JP2022117769A - microneedle array - Google Patents

Abstract

To provide a microneedle array capable of pouring medicine of a regulated amount under the skin.SOLUTION: In a microneedle array, many microneedles are stood on a pedestal 11, and microneedles 21, 31, 41, 51 composing microneedle groups 20, 30, 40, 50 standing in an inner area of the pedestal 11 in a planar view and microneedles 23, 33, 43, 53 composing microneedle groups 22, 32, 42, 52 standing in an outer region encircling the inner area differ in one or two of height, width of a base part, an arrangement pitch and a shape of an end part, and are excellent in needling performance.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a microneedle array capable of injecting medication into the body in place of, for example, conventionally used syringes.

In the future, as the aging society progresses, the proportion of medical care in the social system will increase. For this reason, for example, as one of the measures to reduce the frequency of hospital visits for the elderly and busy people, and as part of home medical care for remote areas and depopulated areas where doctors and hospitals are scarce, The need for home medication based on a doctor's prescription will grow.
Surgical treatment of affected areas such as trauma and drug therapy account for a large proportion of medical practice, and in drug therapy, intracorporeal administration using a syringe accounts for a large proportion. This syringe administration is usually administered at a hospital by a qualified person such as a doctor or nurse, but in some cases it is permitted for the patient to administer it at home, such as administering insulin for diabetes. Some are

The advantage of administration with a syringe is that it can be administered directly subcutaneously or into a blood vessel, but the disadvantages are pain during injection and scarring (injection marks) and swelling as the number of administrations increases.
Therefore, instead of a syringe, it is considered to use a resin or metal microneedle array having a plurality of microneedles with sharp tips on a pedestal (flat plate) (see, for example, Patent Documents 1 and 2). .
In the use of this microneedle array, the length of the microneedles can be set to a size that can reach the depth of the subcutaneous painless point, thereby eliminating pain during use (achieving painlessness). In addition, since it is used by just applying it to the epidermis in the form of a patch, the patient himself/herself can easily administer the drug at home, thereby greatly reducing the burden on the patient.

JP 2019-111274 A JP 2018-183511 A

However, when a plurality of microneedles are pierced into the skin using the above-described microneedle array, the penetration depth (penetration condition) of each microneedle into the skin varies, and the puncture property deteriorates, resulting in subcutaneous penetration. There was a risk that the prescribed amount of medicine could not be injected. Here, the poor puncture property means that the puncture depth of each microneedle has a large variation, and the puncture property is good (excellent) means that the puncture depth of each microneedle has a small variation. , respectively.

The present invention has been made in view of such 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 a plurality of microneedles of the same shape were erected on a pedestal at the same pitch, and determined the puncture depth of each microneedle. As a result of the investigation, the following findings were obtained.
For the investigation, as shown in FIG. 4, four types of microneedle arrays having different numbers of microneedles arranged on the pedestal were used. Each of these four types of microneedle arrays has 26 microneedles (arrangement pitch: 1.5 to 1.8 mm), 52 (arrangement pitch: 1.3 mm), 100 (arrangement pitch: 0.6 mm). ), and 140 microneedles (arrangement pitch: 0.6 mm) are arranged, and the shape and size of the microneedles constituting each microneedle array are the same. Pig skin was used as an 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 pig skin under the same conditions will be described with reference to FIG.
As shown in FIG. 5, the average puncture depth of the microneedles is the best in the case of 52 out of the 4 types of microneedle arrays (penetrating deeply), and even if it is less than this (26), Also, at most (100, 140), a tendency to decrease was obtained.
Next, the results of investigating the distribution of the puncture depth (height distribution) of the microneedles when four types of microneedle arrays are pressed against the pig skin under the same conditions will be described with reference to FIG. . In addition, FIG. 6 is the result of measuring the puncture depth for each microneedle constituting each microneedle array (for example, 26 points when the number of microneedles is 26), and the higher the value, the more puncture depth is deep (penetrated deeply).
As shown in FIG. 6, for any of the four types of microneedle arrays, the microneedles are biased in the way they stick in the width direction (up and down direction and left and right direction) of the pedestal when viewed from above. The microneedles placed in the outer region surrounding the inner region tended to stick deeper than the microneedles placed in the inner region.

