Chitosan gel loaded with itraconazole as well as preparation method and application of chitosan gel

Abstract

The invention belongs to the technical field of biological medicines, and relates to itraconazole-loaded chitosan gel as well as a preparation method and application thereof. Comprising itraconazole and chitosan gel, the content of the itraconazole loaded on the chitosan gel is not lower than 0.300 mg / mL, and the chitosan gel is chemically crosslinked hydrogel which is formed by reacting chitosan with four-arm polyethylene glycol active ester through amino in the chitosan and NHS groups in the four-arm polyethylene glycol active ester to generate amido bonds. The aperture of the cross section of the hydrogel in the gel forming direction is 15-30 microns, and the cross section of the hydrogel in the direction perpendicular to the gel forming direction is of a lamellar structure. The itraconazole-loaded chitosan gel provided by the invention has an exact fibrosis inhibition effect, can stay in a uterine cavity for a long time, and has a certain mechanical support effect on the uterine cavity.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomedicine, and relates to a chitosan gel loaded with itraconazole, a preparation method thereof, and an application thereof. Background Art

[0002] Disclosing the information of this background art section is only intended to enhance the understanding of the overall background of the present invention, and is not necessarily regarded as an admission or an implication in any form that this information constitutes the prior art already known to those of ordinary skill in the art.

[0003] The standard treatment plan for intrauterine adhesion (IUA) is transcervical resection of adhesion (TCRA). However, the adhesion recurrence rate after surgery is relatively high. Currently, anti-adhesion measures after hysteroscopy applied in clinical practice include biological gels, physical barriers, cytokines, etc., but there is still a lack of a generally recognized effective prevention strategy. Hyaluronic acid hydrogel (HA) is widely used to prevent postoperative adhesions and assist in endometrial regeneration after hysteroscopic adhesion lysis. However, HA lacks the ability to inhibit the progression of fibrosis. Its characteristics of insufficient hardness and fast degradation rate limit its residence time in the uterine cavity and lack the mechanical support effect on the uterine cavity. The effectiveness of its anti-adhesion is still controversial. The Foley balloon has a good mechanical support effect on the uterine cavity, and its main treatment idea is to physically separate the uterine walls and prevent them from contacting each other, but it does not have the ability to inhibit the progression of endometrial fibrosis. According to the current research on the pathogenesis of intrauterine adhesions, endometrial fibrosis is the central link in the occurrence and development of this disease. Therefore, inhibiting fibrosis is an essential part of the measures to prevent adhesion recurrence. However, the two anti-fibrotic drugs (pirfenidone and nintedanib) approved by the FDA have not been used for the treatment of endometrial fibrosis. There are research reports that platelet-rich plasma and granulocyte colony-stimulating factor have the ability to inhibit the progression of fibrosis. Clinically, these two biological products are used to try to adopt the method of intrauterine perfusion to inhibit adhesion recurrence and fibrosis progression. However, the preparation process of biological products is complex, the price is high, there are biosafety risks, and the administration method of intrauterine perfusion makes the action time of them on the endometrium too short, and often requires repeated treatments, which increases the burden on patients. Therefore, the problems existing in current anti-adhesion drugs, such as the uncertain inhibitory effect on fibrosis, short residence time in the uterine cavity, insufficient mechanical support effect on the uterine cavity, complex preparation, high price, and biosafety risks, need to be solved urgently. Summary of the Invention

[0004] To solve the deficiencies of the prior art, the object of the present invention is to provide an itraconazole-loaded chitosan gel, its preparation method and application. The itraconazole-loaded chitosan gel provided by the present invention has an exact anti-fibrosis effect, a relatively long residence time in the uterine cavity, and a certain mechanical support effect on the uterine cavity.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] On the one hand, an itraconazole-loaded chitosan gel, comprising itraconazole and a chitosan gel. The content of itraconazole loaded in the chitosan gel is not less than 0.300 mg / mL. The chitosan gel is a hydrogel formed by chemical cross-linking of chitosan and 4-arm poly(ethylene glycol) NHS ester (4-arm-PEG-NHS) through the reaction of amino groups in chitosan with NHS groups in 4-arm poly(ethylene glycol) NHS ester to form amide bonds. The cross-sectional pore size of the hydrogel along the gelation direction is 15 - 30 μm, and the cross-section perpendicular to the gelation direction of the hydrogel shows a lamellar structure.

