JP2018175240A - Micro needle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a micro needle which can maintain a state where the needle is punctured into a skin for a predefined period of time and which is less likely to fall off from the skin after puncture.SOLUTION: A micro needle of the present invention is configured to be inclined with respect to a vertical direction of a substrate 12. At least a part of a plurality of projections 11 are configured to be inclined with respect to the vertical direction of the substrate 12 (a configuration which is not in a square-pyramid shape or a square-prismatic shape) such that the needle is less likely to fall off from the skin after puncture. Further, the projections are divided into a plurality of regions in which an inclination directions in each of the regions are different. Such a configuration of the micro needle having the projections in different inclination direction per regions can be less likely to fall off from the skin after puncture.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a microneedle used for medical applications, MEMS (Micro Electro Mechanical Systems) devices, optical members, drug discovery, cosmetics, cosmetic applications and the like. It relates to a microneedle to puncture the skin.

  Methods for administering the drug to the human body include oral administration, puncturing the skin dermis layer or vein with a syringe, administration to the topical dermal layer by application of an ointment onto the skin surface, topical dermal layer by the method of application to the skin surface Administration, and the like.

  Among them, in recent years, development of a microneedle provided with a plurality of minute needles, which are projections, has been advanced as a device for administering a drug into the body by sticking or using a puncturing method using an applicator. The material of the microneedle is selected to be harmless even if it dissolves or remains in the living body so that there is no adverse effect even if part of the needle-shaped body is broken by puncture and remains in the body.

WO 2005/058162 JP, 2006-334419, A

  An object of the microneedle of the present invention is to provide a microneedle which can hold the punctured state for a certain period of time after puncturing the skin and which is not easily detached from the skin after puncturing.

In order to solve the above-mentioned subject, according to the invention concerning Claim 1, it is a microneedle provided with a plurality of projection parts in one side of a substrate, and a plurality of the projection parts intersect at a junction with the substrate The plurality of projections are formed in the form of a lattice, and the plurality of projections are a first surface at the joint portion, a second surface facing the first surface, and a first surface and a second surface at the joint portion. The first surface, the second surface, the third surface, and the fourth surface are formed of four surfaces of a third surface that intersects the third surface and a fourth surface that faces the third surface. The fourth surface is formed to be in the same plane between adjacent grid-like projections along the two intersecting directions, and the plurality of projections are at least the first surface. in the angle theta _2A of the substrate and the angle theta _1A of the substrate and the second surface That the region A, the plurality of protrusions is formed by the region B is the angle theta _2B of the substrate and the first surface and the second surface and the angle theta _1B of the substrate, the following relationship It was set as the microneedle characterized by satisfying the formula.
[Relational expression]
θ _1A ≠ θ _1B
θ _1A ≠ θ _2A

The invention according to claim 2 is the microneedle according to claim 1, wherein the difference between θ _1A and θ _2A is in the range of 3 ° or more and 40 ° or less.

  By using the microneedle of the present invention, it is possible to obtain a microneedle that does not easily come off the skin after puncturing.

