Temperature-sensitive hydrogel nasal preparation for treating brain hypoxia related diseases and preparation method and application thereof

Abstract

The invention provides a temperature-sensitive hydrogel preparation for treating brain hypoxia related diseases, the active ingredient of the temperature-sensitive hydrogel preparation is a ligustilide cyclodextrin inclusion compound, and the temperature-sensitive hydrogel preparation is prepared from ligustilide and hydroxypropyl-beta-cyclodextrin through an inclusion effect. Compared with the prior art, the invention has the following advantages: the cyclodextrin inclusion technology can effectively improve the problems of low stability, poor solubility and the like of ligustilide, and the poloxamer temperature-sensitive hydrogel has good stability, biocompatibility and slow release performance. The cyclodextrin inclusion compound and the hydrogel are combined to be applied to the nasal preparation, after the temperature-sensitive hydrogel enters the nasal cavity, the gel form at the physiological temperature is converted into a semi-solid and is adsorbed on the nasal mucosa, the residence time of the medicine at the administration position is prolonged, the slow release effect is achieved, meanwhile, the administration dosage can be reduced, the side effect of the medicine is relieved, and the bioavailability of the medicine is improved. The compound can be used for various brain diseases, is expected to overcome the defects of the traditional nasal preparation, and improves the curative effect of the medicine and the acceptability of a patient.

Description

Technical Field

[0001] This application relates to the field of pharmaceutical preparation technology, specifically to a thermosensitive hydrogel nasal preparation for treating brain hypoxia-related diseases, its preparation method, and its application. Background Technology

[0002] Because human neural tissue is most sensitive to changes in the internal and external environment, brain function damage occurs earliest and is more severe under hypoxic conditions, and the longer the exposure time, the more severe the damage. Traditional treatments for brain diseases are mostly administered orally or by injection. Oral administration requires absorption through the gastrointestinal tract and the first-pass effect in the liver, resulting in lower effective concentrations in the brain and a slower onset of action. While injection can improve the speed of drug entry into the brain to some extent, it carries risks of invasive procedures and poor patient compliance. Nasal administration has unique advantages; the nasal mucosa is richly vascularized, allowing drugs to bypass the blood-brain barrier and directly enter the brain, improving delivery efficiency and reducing systemic adverse reactions. However, current nasal formulations for brain diseases still have some shortcomings, such as limited drug retention time in the nasal cavity, preventing continuous and stable drug delivery to the brain; and the need for further improvement in the safety and stability of the formulations. In existing technologies, commonly used drug formulations for the treatment of brain diseases include nasal drops and sprays. Because of the presence of mucus and cilia in the nasal cavity, foreign substances such as drugs are removed, resulting in a short residence time of the drug at the administration site and weak adhesion of the nasal mucosa, which affects drug absorption.

[0003] Ligustilide (LIG), mainly derived from the traditional Chinese medicines Ligusticum chuanxiong and Angelica sinensis, is a pale yellow oily liquid with a distinctive aroma. It is soluble in organic solvents such as methanol and ethanol and has strong antispasmodic, antiasthmatic, sedative, and anti-inflammatory effects. It can improve microcirculation, relax smooth muscle, fight tumors, and enhance the body's immune regulation. According to previous research by our group, ligustilide can also increase the oxygen release of hemoglobin in tissues, improve tissue hypoxia levels, and alleviate high-altitude hypoxia. However, it has disadvantages such as low stability and poor water solubility, which affect its widespread use. Cyclodextrin inclusion complexation is a promising method to improve water solubility, bioavailability, and stability. Summary of the Invention

[0004] In view of the above-mentioned technical limitations, this application proposes a thermosensitive hydrogel nasal preparation for treating cerebral hypoxia-related diseases, its preparation method and application; it can enhance the stability and solubility of ligustilide, improve the bioavailability and brain concentration of ligustilide, improve patient medication compliance, and achieve precise treatment of cerebral hypoxia, overcoming the deficiencies and defects mentioned in the background art.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] The inventive point of this application is to provide a thermosensitive hydrogel formulation for treating brain hypoxia-related diseases. The active ingredient of the formulation is ligustilide cyclodextrin inclusion complex, which is prepared by inclusion complex of ligustilide and hydroxypropyl-β-cyclodextrin. In the ligustilide cyclodextrin inclusion complex, the mass ratio of ligustilide to hydroxypropyl-β-cyclodextrin is (1:4) to (1:14); preferably 1:10.

