An aggregate formed by the assembly of a chalcogen heterocyclic compound and insulin, a preparation method thereof, and an oral insulin preparation

Abstract

The present invention provides an aggregate, a preparation method thereof, and an oral insulin formulation. Specifically, an aggregate formed by the assembly of a chalcogen heterocyclic compound and insulin is provided. The aggregate can be further prepared into an oral insulin formulation. The oral formulation can be used to lower the blood glucose level of mammals and is used as part of a diabetes treatment regimen. The chalcogen heterocyclic compound in the oral insulin formulation prepared by this method can effectively protect insulin from overcoming the three major physiological barriers of the oral intake route, is stable in the gastrointestinal environment, and undergoes a dynamic chemical exchange reaction with the sulfhydryl groups of intestinal mucin in intestinal fluid and the proteins on the inner and outer sides of the epithelial cell membrane through the surface poly-chalcogen molecular bond, entering the circulatory system from intestinal epithelial cells and playing a role in lowering blood glucose. When the oral insulin formulation is administered orally, it has high bioavailability and good blood glucose lowering effect in mammals and can be used for the treatment of diabetes.

Description

Technical Field

[0001] The present invention relates to the field of biopharmaceutical technology, and particularly to an aggregate formed by a chalcogen heterocyclic compound and insulin, a preparation method thereof, and an oral insulin preparation. Background Art

[0002] Diabetes is a prevalent chronic disease that seriously threatens human life and health. Data from the latest edition of the International Diabetes Federation's Global Diabetes Map (9th Edition) shows that by 2019, 463 million people worldwide had diabetes. With the improvement of people's material living standards, changes in eating habits and lifestyles, the number of diabetes patients has been increasing year by year. It is estimated that the number of diabetes patients will jump to 700 million by 2045. Clinically, diabetes is mainly characterized by hyperglycemia. Persistent hyperglycemia and long-term metabolic disorders can lead to various complications, such as cardiovascular diseases, peripheral vascular diseases, neurological diseases, retinopathy, nephropathy and renal failure, ulcers and amputations, metabolic complications, oral complications, depression, etc., ultimately resulting in the loss of labor ability of patients, and even death or disability.

[0003] Insulin is the only hormone in the body that lowers blood sugar, and it has been used in the treatment of diabetes for a hundred years. Insulin is not only the first choice for the treatment of insulin-dependent type I diabetes, but also an adjuvant for the treatment of advanced type II diabetes. And clinical research data show that for newly diagnosed type II diabetes patients, early insulin intensive treatment can enable about half of the patients to obtain a 2-year clinical remission period, indicating that insulin is very important in the treatment of both type I and type II diabetes. Since its inception, the administration method of insulin for the treatment of diabetes has mainly been subcutaneous or intravenous injection, and patients need to inject 2 to 4 times a day, or even more times. For diabetes patients who need long-term medication, frequent insulin injection not only brings great pain and inconvenience to patients, but also the injection dose is not easy to control, which is extremely likely to cause large-scale blood sugar fluctuations. Long-term injection will also lead to many adverse reactions such as poor patient compliance, tissue necrosis at the injection site, microbial infection, insulinemia, nerve damage, etc. In addition, the insulin ingested by the injection method is inconsistent with the physiological delivery route of insulin secreted by the pancreas, and the liver cannot obtain the necessary insulin concentration to control blood sugar, which will lead to the occurrence of hyperinsulinemia. Therefore, researching and developing non-injectable insulin preparations that are convenient to use, safe and reliable has very important clinical significance for improving the health and quality of life of diabetes patients, and is also a major issue that the domestic and foreign pharmaceutical industries generally pay attention to.

[0004] Among different non-injection drug delivery methods, the oral administration route is the most traditional, convenient, and easily acceptable one for patients. Compared with injection preparations, oral administration preparations have lower requirements, stable storage, are convenient to carry and use, and have relatively low costs. In addition, taking insulin orally can better mimic the insulin secreted by the pancreas in terms of pharmacokinetics because they both enter the liver through the portal vein and then are transported to the peripheral circulation. However, insulin belongs to polypeptide drugs. Insulin oral preparations that enter the circulatory system through oral ingestion and play a hypoglycemic role need to overcome three major physiological barriers: (1) The strongly acidic environment in the stomach and digestive enzymes (such as pepsin, trypsin, peptidase, etc.) in the gastrointestinal tract can easily denature and degrade insulin, losing its biological activity; (2) The viscous glycoproteins in the gastrointestinal mucus layer form a dense network structure through disulfide bonds or non-covalent interactions, repelling and hindering the diffusion and penetration of insulin preparations, making it difficult for them to approach intestinal epithelial cells and restricting the absorption of insulin; (3) Compared with small molecule drugs, insulin has a larger molecular weight and a low efficiency of being absorbed by intestinal epithelial cells. The intercellular junction proteins between intestinal epithelial cells and the lysosomal degradation in cells will hinder insulin from entering the circulatory system through the paracellular or transcellular pathways, restricting the bioavailability of insulin.

[0005] To overcome these barriers and improve the bioavailability of insulin through oral ingestion, different embedding methods have been reported for preparing insulin oral preparations, but there are still a series of problems. First, the preparation methods of the currently reported insulin oral preparations are very complex and require a large number of chemical synthesis or physical treatment processes for the modification of insulin, the preparation of embedding agents, and the embedding of insulin. Second, in addition to the embedding agent and insulin, one or several additives such as absorption promoters, stabilizers, enzyme inhibitors, osmotic enhancers, pH regulators, mucin solubilizers or adhesives, and cell-penetrating peptides need to be added to assist in overcoming the three major physiological barriers of the oral ingestion route. These additives are likely to cause damage and infection to the normal physiological functions of the gastrointestinal tract, and a large number of systematic clinical studies are still needed on the biosafety issues. Third, a preparation contains multiple functional components, which not only increases the cost of insulin oral preparations but also leads to a decrease in the embedding rate of insulin. These factors limit the clinical promotion and use of insulin oral preparations. Therefore, there is an urgent need to develop a simple and effective insulin oral preparation that can simultaneously overcome the three major physiological barriers of the oral route, reduce the preparation cost, improve the pharmacokinetic and pharmacodynamic properties of oral insulin ingestion, and enhance the bioavailability and hypoglycemic effect of oral insulin. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide an aggregate formed by a chalcogen heterocyclic compound and insulin, a preparation method thereof, and an oral insulin preparation, which has a high bioavailability when administered orally.