FIG. 1 is an explanatory view (first embodiment) of the microneedle of the present invention. FIG. 1 (A) is a perspective view of the microneedle of the present invention, FIG. 1 (B) is a top view from the side of the protrusion of the microneedle of the present invention, and FIG. 1 (C) is the present invention FIG. 1 (D) is a cross-sectional view of the microneedle of the present invention, taken along the line YY '. FIG. 2 is an explanatory view (first embodiment) of the microneedle of the present invention. FIGS. 2A and 2B are both top views from the side of the protrusion of the microneedle of the present invention, and are the same as FIG. 1B. FIG. 3 is an explanatory view (second embodiment) of the microneedle of the present invention. Fig. 3 (A) is a perspective view of the microneedle of the present invention, Fig. 3 (B) is a top view from the side of the protrusion of the microneedle of the present invention, and Fig. 3 (C) is the present invention. 3D is a cross-sectional view of the microneedle of the present invention, and FIG. 3D is a YY 'cross-sectional view of the microneedle of the present invention. FIG. 4 is an explanatory view (third embodiment) of the microneedle of the present invention. Fig. 4 (A) is a perspective view of the microneedle of the present invention, Fig. 4 (B) is a top view from the side of the protrusion of the microneedle of the present invention, and Fig. 4 (C) is the present invention. 4D is a cross-sectional view of a microneedle of the present invention, and FIG. 4 (D) is a YY 'cross-sectional view of a microneedle of the present invention. FIG. 5 is an explanatory view (fourth aspect) of the microneedle of the present invention. Fig. 5 (A) is a perspective view of the microneedle of the present invention, Fig. 5 (B) is a top view from the side of the protrusion of the microneedle of the present invention, and Fig. 5 (C) is the present invention. 5D is a cross-sectional view of the microneedle of the present invention, and FIG. 5D is a YY 'cross-sectional view of the microneedle of the present invention. FIG. 6 is an explanatory view (fifth aspect) of the microneedle of the present invention. FIG. 6 (A) is a perspective view of the microneedle of the present invention, FIG. 6 (B) is a top view from the side of the protrusion of the microneedle of the present invention, and FIG. 6 (C) is the present invention 6D is a cross-sectional view of the microneedle of the present invention, and FIG. 6 (D) is a YY 'cross-sectional view of the microneedle of the present invention. FIG. 7 is an explanatory view of the principle of the method of manufacturing a microneedle according to the present invention. FIG. 8 is an explanatory view (cross-sectional view) of a method of manufacturing a microneedle according to the present invention. FIG. 9 is an explanatory view (cross-sectional view) of a method of manufacturing a microneedle according to the present invention. FIG. 10 is an explanatory view (perspective view) of a method of manufacturing a microneedle according to the present invention. FIG. 11 is an explanatory view (cross-sectional view) of the method of manufacturing the microneedle of the present invention.

  The microneedle of the present invention will be described using the drawings. In addition, the microneedle of this invention is not limited to the description based on drawing or drawing.

  FIG. 1 is an explanatory view (first embodiment) of the microneedle of the present invention. FIG. 1 (A) is a perspective view of the microneedle of the present invention, FIG. 1 (B) is a top view from the side of the protrusion of the microneedle of the present invention, and FIG. 1 (C) is the present invention FIG. 1 (D) is a cross-sectional view of the microneedle of the present invention, taken along the line YY '.

The microneedle 1 of the present invention comprises a plurality of protrusions 11 on a substrate 12 on a flat plate,
The plurality of protrusions 11 are formed in a grid shape that intersects at a bonding point with the substrate 12. The plurality of protrusions have four side surfaces at the junction with the substrate 12. Each of the four side surfaces is a first surface, a second surface facing the first surface, a third surface intersecting the first surface and the second surface at the joint point, a third surface facing the third surface It will be the side of 4. At this time, the first surface, the second surface, the third surface and the fourth surface are formed to be in the same plane between adjacent grid-like protrusions along the intersecting two directions. Be done.

  An explanatory view (first aspect) of the microneedle of the present invention is shown in FIG. FIGS. 2A and 2B are the same as FIG. 1B. In FIG. 2A, the surfaces shown in black are present in the same plane. Similarly, the surfaces shown in black in FIG. 2A exist in the same plane.

In the microneedle 1 of the present invention shown in FIG. 1, the plurality of protrusions 11 provided on the substrate 12 are divided into two regions, region A and region B.
In the region A, an angle θ _1A between the first surface of each protrusion and the substrate 12, an angle θ _2A between the second surface and the substrate 12, an angle θ _3A between the third surface and the substrate, the fourth The angle θ _4A between the surface of the substrate and the substrate 12 is the same among the protrusions. On the other hand, the angle theta _1A of the first surface and the substrate 12 and the angle theta _2A and the second surface and the substrate 12 have different values. In the microneedle of the present invention, at least a part of the plurality of protrusions 11 has a structure inclined with respect to the vertical direction of the substrate 12 instead of the square pyramid shape or the square prism shape at the junction with the substrate 12. By taking a structure in which at least a part of the plurality of protrusions 11 are inclined with respect to the vertical direction of the substrate 12, it is possible to make it difficult to remove the skin after puncturing.

