Glioglucagon-like peptide-1 receptor stimulant-loaded silk fibroin microneedle patch and preparation method thereof

Abstract

The invention discloses a high glucagon-like peptide-1 receptor stimulant-loaded silk fibroin microneedle patch, which comprises a plurality of microneedles, each microneedle sequentially comprises a skin layer, a core layer and a base, the skin layer comprises silk fibroin and a structure regulator, the core layer comprises a water-soluble polymer compound and a high glucagon-like peptide-1 receptor stimulant, and the base comprises a water-soluble polymer compound and a high glucagon-like peptide-1 receptor stimulant. The base comprises silk fibroin which is insoluble in water; the cortex is the outermost part of the tip of the microneedle and is used for contacting a user and puncturing the skin during use, and the base is arranged on one side, far away from the tip, of the microneedle. According to the silk fibroin microneedle patch disclosed by the invention, by adding the structure regulator, the cortex silk fibroin has a SilkI crystal structure, and high swelling and low dissolution loss of the cortex are realized. Due to the cavity core layer structure of the skin-core layer, the storage space of the medicine is increased, the loading capacity of the medicine is improved, and in addition, the direct contact between the medicine high glucagon-like peptide-1 receptor agonist and the silk fibroin is also avoided.

Description

Technical Field

[0001] The present invention belongs to the technical fields of transdermal drug delivery and silk fibroin microneedle technology, and particularly relates to a silk fibroin microneedle patch with a skin-core layer structure loaded with glucagon-like peptide-1 receptor agonist and a preparation method of the skin-core layer silk fibroin microneedle patch. Background Art

[0002] Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease, mainly manifested as insulin resistance and decreased pancreatic β-cell function.

[0003] GLP-1 (glucagon-like peptide-1) is an important incretin hormone secreted by ileal and colonic cells, which has a significant effect on regulating blood glucose and reducing appetite, showing the potential for treating T2DM. GLP-1 enhances insulin secretion in a glucose concentration-dependent manner by activating the GLP-1 receptor, inhibits glucagon secretion, and can delay gastric emptying, reducing food intake through central appetite suppression, thereby achieving the effects of lowering blood glucose and losing weight. Due to the rapid degradation by DPP-4 (dipeptidyl peptidase-4) and renal clearance, the blood half-life of GLP-1 is extremely short, only 2 minutes, which limits its potential as a diabetes treatment drug. To address this limitation, researchers added a C16 fatty acid side chain at the 26th position of GLP-1, thus developing a glucagon-like peptide-1 receptor agonist (GLP-1RA). GLP-1RA not only continues the glucose-dependent hypoglycemic function of GLP-1 but also prolongs the residence time of the drug in the body, achieving long-term treatment.

[0004] Most of the current glucagon-like peptide-1 receptor agonist preparations on the market are mainly in injection form, which not only brings pain and inconvenience to patients during injection but also increases the storage and transportation costs and drug prices due to their high requirements for cold-chain transportation and storage. Injection administration can cause the blood drug concentration in the body to rapidly reach a peak in a short time, resulting in gastrointestinal adverse reactions such as nausea in patients. Long-term high-concentration exposure may induce pancreatitis and even pose a potential risk of pancreatic cancer. These side effects greatly affect the treatment experience and safety of patients. Although the emergence of oral preparations such as semaglutide provides new options for patients, the problems of high price and low bioavailability still limit their widespread application.

[0005] As an important branch of modern transdermal drug delivery technology, microneedle technology not only achieves painless and convenient drug administration but also demonstrates excellent drug delivery efficiency. In the existing Chinese technology, Chinese invention patent CN202310188371.6 discloses a liraglutide microneedle patch and its preparation method. In this invention, polyvinyl alcohol is mainly used as the microneedle skeleton material, and its microneedles are soluble type, resulting in the microneedle drug administration reaching the peak blood drug concentration even faster than injection drug administration, making it unable to avoid the related side effects brought by injection drug administration.

[0006] As a natural biomedical material with excellent biocompatibility and mechanical properties, silk fibroin has attracted extensive attention in the field of drug delivery systems in recent years. Through ingenious external intervention, scientists have successfully endowed silk fibroin with unique swelling properties, which provides new possibilities for realizing transdermal sustained release of drugs.

[0007] The disclosure of the above background technical content is only used to assist in understanding the inventive concept and technical solution of the present invention, and it does not necessarily belong to the prior art of this patent application. Without clear evidence indicating that the above content was publicly available before the filing date of this patent application, the above background technology should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0008] In view of this, in order to overcome the defects of the prior art, the purpose of the present invention is to provide a silk fibroin microneedle patch loaded with glucagon-like peptide-1 receptor agonist, using the structural regulator proline to induce silk fibroin to form a stable crystal structure, and preparing a silk fibroin skin-core layer microneedle loaded with glucagon-like peptide-1 receptor agonist with sustained release performance.

[0009] To achieve the above purpose, the present invention adopts the following technical solutions:

[0010] A silk fibroin microneedle patch loaded with glucagon-like peptide-1 receptor agonist, comprising a plurality of microneedles. Each microneedle sequentially includes a cortex, a core layer, and a base. A cavity for accommodating the core layer is formed between the cortex and the base. The cortex includes silk fibroin and a structural regulator. The core layer includes a water-soluble high molecular compound and a glucagon-like peptide-1 receptor agonist. The base includes silk fibroin and a structural regulator; the cortex is the outermost part of the microneedle tip, which is used to contact the user and pierce the skin during use, and the base is the side of the microneedle away from the tip.

[0011] The structural regulator is used to enable the silk fibroin in the cortex to form a stable SilkⅠcrystalline structure, so as to have the advantages of high swelling and low dissolution loss. The glucagon-like peptide-1 receptor agonist in the core layer is solid when not in use to avoid binding to silk fibroin. After the microneedle penetrates the skin, body fluid enters the core layer through the cortex, the water-soluble polymer compound dissolves, and the glucagon-like peptide-1 receptor agonist returns to the free state after contacting water, and then is released through the swelling network of silk fibroin in the cortex and enters the human body. The base is used to seal the core layer and needs to be insoluble in water. After the microneedle penetrates the skin, the core layer absorbs water and dissolves to form a hydrogel-like state. The base is insoluble in water and together with the cortex constructs a cavity containing the drug in the core layer. The base needs to prevent the core layer from overflowing the microneedle after dissolution.

