Microneedle Array Structure and Manufacturing Method thereof

Abstract

The present invention relates to a microneedle array structure that enables the quantification of an injected active substance and the control of its release rate, and a method for manufacturing the same. The microneedle array structure is made of a biodegradable polymer material and includes a hollow portion and a tip portion that closes one end of the hollow portion, thereby facilitating the accurate delivery of the active substance and the control of its release rate.

Description

Technology Field

[0001] The present invention relates to a microneedle array structure and a method for manufacturing the same, and more specifically, to a microneedle array structure capable of quantifying cargo material and controlling the release rate, and a method for manufacturing the same. Background Technology

[0003] Amid ongoing efforts in the beauty and medical technology fields to enhance the convenience of applying cosmetics and pharmaceuticals to subjects, 'microneedles,' a next-generation active ingredient delivery technology, have been garnering attention. Microneedles serve as an alternative to injectable or oral medications, producing the same effects as existing cosmetics or pharmaceuticals simply by being attached to the skin. In particular, the utilization of microneedles is increasing as there have recently been continuous attempts to integrate them into everyday applications aimed at improving quality of life, such as obesity drugs and hair loss treatments.

[0004] Microneedles typically refer to tiny needles measuring hundreds of nanometers, and a microneedle array is a transdermal delivery system consisting of a patch containing an assembly of multiple microneedles that is attached to the skin to deliver functional cosmetics and / or drugs into the skin. Because it utilizes numerous micro-needles attached to the skin to allow functional active substances to be absorbed into the body, it is referred to as a "patched injection" and has been primarily utilized in the fields of cosmetic or plastic surgery.

[0005] Microneedles come in various types and take on diverse forms, primarily depending on their intended use and manufacturing method. Solid microneedles are made from a single material and are mainly used to create micro-perforations at the application site, often involving the additional application of functional cosmetic compositions or drugs. They are typically manufactured using materials such as silicone, metal, and polymers. Coated microneedles are microneedles with a surface coated with a specific substance, used to deliver or detect specific substances to the skin. They are generally produced by manufacturing solid microneedles and then coating them with a specific material. Typically, the coating is made using biocompatible materials. Dissolving microneedles are microneedles that melt under specific conditions or over a specific period and are primarily used for the delivery of functional cosmetic compositions or drugs. As the microneedle body is inserted into the skin and melts, functional active substances are effectively delivered to the skin. Hollow microneedles are microneedles with a hollow center; they are primarily used to inject or extract liquids while inserted into the skin and have a form most similar to a typical syringe.

[0006] Microneedles can be utilized in various functional cosmetic ingredients and pharmaceuticals depending on the needle size, strength, and material. In particular, they offer the advantage of significantly less pain than conventional injections, leading to higher medication compliance and the prevention of infection accidents. Furthermore, because fine needles are used, excellent delivery of functional active substances can be expected even with small dosages, and the delivery speed of the active substances can also be controlled.

[0007] However, transdermal delivery of active substances using microneedles has disadvantages, such as the difficulty in achieving precise quantitative delivery and controlling the release rate. If the active substance cannot be quantified and delivered, a significant therapeutic effect may not occur, and if the release rate cannot be controlled, the duration of drug action may be shortened, resulting in insufficient sustained efficacy.

[0008] Therefore, there is a need to develop a microneedle array structure that enables quantitative drug delivery and control of release rates, as well as a method for manufacturing the same. Prior art literature

[0010] Specification of Republic of Korea Published Patent Application No. 10-2024-0036744 (March 21, 2024) The problem to be solved

[0011] The present invention aims to provide a microneedle array structure that enables the quantification of cargo materials and a method for manufacturing the same.

[0012] The present invention aims to provide a microneedle array structure that enables control of the release rate of a cargo material and a method for manufacturing the same.

[0013] The technical problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0015] 1. A method for manufacturing a microneedle array structure comprising: a step of filling a lower mold with a composition for manufacturing microneedles containing a polymer material; and a step of pressing an upper mold against the lower mold to form the composition into a microneedle shape including a hollow portion and a tip portion closing one end of the hollow portion.