In the microneedle of the present invention, by setting θ _1A ≠ θ _2A , the structure is inclined with respect to the vertical direction of the substrate 12. By taking a structure in which at least a part of the plurality of protrusions 11 are inclined with respect to the vertical direction of the substrate 12 (a structure that is not a square pyramid shape or a square prism shape), it is possible to make it difficult to puncture the skin.

Furthermore, in the microneedle according to the present invention, the difference between the angle θ _1A between the first surface and the substrate 12 and the angle θ _2A between the second surface and the substrate 12 is in the range of 3 ° to 40 °. Is preferred. By setting the difference to 3 ° or more, by taking a more inclined structure with respect to the vertical direction of the substrate 12, it is possible to make it difficult for the skin to come off after puncture. On the other hand, if the difference exceeds 40 °, one of the angles needs to be low, which may make it difficult to puncture the skin.

On the other hand, in the region B, the angle theta _1B of the first surface and the substrate 12 at the _protrusions, the second surface and the angle theta _2B of the substrate _12, the third surface and the substrate angle theta _3B of _the The angles θ _{4 B} between the fourth surface and the substrate 12 are all the same among the protrusions.

Next, the difference in the shape of the protrusion of the region A and the protrusion of the region B will be described. In the microneedles of the present invention, the first surface and the first surface and the angle theta _1B of the substrate 12 of the angle theta _1A and the region B of the substrate 12 in the region A are different. By setting it as the microneedle of this structure, it can be made hard to remove after puncturing skin.

In the microneedle of the present invention, by setting θ _1A ≠ θ _{1 B} , the projection is divided into a plurality of areas, and the inclination direction of the projection is different for each divided area. As described above, the microneedles provided with the projections having different inclination directions for each area can make it difficult for the skin to come off after puncture.

Further, in the microneedle of FIG. 1, in the region A, the angle θ _{1 A} between the first surface and the substrate 12 is smaller than the angle θ _{2 A} between the second surface and the substrate 12, and in the region B with the first surface The angle θ _{1 B} formed by the substrate 12 is larger than the angle θ 2 _B formed between the second surface and the substrate 12. With such a structure, it is possible to make it difficult for the skin to come out after puncturing.

In the microneedle of the present invention, the angles θ _1A and θ _1B between the first surface and the substrate 12, the angles θ _2A and θ _2B between the second surface and the substrate 12, the third surface and the substrate The angles θ _3A and θ _3B and the angles θ _4A and θ _4B between the fourth surface and the substrate 12 are preferably set in the range of 45 ° or more and 90 ° or less. More preferably, it is preferable to set in the range of 60 degrees or more and 90 degrees or less.

  An explanatory view (second aspect) of the microneedle of the present invention is shown in FIG. Fig. 3 (A) is a perspective view of the microneedle of the present invention, Fig. 3 (B) is a top view from the side of the protrusion of the microneedle of the present invention, and Fig. 3 (C) is the present invention. 3D is a cross-sectional view of the microneedle of the present invention, and FIG. 3D is a YY 'cross-sectional view of the microneedle of the present invention.

Similar to the microneedle of FIG. 1, the microneedle of FIG. 3 also has different shapes of protrusions in the two regions A and B. The microneedle of FIG. 3 differs from the shape of the microneedle of FIG. 1 in that in the region A, the angle θ _1A between the first surface and the substrate 12 is larger than the angle θ _2A between the second surface and the substrate 12 angle theta _1B of the area B the first surface and the substrate 12 is smaller than the angle theta _2B between the second surface and the substrate 12. With such a structure, it is possible to make it difficult for the skin to come out after puncturing.

  The microneedles of FIGS. 1 and 3 were divided into two equal regions, region A and region B. In the regions A and B, the number of corresponding protrusions is the same. However, in the microneedle of the present invention, the numbers do not necessarily have to be the same between the regions A and B.

  FIG. 4 is an explanatory view (third embodiment) of the microneedle of the present invention. Fig. 4 (A) is a perspective view of the microneedle of the present invention, Fig. 4 (B) is a top view from the side of the protrusion of the microneedle of the present invention, and Fig. 4 (C) is the present invention. 4D is a cross-sectional view of a microneedle of the present invention, and FIG. 4 (D) is a YY 'cross-sectional view of a microneedle of the present invention.

