阅读说明：本技术 强亲水型微针基材与载药微针及其在治疗疾病中的应用 (Strong hydrophilic microneedle substrate, drug-loaded microneedle and application of strong hydrophilic microneedle substrate and drug-loaded microneedle in treatment of diseases ) 是由 尹忠 于 2021-07-09 设计创作，主要内容包括：本发明公开了一种由强亲水型基材制成的微针,更具体地涉及一种使用聚乙烯醇和小分子多羟基化合物的组合物为基材,制备具有强亲水表面的微针与载药微针及其在治疗疾病中的应用。本发明使用多羟基高分子物质聚乙烯醇与小分子多羟基化合物配伍,可以获得具有强亲水性表面的微针,只要接触药物即可强力吸附药物、不易脱落、工艺简易、容易量产,载药量明显增高,药物使用效率高,空白微针制备与载药分阶段进行,载药阶段避免了高温,能有效地应用于治疗疾病的载药与释药,易于量产。本发明的微针基材组合物以及由此制成的空白微针以及使用空白微针载药,保持了聚乙烯醇固有的表面强亲水极性,使得包裹式载药的载药量和进入体内的透过量明显提高。(The invention discloses a microneedle made of a strong hydrophilic base material, and more particularly relates to a microneedle and a drug-loaded microneedle which are prepared by using a composition of polyvinyl alcohol and a small-molecule polyhydroxy compound as a base material and have strong hydrophilic surfaces, and application of the microneedle and the drug-loaded microneedle in treatment of diseases. The invention uses the compatibility of polyhydroxy high molecular substance polyvinyl alcohol and micromolecule polyhydroxy compound, can obtain the micro-needle with strong hydrophilic surface, can strongly adsorb the drug only by contacting the drug, is not easy to fall off, has simple process, easy mass production, obviously increases the drug-loading rate and has high drug use efficiency, the preparation of the blank micro-needle and the drug-loading are carried out in stages, the high temperature is avoided in the drug-loading stage, the invention can be effectively applied to the drug loading and drug release for treating diseases, and the mass production is easy. The microneedle substrate composition, the blank microneedle prepared from the microneedle substrate composition and the medicament carried by the blank microneedle keep the inherent strong surface hydrophilic polarity of polyvinyl alcohol, so that the medicament carrying amount of the encapsulated medicament carried and the penetration amount into the body are obviously improved.)

1. The strong hydrophilic microneedle base material composition is characterized by comprising a small molecular polyhydroxy compound and polyvinyl alcohol, wherein the hydroxyl ratio of the small molecular polyhydroxy compound to the polyvinyl alcohol is 0.1: 1-1.3: 1, the polymerization degree of the polyvinyl alcohol is 300-3500, and the alcoholysis degree is more than 80%.

2. A strongly hydrophilic microneedle substrate composition according to claim 1, wherein the degree of polymerization of the polyvinyl alcohol is 300 to 2600.

3. A strongly hydrophilic microneedle substrate composition according to claim 1, wherein the degree of alcoholysis of the polyvinyl alcohol is 88% or more.

4. A strongly hydrophilic microneedle substrate composition according to claim 1, wherein the ratio of the small molecule polyol to the polyvinyl alcohol is 0.15:1 to 1: 1.

5. A strongly hydrophilic microneedle substrate composition according to claim 1, characterised in that the small molecule polyol is selected from one or more of glycerol, erythritol, threitol, xylitol, arabitol, ribitol, sorbitol, mannitol, galactitol, iditol, heptatol, ribose, xylose, glucose.

6. A strongly hydrophilic microneedle substrate composition according to claim 1, characterised in that the small molecule polyol is selected from one or more of glycerol, erythritol, xylitol, sorbitol, mannitol.

7. A strongly hydrophilic microneedle, characterized in that the microneedle base is a strongly hydrophilic microneedle base composition according to any one of claims 1 to 6.

8. A strongly hydrophilic microneedle substrate characterized in that a strongly hydrophilic microneedle substrate composition according to any one of claims 1 to 6 is mixed as a blended powder, or a strongly hydrophilic microneedle substrate composition according to any one of claims 1 to 6 is mixed and hot-pressed into a shape, or a strongly hydrophilic microneedle substrate composition according to any one of claims 1 to 6 is melt-extruded into a shape by using a blending machine.

9. A preparation method of a strong hydrophilic microneedle is characterized by comprising the following steps:

a) the strongly hydrophilic microneedle substrate composition according to any one of claims 1 to 6, blended at room temperature to form a blended powder;

b) hot-pressing the blended powder into a molding material, and hot-pressing the molding material into a mold to form a blank microneedle; or the blended powder is thermally mixed and melted by a blending machine at a certain temperature and extruded into a section material, and the section material is thermally pressed into a die to form the blank microneedle.

10. A method for preparing a microneedle with strong hydrophilicity according to claim 9, characterized in that the mold is a flat plate having one or more groups of micro-holes arrays, the micro-holes are through holes, and the thickness of the flat plate is 0.2-3 mm; and hot-pressing the molding material into a mold to form the blank micro-needle, namely adding the blended powder or the molding material above the micropore array of the mold plate, heating to form a molten flow with fluidity, and applying pressure from the upper part of the material downwards, or vacuumizing from the lower part of the mold to reduce pressure, or applying pressure from the upper part and vacuumizing from the lower part simultaneously to make the molten flow enter the micropores of the mold.

11. The method for preparing a microneedle having a strong hydrophilicity according to claim 10, wherein the pressure is 28 to 32kg/cm²And the hot pressing or hot mixing and dissolving temperature is from the lower limit temperature of the base material forming to the decomposition temperature of polyvinyl alcohol.

12. A drug-loaded microneedle characterized in that the drug-loaded microneedle is formed by contacting and adsorbing a solution containing a drug on the tip surface of the strongly hydrophilic microneedle according to claim 7 and drying the drug-loaded microneedle.

13. The drug-loaded microneedle according to claim 12, wherein the drug is a protein drug, a polypeptide drug, or a small molecule drug.

14. A drug-loaded microneedle according to claim 13, in which the drug is one of insulin, exenatide, human growth hormone, finasteride.

15. A drug-loaded microneedle according to claim 12, in which the drug-containing solution is formulated as an aqueous solution when the drug is water-soluble, or a solution or suspension prepared by uniformly suspending in water or dissolving/suspending in a polar solvent other than water when the drug is a water-insoluble drug.

16. The drug-loaded microneedle according to claim 12, wherein when the drug is water-soluble, the drug-containing solution is composed of the drug, povidone or polyvinyl alcohol, and water, wherein the concentration of povidone or polyvinyl alcohol is 0.5% -15%; when the active drug is water insoluble, the solution containing the drug consists of the drug, povidone poly or vinyl alcohol, water and/or non-aqueous polar solvent, wherein the concentration of the povidone or the polyvinyl alcohol is 4-15%; the non-aqueous polar solvent is one or a mixed solvent of methanol, ethanol and isopropanol.

17. A drug-loaded microneedle according to claim 12, characterized in that the contact adsorption process is: the drug-carrying microneedle is characterized in that a groove with the depth of 0.1-0.7 mm is formed in a flat plate, a solution containing drugs is added into the groove to a certain height, the needle point of the strong hydrophilic microneedle vertically faces downwards, stands in a circular groove and stays, and then is taken out and dried to obtain the drug-carrying microneedle.

18. A combined drug-loaded microneedle characterized in that two or more microneedles each carrying a different drug are combined integrally according to any one of claims 12 to 14.

19. The combined drug-loaded microneedle according to claim 18, wherein the combined drug-loaded microneedle is selected from insulin-loaded microneedles and exenatide drug-loaded microneedles, and the insulin-loaded microneedles and the exenatide drug-loaded microneedles are separately arranged.

20. An insulin-carrying microneedle, characterized by a drug-carrying microneedle according to any one of claims 12 to 15, wherein the drug is insulin.

21. A drug-loaded microneedle of exenatide, characterized in that the drug is exenatide according to any one of claims 12 to 15.

Technical Field

The invention relates to a microneedle made of a strong hydrophilic base material, in particular to a microneedle and a drug-loaded microneedle which are prepared by using a composition of polyvinyl alcohol and a small-molecular polyhydroxy compound as a base material and have strong hydrophilic surfaces and application thereof in treating diseases.

Background

The development of drug microneedles as drug-loaded delivery methods has been rapid in recent years, but the practical application of mass production is relatively slow. Although various prior arts are different in the preparation of microneedles and drug loading modes, the application is limited by the molding mode and the drug release mode of the microneedles.

The drug-carrying mode of the drug micro-needle mainly comprises two types, 1, mixed drug-carrying: uniformly mixing the drug and the microneedle base material powder into a whole, and processing the mixed material containing the drug into microneedles; 2. packaging type medicine carrying: firstly, independently processing a microneedle substrate material into a blank microneedle, and then loading a medicament to the tip part of the microneedle in a low-temperature environment. The two drug loading modes have advantages and disadvantages respectively, the mixed drug loading rate is not large enough, and the wrapped drug loading rate is smaller and even many times smaller; although the packaged drug-loading rate is smaller and easy to fall off, the loaded drug is positioned on the surface of the microneedle tip and directly contacts with human tissues, the drug release is fast and sufficient, the absorption is complete, and the drug consumption is saved; the medicine with mixed medicine carrying is embedded in the whole microneedle body, although the medicine carrying amount is higher than that of the wrapping type, only the medicine at the needle point part of the microneedle can enter human tissues, the medicine releasing process is blocked by the needle point base material, the medicine is slowly released, and more medicine which does not play the effect is remained at the far end of the needle body; the wrapped medicine is easy to fall off from the surface of the microneedle, and is also easy to be extruded after being extruded into the skin hole, and part of the medicine is pushed out of the skin. The easy falling off of the coated drug, small drug loading and extrusion out of the skin are generally caused by insufficient adhesion (affinity) between the surface of the microneedle and the drug.

The forming mode of the drug microneedle is generally two, 1, non-mold forming (such as a wire drawing method and a 3D printing method); 2. and (5) molding by using a mold. The mould molding mode has three types: 1. the hot injection method of the mixed materials, the medicine in the materials is subjected to higher temperature and can not be used for most protein polypeptide medicines; 2. the cold injection method of the mixed material concentrated solution can be carried out at low temperature and ensures the quality of the medicine, but the drying process consumes long time and the amplification of mass production is limited; 3. the hot-pressing cold-wrapping method is characterized in that a thermoplastic substrate is hot-pressed into blank microneedles, and then low-temperature wrapping medicine carrying is carried out.

In summary, the main technical problems of the drug microneedles are: the medicine carrying mode of the mixed material has low medicine utilization rate and poor comprehensive benefit; the drug loading is small, and particularly the wrapped drug loading is small and easy to fall off; many cases are subjected to high temperatures and are not suitable for many drugs; the process is complex, various conditions need to be precisely controlled, and mass production and amplification are difficult.

Disclosure of Invention

The invention provides a microneedle substrate composition capable of preparing microneedles by a relatively simple process flow, a blank microneedle prepared by using the substrate composition, and a drug loaded by using the blank microneedle in a contact manner, so that the microneedle substrate composition becomes a drug preparation form for treating diseases.