[0007] The present invention provides an aggregate formed by the assembly of a chalcogen heterocyclic compound and insulin.

[0008] The chalcogen heterocyclic compound has the structure shown in Formula I:

[0009] A—L—B Formula I;

[0010] Wherein, A is a heterocyclic group containing two or more identical and / or different chalcogen atoms, and the chalcogen is sulfur (S), selenium (Se) or tellurium (Te);

[0011] B is a group that interacts with insulin molecules;

[0012] L is a linking group between A and B.

[0013] In the present invention, the heterocyclic group A may contain only one chalcogen element or a random combination of the above three chalcogen elements.

[0014] The heterocyclic group A is preferably a 4- to 100-membered ring.

[0015] Preferably, in the present invention, A has any of the following structures:

[0016]

[0017] In the present invention, L is a linking group (linker) between functional group A and functional group B.

[0018] Preferably, L is selected from carbon-carbon bond, carbon-boron bond, carbon-nitrogen bond, carbon-phosphorus bond, carbon-oxygen bond, carbon-sulfur bond, carbon-selenium bond, carbon-tellurium bond, metal coordination bond, borate bond, disulfide bond, ring-forming group, hydrogen bond, cleavable chemical bond, supramolecular host-guest interaction or ligand-receptor recognition interaction;

[0019] The above groups are the bonding modes of L with A or the bonding modes of L with B. The bonding mode of L with A and the bonding mode of L with B can be the same or different.

[0020] In the present invention, the functional group B and the insulin molecule are assembled into aggregates with the compound shown in Formula I through intermolecular interactions. The intermolecular force can be a covalent bond, a non-covalent bond, or both covalent and non-covalent bonds; the covalent bond can be one or more of an amide bond, an ester bond, a coordination bond, a click chemical bond, an ether bond, an ester amide, an imide bond, a borate ester bond, a disulfide bond, a carbon-carbon single bond, a carbon-carbon double bond, and a carbon-carbon triple bond; the non-covalent bond can be one or more of an electrostatic interaction, a van der Waals force, a hydrophobic interaction, a host-guest supramolecular interaction, a ligand-receptor recognition interaction, and a salt bridge bond.

[0021] Preferably, B is selected from one or more of a chemical / biological molecule that recognizes insulin, a DNA complementary strand, an aptamer, a polypeptide that forms a coiled coil / zipper structure / superstructure, and the following chemical groups:

[0022] More preferably, the chalcogen heterocyclic compound has the structure shown in Formula II:

[0023]

[0024] Wherein, X 1 、X 2 、X 3 、X 4 At least two of them are independently selected from S, Se or Te, and the rest are C;

[0025] R 1 、R 2 、R 3 Are independently selected from a carbon atom, an amide group or an imino group;

[0026] R 4 Is selected from a carboxyl group, an amino group,

[0027] n1, n2, n3, n4 are independently selected from any integer from 1 to 6.

[0028] In the above structural formula of the present invention, the curved line Indicates the connection position; the single bond “—” represents a methyl group.

[0029] The single bond of a cyclic group or an aromatic ring group, for example Respectively represent that a methyl group or an ethyl group can be connected to any position of the cyclic group or the aromatic ring group.

[0030] The substituent of a cyclic group or an aromatic ring group, for example Respectively represent that the substituent can be connected to any position of the cyclic group or the aromatic ring group.

[0031] In some specific embodiments of the present invention, the chalcogen heterocyclic compound is selected from one or more of the following structures:

[0032]

[0033] In the present invention, in the aggregate of insulin and the chalcogen heterocyclic compound, the chalcogen heterocyclic compound can be one kind, or two or more kinds.

[0034] The present invention has no special limitation on the type of the insulin, and it can be one or more of unmodified insulin, insulin analogs, and modified insulin.

[0035] Preferably, the unmodified insulin is selected from one or more of human insulin, human recombinant insulin, bovine insulin, porcine insulin, semi-synthetic insulin, and biosynthetic insulin.

[0036] Preferably, the insulin analogs are selected from one or more of insulin lispro, insulin glulisine, insulin aspart, insulin detemir, insulin glargine, and insulin degludec.

[0037] Preferably, the modified insulin is selected from one or more of chemically modified insulin, biomolecule-modified insulin, and genetically engineered insulin.

[0038] In the present invention, the types of the insulin include one or more of insulin, mealtime insulin, ultra-rapid-acting insulin, rapid-acting insulin, intermediate-acting insulin, long-acting insulin, and premixed insulin.

[0039] Preferably in the present invention, the molar ratio of the chalcogen heterocyclic compound to insulin is 1-200:1.

[0040] Preferably in the present invention, the particle size of the aggregate is 10-500 nm.

[0041] In the present invention, the above-mentioned aggregate of insulin and the chalcogen heterocyclic compound has high stability in simulated gastric and intestinal fluids, and can avoid the degradation and leakage of insulin in an acidic environment and a digestive enzyme environment.

[0042] The present invention provides a preparation method of the above-mentioned aggregate, comprising the following steps:

[0043] S1) Mix and incubate the insulin solution with the chalcogen heterocyclic compound solution, and form an aggregate through self-assembly.

[0044] Specifically, first, an insulin solution is mixed and incubated with a chalcogen heterocyclic compound solution for assembly to form aggregated colloidal particles; then, the free chalcogen heterocyclic compound and / or insulin that did not participate in the assembly to form aggregates is removed to obtain a suspension of the insulin-chalcogen heterocyclic compound assembled aggregates.

[0045] The time for the above-mentioned mixing and incubation is preferably 30 min.

[0046] During the above-mentioned mixing and incubation process, the chalcogen heterocyclic compound and insulin molecules can be assembled into aggregated colloidal particles with a particle size of 10 - 500 nm through intermolecular interactions, achieving the encapsulation of insulin, and the encapsulation efficiency is as high as ~70%.

[0047] The present invention has no special limitation on the method for removing the free chalcogen heterocyclic compound and / or insulin that did not participate in the assembly to form aggregates, and it can be a method well-known to those skilled in the art, including but not limited to dialysis or centrifugation.

[0048] The preparation method disclosed in the present invention has mild conditions and a simple method, and the prepared oral insulin preparation does not require other functional additives, and the cost is relatively low.

