Cap member, liquid agent supply device, and ion introduction system

Abstract

Provided is a cap member in which microneedles having through holes are appropriately arranged, in consideration of constraints on the arrangement of the microneedles having the through holes.　A plurality of microneedles 225 having through holes formed therein for ejecting a liquid agent to the outside are arranged over a circumference CIR1 on an ejection-side end surface 220AS. The radius r1 of the circumference CIR1 satisfies the following expression:　R-(L / 2) ≤ r1 ≤ R-(D / 2), where D is defined as a distance to be ensured as the distance between the center positions of the microneedles on the ejection-side end surface, the distance being determined in accordance with the constraints during production of the microneedles 225 and the strength of the cap member against pressing force; R is defined as the inner radius of the bottomed cylindrical cap member; and L is defined as the arc length on the circumference CIR1 between the center positions of two adjacent microneedles 225 when the number of the microneedles 225 arranged at equal intervals on the circumference CIR1 is maximized while maintaining the distance between the center positions on the injection side end surface at or greater than the distance D.

Description

Cap member, liquid drug supply device and iontophoresis system

[0001] The present invention relates to a cap member, a liquid drug delivery device, and an iontophoresis system.

[0002] Transdermal administration of drugs and the like has been widely practiced in the past. As a technology for transdermal administration of drugs and the like, a technology has been proposed in which fine needles called "microneedles" are used to eject a fixed amount of liquid through a microneedle having a through-hole formed therein in conjunction with the operation of a switch mechanism such as a knock-type switch (see Patent Document 1; hereinafter referred to as the "conventional example"). According to this conventional example technology, a liquid agent can be delivered to a desired position on the epidermis of a target (e.g., the surface or stratum corneum of human skin; the same applies hereinafter in this specification) with a simple operation.

[0003] JP 2023-094304 A

[0004] In the conventional technology, a shaft portion having a storage space for storing a liquid agent is connected to a liquid agent ejection portion (microneedle portion in the conventional technology) having a microneedle with a through-hole via a connecting portion, where the liquid agent ejection portion is configured to be threadably coupled to the connecting portion.

[0005] In the conventional technology, the liquid agent contained in the storage space is pushed toward the liquid agent ejection unit by, for example, manually knocking, thereby ejecting the liquid agent to the outside through the through-hole of the microneedle. Here, the diameter of the through-hole is significantly smaller than the diameter of the flow path through which the liquid agent reaches the through-hole.

[0006] For this reason, depending on the number of microneedles with through holes formed therein (eight examples have been disclosed in conventional examples), a large knocking force (pressing force) was required to eject (eject) the liquid agent from the through holes of the microneedles. In order to reduce this required knocking force, it is conceivable to increase the number of microneedles with through holes formed therein, but to form microneedles with through holes formed therein, it is necessary to make the distance between the microneedles and the distance between the microneedles and the inner wall of the liquid agent ejection portion equal to or greater than the respective required distances, which restricts the placement positions of the microneedles.

[0007] However, the conventional examples do not disclose any technology for arranging microneedles while taking into consideration the constraints on the placement position. Therefore, there is a demand for a technology for arranging microneedles while taking into consideration the constraints on the placement position.

[0008] Furthermore, as described above, conventional techniques require a large pressing force to be applied to the liquid when ejecting the liquid. However, conventional techniques use a screw-type connection between the liquid ejection unit and the connecting unit. Therefore, the large pressing force can cause the liquid to leak from the screw-type connection unit when ejecting the liquid. In order to reduce the amount of unintended liquid leakage, it is desirable to reduce the pressing force required to eject (eject) the liquid from the microneedle compared to conventional techniques.

[0009] Furthermore, in the conventional technology, when a liquid preparation is supplied to the epidermis of a living organism such as a human being for transdermal absorption of an active ingredient, the diffusion of the active ingredient within the epidermis is left to the mechanism of the target itself, and therefore there is room for technical improvement from the viewpoint of efficient diffusion of the active ingredient within the epidermis of the target.

[0010] The present invention has been made in consideration of the above circumstances, and aims to provide a cap member in which microneedles having through holes are appropriately arranged, taking into consideration restrictions on the arrangement position of the microneedles having through holes, and a liquid drug delivery device including the cap member. Another aim of the present invention is to provide an iontophoresis system that can promote diffusion of an active ingredient contained in a delivered liquid drug inside the epidermis of a delivery target.

[0011] From a first viewpoint, the present invention provides a cap member provided in a liquid agent supplying device that injects a liquid agent containing an active ingredient to the outside and supplies it to the epidermis of a target, the cap member being provided at an end of the liquid agent supplying device in an injection direction of the liquid agent, the cap member having a bottomed cylindrical shape that is open on a side opposite to the injection direction, the injection side end face of the cap member having through holes for injecting the liquid agent to the outside and having a plurality of microneedles arranged thereon that protrude in the injection direction, the plurality of microneedles including a first number of first microneedles arranged on a first circumference centered on a center point of the injection side end face, the amounts of the liquid agent injected from each of the first number of first microneedles in response to a pressing force in the injection direction being equal to each other, and a radius r1 of the first circumference satisfies the following formula (1): r1≦R−(D1 / 2) ... (1) (Here, a first distance that should be secured as the distance between the central positions of the first number of first microneedles adjacent to each other on the emission side end face, which is determined according to the constraints when manufacturing the first number of first microneedles and the strength of the cap member against the pressing force, is defined as distance D1, and the inner radius of the cap member is defined as R.) The radius r1 further satisfies the following formula (2): R - (L / 2) ≦ r1 ... (2) (Here, when the distance between the central positions of the first number of first microneedles adjacent to each other on the emission side end face is equal to or greater than the first distance D1 and the number of first microneedles arranged on the first circumference is maximized, the arc length on the first circumference between two adjacent first number of first microneedles is defined as L.) This is a cap member characterized in that all of the distances between the central positions of the first number of first microneedles on the emission side end face are equal to or greater than the first distance D1.

