Microneedle patch as well as preparation method and application thereof

Abstract

The invention relates to the technical field of pharmaceutical preparations, and discloses a microneedle patch as well as a preparation method and application thereof. The microneedle comprises a substrate and a needle head, the needle head comprises a cavity structure part and a needle tip; two ends of the cavity structure part are respectively connected with the substrate and the non-tip end of the needle tip; a waterproof layer is arranged on the outer surface of the needle head; and the waterproof layer is prepared from an anionic copolymer of methacrylic acid units. Compared with a traditional microneedle carrying medicine through a needle head or a needle tip, the microneedle provided by the invention has the advantages that the large-capacity cavity structure is used for carrying medicine, so that the medicine carrying capacity of the microneedle is improved; the waterproof layer is prepared on the surface of the needle head, so that direct contact between the microneedle and body fluid is effectively buffered, the moisture resistance of the microneedle is improved, the mechanical strength at the transdermal moment can be maintained, the problem that an existing microneedle is rapidly swelled and softened after meeting skin tissue fluid is solved, and the penetration rate is increased; comprising the high-drug-loading-capacity microneedle array can meet the delivery requirement of large-dose drugs.

Description

Technical Field

[0001] The present invention relates to the technical field of pharmaceutical preparations, and particularly relates to a microneedle patch, a preparation method thereof, and an application thereof. Background Art

[0002] The skin is an important organ for the human body to resist the invasion of pathogenic microorganisms. The epidermis is rich in dendritic cells. Once a vaccine (antigen) contacts dendritic cells on the skin surface, the latter will transmit the antigen to the lymph nodes to induce an immune response. The existing vaccine delivery methods mainly include injection, oral administration, and intranasal administration.

[0003] The injection routes of vaccines can be divided into three types according to different injection sites: intradermal, subcutaneous, and intramuscular injections. Among them, intradermal injection is to inject the drug between the epidermis and the dermis, which can not only improve the effect of the vaccine but also reduce the injection dose. However, intradermal injection is likely to cause strong pain to the vaccinated person and may also leave scars; subcutaneous injection is to inject the vaccine into the tissue between the skin and the muscle. This vaccination method can reduce the risk of local neurovascular injury and has fewer adverse reactions. However, subcutaneous injection is also an invasive administration, and the compliance of the vaccinated person is poor; intramuscular injection is to directly enter the muscle tissue layer with the needle at a 90° angle to the skin to deliver the vaccine, which has many disadvantages such as pain, a large amount of medical waste, a relatively large injection volume, and the need for multiple vaccinations, bringing inconvenience to both the operator and the vaccinated person.

[0004] The main types of oral vaccines are live attenuated poliovirus vaccine and rotavirus. Oral administration can enable the vaccine to proliferate at the intestinal mucosa to cause mucosal immunity, but there are many adverse reactions, so it has gradually been replaced by injectable vaccines.

[0005] Nasal mucosa atomization spray simulates the natural infection process and is the most effective way to induce respiratory mucosal immune responses. However, these methods are not suitable for all populations, especially those patients with underlying respiratory diseases (such as chronic obstructive pulmonary disease, spontaneous pneumothorax, or pulmonary bullae) and infant patients. Moreover, the existing preparation technologies are difficult to effectively control the deposition site of inhaled drug particles, resulting in relatively low drug delivery efficiency of intranasal administration.

[0006] To solve the defects of the above-mentioned vaccine delivery methods, researchers have developed a microneedle (MN)-mediated drug delivery system, enabling patients to receive drug treatment painlessly. As an innovative vaccine delivery method, the microneedle drug delivery system has significant advantages in terms of minimally invasive and convenient, and is expected to solve the problems brought by other delivery methods. A microneedle array integrates dozens or hundreds of needle tips with a length of 25 - 2000 μm (mostly 100 - 1500 μm) on about 1 cm 2A patch-type transdermal drug delivery system made on a substrate of a certain area can encapsulate drugs in its matrix, form a large number of micropores in the skin as delivery channels, promote drug penetration through the physical penetration of nano-needle tips, and achieve a rapid transdermal absorption rate and high bioavailability. In addition, by adjusting the length of the microneedles, it is possible to avoid touching the nociceptive nerves distributed in the deep dermis and subcutaneous tissue, thereby improving patient compliance while reducing pain.