[0049] During the formation of the above-mentioned aggregates, the interaction between insulin and the chalcogen heterocyclic compound greatly increases its local concentration, the heterocyclic groups are closely close to each other, and a ring-opening polymerization reaction occurs to form a poly-chalcogen element molecular bond. Finally, the chalcogen heteroatom compound can exist in the form of monomers, short-chain oligomers, long-chain polymers, or a mixture of any two or more of the three compounds.

[0050] The present invention has no special limitation on the temperature, time, buffer solution, and solvent used in the above-mentioned aggregate assembly process, and they can be conditions well-known to those skilled in the art.

[0051] The present invention provides the application of the above-mentioned aggregates in the preparation of hypoglycemic drugs.

[0052] In the present invention, the aqueous suspension of the insulin-chalcogen heterocyclic compound aggregate can be directly administered orally to mammals.

[0053] Based on this, the present invention provides an oral insulin preparation, which includes the above-mentioned aggregates and pharmaceutically acceptable adjuvants.

[0054] The present invention has no special limitation on the dosage form of the oral preparation, and it can be an oral dosage form well-known to those skilled in the art.

[0055] The present invention can use pharmaceutically acceptable excipients to prepare the insulin and chalcogen heterocyclic compound aggregates into enteric-coated capsules, powders, tablets, granules, suspensions, dripping pills and other enteric preparations for oral administration; preferably, the dry powder of the insulin and chalcogen heterocyclic compound aggregates is combined with a pharmaceutically acceptable enteric-coated capsule and administered orally.

[0056] The present invention does not particularly limit the types of the adjuvants, and those skilled in the art can make corresponding selections according to the dosage form.

[0057] In the present invention, the poly-chalcogen element molecular bonds on the surface of the above insulin and chalcogen heterocyclic compound aggregates can undergo dynamic exchange chemical reactions with the sulfhydryl groups on the surface of mucin and other glycoproteins in the gastrointestinal tract, promoting the rapid penetration of the aggregates in the intestinal mucosal layer; the poly-chalcogen element molecular bonds include polysulfide bonds, polyselenide bonds, polytelluride bonds, and can be mixed poly-chalcogen element molecular bonds formed by more than one chalcogen element.

[0058] In the present invention, the insulin and chalcogen heterocyclic compound aggregates do not damage the tight junction proteins between epithelial cells. The poly-chalcogen elements on the surface of the aggregates can undergo dynamic exchange chemical reactions with the sulfhydryl groups on the surface of the epithelial cell membrane and enter the cytoplasm through a non-endocytic transcellular pathway, avoiding degradation by lysosomes; subsequently, through dynamic exchange chemical reactions with the sulfhydryl groups on the inner side of the epithelial cell membrane, they enter the circulatory system from the intestinal epithelial cells; this process promotes the absorption of insulin by epithelial cells, exerting a high bioavailability and a fast blood glucose lowering effect.

[0059] In the present invention, after the insulin and chalcogen heterocyclic compound assembled aggregates enter the blood circulation, they circulate to the hepatic sinus region through the portal vein and are depolymerized by glutathione at the hepatic sinus to release insulin, playing a role in lowering blood glucose. The depolymerization is an exchange reaction between glutathione and the poly-chalcogen element molecular bonds, resulting in the degradation of short-chain oligomers or long-chain polymers of chalcogen heteroatom compounds in the aggregates into monomers or shorter-chain oligomers, and unable to form stable aggregates.

[0060] The present invention provides a method for reducing the blood glucose level of mammals. After orally administering the suspension of the above insulin and chalcogen heterocyclic compound aggregates to mammals, or orally administering a composition of the dry powder (such as freeze-dried powder) of the above insulin and chalcogen heterocyclic compound aggregates and pharmaceutically acceptable excipients to mammals, the blood glucose concentration of mammals decreases.

[0061] In the present invention, the subject to which the oral insulin preparation is administered is a mammal, where the mammal includes but is not limited to mice, rats, rabbits, dogs, cats, sheep, pigs, cows, horses, monkeys, and humans; preferably, the subject is a human in need of reducing blood glucose, such as a patient suffering from diabetes.

[0062] In the present invention, a reduction in blood glucose in the mammal means that within 15 minutes after orally administering a therapeutically effective amount of insulin and a chalcogen heterocyclic compound aggregate to the mammal, the blood glucose of the mammal is reduced by at least 7%, preferably at least 30%. More preferably, after administering the aggregate to the mammal, throughout the period from 15 minutes to 840 minutes, the blood glucose concentration of the mammal is reduced by at least 30%, preferably at least 45%, and more preferably at least 75%.

[0063] In the present invention, there is no special limitation on the dosage of the insulin administered. The dosage of insulin varies depending on the species of the mammal, the weight of the mammal, the composition of the aggregate, the value of the desired blood glucose reduction, the physical condition, and other factors. In short, the amount of insulin can vary according to actual needs.

[0064] Therefore, the present invention provides a method for treating diabetes in patients in need of reducing blood glucose by orally administering the above-mentioned insulin oral preparation.

[0065] By orally administering the above oral preparation in the present invention, it is possible to reduce the blood glucose of a person in need of reducing blood glucose, such as a patient suffering from diabetes, to achieve a therapeutic effect.

[0066] In some specific embodiments of the present invention, the therapeutically effective amount of the insulin is 10 U - 1000 U of human recombinant insulin / ml of aggregate suspension.

[0067] In some specific embodiments of the present invention, the time required for the insulin oral preparation to enter the portal vein circulation is about 15 minutes or less.

[0068] In the present invention, the diabetes includes but is not limited to insulin-dependent impaired glucose tolerance, early diabetes, late diabetes, type I diabetes, type II diabetes, gestational diabetes, special type diabetes, etc.

[0069] The present invention provides a treatment method for treating diabetes and reducing the incidence of systemic hyperinsulinemia associated with long-term insulin use.

[0070] In the present invention, the administration time of the insulin oral preparation can be but is not limited to before meals, after meals, at night, or when blood glucose needs to be reduced.

[0071] In the present invention, the administration cycle of the above-mentioned oral insulin preparation to patients can be determined according to the state of disease development. For patients with chronic diabetes, it can be at least two weeks or longer. For patients with gestational diabetes, it can be administered throughout the pregnancy or during the period when blood glucose is unstable. For patients who require lifelong blood glucose control, it can be administered lifelong.

[0072] It should not be considered that the oral preparations used in the present invention are limited to the above-mentioned preferred embodiments. Other matrix materials, such as microporous particles, can be combined with the insulin and chalcogen heterocyclic compound aggregates to form an oral drug for oral administration.