  FIG. 5 is an explanatory view (fourth embodiment) of the microneedle of the present invention. Fig. 5 (A) is a perspective view of the microneedle of the present invention, Fig. 5 (B) is a top view from the side of the protrusion of the microneedle of the present invention, and Fig. 5 (C) is the present invention. 5D is a cross-sectional view of the microneedle of the present invention, and FIG. 5D is a YY 'cross-sectional view of the microneedle of the present invention.

The microneedle 1 of the present invention shown in FIGS. 4 and 5 is divided into a region A, a region B, a region C and a region D in which the plurality of protrusions 11 provided on the substrate 12 are two regions.
In the region A, an angle θ _1A between the first surface of each protrusion and the substrate 12, an angle θ _2A between the second surface and the substrate 12, an angle θ _3A between the third surface and the substrate, the fourth The angle θ _4A between the surface of the substrate and the substrate 12 is the same among the protrusions. On the other hand, the angle theta _1A of the first surface and the substrate 12 and the angle theta _2A and the second surface and the substrate 12 have different values. Further, the angle theta _3A of the third surface and the substrate 12 is the angle theta _4A of the fourth surface and the substrate 12 have different values.
Similarly, in the region B, the first surface and the angle theta _1B of the substrate 12 in the protruding _portion, the second surface and the angle theta _2B of the substrate _12, the third surface and the substrate angle theta _3B of The angles θ _{4 B} between the fourth surface and the substrate 12 are all the same among the protrusions. On the other hand, the angle theta _1B of the first surface and the substrate 12 and the angle theta _2B between the second surface and the substrate 12 have different values. Further, the angle theta _3B of the third surface and the substrate 12 is the angle theta _4B of the fourth surface and the substrate 12 have different values.
Similarly, in the region C, the angle θ _1C between the first surface of each protrusion and the substrate 12, the angle θ _2C between the second surface and the substrate 12, and the angle θ _3C between the third surface and the substrate The angles θ _{4 C} between the fourth surface and the substrate 12 are all the same among the protrusions. On the other hand, the angle θ _{1 C} between the first surface and the substrate 12 and the angle θ _{2 C} between the second surface and the substrate 12 take different values. Further, the angle θ _{3 C} between the third surface and the substrate 12 and the angle θ _{4 C} between the fourth surface and the substrate 12 take different values.
Similarly, in the region D, the angle θ _1D between the first surface of each protrusion and the substrate 12, the angle θ _2D between the second surface and the substrate 12, and the angle θ _3D between the third surface and the substrate The angle θ _4D between the fourth surface and the substrate 12 is the same among the protrusions. On the other hand, the angle θ _1D between the first surface and the substrate 12 and the angle θ _2D between the second surface and the substrate 12 take different values. Further, the angle theta _4D the third surface and the angle theta _3D and the fourth substrate 12 side and the substrate 12 have different values.

  The microneedle shown in FIG. 4 and FIG. 5 can also be made difficult to come off after puncturing the skin by adopting a structure in which some of the plurality of protrusions 11 are inclined with respect to the vertical direction of the substrate 12.

  FIG. 6 is an explanatory view (fifth aspect) of the microneedle of the present invention. FIG. 6 (A) is a perspective view of the microneedle of the present invention, FIG. 6 (B) is a top view from the side of the protrusion of the microneedle of the present invention, and FIG. 6 (C) is the present invention 6D is a cross-sectional view of the microneedle of the present invention, and FIG. 6 (D) is a YY 'cross-sectional view of the microneedle of the present invention.