[0007] Optionally, in the above-mentioned thermosensitive hydrogel formulation for treating cerebral hypoxia-related diseases, the preparation method of the ligustilide cyclodextrin inclusion complex is as follows: a specified amount of hydroxypropyl-β-cyclodextrin is dissolved in ultrapure water by stirring to obtain a hydroxypropyl-β-cyclodextrin solution; a specified amount of ligustilide is dissolved in an organic solvent to obtain a ligustilide solution; under stirring conditions, the ligustilide solution is added to the hydroxypropyl-β-cyclodextrin solution for inclusion; then freeze-drying is performed, the freeze-dried powder is washed with water, then washed with petroleum ether, and evaporated to a constant weight to obtain the ligustilide cyclodextrin inclusion complex.

[0008] Optionally, in the above-mentioned thermosensitive hydrogel formulation for treating brain hypoxia-related diseases, the organic solvent is anhydrous ethanol; the specific inclusion conditions are an inclusion temperature of 40°C, an inclusion time of 3 h, and an inclusion rotation speed of 700 r / min.

[0009] Optionally, the above-mentioned thermosensitive hydrogel formulation for treating brain hypoxia-related diseases is obtained by dissolving poloxamer 407 and poloxamer 188 in ultrapure water, stirring on ice to dissolve, adding hydroxypropyl methylcellulose (HPMC) and stirring evenly, and then refrigerating at 4°C overnight to obtain a clear and evenly dispersed hydrogel solution.

[0010] Optionally, in the above-mentioned thermosensitive hydrogel formulation for treating brain hypoxia-related diseases, the amount of poloxamer 407 added is 20%-28%, preferably 24%, by mass-volume ratio; the amount of poloxamer 188 added is 1%-3%, preferably 1%; and the amount of hydroxypropyl methylcellulose (HPMC) added is 1%-5%, preferably 3%.

[0011] Poloxamer 407 and 188 are used to provide the basic skeletal structure of the gel, while adjusting the gelation temperature and time in different proportions; hydroxypropyl methylcellulose regulates the swelling properties of the gel.

[0012] In the concentration range of 0-30 mmol / L, the apparent solubility of ligustilide in cyclodextrin inclusion complexes increases with the increase of HP-β-CD concentration. Its phase dissolution curve is of the AL type, and it can form a 1:1 inclusion complex. Compared with ligustilide, the cumulative dissolution of cyclodextrin inclusion complexes is significantly increased.

[0013] The second inventive point of this application is to provide a method for preparing the above-mentioned thermosensitive hydrogel formulation for treating brain hypoxia-related diseases, comprising the following steps:

[0014] S1. Hydroxypropyl-β-cyclodextrin was dissolved in ultrapure water by stirring to obtain a hydroxypropyl-β-cyclodextrin solution; a specific amount of ligustilide was dissolved in an organic solvent to obtain a ligustilide solution; under stirring, the ligustilide solution was added to the hydroxypropyl-β-cyclodextrin solution and stirred to include the ligustilide; then lyophilized, the lyophilized powder was washed with water, then washed with petroleum ether, and evaporated to a constant weight to obtain the ligustilide cyclodextrin inclusion complex.

[0015] S2. Dissolve poloxamer 407 and poloxamer 188 in ultrapure water, stir on ice until dissolved, add hydroxypropyl methylcellulose (HPMC) and stir until homogeneous, then refrigerate at 4°C overnight to prepare a clear, uniformly dispersed thermosensitive hydrogel solution.