[0007] Previous studies of the present invention found that itraconazole (ITA) can reduce the fibrosis of human endometrial stromal cells (HESC) induced by transforming growth factor beta 1 (TGF-β1) by inhibiting the Hedgehog signaling pathway. Its anti-fibrotic effect is enhanced within a certain range with the increase of drug dose and action time. Intra-gastric administration of itraconazole can reduce the degree of endometrial fibrosis in rats with intrauterine adhesions. Itraconazole has been clinically used for more than twenty years, and the safety risks and adverse reactions of the drug have been fully evaluated, and its price is much lower than the current anti-fibrosis drugs, with the characteristics of economy and safety.

[0008] However, the inventors' research found that the lipophilic property of itraconazole makes it highly enriched in the skin, hair, and liver; at the same time, the anti-fungal treatment of itraconazole is mainly systemic administration, and its main dosage forms are capsules, dispersible tablets or oral liquids, with low targeting to the female reproductive system. These defects limit the treatment efficiency of itraconazole for endometrial fibrosis. The present invention uses a chitosan gel formed by chitosan and 4-arm poly(ethylene glycol) NHS ester to load itraconazole, which can be directly placed into the uterine cavity. It can not only improve the treatment efficiency of itraconazole for endometrial fibrosis, but also can stay in the uterine cavity for a long time, and has a certain mechanical support effect on the uterine cavity. In addition, the itraconazole-loaded chitosan gel provided by the present invention has good structural stability, which is beneficial for storage and transportation.

[0009] On the other hand, a method for preparing the above itraconazole-loaded chitosan gel is as follows: chitosan is added to an aqueous acetic acid solution and dissolved to form a chitosan solution; a hydroxide solution of an alkali metal is added to the chitosan solution to adjust the pH to 5-7; itraconazole is added to the chitosan solution with adjusted pH and mixed evenly to form a chitosan solution containing itraconazole; a tetra-arm polyethylene glycol active ester solution is added to the chitosan solution containing itraconazole, mixed evenly, and left to stand at room temperature until a gel is formed; the gel is immersed in a sodium hydroxide solution for soaking treatment to modify the gel; the modified gel is dialyzed to neutrality to obtain the product.

[0010] In a third aspect, the above itraconazole-loaded chitosan gel is used in the preparation of a drug for preventing intrauterine adhesions.

[0011] The beneficial effects of the present invention are as follows:

[0012] 1. The itraconazole-loaded chitosan gel provided by the present invention has an anti-fibrotic effect; through cell experiments, it is shown that it has an inhibitory effect on the fibrosis of HESC cells induced by 20 ng / ml TGF-β1, can significantly inhibit the production of type I collagen, a fibrosis marker, and has a certain inhibitory effect on the other two fibrosis markers, α-smooth muscle actin (α-SMA) and fibronectin 1 (FN1); through animal experiments, it is shown that the degree of endometrial fibrosis of the itraconazole-loaded chitosan gel is significantly lower than that of the uterus on the simple injury side; thus, it is proved that the itraconazole-loaded chitosan gel provided by the present invention has the effect of inhibiting endometrial fibrosis.

[0013] 2. The itraconazole-loaded chitosan gel provided by the present invention has an appropriate weight loss rate. In an in vitro degradation experiment at 37°C, the weight loss is about 40% in 30 days. And it can stably exist in the rat uterine cavity for more than 8 days. Compared with intrauterine perfusion, it can extend the intrauterine residence time of the drug by at least 500 times and does not require repeated treatment. Under the condition of 37°C, the gel can form a controlled release system of itraconazole, and the drug release rate can reach 60% within 4 days.

[0014] 3. The itraconazole-loaded chitosan gel provided by the present invention has excellent mechanical strength in a medium alkaline (pH = 7.5) environment, and the compressive strength can reach 0.47 MPa. When the itraconazole-loaded chitosan gel is placed into the abdominal cavity of a rat and the placed gel is recovered after 50 days, it is found that it can still maintain good mechanical strength, and the compressive strength can reach 0.29 MPa.

[0015] 4. The itraconazole-loaded chitosan gel provided by the present invention has a weight loss of about 16% after being stored at 4 °C for 210 days in a neutral (pH = 7.0) environment. Observed under a scanning electron microscope, its interior still presents a three-dimensional porous structure, and the pore size can still be maintained at 15 - 30 μm. Good storage stability is beneficial to the storage and transportation of the gel after commercial production.