[0073] In the present invention, the oral insulin preparation further comprises other therapeutic agents;

[0074] The other therapeutic agents are selected from subcutaneous injection hypoglycemic drugs and / or other oral hypoglycemic drugs.

[0075] That is, the oral insulin preparation described in the present invention can be used in combination with hypoglycemic drugs to achieve better hypoglycemic efficacy through combination therapy; the hypoglycemic drugs can be of subcutaneous injection type, including but not limited to glucagon-like peptide-1, glucagon-like peptide-1 receptor agonists (such as exenatide, liraglutide), glucose-dependent insulinotropic polypeptide; or can be of oral type, including but not limited to sulfonylurea drugs, meglitinide drugs, biguanides, α-glucosidase inhibitors, thiazolidinediones, dipeptidyl peptidase-4, etc.

[0076] In the present invention, the aggregates for the preparation of oral preparations of insulin or other protein-based drugs can be prepared by any suitable method. Preferably, the aggregates are prepared by the methods of any of the embodiments described herein, preferably but not necessarily.

[0077] In the present invention, preferably, the aggregate dry powder (such as freeze-dried powder) is combined with an enteric-coated capsule as a pharmaceutical composition, and the dose of insulin in the composition is used as a customized dose for oral administration to mammals. The size of the oral capsule used is related to the species of the mammals to be administered, because the pharyngeal sizes of different mammals are different.

[0078] In another preferred aspect of the present invention, the composition is placed in a container, and preferably the amount of insulin in the container is customized as a dose for single or multiple oral administrations to mammals. The container can be a container that meets the relevant regulations of pharmaceutical packaging materials and can accommodate oral capsules, such as blister packaging, plastic bottles, glass bottles, and / or other suitable containers, and is accompanied by an instruction manual.

[0079] It should be noted that the orally administered composition can also be pressed into tablets together with pharmaceutically acceptable excipients from the agglomerated dry powder and administered orally.

[0080] The present invention provides a customized-dose insulin oral preparation, which comprises an agglomerate formed by the assembly of the above insulin and a chalcogen heterocyclic compound, wherein the dose of insulin in the agglomerate is customized to the dose for oral administration to humans.

[0081] In some specific embodiments of the present invention, the above oral preparation comprises an aqueous suspension of an agglomerate formed by the assembly of insulin and a chalcogen heterocyclic compound, wherein the amount of insulin is a therapeutically effective amount.

[0082] In some specific embodiments of the present invention, the above oral preparation comprises a therapeutically effective amount of an agglomerate formed by the assembly of insulin and a chalcogen heterocyclic compound, a pharmaceutically acceptable coating and a capsule.

[0083] In some specific embodiments of the present invention, the above oral preparation can be a tablet prepared from a therapeutically effective amount of an agglomerate formed by the assembly of insulin and a chalcogen heterocyclic compound and pharmaceutically acceptable excipients.

[0084] In some specific embodiments of the present invention, the above oral preparation is loaded in a container, and the amount of insulin therein is customized to the dose for single or multiple oral administrations to humans.

[0085] Figure 1 It is a schematic diagram of the method process for preparing an insulin oral preparation from the chalcogen heterocyclic compound in the present invention and for reducing blood glucose by oral administration after loading an enteric-coated capsule. As Figure 1 shown, in the present invention, taking human recombinant insulin as an example, it self-assembles with a chalcogen heterocyclic compound to form an agglomerate. After being orally administered through an enteric-coated capsule and entering the gastrointestinal tract, in the small intestine, it directly enters the cytoplasm through the thiol exchange pathway, and then enters the blood from the intestinal epithelial cells again through the thiol exchange pathway, and circulates to the hepatic sinus through the portal vein. The polysulfide bond in the agglomerate is cleaved by glutathione in the hepatic sinus and in the blood to release insulin, playing a role in reducing blood glucose.

[0086] Compared with the prior art, the present invention provides an agglomerate, which is an agglomerate formed by the assembly of a chalcogen heterocyclic compound and insulin. The agglomerate can be further prepared into an insulin oral preparation. The insulin oral preparation has the following beneficial effects:

[0087] (1) The oral insulin preparation provided by the present invention is prepared by assembling insulin with a chalcogen heterocyclic compound to form an aggregate. In the chalcogen heterocyclic compound shown in Formula I, the B group interacts with insulin through intermolecular forces, causing the chalcogen heterocyclic compound shown in Formula I to approach closely, thereby increasing its local concentration, facilitating the ring-opening polymerization of the A group in the compound, and enabling the compound to exist in the form of monomers, short-chain oligomers, long-chain polymers, or a mixture of any two or more of these three compounds. Finally, a stable assembled aggregate colloidal particle is formed with insulin, realizing the encapsulation of insulin. This preparation process has mild conditions, a simple method, does not require other functional additives, and has a low production cost.

[0088] (2) The oral insulin preparation of the present invention is an aggregate self-assembled from insulin and a chalcogen heterocyclic compound. Compared with insulin oral preparations prepared by liposome encapsulation of insulin, amphiphilic insulin micelles, and other embedding methods, the assembled aggregate of insulin and the chalcogen heterocyclic compound has better stability under acidic conditions and in simulated gastrointestinal fluids, and can avoid degradation by the strong acidity of the stomach and gastrointestinal digestive enzymes.

[0089] (3) After the oral insulin preparation of the present invention enters the gastrointestinal tract of mammals, the poly-chalcogen molecular bonds on the surface of the aggregate can undergo dynamic exchange chemical reactions with the sulfhydryl groups on the surface of mucin and other glycoproteins in the gastrointestinal tract, promoting the rapid penetration of the aggregate in the intestinal mucosal layer; the assembled aggregate of insulin and the chalcogen heterocyclic compound does not damage the tight junction proteins between epithelial cells, and the poly-chalcogen molecular bonds on the surface can undergo dynamic exchange chemical reactions with the sulfhydryl groups on the surface of the epithelial cell membrane, entering the cytoplasm through a non-endocytotic transcytotic pathway and avoiding degradation by lysosomes; subsequently, through dynamic exchange chemical reactions with the sulfhydryl groups on the inner side of the epithelial cell membrane, it enters the circulatory system from the intestinal epithelial cells; it circulates through the portal vein to the hepatic sinus region, and is depolymerized by glutathione at the hepatic sinus to release insulin; this process promotes the absorption of insulin by epithelial cells, effectively mimics the physiological delivery pathway of pancreatic insulin secretion, exhibits a high bioavailability, a fast and long-lasting blood glucose lowering effect, and can be used for the treatment of diabetes.

