JP7421773B2 - microneedle array - Google Patents

Description

The present invention relates to a microneedle array that can administer medicine into the body, for example, instead of a conventionally used syringe.

In the future, as the aging of society progresses, the proportion of medical care in the social system will increase. For this reason, for example, as a measure to reduce the frequency of hospital visits for the elderly and busy people, and as part of home medical care for areas with a shortage of doctors and hospitals, such as remote and depopulated areas, There will be a growing need to administer medication at home based on a doctor's prescription.
BACKGROUND ART A large proportion of medical treatment involves surgical treatment of affected areas such as trauma, and medication therapy, and a large proportion of medication therapy involves intracorporeal administration using a syringe. Medication using a syringe is usually administered at a hospital by a qualified person such as a doctor or nurse, but in some cases, such as administering insulin for diabetes, patients themselves are allowed to administer it at home. Some are.

The advantage of using a syringe to administer medication is that it can be administered directly under the skin or into a blood vessel, but the disadvantages are that it can be painful during injection and that scars (injection marks) may remain or swell as the number of doses increases.
Therefore, instead of a syringe, it has been considered to use a microneedle array made of resin or metal that has a plurality of microneedles with sharp tips on a pedestal (flat plate) (for example, see Patent Documents 1 and 2). .
When using this microneedle array, it is possible to eliminate pain during use (achieve painlessness) by setting the length of the microneedles to a size that allows them to reach the depth of the painless point under the skin. Furthermore, since the method of use is simply to apply the drug to the epidermis as a patch, the patient can easily administer the medication at home, which greatly reduces the burden on the patient.

JP 2019-111274 Publication Japanese Patent Application Publication No. 2018-183511

However, when multiple microneedles are punctured into the skin using the microneedle array described above, the penetration depth (penetration degree) of each microneedle into the skin varies, the puncturing performance deteriorates, and the skin is penetrated under the epidermis. There was a risk that the prescribed amount of medicine could not be injected. Here, poor puncture performance means that there is a large variation in the puncture depth of each microneedle, and good (excellent) puncture performance means that there is little variation in the puncture depth of each microneedle. , respectively.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a microneedle array capable of injecting a prescribed amount of a drug under the epidermis.

The present inventors used a conventional microneedle array, specifically, a microneedle array in which multiple microneedles of the same shape were set up on a pedestal at the same pitch, to determine the puncture depth of each microneedle. As a result of the investigation, the following findings were obtained.
In addition, as shown in FIG. 4, four types of microneedle arrays having different numbers of microneedles arranged on a pedestal were used in the investigation. These four types of microneedle arrays each contain 26 microneedles (arrangement pitch: 1.5 to 1.8 mm), 52 microneedles (arrangement pitch: 1.3 mm), and 100 microneedles (arrangement pitch: 0.6 mm). ), and 140 microneedles (arrangement pitch: 0.6 mm) are arranged, and the shapes and dimensions of the microneedles constituting each microneedle array are the same. In addition, pig skin was used as the object against which the microneedle array was pressed.

First, the average puncture depth (μm) of microneedles when four types of microneedle arrays are pressed against the skin of a pig under the same conditions will be described with reference to FIG.
As shown in Figure 5, the average puncture depth of microneedles is best when there are 52 microneedles among the four types of microneedle arrays (deep penetration), and even if it is less than this (26 needles), Moreover, at most (100 lines, 140 lines), a tendency to decrease was obtained.
Next, the results of investigating the distribution of microneedle puncture depth (height distribution) when four types of microneedle arrays are pressed against the skin of a pig under the same conditions will be explained with reference to Figure 6. . Note that FIG. 6 shows the results of measuring the puncture depth (for example, 26 locations when there are 26 microneedles) for each microneedle that constitutes each microneedle array, and the higher the value, the greater the puncture depth. This indicates that the needle is deep (deeply stuck).
As shown in Figure 6, for all four types of microneedle arrays, the microneedles are unevenly inserted in the width direction (vertical and horizontal directions) of the pedestal when viewed from above, but Microneedles placed in the outer area surrounding the inner area tended to penetrate deeper than microneedles placed in the inner area.

