WO2018092424A1 - Microneedle - Google Patents

Abstract

The purpose of the present invention is to provide a microneedle, the tip of which reliably passes through the epidermis and reaches the hypodermis when puncturing the skin so as to be able to supply a medicine and the like to the hypodermis or a region deeper than the hypodermis, and which is capable of causing the medicine and the like to remain in the hypodermis or a region deeper than the hypodermis. Accordingly, this microneedle (10, 110) has a tip portion (2, 102), the tip of which has a sharp cone or pyramid shape, and a base (1) having a truncated cone or pyramid shape, a step portion (S1, S2) being formed at the boundary between the base side end portion of the tip portion (2, 102) and the tip portion side end portion of the base (1).

Description

Micro needle

The present invention relates to a microneedle.

In recent years, microneedles have rapidly spread as a technology for supplying drugs, cosmetics, and other substances that contribute to the activity of the skin (hereinafter referred to as “medicine etc.”) to the skin surface easily and reliably. .
Here, in order to activate the skin, particularly the epidermis by supplying chemicals or the like with the microneedle, when the microneedle is punctured into the skin, the tip surely penetrates the epidermis and reaches the dermis. Need to be supplied with chemicals.

However, as shown in FIG. 10, the conventional microneedle indicated by reference sign P1 punctures the skin only about 60 μm (region A) from the tip, for example. For the region B on the dermis T side (the lower region in FIG. 10: the region separated from the surface Su), the skin tissue is only crushed by the microneedle P1, and the tip of the microneedle P1 is the skin. It does not penetrate inside. Therefore, the conventional microneedle P1 only supplies chemicals etc. to a part of the stratum corneum Uh in the epidermis U (that is, the stratum corneum Uh constitutes a part of the epidermis U), and supplies chemicals etc. to the dermis T. Could not be activated.
Therefore, it has been difficult to activate the skin to a desired level.

Further, in the conventional microneedle, when the needle is pulled out after puncturing, the microneedle is pulled out from the skin, and there is a possibility that the medicine does not remain in the skin. In order to activate the skin, it is desirable that a part of the microneedle remains in the skin when it is pulled out from the skin. However, with a conventional microneedle, it is not possible to leave a part of the microneedle on the skin after puncturing. It was difficult.
As another conventional technique, there is a microneedle having a sharp frustoconical tip (see Patent Document 1), but even if the tip passes through the stratum corneum, for the same reason as described above. It is difficult to penetrate the epidermis. In addition, the chemicals constituting the microneedle cannot be efficiently left in the skin.

Japanese Patent No. 5050130

The present invention has been proposed in view of the above-described problems of the prior art. When the skin is punctured, the tip surely penetrates the epidermis and reaches the dermis, and the dermis or a deeper region (skin surface) It is an object of the present invention to provide a microneedle capable of supplying a medicine or the like to a region separated from the dermis and allowing the medicine or the like to remain in a dermis or a deeper region.

The microneedle (10, 110) of the present invention has a conical shape or a pyramid shape (triangular pyramid, quadrangular pyramid, pentagonal or higher polygonal pyramid) with a sharp tip, a truncated cone shape or a truncated pyramid shape (triangular shape). A base (1) having a truncated cone shape, a quadrangular frustum shape, or a pentagonal or more polygonal truncated pyramid shape, and a base side end portion of the tip portion (2, 102) and a tip side end portion of the base (1). A step (S1, S2) is formed at the boundary.
Here, the tip angle (θ1) of the tip portions (2, 102) and the angle (θ2) of the tip side end portion of the base (1) are both preferably less than 14 °.
In the present invention, the microneedle (10, 110) is a drug or the like, for example, hyaluronic acid (including low molecular hyaluronic acid, hyaluronic acid not corresponding to low molecular hyaluronic acid), hair restorer, and supernatant of a culture solution in which stem cells are cultured. In addition, it is preferable to be composed of other materials (materials for producing microneedles) that can give activity to the skin, insulin. The material is preferably a liquid and solidifiable material.
In addition, drugs as materials for microneedle production include anticancer agents, hair restorers, hearing loss treatment agents, allergy (eg “hay fever”) treatment agents, purulent treatment agents, Alzheimer's disease and other cognition Drugs for diseases, drugs for brain diseases, drugs for treating oral inflammation, drugs for periodontal disease, drugs for alveolar bone regeneration, drugs for oral immunity factories, drugs for sunburn prevention and inflammation treatment by sunburn, Drugs for the treatment of psoriasis, drugs for the treatment of atopic dermatitis, drugs for the treatment of acne (bed sores), drugs for the treatment of various other skin diseases, drugs for the regeneration of the skin to remove the pregnancy line, It includes a wide variety of other drugs (for example, traditional Chinese medicines) such as wounds and other post-surgical skin regenerative drugs, drugs for treating diseases caused by ringworms, puncture augmentation and ED prevention drugs. In addition, the drug or the like as a material for manufacturing the microneedle is intended to encompass not only human drugs but also drugs for animals such as dogs, cats and livestock.
The microneedle (10, 110) of the present invention has no space inside (so-called “solid”). However, it is also possible to have a space inside (so-called “hollow”).