[0012] According to some preferred embodiments of the present invention, the mass of the glucagon-like peptide-1 receptor agonist in the core layer is 2%-10% of the mass of the water-soluble polymer compound.

[0013] According to some preferred embodiments of the present invention, the glucagon-like peptide-1 receptor agonist is one or more selected from semaglutide, liraglutide, and tirzepatide.

[0014] According to some preferred embodiments of the present invention, the mass of the structural regulator in the cortex and the base is 10-40% of the mass of the silk fibroin. Preferably, the mass ratio of the structural regulator in the base is greater than that in the cortex to promote the drug to flow into the human body. Specifically, the mass of the structural regulator in the cortex is 10-35% of the mass of the silk fibroin, and the mass of the structural regulator in the base is 30-40% of the mass of the silk fibroin.

[0015] According to some preferred embodiments of the present invention, the structural regulator is one or more selected from proline, sorbitol, and xylitol. Preferably, the structural regulator is proline.

[0016] According to some preferred embodiments of the present invention, the water-soluble polymer compound is one or more selected from polyanionic compounds: sodium hyaluronate, sodium carboxymethylcellulose, sodium alginate, and sodium carboxymethyl starch. The water-soluble polymer compound is used to form a liquid with a certain viscosity to uniformly and stably disperse and encapsulate the glucagon-like peptide-1 receptor agonist such as liraglutide drug, and smoothly enter the cavity of the microneedle cortex during the preparation process. Preferably, the water-soluble polymer compound is sodium hyaluronate.

[0017] Preferably, during the preparation process, the viscosity of the gel-like liquid formed by the core layer solution containing the water-soluble polymer compound is 0.5 Pa·s - 5 Pa·s (25°C) to enable the core layer solution to smoothly enter the cavity to complete the preparation of the product.

[0018] Preferably, after preparation, when the product is used, the viscosity of the core layer after water absorption is 10 Pa·s - 100 Pa·s (37 °C). The high viscosity can prevent the softening of the silk fibroin cortex, reduce the strength of the whole microneedle, and the microneedle can be pulled out after use to prevent the residue of the microneedle substrate in the body. At the same time, the high viscosity can encapsulate GLP-1RA and achieve uniform dispersion, and further slow down the drug release rate to achieve a sustained release effect.

[0019] However, too high viscosity will also hinder the release of macromolecular drugs. Therefore, an anionic polymer is needed to form a repulsive force with the negatively charged glucagon-like peptide-1 receptor agonist to help the glucagon-like peptide-1 receptor agonist release.

[0020] According to some preferred embodiments of the present invention, the height of the microneedles in the silk fibroin microneedle patch is 300 - 1000 μm, the base diameter is 200 - 500 μm, and the spacing between adjacent needle tips is 200 - 1000 μm. More preferably, the height of the microneedles in the silk fibroin microneedle patch is 300 - 600 μm, the base diameter is 200 - 400 μm, and the spacing between adjacent needle tips is 300 - 600 μm. The microneedle patch presents a microneedle array in a conical shape.

[0021] The present invention also provides a preparation method of the silk fibroin microneedle patch loaded with glucagon-like peptide-1 receptor agonist as described above, including the following steps:

[0022] Dissolve the structural regulator in water and mix it with the silk fibroin solution to obtain the cortex solution;

[0023] Pour the cortex solution into a mold, defoam, and dry it under constant temperature, constant humidity and air convection conditions to obtain the cortex of the microneedles;

[0024] Dissolve the glucagon-like peptide-1 receptor agonist in water and mix it with the water-soluble polymer compound to obtain the core layer solution;

[0025] Pour the core layer solution into the cortex of the microneedles, defoam, and dry it under constant temperature and constant humidity to obtain the core layer of the microneedles;

[0026] Dissolve the structural regulator in water and mix it with the silk fibroin solution to obtain the base solution;

[0027] Pour the base solution on the side of the microneedle away from the needle tip, dry it to obtain the base, and demold to obtain the silk fibroin core-shell microneedle patch.

[0028] According to some preferred embodiments of the present invention, the concentration of the water-soluble polymer compound in the core layer solution is 1 - 10 wt%.

[0029] According to some preferred implementation aspects of the present invention, the concentration of silk fibroin in the cortical solution is less than that in the base solution. Preferably, the concentration of silk fibroin in the cortical solution is 5 - 20 mg / mL; the concentration of silk fibroin in the base solution is 20 - 200 mg / mL. The lower concentration of the cortex will shrink during drying to form a hollow cavity in the middle. The higher concentration of silk fibroin in the base facilitates rapid drying and forming, reducing the time of drug exposure to air.

[0030] In some embodiments, a method for preparing a silk fibroin core - shell micro - needle patch, using silk fibroin as the base material, includes the following steps:

[0031] S1. Preparation of the cortical solution: Dissolve the structure regulator in water and mix it with the silk fibroin solution to obtain the cortical solution. The concentration of silk fibroin in the cortical solution is 5 - 20 mg / mL.

[0032] S2. Preparation of the micro - needle cortex: Pour the prepared cortical solution evenly onto a polydimethylsiloxane mold, remove air bubbles under vacuum, and dry it in a constant temperature and humidity chamber under air convection for 6 - 12 h to obtain the cortical part of the micro - needles.

[0033] S3. Preparation of the core solution: Dissolve the glucagon - like peptide - 1 receptor agonist in water and mix it with the water - soluble polymer compound to obtain the core solution.

[0034] S4. Preparation of the core: Pour the core solution into the cortex of the micro - needles, remove air bubbles under vacuum, and place it in a constant temperature and humidity chamber to dry for 4 - 8 h to obtain the micro - needles with the core loaded in the cortex.

[0035] S5. Preparation of the base solution: Dissolve the structure regulator in water and mix it with the silk fibroin solution to obtain the base solution. The concentration of silk fibroin in the base solution is 20 - 200 mg / mL. Preferably, the mass ratio of the structure regulator in the base is greater than that in the cortex.

[0036] S6. Preparation of the micro - needle base: Pour the base solution on the side of the micro - needles away from the tips, dry it at 30 - 60 °C for 3 - 10 h to obtain the base, and demold to obtain the silk fibroin core - shell micro - needles.