[0016] S3. Disperse the ligustilide cyclodextrin inclusion complex prepared in step S1 in the thermosensitive hydrogel solution prepared in step S2, and adjust the pH to 5.5-6.5 to obtain a thermosensitive hydrogel formulation for treating brain hypoxia-related diseases.

[0017] Optionally, in the above preparation method, in step S1, the mass ratio of ligustilide to hydroxypropyl-β-cyclodextrin is (1:4)-(1:14), preferably 1:10; the organic solvent is anhydrous ethanol; the specific inclusion conditions are an inclusion temperature of 40℃, an inclusion time of 3 h, and an inclusion rotation speed of 700 r / min.

[0018] Optionally, in the above preparation method, in step S2, the amount of poloxamer 407 added is 20%-28%, preferably 24%; the amount of poloxamer 188 added is 1%-3%, preferably 1%; and the amount of hydroxypropyl methylcellulose (HPMC) added is 1%-5%, preferably 3%.

[0019] The third inventive point of this application is to provide the application of the above-mentioned thermosensitive hydrogel formulation in the preparation of a drug for targeted and precise treatment of brain tissue hypoxia.

[0020] Optionally, in the above-described application, the dosage form of the drug is a nasal preparation.

[0021] This nasal formulation achieves efficient drug absorption by uniformly dispersing cyclodextrin inclusion complexes in a hydrogel matrix and utilizing the adhesive properties of the hydrogel within the nasal cavity.

[0022] Compared with the prior art, this application has the following advantages:

[0023] In this application, the cyclodextrin inclusion complex technology effectively improves the problems of low stability and poor solubility of ligustilide, while poloxamer thermosensitive hydrogel exhibits good stability, biocompatibility, and sustained-release properties. Combining the cyclodextrin inclusion complex with the hydrogel in nasal formulations allows the temperature-sensitive hydrogel to transform from a gel state at physiological temperature into a semi-solid state upon entering the nasal cavity, adsorbing onto the nasal mucosa and prolonging the drug's residence time at the administration site, achieving a sustained-release effect. Simultaneously, it can reduce the dosage and alleviate drug side effects, making it suitable for various brain diseases. This technology is expected to overcome the shortcomings of traditional nasal formulations, improve drug efficacy, and enhance patient acceptance.

[0024] The thermosensitive hydrogel nasal formulation based on ligustilide cyclodextrin inclusion complex provided in this application can be used to treat abnormal brain tissue energy metabolism caused by hypoxia. Through nasal administration, it achieves both brain-targeted and systemic drug effects, and has the following advantages:

[0025] 1) Improve drug stability: Cyclodextrin inclusion complexation effectively protects ligustilide from external environmental and intranasal environmental factors, reduces drug degradation and inactivation, improves drug solubility, and reduces drug storage conditions;

[0026] 2) Enhanced drug release: Based on the study of dissolution in a simulated nasal cavity environment, compared with drug monomers, hydrogels can effectively increase the cumulative dissolution rate of ligustilide and can play a local sustained-release role, prolonging the administration time and improving drug utilization.

[0027] 3) Improved drug bioavailability: Compared with ligustilide, the hydrogel significantly increased in vivo absorption and improved bioavailability. The AUC(0-∞) of the hydrogel group rats was 1.70 times that of the drug group; the Cmax was 1.31 times that of the drug group. After the drug was administered into the nasal cavity, it rapidly accumulated in the brain tissue, and the drug concentration was significantly higher than that in other tissues, maintaining the effective concentration of the drug in the nasal cavity, reducing the number of administrations, and improving the therapeutic effect.