In the microneedle (110) of the present invention, a taper that is inclined in the distal direction from the radially outer side to the inner side is formed at the base side end of the distal end portion (102). It is preferable that the cross-sectional shape is formed in an arrowhead shape.

The manufacturing method of the microneedle (10) of the present invention includes a manufacturing process of manufacturing a microneedle (10A) having a conical shape or a pyramid shape (triangular pyramid, quadrangular pyramid, pentagonal or higher polygonal pyramid) in advance,
A liquid material for producing microneedles (the above-mentioned drug) on a mold (20) (with a plurality of recesses (20A)) having a conical shape or a pyramid shape (triangular pyramid, quadrangular pyramid, pentagonal or higher polygonal pyramid). Etc.)
A partial removal step of removing a portion of the filled liquid material (eg, by a so-called “squeegee”);
A tip insertion step of inserting (inserting) the tip of the microneedle (10A) manufactured in advance into the material remaining in the recess (20A) of the mold (20), and holding in that state;
It is characterized by having an extraction step of taking out the microneedle (10A) when the material remaining in the recess (20A) of the mold (20) is solidified.

According to the microneedle (10, 110) of the present invention having the above-described configuration, the tip (2, 102) of a conical shape or a pyramid shape (triangular pyramid, quadrangular pyramid, pentagonal or higher polygonal pyramid) is sharply ( For example, since the tip angle θ1 is less than 14 °, the skin tissue can be incised by the sharp tip (2, 102). And when the front-end | tip part (2,102) incises skin tissue, the base (1) can also penetrate | invade easily into skin tissue.
Therefore, the microneedles (10, 110) penetrate into the dermis (T), for example, and chemicals or the like that are the material forming the microneedles (10, 110) are supplied (for example, to the dermis T), and the skin is activated. Turn into.

Then, after the tip (2, 102) of the microneedle (10, 110) reaches the dermis (T), for example, if the microneedle (10, 110) is pulled out of the skin, the tip (2, 102) Since the stepped portions (S1, S2) formed at the boundary between the base side end of the base and the tip side end of the base (1) engage with the skin tissue, the microneedle is pulled out. Then, due to the force for pulling out the microneedles (10, 110), stress concentration occurs in the stepped portions (S1, S2), and the tip portions (2, 102) and the base (1) are divided. Therefore, only the base (1) of the microneedle (10, 110) is pulled out of the skin tissue, and the tip (2, 102) remains in the skin (for example, when it reaches the dermis T).
Here, since the tip portion (2, 102) is also formed of a medicine or the like, the tip portion (2, 102) remains on the skin, so that the medicine or the like is continuously supplied to the skin tissue. The medicinal effect is continuously exhibited over a long period of time.

In the present invention, a taper that inclines in the distal direction from radially outward to inward is formed at the base side end of the distal end portion (102), and the cross-sectional shape of the distal end portion (102) is an arrowhead shape If formed, when the microneedle (110) is pulled out after entering the skin, the protruding portion of the base side end (the rear end of the arrowhead) of the arrowhead tip (102) pierces the skin tissue. It becomes even more difficult to escape from the skin.
Therefore, the tip portion (102) of the microneedle (110) is reliably left in the skin, and the effect that the medicinal effect is continuously exerted over a long period of time is more satisfactorily exhibited.