[0037] The principle of the present invention is as follows: The molecular structure of the glucagon - like peptide - 1 receptor agonist is relatively special. It has added long fatty acid chains at different amino acid series positions, having certain surface activity to improve its binding ability with albumin. However, these hydrophobic structures containing fatty acid side chains also cause interactions with the hydrophobic regions of silk fibroin, forming strong binding, thus making it difficult to be released from the silk fibroin micro - needles in a free form. The silk fibroin micro - needles with a core - shell structure in this application solve this problem well.

[0038] The specific details are as follows:

[0039] The silk fibroin microneedles with a core-shell structure store the glucagon-like peptide-1 receptor agonist in the cavity of the microneedles without direct contact with the silk fibroin molecules. To reduce the binding force between the glucagon-like peptide-1 receptor agonist and the molecules, the present invention selects an anionic polymer solution as its dispersant. The glucagon-like peptide-1 receptor agonist carries a negative charge and forms a repulsive interaction with the anionic polymer, and the mutual force is relatively weak, which will not affect the drug release process of the glucagon-like peptide-1 receptor agonist. After constructing a relatively rigid microneedle cortex with silk fibroin, the glucagon-like peptide-1 receptor agonist dispersed in the anionic polymer solution is added to the cavity. The viscosity of the anionic polymer solution is relatively large, which limits the movement speed of the glucagon-like peptide-1 receptor agonist, making the number of molecules binding to silk fibroin limited. Moreover, the form of the cavity and the solid drug greatly increases the drug loading capacity. In addition, it also reduces the binding between it and silk fibroin, which helps to improve the drug delivery efficiency. The silk fibroin in the cortex structure forms a stable hydrophilic SilkⅠcrystalline structure under the action of the structure regulator, rather than a Silk II crystalline structure with certain hydrophobicity. In this way, after the microneedles penetrate the skin, the silk fibroin in the cortex swells under the action of body fluid to form a hydrophilic swelling network. The glucagon-like peptide-1 receptor agonist has a large interaction force with the hydrophobic structure and a small interaction force with the hydrophilic structure, and can be relatively easily released from the pores constructed by the hydrophilic SilkⅠcrystalline structure. Subsequently, the body fluid enters the cavity through the cortex, and the soluble polymer absorbs water and swells to form a high-viscosity hydrogel state. The glucagon-like peptide-1 receptor agonist comes into contact with water molecules and also resumes its free state with a negative charge. The glucagon-like peptide-1 receptor agonist molecule carries a negative charge and has a certain repulsive force with the anionic polymer, and can be released relatively quickly from the high-viscosity hydrogel system of the anionic polymer. Then it is released through the swelling network constructed by the silk fibroin SilkⅠcrystalline structure of the cortex. Due to the limited surface area of the silk fibroin swelling network, the contact amount with the glucagon-like peptide-1 receptor agonist molecules is also limited. It can only retard the speed of the glucagon-like peptide-1 receptor agonist passing through the swelling network and will not cause the glucagon-like peptide-1 receptor agonist to adsorb on the hydrophobic structure of the silk fibroin molecule and be difficult to release.

[0040] Due to the above technical solutions, the present invention has the following beneficial effects compared with the prior art: The silk fibroin microneedle patch loaded with glucagon-like peptide-1 receptor agonist of the present invention enables the glucagon-like peptide-1 receptor agonist to stably release into the body through the network of the hydrophilic silk fibroin SilkⅠcrystalline structure in the cortex from the core layer by the addition of an anionic polymer. The swellable microneedles reduce the risk of fracture residue after piercing the skin, prolong the maintenance time of the nano-pores, and ensure the long-term drug delivery. The cavity core layer structure of the skin-core layer increases the drug storage space, improves the drug loading capacity, and also avoids the problem that the glucagon-like peptide-1 receptor agonist is difficult to release due to direct contact with silk fibroin molecules. The network of the silk fibroin SilkⅠcrystalline structure constructs the drug release cortex, and the high-viscosity anionic polymer constructs the sustained-release core layer. The two work together to enable the glucagon-like peptide-1 receptor agonist to achieve transdermal slow delivery for 24 hours. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0042] Figure 1 It is a schematic cross-sectional structure diagram of a single microneedle in the silk fibroin microneedle patch loaded with glucagon-like peptide-1 receptor agonist in Embodiment 1 of the present invention, where 1 is the cortex, 2 is the core layer, and 3 is the base;

[0043] Figure 2 It is the in vitro transdermal drug release curve of the liraglutide-loaded microneedles in Embodiments 3-8 and Comparative Example 1 of the present invention;

[0044] Figure 3 It is the blood drug concentration curve of rats in Embodiment 3 and Comparative Example 2 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0046] The preparation method of the core-shell layer fibroin micro-needle patch skin of the present invention uses domestic silkworm silk as raw material, and obtains fibroin solution through degumming, lithium bromide dissolution, dialysis and purification, including the following steps:

[0047] S1. Preparation of cortex solution

[0048] Weigh a structural regulator, whose mass is 10-35% of the mass of fibroin, dissolve it in water and mix it with the fibroin solution to obtain a cortex solution, ensuring that the concentration of fibroin in the cortex solution is 5-20mg / mL.

[0049] S2. Preparation of micro-needle cortex

[0050] Pour the prepared cortex solution evenly on a polydimethylsiloxane mold. To ensure the uniformity and integrity of the micro-needle structure, it is necessary to evacuate to a vacuum degree of -0.09 Mpa in a vacuum drying oven and repeat the evacuation 3 times to fully discharge the air in the mold. Then, place the mold in a constant temperature and humidity room and dry it for 6-12h under the condition of convective air to completely dry and solidify the cortex solution, obtaining the cortex part of the micro-needle and forming the cortex of the micro-needle.

[0051] S3. Preparation of core solution

[0052] Weigh a glucagon-like peptide-1 receptor agonist drug at 2-10% of the mass of fibroin in the cortex, dissolve it in water and mix it with a water-soluble polymer compound to obtain a core solution. The concentration of the water-soluble polymer compound in the core solution is 1-10wt%.

[0053] S4. Preparation of micro-needle core

[0054] Pour the prepared core solution evenly into the cavity of the above-mentioned dried micro-needle cortex, evacuate 3 times in a vacuum drying oven, scrape off the bubbles after taking it out, and continuously repeat the above steps 3 times. Then place it in a constant temperature and humidity room and dry it for 4-8h to obtain a micro-needle loaded with the core layer.