[0028] 4) Simple preparation method: The preparation method of this technology is relatively simple, easy to operate and control, and suitable for industrialization and mass production. Attached Figure Description

[0029] Figure 1 The image shown is an infrared and thermal image of each stage in the formation of the ligustilide cyclodextrin inclusion complex, as illustrated in one embodiment of this application; wherein... Figure 1 A shows the infrared and thermal images of ligustilide. Figure 1 B shows the infrared and thermal images of hydroxypropyl-β-cyclodextrin (HP-β-CD). Figure 1 C represents the infrared and thermal images of the physical mixture of the two. Figure 1 D shows the infrared and thermal images of the inclusion complex (LIG-IC) formed by the two.

[0030] Figure 2 The results of a drug intermediate stability study (n=3) during the preparation of the ligustilide cyclodextrin inclusion complex are shown in one embodiment of this application. ±s); where, Figure 2 A represents the statistical curves of the loss rate of the drug group (ligustilide), the physical mixture group, and the ligustilide cyclodextrin inclusion complex group at different temperatures over time. Figure 2 B is a statistical curve of the loss rate of the drug group (ligustilide), the physical mixture group and the ligustilide cyclodextrin inclusion complex group under different light conditions over time. Figure 2 C is a statistical curve of the loss rate over time under the same conditions for the drug group (ligustilide), the physical mixture group, and the ligustilide cyclodextrin inclusion complex group.

[0031] Figure 3 The diagram shows the specific morphology of a thermosensitive hydrogel nasal preparation containing ligustilide cyclodextrin inclusion complex prepared in one embodiment of this application for the treatment of hypoxia-related brain disorders.

[0032] Figure 4 The graph shown is a cumulative release rate curve over time (n=3) of a thermosensitive hydrogel nasal formulation containing ligustilide cyclodextrin inclusion complex prepared in one embodiment of this application for the treatment of hypoxia-related brain disorders. ±s, compared with the ligustilide drug group).

[0033] Figure 5 The image shown is a plasma drug content curve over time in rats (n=6) of a thermosensitive hydrogel nasal formulation containing ligustilide cyclodextrin inclusion complex prepared in one embodiment of this application for the treatment of hypoxia-related brain disorders, after intranasal administration. ±s, compared with the ligustilide drug group).

[0034] Figure 6 The image shown is a tissue distribution diagram of the drug content in rats after intranasal administration of a thermosensitive hydrogel nasal preparation containing ligustilide cyclodextrin inclusion complex for the treatment of hypoxia-related brain disorders, prepared in one embodiment of this application (n=6). ±s; compared with brain tissue, *P<0.05, **P<0.01).

[0035] Figure 7 The illustration shows the effect of a thermosensitive hydrogel nasal formulation containing ligustilide cyclodextrin inclusion complex, prepared in one embodiment of this application, on improving serum inflammatory factors and brain tissue oxidative stress-related indicators (IL-1β, IL-6, TNF-α, malondialdehyde (MDA), glutathione (GSH), and superoxide dismutase (SOD) in hypoxic rats (n=6). ±s); Among them, the animals were divided into the following groups: Normoxic Control Group (CG group), Hypoxia Model Group (HH group), Acetazolamide Group (AC group), Ligustilide Group (LIG group), Nasal Drops Group, Spray Group, Empty Carrier Group (Black@Gel), and Low, Medium, and High Dose Ligustilide Hydrogel Groups (LIC-IC@Gel-L, LIC-IC@Gel-M, LIC-IC@Gel-H) (Note: Compared with the CG group, *P<0.05, **P<0.01; compared with the MG group, # P<0.05, ## P < 0.01; compared with the LIG-IC@Gel group, △ P < 0.05.

[0036] Figure 8 The image shows the comprehensive score of the proportions of each raw material in the preparation of the ligustilide cyclodextrin inclusion complex in one embodiment of this application.