The microneedle (10) of the present invention described above has a stepped portion (S1) formed at the boundary between the base side end of the tip (2) and the tip side end of the base (1). Even when a concave portion having a shape complementary to the microneedle (10) of the present invention is formed in a mold and the concave portion is filled with a liquid material and solidified, the stepped portion (S1) becomes a resistance, and the solidified microneedle (10 ) Cannot be pulled out of the recess.
On the other hand, according to the manufacturing method of the present invention, after filling the mold (20) (the concave portion 20A) with the liquid material for manufacturing the microneedle (the above-mentioned medicine or the like) (for example, by so-called “squeegee”) Part of the filled liquid material is removed, and the tip of the microneedle (10A) manufactured in advance is inserted (inserted) into the material remaining in the recess (20A) of the mold (20), and held in that state. After the remaining material is solidified, a stepped portion (S1) is formed at the boundary between the tip (2) and the base (1) by taking out a pre-manufactured conical or pyramidal microneedle (10A). Even the microneedle (10) having it can be easily extracted from the mold (20).

Furthermore, according to the manufacturing method of the microneedle (10) of this invention, the sheet-like member which fixed many microneedles can be manufactured easily.
And by joining the said sheet-like members, the sheet | seat of the large area to which many microneedles was fixed is manufactured, By processing such a large area sheet | seat suitably, each user's use site | part ( For example, it is possible to provide a device adapted to the shape of the hair portion (so-called “custom-made”).

It is a front view which shows the microneedle which concerns on 1st Embodiment of this invention. It is a figure which shows the effect | action of the microneedle which concerns on 1st Embodiment, Comprising: It is explanatory drawing which shows the state punctured to skin. It is a figure which shows the effect | action of the microneedle which concerns on 1st Embodiment, Comprising: It is explanatory drawing which shows the state which extracted the microneedle punctured to skin. It is a flowchart which shows the manufacturing method of the microneedle which concerns on 1st Embodiment. It is explanatory sectional drawing which shows 1 process of the manufacturing method of the microneedle which concerns on 1st Embodiment. It is explanatory sectional drawing which shows the process after the process shown in FIG. It is explanatory sectional drawing which shows the process after the process shown in FIG. FIG. 8 is an explanatory cross-sectional view showing a step that follows the step shown in FIG. 7. It is a front view which shows the microneedle which concerns on 2nd Embodiment of this invention. It is a schematic diagram which shows the outline | summary of a prior art.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
In the accompanying drawings, the scale is not the same for ease of illustration, and the ratio of each part is expressed differently for each drawing.
First, the microneedle 10 according to the first embodiment will be described with reference to FIGS. 1 to 3.

In FIG. 1, a microneedle generally indicated by reference numeral 10 has a distal end portion 2 and a base 1.
The shape of the tip 2 is a conical shape with a sharp tip (the upper end side of the tip 2 in FIG. 1), and the shape of the base 1 is a truncated cone. The shape of the tip 2 may be a pyramid (triangular pyramid, quadrangular pyramid, pentagonal or higher polygonal pyramid) instead of a conical shape. The shape of the base 1 may be a truncated pyramid (triangular truncated cone, quadrangular truncated pyramid, pentagonal or more polygonal truncated pyramid) instead of the truncated cone.
The height dimension H (vertical dimension in FIG. 1) of the base 1 is set as a dimension sufficient for the distal end portion 2 to reach the dermis T when the microneedle 10 is punctured into the skin. And the height dimension Ht (vertical direction dimension in FIG. 1) of the front-end | tip part 2 is set to a dimension sufficient for the front-end | tip part 2 to supply a chemical | medical agent to the dermis T. FIG.