[0090] (4) The aggregate self-assembled from insulin and the chalcogen heterocyclic compound of the present invention can be flexibly combined with different pharmaceutically acceptable excipients and forming technologies to prepare oral preparations in different forms such as enteric-coated capsules, powders, tablets, granules, suspensions, and dripping pills, facilitating the use of patients with different medication habits.

[0091] Therefore, the insulin oral preparation prepared with the chalcogen heterocyclic compound of the present invention can be more effectively used for the treatment of diabetes. Description of the Drawings

[0092] Figure 1Schematic diagram of the process for preparing an oral insulin preparation using a chalcogen heterocyclic compound in the present invention and oral administration for blood glucose lowering after loading into an enteric-coated capsule;

[0093] Figure 2 1H NMR spectrum of chalcogen heterocyclic compound 1;

[0094] Figure 3 Transmission electron microscopy image of the aggregate 1 formed by the assembly of insulin and chalcogen heterocyclic compound 1; Scale bar: 100 nm;

[0095] Figure 4 (a) Insulin release kinetic curves of the aggregate 1 formed by the assembly of insulin and chalcogen heterocyclic compound 1 in simulated gastrointestinal fluids and a glutathione-containing buffer solution; (b) Circular dichroism spectrum curve of insulin released from aggregate 1;

[0096] Figure 5 (a) Relationship curve between the transcellular transport efficiency of insulin and time of the aggregate 1 formed by the assembly of insulin and chalcogen heterocyclic compound 1 in an ex vivo intestinal model; (b) Relationship curve between the change in transepithelial electrical resistance and time of the single cell layer used in the ex vivo intestinal model after treatment with aggregate 1, free insulin, and sodium decanoate;

[0097] Figure 6 Curve of blood glucose level change over time in diabetic model mice after oral administration of a suspension of the aggregate 1 formed by the assembly of insulin and chalcogen heterocyclic compound 1, free insulin solution, normal saline, and subcutaneous injection of insulin;

[0098] Figure 7 Curve of blood glucose level change over time in diabetic model mice after oral administration of an enteric-coated capsule loaded with the lyophilized powder of the aggregate 1 formed by the assembly of insulin and chalcogen heterocyclic compound 1, an enteric-coated capsule loaded with lyophilized free insulin, and subcutaneous injection of insulin;

[0099] Figure 8 (a) After oral administration of an enteric-coated capsule loaded with the lyophilized powder of the aggregate 1 formed by the assembly of insulin and chalcogen heterocyclic compound 1 to diabetic model pigs; (b) Curve of blood glucose level change over time after oral administration of an enteric-coated capsule loaded with lyophilized free insulin. Arrows indicate feeding the diabetic model pigs at that time point;

[0100] Figure 9 1H NMR spectrum of chalcogen heterocyclic compound 4;

[0101] Figure 10 Transmission electron microscopy image of the aggregate 2 formed by the assembly of insulin and chalcogen heterocyclic compound 4; Scale bar: 100 nm;

[0102] Figure 11 Curves of blood glucose levels over time after oral administration of insulin assembled with chalcogen heterocyclic compound 4 to form an aggregate suspension, free insulin solution, normal saline, and subcutaneous injection of insulin to diabetic model mice;

[0103] Figure 12 Transmission electron microscopy image of aggregate 3 formed by the assembly of insulin and chalcogen heterocyclic compound 10; Scale bar: 100 nm;

[0104] Figure 13 Curves of blood glucose levels over time after oral administration of aggregate 3 formed by the assembly of insulin and chalcogen heterocyclic compound 10, free insulin solution, normal saline, and subcutaneous injection of insulin to diabetic model mice. Detailed Description of the Invention

[0105] To further illustrate the present invention, the following describes in detail the chalcogen heterocyclic compound provided by the present invention and the assembly formed with insulin in conjunction with examples.

[0106] The experimental supplies and related verification methods involved in the following detailed description are as follows:

[0107] (1) Chemical and biological reagents: The reaction reagents and organic solvents involved in the chemical synthesis of chalcogen heterocyclic compound 1 in the examples are all commercially available products and are purchased from the market. Ultrapure water is prepared by a Milli-Q water purification system (18.2 MΩ). Streptozotocin (STZ) is purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. Human recombinant insulin is purchased from Shanghai Yuanpei Biotechnology Co., Ltd. Intestinal mucin (from porcine stomach, type Ⅲ) is purchased from Sigma-Aldrich. Transwell membrane inserts are purchased from Corning. Mouse oral capsules and pig oral capsules are purchased from Torpac, USA. Enteric coating Eudragit L30 D-55 is purchased from Shanghai Changwei Pharmaceutical Excipients Co., Ltd.

[0108] (2) Cell lines and cell culture: Human colon cancer cell line Caco-2 is purchased from the Shanghai Institute of Cell Biology, Chinese Academy of Sciences. Caco-2 cells are cultured in MEM medium (Corning) supplemented with 20% fetal bovine serum (Hyclone) and 100 IU / mL penicillin-streptomycin at a final concentration, and cultured in an atmosphere containing 5% CO 2 2 at 37°C.

[0109] (3) Mammals: C57BL / 6J mice and Bama miniature pigs are purchased from Wu's Experimental Animal Company.

[0110] The insulin mentioned in the following examples is recombinant insulin, and the ratio of human recombinant insulin to the compound in the aggregate is the molar ratio.

[0111] Example 1

[0112] In Example 1, Compound 1 with the following structural formula was used:

[0113]

[0114] The synthesis steps of Compound 1 are as follows:

[0115]

[0116] First, Compound 2 and N,N'-carbonyldiimidazole were dissolved in dichloromethane solution, and then dropped into the dichloromethane solution containing ethylenediamine placed in an ice-water bath, stirred for 40 minutes, and then stirred at room temperature for 30 minutes; the reaction solution was washed with brine, the organic phase was dried by removing water with anhydrous sodium sulfate, and then concentrated under reduced pressure to obtain a yellow oil, yielding Compound 3. Compound 3 was dissolved in dichloromethane, 1H-pyrazole-1-carboximidamide hydrochloride was added, stirred at room temperature for 4 hours, the solvent was removed by distillation under reduced pressure, and the residue was dissolved in methanol, and then ether was added to induce precipitation. The solid was collected and washed with ether to obtain a light yellow solid, which is Compound 1 described in this experiment.