The results obtained from the above findings are shown below.
As the number of microneedles increases, the number of microneedles per unit area increases, which causes the force at the time of puncturing to be dispersed, resulting in poor puncturing performance.
When the number of microneedles decreased and the arrangement pitch became too wide, the skin between adjacent microneedles became susceptible to bending, resulting in poor puncturing performance.
The puncture depth differed depending on the placement position of the microneedle. In other words, the microneedles placed in the outer area surrounding this inner area penetrated deeper than the microneedles placed in the inner area of the pedestal in plan view (the inner area penetrated shallower). ).
Therefore, the present inventors have come up with the idea that by changing various conditions for each microneedle placement area, it is possible to reduce variations in the puncture depth of microneedles, that is, to improve puncturing performance.
The present invention has been made based on the above knowledge, and the gist thereof is as follows.

A microneedle array according to the present invention that achieves the above object is a microneedle array in which a large number of microneedles are arranged upright on a pedestal, and includes:
When viewed from above, microneedles A forming a microneedle group A are erected in the inner region (center region) of the pedestal, and microneedles A are erected in the outer region (outer peripheral region) surrounding the inner region. The microneedles B constituting B differ in one or more of the following: height, base width, arrangement pitch, and tip shape, and have excellent puncturing properties.

In the microneedle array according to the present invention, it is preferable that the height of the microneedles B be lower than the height of the microneedles A, provided that the heights are different.
Here, the height difference between the microneedles A and the microneedles B is preferably more than 0 μm and less than 200 μm.

In the microneedle array according to the present invention, it is preferable that the width of the base of the microneedle B is wider than the width of the base of the microneedle A, provided that the width of the base is different.
Here, the width of the base of the microneedle B is preferably 300 μm or more and 1000 μm or less.

In the microneedle array according to the present invention, it is preferable that the arrangement pitch B of the adjacent microneedles B is narrower than the arrangement pitch A of the adjacent microneedles A, provided that the arrangement pitches are different.
Here, the arrangement pitch A is preferably 1.0 mm or more and 2.0 mm or less, and the arrangement pitch B is preferably 0.5 mm or more and 1.0 mm or less.

In the microneedle array according to the present invention, the radius of curvature B of the arc-shaped tips of the microneedles B is set to the radius of curvature B of the arc-shaped tips of the microneedles A, provided that the shapes of the tips are different. It is preferable to make the radius of curvature A larger than the radius of curvature A of .
Here, it is preferable that the radius of curvature A is 5 μm or more and 20 μm or less, and the curvature radius B is 30 μm or more and 70 μm or less.

In the microneedle array according to the present invention, it is preferable that the top surface height of the inner region of the pedestal is higher than the top surface height of the outer region.
Here, the difference in height of the pedestal is preferably more than 0 μm and less than 200 μm.

The microneedle array according to the present invention has a microneedle group A standing upright in the inner region of the pedestal and a microneedle group B standing upright in the outer region surrounding the inner region. By changing one or more of the width, arrangement pitch, and shape of the tip, the variation in puncture depth (penetration degree) of multiple microneedles can be reduced compared to the conventional method (can improve puncturing performance). ), it becomes possible to inject a prescribed amount of the drug under the epidermis.

(A) to (D) are side views of microneedle arrays according to first to fourth embodiments of the present invention, respectively. It is an explanatory view showing an outline of the same microneedle array. FIG. 7 is a side view of a microneedle array according to a modified example. FIG. 3 is a plan view showing the arrangement of microneedles constituting four types of microneedle arrays used in the investigation. It is a graph showing the relationship between the number of microneedles and the average puncture depth obtained using the same four types of microneedle arrays. It is an explanatory view showing the result of measuring the puncture depth of the microneedle which constitutes the same four types of microneedle arrays.