[0037] Figure 9 The image shows a thermosensitive hydrogel nasal preparation containing ligustilide cyclodextrin inclusion complex, prepared in one embodiment of this application, for the treatment of brain hypoxia-related diseases. The image also shows the comprehensive evaluation results of the effect of the ratio of the three raw materials of the hydrogel on the gelation temperature and gelation time. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this application clearer, a more detailed description is provided below. However, it should be understood that the description herein is merely for explaining this application and is not intended to limit its scope.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. All reagents and instruments used herein are commercially available, and the characterization methods involved can be found in relevant descriptions in the prior art, and will not be repeated here.

[0040] To further understand this application, the following detailed description is provided in conjunction with the preferred embodiments.

[0041] Example 1

[0042] A method for preparing a thermosensitive hydrogel nasal formulation based on ligustilide cyclodextrin inclusion complex includes the following steps:

[0043] (1) Preparation of ligustilide cyclodextrin inclusion complex: Weigh an appropriate amount of HP-β-CD and place it in a beaker. Add ultrapure water and stir to dissolve. Take an appropriate amount of ligustilide and place it in a 0.5 mL centrifuge tube. Ensure that the drug-excipient ratio is 1:10. Dissolve it with 0.5 mL of anhydrous ethanol and transfer it to a beaker. Take an appropriate amount of anhydrous ethanol and wash the centrifuge tube in small amounts several times. Transfer it to a beaker. Set the magnetic stirrer temperature to 30℃ and the speed to 700 r / min. Perform inclusion treatment for 3 h. Collect the sample solution and freeze it in a -20℃ freezer for 24 h. Process it in a freeze dryer for 48 h to obtain a solid powder. Wash it with water and then wash it three times with petroleum ether. Evaporate to a constant weight to obtain the cyclodextrin inclusion complex. Weigh it for later use. Figure 1 The results showed that ligustilide cyclodextrin inclusion complex was formed.

[0044] (2) Preparation of thermosensitive hydrogel matrix: The thermosensitive hydrogel was prepared by the "cold dissolution method". P407 (24% w / v) and P188 (1% w / v) were dissolved in ultrapure water and stirred on ice to dissolve. Then, an appropriate amount of HPMC (1~3% w / v) was added and stirred evenly. The mixture was refrigerated at 4°C overnight to allow it to fully swell and obtain a clear and uniformly dispersed gel solution.

[0045] (3) Preparation of drug-loaded hydrogel: The ligustilide cyclodextrin inclusion complex was dispersed in a thermosensitive matrix (17.5%), stirred evenly, and fully swollen to form a light yellow, uniform gel solution. The pH was adjusted to 5.5~6.5 and stored at 4℃ for later use.

[0046] (4) Application method: The drug was administered slowly by multiple drops into the nasal cavity using a micropipette. During the administration process, the rat's head was kept facing upwards. The hydrogel rapidly gelled at the nasal cavity temperature, continuously releasing the drug. The maximum administration volume was 50 μL per side.

[0047] Example 2

[0048] A method for preparing a thermosensitive hydrogel nasal formulation based on ligustilide cyclodextrin inclusion complex includes the following steps:

[0049] First, the cyclodextrin inclusion complex was prepared. 2 g of hydroxypropyl-β-cyclodextrin was weighed and placed in a 25 mL beaker, dissolved in an appropriate amount of pure water. 0.2 g of ligustilide was accurately weighed, dissolved in 0.5 mL of anhydrous ethanol, and transferred to the beaker. The mixture was stirred for 3 h at 40 °C and 700 r / min using a magnetic stirrer. After stirring, the solution was filtered, the solid was collected, and the solid was freeze-dried at -48 °C for 4 h to obtain a white solid powder. This powder was washed with water, then washed three times with petroleum ether, and evaporated to a constant weight to obtain the cyclodextrin inclusion complex.

[0050] from Figure 2It can be seen that, compared with ligustilide, the stability of cyclodextrin inclusion complexes is significantly improved and storage conditions are reduced.