[0117] The structure of the product was characterized by nuclear magnetic resonance, and the results are as Figure 2 shown.

[0118] Method for preparing an oral insulin preparation using the chalcogen heterocyclic compound 1 and its characterization: (1) Recombinant human insulin and the chalcogen heterocyclic compound 1 were mixed and incubated in 20 mM Tris-HCl, pH 7.0 buffer at a molar ratio of 1:50 for 30 minutes; (2) The suspension obtained in the first step was dialyzed or centrifuged to remove unreacted free insulin, free Compound 1, and free oligomers, obtaining an assembled aggregate of insulin and the chalcogen heterocyclic compound 1. Although not wishing to be bound by a particular theory, based on experimental studies, the inventors believe that in this method, the electrostatic or / and salt bridge interaction between the positively charged guanidyl group of Compound 1 and the carboxyl group of insulin brings Compound 1 closely together, increasing the local effective concentration of Compound 1, thereby facilitating the ring-opening polymerization of the chalcogen heterocyclic functional group to form oligomers, and at the same time self-assembling with insulin to form an aggregate, achieving the encapsulation of insulin.

[0119] As Figure 3 shown, the average particle size of the aggregates prepared in this example observed under a transmission electron microscope was ~50 nm, and the encapsulation efficiency of insulin reached ~70%.

[0120] Study on the insulin release kinetics of the aggregation of insulin and the chalcogen heterocyclic compound under different conditions:

[0121] (1) Disperse the FITC-labeled aggregates in simulated gastric fluid, simulated intestinal fluid, and a physiological buffer solution with a glutathione concentration of 7 mM at the sinusoids of the liver, and place them in the dialysis cup of a microdialysis device. An isotonic solution is placed in the receiving tube of the microdialysis device. (2) At the designated time points, take out 50 μL of the solution from outside the dialysis cup and replenish an equal amount of solution into the microdialysis device. (3) Dilute 50 μL of the solution to 200 μL, measure the fluorescence intensity of the solution and the standard curve with a fluorescence spectrophotometer, and determine the insulin release amount at each time point.

[0122] As Figure 4 shown in a, almost no insulin was released from the aggregates during incubation in simulated intestinal fluid for 12 hours; there was a slow and small amount of release in simulated gastric fluid; in the physiological buffer solution containing 7 mM glutathione, insulin could be rapidly released. In addition, as Figure 4 shown in b, circular dichroism characterization found that insulin maintained its intact secondary structure after release, which is one of the signs of maintaining insulin bioactivity. Simulated gastric fluid and simulated intestinal fluid are commonly used as models to study the stability of oral preparations after oral administration. The experimental results show that the aggregates obtained in this example can remain stable in the gastrointestinal environment.

[0123] Transcellular transport of insulin and chalcogen heterocyclic compound aggregates in an in vitro intestinal model and integrity of the epithelial cell layer:

[0124] (1) Seed Caco-2 cells into 24-well Transwell culture inserts, culture for 21 days, and use a Millicell resistance meter to detect the transepithelial electrical resistance (TEER) of the cell monolayer. When it is greater than 300 Ω·cm 2 , it indicates that tight junctions are formed between Caco-2 cells, and the in vitro intestinal epithelial cell monolayer model is successfully constructed. (2) Add 20 μg / mL of the aggregates to the upper chamber of the Transwell. Every 1 hour, take the liquid from the lower chamber of the Transwell to measure the insulin concentration and measure the TEER, and continuously monitor for 12 hours.

[0125] Experimental results: As Figure 5 shown in a, the efficiency of transcellular transport of human recombinant insulin and chalcogen heterocyclic compound aggregates is ~43%, but almost no trans-epithelial cell transport was observed in the control experiment using free human recombinant insulin.

[0126] As Figure 5As shown in Figure b, experiments found that the aggregates did not cause a significant change in TEER, indicating that the transcellular transport of aggregates did not disrupt the tight junctions between cells and did not follow the paracellular pathway. To better illustrate the integrity of the epithelial cell layer, the permeation enhancer sodium caprylate was added in the control experiment, and a sharp decrease in TEER was found, indicating that the integrity of the epithelial cell layer was disrupted.

[0127] Study on the change of blood glucose in vivo after oral administration of insulin and chalcogen heterocyclic compound aggregate suspension to diabetic model mice:

[0128] (1) C57BL / 6J mice aged 6 - 8 weeks were intraperitoneally injected with streptozotocin (STZ) for five consecutive days to induce damage to their pancreatic islet B cells. On the 17th day after the first injection, the blood glucose concentration of the mice was measured, and those with a blood glucose concentration higher than 300 mg / dL were considered to have successfully established a diabetic mouse model. (2) After orally administering 80 U / kg dose of insulin to the diabetic model mice with the aggregate suspension obtained above, blood was taken from the tail vein of the mice at different time points to monitor the change of blood glucose. As control experiment 1, the diabetic model mice were orally administered the same dose of free insulin. As control experiment 2, the diabetic model mice were orally administered the same volume of normal saline. As control experiment 3, the diabetic model mice were subcutaneously injected with 5 U / kg insulin.

[0129] Experimental results: As Figure 6 shown, after oral administration of the aggregates, the diabetic model mice showed a significant decrease in blood glucose within 15 minutes, and the significant decrease in blood glucose was about 20%. After 60 minutes, the blood glucose decreased by about 30%. During the entire period from 15 minutes to 600 minutes, the blood glucose concentration of the diabetic model mice decreased by 66%. In control experiments 1 and 2, the blood glucose values of the diabetic model mice administered free insulin or normal saline basically did not decrease. In control experiment 3, after subcutaneous injection of insulin to the diabetic model mice for 15 minutes, a significant decrease in blood glucose was shown, but the duration of maintaining the blood glucose decrease was relatively short, and only a 30% - 50% decrease was shown during the period from 15 minutes to 180 minutes.