In the microneedle 1 of the present invention shown in FIG. 6, the plurality of protrusions 11 provided on the substrate 12 are divided into two regions, region A, region B and region C.
In the region A, an angle θ _1A between the first surface of each protrusion and the substrate 12, an angle θ _2A between the second surface and the substrate 12, an angle θ _3A between the third surface and the substrate, the fourth The angle θ _4A between the surface of the substrate and the substrate 12 is the same among the protrusions. On the other hand, the angle theta _1A of the first surface and the substrate 12 and the angle theta _2A and the second surface and the substrate 12 have different values. Further, the angle theta _3A of the third surface and the substrate 12 is the angle theta _4A of the fourth surface and the substrate 12 have different values.
Similarly, in the region B, the first surface and the angle theta _1B of the substrate 12 in the protruding _portion, the second surface and the angle theta _2B of the substrate _12, the third surface and the substrate angle theta _3B of The angles θ _{4 B} between the fourth surface and the substrate 12 are all the same among the protrusions. On the other hand, the angle theta _1B of the first surface and the substrate 12 and the angle theta _2B between the second surface and the substrate 12 have different values. Further, the angle theta _3B of the third surface and the substrate 12 is the angle theta _4B of the fourth surface and the substrate 12 have different values.
On the other hand, in the region C, the angle θ _1c between the first surface of each protrusion and the substrate 12, the angle θ _2c between the second surface and the substrate 12, the angle θ _3c between the third surface and the substrate, The angles θ _{4 c} between the fourth surface and the substrate 12 are all the same among the protrusions.
An angle θ _1c between the first surface and the substrate 12, an angle θ _2c between the second surface and the substrate 12, an angle θ _3c between the third surface and the substrate, and an angle between the fourth surface and the substrate 12 The angle θ _{4 c} takes the same value, and the shape of the projection becomes a square pyramid. As described above, the microneedle according to the present invention may have a square pyramidal protrusion that has θ _{1 c} = θ _{2 c} = θ _{3 c} = θ _{4 c} .

The microneedle of the present invention is described in further detail.
The shape of the protrusion 11 of the microneedle according to the present invention takes a quadrangular pyramid shape or a quadrangular prism shape at the junction with the substrate 12. On the other hand, various shapes can be selected as appropriate for the tip. As shown in FIG. 1 and FIG. 3, it may be a square pyramid shape, or the tip may be flat. In addition, necks or steps may be provided on the side surfaces.

  Further, in the microneedle of the present invention, the number of protrusions 11 is not particularly limited as long as it is two or more.

  The length H of the protrusion 11 is the length from the first surface 12 A to the tip of the protrusion 11 in the thickness direction of the substrate 12, that is, in the direction orthogonal to the first surface 12 A of the base 21. is there. The length H of the projection 11 is preferably 10 μm or more and 2000 μm or less, and the length H of the projection 11 is the depth necessary for the hole to be formed by the projection 22 in this range. Depending on the When the target of perforation is the skin of the human body and the bottom of the hole is set in the stratum corneum, the length H is preferably 10 μm to 300 μm, and more preferably 30 μm to 200 μm. When the bottom of the hole penetrates the stratum corneum and is set to a depth not reaching the nerve layer, the length H is preferably 200 μm to 700 μm, and more preferably 200 μm to 500 μm, More preferably, it is 200 μm or more and 300 μm or less. When the depth of the bottom of the hole is set to reach the dermis, the length H is preferably 200 μm or more and 500 μm or less. When the bottom of the hole is set to a depth to reach the epidermis, the length H is preferably 200 μm or more and 300 μm or less.

  A thermoplastic resin or the like can be used as the material of the microneedles 1. As a thermoplastic resin, for example, polyglycolic acid, polylactic acid, polylactic acid-polyglycolic acid copolymer, polyethylene, polypropylene, polystyrene, polyamide, polycarbonate, polyacrylonitrile, cyclic polyolefin, polycaprolactone, acrylic, urethane resin, aroma Group polyether ketones and epoxy resins.

  In addition, the material of the microneedle may be a material that can be dissolved by the moisture of the skin, that is, a water-soluble material. As the water-soluble material, water-soluble polymers and polysaccharides can be used. Examples of water-soluble polymers include carboxymethylcellulose (CMC), methylcellulose (MC), hydroxypropylcellulose (HPC), hydroxypropyl methylcellulose (HPMC), polyvinyl alcohol (PVA), polyacrylic acid-based polymer, polyacrylamide (PAM), Polyethylene oxide (PEO), pullulan, alginate, pectin, chitosan, chitosan succinamide, and oligochitosan can be mentioned. Among these water-soluble polymers, chitosan, chitosan succinamide, carboxymethylcellulose (CMC), hydroxypropylcellulose (HPC), and hydroxypropylmethylcellulose (HPMC) are preferable because of their high biological safety. . Moreover, examples of polysaccharides include trehalose and maltose.

