Microneedle patch and preparation method therefor

Abstract

The present invention relates to a microneedle patch and a preparation method therefor, wherein the microneedle is prepared by using a solvent exchange method. Compared with the prior art, the present invention has the following advantages: first, mild temperature conditions are used, so that a heat-sensitive drug such as a protein can remain stable; second, the residual amount of a solvent can be adjusted more flexibly by means of adjusting the number of cycles, temperature, duration, etc., in the solvent exchange, so that sustained-release structures in different states can be obtained according to administration requirements; and third, the base portion of the needle body is not adhered, so that each needle body can maintain an independent and good form.

Description

Microneedle patch and preparation method thereof Technical Field

[0001] The present invention relates to the field of biomedicine technology, and in particular to a microneedle patch and a preparation method thereof. Background Art

[0002] In recent years, microneedles have attracted widespread attention as one of the physical penetration enhancement technologies for transdermal drug delivery. They can pierce the stratum corneum and use the micron-scale physical channels formed in the skin to deliver drugs into the systemic circulation or accumulate in specific areas.

[0003] Compared to other drug delivery systems, microneedles offer advantages such as convenient and painless administration, and are highly adaptable to patients. When microneedles incorporate both immediate-release and sustained-release layers, the released drug can maintain long-lasting efficacy, achieving excellent therapeutic effects for recurrent diseases. However, existing microneedle structures are generally solid. When the drug or microneedle matrix is ​​liquid or semisolid, the microneedles cannot be molded or lack sufficient mechanical strength to penetrate the skin's stratum corneum, failing to meet drug delivery requirements. Summary of the Invention

[0004] The first aspect of the present invention is to provide a microneedle patch, comprising a base layer and a needle body, wherein the needle body comprises a quick-release layer and a sustained-release layer, wherein the sustained-release layer is located inside the quick-release layer and is semisolid.

[0005] In some embodiments, the liquid content in the sustained-release layer is no more than 40%.

[0006] In some embodiments, the sustained-release layer comprises a matrix A, and the matrix A comprises a hydrophobic high molecular polymer.

[0007] In some embodiments, the immediate-release layer comprises a matrix B, and the matrix B comprises a hydrophilic polymer.

[0008] In some embodiments, the sustained-release layer comprises a matrix A, the immediate-release layer comprises a matrix B, the matrix A comprises a hydrophobic polymer, and the matrix B comprises a hydrophilic polymer.

[0009] In some embodiments, the hydrophobic polymer is one or more of polyglycolic acid, polylactic acid, polylactic acid-co-glycolic acid, polycaprolactone, polyanhydride, polyurethane, polyesteramide, polyorthoester, polydioxanone dioxanone, polyacetal, polyketal, polycarbonate, polyorthocarbonate, polyphosphazene, polyhydroxybutyrate, polyhydroxyvalerate, polyalkylene oxalate, polyalkylene succinate, and polymalic acid, preferably polylactic acid-co-glycolic acid or polylactic acid;

[0010] The hydrophilic high molecular polymer is one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol and its derivatives, polyvinyl pyrrolidone and its derivatives, hyaluronic acid and its derivatives, chondroitin sulfate, chitosan and its derivatives, maltose derivatives, and polyacrylamide derivatives, preferably hyaluronic acid and its derivatives.

[0011] In some embodiments, the weight average molecular weight of the polylactic acid-glycolic acid copolymer is 2,000 to 100,000; and the monomer ratio of lactic acid to glycolic acid in the polylactic acid-glycolic acid copolymer is 50:50 to 100:0.

[0012] In some embodiments, the matrix B further comprises a small molecule protective agent, which is one or more of trehalose, glucose, fructose, starch, sucrose, glucose, maltose, lactose, lactulose, fructose, turanose, raffinose, melezitose, dextran, sorbitol, mannitol, and xylitol.

[0013] In some embodiments, the sustained-release layer arbitrarily includes at least one active ingredient A, and the active ingredient A is selected from a pharmaceutical active ingredient, a cosmetic active ingredient, a health product active ingredient or a medical beauty active ingredient; in some preferred embodiments, the pharmaceutical active ingredient is hepatitis B virus surface antigen.

[0014] In some embodiments, the immediate-release layer arbitrarily includes at least one active ingredient B, and the active ingredient B is selected from a pharmaceutical active ingredient, a cosmetic active ingredient, a health product active ingredient or a medical aesthetic active ingredient; in some preferred embodiments, the pharmaceutical active ingredient is hepatitis B virus surface antigen.