At the boundary between the base end of the tip 2 of the microneedle 1 (the lower end of the tip 2 in FIG. 1) and the end of the base 1 (the upper end of the base 1 in FIG. 1) A step S1 (shoulder at the tip 2) is formed. As will be described later with reference to FIG. 3, when the microneedle 10 is pulled out after being punctured into the skin, the stepped portion S1 (shoulder portion at the distal end portion 2) becomes resistance when pulled out from the skin tissue, and stress concentration occurs at the stepped portion S1. And the tip 2 remains in the skin tissue.
In FIG. 1, the tip angle θ1 of the tip portion 2 formed in a conical shape and the angle θ2 of the tip side end portion of the base 1 formed in a truncated cone shape are both set to be less than 14 ° (θ1 < 14 ° and θ2 <14 °).
Here, when the tip angle θ1 of the tip 2 and the angle θ2 of the tip side end of the base 1 are 14 ° or more, the tip 2 is difficult to reach the dermis T when the microneedle 10 is punctured into the skin. This has been confirmed by the inventor.

The bottom surface portion 1B on the lower side of the base 1 has a rapidly increasing diameter.
When a large number of microneedles 10 are attached to the same sheet (a set of sheet-like members, not shown), they are stuck to the sheet-like member (not shown) obtained by applying an adhesive to each manufactured microneedle 10. Then, when storing, by increasing the diameter of the bottom surface portion 1B, the bottom surface portion 1B is reliably adhered to the sheet-like member. Here, the maximum diameter of the bottom surface portion 1B (diameter at the lower end portion) is indicated by symbol DB.
However, it is possible to omit the base bottom surface portion 1B (the portion where the diameter is rapidly increased).

The microneedle 10 is manufactured in the form described later. At that time, examples of the molding material include hyaluronic acid (including low molecular hyaluronic acid and hyaluronic acid not corresponding to low molecular hyaluronic acid), hair restorer, Any material can be selected as long as it is a material capable of imparting activity to the supernatant of the culture medium in which the stem cells are cultured or other skin.
The material is in a liquid phase, and is solidified by cooling the molding material or removing moisture during molding. As an aspect for removing moisture, for example, the molding material can be heated to evaporate the moisture, or the pressure can be reduced to evaporate the moisture.

In the first embodiment, in the microneedle 10, the distal end portion 2 and the base 1 are not hollow but have a so-called “solid” shape.
Since the microneedle 10 is made of a material capable of imparting activity to the skin, when the microneedle 10 reaches the dermis T, the dermis T (or the entire skin) can be activated by the microneedle 10 itself. . Therefore, it is not necessary to form a conduit inside the microneedle like an injection needle and to inject a material capable of giving activity to the skin into the dermis T through the conduit.
Further, in the case where the microneedle 10 is configured in a circular tube shape with metal like the injection needle, if the microneedle 10 is broken when entering the skin tissue, there is a possibility that the metal may remain in the skin tissue. . In order to prevent such a situation, in the illustrated embodiment, a metal is not selected as the material of the microneedle 10, and the microneedle 10 is not formed in a hollow circular tube shape (injection needle shape).
However, it is also possible to comprise the front-end | tip part 2 and the base 1 in a hollow shape.

The operation of the microneedle 10 shown in FIG. 1 will be described with reference to FIGS.
In FIG. 2, when the microneedle 10 is punctured into the skin, the tip 2 of the microneedle 10 is formed in a sharp conical shape (tip angle θ1 <14 °), so that the tip 2 can easily incise skin tissue. And penetrates through the stratum corneum Uh and easily reaches the dermis T. As shown in FIG. 2, most of the distal end portion 2 penetrates into the dermis T, and the base 1 also penetrates into the stratum corneum Uh.
In this state, chemicals or the like that are the materials forming the microneedle 10 (materials that can give activity to the skin: hyaluronic acid, hair restorer, supernatant of the culture medium in which stem cells are cultured, etc.) are dermis T, etc. The skin is activated.

As shown in FIG. 2, if the microneedle 10 is pulled out after the tip 2 of the microneedle 10 reaches the dermis T (arrow F direction: FIG. 2), the step S1 (shoulder) in the tip 2 is It abuts against the skin tissue and acts as a resistance against the microneedle 10 being pulled out of the skin. As a result, the force for pulling out the microneedle 10 is concentrated on the step S1 (shoulder) and stress concentration occurs, and the microneedle 10 is in the step S1 (shoulder) portion, that is, the tip 2 and the base. The tear occurs at the boundary SD of 1.
When the microneedle 10 is torn at the boundary portion SD between the distal end portion 2 and the base 1, as shown in FIG. 3, the portion on the skin surface side (mainly the base 1) from the torn portion SD of the microneedle 10 is outside the skin. Extracted. On the other hand, a portion (mainly the distal end portion 2) on the distal end side from the rupture portion SD remains in the dermis T (including part of the stratum corneum Uh).
Since the tip side of the tearing portion SD (shoulder portion S1) remains in the skin (particularly in the dermis T), the drug constituting the microneedle 10 remains in the skin (particularly in the dermis T). The medicinal effect of the drug constituting is efficiently exhibited over a long period of time.

