Assembly-type microneedle mold and microneedle manufacturing method using same

Abstract

The present disclosure relates to an assembly-type microneedle mold and a microneedle manufacturing method using same, the assembly-type microneedle mold comprising: a mold plate including a microneedle shape protruding upward; and a plurality of discrete microneedle pins, wherein the mold plate includes a plurality of slots into which needle portions of the microneedle pins can be inserted. Specifically, the present disclosure relates to an assembly-type microneedle mold capable of manufacturing various molds by freely combining microneedle tips having various sizes and lengths on a mold plate.

Description

Assembly type microneedle mold and method for manufacturing microneedles using the same

[0001] The present disclosure relates to an assembly type microneedle mold and a method for manufacturing microneedles using the same.

[0002] The current global microneedle market is worth approximately 1.5895 trillion won and is steadily increasing. Microneedles are a technology that uses tiny needles, hundreds of micrometers in length, to penetrate the stratum corneum of the skin and reach the epidermis and dermis layers to deliver drugs painlessly, or to create bioelectrodes with superior performance compared to surface electrodes.

[0003] However, existing microneedle manufacturing methods primarily involve mass production using molds of fixed shapes. This traditional mold manufacturing method has the following problems.

[0004] First, the cost of manufacturing molds is very high, and this cost increases even further, especially when producing microneedle tips with complex shapes. Second, since molds must be reused once manufactured, it is difficult to change or improve the design of microneedles; therefore, new molds must be manufactured to produce new types of microneedles. This results in additional time and costs being consumed in the process of modifying molds or manufacturing additional molds.

[0005] Furthermore, as the demand for microneedles with various shapes and functions increases, there is a growing need for flexible production systems capable of manufacturing microneedles in diverse ways. Particularly in the medical and biomedical fields, the shapes and functions of microneedles required vary, necessitating technical solutions capable of producing various types of microneedles to meet these demands. However, existing mold systems have the disadvantage of requiring the continuous production of new molds to satisfy these requirements, which entails significant costs and time consumption. While 3D printing technology has been proposed as an alternative, current commercial 3D printers are unsuitable for the precise fabrication of microneedle tips due to limitations in resolution and durability. These technical limitations are acting as a significant factor hindering the growth of the microneedle industry.

[0006] The present disclosure is devised to solve the above-mentioned problems, and according to one aspect of the present disclosure, it provides an assembly type microneedle mold capable of assembling various shapes by arranging and assembling microneedle pins on a plate, and a method for manufacturing microneedles using the same.

[0007] The present disclosure provides an assembly type microneedle mold (30) comprising: a mold plate (1) having a microneedle base shape protruding in an upward direction; and a plurality of separated microneedle pins (2); wherein the mold plate (1) includes a plurality of slots into which the needle portions of the microneedle pins (2) can be inserted, and the microneedle pins (2) are detachably attached to the mold plate (1).

[0008] In one embodiment of the present disclosure, the mold plate (1) may include a plurality of slots ranging from 1 (1x1) to 900 (30x30) arranged regularly per unit area (1cm x 1cm).

[0009] In one embodiment of the present disclosure, the microneedle pin (2) may include a pillar portion; and a microneedle needle portion.

[0010] In one embodiment of the present disclosure, the height of the micro-needle needle portion may be 100 μm to 3,000 μm.

[0011] In one embodiment of the present disclosure, the aspect ratio of the microneedle needle portion may be in the range of 1:1 to 1:20.

[0012] In one embodiment of the present disclosure, the angle of the tip of the needle portion of the microneedle pin (2) may be 30° or more.

[0013] In one embodiment of the present disclosure, the microneedle needle portion may have a tip selected from the group consisting of a cone, a triangular pyramid, a square pyramid, a pentagonal pyramid, a hexagonal pyramid, and a polygonal pyramid.

[0014] In one embodiment of the present disclosure, a method for manufacturing a microneedle intaglio mold can be provided, comprising: a step of preparing a first mold by assembling microneedle pins (2) on a mold plate (1) using the aforementioned assembly type microneedle mold (30); and a step of forming a microneedle mold having the same intaglio shape as the first mold using a first polymer material.

[0015] In one embodiment of the present disclosure, a first mold may be formed by assembling microneedle pins (2), each having the same length and size of the tip portion, onto a mold plate (1).

[0016] In one embodiment of the present disclosure, one or more types of microneedle pins (2) with different lengths and sizes of tip portions may be assembled on a mold plate (1) to form a first mold.