The invention adopts the following technical scheme:

the strong hydrophilic microneedle base material composition is composed of a small molecular polyhydroxy compound and polyvinyl alcohol, the hydroxyl ratio of the small molecular polyhydroxy compound to the polyvinyl alcohol is 0.1: 1-1.3: 1, the polymerization degree of the polyvinyl alcohol is 300-3500, and the alcoholysis degree is more than 80%.

The polymerization degree of the polyvinyl alcohol is 300-2600.

The alcoholysis degree of the polyvinyl alcohol is more than 88%.

The hydroxyl ratio of the micromolecular polyhydroxy compound to the polyvinyl alcohol is 0.15: 1-1: 1.

The small molecule polyhydroxy compound is selected from one or more of glycerol, erythritol, threitol, xylitol, arabitol, ribitol, sorbitol, mannitol, galactitol, iditol, heptanol, ribose, xylose and glucose.

The small molecular polyhydroxy compound is selected from one or more of glycerol, erythritol, xylitol, sorbitol and mannitol.

The microneedle substrate is the microneedle substrate composition with strong hydrophilicity.

The strong hydrophilic microneedle base material is prepared by mixing a strong hydrophilic microneedle base material composition into blended powder, or mixing and hot-pressing the strong hydrophilic microneedle base material composition into a profile, or hot-mixing and melting and extruding the strong hydrophilic microneedle base material composition into a profile by using a blending machine.

A preparation method of a strong hydrophilic microneedle is characterized by comprising the following steps:

a) blending the strongly hydrophilic microneedle substrate composition at room temperature to form blended powder;

b) hot-pressing the blended powder into a molding material, and hot-pressing the molding material into a mold to form a blank microneedle; or mixing the above powders

At a certain temperature, the mixture is heated, mixed, melted and extruded into a section by a blending machine, and the section is heated and pressed into a die to form a blank microneedle.

The die is a flat plate with one or more groups of micropore arrays, the micropores are through holes, and the thickness of the flat plate is 0.2-3 mm; and hot-pressing the molding material into a mold to form the blank micro-needle, namely adding the blended powder or the molding material above the micropore array of the mold plate, heating to form a molten flow with fluidity, and applying pressure from the upper part of the material downwards, or vacuumizing from the lower part of the mold to reduce pressure, or applying pressure from the upper part and vacuumizing from the lower part simultaneously to make the molten flow enter the micropores of the mold.

The pressure is 28-32kg/cm²And the hot pressing or hot mixing and dissolving temperature is from the lower limit temperature of the base material forming to the decomposition temperature of polyvinyl alcohol.

A drug-carrying microneedle is formed by contacting and adsorbing a solution containing a drug on the surface of a needle point of a strong hydrophilic microneedle and drying the solution.

The medicine is protein medicine, polypeptide medicine or small molecule medicine.

The medicine is one of insulin, exenatide, human growth hormone and finasteride.

The solution containing the drug is prepared into an aqueous solution when the drug is water-soluble, or is uniformly suspended in water or dissolved/suspended in a non-aqueous polar solvent to prepare a solution or suspension when the drug is a non-water-soluble drug.

When the medicine is water-soluble, the solution containing the medicine consists of the medicine, povidone or polyvinyl alcohol and water, wherein the concentration of the povidone or polyvinyl alcohol is 0.5-15%; when the active drug is water insoluble, the solution containing the drug consists of the drug, povidone poly or vinyl alcohol, water and/or non-aqueous polar solvent, wherein the concentration of the povidone or the polyvinyl alcohol is 4-15%; the non-aqueous polar solvent is one or a mixed solvent of methanol, ethanol and isopropanol.

The contact adsorption process comprises the following steps: the drug-carrying microneedle is characterized in that a groove with the depth of 0.1-0.7 mm is formed in a flat plate, a solution containing drugs is added into the groove to a certain height, the needle point of the strong hydrophilic microneedle vertically faces downwards, stands in a circular groove and stays, and then is taken out and dried to obtain the drug-carrying microneedle.

A combined drug-loading micro-needle is formed by combining two or more micro-needles of the drug-loading micro-needle which are respectively loaded with different drugs into a whole.

The drug-loading microneedle for combined administration is formed by combining an insulin drug-loading microneedle and an exenatide drug-loading microneedle, wherein the insulin drug-loading microneedle and the exenatide drug-loading microneedle are separately arranged.

An insulin drug-loaded microneedle, which is a drug-loaded microneedle, wherein the drug is insulin.

An exenatide drug-loaded microneedle, which is a drug-loaded microneedle, wherein the drug is exenatide.

Through a large number of theories and experimental researches, the invention is found that the micro-needle with strong hydrophilic surface can be obtained by using the compatibility of polyhydroxy high molecular substance polyvinyl alcohol and small molecular polyhydroxy compound, the micro-needle can strongly adsorb the medicine only by contacting the medicine, is not easy to fall off, has simple process, easy mass production, obviously increased medicine-carrying amount and high medicine use efficiency, the preparation of the blank micro-needle and the medicine-carrying are carried out in stages, the high temperature is avoided in the medicine-carrying stage, the micro-needle can be effectively applied to medicine carrying and medicine release for treating diseases, and the mass production is.

The microneedle substrate composition, the blank microneedle prepared from the microneedle substrate composition and the drug loading method using the blank microneedle provide a microneedle drug delivery scheme for treating diseases, and have the following remarkable characteristics and beneficial effects:

the microneedle composition substrate of the invention utilizes the ratio of the small-molecule polyhydroxy compound and the polyvinyl alcohol to adjust the physical property, improves the thermoplasticity of the polyvinyl alcohol and achieves the result that the thermoplastic temperature is greatly lower than the decomposition temperature.

And secondly, the inherent surface strong hydrophilic polarity of the polyvinyl alcohol is maintained, so that the drug-loading rate of the wrapped drug-loading and the penetration amount into the body are obviously improved.

Thirdly, as the medicine carrying is carried out by hydrophilic polar adsorption, the preparation of the blank micro-needle and the medicine carrying can be carried out step by step, and the medicine carrying process can be carried out at a low temperature above zero, so that the quality of the medicine is ensured, and the micro-needle is suitable for the micro-needle administration of a plurality of medicines, particularly the medicines sensitive to temperature such as protein polypeptides and the like;

fourthly, the medicine is wrapped on the surface of the needle tip and directly contacts with the intradermal tissue, so that the effect is fast, the utilization rate is high, and the cost advantage is achieved;

fifthly, the needle body has proper hardness, high administration precision and mild skin feel;

sixthly, the micro-needle substrate has good toughness, meets the stress requirement of machining, and has the advantages of simple process, simple and convenient operation, extremely short time consumption and great process amplification potential.

These remarkable features and benefits are all based on the attribute features of the microneedle composition related to the present invention, namely: 1. biological safety; 2. the surface has strong adhesiveness; 3. good thermoplasticity; 4. specific affinity relation with aqueous solution; 5. good cold shrinkage and toughness; 6. and (4) natural degradability. Based on the attribute characteristics, the microneedle composition substrate strongly supports the medicinal prospect, the industrial mass production prospect and the environmental protection requirement of the medicinal microneedle.

Drawings

Fig. 1 is a schematic view of a dedicated microneedle preparation apparatus;

FIG. 2 is a schematic view of a mold plate;

FIG. 3 is a schematic view of a process for preparing microneedles after blending powder directly into a profile;

FIG. 4 is a schematic flow chart of preparing microneedles by extruding the blended powder into a profile through thermal blending of an apparatus;

FIG. 5 is a schematic view of the process of manufacturing microneedles by preheating the device to a molding temperature and then placing the device in a mold material for hot pressing;

fig. 6 is an image under high magnification (30 times) of a blank microneedle of the invention;

fig. 7 is a schematic view of a blank microneedle of the present invention;

FIG. 8 is an image of the blank microneedle of the present invention after loading drug firmly adsorbed at the needle tip under a high magnification magnifier (30 times);

fig. 9 is a schematic view of a drug-loaded microneedle of the present invention;

fig. 10 is a schematic view of a state that a microneedle hangs a liquid medicine to wrap a tip of a microneedle;

FIG. 11 is a mannitol standard hydrogen spectrum;

FIG. 12 is a self-measured hydrogen spectrum of commercial polyvinyl alcohol 1788;

FIG. 13 is a hydrogen spectrum of a polyvinyl alcohol 1788/mannitol (1:0.6185w/w) microneedle sheet;

FIG. 14 is a hydrogen spectrum of a polyvinyl alcohol 1788/mannitol (1:0.6185w/w) microneedle sheet aqueous solution with a majority of polyvinyl alcohol precipitated by copper ions;

FIG. 15 is a hydrogen spectrum of a polyvinyl alcohol 1788/mannitol (1:0.6185w/w) microneedle sheet aqueous solution with predominantly precipitated copper ions and predominantly precipitated mannitol in the supernatant;

FIG. 16 is a 1799 self-measured hydrogen spectrum of commercially available polyvinyl alcohol;

FIG. 17 is a hydrogen spectrum of a polyvinyl alcohol 1799/mannitol (1:0.689w/w) microneedle sheet;

FIG. 18 is a hydrogen spectrum of an aqueous solution of polyvinyl alcohol 1799/mannitol (1:0.689w/w) microneedle sheet with copper ion precipitation partially dominated by polyvinyl alcohol;

FIG. 19 is a hydrogen spectrum of aqueous solutions of polyvinyl alcohol 1799/mannitol (1:0.689w/w) microneedle sheets after precipitation of copper ions, predominantly mannitol in the supernatant;

fig. 20 is a schematic view of a combination microneedle;

FIG. 21 is a pharmacodynamic graph of insulin microneedles in a diabetes model pig;

FIG. 22 is a diabetes model swine pharmacodynamic plot of exenatide microneedles;

fig. 23 is a pre-fabricated disc and/or microneedle moulding temperature table for different hot extruded materials;

FIG. 24 is a table of the composition of the blended powders, i.e., profiles, tested;

FIG. 25 is a table of adhesion test results for base materials to spot formation of sodium chloride/povidone solution;

FIG. 26 is a table of results of the amount of test solution adsorbed by the microneedles;

FIG. 27 is a table showing the state where the drop of the drug is caught by the needle tip under observation with a high magnification magnifier (30 times);

FIG. 28 is a table of drug shedding observed with a high magnification magnifier (30 times) after one meter high free fall;

fig. 29 is a table of toughness versus friability results for microneedle substrates;

fig. 30 is a test solution scale for microneedle adsorption of water soluble material;

fig. 31 is a test solution scale for microneedle adsorption of water insoluble materials;

FIG. 32 is a table of drug effect tests of insulin-loaded microneedles;

fig. 33 is a drug efficacy test table of exenatide drug loaded microneedles;

FIG. 34 is a table of blended powder material pressed directly into a disc shape;

FIG. 35 is a table of extruded pellets pressed into disc-shaped pellets;

FIG. 36 is a table of needle integrity as microneedles of five different formulations are detached from the mold plate;

FIG. 37 is a table of hot melt purge of mannitol/XX 99 polyvinyl alcohols of different degrees of polymerization;

FIG. 38 is a table of experimental results for morphology retention in skin pores of needles of different alcoholysis levels of materials.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.