[0007] According to different drug release mechanisms, microneedles can be divided into four types: metal microneedles, coated microneedles, hollow microneedles, and biodegradable polymer microneedles. Among them, biodegradable polymer microneedles are a new direction of development, which can effectively improve the safety of microneedles. As a representative of biodegradable polymer microneedles, polymer-soluble microneedles are made of water-soluble polymer materials. Drugs are encapsulated in the needles and can catalyze the degradation of polymer compounds when entering the skin, thereby completing drug release. They have the advantages of being painless, safe, and easy to operate, and are the future development direction of drug transdermal delivery into the body.

[0008] However, the existing biodegradable polymer microneedles still have the following defects: (1) Insufficient vaccine loading: Traditional soluble microneedles (such as hyaluronic acid or gelatin-based) mostly load drugs by needle adsorption or tip embedding. The drug loading capacity is limited by the porosity and volume of the material, which greatly restricts its drug loading capacity, making it difficult for some drugs to reach the dosage required for clinical treatment and hindering its development in clinical applications. Moreover, directly loading liposome vaccines in a water-soluble matrix easily leads to structural damage; (2) Insufficient mechanical strength: Existing microneedles quickly swell and soften when encountering skin tissue fluid, and their mechanical strength will drop sharply during transdermal penetration, seriously affecting the drug delivery efficiency. Summary of the Invention

[0009] The present invention aims to at least solve one of the above technical problems existing in the prior art. For this reason, one of the purposes of the present invention is to provide a microneedle.

[0010] Another purpose of the present invention is to provide a preparation method for such microneedles.

[0011] A third purpose of the present invention is to provide a microneedle patch.

[0012] A fourth purpose of the present invention is to provide the application of such microneedles or microneedle patches.

[0013] In order to achieve the above purposes, the technical solutions adopted by the present invention are as follows:

[0014] The first aspect of the present invention provides a microneedle, comprising a base and a needle tip; the needle tip includes a cavity structure portion and a needle point; both ends of the cavity structure portion are respectively connected to the base and the non-tip of the needle point; the outer surface of the needle tip has a waterproof layer; the preparation material of the waterproof layer includes an anionic copolymer of methacrylic acid units.

[0015] In some embodiments of the present invention, the length of the needle tip is 100 - 1200 μm.

[0016] In some specific embodiments of the present invention, the length of the needle tip is 400 - 800 μm.

[0017] In some embodiments of the present invention, the thickness of the waterproof layer on the outer surface of the needle tip is 0.8 - 1.5 μm.

[0018] In some specific embodiments of the present invention, the thickness of the waterproof layer on the outer surface of the needle tip is 1 - 1.2 μm.

[0019] In some embodiments of the present invention, the length of the cavity structure portion is 85 - 1100 μm.

[0020] In some specific embodiments of the present invention, the length of the cavity structure portion is 300 - 600 μm.

[0021] In some embodiments of the present invention, the ratio of the volume of the cavity structure portion to the total volume of the needle tip is greater than 80%.

[0022] In some specific embodiments of the present invention, the ratio of the volume of the cavity structure portion to the total volume of the needle tip is 85% - 90%.

[0023] In some embodiments of the present invention, the wall thickness of the cavity structure portion is 1 - 2 μm.

[0024] In some specific embodiments of the present invention, the wall thickness of the cavity structure portion is 1 - 1.5 μm.

[0025] In some embodiments of the present invention, the maximum diameter of the cavity structure portion is 100 - 200 μm.

[0026] In some specific embodiments of the present invention, the maximum diameter of the cavity structure portion is 150 - 200 μm.

[0027] In the microneedle provided by the present invention, the needle tip presents a conical shape, which can be divided into a needle point and a cavity structure portion. The cavity structure portion is located at the lower end of the needle point and is connected to the base; the cavity structure portion occupies a large volume, and the outer wall of the needle tip is thin. When the internal cavity is used to load drugs, the drug loading capacity is large, which can meet the dosage required for clinical treatment.