[0015] In some embodiments, the sustained-release layer comprises hepatitis B virus surface antigen.

[0016] In some embodiments, the weight ratio of the active ingredient A to the matrix A is 1:5 to 1:40;

[0017] In some embodiments, the weight ratio of the active ingredient B to the matrix B is 1:200 to 1:400.

[0018] In some embodiments, the length of the needle body is 100-1500 μm, the thickness of the base layer is 10-100 μm, and the density of the needle body is: 25-1000 needle bodies per square centimeter of the base layer.

[0019] In some embodiments, the total length of the needle body is 750 μm, and the length of the sustained-release layer is 500 μm.

[0020] In some embodiments, the sustained-release layer contains a dye, such as Sudan Red.

[0021] In some embodiments, the base layer includes a biocompatible polymer material, and the biocompatible polymer material is one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol and its derivatives, polyvinyl pyrrolidone and its derivatives, sodium hyaluronate, chondroitin sulfate, dextran, silk protein, and gelatin; in some preferred embodiments, the biocompatible polymer material is polyvinyl pyrrolidone.

[0022] The second aspect of the present invention is to provide a microneedle patch loaded with hepatitis B virus surface antigen, comprising a base layer and a needle body, the needle body comprising a quick-release layer and a sustained-release layer, the sustained-release layer being located inside the quick-release layer, the sustained-release layer being semisolid, the sustained-release layer comprising a matrix A and hepatitis B virus surface antigen, the matrix A comprising a polylactic acid-glycolic acid copolymer, the quick-release layer comprising a matrix B and hepatitis B virus surface antigen, the matrix B comprising hyaluronic acid.

[0023] Another aspect of the present invention is to provide a method for preparing the above-mentioned microneedle patch, comprising the following steps: first preparing a sustained-release layer in a mold, and then preparing a quick-release layer, wherein the sustained-release layer is prepared by a solvent exchange method.

[0024] In some embodiments, the method for preparing a sustained-release layer comprises the following steps: preparing a sustained-release layer solution comprising a hydrophobic high molecular polymer, filling a mold with the sustained-release layer solution, and solidifying the sustained-release layer solution by a solvent exchange method;

[0025] A dye, such as Sudan Red, may also be added to the sustained-release layer solution of the present invention.

[0026] In some embodiments, the method for preparing a quick-release layer comprises the following steps: preparing a quick-release layer solution comprising a hydrophilic polymer, filling the quick-release layer solution into a mold after the sustained-release layer solution is solidified, and solidifying the quick-release layer solution.

[0027] In some embodiments, the solvent of the sustained-release layer solution is one or more of N-methylpyrrolidone, dimethyl sulfoxide, dimethylformamide, tetrahydrofuran, triethylglycerol, benzyl benzoate, ethyl benzoate, triethanolamine, dioxane, polyethylene glycol, methoxypolyethylene glycol, alkoxypolyethylene glycol, polyethylene glycol ester, 2-pyrrolidone, dimethylacetamide, acetone, methyl acetate and ethyl acetate, preferably N-methylpyrrolidone.

[0028] In some embodiments, the hydrophobic polymer is one or more of polyglycolic acid, polylactic acid, polylactic acid-glycolic acid copolymer, polycaprolactone, polyanhydride, polyurethane, polyesteramide, polyorthoester, polydioxanone dioxanone, polyacetal, polyketal, polycarbonate, polyorthocarbonate, polyphosphazene, polyhydroxybutyrate, polyhydroxyvalerate, polyalkylene oxalate, polyalkylene succinate, and polymalic acid, preferably one of polylactic acid-glycolic acid copolymer and polylactic acid.

[0029] In some embodiments, the hydrophilic high molecular polymer is one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol and its derivatives, polyvinyl pyrrolidone and its derivatives, hyaluronic acid and its derivatives, chondroitin sulfate, chitosan and its derivatives, maltose derivatives, and polyacrylamide derivatives, preferably hyaluronic acid and its derivatives.

[0030] In some embodiments, the solvent of the immediate-release layer solution is water or a mixture of a polar solvent and water, preferably water.

[0031] The solvent exchange method comprises the following steps: adding a poor solvent for a hydrophobic polymer into the small holes of the mold filled with the sustained-release layer solution, and removing the exchange solvent after a period of solvent exchange.

