 100-240rpm for 2.5-6h to obtain a uniformly mixed solution; S5. Remove the solvent from the mixed solution by rotary evaporation under reduced pressure, transfer into a drying box for drying, crush, and then pass through a 100-mesh sieve to obtain an ellagic acid composite solid dispersion.

2. A process for the preparation of ellagic acid complex solid dispersion as claimed in claim 1, wherein, The fucoidan in S1 is obtained by water extraction and purification of seaweed and meets the following conditions: (1) mainly composed of fucose and a small amount of galactose, glucosamine and galactosamine; (2) the fucoidan chain is mainly composed of [→3-α-l-Fucp2S, 4S-1→3-α-l-Fucp-1→3-α-l-Fucp2S-1→3-α-l-Fucp2S-1→] domain; (3) the average molecular weight is 25-40kDa.

3. A process for the preparation of ellagic acid complex solid dispersion as claimed in claim 1, wherein, The concentration of the fucoidan aqueous solution in S1 is 0.1mg / mL-2.5mg / mL; and the concentration of the ellagic acid suspension is 0.1mg / mL-1mg / mL.

4. A process for the preparation of ellagic acid complex solid dispersion as claimed in claim 1, wherein, The mass ratio of fucoidan to ellagic acid in the mixed solution in S2 is (0.2-4):

1.

5. A process for the preparation of ellagic acid complex solid dispersion as claimed in claim 1, wherein, The addition amount of the modified polysorbate 20 in S3 is 0.05%-0.2% of the mass of the ellagic acid; and the addition amount of the chitosan-CPP compound is 0.1%-0.3% of the mass of the ellagic acid.

6. A process for the preparation of ellagic acid complex solid dispersion as claimed in claim 1, wherein, The preparation method of the modified polysorbate 20 in S3 is as follows: Step 1. Add polysorbate 20 and xylo-oligosaccharide into a reaction kettle, add sodium hydroxide as a catalyst, protect under nitrogen, control the reaction temperature at 80-100℃, the stirring speed at 200-300rpm, and react for 4-6h to obtain a grafted product; Step 2. Cool to 40-50℃, pass in hydrogen, add a palladium-carbon catalyst, and hydrogenate for 2-3h; Step 3. Filter to remove the catalyst, and remove the residual water by distillation under reduced pressure to obtain the modified polysorbate 20.

7. A process for the preparation of ellagic acid complex solid dispersion as claimed in claim 6, wherein, The mass ratio of the polysorbate 20 to the xylo-oligosaccharide in Step 1 is 1:(0.3-0.8).

8. A process for the preparation of ellagic acid complex solid dispersion as claimed in claim 1, wherein, The preparation method of the chitosan-CPP compound in S3 is as follows: (1) according to a mass ratio of 1:(0.6-1.5), dissolve food-grade chitosan and casein phosphopeptide in a 2% dilute acetic acid aqueous solution to obtain a mixed solution with a total concentration of 5-12mg / mL; (2) slightly adjust the pH to 7.2-7.5 with a sodium hydroxide solution, add alkaline protease, and perform enzymatic reaction at a temperature of 48-55℃ for 1.5-2.5h; (3) heat to 80-85℃ for 15-20min to inactivate the enzyme, centrifuge after cooling to obtain the supernatant, and freeze-dry to obtain the chitosan-CPP compound.

9. A process for the preparation of ellagic acid complex solid dispersion as claimed in claim 8, wherein, The addition amount of the alkaline protease is 0.06%-0.12% of the mass of the mixed solution.

10. A ellate complex solid dispersion prepared according to the process of any one of claims 1 to 9.

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