Preparation for treating diabetes, microneedle and preparation process thereof

Abstract

In order to overcome the problems that existing microneedles cannot achieve continuous and controllable regulation of blood sugar and are easy to break, causing inflammation and infection in the skin, the present invention provides a preparation for treating diabetes, including nanocellulose-based hydrogel, dipeptidyl peptidase-4 inhibitor, and glucokinase. The present invention also provides a microneedle loaded with the preparation. At the same time, the present invention also discloses a method for preparing the above-mentioned microneedles, comprising the following steps: first introducing the solution forming the inner layer into a molding mold, scraping the solution into the molding cavity of the molding mold by a scraper, demolding after vacuum drying, obtaining inner layer microneedles, re-injecting the outer layer solution into the molding cavity of the molding mold, and then inserting the inner layer microneedles into the molding cavity containing the outer layer solution, and obtaining the microneedles after vacuum drying and demolding.

Description

Technical Field

[0001] The present invention belongs to the technical field of metabolic disease drugs, and specifically relates to a preparation for treating diabetes, a microneedle and a preparation process thereof. Background Art

[0002] Diabetes is a metabolic disease characterized by chronic hyperglycemia caused by defective or impaired insulin secretion. It has a serious impact on the patient's physical health, and timely control of blood sugar levels is necessary to prevent a series of functional disorders and damage caused by diabetes. At present, common sulfonylurea drugs in clinical practice include gliquidone, glipizide, glibenclamide, gliclazide, etc. The main mechanism of this type of drug in treating diabetes is to bind to specific receptors on the outside of the pancreatic β cell membrane to inhibit the closure of ATP-sensitive potassium ion channels on the cell membrane, reduce potassium ion outflow, increase intracellular potassium ion concentration, and initiate pancreatic β cells to release insulin to further achieve the effect of lowering blood sugar. However, if the drug dosage exceeds the actual required range, it may cause hypoglycemia, which may seriously endanger the patient's life and health.

[0003] In the prior art, microneedles are used to deliver insulin and other diabetes treatment drugs to the human body, but most of them are hollow microneedles or solid microneedles, mainly to control the amount of delivered drugs. However, in actual use, both hollow microneedles and solid microneedles have many problems. First, although the delivery amount of microneedles can be controlled, the glucose content in the patient's body cannot be accurately determined, so the blood sugar level cannot be accurately controlled; secondly, both hollow microneedles and solid microneedles are made of hard materials such as metal, which can easily cause the needle to break in the skin, causing skin inflammation and infection. Summary of the invention

[0004] In view of the problems that existing microneedles cannot achieve continuous and controllable regulation of blood sugar and are easy to break, causing inflammation and infection in the skin, the present invention provides a drug for treating diabetes, a microneedle and a preparation method thereof.

[0005] The technical solution adopted by the present invention to solve the above technical problems is as follows:

[0006] The invention provides a medicine for treating diabetes, comprising a nanocellulose-based hydrogel, a dipeptidyl peptidase-4 inhibitor and glucokinase.

[0007] Furthermore, the mass ratio of the nanocellulose-based hydrogel, the dipeptidyl peptidase-4 inhibitor, and the glucokinase is (3-8):(5-10):(1-2).

[0008] Furthermore, the nanocellulose-based hydrogel has a vesicle structure and encapsulates the dipeptidyl peptidase-4 inhibitor therein.

[0009] Furthermore, the dipeptidyl peptidase-4 inhibitor includes one or more of saxagliptin, vildagliptin, alogliptin and linagliptin.

[0010] Furthermore, the preparation method of the nanocellulose-based hydrogel is: using a delignification method to obtain a wood cellulose skeleton in wood as a base material, softening it through alkali treatment, and then compounding it with polyacrylamide gel to obtain the nanocellulose-based hydrogel.

[0011] The present invention also provides a microneedle for treating diabetes, wherein the microneedle carries the drug for treating diabetes.

[0012] Furthermore, the microneedle is a layered microneedle, including an outer layer and an inner layer, the solution forming the outer layer includes glucose kinase, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, sucrose, sodium chloride, and tris(hydroxymethyl)aminomethane; the solution forming the inner layer includes nanocellulose-based hydrogel, dipeptidyl peptidase-4 inhibitor, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, sucrose, sodium chloride, and tris(hydroxymethyl)aminomethane.

[0013] Furthermore, the mass ratio of the outer layer to the inner layer of the microneedle is (1-2):(5-8).