[0028] In some embodiments of the present invention, the cavity structure part is loaded with freeze-dried liposome vaccine.

[0029] In some embodiments of the present invention, the microneedles comprise the following preparation raw materials: water-soluble polymer material, anionic copolymer of methacrylic acid units, photocurable resin, freeze-dried liposome vaccine, water and organic solvent.

[0030] In some embodiments of the present invention, the water-soluble polymer material comprises carboxymethyl cellulose.

[0031] In some specific embodiments of the present invention, the molecular weight of the carboxymethyl cellulose is 10 - 500 kDa; the degree of substitution is 0.5 - 1.2.

[0032] In some embodiments of the present invention, the anionic copolymer of methacrylic acid units comprises polyacrylic acid resin П (PARП).

[0033] In some embodiments of the present invention, the photocurable resin comprises polyester acrylate resin.

[0034] In the present invention, when using photocurable resin to prepare the microneedle substrate, different from conventional soluble raw materials, the photocurable resin can not only quickly complete drying and sealing in a few seconds, but also isolate moisture and protect the integrity of the freeze-dried liposome vaccine.

[0035] In some embodiments of the present invention, the organic solvent is selected from at least one of isopropanol, ethanol, and ethyl acetate.

[0036] In some embodiments of the present invention, the freeze-dried liposome vaccine comprises the following preparation raw materials: lipid component, aqueous phase component, and lyoprotectant.

[0037] In some embodiments of the present invention, the lipid component of the freeze-dried liposome vaccine comprises ((4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate) (ALC-0315), distearoylphosphatidylcholine (DSPC), cholest-5-en-3β-ol (Cholesterol), and phospholipid-polyethylene glycol (DSPE-PEG 2000).

[0038] In some specific embodiments of the present invention, the lipid component of the freeze-dried liposome vaccine is a mixture of ((4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate), distearoylphosphatidylcholine, cholest-5-en-3β-ol, and phospholipid-polyethylene glycol with a molar ratio of 10:50:(37.5 - 39):1.

[0039] In some embodiments of the present invention, the aqueous phase component includes PBS buffer and protein vaccine.

[0040] In some specific embodiments of the present invention, the concentration of the aqueous phase component is 0.2 - 1 mg / mL.

[0041] In some embodiments of the present invention, the lyoprotectant for the freeze-dried liposome vaccine includes trehalose and sucrose.

[0042] In some embodiments of the present invention, the freeze-dried liposome vaccine is prepared by packaging the liposome vaccine using microfluidic technology and then freeze-drying.

[0043] In the present invention, when using microfluidic technology for packaging the liposome vaccine, the particle size of the liposome can be precisely controlled; freeze-drying to form the freeze-dried powder is beneficial to ensuring the integrity of the liposome vaccine structure.

[0044] In some specific embodiments of the present invention, the freeze-dried liposome vaccine is prepared by a method comprising the following steps:

[0045] Take the lipid component and the aqueous phase component, package the liposome vaccine using microfluidic technology, remove the unencapsulated antigen by centrifugation, dialysis or ultrafiltration, calculate the encapsulation efficiency by HPLC method (encapsulation efficiency = amount of encapsulated antigen / total amount of antigen × 100%), use dynamic light scattering (DLS) to detect the particle size of the liposome to obtain the liposome vaccine; add the lyoprotectant to the liposome vaccine and freeze-dry to obtain the freeze-dried liposome vaccine.

[0046] In some embodiments of the present invention, the particle size of the liposome is 80 - 200 nm.

[0047] In some specific embodiments of the present invention, the particle size of the liposome is 80 - 150 nm.

[0048] In some embodiments of the present invention, the dosage of the lyoprotectant is 5 wt% - 30 wt% of the liposome vaccine.

[0049] In some embodiments of the present invention, the freeze-drying includes rapidly cooling to below -40 °C, pre-freezing for 2 - 6 h, and heating to -50 °C to -10 °C under vacuum conditions (0.1 - 0.3 mbar) and maintaining for several hours to several days.