[0051] Then, a hydrogel nasal formulation was prepared. 2.4 g of poloxamer 407, 0.1 g of poloxamer 188, and 0.3 g of hydroxypropyl methylcellulose were dissolved in 10 mL of pure water, mixed thoroughly with stirring on ice, and then allowed to swell at 4°C for 24 h. The prepared cyclodextrin inclusion complex was slowly added to the cooled hydrogel matrix, stirred thoroughly, and the pH was measured to be within the range of 5.5-6.5. Finally, the resulting mixture was filled into nasal containers to obtain the hydrogel nasal formulation based on the cyclodextrin inclusion complex.

[0052] from Figure 3 The morphological diagram shows that the nasal preparation is a uniformly dispersed and free-flowing injectable solution at low temperatures. When placed at nasal cavity temperature, the blank gel becomes a semi-solid, transparent and uniform, non-flowing, and has a certain degree of viscosity.

[0053] Animal experiments on the prepared nasal gel formulation revealed that, compared with drug molecules, the hydrogel had higher bioavailability in rat plasma and significantly improved indicators related to hypoxia-induced brain injury.

[0054] The hydrogel matrix, poloxamer, and ligustilide cyclodextrin inclusion complex were subjected to cold stirring and full swelling to enhance the interaction between the hydrogel and the nasal mucosa, resulting in a stable, homogeneous, and highly safe hydrogel formulation. Under simulated nasal conditions (pH=6.4, 34℃), the cumulative release rate of the hydrogel at 6 h was (60.84±1.40)%, and the cumulative release rate at 24 h was (90.69±2.16)%, conforming to the first-order fitting equation. Figure 4 As shown, compared with the drug ligustilide, the hydrogel increased the cumulative release rate in the medium simulating the pH environment of the nasal cavity by 1.55 times, which can effectively improve the in vitro dissolution rate of drug molecules, prolong the administration time, and improve drug utilization.

[0055] Pharmacokinetic studies of a thermosensitive hydrogel nasal formulation based on ligustilide cyclodextrin inclusion complex revealed that both the drug and hydrogel concentrations in plasma initially increased and then decreased. The drug peaked at 90 min, while the hydrogel peaked at 2 h, indicating that the hydrogel exhibits a slight sustained-release effect and higher bioavailability compared to LIG. Figure 5 As shown.

[0056] Tissue distribution studies of a thermosensitive hydrogel nasal formulation based on ligustilide cyclodextrin inclusion complex revealed that, 2 hours after administration, the hydrogel ligustilide accumulated in the heart, liver, spleen, lung, kidney, and brain tissues of rats. Quantitative analysis showed that the drug concentration in brain tissue was significantly higher than in other tissues, indicating a certain brain-targeting effect. Figure 6 As shown.

[0057] Pharmacodynamic studies of a thermosensitive hydrogel nasal formulation based on ligustilide cyclodextrin inclusion complex revealed that after nasal administration, the levels of IL-1β and TNF-α in the LIC-IC@Gel-M and LIC-IC@Gel-H groups were reduced by 10.43%, 10.72%, 12.90%, and 12.02%, respectively, compared to the HH group. The IL-6 level in the LIC-IC@Gel-M group was significantly reduced by 21.26% compared to the HH group. The MDA content in LIC-IC@Gel-M was significantly reduced by 29.16% compared to the HH group, while the GSH and SOD contents were significantly increased by 59.76% and 59.07%, respectively, compared to the HH group. Figure 7 As shown, the hydrogel had a more significant therapeutic effect compared with the drug group, nasal drops group, and spray group (P<0.05).

[0058] Example 3

[0059] First, the cyclodextrin inclusion complex was prepared. 10 g of hydroxypropyl-β-cyclodextrin was weighed and placed in a 50 mL beaker, dissolved in an appropriate amount of pure water. 1 g of ligustilide was accurately weighed, dissolved in 0.5 mL of anhydrous ethanol, and transferred to the beaker. The mixture was stirred for 3 h at 40 °C and 700 r / min using a magnetic stirrer. After stirring, the solution was filtered, the solid was collected, and freeze-dried at -48 °C for 4 h to obtain a white solid powder. This powder was washed with water, then washed three times with petroleum ether, and evaporated to a constant weight to obtain the cyclodextrin inclusion complex.