The results obtained from the above knowledge are shown below.
As the number of microneedles increased, the number of microneedles per unit area increased, so the force at the time of puncture was dispersed and the puncture performance deteriorated.
When the number of microneedles was reduced and the arrangement pitch was too wide, the skin between the adjacent microneedles tended to bend, resulting in poor puncture performance.
The puncture depth varied depending on the placement position of the microneedle. That is, the microneedles arranged in the outer region surrounding the inner region were stuck deeper than the microneedles arranged in the inner region of the pedestal in plan view (the inner region was more shallowly stuck). ).
Therefore, the present inventors have conceived that by changing various conditions for each microneedle arrangement region, it is possible to reduce variations in the puncture depth of the microneedles, that is, to improve the puncture performance.
The present invention was made based on the above knowledge, and the gist thereof is as follows.

The microneedle array according to the present invention in line with the above object is a microneedle array in which a large number of microneedles are erected on a pedestal,
In plan view, the microneedles A constituting the microneedle group A erected in the inner region (central region) of the pedestal, and the microneedle group erected in the outer region (peripheral region) surrounding the inner region The microneedles B constituting B differ in one or more of height, base width, arrangement pitch, and tip shape, and have excellent puncture properties.

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

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, on the condition that the shape of the tip is different, the curvature radius B of the arc-shaped tip of the microneedle B is set to the arc-shaped tip of the microneedle A. should be larger than the radius of curvature A of .
Here, it is preferable that the curvature radius 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 upper surface height of the inner region of the pedestal is higher than the upper surface height of the outer region.
Here, the height difference of the pedestal is preferably more than 0 μm and not more than 200 μm.

The microneedle array according to the present invention has a microneedle group A erected in the inner region of the pedestal and a microneedle group B erected in the outer region surrounding the inner region. Since one or more of the width, the arrangement pitch, and the shape of the tip portion are changed, variations in puncture depth (penetration condition) of a plurality of microneedles can be reduced more than before (puncture performance can be improved). ), making it possible to inject a defined amount of 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 explanatory drawing which shows the outline|summary of the same microneedle array. It is a side view of a microneedle array concerning a modification. FIG. 4 is a plan view showing the arrangement of microneedles forming four types of microneedle arrays used in the investigation. It is a graph which shows the relationship between the number of microneedles obtained using the same four types of microneedle arrays, and average puncture depth. It is explanatory drawing which shows the result of having measured the puncture depth of the microneedle which comprises the same four types of microneedle arrays.

Next, with reference to the attached drawings, specific embodiments of the present invention will be described for better understanding of the present invention.
First, using the microneedle array 10 shown in FIG. 2 for the overall outline (common part) of the microneedle arrays according to the first to fourth embodiments of the present invention shown in FIGS. to explain.
The microneedle array 10 is a device (medical device) that administers medication into the body in place of a conventionally used syringe. The application of the microneedle array 10 is not limited to medication, but can also be used for administration of beauty essences to the skin and scalp, collection of skin tissue and body fluids, and the like.

The microneedle array 10 is composed of, for example, a combination of one or more of resins, bio-derived materials, metals, and ceramics (hereinafter also referred to as resins, etc.). It has a plurality of microneedles (also referred to as needles or microneedles) 12 with pointed tips. Note that the entire microneedle array does not necessarily have to be made of resin or the like, and at least the microneedles should be made of resin or the like. In addition, a metal layer can be formed on the surface of the microneedle by 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 a square (or may be a rectangle) in plan view, but is not particularly limited. or face-like.
Moreover, although the shape of the microneedle 12 is conical, it may be, for example, an elliptical pyramid or a polygonal pyramid (a triangular pyramid, a quadrangular pyramid, or the like).

For example, about 10 to 1000 (preferably, the lower limit is 30 and the upper limit is 300) microneedles 12 are arranged upright in the range of about 1 cm ² of the base 11 . Therefore, the size of the pedestal 11 should have an area in which the microneedles 12 can be arranged.
Here, the arrangement area on the pedestal 11 of the plurality of microneedles 12 is a square in plan view, but may be, for example, a rectangle, a circle, an ellipse, or a polygon. A circle has a diameter, an ellipse has a major axis, and a polygon (regular polygon) has a side of, for example, about 5 to 50 mm. Note that the short sides of the rectangle can be appropriately set to be shorter than the long sides.
Moreover, although each microneedle 12 is arrange|positioned at the base 11 at planar view in the shape of a grid, for example, it can also be arrange|positioned at random or staggered. Here, dispersing in a staggered manner means that in a plurality of rows in which the microneedles are arranged linearly at regular intervals (standing), between adjacent rows, the microneedles in one row are arranged in the other row It refers to a state in which the microneedles are placed (upright) at a position corresponding to the center of the gap between the adjacent microneedles.