[0012] In this cap member, a first number of first microneedles are arranged on a circumference (radius r1) centered on the center point of the emission-side end face. Here, according to the findings obtained by the present inventor as a result of research and development, when the first distance to be secured as the distance between the centers of adjacent first microneedles on the emission-side end face, which is determined according to the constraints when forming the first microneedles and the strength of the cap member against pressing force, is distance D1, and the inner radius of the cap member is R, depending on conditions such as the material of the cap member and the thickness of each wall, by appropriately selecting radius r1 from within the range that satisfies the conditions of equations (1) and (2), it is possible to increase the number of first microneedles that can be arranged on the first circumference.

[0013] Furthermore, the length (L / 2) can be arranged at equal intervals at a distance D1 on the first circumference of the first microneedle, and if this equal interval arrangement is made and the number of equal interval arrangements is large, it can be said to be substantially the same as the distance D1.

[0014] Therefore, the cap member of the present invention allows the first microneedle having a through hole to be appropriately positioned while taking into consideration restrictions on the placement position of the microneedle having a through hole, and also allows the amount of the liquid agent to be uniform in a region corresponding to the vicinity of the first circumference of the target to which the liquid agent is to be supplied.

[0015] In the cap member of the present invention, the first number of first microneedles may have the same shape as each other, and the first number may be the maximum number of first microneedles that can be arranged at equal intervals on the first circumference. In this case, the amount of liquid agent ejected from the first microneedles can be easily made equal to each other, and the ejection area of ​​the liquid agent when the first microneedles are arranged at equal intervals on the first circumference can be maximized. This can contribute to reducing the pressing force on the liquid agent to eject the liquid agent.

[0016] Furthermore, in the cap member of the present invention, a cylindrical base having a maximum height equal to the height of protrusion of the first microneedle from the injection-side end face may be formed inside the first circumference of the injection-side end face. In this case, the base functions as a "non-slip" that suppresses displacement (so-called "lateral displacement") of the first microneedle on the epidermis of the target to be supplied with the first microneedle. Therefore, the supply position of the liquid agent by the first microneedle on the epidermis of the target to be supplied with the liquid agent can be stabilized.

[0017] Furthermore, in the cap member of the present invention, an annular platform having a maximum height equal to the height of protrusion of the first microneedle from the injection-side end face may be formed on the outside of the first circumference of the injection-side end face. In this case, the annular platform functions as a "non-slip" that prevents the first microneedle from shifting (so-called "lateral shifting") on the epidermis of the target. This allows for stabilization of the delivery position of the first microneedle on the epidermis of the target when delivering a liquid agent.

[0018] The cap member of the present invention may further include at least one solid microneedle extending along a straight line extending from the center point of the ejection-side end face toward each of the first number of microneedles to a height higher than the height at which the first microneedle protrudes in the first direction from the region where the ejection-side end face is formed. In this case, the solid microneedle functions as a "non-slip" that prevents the first microneedle from shifting (so-called "lateral shift") on the epidermis of the target to be supplied with the first microneedle. This allows for stabilization of the delivery position of the liquid agent by the first microneedle on the epidermis of the target to be supplied with the liquid agent, and, if the target is a human, allows for the user to experience the sensation of use (so-called tingling sensation) of a liquid agent delivery device including the cap member.

[0019] Here, the emission-side end face may further include a base formed in at least a portion of an area other than the area where the first number of first microneedles are formed, the base having a protruding height lower than the protruding height of the first microneedles from the emission-side end face in the first direction, and the at least one solid microneedle may be formed on the base. In this case, the protruding height of the first microneedle from the emission-side end face may be the same as the protruding height of the solid microneedle from the upper surface of the base.

[0020] Furthermore, in the cap member of the present invention, the plurality of microneedles include a second number of second microneedles that are arranged in an inner region of the first circumference and have a protruding height equivalent to that of the first microneedles, the amounts of the liquid agent ejected from each of the second microneedles in response to the pressing force in the ejection direction are equivalent to each other, and the center positions of the second microneedles on the ejection side end face are all separated by a distance equal to or greater than a second distance D2 (here, the second distance that should be ensured between adjacent second microneedles, which is determined according to constraints when forming the second microneedles and the strength of the cap member against the pressing force, is defined as distance D2). The distance D between the center position of the second microneedle on the ejection side end face and the center position of the first microneedle on the ejection side end face is equal to or greater than a second distance D2. 12 It can be said that all of these satisfy the following formula (3): D 12 ≧(D1 / 2)+(D2 / 2)...(3)

[0021] In this case, when the arrangement of the second microneedles as described above is possible, in addition to the first number of first microneedles, a second number of second microneedles are arranged on the emission side end surface. Then, the distance between the first microneedles and the second microneedles is defined as distance D 12 The second number of second microneedles are arranged while satisfying the above formula (3) and ensuring that the distance between the second microneedles is equal to or greater than the distance D2.

[0022] Therefore, it is possible to increase the number of microneedles having through holes while taking into consideration the restrictions on the arrangement of the microneedles having through holes, and to appropriately arrange the microneedles.

[0023] Here, the second number of second microneedles may be arranged on a second circumference in an area inside the first circumference. In this case, the center of the second circumference and the center of the first circumference may coincide with each other, and the radius r2 of the second circumference may be selected to satisfy the following formula (4): r1 - [(D1 / 2) + (D2 / 2)] ≧ r2 ≧ (D2 / 2) ... (4)

[0024] In this way, by arranging the second number of second microneedles on the second circumference of radius r2, the second microneedles can be arranged appropriately.

[0025] When a second number of second microneedles are arranged on the second circumference, the second number of second microneedles may have the same shape, and the second number may be the maximum number of second microneedles that can be arranged at equal intervals on the second circumference. In this case, the amount of liquid ejected from each of the second microneedles can be easily made equal, and the ejection area of ​​the liquid when the second microneedles are arranged at equal intervals on the second circumference can be maximized. This can contribute to reducing the pressing force on the liquid to eject the liquid.