[0016] 5. In the itraconazole-loaded chitosan gel provided by the present invention, the loaded itraconazole has been clinically applied for more than 20 years, and patients have good tolerance. Pregnant women's exposure to itraconazole during pregnancy does not significantly increase the risks of birth defects, stillbirths, and miscarriages, and it has high safety. At the same time, compared with pirfenidone and nintedanib, the selling price of itraconazole is lower and there is no need for import, which greatly reduces the production cost of the itraconazole-loaded chitosan gel. In addition, the collection of platelet-rich plasma is an invasive operation and its preparation requires the cooperation of a sterile laboratory. The itraconazole-loaded chitosan gel produced by the present invention can be used immediately after opening, which is convenient to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The specification drawings forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0018] Figure 1 is a schematic structural diagram of the itraconazole-loaded chitosan gel prepared for the present invention;

[0019] Figure 2 is the itraconazole-loaded chitosan gel observed by a stereomicroscope in the abdominal cavity of rats after 0, 16, and 50 days in the examples of the present invention;

[0020] Figure 3 is the microscopic structure of the unloaded chitosan gel and the itraconazole-loaded chitosan gel observed by an electron microscope and the microscopic structure after being placed in the abdominal cavity of rats for 16 and 50 days in the examples of the present invention;

[0021] Figure 4 is the electron microscope observation results of the itraconazole-loaded chitosan gel before and after being stored at 4 °C for 220 days in the examples of the present invention;

[0022] Figure 5 is the compression mechanics diagram of the unloaded chitosan gel and the itraconazole-loaded chitosan gel in the examples of the present invention;

[0023] Figure 6 is the drug release rate of the itraconazole-loaded chitosan gel in the examples of the present invention;

[0024] Figure 7It is the in vitro degradation mass change curve of the drug-free chitosan gel and the itraconazole-loaded chitosan gel in the embodiments of the present invention;

[0025] Figure 8 It is the FTIR spectral detection results of the chitosan solution and the cross-linked chitosan gel in the embodiments of the present invention;

[0026] Figure 9 It is the compression mechanical diagrams of the drug-free chitosan gel and the itraconazole-loaded chitosan gel in the embodiments of the present invention before being placed into the abdominal cavity of rats and 16 days and 50 days after being placed;

[0027] Figure 10 It is the effect of the conditioned medium of the itraconazole-loaded chitosan gel detected by Western Blot on the fibrosis of HESC cells induced by TGF-β1. A is the protein blot diagram, and B is the bar chart of the inhibition results of the fibrosis markers;

[0028] Figure 11 It is the effect of the conditioned medium of the itraconazole-loaded chitosan gel detected by immunofluorescence on the fibrosis of HESC cells induced by TGF-β1 (blue fluorescence: DAPI; green fluorescence: α-SMA; red fluorescence: FN1). Scale bar: 20 μm;

[0029] Figure 12 It is the effect of the drug-free chitosan gel and the itraconazole-loaded chitosan gel on the endometrial fibrosis of the intrauterine adhesion rat model detected by Masson staining in the embodiments of the present invention. Detailed implementation manners

[0030] It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0031] It should be noted that the terms used herein are only for describing specific implementation manners and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0032] In view of the problems existing in the existing anti-adhesion drugs, such as the inaccurate inhibition effect of fibrosis, short residence time in the uterine cavity, insufficient mechanical support effect on the uterine cavity, complex preparation, high price, and biological safety risks, the present invention proposes a chitosan gel loaded with itraconazole, its preparation method and application.

[0033] A typical embodiment of the present invention provides a chitosan gel loaded with itraconazole, which includes itraconazole and a chitosan gel. The content of itraconazole loaded in the chitosan gel is not less than 0.300 mg / mL. The chitosan gel is a hydrogel formed by chemical crosslinking of chitosan and 4-arm polyethylene glycol active ester (4-arm-PEG-NHS) through the reaction of amino groups in chitosan with NHS groups in the 4-arm polyethylene glycol active ester to form amide bonds. The pore size of the cross-section of the hydrogel along the gel-forming direction is 15 - 30 μm, and the cross-section of the hydrogel perpendicular to the gel-forming direction presents a lamellar structure.

[0034] In some embodiments, the porosity of the chitosan gel is 30 - 35%.

[0035] In some embodiments, the mass ratio of chitosan, itraconazole, and 4-arm polyethylene glycol active ester is 10:0.25 - 0.30:8 - 12.