[0032] In some embodiments, the solvent exchange temperature is 0 to 40°C and the time is 5 minutes to 24 hours;

[0033] In some embodiments, the concentration of the hydrophobic polymer in the sustained-release layer solution is 0.1 to 80%. Preferably, the concentration of the hydrophobic polymer in the sustained-release layer solution is 5 to 50%.

[0034] In some embodiments, the concentration of the hydrophilic polymer in the rapid-release layer solution is 0.1 to 80%; preferably, the concentration of the hydrophilic polymer in the rapid-release layer solution is 1 to 30%.

[0035] In some embodiments, the steps of filling the mold with the sustained-release layer solution and the immediate-release layer solution comprise centrifugation or negative pressure vacuuming.

[0036] In some embodiments, the method of solidifying the immediate-release layer solution is drying solidification.

[0037] In some embodiments, the solvent exchanging step is performed in a shaking incubator.

[0038] In some embodiments, the poor solvent for the hydrophobic polymer is water, ethanol, or n-hexane, preferably water.

[0039] In some embodiments, the drying and curing temperature is 20-40°C, preferably 26-36°C.

[0040] In some embodiments, the drying and curing time is 5 to 24 hours, preferably 8 to 12 hours.

[0041] In some embodiments, the weight average molecular weight of the polylactic acid-glycolic acid copolymer is 2,000 to 100,000; and the monomer ratio of lactic acid to glycolic acid in the polylactic acid-glycolic acid copolymer is 50:50 to 100:0.

[0042] In another aspect, the present invention provides the use of the above-mentioned microneedle patch in the preparation of products for disease diagnosis, treatment, prevention, health care, medical beauty, and skin care.

[0043] The beneficial effects of the present invention are as follows:

[0044] (1) The microneedles of the present invention have both a sustained-release layer and a rapid-release layer. If the sustained-release layer and the rapid-release layer are loaded with the same active pharmaceutical ingredient, they can release the drug for a long time, maintain stable blood drug concentration, avoid peaks and valleys, and reduce toxic side effects. If they are loaded with different active pharmaceutical ingredients, they can also be used as a compound preparation to achieve combined treatment.

[0045] (2) The microneedle prepared by the present invention has a sustained-release layer located inside the quick-release layer, and the needle body has good mechanical strength and can successfully puncture the skin without breaking or disintegrating.

[0046] (3) The sustained-release layer is solidified by the solvent exchange method. The residual amount of solvent and the amount of polymer precipitation solidification can be flexibly adjusted by adjusting the temperature and time of the solvent exchange, thereby adjusting the state of the obtained sustained-release layer to either solid or semi-solid. As the state of the sustained-release layer changes, the microneedles can achieve sustained-release effects with varying drug release times and amounts, thereby fully meeting different drug loading requirements. In addition, the solvent exchange method has a mild temperature and will not destroy the stability of heat-sensitive drugs, which is more advantageous than existing technologies.

[0047] (4) After the microneedle penetrates the stratum corneum, the immediate-release layer dissolves rapidly, and the needle separates from the basal layer, leaving the sustained-release layer in the body. The microneedle basal layer can be peeled off within a short period of time after administration, enhancing patient adaptability without affecting drug efficacy. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] FIG1 is a schematic structural diagram of the microneedle patch of the present invention.

[0049] FIG2 is an optical microscope image of the drug-loaded microneedle patch obtained in Example 1 at different scales (ac).

[0050] FIG3 is a macroscopic image (a) and a microscopic image (b) of the sustained-release layer of the drug-loaded microneedle patch obtained in Example 1 after dissolution in water.

[0051] FIG4 is a macroscopic image (a) of the sustained-release layer of the microneedle patch obtained in Comparative Example 1 and a microscopic image (b) of the sustained-release layer after dissolution in water.

[0052] FIG5 is a diagram showing the dissolution process of the drug-loaded microneedle patch obtained in Example 1 in vitro.

[0053] FIG6 is a graph showing the results of the skin penetration test of the drug-loaded microneedle patch obtained in Example 1.

[0054] FIG7 is a graph showing the in vitro release curves of the drug-loaded microneedle patches obtained in Examples 2, 3, and 4.

[0055] FIG8 is a graph showing the results of the immunization experiment on mice using the drug-loaded microneedle patch obtained in Example 2 and subcutaneously injected hepatitis B vaccine. DETAILED DESCRIPTION

[0056] In the present invention, unless otherwise specified, "%" refers to the percentage by mass (w / w).