[0017] In one embodiment of the present disclosure, a primary mold may be formed by attaching a microneedle tip in a slanted multi-array shape to a mold plate (1).

[0018] In one embodiment of the present disclosure, the first polymer material may be one or more selected from the group consisting of silicone-based polymers or polyurethanes.

[0019] In one embodiment of the present disclosure, a microneedle intaglio mold (40) manufactured according to the microneedle manufacturing method described above may be provided.

[0020] In another embodiment of the present disclosure, a method for manufacturing microneedles is provided, comprising: a step of preparing the aforementioned microneedle intaglio mold (40); a step of injecting a second polymer material into the microneedle intaglio mold (40); a vacuum placement step in which the mold into which the second polymer material has been injected is placed in a vacuum; a microneedle array curing step in which the second polymer material injected into the microneedle mold placed in the vacuum is cured; and a step of separating the cured microneedle array.

[0021] In one embodiment of the present disclosure, the second polymer material may be selected from the group consisting of a polymer solution in which an active ingredient for therapeutic purposes is dissolved in a biocompatible polymer, a polyimide polymer, and a shape memory polymer.

[0022] In one embodiment of the present disclosure, the step of forming a conductive layer by coating a metal electrode or a conductive polymer on the surface of the separated microneedles may be further included.

[0023] The present disclosure also provides a method for manufacturing hollow microneedles comprising: a step of preparing the aforementioned microneedle intaglio mold; a step of injecting a second polymer material into the microneedle intaglio mold; a step of inserting a hollow-generating needle along the central axis of each microneedle formation position of the intaglio mold through a needle jig while the second polymer material is injected; a vacuum placement step of placing the needle jig and the intaglio mold into which the second polymer material is injected into a vacuum while the hollow-generating needle is inserted; a microneedle array curing step of curing the second polymer material injected into the microneedle intaglio mold in the vacuum state; a step of removing the needle jig after the curing is completed, and then separating the microneedle array into which the hollow-generating needle is inserted from the intaglio mold; and a step of removing the hollow-generating needle from the microneedle array.

[0024] According to one embodiment of the present disclosure, an assembled microneedle mold (30) can produce multiple primary molds by assembling microneedle pins (2) of a design having a desired size or shape onto a mold plate (1) as needed.

[0025] An assembled microneedle mold (30) according to one embodiment of the present disclosure can provide a microneedle mold including a sharp microneedle tip than performing a conventional 3D process.

[0026] A manufacturing method using an assembly type microneedle mold (30) according to one embodiment of the present disclosure can provide the effect of manufacturing microneedles having a complex shape in a short time and at low cost.

[0027] A manufacturing method using an assembly type microneedle mold (30) according to one embodiment of the present disclosure can improve skin penetration ability by making the microneedle tip sharp.

[0028] Figure 1 shows the upper side view (a) and the rear side view (b) of an assembled microneedle mold plate.

[0029] FIG. 2 illustrates the column portion (22) and needle portion (21) of a microneedle pin.

[0030] Figure 3 illustrates an A-type microneedle pin of one embodiment.

[0031] Figure 4 illustrates a B-type microneedle pin of one embodiment.

[0032] Figure 5 illustrates a C-type microneedle pin of one embodiment.

[0033] Figure 6 illustrates a D-type microneedle pin of one embodiment.

[0034] FIG. 7 shows an upper side view (a) and a lower side view (b) of a plate with microneedle pins attached to the back surface of one embodiment.

[0035] Figure 8 illustrates a schematic diagram of an inclined microneedle with microneedle pins of different lengths and sizes attached to a plate.

[0036] Figure 9 is a schematic diagram showing microneedle pins arranged on a plate.

[0037] Figure 10 illustrates a side view of microneedle pins of different lengths and sizes attached to a plate.

[0038] FIG. 11 illustrates a microneedle manufactured using the assembled microneedle mold of the present disclosure.

[0039] FIG. 12 is a schematic diagram illustrating a method for manufacturing hollow microneedles according to the present disclosure.

[0040] FIG. 13 is a schematic diagram of an intaglio mold containing various types of hollow microneedles.

[0041] FIG. 14 is a schematic cross-sectional view illustrating a structure in which a hollow-generating needle (55) is aligned and fixedly inserted at a hollow microneedle formation location while a hollow microneedle jig is applied, according to one embodiment of the present disclosure.

[0042] The advantages and features of the present disclosure and the methods for achieving them will become clear by referring to the embodiments described in detail below. However, the present disclosure 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 disclosure is complete and to fully inform those skilled in the art of the scope of the invention, and the present disclosure is defined only by the scope of the claims.