[0036] Another embodiment of the present invention provides a preparation method of the above-mentioned chitosan gel loaded with itraconazole. Chitosan is added to an acetic acid aqueous solution and dissolved to form a chitosan solution; an alkali metal hydroxide solution is added to the chitosan solution to adjust the pH to 5 - 7; itraconazole is added to the chitosan solution after adjusting the pH and mixed evenly to form a chitosan solution containing itraconazole; the 4-arm polyethylene glycol active ester solution is added to the chitosan solution containing itraconazole, mixed evenly, and left to stand at room temperature until a gel is formed; the gel is immersed in the alkali metal hydroxide solution for soaking treatment to modify the gel; the modified gel is dialyzed to neutrality to obtain the product.

[0037] First, chitosan dissolves under acidic conditions, but when the pH is too low, the amino groups on chitosan will be protonated (-NH3 + +), and the reaction activity decreases. In the present invention, the pH of the chitosan solution is adjusted to 5 - 7 to improve the reaction activity of amino groups on the premise of ensuring complete dissolution of chitosan, thereby improving the crosslinking reaction efficiency.

[0038] The optimal reaction conditions for 4-arm polyethylene glycol active ester and amino groups are alkaline. However, due to the special solubility of chitosan, the synthesized chitosan hydrogel is an acidic system after synthesis. Therefore, it contains more protonated amino groups (-NH3+), and there are more ionic repulsions between molecular chains. The synthesized hydrogel has very poor mechanical strength and is very easy to break. Therefore, an alkali metal hydroxide is selected to modify it. The treatment with an alkali metal hydroxide can neutralize the protonated amino groups in the hydrogel, eliminate the ionic repulsions between molecular chains, greatly improve the mechanical strength of the hydrogel, adjust the physical properties of the gel, and stabilize the gel structure, making it more suitable for use as a biological scaffold material.

[0039] In some embodiments, the concentration of the aqueous acetic acid solution is 0.5-1.5%, and the concentration of chitosan in the chitosan solution is 9-11 mg / ml.

[0040] In some embodiments, the chitosan solution is heated to 50-70 °C and stirred until the chitosan is completely dissolved, and the insoluble impurities are removed by filtration.

[0041] In some embodiments, the mass ratio of chitosan to tetra-arm polyethylene glycol active ester is 1:0.8-1.2.

[0042] In some embodiments, the time for standing at room temperature until the gel is formed is 20-30 min.

[0043] In some embodiments, in the soaking treatment, the concentration of the sodium hydroxide solution is 0.8-1.2 mol / L.

[0044] In some embodiments, the soaking time is 50-70 min.

[0045] In some embodiments, the dialysis time is 12-24 h.

[0046] The third embodiment of the present invention provides an application of the above-mentioned itraconazole-loaded chitosan gel in the preparation of a drug for preventing intrauterine adhesions.

[0047] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0048] Example

[0049] A method for preparing an itraconazole-loaded chitosan gel: The steps are as follows:

[0050] 1. Prepare an acetic acid solution with a concentration of 1% (v / v) using distilled water, and add chitosan powder to prepare a chitosan solution with a concentration of 10 mg / ml.

[0051] 2. Heat the chitosan solution in a water bath to 60 °C, stir with a magnetic stirrer for 1 h until the chitosan powder is completely dissolved, and filter using a 1000-mesh nylon cloth to remove insoluble impurities.

[0052] 3. Dropwise add 1 mol / L NaOH solution to the solution, and adjust the pH of the chitosan solution to 6.

[0053] 4. Add itraconazole powder to the chitosan solution, and stir magnetically until it is evenly dispersed to prepare a chitosan solution with an itraconazole concentration of 0.282 mg / ml.

[0054] 5. Inject the itraconazole-containing chitosan solution into a mold.

[0055] 6. Add the crosslinker 4-arm-PEG-NHS with a concentration of 100 mg / ml to the chitosan solution containing itraconazole at a volume ratio of 1 / 10. During this process, continuously stir with a stirring rod to ensure uniform mixing of the two.

[0056] 7. Let it stand at room temperature for 25 min until the above mixed solution loses fluidity and forms a gel.

[0057] 8. Immerse the gel in 1 mol / L NaOH solution for 1 h for modification.

[0058] 9. Then immerse the gel in ultrapure water for 24 h for dialysis until the gel is dialyzed to neutral.

[0059] The structural schematic diagram of the itraconazole-loaded chitosan gel prepared in this example is as Figure 1 shown.