Next, embodiments embodying the present invention will be described with reference to the attached drawings to provide an understanding of the present invention.
First, regarding the overall outline (common parts) of the microneedle arrays according to the first to fourth embodiments of the present invention shown in FIGS. 1(A) to (D), respectively, the microneedle array 10 shown in FIG. I will explain.
The microneedle array 10 is a device (medical device) that administers medication into the body instead of a conventionally used syringe. Note that the use of the microneedle array 10 is not limited to medication, but can also be used for administering beauty serums to the skin and scalp, collecting skin tissue and body fluids, and the like.

The microneedle array 10 is made of, for example, any one or a combination of two or more of resin, bio-derived material, metal, and ceramic (hereinafter also referred to as resin, etc.), and includes a pedestal 11 and a structure that stands on the pedestal 11. It has a plurality of microneedles (also referred to as needles or microneedles) 12 with sharp tips arranged. Note that the entire microneedle array does not necessarily need to be made of resin or the like, and it is sufficient that at least the microneedles are made of resin or the like. Furthermore, a metal layer can be formed on the surface of the microneedle by performing plating, thermal spraying, metal vapor deposition, or the like, if necessary.
The size of this pedestal 11 is not particularly limited, and generally has an area of about 0.5 to 40 cm ² and a thickness of about 10 to 2000 μm. In addition, the shape is square (or rectangular) in plan view, but is not particularly limited, and examples include a circle, an ellipse, a polygon (regular polygon), and even a magatama shape. It may also be in the shape of a face or the like.
Further, the shape of the microneedles 12 is conical, but may also be, for example, an elliptical cone or a polygonal pyramid (triangular pyramid, quadrangular pyramid, etc.).

For example, about 10 to 1000 microneedles 12 (preferably, the lower limit is 30 and the upper limit is 300) are arranged upright in an area of about 1 cm ² on the pedestal 11. Therefore, the size of the pedestal 11 only needs to have an area that allows the microneedles 12 to be placed thereon.
Here, the arrangement area of the plurality of microneedles 12 on the pedestal 11 is square in plan view, but it may be rectangular, circular, oval, or polygonal, and if it is a rectangle, the long sides are If it is circular, the diameter is approximately 5 to 50 mm, if it is elliptical, the major axis is approximately 5 mm, and if it is a polygon (regular polygon), each side is approximately 5 to 50 mm. Note that the short side of the rectangle can be set to have a shorter length than the long side as appropriate.
Furthermore, although the microneedles 12 are arranged on the pedestal 11 in a checkerboard pattern when viewed from above, they can also be arranged in a staggered pattern or randomly, for example. Here, dispersion in a staggered manner means that microneedles in one row are arranged in a straight line (standing upright) at regular intervals, and between adjacent rows, the microneedles in one row are arranged in a straight line at regular intervals. Refers to the state in which the microneedles are placed (erected) at a position corresponding to the center of the gap between adjacent microneedles.

Since the microneedle 12 is the part that administers medication to the human body, grooves, depressions, etc. can be formed on the surface side of the microneedle 12 as needed, and holes ( A through hole may also be formed.
Conditions such as the shape, dimensions, and number of microneedles 12, as well as the manner and range of arrangement of microneedles 12 on pedestal 11, depend on the intended use of the microneedle array (for example, the dosage required for the human body). There are no particular limitations, and various changes can be made as long as they are satisfactory.
For example, as the shape of the microneedle, it is preferable to adopt the shape described in the above-mentioned Patent Document 1, Patent Document 2, and the like. The tip side (puncture portion) of this microneedle is bifurcated, and the drug can be held in the recess formed between the two forks.