[0050] The second aspect of the present invention provides a method for preparing the microneedle described in the first aspect of the present invention, comprising the following steps:

[0051] S1. Mix the water-soluble polymer material with water to obtain solution A; place the solution A in a microneedle mold, centrifuge, degas, and dry to obtain the needle;

[0052] S2. Fill the freeze-dried liposome vaccine into the cavity structure part of the needle, then add photocurable resin to the non-needle tip of the needle, cure it, and demold to obtain microneedles without a waterproof layer;

[0053] S3. Mix the anionic copolymer of the methacrylic acid unit with an organic solvent to obtain Solution B; soak the microneedles without a waterproof layer in Solution B, take them out and dry to obtain the microneedles of the present invention.

[0054] In some embodiments of the present invention, the microneedle mold is prepared by a method including the following steps:

[0055] Mix dimethyl silicone (PDMS) and a curing agent in a mass ratio of 10:(0.5 - 2), pour it on the surface of a metal male mold, let it stand at room temperature for 5 - 60 min to discharge air bubbles, then heat and cure it at 40 - 60 °C for 20 - 40 min, raise the temperature to 80 °C within 2 h, and then cool it to room temperature and peel it off to obtain a PDMS microneedle mold.

[0056] In some embodiments of the present invention, in step S1, the content of the water-soluble polymer material in Solution A is 8 wt% - 20 wt%.

[0057] In some specific embodiments of the present invention, in step S1, the content of the water-soluble polymer material in Solution A is 15 wt% - 20 wt%.

[0058] In some embodiments of the present invention, in step S1, the rotation speed of the centrifugation is 1000 - 3500 rpm, and the time is 5 - 30 min.

[0059] In some embodiments of the present invention, in step S1, the specific operation of degassing is: place the microneedle mold in a 37 °C vacuum drying oven and evacuate it for 1 - 2 h to remove the residual air bubbles in the solution.

[0060] In some embodiments of the present invention, in step S1, the drying temperature is 55 - 65 °C, and the time is 6 - 24 h.

[0061] In some embodiments of the present invention, in step S2, after filling the freeze-dried liposome vaccine into the needle cavity, level it off, and place the microneedle mold in a horizontal centrifuge at a rotation speed of 1000 - 1500 rpm for 10 - 30 min.

[0062] In some embodiments of the present invention, in step S2, the curing condition is ultraviolet light curing at 365 - 400 nm for 2 - 5 s.

[0063] In some embodiments of the present invention, in step S3, the content of the anionic copolymer of methacrylic acid units in solution B is 1 wt% - 5 wt%.

[0064] In some specific embodiments of the present invention, in step S3, the content of the anionic copolymer of methacrylic acid units in solution B is 1 wt% - 3 wt%.

[0065] In some embodiments of the present invention, in step S3, the soaking time is 1 - 10 min.

[0066] In some specific embodiments of the present invention, in step S3, the soaking time is 1 - 5 min.

[0067] In some embodiments of the present invention, in step S3, the drying is carried out at room temperature for 10 - 60 min.

[0068] The third aspect of the present invention provides a microneedle patch, comprising an array composed of the microneedles described in the first aspect of the present invention; the density of the array is 50 - 200 needles / cm 2 。

[0069] In some embodiments of the present invention, the density of the needle array is 50 - 100 needles / cm 2 。

[0070] The fourth aspect of the present invention provides the use of the microneedles described in the first aspect, or the microneedle patch described in the third aspect, in the preparation of drugs.

[0071] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0072] 1) The microneedles provided by the present invention, compared with the traditional microneedles that carry drugs through the needle or the tip of the needle, use a large-capacity cavity structure to load drugs, effectively improving the drug loading capacity of the microneedles; by preparing a waterproof layer on the surface of the needles, the present invention effectively buffers the direct contact between the micro-head and body fluids, improves the moisture resistance of the microneedles, can maintain the mechanical strength during transdermal penetration, solves the problem that the existing microneedles quickly swell and soften after encountering skin tissue fluid, and improves the microneedle penetration rate;

[0073] 2) The microneedles provided by the present invention are prepared with a water-soluble polymer material including carboxymethyl cellulose for the needles, endowing the microneedles with biocompatibility; an anionic copolymer of methacrylic acid units including polyacrylic resin П is used to prepare the waterproof layer, endowing the microneedles with good moisture resistance and mechanical strength; a photocurable resin is used to prepare the substrate, which can quickly complete drying and sealing, isolate moisture, and protect the integrity of the liposome vaccine lyophilized powder in the cavity;

[0074] 3) The preparation method of the microneedles provided by the present invention has simple steps and is suitable for industrial application.