[0014] The present invention also provides a process for preparing the microneedles: firstly, the solution for forming the inner layer is introduced into a molding mold, the solution is scraped into the molding cavity of the molding mold by a scraper, and the mold is demolded after vacuum drying to obtain inner-layer microneedles, and the outer-layer solution is re-injected into the molding cavity of the molding mold, and then the inner-layer microneedles are inserted into the molding cavity containing the outer-layer solution, and the microneedles are obtained after vacuum drying and demolding.

[0015] According to a preparation for treating diabetes provided by the present invention, the main pharmacological substances are dipeptidyl peptidase-4 inhibitors and glucokinase, and the dipeptidyl peptidase-4 inhibitor can prevent dipeptidyl peptidase-4 from degrading GLP-1, thereby inhibiting its original effect and achieving the effect of increasing insulin secretion. Glucokinase can increase β-cell ATP to improve glucose-induced insulin synthesis and secretion, and glucokinase can also quickly metabolize glucose, inhibit liver glycogen storage, and then inhibit α-cells from secreting glucagon, but it cannot quickly react and stop in hypoglycemia, and the risk of hypoglycemia is relatively large, and combined use with dipeptidyl peptidase-4 inhibitors can effectively reduce the adverse reactions of hypoglycemia and improve the therapeutic safety of the drug. At the same time, the present invention also uses nanocellulose-based hydrogels to make vesicle structures, and dipeptidyl peptidase-4 inhibitors are wrapped inside. The nanocellulose-based hydrogel has good biocompatibility, can be biodegraded, non-toxic and harmless, and due to its unique nano-entangled network structure, it has good mechanical properties and certain hydrophobicity, and will not dissolve quickly in water. Glucokinase, as one of the hexokinase isozymes, can catalyze glucose into glucose-6-phosphate, and glucose-6-phosphate has excellent hydrophilicity. It can give the nanocellulose-based hydrogel a hydrophilic surface through the phosphate group, so that the nanocellulose-based hydrogel vesicles dissolve and release the dipeptidyl peptidase-4 inhibitor encapsulated therein. That is to say, the preparation of the present invention can control the release rate of the dipeptidyl peptidase-4 inhibitor according to the actual content of glucose in the body, thereby controlling the blood sugar level in the body within a stable range, that is, it can control excessive blood sugar content and avoid the occurrence of hypoglycemia.

[0016] According to the present invention, a microneedle is provided in the form of a layered needle, and the outer layer contains glucose kinase, which can diffuse in the body first after the microneedle is inserted into the body, catalyzing the conversion of glucose in the body into 6-phosphate glucose, and the inner layer of the microneedle begins to dissolve after the outer layer dissolves to release the nanocellulose-based hydrogel vesicles wrapped with dipeptidyl peptidase-4 inhibitor, which is endowed with hydrophilic dissolution by the 6-phosphate glucose produced in the body, thereby achieving the effect of lowering blood sugar. At the same time, the microneedle provided by the present invention is a soluble microneedle, which will dissolve quickly after being inserted into the skin, and there is no need to worry about the situation of needle breakage and infection caused by repeated use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of the structure of the layered microneedle provided by the present invention;

[0018] Figure 2 It is a schematic diagram of the vesicle structure provided by the present invention.

[0019] The reference numerals in the drawings of the specification are as follows:

[0020] 1. Microneedle outer layer; 2. Vesicles; 3. Microneedle inner layer; 4. Microneedle base; 5. Dipeptidyl peptidase-4 inhibitor; 6. Nanocellulose-based hydrogel. DETAILED DESCRIPTION

[0021] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] The present invention discloses a preparation for treating diabetes. In addition to being used to treat diabetes, the preparation can also treat complications caused by diabetes, including but not limited to diabetic neuropathy, diabetic retinopathy, diabetic nephropathy, glaucoma and diabetic ketoacidosis, or glucose metabolism disorders leading to hyperglycemia. In some embodiments, the preparation of the present invention can also be used to treat some endocrine metabolic diseases other than diabetes, such as obesity, osteoporosis, hyperuricemia, etc.