[0026] Furthermore, when both first and second microneedles are disposed, the diameter of the second microneedles can be determined based on the ratio between the first inflow velocity V1 of the liquid into each of the first microneedles and the second inflow velocity V2 of the liquid into each of the second microneedles so that the first individual ejection amount of the liquid from each of the first microneedles and the second individual ejection amount of the liquid from each of the second microneedles are equal. In this case, it is possible to achieve uniform distribution of the liquid amount in the target to which the liquid is supplied.

[0027] Furthermore, the ratio between the diameter of the through hole of each of the first number of first microneedles and the diameter of the through hole of each of the second number of second microneedles can be determined based on the ratio between the first inflow velocity V1 of the liquid into each of the first microneedles and the second inflow velocity V2 of the liquid into each of the second microneedles, and the ratio between the first number and the second number, so that the first total amount of the liquid ejected from all the first microneedles is equal to the second total amount of the liquid ejected from all the second microneedles.

[0028] In this case, the amount of liquid medicine supplied to the region around the first circumference of the supply target can be made equal to the amount of liquid medicine supplied to the region around the second circumference.

[0029] The first inflow velocity V1 and the second inflow velocity V2 may be evaluated by applying the Hagen-Poiseuille law based on the shape of the cylindrical flow path through which the liquid material is pressed toward the injection-side end face. In this case, the first inflow velocity V1 and the second inflow velocity V2 can be evaluated rationally.

[0030] From a second viewpoint, the present invention provides a liquid agent supply device comprising the cap member of the present invention, and further comprising: a shaft portion having a liquid agent storage space for storing the liquid agent formed along the injection direction; and a connecting portion disposed at a first end of the shaft portion in the injection direction, connecting the shaft portion and the cap member.

[0031] In this liquid drug delivery device, when a pressing force is applied to the liquid drug contained in the liquid drug storage space of the stem, the liquid drug is ejected from the through-hole of the microneedle formed in the cap member of the present invention via the connecting portion. Therefore, it is possible to reduce the pressing force on the liquid drug for ejecting the liquid drug while equalizing the amount of the liquid drug in the circumferential region of the target.

[0032] From a third viewpoint, the present invention provides a liquid agent supply device of the present invention; and a diffusion facilitation device; the diffusion facilitation device includes a first cylindrical member, a second cylindrical member, a first electrode, a second electrode, and a battery unit; the first cylindrical member has a first storage space formed therein, the first storage space extending along the ejection direction and storing a first predetermined portion of the liquid agent supply device on the opposite side of the ejection direction; and the second cylindrical member has a first storage space disposed in the ejection direction of the first cylindrical member, through which the cap member can be penetrated along the ejection direction but which the shaft portion cannot be penetrated along the ejection direction. The iontophoresis system is characterized in that a through hole is formed and a second storage space is formed to store a second predetermined portion of the liquid drug supply device on the injection direction side; the first electrode is used to promote diffusion of the active ingredient; the second electrode forms a current path between the first electrode and the second electrode through the inside of the epidermis of the supply target when the active ingredient is diffusing; the battery unit generates a predetermined potential difference between the first electrode and the second electrode, and the storage space of the liquid drug supply device is formed from the first storage space and the second storage space.

[0033] In this iontophoresis system, when a liquid formulation is supplied or being supplied to a target via a cap member of a liquid formulation supply device housed in an internal storage space, a current path is formed between the first electrode and the second electrode through the interior of the target's epidermis, and the iontophoresis effect promotes diffusion of an active ingredient contained in the liquid formulation within the target's epidermis (e.g., human epithelium; the same applies below). Thus, the iontophoresis system of the present invention can, with a compact configuration, supply a liquid formulation containing an active ingredient to a target and promote diffusion of the active ingredient contained in the supplied liquid formulation within the target's epidermis.

[0034] From a fourth viewpoint, the present invention provides a method for designing microneedle arrangement positions in a bottomed cylindrical cap member provided in a liquid agent supplying device that injects a liquid agent containing an active ingredient to the outside and supplies it to the epidermis of a target, the cap member being disposed at an end in the injection direction of the liquid agent supplying device, the cap member having a through-hole formed therein for injecting the liquid agent, and the cap member having an injection-side end face on which a plurality of microneedles of identical shapes are arranged, the method comprising: a radius calculation step of calculating a radius r of a circumference of a circle having a center at a center point of the injection-side end face on which central positions of the plurality of microneedles are arranged, the radius r satisfying the following formula (5): R-(L / 2)≦r≦R-(D / 2) ... (5) (Here, the distance that should be secured as the distance between the center positions of the microneedles on the injection side end face is defined as distance D, which is determined according to the constraints imposed when manufacturing the microneedles and the strength of the cap member against the pressing force; the inner radius of the cap member is defined as R; the distance between the center positions of the microneedles on the injection side end face is defined as distance D or more, and when the number of microneedles arranged when equally spaced on the circumference is maximized, the arc length on the circumference between the center positions of two adjacent microneedles is defined as L.) A method for designing microneedle arrangement positions, comprising: a placement position determination step of determining positions at which the microneedles are to be arranged at equal intervals on the circumference while separating any two of the microneedles by the distance D or more.

[0035] In this method for designing microneedle placement positions, in the radius calculation step, the radius r of the circumference centered on the center point of the emission-side end face is calculated so as to satisfy the condition of the above formula (5). Therefore, although it depends on conditions such as the material of the cap member and the thickness of the surface, by appropriately selecting the radius r within a range that satisfies the condition of formula (5), it is possible to increase the number of microneedles that can be placed on the circumference. Next, in the placement determination step, the positions at which the microneedles are placed are determined at equal intervals on the circumference while ensuring a separation distance of at least the distance D. Therefore, it is possible to appropriately determine the positions at which the microneedles with through holes are formed, taking into account the constraints on the placement of the microneedles with through holes.

[0036] According to the cap member of the present invention, the microneedles having through holes can be appropriately positioned to reduce the pressing force for ejecting (spraying) the liquid agent, taking into consideration the restrictions on the placement of the microneedles having through holes. Furthermore, according to the liquid agent supply device of the present invention, it is possible to reduce the pressing force on the liquid agent for ejecting the liquid agent, while equalizing the amount of the liquid agent in the peripheral region around the circumference where the microneedles are placed on the supply target.