[0043] Unless otherwise defined, all terms used in this specification (including technical and scientific terms) may be used in a meaning that is commonly understood by those skilled in the art to which this disclosure pertains.

[0044] Unless otherwise specifically indicated, the singular form of a term used in this specification may be interpreted to include the plural form.

[0045] The numerical ranges used herein include lower and upper limits and all values ​​within the range, increments logically derived from the form and width of the defined range, all of which are limited values, and all possible combinations of upper and lower limits of the numerical range defined in different forms. Unless otherwise specifically defined in the specification of this disclosure, values ​​outside the numerical range that may occur due to experimental error or rounding of values ​​are also included in the defined numerical range.

[0046] As used in this specification, "comprising" is an open description equivalent to expressions such as "comprising," "containing," "having," and "characteristics," and does not exclude elements, materials, or processes not additionally listed.

[0047] As mentioned in this specification, 'tip diameter' refers to the longest side of the cross-section of the insertion end, but may refer to the diameter if the cross-section is circular,

[0048] As mentioned in this specification, the 'tip' of a microneedle refers to the outermost portion of the leading edge that first contacts the skin when the microneedle is applied to the skin. Alternatively, it refers to a portion of the same shape of an assembled microneedle mold for forming it.

[0049] The 'aspect ratio' mentioned in this specification refers to the ratio of the height to the base of the needle portion of the microneedle pin (2).

[0050] The 'base' mentioned in this specification can be verified by measuring the length of the base of the needle portion of the microneedle pin (2).

[0051] The terms "hollow microneedle jig (50)" or "hollow needle jig (50)" as mentioned in this specification refer to an auxiliary structure that aligns and fixes a hollow-forming needle (55) to a microneedle intaglio mold (40) or a microneedle formation location, thereby stably maintaining the insertion position, insertion depth, and direction of the needle during the curing process. The hollow microneedle jig (50) may include a needle jig (51) and a mold jig (52).

[0052] The term 'microneedle array' as used in this specification refers to a structure in which a plurality of microneedles are arranged on a substrate, formed by curing a second polymer material injected into a microneedle intaglio mold (40).

[0053] Hereinafter, the assembly type microneedle mold of the present disclosure and the method for manufacturing microneedles using the same will be described in detail. However, this is merely illustrative and the present disclosure is not limited to the specific embodiments described illustratively.

[0054] Conventional microneedle molds have the disadvantage that they cannot be modified once produced and consume a lot of time and cost for production. To solve this, a 3D printing process was introduced, but there is a problem that it is difficult to produce precise molds due to the low resolution of the 3D printer. To solve this problem, the inventor of the present disclosure has invented an assembly type microneedle mold that can produce various molds by freely combining microneedle tips of various sizes and lengths on a mold plate (1).

[0055] The present disclosure provides an assembly type microneedle mold (30) comprising: a mold plate (1) having a microneedle base shape protruding in an upward direction; and a plurality of separated microneedle pins (2), wherein the mold plate (1) includes a plurality of slots into which the needle portions of the microneedle pins (2) can be inserted.

[0056] Here, the mold plate (1) may include the shape of a base portion, which is a part of the microneedle shape excluding the needle portion as shown in FIG. 1, and is a part where the microneedle is not inserted into the skin. The shape of the base portion shown in FIG. 1 is exemplary and is not limited thereto. The base portion includes a slot for inserting the needle portion of the microneedle pin (2).

[0057] In addition, as shown in FIG. 1, the back surface of the mold plate (1) may further include a fixing device for inserting and fixing a microneedle pin (2). Accordingly, the microneedle pin (2) can be freely attached and detached from the slot of the mold plate (1) and can be arranged in various ways as needed. Therefore, while conventional microneedle molds cannot be modified or deformed after production, the assembly type microneedle mold (30) of the present disclosure allows for the deformation of the mold by attaching and detaching various types of microneedle pins (2) as needed.

[0058] Specifically, the assembly type microneedle mold (30) may be used as a primary mold for forming a microneedle intaglio mold (40). Accordingly, the assembly type microneedle mold (30) has the advantage of being able to produce multiple primary molds by assembling microneedle pins (2) of a design having a desired size or shape onto a mold plate (1) as needed. Therefore, by using the assembly type microneedle mold (30) of the present disclosure, which can be assembled in various forms, as a primary mold, there is an advantage of being able to produce various microneedle intaglio molds (40) and microneedles in a short period of time at low cost.