As the resin constituting the microneedle array 10, for example, biodegradable plastic (biodegradable resin), thermoplastic resin, or thermosetting resin can be used.
Biodegradable plastics are plastics that are decomposed by microorganisms, and include, for example, polylactic acid, polycaprolactone, polyhydroxyalkanoate, polyglycolic acid, denatured polyvinyl alcohol, casein, and denatured starch, with polylactic acid being particularly preferred. . This polylactic acid is made from corn and has the characteristic that it decomposes into carbon dioxide and oxygen in the human body and in the natural environment. Therefore, by making the microneedles made of polylactic acid, even if the microneedles break inside the body, they will be decomposed and absorbed within the body, making them safe for the human body.

Examples of thermoplastic resins include polycarbonate resin, polyethylene resin, polypropylene resin, AS resin, ABS resin, methacrylic acid resin, polyvinyl chloride resin, polyacetal resin, polyamide resin, modified polyphenylene ether resin, polybutylene terephthalate resin, Although polyethylene terephthalate resin and the like can be used, polycarbonate resin is preferred.
As the thermosetting resin, for example, phenol resin, epoxy resin, melamine resin, unsaturated polyester resin, polyurethane resin, thermosetting polyimide resin, etc. can be used.

As the bio-derived material, for example, biodissolved substances such as hyaluronic acid, collagen, elastin, and cellulose can be used.
As the metal, for example, stainless steel, cobalt alloy, titanium alloy, etc. can be used, and specific examples thereof include 316L (stainless steel), ASTM F75 (Haynes-Stellite 21: cobalt alloy), ASTM F67 (pure titanium), Materials with corrosion resistance in physiological environments such as ASTM F136 (Ti-6Al-4V: titanium alloy) can be used.
As the ceramic, for example, alumina, zirconia, etc. can be used. Note that ceramics can also be coated on the surfaces of the metals mentioned above in order to avoid the problem of corrosion in metals.

The dimensions of the microneedle 12 are, for example, a base end diameter (base end width: width of the base) on the pedestal 11 side of about 100 μm to 1000 μm, and a height of 0.03 mm to 5.0 mm (preferably, the lower limit is 0.1 mm). , the upper limit is about 2.0 mm), and the radius of curvature of the arc-shaped tip is about 5 μm to 70 μm. Here, the proximal diameter is determined by considering the resistance to breakage (suppressing and even preventing damage), and the height is determined by considering the length that can break through the epidermis of the skin and administer the drug into the dermis. The radius of curvature of the tip is set in consideration of not feeling pain (making it difficult to feel) during use.
In addition, the arrangement pitch of the microneedles 12 on the pedestal 11 means the distance between the closest microneedles 12 among adjacent microneedles 12, and is 0.5 mm or more. It is about .0 mm or less.

Next, microneedle arrays according to first to fourth embodiments of the present invention will be described with reference to FIGS. 1(A) to 1(D).
Each of the microneedle arrays according to the first to fourth embodiments has a large number of microneedles erected on a pedestal 11, like the microneedle array 10 described above. It has microneedles A constituting a microneedle group A standing upright in an inner region, and microneedles B constituting a microneedle group B standing upright in an outer region surrounding the inner region. The microneedle A and microneedle B of each of the microneedle arrays according to the first to fourth embodiments have a height (FIG. 1(A)), a proximal end diameter (FIG. 1(B)), an arrangement pitch ( The shape of the tip (FIG. 1(C)) is different from that of the tip (FIG. 1(D)), and it has excellent puncturing properties. Note that FIGS. 1A to 1D correspond to side views of the microneedle array 10 shown in FIG.
This will be explained in detail below.