A method for manufacturing the microneedle 10 according to the first embodiment will be described with reference to FIGS.
In FIG. 4 which is a flowchart of the manufacturing method of the microneedle 10, a conical microneedle 10A (see FIG. 7) is manufactured in step S0. The microneedle 10A is formed with a tip angle θ2 of less than 14 °. The microneedle 10 </ b> A manufactured in step S <b> 0 is a part constituting the base 1 (tip angle θ <b> 2, height dimension H: see FIG. 1) in the microneedle 10 of the first embodiment, as will be described later.
The microneedle 10 </ b> A is not clearly illustrated, but is manufactured by applying a conventionally known manufacturing method. That is, a mold (not shown) is used, and the mold is filled with a liquid material (such as a drug) for producing microneedles and solidified. After solidification, the conical microneedle 10A is manufactured by taking out the molded microneedle 10A from the mold. After step S0, the process proceeds to step S1.

In step S1 of FIG. 4, as shown in FIG. 5, each of the conical recesses 20A formed in the mold 20 is filled with a liquid material M (medicine etc.) for producing microneedles (material filling step). . The filling of the liquid material M (medicine etc.) is performed to the extent that the liquid material M rises from the top surface of the conical recess 20A due to the surface tension of the liquid material M (medicine etc.).
In the manufacturing process shown in FIGS. 5 to 8, a large number of microneedles (only three are shown in FIGS. 5 to 8) are simultaneously manufactured by the microneedle mold 20. Of course, it is also possible to manufacture each single microneedle.
The conical recess 20A of the mold 20 is configured to have a conical complementary shape with a tip angle θ1 (see FIG. 1) of less than 14 °. In other words, the recess 20A is formed so that the tip angle θ1 (see FIG. 1) of the microneedle 10B (FIG. 8) formed through the steps of FIGS. 6 to 8 is less than 14 °. The microneedle 10 </ b> B (see FIG. 8) is a portion constituting the tip 2 (tip angle θ <b> 1, height dimension Ht: see FIG. 1) of the microneedle 10.

In step S2 of FIG. 4, as shown in FIG. 6, before the liquid material M filled in the conical recesses 20A (20A1 to 20A3) is solidified, a part of the filled liquid material M is dedicated. Remove with spatula PA (so-called “squeegee”) (partial removal step).
In the partial removal process shown in FIG. 6, the dedicated spatula PA is moved so as to wipe the liquid material M at the opening end (upper end in FIG. 6) of the conical recess 20A filled with the liquid material M (arrow C). This is executed by moving the spatula PA in the direction). By moving the spatula PA, a part of the liquid material M filled in the recesses 20A1 and 20A2 is removed.
In the state shown in FIG. 6, the partial removal of the liquid material M in the recesses 20A1 and 20A2 is completed, and the recess 20A3 is filled to the extent that the liquid material M swells. Is executed.

Next, in step S3 of FIG. 4, as shown in FIG. 7, the tip of the microneedle 10A manufactured in advance in step S0 is inserted into the liquid material M (medicine etc.) remaining in the recess 20A of the mold 20 ( Insertion), and hold the tip of the microneedle 10A inserted (tip insertion step).
The tip insertion step is executed before the liquid material M remaining in the recess 20A is not completely solidified.
In step S3, the operation of holding the tip of the microneedle 10A inserted in the liquid material M remaining in the recess 20A can be executed by applying a conventionally known fixing and supporting device.