[0075] 4) The microneedle patch provided by the present invention includes a number of microneedles with high drug loading capacity, which can meet the delivery requirements of large doses of drugs. Description of the Drawings

[0076] Figure 1 It is a three-dimensional structure diagram of the needle in the microneedle patch of the embodiment;

[0077] Figure 2 It is an SEM image of the needle in the microneedle patch of the embodiment;

[0078] Figure 3 It is a physical image of the needle in the microneedle patch of the embodiment;

[0079] Figure 4 It is a comparison chart of the influence of humidity on the morphology and needle sharpness of microneedles in Test Example 1;

[0080] Figure 5 It is a comparison chart of the influence of humidity and pressure on the morphology and needle sharpness of microneedles in Test Example 2;

[0081] Figure 6 It is the fluorescence quantitative result of rhodamine B for the drug loading capacity of microneedles in Test Example 3;

[0082] Figure 7 It is the quantitative result of OVA protein for the drug loading capacity of microneedles in Test Example 3;

[0083] Figure 8 It is a comparison chart of the influence of the waterproof layer on the outer surface of the needle on the dissolution of microneedles in Test Example 4;

[0084] Figure 9 It is a comparison chart of the influence of the waterproof layer on the outer surface of the needle on the drug release rate of microneedles in Test Example 4;

[0085] Figure 10 It is a physical image of the microneedle patch of the embodiment being pressed into pigskin in Test Example 5;

[0086] Figure 11 It is a comparison chart of the mechanical strength of microneedles in Test Example 5;

[0087] Figure 12 It is a comparison chart of the protein delivery efficiency in Test Example 6;

[0088] Figure 13 It is a statistical chart of the data of the protein delivery efficiency in Test Example 6. Detailed Description of the Invention

[0089] The content of the present invention will be further described in detail through specific embodiments below. Unless otherwise specified, the raw materials, reagents or devices used in the embodiments can be obtained from conventional commercial channels or can be obtained by existing technical methods. Unless otherwise specified, the test or testing methods are all conventional methods in the art.

[0090] Example

[0091] In this example, a microneedle patch was prepared as follows:

[0092] S11: Mix dimethyl silicone and a curing agent in a mass ratio of 10:1, pour it on the surface of a metal male mold, let it stand at room temperature for 60 min to discharge air bubbles, then heat and cure it at 55 °C for 30 min, raise the temperature to 80 °C within 2 h, and then cool it to room temperature. After that, peel off the cured PDMS mold to obtain a microneedle mold;

[0093] S12: Mix the water-soluble polymer material carboxymethyl cellulose (molecular weight 250000 Da, degree of substitution 0.5 - 1.2) with water to prepare solution A with a concentration of 20 wt%;

[0094] S13: Place solution A in the microneedle mold, keep at room temperature, and centrifuge the mold horizontally at 1000 rpm, 2500 rpm, and 3500 rpm for 10 min in sequence;

[0095] S14: Scrape off the excess solution A on the surface of the mold and inside the mold cavity, place the mold in a 37 °C vacuum drying oven and evacuate for 1 h to remove the residual air bubbles in the solution;

[0096] S15: Place the mold in a 60 °C drying oven and heat for 6 h to form a needle array with axial cavities after drying;

[0097] S21: Mix ALC-0315, DSPC, Cholesterol, and DSPE-PEG2000 in a molar ratio of 10:50:37.5:2.5 as the lipid component, and mix PBS buffer and protein vaccine to obtain an aqueous phase component with a concentration of 0.7 mg / mL;

[0098] S22: Realize the packaging of liposome vaccine through microfluidic technology to accurately control the particle size of liposomes; remove unencapsulated antigen by centrifugation, dialysis or ultrafiltration, calculate the encapsulation efficiency to be 98% by HPLC method; use dynamic light scattering to detect the particle size of liposomes to be 100 nm;