  In addition, as a material of the microneedles, metal materials, ceramic materials and the like can also be used. As the metal material, ceramics such as alumina, aluminum nitride and machinable ceramics, silicon, silicon carbide, quartz and the like can also be used. However, in the present invention, the forming material of the microneedle is not limited to these.

Next, a method of manufacturing the microneedle of the present invention will be described. However, the method of manufacturing the microneedle of the present invention is not limited to the present manufacturing method.
FIG. 7 shows an explanatory view of the principle of the method of manufacturing a microneedle according to the present invention.
The microneedle of this invention processes a plate-like member using a grinding process, and manufactures a microneedle. Here, “grinding” refers to a processing method in which a workpiece is scraped off by the extremely hard and fine abrasive grains constituting the grindstone using a grinding stone rotating at high speed. For example, a dicing blade may be used as a grinding wheel. The microneedle of the present invention is manufactured by using the plate-like member 2 and operating the grinding stone 3 in a straight line, and repeating the work of forming the groove.

An explanatory view (cross-sectional view) of the method of manufacturing the microneedle of the present invention is shown in FIG. 8 and FIG.
The linear groove 4 is formed by grinding using the first dicing blade 3A having the inclination angle φS in the plate member 2 (FIGS. 8A and 8B). The inclination angle φS of the inclined surface of the first dicing blade 3S determines the angle θ between the substrate 12 and the surface of the projection 11 on the bonding surface of the substrate 12 and the projection 11 of the microneedle finally formed. By repeating these operations, linear grooves are formed. This grinding process is performed repeatedly (FIG. 8C, FIG. 8D).

  Next, the linear groove 4 is formed by grinding using the second dicing blade 3B having the inclined surface φB (FIGS. 9E and 9F). The inclination angle φT of the inclined surface of the second dicing blade 3T determines the angle θ between the substrate 12 and the surface of the protrusion 11 in the bonding surface of the microneedle substrate 12 and the protrusion 11 to be finally formed. This grinding process is repeatedly performed (FIG. 8G, FIG. 8H).

FIG. 10 shows an explanatory view (perspective view) of the method of manufacturing the microneedle of the present invention.
By performing this operation, a structure having a shape as shown in FIG. 10A is manufactured. Furthermore, the microneedle 1 of this invention like FIG. 10B is produced by performing the same grinding process in the direction orthogonal to the produced linear groove.

  The microneedle produced by grinding is used as a microneedle original plate. FIG. 11 is an explanatory view (cross-sectional view) of the method of manufacturing the microneedle of the present invention. Next, the filling layer 5 is formed on the microneedle original plate 1 'formed by the above-mentioned method, and the concave copying plate 6 is formed by peeling the filling layer 5 from the microneedle original plate 1' (FIG. 11A, FIG. 11B, FIG. 11C). By producing an integral molded replica plate 6 with high mechanical strength, a large number of microneedles can be manufactured with the same replica plate 6, so that the production cost can be lowered and the productivity can be improved. Become.

  The material of the filling layer is not particularly limited, and it is possible to select a material in consideration of the shape followability to function as a replica plate, the transfer product in transfer processing and forming described later, durability and releasability. For example, nickel, a thermosetting silicone resin, or the like may be used as the filling layer. When nickel is selected, a plating method, a PVD method, a CVD method, etc. may be mentioned as a method of forming the filling layer.

  Moreover, as a peeling method of a filling layer and microneedle original plate 1 ', peeling etc. by physical peeling force can be used.

  Next, the replication plate 6 is filled with the microneedle material to form the microneedles 1. The method of filling the microneedle material is not limited, but from the viewpoint of productivity, imprinting, hot embossing, injection molding, extrusion and casting can be suitably used. The microneedle is manufactured by the above.

Example 1
Example 1 is shown below. In Example 1, a microneedle composed of the region A and the region B shown in FIG. 1 was produced.

  First, a plurality of dicing blades containing diamond abrasive having tip portions having different inclination angles were prepared. Next, grinding was performed to form linear grooves on the surface of the alumina substrate 1 by grinding using a dicing blade. Further, the same grinding process was performed in the direction orthogonal to the linear grooves to produce a microneedle original plate.