The following description of the embodiments of the present invention will be made with reference to the accompanying drawings, but the present invention is not limited thereto.

The invention firstly provides a strong hydrophilic microneedle base material composition which is composed of polyvinyl alcohol and micromolecular polyhydroxy compounds, wherein the hydroxyl ratio of the micromolecular polyhydroxy compounds to the polyvinyl alcohol is 0.1: 1-1.3: 1, the polymerization degree of the polyvinyl alcohol is 300-3500, and the alcoholysis degree is more than 80%.

The polymerization degree in the present invention refers to the total number of structural units in a polymer molecule, i.e., how many structural units are polymerized to form a polymer. Polyvinyl alcohol is generally obtained by polymerization and alcoholysis of vinyl acetate, wherein vinyl acetate units are subjected to alcoholysis to form vinyl alcohol units, wherein a portion of the alcoholysis is carried out, and a portion of the alcoholysis is left un-alcoholyzed. The degree of alcoholysis is therefore expressed in terms of the degree of alcoholysis, i.e.the degree of alcoholysis is the percentage of the total number of units of the polyvinyl alcohol molecule based on the number of vinyl alcohol units, the remainder of the units not subjected to alcoholysis being vinyl acetate. The alcoholysis degree is closely related to physical properties thereof, such as water solubility, hydrophilicity, softening temperature, mechanical strength, etc., and when the alcoholysis degree is matched with other substances, such as a polyhydroxy substance, hydrogen bonds can be formed between the two substances, and the hydrogen bonds are different in degree according to the mixing ratio, thereby affecting the physical properties. Therefore, the present inventors have intensively studied and tested to obtain a substrate composition for preparing a strongly hydrophilic microneedle.

The polymerization degree and the alcoholysis degree are represented by four digits, the first two digits represent the polymerization degree, the last two digits represent the alcoholysis degree, and for example, 3588 polyvinyl alcohol has a polymerization degree of 3500 units and an alcoholysis degree of 88%. In the following description, unless otherwise specified, four-digit numbers are used to designate polyvinyl alcohol having the degree of polymerization and the degree of alcoholysis. Corresponding polyvinyl alcohol can be obtained from the market, and when the polyvinyl alcohol with special specification is needed for testing the performance of the invention, the polyvinyl alcohol is synthesized and characterized according to the method of the prior art and then used (the reference document: the control of alcoholysis degree of polyvinyl alcohol production, Qiuchangrong, chemical engineering and equipment, the ninth stage P66-70 of 2009).

The physical properties of the obtained substrate mainly depend on the polymerization degree and alcoholysis degree of the polyvinyl alcohol and the proportion of the small-molecule polyhydroxy compound, and to a lesser extent depend on the type of the small-molecule polyhydroxy compound, and the influence degree of the factors can be obtained from experiments.

Preferably, the polyvinyl alcohol has a polymerization degree of 300 to 3500, and a alcoholysis degree of 88 to 100%. By convention, the degree of alcoholysis of fully alcoholyzed polyvinyl alcohols is denoted as XX99, not XX 100.

Preferably, the polymerization degree of the polyvinyl alcohol is 300 to 2600.

Preferably, the degree of alcoholysis is 88% or more.

Preferably, the hydroxyl group ratio is 0.15:1 to 1: 1.

The micromolecular polyhydroxy compound is selected from one or more of glycerol, erythritol, threitol, xylitol, arabitol, ribitol, sorbitol (sorbitol), mannitol (mannitol), galactitol, iditol, heptatol, ribose, xylose and glucose.

Preferably, the small molecule polyol is selected from one or more of glycerol, erythritol, xylitol, sorbitol and mannitol.

The polyvinyl alcohol molecule contains a large number of hydroxyl groups (the amount of the hydroxyl groups is characterized by alcoholysis degree), and can form tight intramolecular or intermolecular hydrogen bonds, so that the melting temperature of the polyvinyl alcohol molecule is higher than the decomposition temperature, and the polyvinyl alcohol molecule has almost no thermoplasticity; after the micromolecular polyhydroxy compound is mixed in the polyvinyl alcohol, hydrogen bonds in the polyvinyl alcohol molecules or among the polyvinyl alcohol molecules are weakened by partial release, and the thermoplasticity is increased; after the micromolecule polyhydroxy compound is heated and converted into liquid, the melt flowability of the material is increased; namely, after the addition of the small-molecule polyhydroxy compound, the two functions are beneficial to the thermoplastic molding of the mixed material. Therefore, the thermoplasticity of the composition can be controlled by adjusting the addition amount of the small-molecule polyol.

The addition can be estimated from the molecular level: each small molecule hydroxyl group can react with one polyvinyl alcohol hydroxyl group, and the proportion relation of the two hydroxyl groups can be converted into a weight relation. The molecular weight of the vinyl alcohol units is 44 and the molecular weight of the non-alcoholyzed vinyl acetate units is 86, and, depending on the degree of alcoholysis, the average molecular weight of the polyvinyl alcohol units, vinyl alcohol molecular weight x degree of alcoholysis + vinyl acetate molecular weight x (1-degree of alcoholysis), for example, the molecular weight of the units with 80% degree of alcoholysis: 44 × 80% +86 × 20% + 35.2+17.2 ═ 52.4; the 100% alcoholysis degree is as follows: 44 × 100% ═ 44; one hydroxyl group per average molecular weight unit. The molecular weight of the small molecule polyol is divided by the number of hydroxyl groups contained to give the molecular weight of each hydroxyl-containing unit, e.g., glycerol 30.67, mannitol 30.3.

Based on the above estimation, taking the hydroxyl group ratio of the small molecule polyol to the polyvinyl alcohol to be 0.1:1, it can be estimated that, for example, the weight ratio of glycerin to polyvinyl alcohol having an alcoholysis degree of 80% is 0.059: 1; when the ratio of hydroxyl groups is 1.3:1, the weight ratio of mannitol to polyvinyl alcohol having a degree of alcoholysis of 100% is 0.9: 1. According to the estimation, the inventor tests polyvinyl alcohol compositions mixed with different amounts of small molecular polyhydroxy compounds, and finds that the ratio of hydroxyl groups of the small molecular polyhydroxy compounds to the polyvinyl alcohol is better when the ratio of the hydroxyl groups is 0.1: 1-1.3: 1, the thermoplasticity and toughness of the polyvinyl alcohol are poorer when the ratio of the hydroxyl groups is less than 0.1:1, the change is started when the ratio of the hydroxyl groups is more than 0.1:1, the material begins to show the thermoplasticity and toughness which can be processed into the micro-needle by a simple process, and the material gradually loses the required toughness when the ratio of the hydroxyl groups is more than 1.3: 1. According to experimental data, the performance is better when the hydroxyl ratio is 0.15: 1-1: 1.

According to the above estimation, the hydroxyl ratio is 0.1:1 to 1.3:1, corresponding to a weight ratio of about 0.05:1 to 0.9:1 for the preferred combination of the invention with the addition of, for example, mannitol, and so on.

The microneedle substrate composition can be in various forms for convenient use, for example, the microneedle substrate composition can be packaged respectively, can be weighed and mixed for use according to the proportion in use, can also be premixed according to the proportion to form blended powder for use, can be used as a hot-press molding material, and can be selected according to a preparation method of microneedles.

Therefore, the invention further provides a strong hydrophilic blank microneedle, which is characterized in that a microneedle substrate is the microneedle substrate composition, namely the blank microneedle is mainly composed of polyvinyl alcohol and micromolecular polyhydroxy compounds, wherein the ratio of hydroxyl groups of the micromolecular polyhydroxy compounds to the polyvinyl alcohol is 0.1: 1-1.3: 1, the polymerization degree of the polyvinyl alcohol is 300-3500, and the alcoholysis degree is more than 80%.

Preferably, the polymerization degree of the polyvinyl alcohol is 300 to 2600.

Preferably, the degree of alcoholysis is 88% or more.

Preferably, the hydroxyl group ratio is 0.15:1 to 1: 1.

Further, the invention provides a preparation method of the blank microneedle with strong hydrophilicity, which comprises the steps of blending the polyvinyl alcohol powder and the micromolecular polyhydroxy compound powder at room temperature according to the hydroxyl ratio (converted into weight ratio) to form blended powder, hot-pressing the blended powder into a molding material, and hot-pressing the molding material into a mold to form the blank microneedle; or the blended powder is subjected to hot mixing and melting extrusion by a blending machine at a certain temperature to form a section material, and the section material is hot-pressed into a mould to form a blank microneedle (the details are shown in figure 6 and figure 7: 700 as a blank microneedle whole, and 701 as a blank microneedle body).

In an optimized embodiment of the invention, the die is a flat plate with the thickness of 0.2-3 mm, and is provided with one or more groups of micropore arrays, wherein micropores are through holes; the flat plate is made of metal such as aluminum copper, or polymer material, and the flat plate made of these materials can be obtained from the market, such as polytetrafluoroethylene, polytrifluoroethylene, polyoxymethylene, polyether polyketone, polyimide, and materials obtained by modifying these polymer materials.

When such a mold is used to prepare the substrate composition microneedles, appropriate pressure and temperature are required to obtain good blank microneedles. Under a certain pressure, the molding temperature is generally positively correlated with the polymerization degree and alcoholysis degree of polyvinyl alcohol, the molecular weight and melting point of the small-molecule polyhydroxy compound, and is generally negatively correlated with the proportion of the small-molecule polyhydroxy compound.

Mode of using the mold: the blended powder or the profile can be added above a mould and heated to form a molten flow with fluidity, and the pressure can be applied from the upper part of the material on the mould to the lower part, or vacuum pressure can be pumped from the lower part of the mould, or the pressure is applied from the upper part and simultaneously the vacuum pumping is carried out from the lower part, so that the molten flow enters the micropores of the mould. A more preferred method of preparation is by use of a specialized microneedle preparation apparatus, typically one that includes an upper pressurization and lower depressurization system. (details are shown in the attached figure 1 and the content of example 2; references: ZL 201822070608.8, ZL 201822068011, X, ZL 201822070605.4, ZL 201822071901.6, ZL 201822070604. X)

The temperature range, such as the example listed in the table of fig. 23, can be experimentally obtained by thermally extruding a material of a substrate composition of different compositions under a certain pressure to produce a minimum molding temperature for a blank microneedle, and as a lower temperature limit of the suitable temperature range, an upper temperature limit thereof should be lower than the decomposition temperature of the polyvinyl alcohol used; within the range of the lower limit and the upper limit of the temperature, the blank microneedle can be prepared by only adjusting the pressure and shortening the heating time of the material, and is not particularly limited; the contact with oxygen is reduced, and the decomposition of polyvinyl alcohol is prevented. For reference, the literature reports that polyvinyl alcohol with an alcoholysis level of 88% has a decomposition temperature of around 240 ℃; 99% of the samples were about 245 ℃ (see "high decomposition temperature PVA preparation and performance research", Master academic thesis of Kingson, Zhejiang industrial university, leading teacher's high-definition, Fancui, institute of Material science and engineering, 1 month in 2019).