[0037] The diffusion promoting device of the present invention has a compact configuration and can promote the diffusion of an active ingredient contained in a liquid preparation supplied to a target within the target's epidermis. Furthermore, the iontophoresis system of the present invention has a compact configuration and can supply a liquid preparation containing an active ingredient to a target, while promoting the diffusion of the active ingredient contained in the supplied liquid within the target's epidermis.

[0038] Furthermore, according to the method for designing the microneedle formation position of the present invention, the position for placing the microneedle having a through-hole can be appropriately determined while taking into consideration the constraints on the placement of the microneedle having a through-hole.

[0039] 1 is a perspective view illustrating the configuration of an iontophoresis system according to a first embodiment of the present invention. FIG. 2 is a perspective view illustrating the configuration of the liquid agent supply device of FIG. 1. FIG. 3 is a cross-sectional view (X-Z cross-sectional view) illustrating the internal configuration of the +Z direction side (tip side) of the liquid agent supply device of FIG. 2. FIG. 4 is a view (part 1) illustrating the configuration of the cap member of FIG. 2. FIG. 5 is a diagram illustrating an example of a contact state between the cap member of FIG. 2 and a liquid agent supply target. FIG. 6 is a view (part 2) illustrating the configuration of the cap member of FIG. 2. FIG. 7 is a view illustrating a change in the positional relationship between elements of the liquid agent supply device in response to a knocking operation (depressing operation (pressing operation)) on the liquid agent supply device of FIG. 2. FIG. 8 is a cross-sectional view (part 1: X-Z cross-sectional view) illustrating the internal configuration of the diffusion facilitation device of FIG. 1. FIG. 9 is a cross-sectional view (part 2: Y-Z cross-sectional view) illustrating the internal configuration of the diffusion facilitation device of FIG. 1. FIG. 10 is a view illustrating a change in the positional relationship between the diffusion facilitation device and the liquid agent supply device in response to a pressing operation on the diffusion facilitation device of FIG. 1. FIG. 11 is a view (part 1) illustrating the configuration of a cap member according to a second embodiment of the present invention. FIG. 12 is a view (part 2) illustrating the configuration of a cap member according to a second embodiment of the present invention. 14 is a diagram illustrating a modified example of the shape of the microneedle. FIG. 15 is a diagram illustrating a modified example (part 1) of the cap member. FIG. 16 is a cross-sectional view (YZ cross-sectional view) illustrating the internal configuration of the cap member of FIG. 14. FIG. 17 is a diagram illustrating an example of a contact state between the cap member of FIG. 14 and a target for supplying a liquid agent. FIG. 18 is a diagram illustrating a modified example (part 2) of the cap member. FIG. 19 is a diagram illustrating a modified example (part 3) of the cap member.

[0040] Hereinafter, an embodiment of the present invention will be described with reference to Figures 1 to 12. In the following description and drawings, the same elements are designated by the same reference numerals, and duplicate explanations will be omitted. In the drawings, the dimensions, aspect ratios, etc. of each element are appropriately changed for ease of viewing.

[0041] First Embodiment First, an iontophoresis system 300A, a liquid drug supply device 200A, and a cap member 220A according to a first embodiment of the present invention will be described with reference to FIGS.

[0042] <Configuration> Fig. 1 is a perspective view showing a schematic configuration of an iontophoresis system 300A. As shown in Fig. 1, the iontophoresis system 300A includes a diffusion facilitation device 100 and a liquid preparation supply device 200A. The iontophoresis system 300A of this embodiment is a system that performs iontophoresis of an active ingredient contained in a liquid preparation to a human being.

[0043] 1 , the diffusion facilitation device 100 includes a first cylindrical member 110, a second cylindrical member 120 positioned closer to the +Z direction (first direction, third direction) than the first cylindrical member 110, and a pressing member 130 disposed at one of both end portions of the first cylindrical member 110 that is positioned closer to the −Z direction (second direction, fourth direction). A liquid agent supply device 200A can be accommodated in the internal space of the diffusion facilitation device 100 formed by the first cylindrical member 110 and the second cylindrical member 120.

[0044] Here, the second cylindrical member 120 is detachable from the first cylindrical member 110. To make it detachable in this manner, for example, a matable female thread and a male thread are formed on a part of the inner surface of one of both end portions of the first cylindrical member 110 that is closer to the +Z direction (ejection direction), and on the outer surface of one of both end portions of the second cylindrical member 120 that is closer to the −Z direction.

[0045] The diffusion promotion device 100 is sized so that it can be easily held by a person's palm and at least one finger (e.g., four fingers excluding the thumb), or by multiple fingers (e.g., the thumb and at least one finger other than the finger that presses against the pressing member 130).

[0046] As shown in Fig. 1, a first electrode 1151 is formed on the side of both side surfaces of the first cylindrical member 110 that is closer to the -X direction. Furthermore, although not shown in Fig. 1, a first electrode 1152 is formed on the side of both side surfaces of the first cylindrical member 110 that is closer to the +X direction. When promoting the diffusion of an active ingredient in a liquid formulation (described below) inside the epidermis, at least a part of the area where the diffusion facilitation device 100 is gripped is brought into contact with at least one of the first electrode 1151 and the first electrode 1152.

[0047] 1, a first through hole OP1 is formed in the end closer to the +Z direction of both end portions of the second cylindrical member 120. A second electrode 125 is formed around the first through hole OP1 in the end closer to the +Z direction of both end portions of the second cylindrical member 120.

[0048] Here, when promoting diffusion of the active ingredient of the liquid formulation under the epidermis, the epidermis of the end portions of the second electrode 125 that is closer to the +Z direction is pressed against the epidermis at the site where the liquid formulation is injected. Therefore, when promoting this diffusion, a current path for a weak current is formed between the second electrode 125 and at least one of the first electrode 115 and the first electrode 115, passing through the inside of the epidermis of the target to be supplied.