[0099] S23. After adding a 10 wt% sucrose solution to the liposome vaccine obtained in step S22, quickly cool it to below -40 °C to avoid excessive ice crystals from damaging the liposome structure. Pre-freeze for 6 h, and then heat it to -50 °C to -10 °C under a vacuum condition of 0.1 bar and maintain for several hours to several days. After the ice crystals sublimate, the freeze-dried powder of the liposome vaccine is obtained;

[0100] S24. Add the freeze-dried powder of the liposome vaccine obtained in step S23 into the cavity structures of each needle tip obtained in step S15, level it, and then place the mold in a horizontal centrifuge at rotational speeds of 1000 rpm and 1500 rpm for 10 min in sequence;

[0101] S25. Add polyester acrylate resin to the non-needle tip of the needle, cure it under ultraviolet light irradiation at 365 nm for 3 s, and then demold to obtain a microneedle patch without a waterproof layer;

[0102] S31. Mix polyacrylic resin II with isopropanol to obtain solution B with a concentration of 2 wt%. Immerse the microneedle patch without a waterproof layer obtained in step S25 in solution B for 5 min and then take it out to form a waterproof layer. After drying at room temperature for 60 min, a microneedle patch with a cavity structure and a waterproof coating is obtained. The base area of the patch is 1 cm 2 , and the density of the needle array on the base is 77 needles / cm 2 .

[0103] Figure 1 is a schematic three-dimensional structure diagram of the needle in the microneedle patch of the example. As can be seen from Figure 1 , the needle has a conical-like cavity structure, which can be divided into a cavity structure part and a needle tip part. The total length of the needle is 600 μm, the length of the cavity structure part is 450 μm, the length of the needle tip is 150 μm, the maximum diameter of the cavity structure part is 200 μm, and the volume of the cavity structure part accounts for about 90% of the total volume of the needle.

[0104] Figure 2 is the SEM image of the needle in the microneedle patch of the example. Among them, Figure 2 in (a) is the SEM image of the needle before breaking, Figure 2 in (b) is the SEM image of the needle before being completely broken, Figure 2 in (c) is the SEM image of the needle after being broken at 90°, Figure 2 in (d) is the SEM image of the wall thickness of the cavity structure part and the thickness of the waterproof layer after being broken at 90°. As can be seen from Figure 2 , for the microneedle patch prepared in the example, the wall thickness of the cavity structure part of the needle is only 1.36 μm, and the waterproof layer is evenly coated on the surface of the needle with a thickness of 1.15 μm.

[0105] Figure 3 is the physical image of the needle in the microneedle patch of the example. Among them, Figure 3In which, (a) is a physical diagram of the needle array, Figure 3 in which, (b) is a physical diagram of the needle before loading the freeze-dried liposome vaccine, Figure 3 in which, (c) is a physical diagram of the needle after loading the freeze-dried liposome vaccine.

[0106] From Figures 1-3 it can be seen that in the microneedle patch prepared in Example 1, the needle has a relatively large cavity volume and a relatively thin wall thickness, which is beneficial to improving the drug loading capacity of the microneedle.

[0107] Test Example 1

[0108] Taking ordinary cavity microneedles as a comparison, to explore the influence of humidity on the morphology and sharpness of microneedles:

[0109] The ordinary cavity microneedles and the microneedle patch in the example were placed at 37 °C and 40% relative humidity for 7 days, and the morphology of the microneedles was observed on the 1st day, the 3rd day and the 7th day respectively.

[0110] Figure 4 Figure for comparing the influence of humidity on the morphology and sharpness of microneedles in Test Example 1. From Figure 4 it can be seen that compared with ordinary cavity microneedles, in the microneedle patch prepared in the example, the needles maintained good morphology and sharpness within 1 - 7 days, and the change was small compared with the 1st day; while the sharpness of the needles of ordinary microneedles decreased on the 3rd day, and the morphology of the microneedles was damaged on the 7th day, indicating that compared with ordinary cavity microneedles, the microneedle patch prepared in the example is less affected by humidity because the outer surface of the needle has a waterproof layer.