The base material has good thermoplasticity and toughness, is beneficial to process stress, and the surface of the prepared microneedle has strong hydrophilic polarity, is beneficial to firm adhesion of the drug and increase of drug loading.

By utilizing the blank microneedle, the invention also provides a drug-loaded microneedle which is formed by contacting, attaching and drying a solution containing a drug with the blank microneedle. As long as the medicine can be adsorbed on the strong hydrophilic surface, the prepared blank microneedle can be contacted with the prepared medicine-containing solution to adsorb and load, and then the product is obtained. Therefore, the microneedle can be widely applied to drug delivery as required, and particularly, the blank microneedle can be used for conveniently carrying drugs which cannot tolerate higher temperature; the drug-loaded micro-needle can form drug enrichment on the cortex of the drug-loading part, which is beneficial to the treatment of related diseases, and the drugs taken orally or injected need to pass through a digestive absorption system and/or be distributed in the whole body for blood circulation, so the drug-loading efficiency of local skin is not high, and the drugs are smeared outside the skin, and are not sufficiently separated and permeated by the epidermis. For example, finasteride is known to correct alopecia and promote hair growth, preferably a small dose is used and concentrated on the superficial layer of the scalp, and the micro-needle administration can realize the enrichment of the small dose on the scalp and reduce the harmful effect on the whole body, and has obvious advantages. For example, insulin can be administered by using a microneedle, and the microneedle can be applied to the skin without injection, thereby reducing pain. The microneedle can be easily made into a combined microneedle with several drugs respectively carried on needle points at different positions to reduce administration times, for example, an insulin microneedle is made into a circular big half part, an exenatide microneedle is made into a circular small half part, the circular back surfaces of the two parts are adhered to another wafer to form the combined microneedle (see the attached drawings, 20: 20 is a full needle, 201 is a drug carried by the big half circle of the microneedle, 202 is a drug carried by the small half circle of the microneedle, and 203 is a back plate for adhesion). The micro-needles loaded with different drugs are mutually isolated and are also spliced together, so that the use is convenient.

The blank microneedle can carry a plurality of kinds of medicaments, such as insulin medicaments, exenatide medicaments, human growth hormone, finasteride, calcitonin medicaments, protein medicaments, peptide medicaments and the like, at the tip of the needle tip; the basic principles for selecting a drug are proper dosage, other modes of administration less convenient than microneedles, the need to provide a concentrated concentration of drug in the local skin, instability of the drug in other formulation forms, and the like. The microneedle preparation technology has two outstanding pharmaceutical advantages, the drug is not subjected to high temperature and has larger drug loading in a wrapping mode, and the common advantage of the microneedle preparation is that the selected drug can realize one or more of the advantages, so that the microneedle preparation is a proper choice. The proper selection can be a single medicine or a compound compatibility of two or more medicines which are mixed and contacted. The medicine compound compatibility is that the quality is not affected and the medicine effect can be exerted after several medicines are mixed and contacted; preferably, it should be approved by medical regulations in other forms of formulation, such as "norham" which is an injection of short-acting insulin combined with intermediate-acting insulin. In the case of drugs whose quality is affected by direct contact, if co-administration is required, the combination of microneedles is an ideal arrangement. Therefore, there is no need to make any special restrictions on the drug species, and the intellectual property protection of the microneedle preparation of the appropriate drug species is not lost because no special restrictions are made.

The drug-loaded microneedle is formed by contacting, attaching and drying a blank microneedle and a drug-containing solution, namely the preparation of the blank microneedle and the drug-loading process of the microneedle are carried out in a subsection mode. The blank microneedle can be conveniently produced in a large scale, and the convenience is shown in the following steps: firstly, the preparation of only a blank microneedle involves high temperature, the conditions of subsequent drug loading are very mild, and the quality of the drug is ensured; secondly, the medicines are not mixed with the microneedle material into a whole, the properties of the microneedle material are not affected, and the factors such as the toughness, the brittleness and the like of the blank microneedle material are easy to regulate and control; and thirdly, the adjustment of the drug release behavior can be conveniently realized only by adjusting auxiliary materials in the liquid medicine. The mixed drug-loaded microneedle takes the properties of materials and the release behavior of the drug into consideration, and the regulation difficulty and related factors are increased; fourthly, the liquid medicine is only wrapped on the surface of the needle tip to form a liquid film with large surface area and small thickness, the drying time is short, the temperature is low, and the process amplification is facilitated.

The drug-containing solution can use common related pharmaceutical excipients to help the drug loading and better exert the drug effect as long as the drug loading is facilitated, and the drug effect exertion is not influenced and no adverse effect is generated on human bodies.

Further, the method for carrying the drug by using the prepared blank microneedle is characterized in that the water-soluble drug is directly prepared into aqueous solution for carrying the drug, and a proper amount of adhesive is added for better carrying the drug; if the adhesion force between the solid film layer formed by drying the water-soluble medicament and the microneedle base material is satisfactory, the solid film layer can be firmly attached to the surface of the needle point without shrinking to generate cracks and generating shearing force on the combination interface of the medicament and the microneedle, so that an adhesive is not added or slightly added generally; uniformly suspending the water-insoluble drug in water or dissolving/suspending the drug in a non-aqueous polar solvent for drug loading, and adding a proper amount of adhesive for better drug loading; the non-aqueous polar solvents are typically methanol, ethanol and isopropanol, with ethanol being most commonly used in view of polarity, solubility and biosafety. In specific use occasions, for example, quick release is needed, auxiliary materials with strong water solubility and proper viscosity can be used, the proper viscosity refers to that the medicine can be adhered on the microneedle and can be quickly dissolved to promote the medicine to quickly contact body fluid, and the auxiliary materials which can be usually selected are low-component povidone or polyethylene glycol; if slow and long-acting release is needed, povidone or polyethylene glycol with different molecular weights can be generally used for comparison and selection, the hydrophilicity of the povidone or polyethylene glycol is kept unchanged along with the increase of the molecular weight, but the viscosity is increased, after the povidone or polyethylene glycol contacts body fluid, the swelling process and the process of dissolving the povidone or polyethylene glycol into the body fluid after swelling are both slowed down, and the release of the medicine is also slowed down; the dosage of the auxiliary materials is closely related to the drug release behavior, and the dosage of the auxiliary materials can be adjusted on the premise of ensuring firm attachment, and the drug release can also be adjusted. If an adjuvant cannot satisfy both viscosity and water solubility requirements, related substances can be added to change viscosity or water solubility. In the aspect of pharmacy, the method for changing the drug release behavior and the available auxiliary materials are more, and the comparison and selection of the drug release behavior can be carried out through experiments, so that the balance of factors such as the drug, the auxiliary materials, the adhesion, the drug release and the like is achieved. In specific application occasions, for example, a quick release and a long-acting duration are needed, two medicaments of quick release and long-acting duration can be mixed and integrated to form a microneedle (for example, an injection 'nordherin' formed by mixing short-acting insulin and medium-acting insulin together), or the combined microneedle is formed. Therefore, the selection of the auxiliary materials and the proportion of the dosage on the microneedle which are favorable for drug loading and release belong to the invention concept and the protection scope of the invention.

The hydrophilicity and hydrophobicity of the drug can be improved by methods such as salt formation, base formation, acid or base exchange, pH adjustment of the drug solution, etc., as long as the drug effect and the biologically acceptable form are facilitated, for example, polypeptide protein drugs, whose hydrophilicity and hydrophobicity vary greatly around the isoelectric point, can be prepared and used as needed.

In a preferred set of embodiments of the invention, the aqueous solution of the water-soluble drug is a sodium chloride solution (30% w/w), wherein sodium chloride is used as the simulated water-soluble drug; the adhesive is povidone k30 (or polyethylene glycol 600) and is prepared into 3-15% aqueous solution; the water-insoluble simulated medicine is calcium carbonate powder (200 meshes), and the concentration of the adhesive solution is selected according to the proper specific gravity, such as 8% -13% of povidone k30, and after shaking, mixing and standing for 2 hours, the calcium carbonate powder is still uniformly suspended in the adhesive solution and does not settle and float. The two solutions are placed in an open manner for 10 minutes at the temperature of 25 ℃ and the relative humidity of 85 percent, the volatilization weight loss is less than 1 percent, and the requirement of medicine carrying precision is met.

In one group of embodiments of the invention, povidone k30 aqueous solution (10% w/w) is used, insulin powder and povidone aqueous solution are mixed to form solution (20:80w/w) containing insulin, the solution is contacted with a blank microneedle to load an insulin microneedle, and the insulin microneedle is attached to the ear of a diabetes model pig, so that the insulin microneedle has a remarkable blood sugar reduction effect.

In one group of embodiments of the invention, the exenatide powder and the povidone solution are mixed into a solution (2:98w/w) containing exenatide by using a povidone k30 solution (10% w/w), the solution is contacted with a blank microneedle to load an exenatide microneedle, and the exenatide microneedle is attached to the ear of a pig with a diabetes model, so that the exenatide microneedle has a remarkable blood sugar reduction effect.

In short, when a solution containing a drug is prepared, the amount of the drug to be loaded and the adsorption strength can be confirmed by experiments, and the drug can be adjusted by adding an additive that contributes to the loading and increases or decreases the adsorption force. The additives may be substances that adjust pH, viscosity, ionic strength, film-forming properties, and the like.

The preparation of the microneedle can be realized by hot-pressing the involved blended powder into a molding material (wafer) and then hot-pressing into the microneedle, namely adding the blended powder into a special wafer manufacturing device, putting the device in a hot environment, heating to a hot-pressing temperature (such as 0599/mannitol powder (1:0.65w/w) and 200 ℃), carrying out hot pressing for a certain time, cooling to room temperature, and taking out the manufactured wafer. And placing the wafer into a blank microneedle manufacturing device, placing the device in a hot environment, heating to a hot pressing temperature (such as 0599/mannitol powder (1:0.65w/w) and 200 ℃), carrying out hot pressing for a certain time, cooling to room temperature, taking out the mold plate, and separating the microneedle from the mold to obtain the blank microneedle. Preferably, the material thermally extruded by the apparatus is processed into a material (wafer), the wafer is placed into a special blank microneedle manufacturing device, the device is placed in a hot environment, the device is heated to the hot pressing temperature for a plurality of minutes, then hot pressing is carried out for a certain time, the temperature is cooled to the room temperature, the mold plate is taken out, and the microneedle is separated from the mold to obtain the microneedle. Further, in order to reduce the heating time of the wafer, the special device can be preheated to the pressing temperature, the prefabricated wafer is placed on the mold preheated to the temperature, the temperature is kept for several minutes, the wafer reaches the hot pressing temperature, the wafer is pressurized for several minutes, the mold plate is taken out when the wafer is hot, the wafer is cooled, and the microneedle is separated from the mold to obtain the microneedle. (details are shown in the attached figure 1 and the content of example 2; references: ZL 201822070608.8, ZL 201822068011, X, ZL 201822070605.4, ZL 201822071901.6, ZL 201822070604. X)

The compositions of the substrate and the blank micro-needle can be identified by a spectroscopic method, for example, a characteristic peak of a nuclear magnetic resonance spectrum and the like is used for representing a composition formed by polyvinyl alcohol and a small molecular polyhydroxy compound, and qualitative detection can be carried out by the specific color reaction of the polyvinyl alcohol and the small molecular polyhydroxy compound and divalent copper ions. Its properties can be evaluated by testing its hydrophilicity, adsorptivity, resistance to mechanical peeling, etc. For example, preparing a test solution containing sodium chloride, povidone k30 and water, preparing a hydrophobic polystyrene wafer, a hydrophilic ethylene-vinyl alcohol copolymer wafer and a strongly hydrophilic polyvinyl alcohol/small-molecule polyol wafer of the invention, respectively dripping the test solution on the wafers, standing and drying, and observing the adhesion condition. The base material wafer of the invention firmly adsorbs the solid spots of the tested solution, can not be peeled off by a pin, and only leaves scratches on the surface; the air is blown by an electric blower to prevent separation. Spots on other control discs were easily peeled off and blown off.