[0023] In some embodiments, the preparation includes a dipeptidyl peptidase-4 inhibitor, glucokinase, and a nanocellulose-based hydrogel. Among them, the main function of the dipeptidyl peptidase-4 inhibitor is to prevent the protein in the body from being decomposed by dipeptidyl peptidase-4. One of the proteins decomposed by dipeptidyl peptidase-4 is called GLP-1, which is a hormone secreted by intestinal cells. GLP-1 can lower blood sugar by stimulating insulin, inhibiting glucagon, inhibiting gastric emptying, and regenerating pancreatic islet cells, resulting in dipeptidyl peptidase-4 not decomposing GLP-1, thereby achieving the effect of lowering blood sugar. The dipeptidyl peptidase-4 inhibitor can be one or more of Sitagliptin, Vildagliptin, Saxagliptin, Alogliptin, and Linagliptin.

[0024] Glucokinase itself is a hypoglycemic substance, and its mechanism of action is as follows: when the pancreatic β cells sense that the blood glucose concentration is higher than 5mmol / L, glucokinase is activated and insulin secretion is initiated; the gradually increasing insulin acts on the liver cells and promotes the gene expression of hepatocyte glucokinase. When the blood glucose concentration rises to 8mmol / L, the liver glucokinase is activated and liver glycogen synthesis is initiated. The gene expression of liver glucokinase depends on insulin. When the blood glucose concentration drops below 4mmol / L, the activity of glucokinase decreases rapidly, activating the glucagon release mechanism of the pancreatic α cells. Glucagon acts on the receptors of the liver cells, activating the liver glycogenolysis and gluconeogenesis mechanism, transporting glucose to the body, and maintaining blood glucose homeostasis. Through the action of glucokinase, the body's most important glucose sensing cells and glucose disposal cells coordinate with each other to maintain blood glucose homeostasis. At the same time, glucose kinase is also one of the hexokinase isozymes, which plays a catalytic role in the phosphorylation process of glucose into 6-phosphate glucose. The enzyme activity of glucose kinase can also change with the concentration of glucose in the environment. When the glucose concentration is low, the enzyme activity increases slowly. When the glucose concentration rises to a certain level, the enzyme activity increases significantly and eventually increases to the maximum activity.

[0025] Nanocellulose-based hydrogel has a unique nano-entanglement network structure, excellent mechanical properties, high specific surface area, biodegradability and biocompatibility, and the spatial network structure near the π bond of the cellulose molecule gives it good hydrophobicity. The preparation method can be: using the delignification method to obtain the wood cellulose skeleton in the wood as the base material, softening it through alkali treatment, and then compounding it with polyacrylamide gel to obtain the nanocellulose-based hydrogel. In addition to the above preparation methods, nanocellulose-based hydrogels can also be prepared by the following process: take a certain mass of cotton linter cellulose (cut into pieces and vacuum dried at 80°C for 24 hours) and add it to a NaOH / urea / H2O (mass ratio of 7:12:8:1) solution for dispersion. After uniform dispersion, freeze it at -18°C for 12 hours, take it out and rapidly and vigorously stir it at room temperature for 10 minutes, centrifuge and degas at 5-10°C and 8000r / min for 5 minutes to obtain a transparent cellulose solution, pour the mixed solution into a mold, use 1% (mass fraction) HCL as a coagulation bath, neutralize NaOH, and then wash with deionized water to remove impurities. Replace the deionized water every 2 hours until the replacement fluid is neutral, and obtain a nanocellulose-based hydrogel at room temperature.

[0026] In some embodiments, Figure 2As shown, a nanocellulose-based hydrogel is used as a vesicle 2, and a dipeptidyl peptidase-4 inhibitor 5 is encapsulated therein. The term "vesicle" may refer to an artificially produced particle (in some embodiments, a nanoparticle) comprising a fluid surrounded by concentric layers or molecular or polymer layers (e.g., an amphiphilic polymer). The preparation process of the nanocellulose-based hydrogel vesicle is as follows: a 25 g / L dipeptidyl peptidase-4 inhibitor is taken in a round-bottom flask, slowly dried with a nitrogen stream for 4-6 hours, HEPES buffer is added, and magnetic stirring is performed for 30 minutes to obtain a dipeptidyl peptidase-4 inhibitor suspension, and the suspension is added to an extruder equipped with a nanocellulose-based hydrogel, and the suspension passes through the nanocellulose-based hydrogel membrane pores to produce a nanocellulose-based hydrogel vesicle encapsulated with a dipeptidyl peptidase-4 inhibitor.