[0130] The above results indicate that after the aggregate suspension enters the gastrointestinal tract, insulin can be effectively protected from the strong acidity and digestive enzymes in the gastrointestinal environment after being embedded by the chalcogen heterocyclic compound on its surface. Moreover, the poly-chalcogen molecular bonds on the surface of the aggregate can undergo dynamic exchange chemical reactions with the sulfhydryl groups on the surface of the epithelial cell membrane, entering the cytoplasm through a non-endocytic transcytosis pathway and avoiding degradation by lysosomes. Subsequently, through dynamic exchange chemical reactions with the sulfhydryl groups on the inner side of the epithelial cell membrane, it enters the circulatory system from the intestinal epithelial cells; it circulates through the portal vein to the hepatic sinus region, where it is depolymerized by glutathione at the hepatic sinus and releases insulin; this process promotes the absorption of insulin by epithelial cells and has a high bioavailability; after these processes, this oral insulin preparation exerts a relatively fast and long-lasting hypoglycemic effect.

[0131] Study on the change of blood glucose in vivo after oral administration of insulin and chalcogen heterocyclic compound aggregates loaded in enteric-coated capsules to diabetic model mice:

[0132] (1) The obtained aggregates were made into freeze-dried powder and filled into enteric-coated capsules; as control experiment 1, an equal dose of free insulin was filled into enteric-coated capsules. (2) For the diabetic model mice constructed by the same method as above, after oral administration of recombinant insulin at a dose of 20 U / kg, blood was taken from the tail vein of the mice at different time points to monitor the change of blood glucose. As control experiment 2, diabetic model mice were subcutaneously injected with 5 U / kg insulin.

[0133] Experimental results: As Figure 7 shown, after oral administration of the aggregates, the diabetic model mice showed a significant decrease in blood glucose within 30 minutes, and the significant decrease in blood glucose was about 30%, and the blood glucose decreased by about 45% after 60 minutes; during the entire period from 30 minutes to 600 minutes, the blood glucose concentration of the diabetic model mice decreased by about 75%. In control experiment 1, for the diabetic model mice orally administered with enteric-coated capsules loaded with insulin, the blood glucose value basically did not decrease. In control experiment 2, the mice showed a significant decrease in blood glucose 15 minutes after subcutaneous injection of insulin, but the time to maintain the decrease in blood glucose was relatively short, and only showed a 30% - 50% decrease during the period from 15 minutes to 180 minutes.

[0134] Study on the change of blood glucose in vivo after oral administration of insulin and chalcogen heterocyclic compound aggregates loaded in enteric-coated capsules to diabetic model pigs:

[0135] (1) Intravenous perfusion of 150 mg / kg streptozotocin (STZ, with a concentration of 75 mg / mL) was performed on 4-month-old Bama minipigs to induce damage to their pancreatic islet B cells. On the 7th day after the first injection, the blood glucose concentration of the pigs was measured. A blood glucose concentration higher than 300 mg / dL was considered successful in constructing a diabetic pig model. (2) The obtained aggregates were made into freeze-dried powders and filled into enteric-coated capsules; as Control Experiment 1, an equal dose of free insulin was filled into enteric-coated capsules. (3) After orally administering 20 U / kg of insulin to the diabetic model pigs, blood was taken from the jugular vein of the pigs at different time points to monitor the changes in blood glucose. (4) At 3 hours and 8 hours after taking the medicine, the diabetic model pigs were given normal food, and the food bowls were removed 15 minutes later.

[0136] The experimental results, as Figure 8 shown, the diabetic model pigs showed a significant decrease in blood glucose within 30 minutes, and the significant decrease in blood glucose was about 7%. The blood glucose decreased by 35% after 60 minutes; during the entire period from 30 minutes to 840 minutes, the blood glucose concentration of the diabetic model pigs showed a decrease; the blood glucose increased after two meals during the experiment and then showed a decrease; the decrease in blood glucose was 55% - 60%. In Control Experiment 1, the blood glucose value of the diabetic model pigs orally administered free insulin loaded in enteric-coated capsules basically did not decrease.

[0137] Example 2

[0138] Compound 4 with the following structural formula was used in Example 2.

[0139]

[0140] The synthesis of Compound 4 described in the present invention is as follows:

[0141]

[0142] Compound 4 was prepared from Compound 3. Hydrochloric acid and absolute ethanol were mixed and stirred until homogeneous. Compound 3 was added to the solution, and an equimolar equivalent of dicyandiamide was added. The mixture was heated under reflux with constant stirring for 12 hours. Column chromatography was performed to obtain Compound 4.

[0143] The structure of the product was characterized by nuclear magnetic resonance, and the results are as Figure 9 shown.

[0144] Method and Characterization for Preparing Oral Insulin Preparation Using Chalcogen Heterocyclic Compound 4: (1) Recombinant human insulin and chalcogen heterocyclic compound 4 were mixed and incubated in 20 mM Tris-HCl, pH 7.0 buffer at a molar ratio of 1:50 for 10 minutes; (2) The suspension obtained in the first step was dialyzed or centrifuged to remove unreacted free insulin, free compound 4 and free oligomers, and the assembled aggregate 2 of insulin and chalcogen heterocyclic compound 4 was obtained.

[0145] As Figure 10 shown, the particle size of the aggregate 2 prepared in this example observed under a transmission electron microscope was 30 - 50 nm, and the encapsulation efficiency of insulin reached ~70%.

[0146] Study on the change of blood glucose in diabetic model mice after oral administration of the suspension of the aggregate of insulin and chalcogen heterocyclic compound: After oral administration of the suspension of the aggregate 2 obtained above to diabetic model mice at a dose of 50 U / kg of insulin, blood was taken from the tail vein of the mice at different time points to monitor the change of blood glucose; as control experiment 1, an equal volume of normal saline was orally administered to diabetic model mice; as control experiment 2, 5 U / kg of insulin was subcutaneously injected into diabetic model mice.

[0147] Experimental results: As Figure 11 shown, after oral administration of the aggregate 2, diabetic model mice showed a significant decrease in blood glucose within 30 minutes, and the significant decrease in blood glucose was about 20%, and the blood glucose decreased by about 30% after 60 minutes; within the entire period from 15 minutes to 600 minutes, the blood glucose concentration of diabetic model mice decreased by about 50%. In control experiment 1, the blood glucose value of diabetic model mice administered with normal saline did not basically decrease. In control experiment 2, after subcutaneous injection of insulin into diabetic model mice for 15 minutes, a significant decrease in blood glucose was shown, but the time to maintain the decrease in blood glucose was relatively short, and only within the period from 15 minutes to 180 minutes, a decrease of 30% - 50% was shown.