For example, the blank microneedles of the present invention may be used to detect the presence of polyvinyl alcohol and small molecule polyols characterized therein using color development and hydrogen proton nuclear magnetism after the microneedles are crushed and pretreated.

The prepared microneedle carrying the drug can be identified by the same method as the blank microneedle, and if the carried drug has influence on the identification, the needle tip part of the microneedle carrying the drug can be cut off and then identified by the same method.

The blank microneedle manufacturing method also has the process items of convenience for operation such as separating the microneedle from the mould plate and removing residual materials in the micropores of the mould. When the ratio of the micromolecular polyhydroxy substance to the polyvinyl alcohol is less than 0.15:1, the brittleness of the base material is larger, so that the dissociation difficulty is increased, the needle breakage phenomenon often occurs, and after the ratio is more than 0.15:1, the micromolecular polyhydroxy substance and the polyvinyl alcohol can be easily dissociated, and the needle number is kept complete; at the sharp end of the micro-hole of the mold after the micro-needle dissociation, a trace amount of material sometimes remains to be removed, otherwise blockage may be formed, so that the mold fails, the best method for removing the residue is boiling in water for dissolution, however, when the polymerization degree of the polyvinyl alcohol is more than 2600, the boiling time is obviously too long, and after the polymerization degree is more than 2600, the material can be fully swelled, but the viscosity is too high, so that the time for dissolving the material into the water phase is too long, and the amplification of a mass production process is not facilitated. In addition, the solubility of the polyvinyl alcohol with the polymerization degree of 78-85% in cold water is the maximum, so that after the needle body with the polymerization degree enters the skin hole to absorb body fluid, the needle body with the polymerization degree is subjected to transition swelling and disordered deformation, so that the drug release behavior is greatly changed, and the phenomenon is not observed when the polyvinyl alcohol with the polymerization degree of more than 88%.

Example 1: microneedle composition substrate forming temperature range testing and control

Microneedle composition substrate formulations according to the present invention: the ratio of the small molecule polyol to the polyvinyl alcohol was blended to obtain a blended powder, which was processed on the microneedle preparation apparatus of example 2 under a pressure range (28-32 kg/cm)²) The lower temperature for better handleability was obtained by adjusting the temperature for better preformed wafers and/or microneedle formation and the results are collated in the table of FIG. 23, which shows the temperature at 28-32kg/cm²Under the pressure condition, the molding temperatures of the preformed wafers and/or the microneedles of different hot extrusion materials are different, and the mixture ratio is weight ratio, and the unit is w/w.

The thermoplastic temperature of polyvinyl alcohol is well below its decomposition temperature after the addition of small molecular weight polyols such as mannitol, sorbitol and erythritol. The literature reports that the decomposition temperature of polyvinyl alcohol with 88% alcoholysis degree is about 240 ℃ and 99% thereof is about 245 ℃ (see "preparation and performance research of PVA with high decomposition temperature", Master academic thesis of Kingson, Zhejiang industry university, leading teacher's strong chimerism, Fanshan, academy of materials science and engineering, and 2019 for 1 month.

Example 2: device and process method for preparing prefabricated wafer, blank microneedle and other material round plate for test

FIG. 1 is a schematic view showing an example of a microneedle preparation apparatus used in the present invention. The test blank microneedles and test sample wafers of the present invention were all completed on the device.

As shown in fig. 1, the special microneedle preparation device comprises an upper compacting plate 1, a mould plate 2, an isolating layer 3 and an air extracting plate 4 from top to bottom in sequence, the isolating layer 3 is made of a breathable liquid-tight material, a micropore area 21 corresponding to the needle-shaped object of the microneedle is arranged on the mould plate 2, the micropores are through holes, a cavity 41 is arranged in the air exhaust plate 4, air exhaust micropores 42 communicated with the cavity 41 are arranged on the air exhaust plate 4 corresponding to the position of the micropore area 21, an air exhaust pipe 43 communicated with the cavity is arranged outside the air exhaust plate 4, an auxiliary pressing device 11 which is manually or automatically pressed upwards and downwards is arranged above the upper pressing plate 1 (the auxiliary pressing device 11 is not shown in detail in the figure), so as to conveniently press downwards and loosen the mould upwards, the upper pressing plate 1 is also provided with a through hole 12, the through holes 12 are positioned in accordance with the micro holes 21 of the die plate for pressurizing the material and limiting the sheet diameter. The through hole 12 on the upper pressure plate 1 is also consistent with the pressure rod 8 on another auxiliary pressure device 7 (the auxiliary pressure device 7 is not shown in detail in the figure) above, and the upper pressure device 7 is manually or electrically lifted or pressed down through the through hole 12 to complete the pressing and the dissociation of the micro-needle. The pressure rod 8 exerts pressure on the melt flow base material through a spring 9 sleeved on the pressure rod, and the spring 9 is used for controlling the downward pressure within a certain range. An isolation layer 5 is arranged between the pressure rod 8 and the microneedle material 6 to prevent mutual adhesion and facilitate separation. The pressure rod 8, the through hole 12 and the auxiliary pressure device 7 are in a sliding tight fit relationship so as to ensure the positioning, the sliding and the non-overflow of materials.

The operation process is as follows: descending and ascending a compression plate 1 and compressing a mould plate 2; lifting the pressure rod 8 to leave the through hole 12, placing the molding material on the mold micropore area 21 through the through hole 12, descending the pressure rod 8, and pressing the molding material into the microneedle; the upper lifting pressure rod 8 releases the pressure of the spring 9 on the material; lifting the pressing plate 1, releasing the pressing on the mould plate 2, and lifting the pressure rod 8 to separate the mould plate from the microneedle; drawing out the mold plate 2, cooling and dissociating the microneedles 6 on the mold plate; all the lifting and lowering is realized by the auxiliary pressing device 11 and the auxiliary pressure device 7. When the wafer is prepared, the mold plate 2 may be replaced with a flat plate of the same material. The spring 9 is a commercially available rectangular spring with a green mold and a pressure of 32kg/cm²The pressure is reduced to 28kg/cm after repeated use²The pressure is set to be 28-32kg/cm². Hereinafter, unless otherwise specified, all of such springs are referred to. Similarly, it can be seen that the relationship between pressure and temperature,the amount of the solvent to be used is not particularly limited, and may be varied within a certain range.

The process of manufacturing the microneedle by using the device is simple (see the flow in fig. 3 and the flow in fig. 4), and the operation process is as described above: placing a pre-prepared molding material (a wafer formed by hot pressing blended powder or a wafer or a granular material extruded by a hot blending machine) in a device, heating the whole device to a hot pressing temperature (the temperature is determined according to a base material and the embodiment 1, the temperature is generally between 180 and 225 ℃), preserving heat (10 minutes) to enable the temperature of the device to be uniform, starting an air exhaust system 4 and a pressure system 7 to enable the melted material to be counted into micropores, manufacturing the microneedle, taking out the whole device and cooling to obtain a blank microneedle. The photo of the blank microneedle is shown in fig. 6, and it can be seen that the blank microneedle has smooth and burr-free surface and regular shape and uniform size. The structure of the blank microneedle is shown in fig. 7, 700 is the whole blank microneedle, and 701 is the body of the blank microneedle.

Preferably, the operation process for preparing the microneedle by using the device is as follows (see the flow chart in the attached figure 5): the device is always placed in a hot-pressing temperature environment (an oven; a temperature zone is between 180 ℃ and 220 ℃ according to the property of a base material), and after the temperature reaches 10 minutes, the heat inside the device is balanced; placing the substrate wafer into the container, keeping the temperature for 2 minutes, heating the wafer to the temperature, and exhausting and pressing the wafer for 1 minute to prepare the microneedle; and drawing out the mold plate with the microneedles, and cooling to obtain blank microneedles. According to the embodiment, 45-55 minutes of heating and cooling of the whole device is saved, the wafer is heated for 2 minutes only and is heated for 1 minute for pressure application, the heat capacity of the withdrawn die plate and the microneedle on the die plate is small, the temperature reduction speed is high, the heating time of the base material is greatly shortened, and the quality guarantee and the process amplification of the microneedle are facilitated.

The simple operation process of the wafer manufacturing is very similar to the blank microneedle process, and the die plate is replaced by the base plate made of the same material to obtain the wafer.

Example 3: adhesion test of substrates

Three experimental discs were prepared: (1) hydrophobic polystyrene wafer (powder of Dongguan Xingwang plastic raw material Co., Ltd., molecular weight is not marked, but adhesion judgment is not hindered); (2) hydrophilic ethylene-vinyl alcohol copolymer disks (three powders of kuraray, japan, E105B (44mol/56mol), F104B (32mol/68mol), L171B (27mol/73mol), no molecular weight is disclosed, but adhesion judgment is not hindered); (3) the polyvinyl alcohol/small polyol substrate wafer of the present invention, which is strongly hydrophilic (polyvinyl alcohol powder from Shanghai Yinjiao developments, each small polyol being available from several vendors), is shown in the table in FIG. 24 for details.

Preparing a test solution: the weight ratio of the sodium chloride, the povidone k30 and the water is 20/8/72. The solution is placed in an open environment with the temperature of 25 ℃ and the relative humidity of 85 percent for 10 minutes, the volatilization weight is reduced by less than 1 percent, and the requirement of the precision of medicine carrying is met.

A small amount (about 0.1mg) of test solution is respectively dipped on the surfaces of the wafers, the wafers with liquid medicine spots dipped on the surfaces are placed in a dryer at room temperature for 24 hours, spot wafers are obtained, the following experimental observation is carried out, the experimental result of the adhesion force of the base material to the spots formed by the sodium chloride/povidone solution is shown in a table in figure 25, and the result shows that the base material of the invention all shows good adsorption fastness.

Manual needle tip lift-off experiment: under a high magnification magnifier (30 times), the spot is touched by a metal needle point, and the change condition of the spot is observed.

Blow-off experiment with electric hair dryer: the spot face is stuck on the wafer, the electric hair drier is used for cold blowing for 3 minutes, and a high power magnifying glass (30 times) is used for observing whether the spot is blown away.

One meter high free fall experiment: after each wafer freely falls through a one-meter long glass tube, whether the spots fall off is observed through a high power magnifier (30 times).