[0060] Then, a hydrogel nasal formulation was prepared. 24 g of poloxamer 407, 1 g of poloxamer 188, and 3 g of hydroxypropyl methylcellulose were dissolved in 100 mL of pure water, mixed thoroughly with stirring on ice, and then placed in a 4°C refrigerator for 24 h to swell. The prepared cyclodextrin inclusion complex was slowly added to the cooled hydrogel matrix, stirred thoroughly, and the pH value was measured to be within the range of 5.5-6.5. Finally, the resulting mixture was filled into nasal containers to obtain the hydrogel nasal formulation based on the cyclodextrin inclusion complex.

[0061] Example 4

[0062] 1. During the preparation of cyclodextrin inclusion complexes, when screening the core-wall mass ratio, the dosage was fixed at 0.2 g, and the mass ratios of ligustilide and HP-β-CD were 1:4, 1:6, 1:8, 1:12, and 1:14, respectively. The magnetic stirrer was set at 30℃ and 700 r / min, and the inclusion treatment lasted for 3 h.

[0063] 2. The experimental process was processed, and a comprehensive score was calculated. Within the range of 1:4-1:10, the comprehensive score increased with the increase of the HP-β-CD ratio, but then tended to decrease. This may be because when the ratio reached 1:10, the cavity of HP-β-CD was already saturated, and excess cyclodextrin tended to aggregate and agglomerate, affecting the inclusion effect. The three levels with the highest comprehensive scores—1:8, 1:10, and 1:12—were selected for process optimization. The scoring results are as follows: Figure 8 As shown.

[0064] 3. The Box-Behnken response surface methodology results were analyzed using Design-Expert 13.0.1 software. The optimal process, determined through computer fitting calculations, was a core-to-wall mass ratio of 1:10, an inclusion temperature of 40℃, an inclusion time of 3 h, and an inclusion rotation speed of 700 r / min. Under these conditions, the theoretical comprehensive score was 61.2. Three parallel experiments were conducted under these optimal conditions. The results of these three parallel experiments demonstrate that the optimal process obtained from the response surface methodology is stable and suitable for subsequent fabrication.

[0065] 4. In the preparation of hydrogel nasal formulations, based on the results of preliminary experiments, hydrogels were designed and prepared using P407 (20, 22, 24, 26, 28%), P188 (1, 1.5, 2, 2.5, 3%), and HPMC (1, 2, 3, 4, 5%) as the formulation. The gelation temperature and gelation time were investigated, and the results are as follows: Figure 9 As shown, the optimal preparation process was determined. Furthermore, considering the nasal cavity temperature and actual resource and energy consumption factors, a P407:P188 ratio of 24%:1% was selected. At this ratio, the gel temperature was (33.27±0.06)℃, and the gel time was (54.33±2.08)s, allowing for rapid formation of a semi-solid gel within the nasal cavity. The adhesive polymer HPMC primarily affects the gel time; as the HPMC concentration increases, the gel time shortens. However, excessive concentration can generate a large number of bubbles, affecting the full swelling of the hydrogel. Therefore, 3% HPMC was chosen.

[0066] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A thermosensitive hydrogel formulation for treating brain hypoxia-related disorders, characterized in that, The active ingredient of the formulation is ligustilide cyclodextrin inclusion complex, which is prepared by inclusion complex of ligustilide and hydroxypropyl-β-cyclodextrin. The mass ratio of ligustilide to hydroxypropyl-β-cyclodextrin in the ligustilide cyclodextrin inclusion complex is (1:4) to (1:14); preferably 1:

10.