[0060] 4-arm-PEG-NHS crosslinks chitosan into a gel as a crosslinker, and itraconazole is loaded in the voids of the gel. The infrared spectrum is as Figure 8 shown.

[0061] The preparation method of the chitosan gel without loading itraconazole is as described above, with the difference that: step 4 is omitted.

[0062] The chitosan gel without loading itraconazole prepared in this example is as Figure 3 shown, presenting a three-dimensional porous structure inside. The pore size of the cross-section along the gel-forming direction is about 15 - 30 μm, and the porosity is 33.18%; the cross-section perpendicular to the gel-forming direction presents a lamellar structure and is a good drug delivery carrier.

[0063] The itraconazole-loaded chitosan gel prepared in this example is stored at 4 °C for 210 days in a neutral (pH = 7.0) environment, and its weight loss is about 16%. Observed under a scanning electron microscope, its internal structure still presents a three-dimensional porous structure, and the pore size can still be maintained at 15 - 30 μm, as Figure 4 shown. Good storage stability is beneficial to the storage and transportation after the commercial production of this gel.

[0064] As Figure 5 shown, the itraconazole-loaded chitosan gel prepared in this example has excellent mechanical strength in a neutral to alkaline (pH = 7.5) environment, and the compressive strength reaches 0.47 MPa.

[0065] Place the itraconazole-loaded chitosan gel into the abdominal cavity of rats. After 50 days, recover the placed gel and find that it can still maintain good mechanical strength, and the compressive strength reaches 0.29 MPa, as Figure 9 shown.

[0066] In vitro drug release experiments were carried out on itraconazole-loaded chitosan gels. It was found that at 37 °C, the gel could form a controlled release system for itraconazole, and the drug release rate could reach 60% within 4 days, as Figure 6 shown. As a result, the concentration of itraconazole should not be less than 2 μM. Combining the results of the itraconazole release experiment of the chitosan gel, the itraconazole drug content loaded in the chitosan gel was adjusted to 0.282 mg / ml.

[0067] The itraconazole-loaded chitosan gel prepared in this example had an appropriate weight loss rate. In the in vitro degradation experiment at 37 °C, the weight loss was about 40% in 30 days, as Figure 7 shown.

[0068] The itraconazole-loaded chitosan gel was placed into the uterine cavity of rats to detect the degradation rate of the gel in the animal body. It was found that it could stably exist in the uterine cavity of rats for more than 8 days. Compared with intrauterine perfusion, it could extend the intrauterine residence time of the drug by at least 500 times and did not require repeated treatment.

[0069] 300 mg of itraconazole-loaded chitosan gel was placed into the abdominal cavity of rats to detect the degradation rate of the gel in the animal body. It was found that it could stably exist in the abdominal cavity of rats for more than 40 days, and the weight loss was about 50% in 40 days, as Figures 2 - 3 shown.

[0070] Cell experiments were carried out on the anti-fibrotic effect of itraconazole-loaded chitosan gels. HESC cells were cultured with the conditioned medium of itraconazole-loaded chitosan gels. Through Western Blot and immunofluorescence detection, it was found that it had an inhibitory effect on the fibrosis of HESC cells induced by 20 ng / ml TGF-β1, could significantly inhibit the production of the fibrosis marker - type I collagen (Collagen I), and had a certain inhibitory effect on the other two fibrosis markers - α-smooth muscle actin (Smoothmuscle actin, α-SMA) and fibronectin 1 (Fibronectin 1, FN1), as Figures 10 - 11 shown.