Example 4: after the blended powder base material is hot-pressed into a wafer, the wafer is hot-pressed into a microneedle

According to the method described in the above example 2, using the special manufacturing apparatus shown in FIG. 1, the operation is performed according to the flow of FIG. 3, 0.65g of blended powder (1:0.65w/w) of polyvinyl alcohol 0599 and mannitol powder is added into the special manufacturing apparatus, the apparatus is placed in a hot environment, heated to a hot pressing temperature (200 ℃), pressurized and kept warm for 27 minutes, and then the apparatus is cooled to room temperature to obtain a wafer; and then placing the wafer into a device for manufacturing the microneedle, heating to the hot pressing temperature (200 ℃), pressurizing, preserving heat for 27 minutes, and cooling to the room temperature to obtain the blank microneedle.

Example 5: after the hot blending extrusion material is hot-pressed into a circular sheet, the circular sheet is hot-pressed into a microneedle

According to the method described in the above example 2, using the special manufacturing apparatus shown in FIG. 1, the operation is performed according to the flow shown in FIG. 4, 0.65g of mechanically hot-extruded granules of the blended powder (1:0.65w/w) of polyvinyl alcohol 0599 and mannitol powder are added into the special manufacturing apparatus, the apparatus is placed in a hot environment, heated to a hot pressing temperature (200 ℃), pressurized and kept warm for 27 minutes, and then the apparatus is cooled to room temperature to obtain a wafer; and then placing the wafer into a device for manufacturing the microneedle, heating to a hot pressing temperature (200 ℃), pressurizing, preserving heat for 27 minutes, and cooling the device to room temperature to obtain a blank microneedle.

Example 6: making wafer and blank micro-needle according to method for shortening material heating time

According to the method for shortening the heating time of the material described in the embodiment 2, the special manufacturing device shown in the attached drawing 1 is used, the operation is carried out according to the flow shown in the attached drawing 5, the special manufacturing device is preheated to the hot pressing temperature (200 ℃) and the overall temperature of the device is balanced for 10 minutes, 0.65g of polyvinyl alcohol 0599 and mannitol powder blend (1:0.65) or 0.65g of mechanically hot extruded granular material with the same proportion is added into the special manufacturing device, after the material is heated for 2 minutes continuously (the material is heated), the hot pressing is carried out for 1 minute, the pressure is relieved, and the base plate is extracted and cooled to obtain a wafer; preheating the special manufacturing device to the hot pressing temperature (200 ℃), after the whole temperature of the device is balanced for 10 minutes, putting the wafer into the device, continuously heating for 2 minutes (making the wafer reach the temperature), carrying out hot pressing for 1 minute, relieving the pressure, drawing out the die plate and cooling to obtain the blank microneedle.

Example 7: microneedle drug loading test, observation and analysis of liquid medicine adhesion form and adhesion fastness test

The weight ratio of sodium chloride, povidone k30 and water is 20: 8: the 72 solution was used as a blank microneedle drug loading test solution. After the blank microneedle carries the medicine, the image that the medicine firmly adsorbs under the high magnification magnifying glass (30 times) at needle point position is as shown in fig. 8, and the structure of medicine carrying microneedle is as shown in fig. 9, and in fig. 9, 900 is the medicine carrying microneedle wholly, and 901 is medicine carrying microneedle body, and 902 is the medicine carrying part of medicine carrying microneedle body point portion.

Blank microneedle adsorption test solution test: a test solution having a limited solution height was obtained by providing a square metallic aluminum block (5 cm. times.5 cm. times.2 cm) on the surface thereof with shallow circular grooves 30mm in diameter and 0.1mm, 0.15mm and 0.2mm in depth, respectively, adding a test solution to the grooves, and scraping off the overflowing liquid by translation with a squeegee. Precisely weighing (1/100000 balance) blank microneedles made of various materials in proportion, standing in a circular groove with the needle point vertically downward for 3 seconds, taking out the microneedles, precisely weighing, and calculating to obtain net weight gain by weight loss; observing the form of the liquid medicine drop hung on the needle point by a high power magnifying glass (30 times); after the drug-loaded microneedle is hung in a dryer (room temperature for 24 hours), the drug-loaded microneedle freely falls down by one meter, and the falling-off condition of the drug at the needle point is observed by a high-power magnifying glass (30 times). The results are shown in the tables in fig. 26 to 28.

FIG. 26 shows the amount of test solution adsorbed by the microneedles in mg; FIG. 27 is a view showing a state where a drop of the drug is caught on a needle tip under observation with a high magnification magnifier (30 times), wherein a indicates a pearl-like tip, b indicates a spindle-like tip, and c indicates a pearl tip, and the three forms are shown in FIG. 10;

when the micro-needle leaves the liquid level, the liquid drop form hanging on the tip of the needle is observed by a 30-time magnifying glass, and the state that the liquid medicine wrapping the needle tip is presented by hanging the liquid medicine on the blank micro-needle with different substrates can be seen, as shown in the attached figure 10: when the liquid hanging amount is small enough, the hanging liquid on the materials is wrapped on the needle tip in a drop shape, and the drop shape is not exposed at the tip in a state of a and 1001 shown in the attached drawing 10; along with the increase of the liquid suspension amount, the liquid on the needle point of the microneedle with the strong hydrophilic base material is spread into a spindle shape along the axial direction and wraps the needle point, as shown in b of the attached drawing 10, the 1002 state is that the spindle shape does not expose the tip, which shows that the affinity between solid and liquid phases is greater than the surface contraction force of the liquid phase; the liquid on the needle tip of the comparative base material, i.e., the low-polarity or non-polar material, moves upward in the form of a bead to expose the needle tip, as shown in c of FIG. 10, and the state 1003, i.e., the bead is exposed, indicating that the affinity between the solid and liquid is smaller than the liquid surface contraction force.

It can be reasonably presumed that when the microneedle is inserted, the microneedle made of the strong hydrophilic base material of the present invention can bring the strongly attached drug into the skin hole, while the weakly attached drug of the control microneedle can be partially pushed out of the skin, and the specific drug effect performance is also demonstrated in the subsequent drug effect example test.

Because the depth of the microneedle entering the skin is limited, generally, only the drug wrapped in the needle point part within 0.3mm can stably generate the drug effect, and the drug at the rear part is gradually far away from the most easily absorbed section, so that the b-shaped spindle-shaped liquid medicine wrapping without exposing the tip is in a better state.

Fig. 28 is a table showing how a microneedle which adsorbs a drug falls off at a height of one meter, and then the microneedle is observed with a high magnification magnifier (30 times), where a in fig. 28 shows that the microneedle does not fall off, and b shows that the microneedle falls off.

Example 8: impact toughness test of microneedle substrate

A wafer having a diameter of 1.9cm, a thickness of 1mm, a thickness of 1.5mm and a thickness of 2mm was prepared as a test piece from the substrate of the present invention in example 3; povidone (PVP k-30) was formed into disks of the same size as the control.

The test and control wafers were each laid flat on a steel plate in an environment of 17 ℃ and a relative humidity of 46%, and vertically and freely dropped on a wafer needle by using a 15.8g steel cylinder through a glass tube having an inner diameter of 2cm and a length of 55cm or 84cm, and the above was repeated 3 times, and the chipping was shown in a table in FIG. 29.

The reason for selecting povidone discs as the control test article was: 1. can be formed by thermal molding; 2. as the most common substrate for many microneedle cases, the substrate of the present invention has toughness that can substantially withstand the subsequent process stress, and as the experimental results shown in the above table, the substrate of the present invention has better toughness and is more suitable for microneedle processing.

Example 9: blank microneedle drug loading test

The blank micro-needle prepared according to the invention carries the drug, generally, only the water-soluble drug is directly prepared into the water solution to carry the drug, or a proper amount of adhesive is added to carry the drug, if the solid film layer formed by drying the water-soluble drug has satisfactory adhesion with the micro-needle substrate, does not shrink to generate cracks, does not generate shearing force on the combination interface of the drug and the micro-needle, and can be firmly attached to the surface of the needle point, therefore, the adhesive is not added or slightly added generally; the water-insoluble drug is uniformly suspended in water or dissolved/suspended in a non-aqueous polar solvent for drug loading, or preferably, a suitable amount of a binder is added for drug loading.

The same test was carried out using the square metallic aluminum block (5 cm. times.5 cm. times.2 cm) of example 7.

In the drug loading experiment of the water-soluble drug, the weight ratio of sodium chloride, povidone k30 and water is 20: 8: 72 solution is used as tested solution, the solution is placed in an open manner for 10 minutes in an environment with the temperature of 25 ℃ and the relative humidity of 85 percent, the volatilization weight is reduced by less than 1 percent, and the requirement of the precision of medicine carrying is met. The drug loading results are shown in the table of fig. 30, which shows the amount of the test solution of the water-soluble material adsorbed by the microneedle in mg.

In the drug loading experiment of the water-insoluble drug, the used test solution is a suspension prepared by mixing 20g of calcium carbonate powder (200 meshes) and 80ml of povidone k30 aqueous solution (11%), uniformly shaking and standing for 2 hours until calcium carbonate powder is settled or floated. The solution is placed in an open manner for 10 minutes at the temperature of 25 ℃ and the relative humidity of 85 percent, the volatilization weight is reduced by less than 1 percent, and the requirement of the precision of medicine carrying is met. The drug loading results are shown in the table of fig. 31, which shows the amount of test solution in mg of the water-insoluble material adsorbed by the microneedles.

Example 10: chromogenic detection of microneedles

The microneedle of the present invention can detect polyvinyl alcohol and polyol specifically present therein by using a color reaction. One specific example of operation is as follows: 0.15 g of polyvinyl alcohol or a small molecular weight polyol is taken and respectively put into 1.8ml of water, heated and dissolved, cooled to room temperature, 10 drops of copper sulfate aqueous solution (17.4% w/w) is added, the pH value of the solution is adjusted to be more than 14 by sodium hydroxide aqueous solution (10% w/w), and at the moment, pink green solid appears in the polyvinyl alcohol solution because pink green chelate of the polyvinyl alcohol and bivalent copper ions is insoluble in water, and the solution of the polyol is changed into brilliant blue because the brilliant blue complex of the polyol and the copper ions is dissolved in the water.

Crushing the hollow microneedle sheet, putting 0.2g of the hollow microneedle sheet into 1.8ml of water, heating to dissolve the hollow microneedle sheet, and cooling to room temperature; 6 drops of aqueous copper sulfate (17.4% w/w) were added and the pH of the solution was adjusted to about 8 with aqueous sodium hydroxide (10% w/w) at which time a pink green solid appeared and the solution portion remained greenish blue or turned substantially colorless to cupric ions. To the separated solution portion, 4 drops of copper sulfate solution were added, followed by addition of sodium hydroxide solution to a pH above 14, at which time the solution became bright blue. The produced pink green solid is a chelate formed by polyvinyl alcohol and copper ions, and the produced solution bright blue is a water-soluble complex formed by polyhydroxy substances and divalent copper ions. Alternatively, 10 drops of copper sulfate solution may be added at a time, followed by addition of sodium hydroxide solution to a pH above 14, while simultaneously producing a pink green solid and a bright blue liquid. If the phenomenon of layering is not obvious, the materials can be centrifugally layered, or 2-4 ml of water is added, shaken up and kept stand until the phenomenon is obvious.