[0016] 2. A method for manufacturing a microneedle array structure according to 1 above, wherein the lower mold comprises a plurality of microneedle-shaped grooves, and the upper mold comprises a plurality of protrusions formed with a length shorter than the depth of the grooves, and the grooves and the protrusions correspond to each other.

[0017] 3. A method for manufacturing a microneedle array structure, wherein, in addition to the above 1, the method further comprises the steps of: removing the upper mold and drying the molded composition to obtain a microneedle array structure; injecting a cargo material into the hollow portion of the microneedle; and separating the microneedle array structure into which the cargo material has been injected from the lower mold.

[0018] 4. A method for manufacturing a microneedle array structure according to 1, wherein the depth of the hollow portion is 10 μm to 990 μm and the thickness of the tip portion is 1 μm to 100 μm.

[0019] 5. A method for manufacturing a microneedle array structure according to 2 above, wherein the depth of the groove is 50 μm to 1000 μm and the length of the protrusion is 10 μm to 990 μm.

[0020] 6. A method for manufacturing a microneedle array structure, wherein the polymer material in 1 above is a biodegradable polymer material.

[0021] 7. In the above 6, the biodegradable polymer material is hyaluronic acid (HA), poly(lactic acid; PLA), poly(ε-caprolactone; PCL), polyhydroxyalkanoate (PHA), polyesteramide (PEA), polyethylene glycol (PEG), poly(p-dioxanone; PPDO), poly(lactic-co-glycolic acid; PLGA), polyglycolic acid (PGA), polyvinyl alcohol (PVA), chitosan, collagen, gelatin, alginic acid, pectin, carrageenan, chondroitin sulfate sulfate), dextran sulfate, polylysine, carboxymethyl chitin, fibrin, agarose, pullulan, cellulose, polyvinylpyrrolidone (PVP);Hydroxypropylcellulose (HPC), Hydroxyethylcellulose (HEC), Hydroxypropylmethylcellulose (HPMC), Carboxymethylcellulose, Arabic gum, Cyclodextrin, Dextrin, Glucose, Fructose, Starch, Trehalose, Glucosamine, Maltose, Lactose, Lactulose, Fructose, Turanose, Melitose, Melezitose, Dextran, Sorbitol, Xylitol, Palatinite, Polyglycolic acid, Polyethylene oxide, A method for manufacturing a microneedle array structure, wherein at least one is selected from the group consisting of polyacrylic acid, polyacrylamide, polymethacrylic acid, and polymaleic acid.

[0022] 8. A method for manufacturing a microneedle array structure according to 2 above, wherein the compression is performed after coating oil on the protrusion.

[0023] 9. A method for manufacturing a microneedle array structure, wherein, in the above 3, the separation is performed after forming a coating film that closes the other end of the hollow portion on the microneedle array structure into which the cargo material is injected.

[0024] 10. A method for manufacturing a microneedle array structure, wherein the drying is room temperature drying, vacuum drying, or hot air drying.

[0025] 11. A method for manufacturing a microneedle array structure, wherein the cargo material in accordance with 3 above is at least one selected from the group consisting of low molecular weight compounds, peptides, proteins, nucleic acids, polysaccharides, viruses, and liposomes.

[0026] 12. A microneedle array structure manufactured by the method of 1 above, comprising a plurality of microneedles formed by protruding in one direction, wherein the microneedles comprise a hollow portion and a tip portion closing one end of the hollow portion, and is made of a biodegradable polymer material.

[0027] 13. A microneedle array structure according to 12, further comprising a coating film made of the same biodegradable polymer material as the microneedle and closing the other end of the hollow portion.