  Next, in order to duplicate the manufactured microneedles, a step of using the microneedle master plate as a mother die, making a duplicate plate from the mother die, and performing transfer processing and molding was carried out. First, a nickel film was formed on the surface of the microneedle original plate by plating. Next, the nickel film was peeled off from the microneedle original plate to prepare a duplicate plate. Next, the replica plate was transferred to polyglycolic acid by imprinting to obtain a polyneedle microneedle of Example 1.

In the obtained microneedle of Example 1, 36 projections of 6 rows × 6 columns on the substrate are formed in a lattice. The dimensions of the protrusions in the region A and the region B are as follows.
(Area A)
Number of needles: 18 (3 x 6)
Needle height H 700 μm
Angle θ _1A 85 °
Angle θ _2A 65 °
Angle θ _3A 75 °
Angle θ _4A 75 °
(Area B)
Number of needles: 18 (3 x 6)
Needle height H 700 μm
Angle θ _1A 65 °
Angle θ _2A 85 °
Angle θ _3A 75 °
Angle θ _4A 75 °

(Comparative example 1)
Below, the comparative example 1 is shown.

  Example 1 A dicing blade containing diamond abrasive was prepared. Next, grinding was performed to form linear grooves on the surface of the alumina substrate 1 by grinding using a dicing blade. Further, the same grinding process was performed in the direction orthogonal to the linear grooves to produce a microneedle original plate.

  Next, in order to duplicate the manufactured microneedles, a step of using the microneedle master plate as a mother die, making a duplicate plate from the mother die, and performing transfer processing and molding was carried out. First, a nickel film was formed on the surface of the microneedle original plate by plating. Next, the nickel film was peeled off from the microneedle original plate to prepare a duplicate plate. Next, the duplicate plate was transferred to polyglycolic acid by imprinting to obtain a polyneedle microneedle of Comparative Example 1.

In the obtained microneedle of Comparative Example 1, 36 projections of 6 rows × 6 columns on the substrate are formed in a lattice. The dimensions of the protrusions are as follows.
Needle height H 700 μm
Angle θ _1A 75 °
Angle θ _2A 75 °
Angle θ _3A 75 °
Angle θ _4A 75 °

(Evaluation)
For the microneedles of Example 1 and Comparative Example 1 obtained by preparing artificial skin, the protrusions of the microneedles are punctured into the artificial skin, and then the protrusions of the microneedles are pulled out manually by five times. , The power at the time of pulling out was evaluated. It was confirmed that the microneedle of Example 1 requires a large force at the time of withdrawal as compared with the microneedle of Comparative Example 1. Thereby, it was confirmed that the microneedle of Example 1 is a microneedle which does not easily come off the skin after puncturing.

  The present invention can be used to manufacture microneedles used for medical applications, MEMS (Micro Electro Mechanical Systems) devices, optical members, drug discovery, cosmetics, cosmetic applications and the like.

DESCRIPTION OF SYMBOLS 1 microneedle 11 projection part 12 board | substrate 2 plate-shaped member 3 grinding wheel 3A dicing blade 3B dicing blade 4 linear groove 5 filling layer 6 duplication plate 1 'microneedle original plate

Claims (2)

A microneedle comprising a plurality of protrusions on one side of a substrate,
The plurality of protrusions are formed in a grid shape intersecting at a junction with the substrate, and the plurality of protrusions are a first surface at the junction, a second surface facing the first surface, and And a fourth surface that intersects the first surface and the second surface at the junction, and a fourth surface that faces the third surface, and
The first surface, the second surface, the third surface, and the fourth surface may be in the same plane between adjacent grid-like protrusions along the intersecting two directions. Is formed and
Wherein the plurality of protrusions, and the area A is the angle theta _2A of at least the first said surface and the angle theta _1A of the substrate second surface and the substrate, the plurality of protrusions wherein the second is formed by the region B is the angle theta _2B of the first plane and the angle theta _1B and the second surface of the substrate and the substrate, the micro-needle and satisfies the following relationship.
[Relational expression]
θ _1A ≠ θ _1B
θ _1A ≠ θ _2A The microneedle according to claim 1, wherein the difference between θ _1A and θ _2A is in the range of 3 ° to 40 °.

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