Since the microneedle 12 is a portion for administering medicine to the human body, grooves, depressions, or the like can be formed on the surface side of the microneedle 12 as necessary. through holes) can also be formed.
The shape, size, and number of the microneedles 12, and the manner and range of arrangement of the microneedles 12 on the pedestal 11 are determined by the application 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 employ the shape described in Patent Document 1, Patent Document 2, and the like. This microneedle is bifurcated on the tip side (puncture portion), and is capable of holding a drug in a concave portion formed between them.

As the resin constituting the microneedle array 10, for example, a biodegradable plastic (biodegradable resin), a thermoplastic resin, or a thermosetting resin can be used.
Biodegradable plastics are plastics that are decomposed by microorganisms, and examples thereof include polylactic acid, polycaprolactone, polyhydroxyalkanoate, polyglycolic acid, modified polyvinyl alcohol, casein, modified starch, etc. Polylactic acid is particularly preferred. . This polylactic acid is made from corn and has the characteristic of being decomposed into carbon dioxide and oxygen in the human body or in the natural environment. Therefore, by making the microneedle made of polylactic acid, even if the microneedle breaks in the body, it will be decomposed and absorbed in the body, which is safe for the human body.

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

Examples of biomaterials that can be used include substances that dissolve in vivo, such as hyaluronic acid, collagen, elastin, and cellulose.
Examples of metals that can be used include stainless steel, cobalt alloys, titanium alloys, 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) are available.
As the ceramic, for example, alumina, zirconia, or the like can be used. Ceramics can also be coated on the surfaces of the metals described above to avoid corrosion problems in the metals.

The dimensions of the microneedle 12 are, for example, a base end diameter (base end width: base width) 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 arcuate tip is about 5 μm to 70 μm. Here, the proximal diameter takes into account the resistance to breakage (suppressing or even preventing damage), and the height takes into account the length that can break the epidermis of the skin and allow administration to the dermis. The radius of curvature of the tip is set in consideration of not causing pain (making it difficult to feel pain) during use.
Further, the arrangement pitch of the microneedles 12 on the pedestal 11 means the distance between the closest microneedles 12 among the adjacent microneedles 12, as shown in FIG. 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 erected in an inner region, and microneedles B constituting a microneedle group B erected in an outer region surrounding the inner region. The microneedles A and microneedles B of each of the microneedle arrays according to the first to fourth embodiments have a height (FIG. 1(A)), a base end diameter (FIG. 1(B)), and an arrangement pitch ( Fig. 1 (C)) and the shape of the tip (Fig. 1 (D)) are different, and the penetrability is excellent. 1A to 1D correspond to side views of the microneedle array 10 shown in FIG.
A detailed description will be given below.

The inner region and the outer region of the pedestal 11 are regions set based on the results of the investigation of the puncture depth of the microneedles (see FIGS. 4 to 6). Explaining the region on the pedestal 11 on which the microneedles 12 of the microneedle array 10 shown in FIG. The area ranges from at least the central position P to W×0.3 (preferably W×0.5), and the outer area ranges from at least the end position E to W×0.1 (preferably W×0.2 ). In addition, when the standing position of the microneedles 12 is described, in the region where the microneedles 12 are standing, the standing position of one row of microneedles 12 located on the outermost periphery, or the outermost periphery and the inside thereof The standing position of the two rows of microneedles 12 corresponds to the outer region, and the rest is the inner region.
Although the intermediate region is provided between the inner region and the outer region in the present embodiment, the inner region and the outer region may be continuous without the intermediate region. In addition, 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. It is set to a numerical value between microneedles B (stepwise).

The microneedle array shown in FIG. 1(A) includes microneedles (an example of microneedles A) 21 constituting a microneedle group (an example of microneedle group A) 20 erected in the inner region, and microneedles (an example of microneedles A) 21 standing in the outer region. The height of the microneedles (an example of the microneedles B) 23 constituting the provided microneedle group (an example of the microneedle group B) 22 is different. lower than the height.
The microneedles 21 and 23 and the microneedles (an example of the microneedles C) 24 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 microneedles 21 and 23 is 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, more preferably 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 conditions.
By making the height of the microneedles 23 lower than the height of the microneedles 21 in this way, the microneedles 21 in the inner region, which tend to penetrate more shallowly than the outer region, preferentially penetrate the skin over the microneedles 23. It becomes easier to stick into the microneedle array, variation in puncture depth can be reduced, and the puncture property of the microneedle array can be improved. The height of the microneedle 24 is set between the microneedle 21 and the microneedle 23 .