[0028] 14. A microneedle array structure according to 12, wherein the hollow portion is filled with a cargo material for transdermal delivery. Effects of the invention

[0030] The microneedle array structure according to the present invention facilitates the quantification of cargo material and allows for the control of the release rate of cargo material by dissolving the tip of the microneedle first. Brief explanation of the drawing

[0032] FIG. 1 is a flowchart illustrating a method for manufacturing a microneedle array structure according to one embodiment of the present invention. FIG. 2 is a schematic diagram illustrating a method for manufacturing a microneedle array structure according to one embodiment of the present invention. FIG. 3 is a diagram schematically illustrating the entire process of a method for manufacturing a microneedle array structure according to one embodiment of the present invention. Figure 4 is a schematic diagram showing an upper mold and a lower mold filled with a composition for manufacturing microneedles. FIG. 5 is a side view illustrating the structure of an upper mold and a lower mold used in a method for manufacturing a microneedle array structure according to one embodiment of the present invention. FIG. 6 is a side view illustrating the structure of a microneedle array structure according to one embodiment of the present invention. FIG. 7 is an enlarged view of a microneedle of a microneedle array structure according to one embodiment of the present invention. FIG. 8 is a side view illustrating the structure of a microneedle array structure according to another embodiment of the present invention. Figure 9 is a schematic diagram showing the overall shape of a microneedle array structure. FIG. 10 is a drawing showing the dimensions (unit: mm) of a microneedle of a microneedle array structure according to one embodiment of the present invention. FIG. 11 is a drawing showing an upper mold including a microneedle-shaped protrusion. FIG. 12 is a drawing showing an upper mold including a microneedle-shaped protrusion. FIG. 13 is a drawing showing a lower mold including a microneedle-shaped groove. Figure 14 is a design drawing of the lower mold. Figure 15 is a design drawing of the lower mold. Specific details for implementing the invention

[0033] The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the claims. Throughout the specification, the same reference numerals refer to the same components.

[0034] Hereinafter, a method for manufacturing a microneedle array structure according to an embodiment of the present invention will be described in more detail with reference to FIGS. 1 to 3. FIG. 1 is a flowchart illustrating a method for manufacturing a microneedle array structure according to an embodiment of the present invention, and FIGS. 2 and 3 are drawings showing the manufacturing method in its entirety.

[0035] A method for manufacturing a microneedle array structure according to one embodiment of the present invention comprises the steps of: filling a lower mold with a composition for manufacturing microneedles containing a polymer material (S10); and pressing an upper mold against the lower mold to form the polymer material into a microneedle shape including a hollow portion and a tip portion closing one end of the hollow portion (S20).

[0036] The hollow part is contained within the body of the microneedle and can carry an active substance, such as a drug, as a cargo material.

[0037] The tip acts as a tip that closes one end of the hollow portion, perforates the skin, and by dissolving first, enables transdermal delivery of the cargo material carried in the hollow portion.

[0038] FIG. 4 briefly illustrates an upper mold and a lower mold used in a method for manufacturing a microneedle array structure according to one embodiment of the present invention, and FIG. 5 is a side view illustrating the structure of the upper mold and the lower mold.

[0039] The lower mold (10) includes a plurality of microneedle-shaped grooves (11), and the upper mold (20) includes a plurality of protrusions (21) formed with a length shorter than the depth (h1) of the grooves (11), and the grooves (11) and the protrusions (21) may each correspond to each other.

[0040] The lower mold (10) may be a mold, and the depth (h1) of the microneedle-shaped groove (11) included in the lower mold (10) may be set according to the height (h) of the microneedle (110) to be manufactured. The depth (h1) of the microneedle-shaped groove (11) may be varied, for example, from 50 μm to 1000 μm, from 50 μm to 900 μm, from 50 μm to 800 μm, from 50 μm to 700 μm, from 50 μm to 600 μm, from 100 μm to 600 μm, from 200 μm to 600 μm, from 300 μm to 600 μm, and from 400 μm to 600 μm, and preferably may be 500 μm.

[0041] The microneedle-shaped groove (11) included in the lower mold (10) may be conical, polygonal pyramidal, or bell tower shaped. A lower mold (10) including a conical microneedle-shaped groove (11) is exemplarily shown in FIG. 13, and a design drawing of an exemplary lower mold (10) is shown in FIG. 14 and FIG. 15.