[0059] Hereinafter, an assembled microneedle mold (30) according to an example of the present disclosure will be described in detail with reference to FIGS. 1 to 10. However, since the configuration of FIGS. 1 to 10 is merely one embodiment, it should be understood that modifications of some form or substitutions of components are all included within the scope that does not impair the scope of the rights of the present disclosure.

[0060] According to one embodiment of the present disclosure, the mold plate (1) may include a plurality of slots ranging from 1 (1x1) to 900 (30x30) arranged regularly per unit area (1cm x 1cm).

[0061] Since different microneedle pins (2) are inserted into the microneedle slots, a microneedle mold with various arrangements of microneedle tips can be produced. Specifically, as shown in FIG. 8, they can be arranged in a slanted array, and as shown in FIG. 9, the number of microneedle pins (2) to be inserted can be appropriately selected and assembled and arranged.

[0062] According to one embodiment of the present disclosure, the microneedle pin (2) can be appropriately selected and used by a person skilled in the art as long as it is made of a material that is hard enough to have good machinability and durability, such as high-speed steel or stainless steel.

[0063] When the microneedle pin (2) is made of a material such as high-speed steel, the microneedle has high durability, which has the advantage of allowing the microneedle intaglio mold (40), such as a silicone-based mold made of PDMS or Ecoflex, to be produced repeatedly.

[0064] According to one embodiment of the present disclosure, the microneedle pin (2) may include a column portion; and a needle portion.

[0065] Specifically, as disclosed in FIG. 2, the microneedle pin (2) includes a column portion (22), and the end of the pin includes a needle portion (21). As shown in FIG. 7, the microneedle pin (2) can be assembled by inserting it into the plate from the back of the plate through the slot of the plate in the upward direction of the plate. One microneedle pin (2) may be assembled for each slot of the mold plate (1), and the inserted microneedle pin (2) may be assembled such that the length and size of the needle portion are the same or different.

[0066] According to one embodiment of the present disclosure, the slot of the mold plate (1) may be larger than the size of the bottom surface of the needle portion of the microneedle pin (2) so that the needle portion of the microneedle pin (2) can be inserted. Additionally, the size of the bottom surface of the column portion of the microneedle pin (2) may be larger than the diameter of the slot. Accordingly, by referring to the section view of FIG. 4, it can be seen that only the needle portion of the microneedle pin (2) is inserted in the upward direction of the plate and assembled.

[0067] According to one embodiment of the present disclosure, the height of the microneedle needle portion may be 100 μm to 3,000 μm, but is not necessarily limited thereto. More preferably, it may be 100 μm to 3,000 μm, 100 μm to 2,500 μm, 100 μm to 2,000 μm, 200 μm to 1,500 μm, or 400 μm to 1,200 μm, but is not necessarily limited thereto.

[0068] Specifically, if the length of the needle portion of the microneedle is long, the manufactured microneedle can be used for muscle tissue treatment and stimulation, and if the length of the microneedle is short, the manufactured microneedle can be used for skin or tissue treatment and stimulation close to the skin surface. Therefore, a person skilled in the art can assemble a microneedle mold by appropriately selecting the height of the needle portion of the microneedle pin (2) according to the intended use of the microneedle to be manufactured.

[0069] In one embodiment of the present disclosure, the aspect ratio of the needle portion of the microneedle pin (2) may be 1:1 to 1:20.

[0070] Specifically, the aspect ratio of the pin needle portion may be in the range of 1:1 to 1:18, 1:1 to 1:16, 1:1 to 1:14, or 1:1 to 1:12. More specifically, the aspect ratio of the pin needle portion may be in the range of 1:1 to 1:10, 1:2 to 1:10, or 1:3 to 1:10, and more specifically, in the range of 1:4 to 1:10, but is not necessarily limited thereto. A person skilled in the art can appropriately select the aspect ratio of the microneedle pin (2) according to the purpose, use, and material of the microneedle to be manufactured.

[0071] If the aspect ratio is less than 1, microneedles manufactured in a blunt shape may have difficulty perforating the skin, and if it is greater than 10, microneedles may easily break or bend, making it difficult to perforate the skin.

[0072] In one embodiment of the present disclosure, the angle of the tip of the needle portion may be 30° or more. More specifically, it may be 30° or more, 35° or more, or 40° or more. More specifically, it may be 30° or more and 60° or less.