The drug-loaded microneedle can be identified by the same method, and if the carried drug influences the identification, the needle tip part of the drug-loaded microneedle can be cut off and then identified by the same method.

Example 11: hydrogen proton nuclear magnetic spectrum detection of microneedle material

The microneedle of the present invention can be detected by hydrogen proton nuclear magnetic detection, and the specific operations are as follows:

pulverizing empty microneedle, placing 1g in 10ml water, heating to dissolve, and cooling to room temperature to obtain solution 1.

To the other solution 1, 30 drops of 17.4% w/w copper sulfate solution (or copper chloride solution having the same copper ion concentration) was added, the pH was adjusted to 14 or more with an aqueous sodium hydroxide solution (10% w/w), and the mixture was centrifuged to separate layers, thereby obtaining a solid portion mainly composed of a polyvinyl alcohol/cupric ion chelate and a liquid portion mainly composed of a polyhydroxy substance/cupric ion complex.

Adding 2ml of water into the solid part to form a suspension, shaking down, and dropwise adding 20% hydrochloric acid into the suspension until the solid is completely dissolved to form a uniform green-blue solution; shaking, adding a little zinc powder (more than 200 meshes) into the solution in several times until copper ions are reduced to copper element and separated out, and the green-blue solution becomes colorless; the colorless solution was centrifuged and the pH of the solution was adjusted to 7 to give solution 2.

Dropwise adding hydrochloric acid into the liquid part until the pH value is 1, shaking, and adding a little zinc powder (more than 200 meshes) in several times until the solution turns colorless; the colorless solution was centrifuged and the pH of the solution was adjusted to 7 to give solution 3.

Respectively drying the solution 1, the solution 2 and the solution 3 to obtain a solid 1, a solid 2 and a solid 3; dissolving 3 kinds of solid with deuterium-substituted water by heating (100 deg.C/30 min or more, and shaking sufficiently to ensure complete dissolution, because polyvinyl alcohol has high viscosity and is dispersed in water slowly); nuclear magnetic hydrogen spectrum scanning is carried out on the three deuterated water solutions to obtain a map 1 (attached figure 13 and attached figure 17), a map 2 (attached figure 14 and attached figure 18) and a map 3 (attached figure 15 and attached figure 19).

Comparing with the corresponding nuclear magnetic spectra (fig. 11, fig. 12 and fig. 16) of the hydrogen protons of the polyhydroxy substance and the polyvinyl alcohol, the proton signal of the spectrum 1 is the summation of the polyvinyl alcohol and the polyhydroxy substance (only mannitol is exemplified here, the chemical shifts of the hydrogen protons of other polyhydroxy substances are very similar to those of the hydrogen protons of mannitol, and also only 1788 polyvinyl alcohol and 1799 polyvinyl alcohol are exemplified here, and the chemical shifts of the hydrogen protons of other polyvinyl alcohol are very similar to those of 1788 polyvinyl alcohol and 1799 polyvinyl alcohol, so that the two are not illustrated one by one).

Comparing the map 2 and the map 3 with the map 1 respectively, the proton signal intensity of the polyhydroxy substance in the map 2 is obviously weakened, and the proton signal intensity of the polyvinyl alcohol in the map 3 is obviously weakened.

The chemical shift of-CH 2-on the polyvinyl alcohol molecule is delta 1.5-1.7, and the chemical shift of-CH-connected with hydroxyl is delta 4.1 or so. Each of the-CH 2-and-CH-groups on the polyol are attached to a hydroxyl group, and the chemical shifts of these protons are in the range of Δ 3.7 to 3.9. When the factors such as sample concentration, temperature, sample tube rotating speed, field sweeping strength (megahertz of nuclear magnetic instrument) are comprehensively matched to obtain better resolution, the-CH- (delta 4.1) on the polyvinyl alcohol and the hydrogen protons (delta 3.7-3.9) on the polyhydroxy substance can be better distinguished, at the moment, the-CH 2- (delta 1.5-1.7) on the polyvinyl alcohol molecule and-CH 2-and-CH- (delta 3.7-3.9) on the polyhydroxy substance are calculated through integration, and the quantitative relation of approximate matching of the polyvinyl alcohol and the polyhydroxy substance can be obtained.

The hydrogen proton nmr signal was resolved as follows:

FIG. 11 shows the standard hydrogen spectra of mannitol, peaks 1101 at-CH 3 and-CH 2, solvent deuterated dimethyl sulfoxide to the right of the deuterated water solvent, and peak 1102 at-OH (. delta.4 or higher).

FIG. 12 shows a hydrogen spectrum of a commercially available polyvinyl alcohol 1788, peak 1201 is-CH 2- (delta 1.5-. delta.1.7), -OCOCH3 (. delta.2.05) at peak 1202, -CH- (delta.4.0-. delta.4.1) at peak 1203, which is linked to-OH and-OCOCH 3, water at peak 1204, and acetate-OCOCH 3 as an impurity at peak 1205.

FIG. 13 shows the hydrogen spectrum of a polyvinyl alcohol 1788/mannitol (1:0.6185w/w) microneedle plate, the peak 1301 is polyvinyl alcohol 1788-CH2- (delta 1.5-delta 1.7), the peak 1302 is mannitol-CH 2-and-CH- (delta 3.7-3.9), the peak 1303 is-CH- (delta 4.0-delta 4.1) in which the polyvinyl alcohol 1788 is connected with-OH and-OCOCH 3, the peak 1304 is water, and the peak 1305 is-OCOCH 3 (delta 2.05) in which the polyvinyl alcohol 1788 is connected.

FIG. 14 shows a hydrogen spectrum of a polyvinyl alcohol 1788/mannitol (1:0.6185w/w) microneedle sheet aqueous solution mainly containing a part of polyvinyl alcohol precipitated by copper ions, wherein a peak 1401 is polyvinyl alcohol 1788-CH2- (delta 1.5-delta 1.7), a peak 1402 is mannitol-CH 2-and-CH- (delta 3.7-3.9), a peak 1403 is-CH- (delta 4.0-delta 4.1) in which the polyvinyl alcohol 1788 is connected with-OH and-OCOCH 3, a peak 1404 is a water peak, and a peak 1405 is-OCOCH 3 (delta 2.05) in which the polyvinyl alcohol 1788 is connected.

FIG. 15 shows a hydrogen spectrum of a supernatant of a polyvinyl alcohol 1788/mannitol (1:0.6185w/w) microneedle sheet aqueous solution after precipitation of copper ions, wherein a peak 1501 is polyvinyl alcohol 1788-CH2- (delta 1.5-delta 1.7), a peak 1502 is mannitol-CH 2-and-CH- (delta 3.7-3.9), a peak 1503 is-CH- (delta 4.0-delta 4.1) in which the polyvinyl alcohol 1788 is connected with-OH and-OCOCH 3, a peak 1504 is a water peak, and a peak 1505 is-OCOCH 3 (delta 2.05) in which the polyvinyl alcohol 1788 is.

Comparing fig. 14 and 15 with fig. 13, respectively, it can be seen that the ratio of polyvinyl alcohol 1788 in the test sample of fig. 14 is significantly increased, while the ratio of mannitol in the test sample of fig. 15 is significantly increased.

FIG. 16 shows a diagram of a self-measured hydrogen spectrum of a commercial polyvinyl alcohol 1799, wherein a peak 1601 is-CH 2- (delta 1.7), a peak 1602 is-CH- (delta 4.0), a peak 1603 is a water peak, a peak 1604 is an impurity acetate-OCOCH 3, and a peak 1605 is an impurity methoxy-OCH 3.

FIG. 17 shows a hydrogen spectrum of a microneedle sheet of polyvinyl alcohol 1799/mannitol (1:0.689w/w), peak 1701 is-CH 2- (delta 1.7) of polyvinyl alcohol 1799, peak 1702 is mannitol-CH 2-and-CH- (delta 3.7-3.9), peak 1703 is-CH- (delta 4.0) of polyvinyl alcohol 1799, peak 1704 is a water peak, and peak 1705 is residual-OCOCH 3.

FIG. 18 shows hydrogen spectra of aqueous solutions of polyvinyl alcohol 1799/mannitol (1:0.689w/w) microneedle sheet in which copper ions precipitate and polyvinyl alcohol predominates: peak 1801 is-CH 2- (delta 1.7) of polyvinyl alcohol 1799, peak 1802 is mannitol-CH 2-and-CH- (delta 3.7-3.9), peak 1803 is-CH- (delta 4.0) of polyvinyl alcohol 1799, peak 1804 is water peak, and peak 1805 is residual-OCOCH 3.

FIG. 19 shows a hydrogen spectrum of a supernatant, mainly mannitol, of an aqueous solution of a polyvinyl alcohol 1799/mannitol (1:0.689w/w) microneedle sheet, after precipitation of copper ions, with a peak 1901 as an impurity, namely acetate-OCOCH 3, a peak 1902 as mannitol-CH 2-and-CH- (delta 3.7-3.9), and a peak 1903 as a water peak.

Comparing fig. 18 and 19 with fig. 17, respectively, it can be seen that the ratio of polyvinyl alcohol 1799 in the test sample of fig. 18 is significantly increased, while the ratio of mannitol in the test sample of fig. 19 is significantly increased.

In the operation, the zinc powder is added to reduce copper ions into copper element, precipitate and separate the copper element, so that the copper ions are prevented from interfering a hydrogen spectrum scavenging field; the pH value of the solution is adjusted to about 7 so as to ensure that acetyl groups on the incompletely alcoholyzed polyvinyl alcohol molecules are not hydrolyzed and shed by catalysis of acid and alkali when the solution is evaporated to dryness.

The prepared microneedle carrying the drug can be identified by the same method as the blank microneedle, and if the carried drug has influence on the identification, the needle tip part of the microneedle carrying the drug can be cut off and then identified by the same method.

Example 12: drug efficacy test of insulin microneedles

Diabetes model pig: three male Bama pigs (average weight 8.8kg) of 2 months of age were purchased, and after three weeks of feeding (average weight 11kg), streptozotocin was intravenously injected at a dose of 120mg/kg (Hippon Biotech (Shanghai) Co.); after one week, the diabetes model pig is intravenously supplemented with dosage not less than 50mg/kg according to blood sugar rise condition until fasting blood sugar is higher than 11m mol/l in the morning and fasting is continuously maintained for more than 3 h.

Test samples: 1. control drug, insulin injection (xuzhou wan bang pharmaceutical, test nos. B1 and B2); 2. home-made insulin microneedles for experiments (test nos. a1 to a 6): placing insulin powder (Cipang pharmaceutical industry, Xuzhou) in 3% polyvidone water solution (weight ratio of insulin to water solution is 2:8), and mixing; carrying a solution containing insulin on a needle point of a microneedle which is made of polyvinyl alcohol 1799/erythritol (1:0.56 w/w); 3. home-made insulin microneedles (test No. C1): loading the same solution containing insulin on the needle point of a self-made microneedle made of ethylene-vinyl alcohol copolymer; the average drug loading of the experimental microneedle and the comparative microneedle was 9 units (maximum error ± 9%) to prevent the drug effect observation from being influenced by the metering too low.