The inner region and outer region of the pedestal 11 are regions set based on the results of investigating the puncture depth of the microneedles described above (see FIGS. 4 to 6). To explain the area on the pedestal 11 where the microneedles 12 of the microneedle array 10 shown in FIG. The area ranges from at least the center position P to W x 0.3 (preferably W x 0.5), and the outer area ranges from at least the end position E to W x 0.1 (preferably W x 0.2). ). In addition, in the case of the upright position of the microneedles 12, in the area where the microneedles 12 are upright, the upright position of one row of microneedles 12 located at the outermost periphery, or the position at the outermost periphery and the inner side thereof. The upright positions of the two rows of microneedles 12 correspond to the outer region, and the remaining positions correspond to the inner region.
In this embodiment, an intermediate region is provided between the inner region and the outer region, but the inner region and the outer region may be continuous without interposing the intermediate region. It should be noted that the microneedles C erected in the intermediate region are different in height, base end diameter, arrangement pitch, or tip shape from the microneedles A erected in the inner region. Microneedle B is set (stepwise) to a value between the microneedles B and B.

The microneedle array shown in FIG. 1(A) consists of microneedles (an example of microneedle A) 21 forming a microneedle group (an example of microneedle group A) 20 arranged upright in an inner region, and microneedles (an example of microneedle A) 21 arranged upright in an outer region. The height of the microneedles 23 (an example of microneedles B) constituting the microneedle group (an example of microneedle group B) 22 is different from that of the microneedles 21. It is lower than the height.
Note that the microneedles 21 and 23 and the microneedles 24 (an example of microneedles C) erected in the intermediate region have the same base end diameter and are arranged on the pedestal 11 at the same pitch.

Here, the height difference ΔT between the microneedle 21 and the microneedle 23 is preferably more than 0 μm and 200 μm or less (preferably, the lower limit is 30 μm, more preferably 50 μm, and the upper limit is 170 μm, furthermore 150 μm). Although the heights of the microneedles 21 and 23 are the same, they may be gradually lowered from the center position P side to the end position E side under the above-described conditions.
In this way, by making the height of the microneedles 23 lower than the height of the microneedles 21, the microneedles 21 in the inner region, which tend to penetrate the skin more shallowly than the outer region, are preferentially penetrated into the skin than the microneedles 23. The microneedle array becomes easier to penetrate, the variation in puncture depth can be reduced, and the puncture performance of the microneedle array can be improved. Note that the height of the microneedle 24 is set between the microneedle 21 and the microneedle 23.

The microneedle array shown in FIG. 1(B) consists of microneedles (an example of microneedle A) 31 configuring a microneedle group (an example of microneedle group A) 30 erected in an inner region, and microneedles 31 (an example of microneedle A) erected in an outer region. The microneedles (an example of microneedle B) 33 constituting the installed microneedle group (an example of microneedle group B) 32 have different proximal diameters (also referred to as root diameters or base diameters). The diameter B of the proximal end of the needle 33 is made wider than the diameter A of the proximal end of the microneedle 31.
Note that the microneedles 31 and 33 and the microneedles 34 (an example of microneedles C) erected in the intermediate region have the same height and are arranged on the pedestal 11 at the same pitch.

Here, the diameter of the proximal end of the microneedle 33 is preferably 300 μm or more and 1000 μm or less (preferably, the lower limit is 400 μm, more preferably 500 μm, and the upper limit is 900 μm, and even more preferably 800 μm). Although the diameters of the proximal ends of the microneedles 31 and 33 are the same, they may gradually widen from the center position P side to the end position E side under the above-described conditions.
In this way, by making the proximal diameter of the microneedle 33 wider than the proximal diameter of the microneedle 31, the microneedle 31 in the inner region, which tends to be less likely to stick than the outer region, becomes acutely angled and It is easier to penetrate the skin than the needle 33, and variations in the ease of penetration can be reduced, so the puncture performance of the microneedle array can be improved. Note that the diameter of the proximal end of the microneedle 34 is set between the microneedle 31 and the microneedle 33.