[0111] Test Example 2

[0112] The ordinary cavity microneedles and the microneedle patch in the example were placed at 37 °C and 100% relative humidity for 24 hours, and a pressure of 500 g was applied to observe the influence of humidity and pressure on the morphology and sharpness of the microneedles.

[0113] Figure 5 Figure for comparing the influence of humidity and pressure on the morphology and sharpness of microneedles in Test Example 2. From Figure 5 it can be seen that compared with ordinary cavity microneedles, in the microneedle patch prepared in the example, the needles were bent to a certain extent under high humidity and pressure factors, while the ordinary cavity microneedles were completely broken under this condition of pressure, indicating that compared with ordinary cavity microneedles, the needles of the microneedle patch prepared in the example are less affected by humidity and have a certain mechanical strength and can withstand a certain pressure.

[0114] Test Example 3

[0115] Compare the drug loading capacities of solid microneedles of the same size and the microneedle patch in the examples: Fill 700 μg of the same freeze-dried liposome protein vaccine into each of the two types of microneedles. Redissolve the microneedles loaded with the freeze-dried powder, and detect the amount of protein dissolved. Use rhodamine B fluorescence quantification and OVA protein quantification to quantify the drug loading capacities of the two types of microneedles respectively.

[0116] Figure 6 Figure 4 shows the results of rhodamine B fluorescence quantification of the drug loading capacity of the microneedles in Test Example 3. Among them, Figure 6 (a) in it is the standard curve of rhodamine B, Figure 6 (b) in it is the comparison of the drug loading capacities of the microneedles; Figure 7 Figure 5 shows the results of OVA protein quantification of the drug loading capacity of the microneedles in Test Example 3. Among them, Figure 7 (a) in it is the standard curve of OVA protein, Figure 7 (b) in it is the comparison of the drug loading capacities of the microneedles. From Figure 6 and Figure 7 it can be seen that for the microneedle patch in the examples, the drug loading capacity of the needle head with a cavity structure can be 10 times that of the solid microneedle of the same size, and the drug loading capacity is significantly improved, which is beneficial to solving the problem of low drug loading of microneedles in clinical applications.

[0117] Test Example 4

[0118] Taking ordinary cavity microneedles as a comparison, explore the influence of the waterproof layer on the outer surface of the needle head on the dissolution of microneedles and the drug release rate: Load the same amount of rhodamine B into both types of microneedles, insert the two types of microneedles into the agarose nucleic acid gel respectively, and record the dissolution time of the microneedles; Load the same amount of protein vaccine mixed powder into both types of microneedles, put the two types of microneedles into physiological saline, take out the physiological saline at regular intervals to detect the corresponding amount of protein, and monitor the drug release rates of the two types of microneedles.

[0119] Figure 8 Figure 6 is a comparison chart of the influence of the waterproof layer on the outer surface of the needle head on the dissolution of microneedles in Test Example 4. From Figure 8 it can be seen that compared with ordinary microneedles, the microneedles with a waterproof layer in the examples also began to dissolve and release within 5 minutes. That is, adding a waterproof layer on the outer surface of the needle head does not affect the dissolution of the microneedles while improving the moisture resistance of the microneedles.

[0120] Figure 9 Figure 7 is a comparison chart of the influence of the waterproof layer on the outer surface of the needle head on the drug release rate of microneedles in Test Example 4. From Figure 9 it can be seen that compared with ordinary microneedles, the drug release rate of the microneedles with a waterproof layer in the examples is a little slower, but it does not affect the complete release of the drug.

[0121] Test Example 5

[0122] Press the ordinary hollow microneedles and the microneedle patch in the example into the pig skin, and compare the mechanical strength of the ordinary hollow microneedles and the microneedle patch in the example.

[0123] Figure 10 Figure (a) in [ ] is a photo of the operation process of pressing the microneedle patch in the example into the pig skin in Test Example 5. Figure 10 In it, (a) is a photo of the operation process; Figure 10 In (b) of [ ] and Figure 10 In (c) of [ ] are photos of the holes on the surface of the pig skin at different magnifications. As can be seen from Figure 10 it, the needles of the microneedle patch in the example have good mechanical strength and can successfully form holes with uniform pore diameters on the surface of the pig skin.