[0042] The upper mold (20) may be a mold, and the length (h2) of the protrusion (21) included in the upper mold (20) may be adjusted according to the depth (hh) of the hollow portion (112) to be formed. The length (h2) of the protrusion (21) included in the upper mold (20) may be, for example, 10 μm to 990 μm, 10 μm to 900 μm, 10 μm to 900 μm, 10 μm to 900 μm, 10 μm to 800 μm, 10 μm to 700 μm, 10 μm to 600 μm, 10 μm to 500 μm, 10 μm to 400 μm, 50 μm to 400 μm, or 100 μm to 400 μm.

[0043] The protrusion (21) included in the upper mold (20) may be in the shape of a capillary tube, a cone, a polygonal pyramid, or a bell tower similar to a microneedle, a cylinder, or a polygonal prism such as a triangular prism, a square prism, a hexagonal prism, or an octagonal prism, and is not limited thereto as long as it is in a shape capable of forming a hollow portion capable of holding cargo material. An upper mold (20) in which the protrusion (21) is in the shape of a microneedle is exemplarily shown in FIGS. 11 and 12.

[0044] Since the length (h2) of the protrusion (21) of the upper mold (20) is formed to be shorter than the depth (h1) of the groove (11) of the lower mold (10), when a polymer material is filled into the lower mold (10) and the upper mold (20) is pressed over it, the polymer material is formed into a microneedle shape having a hollow portion (112) with one end closed.

[0045] A manufacturing method according to one embodiment of the present invention may further include the step of obtaining a microneedle array structure by removing an upper mold and drying a molded composition (S30); the step of injecting a cargo material into the hollow portion of the microneedle (S40); and the step of separating the microneedle array structure into which the cargo material has been injected from the lower mold (S50).

[0046] In a manufacturing method according to one embodiment of the present invention, drying may be room temperature drying, vacuum drying, or hot air drying. By drying, a composition for manufacturing microneedles containing a polymer material can be hardened.

[0047] In a manufacturing method according to one embodiment of the present invention, a composition for manufacturing microneedles containing a polymer material can be easily molded by compressing the upper mold (20), and after curing, it can have a hardness capable of puncturing the skin.

[0048] In a manufacturing method according to one embodiment of the present invention, the polymer material is a biodegradable polymer material and may be a biocompatible biodegradable polymer material.

[0049] "Biocompatibility" refers to the property of being practically non-toxic to the human body, chemically inert, and non-immunogenic.

[0050] "Biodegradability" refers to the characteristic of self-decomposing within the human body in response to environmental factors such as temperature, moisture, and microorganisms.

[0051] In a manufacturing method according to one embodiment of the present invention, the biodegradable polymer material is, for example, hyaluronic acid (HA), poly(lactic acid; PLA), poly(ε-caprolactone; PCL), polyhydroxyalkanoate (PHA), polyesteramide (PEA), polyethylene glycol (PEG), poly(p-dioxanone; PPDO), poly(lactic-co-glycolic acid; PLGA), polyglycolic acid (PGA), polyvinyl alcohol (PVA), chitosan, collagen, gelatin, alginic acid, pectin, carrageenan, Chondroitin sulfate, dextran sulfate, polylysine, carboxymethyl chitin, fibrin, agarose, pullulan, cellulose, polyvinylpyrrolidone (PVP);Hydroxypropylcellulose (HPC), Hydroxyethylcellulose (HEC), Hydroxypropylmethylcellulose (HPMC), Carboxymethylcellulose, Arabic gum, Cyclodextrin, Dextrin, Glucose, Fructose, Starch, Trehalose, Glucosamine, Maltose, Lactose, Lactulose, Fructose, Turanose, Melitose, Melezitose, Dextran, Sorbitol, Xylitol, Palatinite, Polyglycolic acid, Polyethylene oxide, It may be at least one selected from the group consisting of polyacrylic acid, polyacrylamide, polymethacrylic acid, and polymaleic acid.