The test process comprises the following steps: each test was separated by one day of normal feeding. For each test: measuring fasting blood glucose at eight points in the morning, administering the drug (control drug is injected subcutaneously, the insulin microneedle is attached to the ear of a model pig, the self-made insulin microneedle for the experiment is one piece at a time, and the self-made insulin microneedle for the comparison is two pieces at a time), measuring the blood glucose once per hour, finishing the experiment in three hours, and feeding the pig.

The results are plotted in fig. 21 and the results of the drug effect test of insulin-loaded microneedles are shown in the table in fig. 32.

From the table in fig. 32, it can be seen that: insulin microneedle administration is carried out by loading one piece of polyvinyl alcohol 1799/erythritol (1:0.56w/w) base material each time, and the average blood sugar reduction value is 6.77 in three hours on diabetes model pigs (six repeated experiments obtain 6 groups of data: A1-A6); two pieces of ethylene-vinyl alcohol copolymer substrate loaded insulin microneedles (C1) are used for administration each time, the blood glucose reduction value is 5.4 in three hours, and the average value of each piece is only 2.7; the mean reduction of glucose for 7.5 unit insulin injections (two trials: B1 to B2) was 8.85.

Namely, the effective drug dosage of each piece of polyvinyl alcohol 1799/erythritol substrate loaded insulin microneedle is 2.5 times that of the ethylene-vinyl alcohol copolymer substrate loaded insulin microneedle. It is presumed that insulin is relatively firmly adsorbed to the surface of the polyvinyl alcohol 1799/erythritol-based microneedle, and when the tip of the microneedle is pushed into the skin, more drug is taken into the skin, while the surface adsorption of the ethylene-vinyl alcohol copolymer-based microneedle is insufficient, and a part of the drug is pushed out of the skin; similarly, the microneedle is softened after entering the intradermal drug and absorbing body fluid, the polyvinyl alcohol 1799/erythritol base microneedle still can adsorb the soft drug, and the ethylene-vinyl alcohol copolymer base microneedle has insufficient adsorption force on the soft drug and is possibly extruded outside the skin.

Example 13: exenatide drug-loaded microneedle and drug forming property test

Type II diabetes model pigs: eight male Bama pigs (average 9.1kg) of 2 months of age were purchased, and after three weeks of feeding (average weight 12kg), streptozotocin was intravenously injected at a dose of 120mg/kg (next saint Biotech (Shanghai) Co., Ltd.); one week later, according to the blood sugar rising condition, intravenously supplementing dosage not lower than 50mg/kg as appropriate until fasting blood sugar is higher than 11mmol/l in the morning, and continuously maintaining fasting for more than 3h to obtain the diabetes model. These diabetes model pigs were injected with 5ug of exenatide, blood glucose was observed, and one end having a hypoglycemic response to exenatide was selected for experiments.

Test samples: 1. a reference drug, exenatide injection (dosage: 5ug, purchased externally, trade name: Bai Mida); 2. self-made exenatide microneedles (both 24 and 120) were used for the experiments: placing exenatide powder (Sichuan Shengnuo technology) in 3% povidone aqueous solution (the weight ratio of exenatide to povidone aqueous solution is 2:98), and mixing; carrying a solution containing exenatide on a needle tip of a microneedle, wherein the material is polyvinyl alcohol 1799/erythritol (1:0.56 w/w);

the test process comprises the following steps: each test was separated by one day of normal feeding. For each test: measuring fasting blood glucose at eight points in the morning, administering (subcutaneous injection of control drug, and applying exenatide microneedle to the ear of model pig), measuring blood glucose once per hour, ending the experiment three hours, and feeding. The fasting state no dosing test value is a blank fasting control.

The test results are plotted in fig. 22, the pharmacodynamic test results of the exenatide drug-loaded microneedle are shown in the table in fig. 33, and the test data illustrate that:

1. the drug effect of the microneedle with the number of 24 needles is completely the same as that of the microneedle with the number of 120 needles, which indicates that the limitation on drug loading is extremely small;

2. the decrease in the drug effect of the injection in the latter two hours is due to the short half-life of exenatide, while the microneedle has a long-lasting effect.

3. The exenatide drug-loaded micro-needle has the same drug effect as the injection of 5 ug. In the case of 5ug injection, the blood glucose was reduced more rapidly in the first 1 hour and in the following 2 hours. In the case of microneedles, the decrease was slow in the next 2 hours. The drug-loaded micro-needle has the effect of slowly releasing the drug. The 120 needles were comparable in efficacy (hypoglycemic) to the 24 needles, despite the large difference in the number of needles, consistent with the results reported for exenatide having a hypoglycemic efficacy almost independent of dose dependence.

Example 14: the insulin/exenatide integrated microneedle and the drug property, the medication safety and the drug stability thereof are combined.

After the insulin secretion equivalent of type II diabetes is reduced by 8IU, the doctor encourages the use of insulin very much, and after the secretion equivalent is reduced to a certain extent, the doctor encourages the use of insulin and exenatide simultaneously very much, but the two injections cannot be mixed together and can be administered by two injections. There are more than one hundred million people with type II diabetes, and the insulin/exenatide combined microneedle should be a great new and improved drug with great novelty. As the insulin microneedle and the exenatide microneedle are developed successfully and show good curative effect, a large semicircular insulin drug-carrying microneedle and a small semicircular exenatide drug-carrying microneedle sheet can be respectively prepared by slightly changing a mould, and then the two drugs are mechanically stuck and fixed on a substrate with the same circular size to form a combined microneedle for finishing the application of the two drugs at one time. Because the two medicines are respectively supported on different needle bodies and are not contacted with each other, the drug forming property, the medication safety and the medicine stability of the two medicines are the same as those of respective monomer medicine micro-needles, as shown in figure 20, 20 is a full needle, 201 is a micro-needle with a large semicircle for carrying one medicine, 202 is a micro-needle with a small semicircle for carrying the other medicine, and 203 is a back plate for adhesion.

The combined microneedle drug delivery concept has universality and can be used for other drug delivery schemes requiring combined drug delivery.

Example 15: the mixed powder material is directly pressed into a wafer

Test results of materials, mixture ratio, temperature/pressure, hydrophilicity and toughness of blended powder directly pressed into wafer-shaped material

The simple operation process of the substrate wafer manufacturing comprises the steps of firstly building a device according to the sequence shown in the attached drawing 1, replacing a die plate with a backing plate made of the same material during building, placing the blended powder into a through hole of an upper plate, and closing a pressing device for pressing; the device was heated to the forming temperature, pressurized and held for 27 minutes, and the device was cooled to dissociate the wafer. The selection, formulation, temperature, pressure, surface hydrophilicity and toughness of the pressed partial discs are shown in the table in fig. 34.

Note: 1. the pressure intensity of the rectangular green pressure spring of the used die is 28-32kg/cm²；

2. + indicates good and, + indicates good.

Example 16: the blended powder is extruded into particles by mechanical thermal blending and then made into wafers

After the blended powder is mechanically and thermally blended and extruded into particles, the particles are made into the test results of the material, the mixture ratio, the temperature/pressure, the hydrophilicity and the toughness of the wafer.

The simple operation process of the substrate wafer manufacturing comprises the steps of firstly building a device according to the sequence shown in the attached drawing 1, replacing a die plate with a base plate made of the same material during building, placing particles extruded by mechanical thermal blending into through holes of an upper plate, and closing and pressing the device; the device was heated to the forming temperature, pressurized and held for 27 minutes, and the device was cooled to dissociate the wafer. The selection, formulation, temperature, pressure, surface hydrophilicity and toughness of the pressed partial discs are shown in the table in fig. 35.

Note: 1. the strength of the rectangular green pressure spring of the used die is 28-32kg/cm²；

2. + indicates good and, + indicates good.

Example 17: dissociation experiment of blank microneedle and mold plate

Preparing microneedles by using materials with the ratios of erythritol to 1099 polyvinyl alcohol hydroxyl groups of 0.1:1, 0.13:1, 0.15:1, 0.18:1 and 0.2:1 respectively on a die plate with the thickness of 1.5 mm; the thickness of the microneedle round back plate is 1mm so as to ensure the pulling stress of the needle body.

The dissociation method comprises the following steps: 1. the mould plate is stabilized, and the microneedle is pried by a metal sheet; 2. and (5) stabilizing the mould plate, and sucking the back of the microneedle by using a sucking disc to vertically pull. After the dissociation is completed, the shape of the needle body is observed by a 30-time magnifier, the result of the integrity condition of the needle body when the five materials with different proportions are dissociated from the mould plate is shown in a table in a graph 36, and the microneedle with the hydroxyl ratio of more than 0.15:1 can realize more satisfactory dissociation.

Erythritol and polyvinyl alcohol 1099 are selected for the test because the toughness of the materials matched with the erythritol and the polyvinyl alcohol is ideal. The toughness of different materials and the material proportion is different, and the protection range is not influenced by the difference.

Example 18: die plate hole channel residual material removing experiment

Mixing mannitol with 1099, 1799, 2499, 2699, 3299 and 3599 polyvinyl alcohol at a weight ratio of 0.65:1 on a mold plate with a thickness of 1.5mm to obtain microneedle; the microneedle back layer circular plate is cut off, but the needle bodies are still buried in the mold pore passages.

The clearing method comprises the following steps: 1. stirring with boiling water at normal pressure (100 ℃); 2. stirring with pressurized boiling water (118 ℃); the mould plate stands vertically in the water; after the mold is dissolved in water for a certain time, the mold is taken out, the water in the holes is volatilized, and the situation of the pore passage which is not bright (blocked), bright (blocked is reduced) or completely transparent (cleared) is observed by a 30-time magnifier. Hot melt removal of mannitol/XX 99 polyvinyl alcohol of varying degree of polymerization (0.65:1w/w) the results are tabulated in FIG. 37, and the cooking practice for polyvinyl alcohols having a degree of polymerization 2600 or less is acceptable.

Mannitol has low water solubility, XX99 polyvinyl alcohol has slow dissolution rate, and mannitol and XX99 polyvinyl alcohol are selected for strict examination, so that the principle concept and the protection range are not influenced by the strict examination.

Example 19: experiment for keeping shape in needle body skin hole of 17XX polyvinyl alcohol material with different alcoholysis degrees

The needle bodies of different materials have different capacities of keeping shapes in the skin holes. In a greenhouse with the temperature of about 37 ℃ and the relative humidity of about 75%, attaching blank microneedles of different materials to arms, properly wrapping, inserting a temperature and humidity probe to know that the temperature of the microenvironment is 37 ℃ and the relative humidity is more than 95%, and respectively keeping for 1 hour, 2 hours and 3 hours; the shape of the unloaded microneedle is observed by a magnifying glass with the magnification of 30 times, the experimental result of the shape keeping in the skin hole of the needle body made of materials with different alcoholysis degrees is shown in a table in figure 38, and the shape of the polyvinyl alcohol with the alcoholysis degree of more than 88 percent can be well kept in the skin hole.

The polyvinyl alcohols having the same alcoholysis degree and different polymerization degrees have different swellability, and the protection scope is not affected by the polyvinyl alcohols which are not individually exemplified.