[0057] In the present invention, the terms "matrix A" and "matrix B" actually refer to matrices, wherein "A" and "B" are only used to distinguish between different layers of the needle body.

[0058] In the present invention, the English and Chinese versions of the following terms are as follows:

[0059] In the present invention, the term "matrix" refers to an inactive ingredient in a preparation, used to dilute or load the active ingredient, and the matrix can be a mixture of one or more substances.

[0060] In the present invention, the term "semisolid" has both solid and liquid properties, and can change shape and flow. The sustained-release layer described in the present invention is semisolid, and the liquid therein can be the solvent of the sustained-release layer solution prepared during the preparation of the sustained-release layer, or it can be the active ingredient A in liquid form. The active ingredient A is insoluble in a poor solvent for the hydrophobic polymer.

[0061] In the present invention, the term "poor solvent" refers to a solvent having a relatively weak dissolving ability for high molecular weight polymers.

[0062] As used herein, the term "active ingredient" refers to a substance used for diagnosis, treatment, prevention, cosmetics, medical aesthetics, or healthcare. According to the present invention, such active ingredients include, but are not limited to, pharmaceutical active ingredients, cosmetic active ingredients, health product active ingredients, and medical aesthetics active ingredients, and the specific active ingredients are selected based on actual needs.

[0063] In the present invention, the term "optionally includes" means that it may include or not include. For the microneedles of the present invention, the active ingredient contained in its structure is any one of the following options:

[0064] (1) Neither the sustained-release layer nor the immediate-release layer contains active ingredients, and the applications of microneedles include but are not limited to the field of medical aesthetics;

[0065] (2) The sustained-release layer contains at least one active ingredient, and the immediate-release layer does not contain an active ingredient;

[0066] (3) Both the sustained-release layer and the immediate-release layer contain at least one active ingredient, and the active ingredients contained in both are the same;

[0067] (4) Both the sustained-release layer and the immediate-release layer contain at least one active ingredient, and the active ingredients contained in the two are different.

[0068] In the present invention, the shape of the microneedle body is not limited and can be any shape, such as a cone, a triangular pyramid, a quadrangular pyramid, a pentagonal pyramid, a hexagonal pyramid, a heptagonal pyramid or an octagonal pyramid.

[0069] In the present invention, the term "not higher than" means ≤.

[0070] The present invention is further described in detail below by way of specific examples and in conjunction with the accompanying drawings. These examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. Unless otherwise specified, the materials and reagents used are all commercially available.

[0071] Example 1

[0072] Step 1: At room temperature, 0.4 g of PLGA (model: RG 502) and 0.01 g Sudan Red were dissolved in 0.6 g NMP and stirred for 3 h to form the sustained-release layer solution; 1 g hyaluronic acid (HYACARE 50, 50 kDa, purchased from Evonik Operations GmbH) and 0.6 g trehalose were dissolved in 8.4 g ultrapure water and stirred for 30 min to form the immediate-release layer solution;

[0073] Step 2: Take 50 μL of the sustained-release layer solution and cast it into the PDMS mold. Centrifuge it at 4000 rpm for 3-5 minutes, and carefully remove the excess sustained-release layer solution on the mold.

[0074] Step 3: Add 100 μL of ultrapure water to the sample from Step 2. Place the sample in a shaking incubator at room temperature and perform solvent exchange at 80 rpm / min for 1 hour. Carefully remove the exchange solution by aspiration. Repeat this step two more times.

[0075] Step 4: Take 100 μL of the immediate-release layer solution and cast it on the sample in step 3.

[0076] Step 5: Use an air pump to perform negative pressure vacuum drying on the PDMS mold, evacuate to -0.1 MPa, and vacuum dry for 8 hours.

[0077] Step 6: Dissolve 1.5 g of PVP in 8.5 g of anhydrous ethanol and stir overnight to prepare the base layer solution. Cast 100 μL of the base layer solution onto the sample obtained in step 5, dry at room temperature for 16 h, and demold.