2. The thermosensitive hydrogel formulation for treating hypoxia-related brain disorders according to claim 1, characterized in that, The preparation method of the ligustilide cyclodextrin inclusion complex is as follows: a specified amount of hydroxypropyl-β-cyclodextrin is dissolved in ultrapure water by stirring to obtain a hydroxypropyl-β-cyclodextrin solution; a specified amount of ligustilide is dissolved in an organic solvent to obtain a ligustilide solution. Under stirring conditions, the ligustilide solution was added to the hydroxypropyl-β-cyclodextrin solution for inclusion. After freeze-drying, the freeze-dried powder was washed with water, then washed with petroleum ether, and evaporated to a constant weight to obtain the ligustilide cyclodextrin inclusion complex.

3. The thermosensitive hydrogel formulation for treating hypoxia-related brain disorders according to claim 2, characterized in that, The organic solvent is anhydrous ethanol; the specific conditions for inclusion are an inclusion temperature of 40°C, an inclusion time of 3 h, and an inclusion rotation speed of 700 r / min.

4. The thermosensitive hydrogel formulation for treating hypoxia-related brain disorders according to claim 1, characterized in that, The hydrogel is obtained by dissolving poloxamer 407 and poloxamer 188 in ultrapure water, stirring on ice to dissolve, adding hydroxypropyl methylcellulose (HPMC) and stirring until homogeneous, and then refrigerating at 4°C overnight to obtain a clear and uniformly dispersed hydrogel solution.

5. The thermosensitive hydrogel formulation for treating hypoxia-related brain disorders according to claim 4, characterized in that, Based on the mass-volume ratio, the amount of poloxamer 407 added is 20%-28%, preferably 24%; the amount of poloxamer 188 added is 1%-3%, preferably 1%; and the amount of hydroxypropyl methylcellulose (HPMC) added is 1%-5%, preferably 3%.

6. The method for preparing a thermosensitive hydrogel formulation for treating hypoxia-related brain disorders according to any one of claims 1-5, characterized in that, Includes the following steps: Hydroxypropyl-β-cyclodextrin was dissolved in ultrapure water by stirring to obtain a hydroxypropyl-β-cyclodextrin solution; Dissolve the specified amount of ligustilide in an organic solvent to obtain a ligustilide solution; under stirring, add the ligustilide solution to a hydroxypropyl-β-cyclodextrin solution and stir to encapsulate it. After freeze-drying, the freeze-dried powder was washed with water, then washed with petroleum ether, and evaporated to a constant weight to obtain the ligustilide cyclodextrin inclusion complex. Poloxamer 407 and Poloxamer 188 were dissolved in ultrapure water and stirred on ice until dissolved. Hydroxypropyl methylcellulose (HPMC) was then added and stirred until homogeneous. The solution was then refrigerated at 4°C overnight to prepare a clear and uniformly dispersed thermosensitive hydrogel solution. The ligustilide cyclodextrin inclusion complex prepared in step S1 is dispersed in the thermosensitive hydrogel solution prepared in step S2, and the pH is adjusted to 5.5-6.5 to obtain a thermosensitive hydrogel formulation for treating hypoxia-related brain diseases.

7. The preparation method according to claim 6, characterized in that, In step S1, the mass ratio of ligustilide to hydroxypropyl-β-cyclodextrin is (1:4)-(1:14), preferably 1:10; the organic solvent is anhydrous ethanol; the specific inclusion conditions are an inclusion temperature of 40°C, an inclusion time of 3 h, and an inclusion rotation speed of 700 r / min.

8. The preparation method according to claim 6, characterized in that, In step S2, the amount of poloxamer 407 added is 20%-28%, preferably 24%; the amount of poloxamer 188 added is 1%-3%, preferably 1%; and the amount of hydroxypropyl methylcellulose (HPMC) added is 1%-5%, preferably 3%.

9. The use of the thermosensitive hydrogel formulation according to any one of claims 1-5 in the preparation of a medicament for targeted and precise treatment of brain tissue hypoxia.

10. The application according to claim 9, characterized in that, The drug is a nasal preparation.

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