[0055] S5. Preparation of base solution

[0056] Dissolve the structural regulator in water and mix it with the fibroin solution to obtain a base solution. The concentration of fibroin in the base solution is 20-200mg / mL. And preferably, the mass ratio of the structural regulator in the base is greater than that in the cortex. In this application, the mass ratio of the structural regulator in the base is 30-40% of the mass of fibroin.

[0057] S6. Preparation of micro-needle base

[0058] The base solution is evenly poured on the side of the microneedle away from the tip and placed in a constant temperature and humidity chamber at 30-60 °C for drying for 3-10 h to serve as the base part of the drug-loaded microneedle. After ensuring complete drying, the drug-loaded silk fibroin core-shell microneedles can be demolded.

[0059] Example 1 Structure of Silk Fibroin Microneedles

[0060] As Figure 1 shown, the silk fibroin microneedle patch loaded with glucagon-like peptide-1 receptor agonist of the present application, each microneedle patch includes a microneedle array of 15×15 presenting a cone shape. The height of the microneedles is 500-600 μm, the bottom diameter is 200-300 μm, and the spacing between adjacent tips is 200-1000 μm.

[0061] Each microneedle is composed of a base 3, a core layer 2, and a cortex 1. The cortex is the outermost part of the microneedle tip for contacting the user and piercing the skin during use, and the base is the side of the microneedle away from the tip. A cavity for accommodating the core layer is formed between the cortex and the base. The cortex is formed from a cortex solution including silk fibroin and a structure regulator, the core layer is formed from a core layer solution including a water-soluble polymer compound and a glucagon-like peptide-1 receptor agonist, and the base is formed from a base solution including silk fibroin and a structure regulator.

[0062] The structure regulator is used to make the silk fibroin in the cortex form a stable SilkⅠcrystalline structure to have the advantages of high swelling and low dissolution loss. The glucagon-like peptide-1 receptor agonist in the core layer is solid when not in use to avoid binding with silk fibroin. After the microneedle pierces the skin, body fluid enters the core layer through the cortex, the water-soluble polymer compound dissolves to form a high-viscosity hydrogel, the glucagon-like peptide-1 receptor agonist returns to the negatively charged free state after contacting water, is repelled by the anionic polymer, and then is released through the swelling network of the silk fibroin in the cortex and enters the human body.

[0063] The mass of the glucagon-like peptide-1 receptor agonist in the core layer is 2%-10% of the mass of the water-soluble polymer. The mass of the structure regulator in the cortex and the base is 10-40% of the mass of the silk fibroin, and the mass ratio of the structure regulator in the base is greater than that in the cortex. Preferably, the mass of the structure regulator in the cortex is 10-35% of the mass of the silk fibroin, and the mass of the structure regulator in the base is 30-40% of the mass of the silk fibroin.

[0064] The glucagon-like peptide-1 receptor agonist is one or more selected from semaglutide, liraglutide, and tirzepatide. The structural regulator is one or more selected from proline, sorbitol, and xylitol, and the preferred structural regulator is proline. The water-soluble polymer compound is one or more selected from sodium hyaluronate, sodium carboxymethylcellulose, sodium alginate, and sodium carboxymethyl starch, and the preferred water-soluble polymer compound is sodium hyaluronate. The water-soluble polymer compound is used to form a liquid with a certain viscosity to uniformly and stably disperse and encapsulate the glucagon-like peptide-1 receptor agonist such as the liraglutide drug, and smoothly enter the cavity of the microneedle cortex during the preparation process.

[0065] Example 2 Preparation of Microneedle Raw Material - Silk Fibroin Solution

[0066] This example is a preparation method of silk fibroin solution, and the specific steps are as follows:

[0067] 1) Degumming treatment of silkworm cocoons

[0068] Weigh 80 g of silkworm cocoon shells, 1 g of anhydrous sodium carbonate, and 3 g of sodium bicarbonate. Add 4 L of deionized water to the degumming pot and heat to boiling, then add 1 g of anhydrous sodium carbonate, 3 g of sodium bicarbonate, and silkworm cocoon shells in sequence. After boiling gently for 30 min, take out the silkworm cocoons for cleaning. Repeat the above steps three times, and then place the degummed silk fibers in an oven to dry.

[0069] 2) Dissolution

[0070] Prepare a 9.3 M lithium bromide solution, measure 100 mL and heat it in a water bath to 65 °C. Weigh 15 g of degummed silk fibroin fibers and add them to the lithium bromide solution in batches. Stir to dissolve and continue to dissolve for 40 min.

[0071] 3) Dialysis purification

[0072] Dialyze the silk fibroin lithium bromide solution with a dialysis bag at 4 °C for three days to obtain an aqueous silk fibroin solution, and store it in a 4 °C refrigerator.

[0073] Example 3 Preparation Method

[0074] The preparation method of the silk fibroin core-shell microneedles with high drug loading of liraglutide in this example includes the following steps:

[0075] 1) Preparation of the cortex part:

[0076] Prepare the cortex solution: Weigh proline with a mass of 20% of the mass of silk fibroin, dissolve it in water, and mix it with the silk fibroin solution prepared in Example 2 to obtain the cortex solution. Ensure that the concentration of silk fibroin in the cortex solution is 18 mg / mL.

[0077] Coating and drying: Pour the prepared cortical solution evenly onto a polydimethylsiloxane mold. Repeat the vacuum pumping three times to fully expel the air in the mold. Then, place the mold in a constant temperature and humidity chamber and dry it for 12 h under convective air to completely dry and cure the cortical solution, obtaining the cortical part of the microneedles.

[0078] 2) Preparation of the core part:

[0079] Preparation of the core solution: Weigh liraglutide drug at 10% of the mass of hyaluronic acid in the core, dissolve it in water and mix it with the sodium hyaluronate solution to obtain the core solution. Ensure that the concentration of sodium hyaluronate in the core solution is 2 wt%.

[0080] Coating and drying: Pour the prepared core solution evenly into the dried microneedle cortex above, pump vacuum three times in a vacuum drying oven, scrape off the bubbles after taking it out, and continuously repeat the above steps three times. Place it in a constant temperature and humidity chamber and dry it for 8 h to obtain the core part of the microneedles.