[0078] Example 2

[0079] Step 1: At room temperature, 0.4 g of PLGA (model: RG 502) was dissolved in 0.6 g NMP and stirred for 3 h, 0.05 g freeze-dried HBsAg was added and stirred for 30 min to prepare the sustained-release layer solution; 1 g hyaluronic acid (HYACARE 50, 50 kDa, purchased from Evonik Operations GmbH) and 0.6 g trehalose were dissolved in 8.4 g ultrapure water containing 0.005 g HBsAg and stirred for 30 min to prepare the immediate-release layer solution;

[0080] Step 2: Take 50 μL of the sustained-release layer solution and cast it into the PDMS mold. Centrifuge it at 4000 rpm for 3-5 minutes, and carefully remove the excess sustained-release layer solution on the mold.

[0081] Step 3: Add 100 μL of ultrapure water to the sample from Step 2. Place the sample in a shaking incubator at room temperature and perform solvent exchange at 80 rpm / min for 1 hour. Carefully remove the exchange solution by aspiration. Repeat this step two more times.

[0082] Step 4: Take 100 μL of the immediate-release layer solution and cast it on the sample in step 3.

[0083] Step 5: Use an air pump to perform negative pressure vacuum drying on the PDMS mold, evacuate to -0.1 MPa, and vacuum dry for 8 hours.

[0084] Step 6: Dissolve 1.5 g of PVP in 8.5 g of anhydrous ethanol and stir overnight to prepare the base layer solution. Cast 100 μL of the base layer solution onto the sample obtained in step 5, dry at room temperature for 16 h, and demold.

[0085] Example 3

[0086] Step 1: At room temperature, 0.4 g of PLGA (model: RG 502) was dissolved in 0.6 g NMP and stirred for 3 h, 0.05 g freeze-dried HBsAg was added and stirred for 30 min to prepare the sustained-release layer solution; 1 g hyaluronic acid (HYACARE 50, 50 kDa, purchased from Evonik Operations GmbH) and 0.6 g trehalose were dissolved in 8.4 g ultrapure water containing 0.005 g HBsAg and stirred for 30 min to prepare the immediate-release layer solution;

[0087] Step 2: Take 50 μL of the sustained-release layer solution and cast it into the PDMS mold. Centrifuge it at 4000 rpm for 3-5 minutes, and carefully remove the excess sustained-release layer solution on the mold.

[0088] Step 3: Add 100 μL of ultrapure water to the sample from Step 2. Place the sample in a shaking incubator at room temperature and perform solvent exchange at 80 rpm / min for 1 hour. Carefully remove the exchange solution by aspiration. Repeat this step once more.

[0089] Step 4: Take 100 μL of the immediate-release layer solution and cast it on the sample in step 3.

[0090] Step 5: Use an air pump to perform negative pressure vacuum drying on the PDMS mold, evacuate to -0.1 MPa, and vacuum dry for 8 hours.

[0091] Step 6: Dissolve 1.5 g of PVP in 8.5 g of anhydrous ethanol and stir overnight to prepare the base layer solution. Cast 100 μL of the base layer solution onto the sample obtained in step 5, dry at room temperature for 16 h, and demold.

[0092] Example 4

[0093] Step 1: At room temperature, 0.4 g of PLGA (model: RG 502) was dissolved in 0.6 g NMP and stirred for 3 h, 0.05 g freeze-dried HBsAg was added and stirred for 30 min to prepare the sustained-release layer solution; 1 g hyaluronic acid (HYACARE 50, 50 kDa, purchased from Evonik Operations GmbH) and 0.6 g trehalose were dissolved in 8.4 g ultrapure water containing 0.005 g HBsAg and stirred for 30 min to prepare the immediate-release layer solution;

[0094] Step 2: Take 50 μL of the sustained-release layer solution and cast it into the PDMS mold. Centrifuge it at 4000 rpm for 3-5 minutes, and carefully remove the excess sustained-release layer solution on the mold.

[0095] Step 3: Add 100 μL of ultrapure water to the sample in step 2, place it in a shaking incubator at room temperature, and perform solvent exchange at 80 rpm / min for 1 hour. Carefully remove the exchange solution.

[0096] Step 4: Take 100 μL of the immediate-release layer solution and cast it on the sample in step 3.

[0097] Step 5: Use an air pump to perform negative pressure vacuum drying on the PDMS mold, evacuate to -0.1 MPa, and vacuum dry for 8 hours.

[0098] Step 6: Dissolve 1.5 g of PVP in 8.5 g of anhydrous ethanol and stir overnight to prepare the base layer solution. Cast 100 μL of the base layer solution onto the sample obtained in step 5, dry at room temperature for 16 h, and demold.