[0049] The first cylindrical member 110 and the second cylindrical member 120 are made of an insulating material, such as reinforced plastic, which is easy to mold.

[0050] The internal structure of the diffusion promoting device 100 will be described in detail later.

[0051] <Configuration of liquid agent supply device 200A> In this embodiment, the liquid agent supply device 200A is configured in the same manner as the liquid applicator disclosed in the conventional example, except that it is provided with a cap member 220A instead of a microneedle portion (see FIG. 2).

[0052] 2, the solution supplying device 200A includes a shaft portion 210, a connecting portion 250, and a cap member 220A. The solution supplying device 200A also includes a knock portion 230.

[0053] The shaft 210 is a hollow cylindrical member made of reinforced plastic, at least a portion of which is optically transparent. As shown in FIG. 2 , the shaft 210 has a large diameter portion 211 and a small diameter portion 212 located closer to the +Z direction than the large diameter portion 211.

[0054] Of the two ends of the shaft portion 210, a connecting portion 250 is disposed at the end located closer to the +Z direction. This connecting portion 250 is also a hollow cylindrical member made of reinforced plastic, and at least a portion thereof is optically transparent. The internal space of this connecting portion 250 communicates with the internal space of the shaft portion 210 when the liquid agent can be supplied (see FIG. 3 ). As will be described later, a liquid agent containing space LS is formed by the portion of the internal space of the shaft portion 210 closer to the +Z direction and the internal space of the connecting portion 250.

[0055] A cap member 220A that can be attached to and detached from the connecting part 250 is disposed at the end of the connecting part 250 in the +Z direction. This cap member 220A is also a hollow, bottomed, cylindrical member made of reinforced plastic, and at least a portion of it is optically transparent. Here, the connecting part 250 and the cap member 220A are detachably connected by threading a female thread formed on the outer surface of the end of the connecting part 250 in the +Z direction into a male thread formed on the inner surface of the cap member 220A.

[0056] The cap member 220A has a cylindrical shape with a bottom, with an emission side end face 220AS located at the end in the +Z direction. A plurality of truncated cone-shaped microneedles 225 protruding in the +Z direction are arranged on the emission side end face 220AS. These microneedles 225 have through holes that connect the internal space of the cap member 220A to the outside. The liquid agent is discharged to the outside through the through holes.

[0057] The configuration of the cap member 220A will be described in detail later.

[0058] Knocking portion 230 is disposed at the −Z direction end of shaft portion 210. When the −Z direction end face of knocking portion 230 is pressed in the +Z direction, knocking portion 230 is pressed in the +Z direction, and knocking portion 230 moves in the +Z direction. In response to this movement of knocking portion 230 in the +Z direction, the liquid agent contained in liquid agent containing space LS is ejected via the through-hole formed in microneedle 225 described above.

[0059] When the pressing operation ends after pressing the end face of the knock portion 230 in the -Z direction in the +Z direction, the knock portion 230 returns to the Z position it was in before the pressing started.

[0060] The internal space of the shaft portion 210 accommodates a liquid agent extruding portion 240 that is used to eject the liquid agent from the through-hole of the microneedle 225. The liquid agent extruding portion 240 includes a constant amount moving portion 241 disposed on the −Z direction side of the shaft portion 210, a shaft 242, and a piston 243.

[0061] The quantitative movement unit 241 is adapted to receive a pressing force resulting from a knocking operation on the knock unit 230. When receiving such a pressing force, the quantitative movement unit 241 advances the shaft 242 by a certain amount in the +Z direction, similar to a known knock-type mechanical pencil, as disclosed in the conventional example.

[0062] It should be noted that the shaft 242 that has advanced a certain amount in response to the pressing operation on the knock portion 230 remains at the position where it has advanced a certain amount even after the pressing operation is terminated.

[0063] The piston 243 is disposed at the end of the shaft 242 on the +Z direction side. The piston 243 includes a cylindrical main body 246 whose side surface is in close contact with the inner wall of the shaft 210, and a protrusion 247 disposed on the +Z direction side of the main body 246. The protrusion 247 has a smaller diameter than the main body 246 and is shaped like a truncated cone whose outer diameter gradually decreases along the +Z direction.

[0064] At least the portion of the main body 246 that comes into contact with the inner wall of the shaft 210 is made of an elastic material such as synthetic rubber.

[0065] 3 is a schematic XZ cross-sectional view of the +Z direction side of solution supply device 200A. As shown in Fig. 3, in the internal space of shaft portion 210, piston 243 is movable within the internal space of large diameter portion 211. However, once the +Z direction end of main body portion 246 reaches the +Z direction end of the internal space of large diameter portion 211, piston 243 is no longer able to move further along the +Z direction. As described above, piston 243 moves along the +Z direction in response to the pressure of knock portion 230 in the +Z direction.

[0066] As clearly shown in FIG. 3 , a liquid agent containing space LS is formed by the portion of the internal space of the shaft portion 210 on the +Z direction side of the piston 243 and the internal space of the connecting portion 250 .

[0067] <Configuration of Cap Member 220A> Fig. 4 shows the configuration of the cap member 220A. Note that quantitative descriptions of dimensions, arrangement positions, etc. in the following description include manufacturing errors.

[0068] 4A to 4C , a plurality of microneedles 225 (ten in the first embodiment) protruding in the +Z direction are formed on the emission-side end surface 220AS of the cap member 220A. A cylindrical base 221 protruding in the Z direction at a height equivalent to that of the microneedles 225 is formed in the center of the emission-side end surface 220AS. Furthermore, an annular base 222 protruding in the Z direction at a height equivalent to that of the microneedles 225 is formed on the outer periphery of the emission-side end surface 220AS. In this embodiment, the protruding heights of the cylindrical base 221 and the annular base 222 are slightly higher than the protruding height of the microneedles 225.

[0069] 4(A), all of the microneedles 225 are arranged at equal intervals on an imaginary circumference CIR1, which is centered on the center point CP and indicates the reference position of the microneedles 225. Also, as shown in FIG. 4(B), the inner diameter of the cap member 220A in the XY plane is "2R", and the inner diameter of the connecting portion 250 is also "2R". In other words, the radius R of the flow path to the microneedle 225 of the liquid agent supplied to the microneedle 225 by pressing the knock portion 230 is FL is marked with "R".