[0081] 3) Preparation of the base part:

[0082] Dissolve the structural regulator in water and mix it with the silk fibroin solution to obtain the base solution. The concentration of silk fibroin in the base solution is 40 mg / mL, and it contains 35% proline by mass of silk fibroin.

[0083] Pour the base solution evenly on the side of the microneedle far from the tip, dry it at 40 °C for 8 h, and use it as the base part of the drug-loaded microneedles. After complete drying, demold to obtain the drug-loaded microneedles.

[0084] Preparation method of Example 4

[0085] The preparation method of the silk fibroin core-shell microneedles with low drug loading of liraglutide in this example includes the following steps:

[0086] 1) Preparation of the cortical part:

[0087] Preparation of the cortical solution: Weigh sorbitol at 25% of the mass of silk fibroin, dissolve it in water and mix it with the silk fibroin solution prepared in Example 2 to obtain the cortical solution. Ensure that the concentration of silk fibroin solute in the cortical solution is 15 mg / mL.

[0088] Coating and drying: Pour the prepared cortical solution evenly onto a polydimethylsiloxane mold. To ensure the uniformity and integrity of the microneedle structure, it is necessary to pump vacuum in a vacuum drying oven until the vacuum degree reaches -0.09 Mpa, repeat the vacuum pumping three times to fully expel the air in the mold. Then, place the mold in a constant temperature and humidity chamber and dry it for 6 h under convective air to completely dry and cure the cortical solution, obtaining the cortical part of the microneedles.

[0089] 2) Preparation of the core layer part:

[0090] Prepare the core layer solution: Weigh liraglutide drug at 2% of the mass of sodium hyaluronate in the core layer part, dissolve it in water and mix it with the sodium hyaluronate solution to obtain the core layer solution. Ensure that the concentration of sodium hyaluronate in the core layer solution is 1 wt%.

[0091] Coating and drying: Pour the prepared core layer solution evenly onto the above-mentioned dried microneedle base, evacuate the vacuum drying oven 3 times, take it out, scrape off the air bubbles, and repeat the above steps continuously 3 times. Then place it in a constant temperature and humidity chamber and dry for 4 h to obtain the core layer part of the microneedles.

[0092] 3) Preparation of the base part:

[0093] Dissolve the structural regulator in water and mix it with the silk fibroin solution to obtain the base solution. The concentration of silk fibroin in the base solution is 50 mg / mL and it contains 30% of the mass of silk fibroin of proline.

[0094] Pour the base solution evenly on the side of the microneedle far from the tip, and also place it in a constant temperature and humidity chamber and dry for 6 h, which is used as the base part of the drug-loaded microneedles. After ensuring complete drying, demoulding can obtain the drug-loaded microneedles.

[0095] Preparation method of Example 5

[0096] The preparation method of the silk fibroin core-shell microneedles with high drug loading of semaglutide in this example includes the following steps:

[0097] 1) Preparation of the cortex part:

[0098] Prepare the cortex solution: Weigh proline with a mass of 19% of the mass of silk fibroin, dissolve it in water and mix it with the silk fibroin solution prepared in Example 2 to obtain the cortex solution. Ensure that the concentration of silk fibroin solute in the cortex solution is 20 mg / mL.

[0099] Coating and drying: Pour the prepared cortex solution evenly onto the polydimethylsiloxane mold. To ensure the uniformity and integrity of the microneedle structure, it is necessary to evacuate the vacuum drying oven to a vacuum degree of -0.09 Mpa, repeat evacuating 3 times to fully discharge the air in the mold. Then, place the mold in a constant temperature and humidity chamber and dry for 8 h under convective air to completely dry and solidify the cortex solution to obtain the cortex part of the microneedles.

[0100] 2) Preparation of the core layer part:

[0101] Prepare the core layer solution: Weigh semaglutide drug at 6% of the mass of sodium alginate in the core layer part, dissolve it in water and mix it with sodium alginate to obtain the core layer solution. Ensure that the concentration of sodium alginate in the core layer solution is 1 wt%.

[0102] Coating and drying: The prepared core layer solution was evenly poured onto the dried microneedle base described above. It was evacuated 3 times in a vacuum drying oven, taken out, and the bubbles were scraped off, and the above steps were continuously repeated 3 times. Then it was placed in a constant temperature and humidity chamber and dried for 5 h to obtain the core layer part of the microneedles.

[0103] 3) Preparation of the base part:

[0104] The structural regulator was dissolved in water and mixed with the silk fibroin solution to obtain the base solution. The concentration of silk fibroin in the base solution was 80 mg / mL, and it contained 35% sorbitol by mass of silk fibroin.

[0105] The base solution was evenly poured on the side of the microneedle far from the tip, and it was also placed in a constant temperature and humidity chamber and dried for 7 h, which was used as the base part of the drug-loaded microneedles. After ensuring complete drying, the drug-loaded microneedles could be demolded.

[0106] Preparation method of Example 6

[0107] The preparation method of the low-drug-loading silk fibroin core-shell microneedles loaded with semaglutide in this example includes the following steps:

[0108] 1) Preparation of the cortex part:

[0109] Preparation of the cortex solution: Xylitol with a mass of 32% of the silk fibroin mass was weighed, dissolved in water and mixed with the silk fibroin solution prepared in Example 2 to obtain the cortex solution. Ensure that the concentration of silk fibroin solute in the cortex solution is 10 mg / mL.

[0110] Coating and drying: The prepared cortex solution was evenly poured onto the polydimethylsiloxane mold. To ensure the uniformity and integrity of the microneedle structure, it was evacuated in a vacuum drying oven to a vacuum degree of -0.09 Mpa, and the vacuum was repeated 3 times to fully discharge the air in the mold. Then, the mold was placed in a constant temperature and humidity chamber and dried for 7 h under convective air to completely dry and solidify the cortex solution to obtain the cortex part of the microneedles.

[0111] 2) Preparation of the core layer part:

[0112] Preparation of the core layer solution: Semaglutide peptide drug was weighed at 3% of the mass of sodium carboxymethylcellulose in the core layer part, dissolved in water and mixed with sodium carboxymethylcellulose to obtain the core layer solution. Ensure that the concentration of sodium carboxymethylcellulose in the core layer solution is 4 wt%.