The microneedle array shown in FIG. 1(C) consists of microneedles (an example of microneedle A) 41 that constitute a microneedle group (an example of microneedle group A) 40 that is erected in an inner region, and microneedles (an example of microneedle A) 41 that are erected in an outer region. The arrangement pitches of the microneedles (an example of microneedle B) 43 constituting the microneedle group (an example of microneedle group B) 42 are different from each other, and the arrangement pitch B of adjacent microneedles 43 is The pitch is narrower than the arrangement pitch A of the matching microneedles 41.
Note that the microneedles 41 and 43 and the microneedle 44 (an example of microneedle C) erected in the intermediate region have the same shape. Moreover, the arrangement pitch of microneedles means the distance at the position where adjacent microneedles are closest among a plurality of microneedles arranged in a straight line.

Here, the arrangement pitch A is 1.0 mm or more and 2.0 mm or less (preferably, the lower limit is 1.3 mm and the upper limit is 1.5 mm), and the arrangement pitch B is 0.5 mm or more and 1.0 mm or less (preferably, It is preferable that the lower limit is 0.6 mm and the upper limit is 0.8 mm. The arrangement pitches A and B of the microneedles 41 and 43 are the same, but may be gradually narrowed from the center position P side to the end position E side under the above conditions.
In this way, by making the arrangement pitch B of the adjacent microneedles 43 narrower than the arrangement pitch A of the adjacent microneedles 41, the microneedles 43 in the outer region, which tend to penetrate deeper than the inner region, are It is harder to penetrate the skin than 41, and the variation in puncture depth can be reduced, so the puncturing performance of the microneedle array can be improved. Note that the arrangement pitch C of the adjacent microneedles 44 is set between the arrangement pitch A and the arrangement pitch B.

The microneedle array shown in FIG. 1(D) consists of microneedles (an example of microneedle A) 51 configuring a microneedle group (an example of microneedle group A) 50 erected in an inner region, and microneedles 51 erected in an outer region. The microneedles (an example of microneedle B) 53 constituting the microneedle group (an example of microneedle group B) 52 and the distal end portions of the microneedles 53 are different in shape, and the microneedles 53 have an arc shape. The radius of curvature B of the tip is made larger than the radius of curvature A of the arc-shaped tip of the microneedle 51.
Note that the microneedles 51 and 53 and the microneedles 54 (an example of microneedles C) erected in the intermediate region have the same base end diameter and the same height, and are arranged at the same pitch on the pedestal 11. .

Here, the radius of curvature A of the tip is 5 μm or more and 20 μm or less (preferably, the lower limit is 7 μm and the upper limit is 15 μm), and the curvature radius B is 30 μm or more and 70 μm or less (preferably, the lower limit is 40 μm and the upper limit is 60 μm). It is preferable that there be. Although the radii of curvature A and B of the tips of the microneedles 51 and 53 are the same, they can also be gradually increased from the center position P side to the end position E side under the above-described conditions.
In this way, by making the radius of curvature B of the tip of the microneedle 53 larger than the radius of curvature A of the tip of the microneedle 51, the microneedle 51 in the inner region, which tends to be less likely to stick than the outer region, can It is easier to penetrate the skin than the microneedles 53, and variations in the ease of penetration can be reduced, so the puncture performance of the microneedle array can be improved. Note that the radius of curvature C of the arc-shaped tip of the microneedle 54 is set between the radius of curvature A and the radius of curvature B.

Furthermore, in the above-mentioned microneedle array, as shown in FIG. Microneedles 21, 23, 24, microneedles 31, 33, 34, microneedles 41, 43, 44, and microneedles 51, 53, 54 shown in FIGS. 1 to 4, respectively, are erected).
The cross section of the upper surface of the pedestal 11a has an arcuate shape that projects upward (the side where the microneedles are erected), but it may also be a straight line that slopes downward from the center of the pedestal to the outside. It may also be in the form of steps that gradually become lower from the center of the pedestal to the outside.