[0073] Since the angle of the above-mentioned tip satisfies the above range, the microneedle tip is sharply formed, allowing the manufactured microneedle to puncture the skin without pain.

[0074] According to one embodiment of the present disclosure, the microneedle needle portion may have a tip selected from the group consisting of a cone, a triangular pyramid, a square pyramid, a pentagonal pyramid, a hexagonal pyramid, and a polygonal pyramid, but is not necessarily limited thereto. Specifically, if it has a tip in the shape of a cone or a square pyramid, a microneedle with high insertion ability into the skin can be manufactured.

[0075] In addition, the microneedle needle portion may not form a step in the middle, or may form one, two, or three steps in the middle, and the microneedle tip portion may be solid or include a hollow portion, but is not necessarily limited thereto.

[0076] This assembled microneedle mold (30) is used as a primary mold for forming a microneedle intaglio mold (40), and can assemble microneedle pins (2) of various sizes and lengths in various arrangement forms on a mold plate (1).

[0077] Therefore, there is an advantage in that various shapes of intaglio microneedle molds can be produced through a single primary mold, and in particular, there is an advantage in that complex shapes that are difficult to manufacture, such as more inclined multi-channels, can be easily manufactured. In addition, the assembly type microneedle mold (30) has durability, allowing for the repeated production of microneedle intaglio molds (40) made of materials such as silicone. Furthermore, in the conventional method of forming a primary mold using a 3D printing process, the microneedle tip portion is expressed as blunt due to low resolution, but the microneedle produced through the assembly type microneedle mold (30) of the present disclosure has a sharp microneedle tip, which can improve skin penetration ability.

[0078] Hereinafter, a method for manufacturing a microneedle intaglio mold using the assembly type microneedle mold (30) of the present disclosure will be described in detail, and the length, size, and aspect ratio of the tip portion of the microneedle pin (2) are the same as those described above.

[0079] The present disclosure provides a method for manufacturing a microneedle intaglio mold (40), comprising: a step of preparing a first mold by assembling microneedle pins (2) on a mold plate (1) using the aforementioned assembly type microneedle mold (30); and a step of forming a microneedle mold having the same intaglio shape as the first mold by using a first polymer material.

[0080] In one embodiment of the present disclosure, a first mold may be formed by assembling microneedle pins (2), each having the same length and size of the tip portion, onto a mold plate (1).

[0081] In addition, a primary mold may be formed by combining microneedle tips in a slanted multi-array shape on a mold plate (1), as exemplarily illustrated in FIG. 8.

[0082] In addition, as shown in FIG. 12, hollow microneedles can be formed by combining them with a jig for hollow microneedles, using acupuncture needles or microneedles formed by metal processing. In this case, for hollow microneedles formed using acupuncture needles, a hollow microneedle combined with acupuncture needles is fabricated, and after inserting it at a desired location and depth using the acupuncture needles, only the acupuncture needles are removed to utilize the hollow microneedles as an interface.

[0083] The arrangement method of the microneedle pins (2) of such an assembly-type microneedle mold (30) is not limited thereto, and a person of ordinary skill can produce a first mold by appropriately selecting the arrangement method as needed, taking into account the intended use and the area of ​​use.

[0084] The step of forming a microneedle mold having the same intaglio shape as the first mold can involve placing the first mold into a container containing a polymer material, and injecting the polymer material into the container containing the first mold to form a microneedle intaglio mold (40).

[0085] According to one embodiment of the present disclosure, the polymer material may be one or more selected from the group consisting of silicone-based polymers or polyurethanes. More specifically, the polymer material may be polydimethylsiloxane (PDMS), but is not necessarily limited thereto.

[0086] A microneedle mold having the same intaglio shape as the first mold can be manufactured using a first polymer material with the first mold having the above-mentioned sharp tip portion.

[0087] Various types of micro-needles can be manufactured using the above-mentioned various types of micro-needle intaglio molds (40).

[0088] According to one embodiment of the present disclosure, a method for manufacturing microneedles is provided, comprising: a step of preparing the aforementioned microneedle intaglio mold (40); a step of injecting a second polymer material into the microneedle intaglio mold (40); a vacuum placement step in which the mold into which the second polymer material is injected is placed in a vacuum; a microneedle array curing step in which the second polymer material injected into the microneedle mold placed in the vacuum is cured; and a step of separating the cured microneedle array.

[0089] The above vacuum placement step allows the second polymer material to easily fill up to the end of the intaglio mold without external pressure because the mold into which the second polymer is injected is placed in a vacuum, thereby enabling the manufacture of microneedles having the same shape as the first mold.