[0113] Coating and drying: Pour the prepared core layer solution evenly onto the above-mentioned dried microneedle base, evacuate the vacuum drying oven 3 times, take it out, scrape off the air bubbles, and repeat the above steps continuously 3 times. Then place it in a constant temperature and humidity chamber for drying for 8 h to obtain the core layer part of the microneedles.

[0114] 3) Preparation of the base part:

[0115] Dissolve the structural regulator in water and mix it with the silk fibroin solution to obtain the base solution. The concentration of silk fibroin in the base solution is 100 mg / mL, and it contains xylitol accounting for 40% of the mass of silk fibroin.

[0116] Pour the base solution evenly on the side of the microneedle far from the tip, and also place it in a constant temperature and humidity chamber for drying for 10 h to use it as the base part of the drug-loaded microneedles. After ensuring complete drying, demoulding can obtain the drug-loaded microneedles.

[0117] Preparation method of Example 7

[0118] The preparation method of the high drug-loading silk fibroin core-shell microneedles loaded with teprotide in this example includes the following steps:

[0119] 1) Preparation of the cortex part:

[0120] Preparation of the cortex solution: Weigh proline accounting for 28% of the mass of silk fibroin, dissolve it in water and mix it with the silk fibroin solution prepared in Example 2 to obtain the cortex solution. Ensure that the concentration of silk fibroin solute in the cortex solution is 19 mg / mL.

[0121] Coating and drying: Pour the prepared cortex solution evenly onto the polydimethylsiloxane mold. To ensure the uniformity and integrity of the microneedle structure, it is necessary to evacuate the vacuum drying oven to a vacuum degree of -0.09 Mpa, repeat evacuating the vacuum 3 times to fully discharge the air in the mold. Then, place the mold in a constant temperature and humidity chamber and dry it under convective air for 9 h to completely dry and solidify the cortex solution to obtain the cortex part of the microneedles.

[0122] 2) Preparation of the core layer part:

[0123] Preparation of the core layer solution: Weigh teprotide drug accounting for 7% of the mass of sodium carboxymethyl starch in the core layer part, dissolve it in water and mix it with sodium carboxymethyl starch to obtain the core layer solution. Ensure that the concentration of sodium carboxymethyl starch in the core layer solution is 6 wt%.

[0124] Coating and drying: Pour the prepared core layer solution evenly onto the above-mentioned dried microneedle base, evacuate the vacuum drying oven 3 times, take it out, scrape off the air bubbles, and repeat the above steps continuously 3 times. Then place it in a constant temperature and humidity chamber for drying for 6 h to obtain the core layer part of the microneedles.

[0125] 3) Preparation of the base part:

[0126] Dissolve the structural regulator in water and mix it with the silk fibroin solution to obtain the base solution. The concentration of silk fibroin in the base solution is 60 mg / mL, and it contains sorbitol accounting for 35% of the mass of silk fibroin.

[0127] Pour the base solution evenly on the side of the microneedle far from the tip, and also place it in a constant temperature and humidity chamber for drying for 4 h, which is used as the base part of the drug-loaded microneedle. After ensuring complete drying, demolding can obtain the drug-loaded microneedle.

[0128] Preparation method of Example 8

[0129] The preparation method of the silk fibroin core-shell microneedle with low drug loading of telotristat ethyl in this example includes the following steps:

[0130] 1) Preparation of the cortex part:

[0131] Prepare the cortex solution: Weigh sorbitol accounting for 35% of the mass of silk fibroin, dissolve it in water and mix it with the silk fibroin solution prepared in Example 2 to obtain the cortex solution. Ensure that the concentration of silk fibroin solute in the cortex solution is 13 mg / mL.

[0132] Coating and drying: Pour the prepared cortex solution evenly on the polydimethylsiloxane mold. To ensure the uniformity and integrity of the microneedle structure, it is necessary to evacuate the vacuum drying oven to a vacuum degree of -0.09 Mpa and repeat evacuating the vacuum 3 times to fully discharge the air in the mold. Then, place the mold in a constant temperature and humidity chamber and dry it under convective air for 11 h to completely dry and solidify the cortex solution, obtaining the cortex part of the microneedle.

[0133] 2) Preparation of the core part:

[0134] Prepare the core solution: Weigh telotristat ethyl drug at 4% of sodium hyaluronate in the core, dissolve it in water and mix it with sodium hyaluronate to obtain the core solution. Ensure that the concentration of sodium hyaluronate in the core solution is 1.5 wt%.

[0135] Coating and drying: Pour the prepared core solution evenly on the dried microneedle base above, evacuate the vacuum 3 times in the vacuum drying oven, scrape off the air bubbles after taking it out, and continuously repeat the above steps 3 times. Then place it in a constant temperature and humidity chamber and dry it for 7 h to obtain the core part of the microneedle.

[0136] 3) Preparation of the base part:

[0137] Dissolve the structural regulator in water and mix it with the silk fibroin solution to obtain the base solution. The concentration of silk fibroin in the base solution is 90 mg / mL, and it contains sorbitol accounting for 40% of the mass of silk fibroin.

[0138] Pour the base solution evenly on the side of the microneedle away from the tip, and also place it in a constant temperature and humidity chamber to dry for 5 h, which is used as the base part of the drug-loaded microneedle. After ensuring complete drying, the drug-loaded microneedle can be demolded.

[0139] Comparative Example 1

[0140] The preparation method of the silk fibroin skeleton type microneedle loaded with liraglutide in this comparative example includes the following steps:

[0141] 1) Prepare the mixed solution:

[0142] Weigh an appropriate amount of proline and liraglutide and dissolve them with deionized water. Mix the proline solution, silk fibroin solution and liraglutide solution, and the mass ratio of the three in the mixed solution is 0.5:10:1. The concentration of silk fibroin in the mixed solution is 39 mg / mL.

[0143] 2) Prepare the microneedles:

[0144] Drop the above mixed solution evenly on the polydimethylsiloxane mold. Place the mold in a vacuum drying oven and evacuate it 3 times to fully discharge the air in the mold and ensure that there are no bubbles or defects in the microneedles.

[0145] 3) Demold:

[0146] Place the microneedle mold after vacuum treatment in a constant temperature and humidity box (temperature 25 °C, relative humidity 60%). Dry it in convective air for 24 h to gradually evaporate the water in the mixed solution, and demold to obtain the silk fibroin skeleton type microneedles loaded with liraglutide.