[0027] In some embodiments, other pharmacological substances may also be encapsulated in the nanocellulose-based hydrogel vesicles, including but not limited to one or more of the following substances: insulin, metformin, sodium-glucose symporter-2 inhibitor, glucagon-like peptide-1 receptor agonist, α-glucosidase inhibitor, rosiglitazone, pioglitazone, etc.

[0028] The present invention also discloses a microneedle for treating diabetes, the length of the microneedle can be between about 50 μm and 2 mm, in most cases, between about 200 μm and 1200 μm, and ideally between about 500 μm and 1000 μm.

[0029] In some embodiments, Figure 1 As shown, the microneedle is a layered microneedle, including an outer layer 1 and an inner layer 3. The outer layer 1 is the surface layer that first contacts the internal environment after the microneedle is inserted into the body, and the inner layer 3 is covered in the outer layer 1 and contacts the internal environment only after the outer layer 1 dissolves or falls off.

[0030] In some embodiments, the solution forming the outer layer includes the glucokinase, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, sucrose, sodium chloride, tris(hydroxymethyl)aminomethane. At the same time, the solution may also include polyoxyethylene polyoxypropylene glycol, polyethylene glycol, polyvinyl alcohol, protein (e.g., gelatin, etc.), hyaluronic acid, sodium hyaluronate, amylopectin, dextran, dextrin, sodium chondroitin sulfate, cellulose derivatives (e.g., water-soluble cellulose derivatives partially modified by cellulose such as carboxymethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, etc.), hydroxyethyl starch, gum arabic, maltose, lactose, fructose, phosphoric acid, tris(hydroxymethyl)aminomethane, acetic acid, or one or more thereof.

[0031] When the microneedle is inserted into the human body, the outer layer begins to dissolve when it comes into contact with body fluids. The glucose kinase in it then diffuses into the internal environment and is activated by the glucose in the body. It begins to play its own glucose regulation function and can also act as a catalyst to convert glucose into 6-phosphate glucose.

[0032] In certain embodiments, the solution forming the inner layer includes nanocellulose-based hydrogel, dipeptidyl peptidase-4 inhibitor, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, sucrose, sodium chloride, tris(hydroxymethyl)aminomethane. Meanwhile, polyoxyethylene polyoxypropylene glycol, polyethylene glycol, polyvinyl alcohol, protein (e.g., gelatin, etc.) can also be included in the solution. Hyaluronic acid, sodium hyaluronate, amylopectin, dextran, dextrin, sodium chondroitin sulfate, cellulose derivatives (e.g., water-soluble cellulose derivatives that are locally modified by carboxymethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methylcellulose, etc.), hydroxyethyl starch, gum arabic, maltose, lactose, fructose, phosphoric acid, tris(hydroxymethyl)aminomethane, one or more of acetic acid.

[0033] When the outer layer of the microneedle dissolves, the inner layer begins to contact the body environment, and the nanocellulose-based hydrogel vesicles encapsulated with the dipeptidyl peptidase-4 inhibitor are released into the body environment. When the glucose content in the body environment is low, the amount of 6-phosphate glucose converted is relatively small. Since the nanocellulose-based hydrogel is hydrophobic and not easily dissolved in the body, the dipeptidyl peptidase-4 inhibitor encapsulated inside will not be released, that is, the blood sugar will not continue to be lowered to cause hypoglycemia. When the glucose content in the body is high, the amount of 6-phosphate glucose converted is relatively large. The phosphate groups on the 6-phosphate glucose can give the surface of the nanocellulose-based hydrogel vesicles hydrophilicity, so that the nanocellulose-based hydrogel vesicles quickly dissolve and release the dipeptidyl peptidase-4 inhibitor encapsulated inside, thereby quickly reducing the glucose content in the body environment and preventing high blood sugar.

[0034] The present invention also discloses a preparation process of microneedles, which process includes the following steps: firstly, the solution for forming the inner layer is introduced into the forming mold, and the solution is scraped into the forming cavity of the forming mold by a scraper, and since the forming cavity is made of a gas-permeable and liquid-impermeable material, the forming cavity is vacuum-sucked so that the solution fills the entire forming cavity. After vacuum drying, the mold is demoulded to obtain the inner layer microneedles, and the outer layer solution is re-injected into the forming cavity of the forming mold, and then the inner layer microneedles are inserted into the forming cavity containing the outer layer solution, and the microneedles are obtained after vacuum drying and demoulding.

[0035] The present invention is further described below by way of examples.

[0036] Example 1

[0037] A process for preparing microneedles for treating diabetes.