[0090] In one embodiment of the present disclosure, the second polymer material may be a polymer solution in which an active ingredient for therapeutic purposes is dissolved in a biocompatible polymer. The microneedles prepared as described above are soluble microneedles, and may follow a method in which a drug is released as the microneedles, composed of a biodegradable material, decompose within the body. When the biodegradable polymer is used, the microneedle curing step may be degassing and drying in a vacuum atmosphere at room temperature.

[0091] In one embodiment of the present disclosure, the second polymer material may be a polyimide polymer or a shape memory polymer.

[0092] When the second polymer material used is a polyimide polymer or a shape-memory polymer, the curing step of the microneedle array may include a UV curing or hard-baking step. Specifically, it may include a primary curing step in which it is cured by irradiation with ultraviolet light, and a secondary curing step in which it is cured by being placed in an oven. Accordingly, the second polymer can be completely cured through the primary and secondary curing processes, and a person skilled in the art can appropriately select and perform the UV irradiation time, exposure time, and hard baking temperature and time. Additionally, if the second polymer is a shape-memory polymer, shape-memory properties can be designed during the curing step.

[0093] Accordingly, the mold into which the second polymer is injected can undergo the processes of first curing, second curing, and third curing so that the second polymer can be completely cured, and accordingly, the second polymer can be completely separated from the mold into which the second polymer is injected so that a microneedle having the same shape as the mold can be produced.

[0094] According to one embodiment of the present disclosure, the method may further include the step of forming a conductive layer by coating a metal electrode or a conductive polymer on the surface of the separated microneedles.

[0095] The metal and conductive polymer mentioned above can be appropriately selected and used by a person skilled in the art, and the coating method may form a conductive layer on the surface of the microneedle using one or more methods selected from the group consisting of spin coating, spray coating, inkjet printing, and dip coating, but is not necessarily limited to the coating method mentioned above.

[0096] In addition, conductive microneedles can be fabricated by utilizing a conductive polymer. The conductive polymer can be prepared by mixing a conductive polymer, such as PEDOT:PSS or MXene, with a base polymer, such as polyurethane, SEBS (Styrene-Ethylene-Butylene-Styrene), or a shape memory polymer. Specifically, it may be a solution of PEDOT:PSS and polyurethane mixed in an appropriate ratio, but is not necessarily limited thereto.

[0097] Since the above microneedles are conductive, they can be inserted into the skin to measure biosignals such as electrocardiograms, electromyograms, electroencephalograms, and nerve conductions of the body, and can also be used for electroporation to inject drugs.

[0098] Accordingly, the microneedle manufacturing method of the present disclosure can manufacture microneedles with sharp microneedle tips, and can manufacture various types of microneedles through a simple process by including multiple channels with the same or different lengths and sizes of each needle.

[0099] Next, the present disclosure provides a method for manufacturing hollow microneedles using the aforementioned assembled microneedle mold (30) and various types of hollow-generating needles (55).

[0100] The present disclosure comprises the steps of: preparing the aforementioned microneedle intaglio mold (40); injecting a second polymer material into the microneedle intaglio mold (40); and, while the second polymer material is injected, inserting a hollow-forming needle (55) along the central axis of each microneedle formation position of the intaglio mold through a needle jig (51).

[0101] A vacuum placement step in which a needle jig (51) and an intaglio mold into which a second polymer material has been injected are placed in a vacuum while the above-mentioned hollow-generating needle (55) is inserted;

[0102] A method for manufacturing hollow microneedles is provided, comprising: a microneedle array curing step of curing a second polymer material injected into a microneedle mold in a vacuum state; and a step of removing a needle jig (51) after the curing is completed, and then separating the microneedle array into which a hollow-generating needle (55) is inserted from the intaglio mold.

[0103] Additionally, depending on the application, a person skilled in the art may further include the step of removing the hollow-generating needle (55) from the microneedle array into which the hollow-generating needle (55) is inserted.

[0104] Hereinafter, the steps of preparing the aforementioned microneedle intaglio mold (40), injecting the second polymer material into the intaglio mold, and curing are identical to the manufacturing method described above, so a detailed description thereof is omitted. Below, the step of inserting a hollow-forming needle along the central axis of each microneedle formation position of the intaglio mold while the second polymer material is injected is described in detail.

[0105] In one embodiment of the present disclosure, each microneedle portion on the microneedle intaglio mold (40) may selectively have hollow-forming needles having different diameters inserted therein.