[0147] Comparative Example 2

[0148] This comparative example uses SD rats intraperitoneally injected with liraglutide drug solution, and the operation steps are as follows:

[0149] 1) Pretreatment before the experiment

[0150] Dissolve the liraglutide drug in the sterilized PBS solution to prepare a 1 mg / ml drug solution, and inject 1 ml of the drug solution from the abdominal cavity of the rat using a disposable sterile syringe.

[0151] 2) Sample collection

[0152] Blood is collected at 8 time points of 1, 2, 4, 6, 8, 10, 12, and 24 h after drug administration. Blood is collected into a K2EDTA anticoagulation tube by tail clipping, inverted and mixed, centrifuged at 3000 r / min for 15 min at 4 °C, the supernatant is taken and stored at -80 °C for later measurement, and the sample needs to be slowly thawed in a 4 °C refrigerator before detection.

[0153] 3) Sample pretreatment

[0154] Before injection analysis, all samples need to be pretreated. Since there are many proteins in rat plasma, to eliminate their influence, absolute ethanol containing 2% ammonia water is added for protein precipitation. Take 60 μL of plasma working solution and add 96 μL of protein precipitant. After vortexing, centrifuge at 4 °C and 13,000 rpm for 10 min. After centrifugation, take the supernatant and dilute it with 20% ammonia water according to the ratio of 1 / 1 (v / v), and then detect the blood drug concentration of liraglutide by HPLC.

[0155] Testing and result discussion

[0156] I. In vitro transdermal drug release detection was carried out on the silk fibroin microneedles prepared in Examples 3 - 8 and Comparative Example 1:

[0157] (1) Assembly of in vitro drug release device

[0158] Soak the frog skin in physiological saline for thawing, cut out frog skins with the same thickness and integrity, and dry them with absorbent paper. Pierce the microneedles prepared in Examples 3 - 8 and Comparative Example 1 into the frog skin with the tip facing down, and clamp the donor chamber and the receiving pool with a steel clip to ensure that the frog skin contacts the solution in the receiving pool. Use pure water as the simulated body fluid, and the volume of the receiving pool is 5 mL. The water bath temperature of the transdermal release cell is 35 °C, and the rotor speed is 300 r / min.

[0159] (2) Experimental sampling:

[0160] In the drug release device of the above steps, sampling was carried out at 0, 0.5, 1, 2, 4, 6, and 10 h respectively. The half-life of subcutaneous injection of liraglutide is 13 h. To simulate the characteristics of the biological half-life, 1 mL was taken each time and 1 mL of pure water was added. The taken solution was filtered through a 0.45 μm filter, and the concentration of liraglutide was detected using a liquid chromatograph.

[0161] (3) Chromatographic conditions

[0162] A Potensil C18 column (4.6×250 mm, 5 μm) was used, the column temperature was 40 °C, the flow rate was 0.6 mL / min, and the injection volume was set to 40 μL. Mobile phase A was an aqueous solution containing 0.1% trifluoroacetic acid, and mobile phase B was an acetonitrile solution containing 0.1% trifluoroacetic acid. Detection wavelength: 214 nm. The gradient elution program was as follows: 0 - 3 min, 20% B; 3 - 23 min, 60% B; 23 - 26 min, 100% B; 26 - 37 min, 20% B.

[0163] II. The pharmacokinetics of the core - shell silk fibroin microneedles loaded with liraglutide prepared in Example 3 in rats was studied, and the specific operation steps are as follows.

[0164] (1) Application of microneedle patch

[0165] Use an electric clipper and depilatory cream to remove the hair on the back of the rats, and clean it with flowing clear water. Use a medical dressing to apply the microneedle patch on the back of the SD rats, and press the microneedle patch with a force of 3 N to ensure that the microneedles penetrate the skin.

[0166] (2) Pharmacokinetic detection

[0167] The single-dose of the microneedle group and the injection group was the same. The above experimental groups collected tail vein blood at 1, 2, 4, 6, 8, 10, 12, and 24 h after administration (N = 3). The blood collection volume each time was 60 μL. Add 96 μL of protein precipitant (anhydrous ethanol containing 2% ammonia water), vortex for 1 min, and after centrifugation, take the supernatant and dilute it with 20% ammonia water according to a ratio of 1 / 1 (v / v), and then perform liquid chromatography detection.

[0168] Test results

[0169] I. Figure 2 Shows the in vitro transdermal release curves of the microneedle patches prepared in Examples 3-8 and Comparative Example 1.

[0170] Among them, Examples 3, 5, and 7 are high drug-loading groups, and Examples 4, 6, and 8 are low drug-loading groups. The drug release rate of the microneedle of Comparative Example 1 with a skeleton type is extremely slow, and the end point of drug release equilibrium is reached at 6 hours. This is because the binding force between the glucagon-like peptide-1 receptor agonist and the protein molecule is too strong. The release rate of the core-shell microneedle patch shows different trends and numerical changes according to different drug loadings. Among them, the release rate curve of the low drug-loading microneedle patch is relatively flat, with small differences, and all reach the release peak at about 2 h. The release rate curves of the high drug-loading microneedle patches are different. The release rate curve of the microneedle prepared in Example 3 is the flattest, and the release rate curves of the microneedles prepared in Examples 5 and 7 are relatively sharp. The microneedle prepared in Example 3 reaches the release rate peak of 30.4 μg / h·cm 2 and the drug release rate per unit area maintains at 25-30 μg / h·cm within 2-12 h 2 . In the in vitro release of the core-shell silk fibroin microneedles, liraglutide has the best release effect.

[0171] II. Figure 3It shows the dynamic change process of the blood drug concentration in animals of the microneedles prepared in Example 3, the injection group of Comparative Example 2, and the blank group. Intraperitoneal injection, as a direct drug administration method, enables the drug to quickly enter the peritoneal cavity and then enter the blood circulation. The blood drug concentration can rapidly reach the highest value in the early stage (2h), which is 31.83±1.61 μg / ml, and then the drug concentration rapidly decays. The core-shell microneedles prepared in Example 3 present different pharmacokinetic characteristics. The drug is slowly released into the skin through the microneedles and then enters the blood circulation via capillaries. Therefore, the increase in blood drug concentration is relatively slow. The blood drug concentration-time curve is relatively flat, and the peak arrival time is 10h. The blood drug concentration remains in the range of 10-20 μg / mL within 4-12h. For the treatment of diabetes, a stable and continuous drug concentration can achieve long-term balanced regulation of blood glucose.