[0148] Example 3

[0149] In Example 3, compound 10 with the following structural formula was used,

[0150]

[0151] The synthesis of compound 10 described in the present invention is as follows:

[0152]

[0153] First, prepare selenoic acid 8. Add compound 5 into a round-bottom flask, and then successively add absolute ethanol, 2 molar equivalents of sodium hydroxide and water. React at 50 °C for 2 hours to obtain compound 6. Dropwise add an aqueous solution of sodium diselenide using a syringe pump within 2 hours. During this process, maintain the temperature at 70 °C. After the addition is complete, keep reacting at 70 °C for 3 hours to obtain compound 7. Cool down to 40 °C, add activated carbon and stir for 30 minutes. Filter while it is hot to remove unreacted impurities and activated carbon. Place the filtrate on an ice-water mixture, cool it to 0 °C, and dropwise add 5% dilute hydrochloric acid under rapid stirring to adjust the pH to 2. A large amount of brownish solid precipitates. Filter by suction and dry to obtain compound 8 (selenoic acid).

[0154] Dissolve compound 8 and N,N'-carbonyldiimidazole in dichloromethane solution, and then dropwise add it to the dichloromethane solution containing ethylenediamine placed in an ice-water bath. Stir for 40 minutes, and then stir at room temperature for 30 minutes. Wash the reacted solution with brine. Dry the organic phase with anhydrous sodium sulfate to remove water, and then perform vacuum concentration to obtain a yellow oil, which is compound 9. Subsequently, mix hydrochloric acid and absolute ethanol and stir until homogeneous. Add compound 9 to the solution, and then add an equimolar amount of dicyandiamide. Heat the mixture under constant stirring and reflux for 12 hours. Purify by column chromatography to obtain compound 10.

[0155] The structure of the product was verified by nuclear magnetic resonance spectroscopy.

[0156] Method for preparing an oral insulin formulation using the chalcogen heterocyclic compound 10 and its characterization: (1) Mix and incubate recombinant human insulin and the chalcogen heterocyclic compound 10 at a molar ratio of 1:50 in 20 mM Tris-HCl buffer at pH 7.0 for 10 minutes; (2) Dialyze or centrifuge the suspension obtained in the first step to remove unreacted free insulin, free compound 10, and free oligomers, to obtain the assembled aggregate 3 of insulin and the chalcogen heterocyclic compound 10.

[0157] As Figure 12 shown, the particle size of the aggregate 3 prepared in this example observed under a transmission electron microscope is ~50 nm, and the encapsulation efficiency of insulin reaches ~65%.

[0158] Study on the change of blood glucose in vivo after oral administration of the insulin and chalcogen heterocyclic compound aggregate suspension to diabetic model mice: After orally administering the aggregate 3 suspension obtained above to diabetic model mice at a dose of 50 U / kg of insulin, take blood from the tail vein of the mice at different time points to monitor the change of blood glucose; as control experiment 1, orally administer an equal volume of normal saline to diabetic model mice; as control experiment 2, subcutaneously inject 5 U / kg of insulin to diabetic model mice.

[0159] Experimental results: AsFigure 13 As shown, after oral administration of the aggregate 3, the diabetic model mice showed a significant decrease in blood glucose within 30 minutes, and the significant decrease in blood glucose was about 20%. After 60 minutes, the blood glucose decreased by about 30%. During the entire period from 15 minutes to 600 minutes, the blood glucose concentration of the diabetic model mice showed about 55%. In Control Experiment 1, for the diabetic model mice administered with physiological saline, the blood glucose value basically did not decrease. In Control Experiment 2, after subcutaneous injection of insulin into the diabetic model mice for 15 minutes, a significant decrease in blood glucose was shown, but the time for maintaining the decrease in blood glucose was relatively short, and only a 30% - 50% decrease was shown during the period from 15 minutes to 180 minutes.

[0160] Since mammals such as mice and pigs are commonly used models for humans in drug tests, it can be demonstrated that compositions such as suspensions, enteric-coated capsules, powders, tablets, granules, pills, etc. containing aggregates of insulin and chalcogen heterocyclic compounds can effectively reduce the blood glucose level of humans when orally administered, and are particularly useful for the treatment of diabetic patients.

[0161] Therefore, the method for preparing an oral insulin preparation using a chalcogen heterocyclic compound is simple and has a low cost. Moreover, it significantly improves the pharmacokinetic and pharmacodynamic properties of oral administration of insulin, has a high bioavailability and a good blood glucose-lowering effect, and has broad application prospects in the treatment of diabetes.

[0162] The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. An oral insulin preparation, comprising an aggregate and a pharmaceutically acceptable adjuvant; the aggregate is an aggregate formed by the assembly of a chalcogen heterocyclic compound and insulin; The chalcogen heterocyclic compound has any one of the following structures:

2. The oral insulin preparation according to claim 1, wherein, the insulin is selected from one or more of unmodified insulin and insulin analogs; the unmodified insulin is selected from one or more of human insulin, bovine insulin, porcine insulin, semi-synthetic insulin and biosynthetic insulin; the insulin analogs are selected from one or more of insulin lispro, insulin glulisine, insulin aspart, insulin detemir, insulin glargine, and insulin degludec.

3. The oral insulin preparation according to claim 2, wherein, the human insulin is human recombinant insulin.

4. The oral insulin preparation according to claim 1, wherein, the molar ratio of the chalcogen heterocyclic compound to insulin is 1 - 200:

1.

5. The oral insulin preparation according to claim 1, wherein, the particle size of the aggregate is 10 - 500 nm.

6. The preparation method of the aggregate of the oral insulin preparation according to claim 1, comprising the following steps: S1) Mix and incubate the insulin solution and the chalcogen heterocyclic compound solution, and form an aggregate through assembly.

7. The oral insulin preparation according to claim 1, wherein, the oral preparation is an enteric-coated capsule, powder, tablet, granule, suspension or dropping pill.

8. The oral insulin preparation according to claim 1, wherein, it further comprises other therapeutic agents; the other therapeutic agents are selected from other oral hypoglycemic drugs; the other oral hypoglycemic drugs are selected from one or more of glucagon-like peptide-1 receptor agonists, glucose-dependent insulinotropic polypeptide, sulfonylurea drugs, meglitinide drugs, biguanide drugs, α-glucosidase inhibitors, thiazolidinedione drugs, and dipeptidyl peptidase-4.

9. The oral insulin preparation according to claim 1, wherein, it further comprises other therapeutic agents; the other therapeutic agents are selected from other oral hypoglycemic drugs; the other oral hypoglycemic drug is selected from glucagon-like peptide-1.

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