[0099] Comparative Example 1

[0100] Step 1: At room temperature, 0.4 g of PLGA (model: RG 502) was dissolved in 0.6 g of dichloromethane and stirred for 5 min to prepare the sustained-release layer solution.

[0101] Step 2: Take 50 μL of the sustained-release layer solution and cast it into the PDMS mold. Centrifuge it at 4000 rpm for 3-5 minutes, and carefully remove the excess sustained-release layer solution on the mold.

[0102] Step 3: Place the sample from step 2 in a fume hood at room temperature and allow the solvent to evaporate for 1 hour.

[0103] Step 4: Use an air pump to perform negative pressure vacuum drying on the PDMS mold, evacuate to -0.1Mpa, vacuum drying time is 8h, and demold.

[0104] The morphology and structure of microneedles

[0105] The morphology and structure of the microneedle patch obtained in Example 1 were observed using an optical microscope. As shown in Figures 2 and 3, the sustained-release layer inside the needle body contained Sudan Red, while the outer immediate-release layer did not contain any drug. The total length of the needle body was 750 μm, and the sustained-release layer was approximately 500 μm long. The results showed that the prepared microneedle patch had a double-layer structure, with the sustained-release layer located inside the immediate-release layer.

[0106] The microneedle patch obtained in Comparative Example 1 was immersed in water for 5 minutes, and its morphology and structure were observed using an optical microscope. As shown in Figure 4, after 5 minutes of dissolution in water, the back of the prepared patch was still adhered together in a grid-like manner, and no individual needle bodies could be formed.

[0107] In vitro skin insertion ability test of microneedle patches

[0108] The ability of the microneedle patch to penetrate the skin was assessed using pig abdominal skin. First, the pig abdominal skin was removed, hair removed, and fixed to a foam board. The microneedle patch obtained in Example 1 was applied to the skin, with thumb pressure applied for 2 minutes. The microneedles were then removed, and the skin was stained with trypan blue solution for 10 minutes. The skin surface was then wiped and cleaned with saline. The stained skin was photographed (Figure 5) and observed with a magnifying glass.

[0109] The results showed that the number of needle holes left on the skin after the microneedles were removed was exactly the same as the number of needle bodies on the microneedle patch, indicating that the microneedles were 100% inserted into the skin. The microneedles of the present invention have sufficient mechanical strength to pierce the stratum corneum of the skin.

[0110] Microneedle dissolution experiment in vitro

[0111] In vitro dissolution experiments of microneedles were conducted using pig abdominal skin: First, the pig abdominal skin was removed, the hair removed, and fixed to a foam board. The microneedle patch obtained in Example 1 was applied to the skin. After thumb pressure for different periods of time, the microneedles were removed and the changes in the needle morphology were observed under a microscope.

[0112] The results in Figure 6 show that the degree of dissolution of the quick-release layer of the microneedles of the present invention increases with the time of insertion into the skin. After 30 seconds of insertion, 30% of the total needle body has dissolved; after 1 minute of insertion, 58% of the total needle body has dissolved; after 3 minutes of insertion, 78% of the total needle body has dissolved; and after 10 minutes of insertion, 90% of the total needle body has dissolved.

[0113] In vitro drug release characteristics experiment of microneedles

[0114] The in vitro drug release profiles of the microneedle patches obtained in Examples 2, 3, and 4 were measured using a transdermal diffusion cell: The microneedle patches obtained in Examples 2, 3, and 4 were immersed in a 1.5 ml centrifuge tube containing 1 mL of PBS buffer (pH 7.4) and placed in a 37°C constant temperature shaker at 80 rpm. After shaking for 1, 3, 7, 14, 21, 28, 35, 42, 49, 56, 63, and 70 days, 0.5 mL of buffer was removed from the centrifuge tube and 0.5 mL of supplement solution was added. The HBsAg content in the PBS buffer dissolution medium at each time point was measured using a BCA assay kit, and the cumulative release was calculated.

[0115] The results in Figure 7 show that for the microneedle patch obtained in Example 2, a burst release of approximately 32% of the HBsAg loaded from the microneedles occurred at day 1; at day 35, the cumulative release reached approximately 42%; and at day 63, the cumulative release reached approximately 82%. The cumulative release of HBsAg increased at each time point as the number of solvent exchanges decreased.

[0116] Pharmacodynamics research on microneedles

[0117] Six-week-old female BALB / c mice were selected and housed under standard laboratory conditions. All animal studies were approved by the Institutional Animal Care and Use Committee.