[0106] As illustrated in FIGS. 13 and 14, a needle jig (51) is used to selectively insert a hollow-forming needle (55) of various diameters into the central axis of each microneedle into which a second polymer material has been injected, thereby allowing the diameter of the hollow formed inside each microneedle to be individually controlled. Accordingly, hollow microneedles having different hollow diameters can be formed simultaneously within a single microneedle array.

[0107] With this configuration, differential design of drug delivery volume, selective control of fluid injection characteristics, and differential securing of internal space for electrode or wire insertion are possible without separate mold replacement or additional processing steps, and the degree of design freedom of the hollow structure is significantly improved. In addition, by selecting the diameter of the hollow-forming needle (55) to correspond to the external structure of the microneedle, the mechanical strength of the microneedle can be stably maintained even after the hollow is formed.

[0108] The diameter of the above-mentioned hollow-generating needle (55) may be smaller than the maximum outer diameter of the microneedle, and may be set so that the mechanical strength of the microneedle is maintained even after the hollow is formed.

[0109] Specifically, to provide mechanical strength to prevent breakage or deformation when inserting the microneedle, the ratio (D / d) of the outer diameter (D) to the inner diameter (d) of the manufactured microneedle may be 1.5 or more, 1.6 or more, 1.7 or more, 1.8 or more, or 1.9 or more as a lower limit, and although not specifically limited as an upper limit, it may be 5 or less, 4 or less, 3 or less, or 2 or less. More preferably, it may be designed within a range of 1.5 to 5, 1.5 to 3, or 1.5 to 2.

[0110] However, this is not necessarily limited thereto, and a person skilled in the art may appropriately modify and select the material of the second polymer material, the microneedle wall thickness, length, tip shape, arrangement density, characteristics of the tissue to be inserted, required flow rate, and purpose of use.

[0111] For example, the diameter of the hollow-generating needle (55) may be 10 μm or more, 15 μm or more, 20 μm or more, 25 μm or more, 30 μm or more, 40 μm or more, or 60 μm or more as a lower limit, and may be 5 mm or less, 1 mm or less, 0.5 mm or less, or 0.3 mm or less as an upper limit, or any value between the lower and upper limits. The diameter of the hollow-generating needle (55) may be in the range of 60 μm to 0.3 mm, but is not necessarily limited thereto.

[0112] In addition, the shape of the above-mentioned hollow-generating needle (55) may differ from one another in the diameter, length, cross-sectional shape, or tip structure of the needle.

[0113] For example, the hollow-generating needle (55) may be a cylindrical needle having a constant diameter over its entire length, or the hollow-generating needle (55) may include a structure in which the diameter gradually decreases at a tip or in a specific section along the length.

[0114] In this way, when the diameter of the hollow-generating needle (55) has a structure in which it decreases at the tip or in a specific section, a relatively thick wall thickness can be formed at the tip of the manufactured hollow microneedle, thereby improving mechanical strength to suppress breakage or deformation that may occur during skin insertion. Additionally, as the diameter of the hollow decreases at the tip, premature leakage or backflow of the drug or fluid is suppressed, thereby improving delivery stability.

[0115] Furthermore, a structure in which the diameter of the hollow decreases in a specific section along the length direction can form a step or a reduction section within the hollow, thereby enabling control of fluid delivery speed, selective control of drug release location, or a position fixing effect when inserting electrodes or wires.

[0116] As described above, by selecting various shapes of the hollow-generating needle (55), not only the diameter of the hollow of the hollow microneedle but also the length, shape, and internal structure of the hollow can be selectively controlled, and accordingly, hollow microneedles suitable for various purposes such as drug delivery, fluid injection, electrode or wire insertion can be easily manufactured.

[0117] The method for manufacturing hollow microneedles of the present disclosure can be performed by combining an intaglio mold into which a second polymer material is injected and a jig for hollow microneedles, so that a hollow-generating needle (55) is accurately inserted along the central axis of the microneedle formation location, and the insertion location, depth, and alignment state can be stably maintained during the curing process.

[0118] In conclusion, the method for manufacturing hollow microneedles of the present disclosure has the advantage of being able to design various external shapes, lengths, arrangements, and tip shapes of microneedles by using an assembly-type microneedle mold (30), and additionally, by selectively applying various types of hollow-generating needles (55) during the microneedle manufacturing process, hollow microneedles with different diameters, lengths, shapes, and internal structures can be stably manufactured within a single manufacturing process.

[0119] 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.