[0038] 1. Weigh 3.25 g of glucose kinase, 5.21 g of polyvinyl alcohol 03CP, 4.35 g of polyvinyl alcohol 30CP, 6.84 g of polyvinyl pyrrolidone K17, 9.62 g of hydroxyethyl cellulose, 2.56 g of sucrose, 3.92 g of sodium chloride, and 4.43 g of tris(hydroxymethyl)aminomethane, add 400 ml of purified water, and mix well to obtain a microneedle outer layer solution.

[0039] 2. Weigh 18.47 g of nanocellulose-based hydrogel, 8.43 g of dipeptidyl peptidase-4 inhibitor, 15.34 g of polyvinyl alcohol 03CP, 20.82 g of polyvinyl alcohol 30CP, 32.41 g of polyvinyl pyrrolidone K17, 39.73 g of hydroxyethyl cellulose, 12.58 g of sucrose, 18.32 g of sodium chloride, and 22.38 g of tris(hydroxymethyl)aminomethane, add 300 ml of purified water, and mix well to obtain a microneedle inner layer solution, in which the dipeptidyl peptidase-4 inhibitor is encapsulated by the nanocellulose-based hydrogel to form vesicles.

[0040] 3. Place the outer layer solution of the microneedle into the molding cavity of the molding mold, vacuum pump for 15 minutes, air-dry in a vacuum drying oven for 3 hours, demold, and obtain the inner layer microneedle. Re-inject the outer layer solution into the molding cavity of the molding mold, and then insert the inner layer microneedle into the molding cavity containing the outer layer solution. After vacuum drying and demolding, the microneedle is obtained.

[0041] Example 2

[0042] A process for preparing microneedles for treating diabetes.

[0043] 1. Weigh 4.38 g of glucose kinase, 5.21 g of polyvinyl alcohol 03CP, 4.35 g of polyvinyl alcohol 30CP, 6.84 g of polyvinyl pyrrolidone K17, 9.62 g of hydroxyethyl cellulose, 2.56 g of sucrose, 3.92 g of sodium chloride, and 4.43 g of tris(hydroxymethyl)aminomethane, add 400 ml of purified water, and mix well to obtain a microneedle outer layer solution.

[0044] 2. Weigh 27.32 g of nanocellulose-based hydrogel, 12.57 g of dipeptidyl peptidase-4 inhibitor, 15.34 g of polyvinyl alcohol 03CP, 20.82 g of polyvinyl alcohol 30CP, 32.41 g of polyvinyl pyrrolidone K17, 39.73 g of hydroxyethyl cellulose, 12.58 g of sucrose, 18.32 g of sodium chloride, and 22.38 g of tris(hydroxymethyl)aminomethane, add 300 ml of purified water, and mix well to obtain a microneedle inner layer solution, in which the dipeptidyl peptidase-4 inhibitor is encapsulated by the nanocellulose-based hydrogel to form vesicles.

[0045] 3. Place the outer layer solution of the microneedle into the molding cavity of the molding mold, vacuum pump for 16 minutes, air-dry in a vacuum drying oven for 3.5 hours, demold, and obtain the inner layer microneedle. Re-inject the outer layer solution into the molding cavity of the molding mold, and then insert the inner layer microneedle into the molding cavity containing the outer layer solution. After vacuum drying and demolding, the microneedle is obtained.

[0046] Example 3

[0047] A process for preparing microneedles for treating diabetes.

[0048] 1. Weigh 5.31 g of glucose kinase, 5.21 g of polyvinyl alcohol 03CP, 4.35 g of polyvinyl alcohol 30CP, 6.84 g of polyvinyl pyrrolidone K17, 9.62 g of hydroxyethyl cellulose, 2.56 g of sucrose, 3.92 g of sodium chloride, and 4.43 g of tris(hydroxymethyl)aminomethane, add 400 ml of purified water, and mix well to obtain a microneedle outer layer solution.

[0049] 2. Weigh 36.42 g of nanocellulose-based hydrogel, 11.72 g of dipeptidyl peptidase-4 inhibitor, 15.34 g of polyvinyl alcohol 03CP, 20.82 g of polyvinyl alcohol 30CP, 32.41 g of polyvinyl pyrrolidone K17, 39.73 g of hydroxyethyl cellulose, 12.58 g of sucrose, 18.32 g of sodium chloride, and 22.38 g of tris(hydroxymethyl)aminomethane, add 300 ml of purified water, and mix well to obtain a microneedle inner layer solution, in which the dipeptidyl peptidase-4 inhibitor is encapsulated by the nanocellulose-based hydrogel to form vesicles.