Here, the height difference ΔH between the inner region and the outer region of the pedestal 11a is preferably more than 0 μm and 200 μm or less (preferably, the lower limit is 30 μm, preferably 50 μm, and the upper limit is 160 μm, and even 140 μm).
In this way, by making the upper surface height of the inner region of the pedestal 11a higher than the outer region, the microneedles 21, 31, 41, and 51 are preferentially stuck into the skin than the microneedles 23, 33, 43, and 53. This makes it possible to reduce the variation in the ease of puncturing, thereby further improving the puncturing performance of the microneedle array.

The microneedle array described above can be manufactured by injection molding using a metal mold made of hard carbon steel, etc., but it may also be manufactured by pressure molding using a press mold. There are no particular limitations as long as a needle array can be manufactured.

Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the configuration described in the embodiments described above, and the matters described in the claims are as follows. It also includes other embodiments and modifications that may be considered within the scope. For example, a case where the microneedle array of the present invention is constructed by combining some or all of the embodiments and modifications described above is also within the scope of the present invention.
In the embodiment, the microneedles A constituting the microneedle group A erected in the inner region of the pedestal and the microneedles B composing the microneedle group B erected in the outer region have a height of , the base diameter, the arrangement pitch, or the shape of the distal end have been described; however, any two or more of the height, the proximal diameter, the arrangement pitch, and the distal end may be different.

In addition, in the above embodiment, each condition (i.e., any one or more of the height, the width of the base, the arrangement pitch, and the shape of the tip) of the microneedles erected in the intermediate region is It is preferable to set the conditions of the microneedles erected in the area and the outer area so that they are continuous (slope), but the conditions of the microneedles erected in the middle area are set to be the same (for example, at the same height, etc.). ).
Further, in the above embodiment, the inner region has the same width from the center position P toward each side (outer region), but the width can be partially different. have the same width from each side toward the center position P, but may have partially different widths.

The microneedle array according to the present invention can reduce variations in the depth of puncture of microneedles into the skin compared to conventional techniques. This allows a prescribed amount of medicine to be injected under the epidermis, so it can be widely used not only for medication but also for administering beauty serums to the skin and scalp.

10: Microneedle array, 11, 11a: Pedestal, 12: Microneedle, 20: Microneedle group (Microneedle group A), 21: Microneedle (Microneedle A), 22: Microneedle group (Microneedle group B) , 23: Microneedle (Microneedle B), 24: Microneedle (Microneedle C), 30: Microneedle group (Microneedle group A), 31: Microneedle (Microneedle A), 32: Microneedle group (Microneedle Needle group B), 33: Microneedle (Microneedle B), 34: Microneedle (Microneedle C), 40: Microneedle group (Microneedle group A), 41: Microneedle (Microneedle A), 42: Microneedle Needle group (microneedle group B), 43: microneedle (microneedle B), 44: microneedle (microneedle C), 50: microneedle group (microneedle group A), 51: microneedle (microneedle A) , 52: Microneedle group (Microneedle group B), 53: Microneedle (Microneedle B), 54: Microneedle (Microneedle C)

Claims (5)

In a microneedle array in which a large number of microneedles are set up on a pedestal,
When viewed from above, microneedles A constituting microneedle group A are erected in an inner region including the center position of the pedestal, and microneedles A are erected in an outer region surrounding the inner region including the outer peripheral end position of the pedestal. The microneedles B constituting the microneedle group B are as follows:
The width of the base of the microneedle B is wider than the width of the base of the microneedle A, and the tip of the microneedle A is more acute than the tip of the microneedle B, and has excellent puncturing properties. A microneedle array characterized by: The microneedle array according to claim 1, wherein the microneedle A and the microneedle B have the same height. The microneedle array according to claim 1 or 2, wherein the width of the base of the microneedle B is 300 μm or more and 1000 μm or less. 4. The microneedle array according to claim 1, wherein the top surface height of the inner region of the pedestal is higher than the top surface height of the outer region. 5. The microneedle array according to claim 4, wherein the difference in height of the pedestal is more than 0 μm and less than 200 μm.

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