In step S3, when a predetermined time elapses after the tip of the microneedle 10A is inserted into the recess 20A, the liquid material M (medicine or the like) remaining in the recess 20A of the mold 20 is solidified.
In step S4 of FIG. 4, it is determined whether or not the liquid material M (medicine or the like) remaining in the recess 20A of the mold 20 has solidified.
If solidification of the liquid material M is completed (step S4 is “Yes”), the process proceeds to step S5. If solidification of the liquid material M is not completed (step S4 is “No”), the process returns to step S4 (step S4 is “No”). ”Loop).

When the liquid material M is solidified with the tip of the microneedle 10A inserted into the liquid material M (medicine or the like) remaining in the recess 20A of the mold 20, the microneedle 10A and the microneedle 10B solidified in the recess 20A (FIG. 8). Are integrated to form the microneedle 10 of the first embodiment. The illustration of the subsequent finishing is omitted.
In step S5 of FIG. 4, as shown in FIG. 8, the microneedle 10 formed from the recess 20A of the mold 20 is taken out (in the direction of arrow D) (takeout step).

In the illustrated first embodiment, when the microneedle 10A is manufactured in step S0, a mold different from the mold 20 of FIGS. 5 to 8 is used. It can also be manufactured.
In that case, it is necessary to provide a portion complementary to the inner diameter enlarged portion corresponding to the bottom surface portion 1B of the microneedle 10 in the vicinity of the opening of the mold 20. Even in this case, the tip angle θ1 of the tip 2 of the microneedle 10 and the tip angle θ2 of the base 1 are the same angle, and are set to an angle of less than 14 °.

According to the conventional manufacturing method in which the liquid material is filled in the concave portion of the mold and the liquid material is solidified, the microneedle 10 according to the first embodiment has the stepped portion S1 (shoulder portion) of the distal end portion 2. Since it is caught on the shoulder, it cannot be removed from the mold.
On the other hand, according to the manufacturing method described above, after filling the recess 20A of the mold 20 with the liquid material M (medicine or the like) for microneedle manufacture, a part of the filled liquid material M is removed, and the mold 20 The tip of a conical or pyramidal microneedle 10A manufactured in advance is inserted into the material M remaining in the recess 20 and held in this state. After the remaining material M is solidified, the microneedle 10A is taken out. . Therefore, even if the microneedle 10 has the stepped portion S1 at the boundary between the distal end portion 2 and the base 1, the stepped portion S1 can be easily extracted from the mold 20 without being caught by the mold 20.

In addition, since the microneedle 10 according to the first embodiment can be manufactured using the mold 20, a sheet-like member to which a large number of microneedles 10 are fixed can be easily manufactured.
And by joining the said sheet-like members, the sheet | seat of a large area to which many microneedles 10 were fixed is manufactured, and the use site | part of each user by processing such a large area sheet | seat suitably It is possible to provide a device adapted to the shape of the hair (for example, the hair portion) in a so-called “custom-made” manner.

Next, a second embodiment of the present invention will be described with reference to FIG.
A microneedle 110 according to the second embodiment of FIG. 9 has a conical tip 102 and a truncated cone-shaped base 1. The microneedle 10 according to the first embodiment of FIG. 1 has a step S1 formed at the boundary between the end 1 side end of the tip 2 and the end 1 end of the base 1, whereas The microneedle 110 according to the second embodiment has a shape in which a base 1 side end portion (a lower end portion in FIG. 9) of the distal end portion 102 protrudes toward the base 1 side.
That is, a taper is formed at one end on the base side of the tip portion 102 of the microneedle 110 of the second embodiment so as to incline from the radially outer side to the inner side in the tip direction. Is shaped like an arrowhead.

In FIG. 9, a portion where the taper is formed at one end portion on the base side of the distal end portion 102 is indicated by reference numeral S <b> 2. In other words, in the second embodiment of FIG. 9, the boundary portion between the arrowhead-shaped end portion (lower end portion in FIG. 9) and the distal end side end portion (upper end portion in FIG. 9) of the base 1 is The step part shown by code | symbol S2 is comprised.
The tip portion 102 of the microneedle 110 of the second embodiment and the tip angle and height of the base 1 are determined in the same manner as the microneedle 10 of the first embodiment of FIG.
The shape of the tip portion 102 of the microneedle 110 according to the second embodiment may be a pyramid shape (triangular pyramid shape, quadrangular pyramid shape, polygonal pyramid shape of pentagon or more) as in the first embodiment. Further, the shape of the base 1 may be not only a conical shape but also a truncated pyramid shape (triangular frustum shape, quadrangular frustum shape, pentagonal pyramid shape or more) as in the first embodiment.