[0050] 3. Place the outer layer solution of the microneedle into the molding cavity of the molding mold, vacuum pump for 17 minutes, air-dry in a vacuum drying oven for 3.5 hours, demold, and obtain the inner layer microneedle. Re-inject the outer layer solution into the molding cavity of the molding mold, and then insert the inner layer microneedle into the molding cavity containing the outer layer solution. After vacuum drying and demolding, the microneedle is obtained.

[0051] Example 4

[0052] A process for preparing microneedles for treating diabetes.

[0053] 1. Weigh 6.42 g of glucose kinase, 5.21 g of polyvinyl alcohol 03CP, 4.35 g of polyvinyl alcohol 30CP, 6.84 g of polyvinyl pyrrolidone K17, 9.62 g of hydroxyethyl cellulose, 2.56 g of sucrose, 3.92 g of sodium chloride, and 4.43 g of tris(hydroxymethyl)aminomethane, add 400 ml of purified water, and mix well to obtain a microneedle outer layer solution.

[0054] 2. Weigh 43.28 g of nanocellulose-based hydrogel, 14.25 g of dipeptidyl peptidase-4 inhibitor, 15.34 g of polyvinyl alcohol 03CP, 20.82 g of polyvinyl alcohol 30CP, 32.41 g of polyvinyl pyrrolidone K17, 39.73 g of hydroxyethyl cellulose, 12.58 g of sucrose, 18.32 g of sodium chloride, and 22.38 g of tris(hydroxymethyl)aminomethane, add 300 ml of purified water, and mix well to obtain a microneedle inner layer solution, in which the dipeptidyl peptidase-4 inhibitor is encapsulated by the nanocellulose-based hydrogel to form vesicles.

[0055] 3. Place the outer layer solution of the microneedle into the molding cavity of the molding mold, vacuum pump for 19 minutes, air-dry in a vacuum drying oven for 4 hours, demold, and obtain the inner layer microneedle. Re-inject the outer layer solution into the molding cavity of the molding mold, and then insert the inner layer microneedle into the molding cavity containing the outer layer solution. After vacuum drying and demolding, the microneedle is obtained.

[0056] Example 5

[0057] A process for preparing microneedles for treating diabetes.

[0058] 1. Weigh 7.23 g of glucose kinase, 5.21 g of polyvinyl alcohol 03CP, 4.35 g of polyvinyl alcohol 30CP, 6.84 g of polyvinyl pyrrolidone K17, 9.62 g of hydroxyethyl cellulose, 2.56 g of sucrose, 3.92 g of sodium chloride, and 4.43 g of tris(hydroxymethyl)aminomethane, add 400 ml of purified water, and mix well to obtain a microneedle outer layer solution.

[0059] 2. Weigh 55.68 g of nanocellulose-based hydrogel, 16.83 g of dipeptidyl peptidase-4 inhibitor, 15.34 g of polyvinyl alcohol 03CP, 20.82 g of polyvinyl alcohol 30CP, 32.41 g of polyvinyl pyrrolidone K17, 39.73 g of hydroxyethyl cellulose, 12.58 g of sucrose, 18.32 g of sodium chloride, and 22.38 g of tris(hydroxymethyl)aminomethane, add 300 ml of purified water, and mix well to obtain a microneedle inner layer solution, in which the dipeptidyl peptidase-4 inhibitor is encapsulated by the nanocellulose-based hydrogel to form vesicles.

[0060] 3. Place the outer layer solution of the microneedle into the molding cavity of the molding mold, vacuum pump for 20 minutes, air-dry in a vacuum drying oven for 5 hours, demold, and obtain the inner layer microneedle. Re-inject the outer layer solution into the molding cavity of the molding mold, and then insert the inner layer microneedle into the molding cavity containing the outer layer solution. After vacuum drying and demolding, the microneedle is obtained.

[0061] Comparative Example 1

[0062] The experimental steps and experimental parameters of this comparative example are basically the same as those of Example 1, except that in this comparative example 1, no nanocellulose-based hydrogel vesicles are arranged outside the dipeptidyl peptidase-4 inhibitor in the inner layer solution of the microneedle.