[0070] As shown in Figure 4 (C), the diameter of the through hole of the microneedle 225 is "d11" and the protruding height of the microneedle 225 is "H", which is equivalent to that of the first microneedle in the conventional example.

[0071] 4(C), the microneedle 225 has an emission-side end surface 220AS as an end surface closer to the +Z direction. The flat plate-like portion with a thickness of "T" has a truncated cone-shaped so-called back hole formed in the -Z direction of the formation position in the XY plane of each microneedle 225. The diameter of the opening of this back hole closer to the +Z direction is "d12 (> d11)" and the diameter of the opening closer to the -Z direction is "d13 (> d12)". The through hole with the diameter "d11" described above extends from the tip of the microneedle 225 closer to the +Z direction to the back hole.

[0072] When manufacturing the cap member 220A, a resin material (e.g., polypropylene) is first injected into the internal space of a mold to create a pre-through-hole formation member having the same external shape as the cap member with the through-hole filled in. Subsequently, a through-hole is formed by laser ablation, which is performed by irradiating a laser beam in the -Z direction to the tip of the portion that will become the microneedle 225, closer to the +Z direction. In this way, the cap member 220A is manufactured.

[0073] 5 shows a state in which the cap member 220A is pressed against a supply target OBJ having elasticity, such as human skin, etc. As shown in Fig. 5, the cylindrical base 221 and the annular base 222 are pressed against each other, causing the tip of the microneedle 225 to come into contact with a portion of the target OBJ that rises in the -Z direction.

[0074] <Arrangement of Microneedles 225> Next, the arrangement of the microneedles 225 will be described with reference to Fig. 6. The inner diameter (2R) of the cap member 220A in the XY plane is determined from the viewpoint of suitability for a user of operations when the solution supply device 200A is used. For example, the inner diameter 2R is set to a value within a predetermined range according to constraints from the viewpoint of comfortable gripping of the solution supply device 200A (and thus the iontophoresis system 300A) with the palm and / or fingers, and suitability for a knocking operation (pressing operation) of the knock portion 230 (and thus the pressing member 130) with fingers not used for gripping.

[0075] After determining the radius R as close to the maximum value within the predetermined range, the radius r1 of the circumference CIR1 centered at the center point CP described above is calculated as follows. First, a first distance (distance D1) that should be maintained as the distance between the centers of adjacent first microneedles 225 on the ejection-side end face 220AS is calculated, which is determined according to the constraints imposed when forming the first microneedles 225 and the strength of the cap member 220A against the pressing force when ejecting the liquid agent. Furthermore, the arc length L of two adjacent first microneedles 225 is calculated when the number of first microneedles 225 arranged on the circumference CIR1 is maximized while the distance between the centers of adjacent first microneedles 225 on the ejection-side end face 220AS is set to be equal to or greater than the distance D1.

[0076] Then, a radius r1 is calculated that satisfies the following formula (1): r1≦R−(D1 / 2) (1) and also satisfies the following formula (2): R−(L / 2)≦r1 (2)

[0077] Here, the condition of equation (2) is added in addition to the condition of equation (1) based on the knowledge gained by the inventors as a result of research and development that the distance to be secured between the center position of the emission side end surface 220AS of the first microneedle 225 and the cylindrical inner wall of the cap member 220A is sufficient, including a margin, if it is always set to a distance (L / 2) longer than the distance D1.

[0078] It should be noted that it is possible to arrange the elements at equal intervals of distance D1 on the circumference CIR1, and if such equal intervals are arranged and the number of equal intervals arranged is large, then distance D1 and distance L will be approximately the same.

[0079] Next, the number N1 of the microneedles 225 arranged on the circumference CIR1 is determined so as to satisfy the condition of the following formula (6): 2r1·sin(2π / N1)≧(D1)>2r1·sin(2π / (N1+1)) (6)

[0080] The arrangement position of the microneedles 225 at the central angle θ1 (=2π / N1), i.e., the distance G1 (=2r1·sin(2π / N1)) between the microneedles 225, is determined according to the arrangement number N1 determined in this manner.

[0081] 7 shows the movement of piston 243 in response to a pressing operation on knock portion 230. Before this pressing, piston 243 was in the Z direction position shown in Fig. 7(A). Note that Fig. 7(A) clearly shows the reference numerals of the components of solution supply device 200A, and Figs. 7(B) and 7(C) clearly show the reference numerals of the components that appear in the following description.

[0082] 7(A), when the knock portion 230 is pressed once, the shaft 242 moves a certain amount d1 in the +Z direction, as shown in FIG. 7(B). Then, the piston 243 pushed by the shaft 242 moves a certain amount d1 along the +Z direction. As a result, an amount of the liquid corresponding to the certain amount d1 in the liquid storage space LS is ejected to the outside through the through-hole formed in the microneedle 225.

[0083] When the pressure on knock portion 230 shown in Fig. 7(B) is released, the position of knock portion 230 in the Z direction returns to the same position as in Fig. 7(A), as shown in Fig. 7(C). Meanwhile, the position of piston 243 in the Z direction remains in the position shown in Fig. 7(B).

[0084] <Liquid Agent Storing in the Liquid Agent Storage Space LS> Here, the liquid agent stored in the liquid agent storage space LS will be described.

[0085] The liquid agent contained in the liquid agent storage space LS may be, for example, an aqueous solution containing, as the main component (active ingredient), a culture supernatant powder of stem cells selected from the group consisting of non-human mammalian dental pulp stem cells, bone marrow stem cells, and adipose stem cells. The liquid agent contained in the liquid agent storage space LS is not limited to these, and any aqueous solution containing an active ingredient whose physiological activity is suitable for the desired cosmetic purpose may be used. The stem cells may also be those into which a specific gene set has been introduced by a known method.

[0086] In this embodiment, the active ingredient in the liquid preparation is assumed to be negatively ionized.