[0052] In a manufacturing method according to one embodiment of the present invention, the biodegradable polymer material may be hyaluronic acid.

[0053] In a manufacturing method according to one embodiment of the present invention, the average molecular weight of the biodegradable polymer material may be 100,000 Da to 5,000,000 Da, 100,000 Da to 4,000,000 Da, 100,000 Da to 3,000,000 Da, 200,000 Da to 3,000,000 Da, 300,000 Da to 3,000,000 Da, 500,000 Da to 3,000,000 Da, 1,000,000 Da to 3,000,000 Da, or 1,000,000 Da to 200,000 Da.

[0054] In a manufacturing method according to one embodiment of the present invention, the composition for manufacturing microneedles may use purified water as a solvent, and the final concentration of the biodegradable polymer material may be 0.5 to 20 wt%, 0.5 to 20 wt%, 0.5 to 15 wt%, 0.5 to 10 wt%, or 0.5 to 8 wt%.

[0055] In a manufacturing method according to one embodiment of the present invention, the composition for manufacturing microneedles may be prepared using purified water as a solvent such that the final concentration of sodium hyaluronate with a molecular weight of 100,000 to 300,000 Da is 1.2 to 20 weight%.

[0056] In a manufacturing method according to one embodiment of the present invention, the composition for manufacturing microneedles may be prepared using purified water as a solvent such that the final concentration of sodium hyaluronate with a molecular weight of 500,000 to 1,500,000 Da is 1 to 10 weight%.

[0057] In a manufacturing method according to one embodiment of the present invention, the composition for manufacturing microneedles may be prepared using purified water as a solvent such that the final concentration of sodium hyaluronate with a molecular weight of 1.5 million to 2.5 million Da is 0.5 to 8 weight%.

[0058] In a manufacturing method according to one embodiment of the present invention, the compression may be performed after coating oil on the protrusion (21).

[0059] When oil is coated on the protrusion (21) of the upper mold (20) and then compressed, the interior of the microneedle hollow formed by the protrusion (21) can be coated with oil. When the interior of the hollow is coated with oil, a hydrophilic cargo material can be stably injected into the hollow. In this case, moisture resistance is improved, and the stability of the cargo material can be increased. However, if the cargo material is hydrophobic, the process of coating the interior of the hollow with oil may not necessarily be required.

[0060] In a manufacturing method according to one embodiment of the present invention, separation from the lower mold may be performed after forming a coating film that closes the other end of the hollow portion on a microneedle array structure into which a cargo material has been injected.

[0061] The other end of the hollow section refers to the open end opposite the end that is closed at the tip, and corresponds to the part adjacent to the base layer.

[0062] The coating film can be formed by closing the other end of the hollow portion and coming into contact with one side of the base layer.

[0063] The term “cargo substance” refers to a substance intended to be delivered into the skin of a subject, and is a biocompatible substance suitable for ingestion, meaning an active substance expected to produce the desired effect for the user, and is not specifically limited.

[0064] The cargo material may be at least one selected from the group consisting of, for example, small molecule compounds, peptides, proteins, nucleic acids, polysaccharides, viruses, and liposomes. Nucleic acids may include oligonucleotides, plasmid DNA, siRNA, PNAs (peptide nucleic acids), etc.

[0065] The cargo material can be selected without limitation from, for example, conventionally known pharmaceutical compositions or functional cosmetic compositions.

[0066] The cargo substance may be, for example, an active substance known to have antioxidant, anti-inflammatory, or anti-allergic effects, or an effective mixture thereof; it may be an active substance having efficacy such as skin whitening, wrinkle improvement, UV protection, or acne relief; and it may be a drug that can be used to treat various diseases, including anticancer agents.

[0067] The cargo substance may be a drug that can be effectively administered in a subcutaneous injection form. For example, it may be a certain disease prevention vaccine, insulin, heparin, opioid, epinephrine, or anti-allergic drug.

[0068] The present invention provides a microneedle array structure manufactured by a manufacturing method according to one embodiment of the present invention.