[0124] Figure 11 Figure [ ] is a comparison chart of the mechanical strength of the microneedles in Test Example 5. As can be seen from Figure 11 it, compared with ordinary microneedles, the microneedle patch in the example has stronger mechanical strength, better transdermal effect, and is more conducive to the application of microneedles in vaccine delivery.

[0125] Test Example 6

[0126] Compare the protein delivery efficiency of the microneedle patch in the example, ordinary hollow microneedles, and subcutaneous injection.

[0127] Figure 12 Figure [ ] is a comparison chart of the protein delivery efficiency in Test Example 6. Among them, Figure 12 in (a) of [ ] is subcutaneous injection of fluorescent protein, Figure 12 in (b) of [ ] is delivery of fluorescent protein by ordinary hollow microneedles, Figure 12 in (c) of [ ] is delivery of fluorescent protein by the microneedle patch in the example, Figure 12 in (d) of [ ] is the negative control; Figure 13 Figure [ ] is a statistical chart of the data of the protein delivery efficiency in Test Example 6. As can be seen from Figure 12 and Figure 13 it, compared with subcutaneous injection of fluorescent protein, the efficiency of delivering fluorescent protein by ordinary hollow microneedles is greatly reduced, while the delivery amount of fluorescent protein by the microneedle patch in the example is comparable to that of the subcutaneous injection group, indicating that the microneedles and microneedle patches provided by the present invention effectively improve the drug delivery rate of microneedles.

Claims

1. A microneedle, characterized in that: It comprises a base and a needle; the needle comprises a cavity structure part and a needle tip; the two ends of the cavity structure part are respectively connected to the base and the non-tip end of the needle tip; the outer surface of the needle tip has a waterproof layer; The preparation material of the waterproof layer includes an anionic copolymer of methacrylic acid units.

2. The microneedle according to claim 1, characterized in that The length of the needle is 100-1200 μm; And / or, the thickness of the waterproof layer on the outer surface of the needle is 0.8-1.5 μm.

3. The microneedle according to claim 1, characterized in that The length of the cavity structure portion is 85-1100 μm; and / or, the ratio of the volume of the cavity structure portion to the total volume of the needle is greater than 80%; And / or, the wall thickness of the cavity structure portion is 1-2 μm; And / or, the maximum diameter of the cavity structure portion is 100-200 μm.

4. The microneedle according to claim 1, characterized in that The cavity structure part is loaded with liposome vaccine freeze-dried powder.

5. The microneedle according to any one of claims 1 to 4, characterized in that: The microneedle comprises the following preparation raw materials: water-soluble polymer material, anionic copolymer of methacrylic acid unit, light-curable resin, liposome vaccine freeze-dried powder, water and organic solvent.

6. The microneedle according to claim 5, characterized in that The water-soluble polymer material includes carboxymethyl cellulose; And / or, the anionic copolymer of methacrylic acid units comprises polyacrylic acid resin II.

7. The method for preparing a microneedle according to claim 5 or 6, characterized in that: The following steps are involved: S1. Mixing a water-soluble polymer material with water to obtain a solution A; placing the solution A in a microneedle mold, centrifuging, degassing, and drying to obtain the needle tip; S2, filling the cavity structure part of the needle with liposome vaccine freeze-dried powder, adding light-curable resin to the non-needle tip of the needle, curing, and demolding to obtain a microneedle without a waterproof layer; S3, mixing the anionic copolymer of methacrylic acid units with an organic solvent to obtain a solution B; immersing the microneedle without a waterproof layer in the solution B, taking out and drying to obtain the microneedle.

8. The preparation method according to claim 7, characterized in that: In step S1, the content of the water-soluble polymer material in solution A is 8wt%-20wt%; And / or, in step S2, the curing condition is 365-400nm ultraviolet light curing for 2-5s; And / or, in step S3, the content of the anionic copolymer of methacrylic acid units in solution B is 1wt%-5wt%; and the immersion time is 1-10 min.

9. A microneedle patch, characterized in that: An array comprising the microneedles of any one of claims 1 to 6; the density of the array is 50 to 200 microneedles / cm 2 .

10. Use of the microneedle according to any one of claims 1 to 6, or the microneedle patch according to claim 9 in drug preparation.

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