[0071] Animal experiments were carried out on the anti-fibrotic effect of itraconazole-loaded chitosan gel. In this study, a rat intrauterine adhesion model was constructed by mechanical injury method. Female SD rats aged 8-10 weeks were captured and weighed with an electronic balance. Anesthesia was induced by intraperitoneal injection of 1.5% sodium pentobarbital solution, and the drug injection dose was determined according to the animal weight, generally 2 ml / kg. After the rats were completely anesthetized, they were placed on the animal operating table, in the supine position, and their limbs and heads were fixed with cotton threads. The hair on the lower abdomen of the rats was shaved off with a hair clipper. The area was disinfected once with an iodophor cotton swab and then once with a cotton swab dipped in 75% ethanol, and a sterile surgical drape was laid. Starting from 0.5 cm above the pubic symphysis, a midline abdominal incision was made along the abdominal wall midline in the cephalad direction with an ophthalmic scissors, and the incision length was about 2.5 cm. The skin, muscle, and peritoneum were incised to expose the uterus. One uterine horn of the rat was exposed, and starting from 0.5 cm from the uterine bifurcation, a 1.5-cm-long longitudinal incision was made along the long axis of one uterine horn in the direction of the ovary with a microsurgical scissors to expose the endometrium, and the endometrial layer was scraped off with a surgical blade. After the curettage operation, the uterine cavity and abdominal cavity were rinsed with sterile normal saline, and the excess fluid was aspirated with sterile gauze. A mold simulating the shape of the rat uterine cavity was used to prepare unloaded / itraconazole-loaded chitosan gel, which was then placed into the injured rat uterine cavity. The uterus was sutured with 7-0 absorbable suture (with needle). The muscle and abdominal wall were sutured with 5-0 silk thread using continuous suture method, and the skin was sutured with 4-0 silk thread using simple interrupted suture method. After the operation, the rats were sent back to the cage. After modeling, the rat uterine specimens were collected, and cross-sectional pathological sections of the rat uterus were prepared. Through immunofluorescence and Masson staining detection, it was found that the degree of endometrial fibrosis in the uterus implanted with itraconazole-loaded chitosan gel was significantly lower than that of the uterus on the simple injury side, as Figure 12 shown.

[0072] This proved that itraconazole-loaded chitosan gel has the effect of inhibiting endometrial fibrosis, and its effect is significantly better than that of using chitosan gel alone.

[0073] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A chitosan gel loaded with itraconazole, characterized in that: The invention comprises itraconazole and chitosan gel, wherein the content of itraconazole loaded in the chitosan gel is not less than 0.300 mg / mL, and the chitosan gel is a chemically cross-linked hydrogel formed by the reaction of chitosan and four-arm polyethylene glycol active ester through the amino group in the chitosan and the NHS group in the four-arm polyethylene glycol active ester to form amide bonds, the cross-sectional pore diameter of the hydrogel along the gelation direction is 15 to 30 μm, and the cross-section of the hydrogel perpendicular to the gelation direction presents a lamellar structure.

2. The itraconazole-loaded chitosan gel according to claim 1, characterized in that: The porosity of the chitosan gel is 30-35%; Or, the mass ratio of chitosan, itraconazole and four-arm polyethylene glycol active ester is 10:0.25-0.30:8-12.

3. A method for preparing the itraconazole-loaded chitosan gel according to claim 1, characterized in that: Chitosan is added into an acetic acid aqueous solution to dissolve, so as to prepare a chitosan solution; an alkali metal hydroxide solution is added into the chitosan solution to adjust the pH value to 5-7; itraconazole is added into the chitosan solution after the pH value is adjusted, and the mixture is mixed evenly, so as to prepare a chitosan solution containing itraconazole; a four-arm polyethylene glycol active ester solution is added into the chitosan solution containing itraconazole, the mixture is mixed evenly, and the mixture is allowed to stand at room temperature until a gel is formed; the gel is immersed into a sodium hydroxide solution for immersion treatment, so as to modify the gel; and the modified gel is dialyzed until it is neutral, so as to obtain the obtained product.

4. The method for preparing the itraconazole-loaded chitosan gel according to claim 3, characterized in that: The concentration of the acetic acid aqueous solution is 0.5-1.5%, and the concentration of chitosan in the chitosan solution is 9-11 mg / ml.

5. The method for preparing the itraconazole-loaded chitosan gel according to claim 3, characterized in that: The chitosan solution is heated to 50-70°C and stirred until the chitosan is completely dissolved, and then filtered to remove insoluble impurities.

6. The method for preparing the itraconazole-loaded chitosan gel according to claim 3, characterized in that: The mass ratio of chitosan to four-arm polyethylene glycol active ester is 1:0.8-1.

2.

7. The method for preparing the itraconazole-loaded chitosan gel according to claim 3, characterized in that: The time for standing at room temperature to form a gel is 20 to 30 minutes.

8. The method for preparing itraconazole-loaded chitosan gel according to claim 3, characterized in that: In the soaking treatment, the concentration of the sodium hydroxide solution is 0.8-1.2 mol / L; Alternatively, the soaking treatment time is 50 to 70 minutes.

9. The method for preparing itraconazole-loaded chitosan gel according to claim 3, characterized in that: The dialysis time is 12 to 24 hours.

10. Use of the itraconazole-loaded chitosan gel according to claim 1 or 2 in the preparation of a drug for preventing intrauterine adhesions.

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