[0118] The day before the experiment, the mice were depilated using a depilatory cream, and their backs were then cleaned with 70% (v / v) ethanol. The mice were then divided into two groups. The experimental group received microneedles (described in Example 2) applied to the depilated areas on their backs, followed by finger pressure for 10 minutes and then peeling. The control group received subcutaneous injections of the same dose of hepatitis B vaccine on days 0 and 14. Following administration, blood samples were collected from both groups every two weeks for eight weeks, and immunogenicity was measured using an ELISA kit.

[0119] As shown in Figure 8, the mice in the experimental group were able to produce earlier and stronger immune effects and maintain antigen activity for a long time.

[0120] The present invention uses a solvent exchange method to prepare microneedles, which has the following advantages over the solvent evaporation method commonly used in the prior art: First, the temperature conditions are mild, which can stabilize heat-sensitive drugs such as proteins; second, the residual solvent amount and the amount of polymer precipitation and solidification can be more flexibly and conveniently adjusted by the number of solvent exchanges, temperature, time, etc., thereby obtaining different states of sustained-release layers according to drug delivery needs and achieving different drug release effects; third, the base of the needle body does not adhere to each other, and each needle body can maintain an independent and good shape. The solvent evaporation method used in the prior art is difficult to control due to excessively fast solvent evaporation, and the bases of the resulting needle bodies adhere to each other, affecting drug efficacy; fourth, the solvent system used is safer and healthier for the human body.

[0121] It should be understood that the above-described embodiments are only preferred solutions of the present invention and do not limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solutions described in the claims.

Claims

1. A microneedle patch, comprising a base layer and a needle body, the needle body including an immediate-release layer and a sustained-release layer, characterized in that, The sustained-release layer is located inside the immediate-release layer, and the sustained-release layer is a semi-solid.

2. The microneedle patch according to claim 1, wherein the liquid content in the sustained-release layer is not higher than 40%; or the sustained-release layer comprises matrix A, and matrix A comprises a hydrophobic polymer; or the immediate-release layer comprises matrix B, and matrix B comprises a hydrophilic polymer.

3. The microneedle patch according to claim 2, wherein The hydrophobic polymer is one or more of polyglycolic acid, polylactic acid, poly(lactic-co-glycolic acid), polycaprolactone, polyanhydride, polyurethane, polyester amide, polyorthoester, poly(dioxanone), polyacetal, polyketal, polycarbonate, polyorthocarbonate, polyphosphazene, polyhydroxybutyrate, polyhydroxyvalerate, poly(alkylene oxalate), poly(alkylene succinate), and polymalic acid, preferably poly(lactic-co-glycolic acid) or polylactic acid; or The hydrophilic polymer is one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol and its derivatives, polyvinylpyrrolidone and its derivatives, hyaluronic acid and its derivatives, chondroitin sulfate, chitosan and its derivatives, maltose derivatives, and polyacrylamide derivatives, preferably hyaluronic acid and its derivatives.

4. The microneedle patch according to claim 3, wherein, The weight-average molecular weight of the poly(lactic-co-glycolic acid) is 2,000 to 100,000; the monomer ratio of lactic acid to glycolic acid in the poly(lactic-co-glycolic acid) is 50:50 to 100:0; or Matrix B further comprises a small molecule protectant, and the small molecule protectant is one or more of trehalose, glucose, fructose, starch, sucrose, glucose, maltose, lactose, lactulose, fructose, turanose, melezitose, panose, dextran, sorbitol, mannitol, and xylitol; or The sustained-release layer optionally comprises at least one active ingredient A, and the active ingredient A is selected from pharmaceutical active ingredients, cosmetic active ingredients, health care product active ingredients, or medical aesthetic active ingredients; preferably, the pharmaceutical active ingredient is hepatitis B virus surface antigen; or The immediate-release layer optionally comprises at least one active ingredient B, and the active ingredient B is selected from pharmaceutical active ingredients, cosmetic active ingredients, health care product active ingredients, or medical aesthetic active ingredients; preferably, the pharmaceutical active ingredient is hepatitis B virus surface antigen; or The base layer comprises a biocompatible polymer material, and the biocompatible polymer material is one or several of carboxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol and its derivatives, polyvinylpyrrolidone and its derivatives, sodium hyaluronate, chondroitin sulfate, dextran, silk fibroin, and gelatin; preferably, the biocompatible polymer material is polyvinylpyrrolidone; or The length of the needle body is 100 to 1,500 μm, the thickness of the base layer is 10 to 100 μm, and the density of the needle body is: there are 25 to 1,000 needle bodies on each square centimeter of the base layer.