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

Here, the base end diameter of the microneedles 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, more preferably 800 μm). Although the base end diameters of the microneedles 31 and 33 are the same, they may be gradually widened from the center position P side to the end position E side under the above conditions.
By making the base end diameter of the microneedle 33 wider than the base end diameter of the microneedle 31 in this manner, the microneedle 31 in the inner region, which tends to be less likely to be stuck than in the outer region, has a sharp angle, thereby The microneedle array can be more easily stuck into the skin than the needle 33, and variations in the ease of sticking can be reduced, so that the puncture properties of the microneedle array can be improved. Note that the base end diameter of the microneedle 34 is set between the microneedle 31 and the microneedle 33 .

The microneedle array shown in FIG. 1(C) includes microneedles (an example of microneedles A) 41 constituting a microneedle group (an example of microneedle group A) 40 erected in the inner region, and microneedles (an example of microneedles A) 41 standing in the outer region. The arrangement pitch is different between the microneedles (an example of the microneedles B) 43 constituting the provided microneedle group (an example of the microneedle group B) 42, and the arrangement pitch B of the adjacent microneedles 43 It is narrower than the arrangement pitch A of the matching microneedles 41 .
The microneedles 41 and 43 and the microneedle (an example of the microneedle C) 44 erected in the intermediate region have the same shape. In addition, the arrangement pitch of microneedles means the distance at the position where adjacent microneedles are closest among a plurality of linearly arranged microneedles.

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). Although the arrangement pitches A and B of the microneedles 41 and 43 are the same, they may be gradually narrowed from the center position P side to the end position E side under the above conditions.
By making the arrangement pitch B of the adjacent microneedles 43 narrower than the arrangement pitch A of the adjacent microneedles 41 in this manner, the microneedles 43 in the outer region, which tend to penetrate deeper than in the inner region, are more likely to penetrate the microneedles. It is more difficult to stick into the skin than 41, and variations in puncture depth can be reduced, so the puncture performance of the microneedle array can be improved. In addition, the arrangement pitch C of the adjacent microneedles 44 is set between the arrangement pitch A and the arrangement pitch B. As shown in FIG.

The microneedle array shown in FIG. 1(D) includes microneedles (an example of microneedles A) 51 constituting a microneedle group (an example of microneedle group A) 50 erected in the inner region, and microneedles (an example of microneedles A) 51 standing in the outer region. The shape of the tip portion is different from the microneedle (an example of the microneedle B) 53 that constitutes the provided microneedle group (an example of the microneedle group B) 52, and the microneedle 53 has an arc shape. The curvature radius B of the tip portion is made larger than the curvature radius A of the arcuate tip portion of the microneedle 51 .
The microneedles 51 and 53 and the microneedles (an example of the microneedles C) 54 erected in the intermediate region have the same base end diameter and height, and are arranged on the pedestal 11 at the same pitch. .

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). Preferably. Although the curvature radii A and B of the tip portions of the microneedles 51 and 53 are the same, they can be gradually increased from the center position P side to the end position E side under the above conditions.
Thus, by making the curvature radius B of the tip of the microneedle 53 larger than the curvature radius A of the tip of the microneedle 51, the microneedle 51 in the inner region, which tends to be more difficult to stick than the outer region, The microneedles 53 are easier to stick into the skin than the microneedles 53, and variations in the ease of sticking can be reduced, so the puncture properties of the microneedle array can be improved. The radius of curvature C of the arcuate distal end portion of the microneedle 54 is set between the radius of curvature A and the radius of curvature B. As shown in FIG.

Further, in the microneedle array described above, as shown in FIG. 3, a pedestal 11a in which the upper surface height of the inner region is higher than the upper surface height of the outer region can be used (that is, on the pedestal 11a, the above-described Microneedles 21, 23, 24, microneedles 31, 33, 34, microneedles 41, 43, 44, and microneedles 51, 53, 54 shown in FIGS. 1 to 4 are erected).
The cross-section of the upper surface of the pedestal 11a has an arcuate shape that protrudes upward (on the side where the microneedles are erected), but it may be a straight line that slopes downward from the central portion of the pedestal toward the outside. A stepped shape that gradually lowers from the central portion of the pedestal to the outside may be used.