[0087] <Internal Configuration of Diffusion Facilitation Device 100> Next, the internal configuration of the diffusion facilitation device 100 will be described.

[0088] 8 and 9 show the internal configuration of the diffusion promoting device 100. Here, Fig. 8 is an XZ cross-sectional view including the axis AX (see Fig. 1), and Fig. 9 is a YZ cross-sectional view including the axis AX.

[0089] 8 and 9, storage spaces CS1 to CS3 are formed inside the diffusion facilitation device 100. Here, the storage spaces CS1 and CS3 are storage spaces formed by the first cylindrical member 110, and the storage space CS2 is a storage space formed by the second cylindrical member 120.

[0090] The storage space CS1 and the storage space CS2 are continuous with each other, and the solution supply device 200A is stored in the storage space CS formed by the storage space CS1 and the storage space CS2. The storage space CS3 stores the battery unit 190. The storage space CS3 is substantially isolated from the storage space CS by the internal partition of the first cylindrical member 110.

[0091] Small holes (not shown) for electrical wiring are appropriately formed in the internal partition wall, the outer wall and internal partition wall of the first cylindrical member 110, and the outer wall of the second cylindrical member 120. Electrical wiring (not shown) inserted through some of these small holes directly or indirectly electrically connects the anode of the battery unit 190 to the first electrodes 115 and 115, and also directly or indirectly electrically connects the cathode of the battery unit 190 to the second electrode 125.

[0092] In this embodiment, the battery unit 190 is, for example, a rechargeable battery unit. Electrical wiring between the battery unit 190 and a connector (not shown) for receiving external power used for charging is also inserted through some of the small holes.

[0093] Of both end portions of the second cylindrical member 120, the end portion closer to the −Z direction is formed with a first through hole OP1 that allows the cap member 220A of the above-mentioned solution supply device 200A to penetrate to the outside in the Z direction but cannot penetrate the shaft portion 210. Furthermore, of both end portions of the first cylindrical member 110, the end portion closer to the −Z direction is formed with a second through hole OP2 that connects the storage space CS1 to the outside and allows the solution supply device 200A to penetrate along the Z direction.

[0094] The pressing member 130 has the same diameter as the second through hole OP2 of the first cylindrical member 110, and is insertable into and removable from the storage space CS via the second through hole OP2. When a portion of the pressing member 130 closer to the +Z direction is inserted into the storage space CS, the pressing member 130 engages with the inner wall of the first cylindrical member 110 in a manner that allows it to move along the Z direction within the storage space CS. Here, the pressing member 130 is configured to come into contact with the end face closer to the −Z direction of both end faces of the knock portion 230 of the stored solution supply device 200A.

[0095] The solution supply device 200A can be stored in the storage space CS by (a) inserting the solution supply device 200A into the storage space CS through the second through-hole OP2 in the +Z direction with the pressing member 130 removed, and then inserting the pressing member 130 into the storage space CS through the second through-hole OP2. Alternatively, (b) inserting the solution supply device 200A into the storage space CS1 in the −Z direction from the end of the storage space CS1 closer to the +Z direction with the first cylindrical member 110 and the second cylindrical member 120 separated, and then connecting the first cylindrical member 110 and the second cylindrical member 120, thereby storing the solution supply device 200A in the storage space CS. In the case of (b), the pressing member 130 may be inserted into the storage space CS at any timing.

[0096] An elastic member 123 is disposed in the storage space CS2. One end of the elastic member 123 is in contact with or connected to the inner wall surface of the end closer to the +Z direction of both ends of the second cylindrical member 120. The other end of the elastic member 123 is in contact with the outer wall surface of the end closer to the +Z direction of both ends of the large diameter portion 211 of the stored solution supply device 200A. This elastic member 123 biases the stored solution supply device 200A in the −Z direction.

[0097] The elastic member 123 is configured to shorten in the Z direction in response to pressure applied to the pressing member 130 in the +Z direction until the tip of the microneedle having the through hole formed therein protrudes outward through the first through-hole OP1, and then not shorten any further. A helical spring or the like can be used as the elastic member 123. The shortened length of the elastic member 123 in the Z direction in response to pressure applied to the pressing member 130 in the +Z direction when the solution supply device 200A is stored in the storage space CS is defined as d2.

[0098] 10 shows the change in the positional relationship between the diffusion facilitation device 100 and the pressing member 130 in response to a pressing operation on the pressing member 130. Before this pressing, the positional relationship shown in FIG. 10(A) was assumed. Note that FIG. 10(A) shows the reference numerals of the components that will appear in the description of FIG. 10 (excluding the portion referred to in FIG. 7). Meanwhile, FIGS. 10(B) and 10(C) show the reference numerals of the components that will appear in the following description.

[0099] When the pressing member 130 is pressed once in the state shown in Fig. 10(A), as shown in Fig. 10(B), the liquid agent supply device 200A first moves a length d2 in the +Z direction relative to the diffusion facilitation device 100. Subsequently, when a pressing force corresponding to the pressing operation is transmitted to the knock portion 230 of the liquid agent supply device 200A, the shaft 242 moves a fixed amount d1 along the +Z direction, as shown in Fig. 7(B) described above. Then, the piston 243 pressed by the shaft 242 moves a fixed amount d1 along the +Z direction. As a result, an amount of liquid corresponding to the fixed amount d1 in the liquid agent storage space LS is ejected to the outside through the through-hole formed in the microneedle 225.

[0100] If the pressing operation causes the epidermis of the area where diffusion facilitation device 100 is gripped to come into contact with first electrode 115 and / or 115, and second electrode 125 to come into contact with the epidermis of the target area where the liquid is to be administered, a current path is formed between first electrode 115 and / or 115 and second electrode 125 via the inside of the epidermis, and a weak current is generated via this current path. In response to the weak current thus generated, the diffusion of the active ingredient contained in the liquid within the epidermis is promoted by the so-called iontophoresis effect.