According to the microneedle 110 of the second embodiment in FIG. 9, even if an attempt is made to pull out the microneedle 110 after puncturing the skin, the base 1 side end of the tip 102 (arrowhead end: in FIG. 9) The lower end of the arrowhead shape is caught by the skin tissue, and it becomes more difficult to pull out from the skin (compared to the first embodiment).
The force for pulling out the microneedle 110 is concentrated in a region near the end portion on the base 1 side of the distal end portion 102 to cause stress concentration, and the microneedle 110 is torn near the boundary portion between the distal end portion 102 and the base 1.
When the microneedle 110 is torn near the boundary between the distal end portion 102 and the base 1, the portion on the distal end side (mainly the distal end portion 102) is in the dermis T (partly) as shown in FIG. In the stratum corneum Uh). Therefore, the medicinal effect of the medicine etc. constituting the microneedle 110 is exhibited over a long period of time.

Other configurations and operational effects in the second embodiment are the same as those in the first embodiment shown in FIGS.

It should be noted that the illustrated embodiment is merely an example, and is not a description to limit the technical scope of the present invention.
For example, although not specified in the illustrated embodiment, the “medicine etc.” which is the material of the microneedle of the present invention is a substance that contributes to the skin activity easily and reliably on the skin surface, such as drugs, cosmetics, and other skin activities. Yes, hyaluronic acid (for example, low molecular weight hyaluronic acid), hair restorer, supernatant of culture medium in which stem cells are cultured, and other materials that can give activity to skin, insulin, anticancer agent, hair restorer, hearing loss treatment Drugs for allergies (eg "hay fever"), drugs for the treatment of empyema, drugs for Alzheimer's disease or other dementia, drugs for brain diseases, drugs for the treatment of oral inflammation, periodontal diseases Drugs for alveolar bone regeneration, drugs for oral immunization factories, drugs for sunburn prevention and inflammation caused by sunburn, drugs for the treatment of psoriasis, drugs for the treatment of atopic dermatitis, acne (bedsores) Medicines for treating various skin diseases, drugs for regenerating skin for removing pregnancy lines, drugs for regenerating skin after wounds and other surgical operations, drugs for treating diseases caused by ringworm, Various other drugs (for example, Chinese medicine) such as drugs for increasing puncture and preventing ED are widely included.

In addition, in the illustrated embodiment, the case where the present invention is mainly applied to humans is described. However, animals that have many skin diseases and require microneedle treatment (dogs, cats, cows and other livestock, camels and other animals) The present invention can also be applied to animals. In such a case, the above-mentioned “medicine”, which is a material for producing microneedles, is used for domestic animals such as dogs, cats, cows and horses, and other animals such as camels (animals that have many skin diseases and need to be treated with microneedles. ) Use drugs that apply.

DESCRIPTION OF SYMBOLS 1 ... Base 2, 102 ... Front-end | tip part 10, 110 ... Microneedle 20 ... Type | mold U ... Skin Uh ... Horny layer S1, S2 ... Step part T ... Dermis

Claims (3)

It has a conical or pyramidal tip with a sharp tip and a truncated cone or truncated pyramid base, and a step is formed at the boundary between the base end of the tip and the tip end of the base. A microneedle characterized by having 2. The micro of claim 1, wherein a taper that is inclined in the distal direction from the radially outer side to the inner side is formed at an end of the distal end on the base side, and a cross-sectional shape of the distal end is formed in an arrowhead shape. needle. A manufacturing process for manufacturing a conical or pyramidal microneedle in advance;
A material filling step of filling a mold having a conical or pyramidal recess with a liquid material for producing microneedles;
A partial removal step of removing a part of the filled liquid material;
Inserting the tip of a microneedle manufactured in advance into the material remaining in the recess of the mold, and holding the tip in that state; and
A method for producing a microneedle comprising a step of taking out the microneedle when the material remaining in the recess of the mold is solidified.

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