[0069] FIG. 6 is a side view illustrating the structure of a microneedle array structure according to one embodiment of the present invention, and FIG. 7 is an enlarged view of a microneedle of a microneedle array structure according to one embodiment of the present invention.

[0070] A microneedle array structure (100) according to one embodiment of the present invention may include microneedles (110) and a base layer (120).

[0071] A microneedle array structure (100) according to one embodiment of the present invention comprises a plurality of microneedles (110) formed by protruding in one direction, and the microneedle (110) comprises a hollow portion (112) and a tip portion (111) that closes one end of the hollow portion (112), and may be made of a biodegradable polymer material.

[0072] A microneedle array structure (100) according to one embodiment of the present invention may have a cargo material for transdermal delivery filled in a hollow portion (112).

[0073] A microneedle array structure (100) according to one embodiment of the present invention is made of a composition for manufacturing microneedles containing a biodegradable polymer material and includes a hollow portion (112) and a tip portion (111) that closes one end of the hollow portion. In the microneedle array structure (100) according to one embodiment of the present invention, the dissolution of the tip portion (111) that first penetrates the skin occurs first, thereby enabling the accurate delivery of a cargo material contained in the hollow portion (112).

[0074] The hollow portion (112) is contained within the body of the microneedle (110), and an active substance such as a drug can be filled into the hollow portion (112) as a cargo material. The shape of the hollow portion (112) can be formed according to the shape of the protrusion (21) of the upper mold (20), and, for example, may be a shape similar to a capillary shape, a cone shape, a polygonal pyramid shape, or a bell tower shape, a cylindrical shape, or a polygonal prism shape such as a triangular prism, a square prism, a hexagonal prism, or an octagonal prism.

[0075] The overall shape of the microneedle (110) filled with cargo material in the hollow portion (112) is exemplarily shown in FIG. 9.

[0076] The depth (hh) of the hollow portion (112) is set shorter than the height (h) of the microneedle (110), and may be, for example, 10 μm to 990 μm, 10 μm to 900 μm, 10 μm to 800 μm, 10 μm to 700 μm, 10 μm to 600 μm, 10 μm to 500 μm, 10 μm to 400 μm, 50 μm to 400 μm, or 100 μm to 400 μm.

[0077] By adjusting the depth (hh) of the hollow portion (112), the amount of cargo material filled into the hollow portion (112) can be varied.

[0078] The tip (111) is a tip that closes one end of the hollow portion (112), and after perforating the skin, it dissolves to enable transdermal delivery of the cargo material filled in the hollow portion (112).

[0079] The tip (111) can be inserted into the subcutaneous fat or dermis layer of the skin, and can cause the cargo material filled in the hollow part (112) to be released by dissolving in the subcutaneous fat or dermis layer.

[0080] The thickness (ht) of the tip portion (111) can be determined according to the difference between the depth (hh) of the hollow portion (112) and the height (h) of the microneedle (110), for example, it can be 1 μm to 300 μm, 1 μm to 250 μm, 1 μm to 200 μm, 1 μm to 150 μm, or 1 μm to 100 μm.

[0081] By adjusting the thickness (ht) of the tip portion (111), the rate at which the tip portion (111) dissolves can be varied, and by adjusting the rate at which the tip portion (111) dissolves, the time at which the release of the drug contained in the hollow portion (112) begins can be adjusted.

[0082] In a microneedle array structure (100) according to one embodiment of the present invention, microneedles (110) may be arranged on a base layer (120) in a predetermined size, shape, and spacing according to the purpose and use. For example, they may be arranged in a size and spacing as shown in FIG. 10.