[0063] Comparative Example 2

[0064] The experimental steps and experimental parameters of this comparative example are basically the same as those of Example 1, except that in this comparative example 2, insulin is encapsulated in the nanocellulose-based hydrogel vesicles.

[0065] Comparative Example 3

[0066] The experimental steps and experimental parameters of this comparative example are basically the same as those of Example 1, except that the microneedle outer layer solution of this comparative example 3 does not contain glucokinase.

[0067] The microneedles prepared above were tested:

[0068] The test method is as follows: 40 rats weighing (160±20)g were prepared and randomly divided into 8 groups, 5 rats in each group. After continuous feeding with high-fat and high-sugar feed for 4 weeks, the rats of different groups were respectively patched and administrated with the microneedles prepared above. During the administration period, each group was not restricted from eating or drinking. After patching, 4ml of blood was collected from the medial canthal sinus with a capillary glass tube every 30 minutes, centrifuged at 4°C, 3000rpm for 15 minutes, serum was drawn, stored in a low-temperature refrigerator, blood glucose and free fatty acid concentrations were tested and the corresponding data were recorded. The test was repeated 6 times. The average value of the data of each group of rats and the difference between the maximum and minimum values ​​of the blood glucose data were taken.

[0069] The test results obtained are entered in Table 1.

[0070] Table 1

[0071]

[0072]

[0073] Conclusion: From the test results of Table 1, it can be seen that the application of the microneedles of Examples 1-5 and Comparative Examples 1-3 to rats can significantly reduce the blood sugar level of rats. Although Comparative Examples 1 and 2 have better hypoglycemic effects, blood sugar fluctuations are large and cannot achieve a good stable control effect. It can be seen that the nanocellulose-based hydrogel vesicles can effectively and stably control blood sugar within a certain range under the action of glucose kinase. At the same time, the synergistic hypoglycemic effect of dipeptidyl peptidase-4 inhibitor and glucose kinase is better than that of glucose kinase and insulin. It can also be seen from Comparative Example 3 that the lack of glucose kinase will reduce the synergistic hypoglycemic effect of the drug on the one hand, and on the other hand, it cannot catalyze the conversion of glucose into 6-phosphate glucose, which leads to the slow dissolution of the nanocellulose-based hydrogel vesicles, further reducing the hypoglycemic effect.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A microneedle for treating diabetes, characterized in that: The components loaded in the microneedles include nanocellulose-based hydrogel, dipeptidyl peptidase-4 inhibitor, and glucokinase; The microneedle is a layered microneedle, comprising an inner layer and an outer layer; The solution forming the outer layer includes the glucokinase, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, sucrose, sodium chloride and tris(hydroxymethyl)aminomethane; The solution forming the inner layer includes nanocellulose-based hydrogel, dipeptidyl peptidase-4 inhibitor, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, sucrose, sodium chloride and tris(hydroxymethyl)aminomethane.

2. A microneedle for treating diabetes according to claim 1, characterized in that: The mass ratio of the nanocellulose-based hydrogel, the dipeptidyl peptidase-4 inhibitor, and the glucose kinase is (3-8): (5-10): (1-2).

3. A microneedle for treating diabetes according to claim 1, characterized in that: The nanocellulose-based hydrogel presents a vesicle structure and encapsulates the dipeptidyl peptidase-4 inhibitor therein.

4. The microneedle for treating diabetes according to claim 1, characterized in that: The dipeptidyl peptidase-4 inhibitor includes one or more of saxagliptin, vildagliptin, alogliptin and linagliptin.

5. The microneedle for treating diabetes according to claim 1, characterized in that: The preparation method of the nanocellulose-based hydrogel comprises the following steps: using a delignification method to obtain a wood cellulose skeleton in wood as a base material, softening it through an alkali treatment, and then compounding it with a polyacrylamide gel to obtain the nanocellulose-based hydrogel.

6. The microneedle for treating diabetes according to claim 1, characterized in that: The mass ratio of the outer layer to the inner layer of the microneedle is (1-2):(5-8).

7. A process for preparing a microneedle for treating diabetes according to any one of claims 1 to 6, characterized in that: The process comprises the following steps: firstly introducing the solution forming the inner layer into the molding mold, scraping the solution into the molding cavity of the molding mold by a scraper, demolding after vacuum drying to obtain the inner layer microneedles, re-injecting the outer layer solution into the molding cavity of the molding mold, and then inserting the inner layer microneedles into the molding cavity containing the outer layer solution, and obtaining the microneedles after vacuum drying and demolding.

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