5. A microneedle patch carrying hepatitis B virus surface antigen, comprising a base layer and a needle body, the needle body comprising a rapid release layer and a sustained release layer, characterized in that, The sustained-release layer is located inside the immediate-release layer. The sustained-release layer is semi-solid and comprises matrix A and hepatitis B surface antigen. Matrix A comprises poly(lactic-co-glycolic acid). The immediate-release layer comprises matrix B and hepatitis B surface antigen. Matrix B comprises hyaluronic acid.

6. A method for preparing a microneedle patch according to any one of claims 1 to 5, characterized in that, It includes the following steps: first prepare the sustained-release layer in a mold, and then prepare the immediate-release layer. The sustained-release layer is prepared by the solvent exchange method.

7. The preparation method according to claim 6, characterized in that, The method for preparing the needle body sustained-release layer includes the following steps: preparing a sustained-release layer solution containing a hydrophobic polymer, filling the mold with the sustained-release layer solution, and curing the sustained-release layer solution by the solvent exchange method; or The method for preparing the immediate-release layer includes the following steps: preparing an immediate-release layer solution containing a hydrophilic polymer, filling the mold after the sustained-release layer solution is cured with the immediate-release layer solution, and curing the immediate-release layer solution.

8. The preparation method according to claim 7, characterized in that, The solvent of the sustained-release layer solution is one or more of N-methylpyrrolidone, dimethyl sulfoxide, dimethylformamide, tetrahydrofuran, triethyl glycerol, benzyl benzoate, ethyl benzoate, triethanolamine, dioxane, polyethylene glycol, methoxypolyethylene glycol, alkoxypolyethylene glycol, polyethylene glycol ester, 2-pyrrolidone, dimethylacetamide, acetone, methyl acetate, and ethyl acetate, preferably N-methylpyrrolidone; or The hydrophobic polymer is one or more of polyglycolic acid, polylactic acid, poly(lactic-co-glycolic acid), polycaprolactone, polyanhydride, polyurethane, polyester amide, polyorthoester, poly(dioxanone), polyacetal, polyketal, polycarbonate, polyorthocarbonate, polyphosphazene, polyhydroxybutyrate, polyhydroxyvalerate, polyalkylene oxalate, polyalkylene succinate, and polymalic acid, preferably one of poly(lactic-co-glycolic acid) and polylactic acid; or The concentration of the hydrophobic polymer in the sustained-release layer solution is 0.1-80%, preferably 5-50%; or The solvent exchange method includes the following steps: adding a poor solvent of the hydrophobic polymer to the small holes of the mold filled with the sustained-release layer solution, and sucking out the exchanged solvent after solvent exchange for a period of time; or The temperature of the solvent exchange is 0-40°C, and the time is 5 min-24 h; or The step of filling the mold with the sustained-release layer solution includes centrifugation or negative pressure vacuum pumping; or The hydrophilic polymer is one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol and its derivatives, polyvinylpyrrolidone and its derivatives, hyaluronic acid and its derivatives, chondroitin sulfate, chitosan and its derivatives, maltose derivatives, and polyacrylamide derivatives, preferably hyaluronic acid and its derivatives; or The solvent of the immediate-release layer solution is water or a mixture of a polar solvent and water, preferably water; or The concentration of the hydrophilic polymer in the immediate-release layer solution is 0.1-80%, preferably 1-30%; or The step of filling the mold with the immediate-release layer solution includes centrifugation or negative pressure vacuum pumping; or The method for curing the immediate-release layer solution is drying and curing.

9. The preparation method according to claim 8, characterized in that, The step of solvent exchange is carried out in an orbital shaker incubator; or The poor solvents of the hydrophobic polymer are water, ethanol, and n-hexane, preferably water; or The weight-average molecular weight of the poly(lactic-co-glycolic acid) is 2,000 to 100,000; or The monomer ratio of lactic acid to glycolic acid in the poly(lactic-co-glycolic acid) is 50:50 to 100:

0.

10. Use of the microneedle patch according to any one of claims 1 to 5 in the preparation of a product for disease diagnosis, treatment, prevention, health care, medical aesthetics, and skin care.

Images