[0083] In a microneedle array structure (100) according to one embodiment of the present invention, the height (h) of the microneedle (110) and the diameter (dm) of the bottom surface may have a length ratio of 1:5 to 3:1, 1:4 to 3:1, 1:3 to 3:1, 1:2 to 3:1, 1:1 to 3:1, 1:1 to 2.5:1, or 1:1 to 2:1. The diameter (dm) of the bottom surface of the microneedle (110) described above refers to the maximum diameter of the bottom surface of the microneedle. For example, if the shape of the bottom surface of the microneedle (110) is an equilateral triangle, the length of one side becomes the maximum diameter; if it is a circle, the length of the diameter becomes the maximum diameter; if it is a regular polygon with an even number of vertices, the length from one vertex to the vertex opposite it becomes the maximum diameter; and if it is a regular polygon with an odd number of vertices, the length from one vertex to either of the two vertices of the side opposite it becomes the maximum diameter.

[0084] In a microneedle array structure (100) according to one embodiment of the present invention, the height (h) of the microneedle (110) may be 50 μm to 1000 μm. The height (h) of the microneedle (110) may be adjusted in various ways by various factors such as the application site on the skin, the depth to which an active substance is to be delivered, or changes in the intensity of the microneedle (110) due to changes in raw materials, for example, the height (h) of the microneedle (110) may be adjusted in various ways such as 50 μm to 900 μm, 50 μm to 800 μm, 50 μm to 700 μm, 50 μm to 600 μm, 100 μm to 600 μm, 200 μm to 600 μm, 300 μm to 600 μm, 400 μm to 600 μm, and preferably 500 μm.

[0085] In a microneedle array structure (100) according to one embodiment of the present invention, the diameter (dm) of the bottom surface of the microneedle (110) may be appropriately selected by a person skilled in the art in relation to the height (h) of the microneedle (110) so as to form a minimum tip angle (111) of the microneedle (110) capable of penetrating the skin. Specifically, for example, the diameter (dm) of the bottom surface of the microneedle (110) may be 50 μm to 5000 μm. In another embodiment, the diameter (dm) is 50 μm to 4500 μm, 50 μm to 4000 μm, 50 μm to 3500 μm, 50 μm to 3000 μm, 50 μm to 2500 μm, 50 μm to 2000 μm, 50 μm to 1500 μm, 50 μm to 1400 μm, 50 μm to 1300 μm, 50 μm to 1200 μm, 50 μm to 1100 μm, 50 μm to 1000 μm, 50 μm to 900 μm, 50 μm to 800 μm, 50 μm to 700 μm, 50 μm to 600 μm, 50 μm to 500 μm, It can be varied to 50 μm to 400 μm, 100 μm to 400 μm, or 200 μm to 400 μm, and preferably 300 μm.

[0086] In a microneedle array structure (100) according to one embodiment of the present invention, the spacing between microneedles (110) can be varied from 1000 μm to 2000 μm, 1000 μm to 1900 μm, 1000 μm to 1800 μm, 1000 μm to 1700 μm, 1000 μm to 1600 μm, 1000 μm to 1500 μm, 1000 μm to 1400 μm, and 1000 μm to 1300 μm, and preferably 1200 μm.

[0087] In a microneedle array structure (100) according to one embodiment of the present invention, the microneedle (110) may be conical, polygonal pyramidal, or bell tower-shaped, and the polygonal pyramidal shape includes various polygonal pyramidal shapes including triangular pyramids, square pyramids, hexagonal pyramids, octagonal pyramids, and dodecagonal pyramids. The shape of the microneedle (110) is not limited thereto as long as it is a shape capable of piercing and penetrating the skin.

[0088] FIG. 8 is a side view illustrating the structure of a microneedle array structure (100) according to another embodiment of the present invention.

[0089] A microneedle array structure (100) according to another embodiment of the present invention may further include a coating film (130) that is made of the same biodegradable polymer material as the microneedle (110) and closes the other end of the hollow portion (112).

[0090] The coating film (130) can be formed by closing the other end of the hollow portion (112) and contacting one side of the base layer (120).

[0091] The coating film (130) serves as a support for the microneedle array structure (100) and can be formed of the same material as the polymer material that makes up the microneedle (110).

[0092] If the coating film (130) is formed of the same material as the polymer material forming the microneedles (110), then after applying the microneedle array structure (100) to the skin of a subject for transdermal delivery, the process of removing the coating film (130) is not required.