[0120]

[0121] [Explanation of the symbol]

[0122] 1: Mold plate

[0123] 2: Microneedle pin

[0124] 21: Needle portion of the microneedle pin

[0125] 22: Pillar part of the microneedle pin

[0126] 30: Assembly type microneedle mold

[0127] 40: Microneedle Engraving Mold

[0128] 50: Hollow microneedle jig

[0129] 51: Needle Jig

[0130] 52: Mold Jig

[0131] 55: Needle for creating hollows

Claims

1. A mold plate including a microneedle base portion shape protruding in an upward direction; and a plurality of separated microneedle pins; comprising, The above mold plate includes a plurality of slots into which the needle portion of a microneedle pin can be inserted, and An assembly type microneedle mold in which the microneedle pin is detachably attached to the mold plate.

2. In Paragraph 1, The above mold plate is an assembled microneedle mold comprising a plurality of slots ranging from 1 (1x1) to 900 (30x30) arranged regularly per unit area (1cm x 1cm).

3. In Paragraph 1, An assembled microneedle mold wherein the microneedle pin comprises a pillar portion; and a microneedle needle portion.

4. In Paragraph 1, An assembled microneedle mold having a height of 100 μm to 3,000 μm for the microneedle needle portion.

5. In Paragraph 1, An assembled microneedle mold having an aspect ratio of 1:1 to 1:20 for the microneedle needle portion.

6. In Paragraph 1, An assembled microneedle mold in which the angle of the tip of the needle portion of the above microneedle pin is 30° or more.

7. In Paragraph 1, An assembled microneedle mold having a tip selected from the group consisting of a cone, a triangular pyramid, a square pyramid, a pentagonal pyramid, a hexagonal pyramid, and a polygonal pyramid.

8. A step of preparing a first mold by assembling microneedle pins onto a mold plate using an assembly-type microneedle mold according to claim 1; and A method for manufacturing a microneedle intaglio mold, comprising the step of forming a microneedle mold having the same intaglio shape as the first mold using a first polymer material.

9. In Paragraph 8, A method for manufacturing a microneedle intaglio mold, wherein a first mold is formed by assembling microneedle pins, each having the same length and size of the tip portion, onto a mold plate.

10. In Paragraph 8, A method for manufacturing a microneedle intaglio mold, wherein one or more types of microneedle pins with different lengths and sizes of tip portions are assembled on a mold plate to form a first mold.

11. In Paragraph 10, A method for manufacturing a microneedle intaglio mold, wherein a first mold is formed by combining microneedle tips in a slanted multi-array shape with a mold plate.

12. In Paragraph 8, A method for manufacturing a microneedle intaglio mold, wherein the first polymer material is one or more selected from the group consisting of silicone-based polymers or polyurethane.

13. A microneedle intaglio mold manufactured according to any one of paragraphs 8 through 12.

14. Step of preparing a microneedle engraving mold according to Paragraph 13; A step of injecting a second polymer material into the above-mentioned microneedle intaglio mold; A vacuum placement step in which the mold into which the second polymer material is injected is placed in a vacuum; A microneedle array curing step in which a second polymer material injected into a microneedle mold placed in the vacuum above is cured; and A method for manufacturing microneedles comprising the step of separating the above-mentioned cured microneedle array.

15. In Paragraph 14, A method for manufacturing microneedles, wherein the second polymer material is one or more selected from the group consisting of a polymer solution in which the active ingredient for therapeutic purposes is dissolved in a biocompatible polymer, a polyimide polymer, and a shape memory polymer.

16. In Paragraph 15, A method for manufacturing microneedles, further comprising the step of forming a conductive layer by coating a metal electrode or a conductive polymer on the surface of the separated microneedles.

17. Step of preparing a microneedle engraving mold according to Paragraph 13; A step of injecting a second polymer material into the above-mentioned microneedle intaglio mold; A step of inserting a hollow-forming needle along the central axis of each microneedle formation position of an intaglio mold through a needle jig while the second polymer material is injected; A vacuum placement step of placing a needle jig and an intaglio mold injected with a second polymer material into a vacuum while the above-mentioned hollow-generating needle is inserted; A microneedle array curing step for curing a second polymer material injected into a microneedle intaglio mold in the above vacuum state; A method for manufacturing hollow microneedles comprising: a step of removing the needle jig after the above curing is completed, and then separating the microneedle array into which the hollow-generating needle is inserted from the above intaglio mold; and a step of removing the hollow-generating needle from the microneedle array.

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