[0172] The core-shell silk fibroin microneedle patch of the present invention is a transdermal drug delivery technology, which can avoid the pain caused by injection and the problem of excessive change in blood drug concentration, and improve the compliance of patients. The structure of the core-shell layer enables the drug to slowly pass through the cortex and be released via the swelling network of the cortex. A 24-hour drug release is achieved, which can play a long-term therapeutic effect.

[0173] The molecular structure of GLP-1RA is special and contains a long carbon chain. The advantage is that it can extend the half-life of GLP-1RA in vivo, but the disadvantage is that its interaction force with silk fibroin is too high. When silk fibroin is in direct contact with the glucagon-like peptide-1 receptor agonist, a molecular conjugate is formed at the contact surface, resulting in difficulty in releasing from the silk fibroin microneedles. In this application, through the structure of the core-shell layer, the direct contact between silk fibroin and GLP-1RA molecules is isolated, and GLP-1RA is placed in the core layer. Then, an anionic polymer is used to form a high-viscosity sol with GLP-1RA after absorbing body fluid, wrapping the glucagon-like peptide-1 receptor agonist to prevent it from binding to silk fibroin molecules, and then slowly releasing it from the cortex of silk fibroin. In this way, the core layer plays the role of a sustained-release gel, and the silk fibroin in the cortex plays the role of a sustained-release diaphragm. The two work together to enable GLP-1RA to obtain a sustained-release effect of up to 24h. At the same time, the high strength of silk fibroin is also utilized to construct a microneedle that can pierce the skin.

[0174] The glucagon-like peptide-1 receptor agonist fibroin core-shell microneedle patch of the present invention and its preparation method aim to achieve the safe, convenient and effective loading and drug delivery of glucagon-like peptide-1 receptor agonist analogs, and achieve the effect of sustained release and long-term efficacy. The microneedles of the microneedle patch are composed of a cortex, a core layer and a base. The cortex is composed of fibroin and a structural regulator, the core layer is composed of a water-soluble polymer compound and liraglutide, and the base is composed of water-insoluble fibroin. The fibroin core-shell microneedle patch provided by the present invention effectively reduces the influence of fibroin molecules on drug molecules by spatially separating the glucagon-like peptide-1 receptor agonist from fibroin. This design improves the cumulative drug release rate of the high drug-loading microneedles. At the same time, by using the action of a structural regulator on fibroin, microneedles with swelling characteristics are formed, thus realizing the sustained release effect of the drug. Within the time range of 3-12 h, the microneedles can maintain a stable drug release rate of 25-30 μg / h·cm 2 In addition, through animal pharmacokinetic studies, it is shown that the core-shell microneedle administration method can continuously release the drug, thereby maintaining a stable blood drug concentration in rats. Within the time range of 4-12 h after administration, the blood drug concentration can be maintained within the range of 10-20 μg / mL, showing the significant advantages of the core-shell microneedle administration method in controlling drug release and maintaining therapeutic effects.

[0175] The above embodiments are only used to illustrate the technical concept and characteristics of the present invention, and their purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it accordingly, and it cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit and essence of the present invention should be covered within the protection scope of the present invention.

[0176] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

Claims

1. A silk fibroin microneedle patch carrying a glucagon-like peptide-1 receptor agonist, characterized in that: It comprises a plurality of microneedles, each of which comprises a cortex, a core layer and a base in sequence, a cavity for accommodating the core layer is formed between the cortex and the base, the cortex comprises silk fibroin and a structural regulator, the core layer comprises a water-soluble polymer compound and a glucagon-like peptide-1 receptor agonist, and the base comprises silk fibroin and a structural regulator; the cortex is used to contact a user during use.

2. The silk fibroin microneedle patch according to claim 1, characterized in that: The mass of the glucagon-like peptide-1 receptor agonist in the core layer is 2%-10% of the mass of the water-soluble high molecular compound.

3. The silk fibroin microneedle patch according to claim 1 or 2, characterized in that: The glucagon-like peptide-1 receptor agonist is one or more selected from semaglutide, liraglutide, and telpotide.

4. The silk fibroin microneedle patch according to claim 1, characterized in that: The mass of the structure regulator in the cortex and the base is 10-40% of the mass of the silk fibroin.

5. The silk fibroin microneedle patch according to claim 4, characterized in that: The mass proportion of the structural regulator in the base is greater than the mass proportion of the structural regulator in the cortex.

6. The silk fibroin microneedle patch according to claim 1 or 4, characterized in that: The structure regulator is one or more selected from proline, sorbitol and xylitol.

7. The silk fibroin microneedle patch according to claim 1, characterized in that: The water-soluble polymer compound is one or more selected from sodium hyaluronate, sodium carboxymethyl cellulose, sodium alginate, and sodium carboxymethyl starch.

8. The silk fibroin microneedle patch according to claim 1, characterized in that: The height of the microneedles in the silk fibroin microneedle patch is 300-1000 μm, the base diameter is 200-500 μm, and the spacing between adjacent needle tips is 200-1000 μm.

9. A method for preparing a silk fibroin microneedle patch loaded with a glucagon-like peptide-1 receptor agonist according to any one of claims 1 to 8, characterized in that: The steps include: Dissolving the structure regulator in water and mixing it with the silk fibroin solution to obtain a cortex solution; The cortex solution is poured into a mold, defoamed, and dried under constant temperature and humidity and air convection to obtain the cortex of the microneedle; The glucagon-like peptide-1 receptor agonist is dissolved in water and then mixed with a water-soluble polymer compound to obtain a core layer solution; pouring the core layer solution into the cortex of the microneedle, defoaming, and drying under constant temperature and humidity to obtain the core layer of the microneedle; Dissolving the structure regulator in water and mixing it with the silk fibroin solution to obtain a base solution; The base solution is poured onto the side of the microneedle away from the needle tip, and after drying, the base is obtained, and demoulding is performed to obtain the silk fibroin microneedle patch.

10. The preparation method according to claim 9, characterized in that: The concentration of the water-soluble polymer compound in the core layer solution is 1-10 wt %.

11. The preparation method according to claim 9, characterized in that: The concentration of silk fibroin in the cortex solution is lower than the concentration of silk fibroin in the base solution.

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