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, further 50 μm, and the upper limit is 160 μm, furthermore 140 μm).
Thus, by making the upper surface height of the inner region of the pedestal 11a higher than that of the outer region, the microneedles 21, 31, 41, 51 preferentially penetrate the skin over the microneedles 23, 33, 43, 53. Since it becomes easy to stick and the variation in stickability can be reduced, the stickability of the microneedle array can be further improved.

The above-described microneedle array can be manufactured by injection molding using a metal mold made of hard carbon steel or the like, for example. It is not particularly limited as long as a needle array can be manufactured.

The present invention has been described above with reference to the embodiments, but the present invention is not limited to the configurations described in the above embodiments, and the matters described in the claims. It also includes other embodiments and variations that are possible within its scope. For example, the scope of rights of the present invention includes the case where the microneedle array of the present invention is configured by combining some or all of the respective embodiments and modifications described above.
In the above embodiment, the microneedles A constituting the microneedle group A erected in the inner region of the pedestal and the microneedles B constituting the microneedle group B erected in the outer region of the pedestal have a height of , base end diameter, arrangement pitch, or tip shape are different, but two or more of the height, base end diameter, arrangement pitch, and tip end may be different.

In the above-described embodiment, each condition of the microneedles erected in the intermediate region (that is, any one or more of the height, width of the base, arrangement pitch, and shape of the tip) is It is preferable to set each condition of the microneedles erected in the region and the outer region so as to be continuous (gently), but each condition of the microneedles erected in the intermediate region is the same (e.g., the same height, etc.) ).
Furthermore, in the above-described 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. has the same width from each side toward the center position P, but the width can be partially different.

Advantageous Effects of Invention The microneedle array according to the present invention can reduce variations in depth of puncture of the microneedles into the skin as compared with the conventional technique. As a result, a prescribed amount of medicine can be injected under the epidermis, so that it can be widely used not only for drug administration but also for administration of beauty essences to the skin and scalp.

10: microneedle array, 11, 11a: pedestal, 12: microneedle, 20: microneedle group (microneedle group A), 21: microneedle (microneedle group 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 (micro Needle group B), 33: microneedle (microneedle B), 34: microneedle (microneedle C), 40: microneedle group (microneedle group A), 41: microneedle (microneedle A), 42: micro 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 (11)

In a microneedle array in which a large number of microneedles are erected on a pedestal,
In plan view, the microneedles A constituting the microneedle group A erected in the inner region of the pedestal, and the microneedles B constituting the microneedle group B erected in the outer region surrounding the inner region are , the height, the width of the base, the pitch of the arrangement, and the shape of the tip, or any one or more of them, and has excellent puncture properties. 2. The microneedle array according to claim 1, wherein the height of said microneedles B is made lower than the height of said microneedles A on condition that said heights are different. 3. The microneedle array according to claim 2, wherein the height difference between the microneedles A and the microneedles B is more than 0 μm and 200 μm or less. 2. The microneedle array according to claim 1, wherein the width of the base of the microneedle B is made wider than the width of the base of the microneedle A on the condition that the width of the base is different. . 5. The microneedle array according to claim 4, wherein the width of the base of the microneedle B is 300 μm or more and 1000 μm or less. 2. The microneedle array according to claim 1, wherein the arrangement pitch B of the adjacent microneedles B is narrower than the arrangement pitch A of the adjacent microneedles A on condition that the arrangement pitches are different. microneedle array. 7. The microneedle array according to claim 6, wherein said arrangement pitch A is 1.0 mm or more and 2.0 mm or less, and said arrangement pitch B is 0.5 mm or more and 1.0 mm or less. In the microneedle array according to claim 1, on the condition that the shape of the tip is different, the curvature radius B of the arc-shaped tip of the microneedle B is set to the arc-shaped tip of the microneedle A. A microneedle array characterized by being larger than the radius of curvature A of the part. 9. The microneedle array according to claim 8, wherein the curvature radius 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. 10. The microneedle array according to any one of claims 1 to 9, wherein the height of the upper surface of the inner region of the pedestal is higher than the height of the upper surface of the outer region. 11. The microneedle array according to claim 10, wherein the height difference of said pedestal is more than 0 [mu]m and not more than 200 [mu]m.

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