[0094] Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention may be implemented in other specific forms without changing its technical concept or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. Explanation of the symbols

[0096] 10: Lower mold 11: Groove 20: Upper mold 21: Protrusion 100: Microneedle array structure 110: Microneedle 111: High-tech Division 112: China Division 120: Base layer 130: Coating film h1: Groove depth h2: Protrusion length h: Microneedle height ht: Tip thickness hh: Hollow depth dm: Diameter of the microneedle base

Claims

Claim 1 A method for manufacturing a microneedle array structure comprising: a step of filling a lower mold containing a plurality of grooves in the shape of a microneedle with a composition for manufacturing a microneedle containing a polymer material; a step of pressing an upper mold, which includes a plurality of protrusions formed with a length shorter than the depth of the grooves and corresponding to each of the grooves, against the lower mold to form the composition into a microneedle shape including a hollow portion and a tip portion closing one end of the hollow portion; a step of drying the formed composition to obtain a microneedle array structure; a step of injecting a cargo material into the hollow portion of the microneedle; and a step of separating the microneedle array structure into which the cargo material has been injected from the lower mold; wherein, when pressing the upper mold against the lower mold, the plurality of protrusions are coated with oil before pressing, so that the interior of the hollow portion of the microneedle is coated with oil. Claim 2 A method for manufacturing a microneedle array structure according to claim 1, wherein the cargo material is a hydrophilic material. Claim 3 delete Claim 4 A method for manufacturing a microneedle array structure according to claim 1, wherein the depth of the hollow portion is 10 μm to 990 μm and the thickness of the tip portion is 1 μm to 100 μm. Claim 5 A method for manufacturing a microneedle array structure according to claim 1, wherein the depth of the groove is 50 μm to 1000 μm and the length of the protrusion is 10 μm to 990 μm. Claim 6 A method for manufacturing a microneedle array structure according to claim 1, wherein the polymer material is a biodegradable polymer material. Claim 7 In claim 6, the biodegradable polymer material is hyaluronic acid (HA), poly(lactic acid; PLA), poly(ε-caprolactone; PCL), polyhydroxyalkanoate (PHA), polyesteramide (PEA), polyethylene glycol (PEG), poly(p-dioxanone; PPDO), poly(lactic-co-glycolic acid; PLGA), polyglycolic acid (PGA), polyvinyl alcohol (PVA), chitosan, collagen, gelatin, alginic acid, pectin, carrageenan, chondroitin sulfate sulfate), dextran sulfate, polylysine, carboxymethyl chitin, fibrin, agarose, pullulan, cellulose, polyvinylpyrrolidone (PVP);Hydroxypropylcellulose (HPC), Hydroxyethylcellulose (HEC), Hydroxypropylmethylcellulose (HPMC), Carboxymethylcellulose, Arabic gum, Cyclodextrin, Dextrin, Glucose, Fructose, Starch, Trehalose, Glucosamine, Maltose, Lactose, Lactulose, Fructose, Turanose, Melitose, Melezitose, Dextran, Sorbitol, Xylitol, Palatinite, Polyglycolic acid, Polyethylene oxide, A method for manufacturing a microneedle array structure, wherein at least one is selected from the group consisting of polyacrylic acid, polyacrylamide, polymethacrylic acid, and polymaleic acid. Claim 8 delete Claim 9 A method for manufacturing a microneedle array structure according to claim 1, wherein the separation is performed after forming a coating film that closes the other end of the hollow portion on the microneedle array structure into which the cargo material is injected. Claim 10 A method for manufacturing a microneedle array structure according to claim 1, wherein the drying is room temperature drying, vacuum drying, or hot air drying. Claim 11 A method for manufacturing a microneedle array structure according to claim 1, wherein the cargo material is at least one selected from the group consisting of low molecular weight compounds, peptides, proteins, nucleic acids, polysaccharides, viruses, and liposomes. Claim 12 delete Claim 13 delete Claim 14 delete

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