[0101] When the pressure on the pressing member 130 shown in Fig. 10(B) is released, as shown in Fig. 10(C), the knock portion 230 returns to the same Z position as in the case shown in Fig. 7(A) described above, and the position of the liquid agent supply device 200A relative to the diffusion facilitation device 100 returns to the position shown in Fig. 10(A) due to the action of the biasing force in the -Z direction of the elastic member 123 described above. Also, the Z direction position of the pressing member 130 returns to the position shown in Fig. 10(A).

[0102] As described above, in the cap member 220A of the first embodiment, the radius r １ The microneedles 225 are arranged at equal intervals G1 on the circumference of the cap member 220A. Therefore, the microneedles 225 having through holes can be appropriately arranged in consideration of the restrictions on the arrangement of the microneedles 225 having through holes. Furthermore, the amount of the liquid agent can be made uniform in the circumferential area of ​​the supply target to which the liquid agent is supplied.

[0103] In addition, in the cap member 220A, the number of arrangements N on the circumference CIR1 is set to satisfy the condition of the above-mentioned formula (6). １ is the maximum number that can be arranged. Therefore, the ejection area of ​​the liquid agent when they are arranged at equal intervals on the circumference CIR1 can be maximized, which can contribute to reducing the pressing force on the liquid agent when ejecting the liquid agent.

[0104] Furthermore, in the cap member 220A, a cylindrical base 221 is formed in the center of the ejection-side end face 220AS, with a maximum height approximately equal to the height of the microneedles 225 protruding from the ejection-side end face 220AS. Therefore, the cylindrical base 221 functions as a "non-slip" that prevents the microneedles 225 from shifting (so-called "lateral shifting") on the epidermis of the target to be supplied. This makes it possible to stabilize the supply position of the microneedles 225 on the epidermis of the target to be supplied when supplying a liquid agent.

[0105] Furthermore, in the cap member 220A, an annular base 222 is formed on the outer periphery of the ejection-side end face 220AS, with a maximum height approximately equal to the height of the microneedles 225 protruding from the ejection-side end face 220AS. In this case, the annular base 222 functions as a "non-slip" that prevents the microneedles 225 from shifting (so-called "lateral shifting") on the epidermis of the target to be supplied. This makes it possible to stabilize the supply position of the microneedles 225 on the epidermis of the target to be supplied when supplying a liquid agent.

[0106] Furthermore, solution supply device 200A is configured to include connecting section 250. Therefore, when a pressing force is applied to the solution contained in solution containing space LS of shaft section 210, the solution is ejected from through-holes of microneedles 225 formed in cap member 220A after passing through connecting section 250. Therefore, it is possible to reduce the pressing force on the solution for ejecting the solution, while equalizing the amount of the solution in a solution supply region corresponding to the vicinity of the circumference of the epidermis of the supply target.

[0107] Furthermore, in the iontophoresis system 300A, when a liquid is supplied or being supplied to a target from the cap member 220A of the liquid supply device 200A housed in the internal storage space CS, a current path is formed between the first electrode 115 and / or 115 and the second electrode 125 through the target's epidermis, promoting diffusion of the active ingredient contained in the liquid within the target's epidermis (e.g., the stratum corneum). That is, the iontophoresis effect promotes diffusion of the liquid within the target's epidermis. Therefore, the diffusion promoting device 100 can promote diffusion of the active ingredient contained in the supplied liquid within the target's epidermis with a compact configuration.

[0108] Furthermore, in the first embodiment, the positions at which the microneedles 225 are formed are determined at equal intervals on the circumference CIR of radius r based on the above-described formulas (1), (2), and (6). Therefore, the positions at which the microneedles having through-holes are formed can be appropriately determined, taking into consideration the constraints on the arrangement of the microneedles 225.

[0109] [Modifications of the First Embodiment] The present invention is not limited to the first embodiment described above, and various modifications are possible.

[0110] For example, in the first embodiment described above, the number of microneedles 225 on the circumference of a circle with a radius r1 was set to the maximum number that could be arranged at equal intervals using equation (6). However, the number of arrangements can be any number as long as it is equal to or less than the maximum number.

[0111] In the first embodiment, the shape of the microneedle 225, including the through-hole, is the same as that of the conventional example. However, the shape may be different from that of the conventional example.

[0112] In the first embodiment, the cylindrical base 221 is formed in the center of the exit-side end face of the cap member 220A, and the annular base 222 is formed on the outer periphery. However, it is possible to eliminate one or both of these two bases.

[0113] In the first embodiment described above, the electrical configuration of the diffusion facilitation device only describes the presence of a battery unit. However, the diffusion facilitation device may further include a battery unit, a switch element for switching between electrical connection and non-connection with the first electrode or the second electrode, a control element for turning the switch element on and off, a switch instruction input button for issuing an instruction to switch the switch element on and off to the control element, and a display element such as an LED for displaying the on / off state of the switch element.

[0114] The device may further include a control element and a display element that detect and display the remaining battery level.The device may further include a control element and a display element that detect and display the remaining amount of liquid.

[0115] In the first embodiment, the current flowing between the first electrode and the second electrode is assumed to be a direct current, but the current may be a pulse current.

[0116] In the first embodiment described above, the first electrodes are arranged in two locations (one of both surfaces of the shaft portion 110 in the X direction in FIG. 1 , the surface closer to the +Z direction, and the other of both surfaces closer to the −Z direction). In contrast, the first electrodes may be arranged in one location (one of both surfaces of the shaft portion 110 in the X direction in FIG. 1 , the surface closer to the +Z direction, or the surface closer to the −Z direction).

[0117] In the first embodiment, the surface closer to the +Z direction of both surfaces of the second electrode in the Z direction is flat. Alternatively, the surface closer to the +Z direction of the second electrode may be uneven (including cases where the convex portions are columnar). Examples of columnar convex portions include cases where multiple columnar bases are formed to form a comb-like shape. By employing such a comb-shaped second electrode, it is possible to preferably achieve iontophoresis of an active ingredient contained in a liquid formulation supplied to the scalp where hair grows, for example.

[0118] In the first embodiment, the active ingredient in the liquid formulation is assumed to be negatively ionized, and the anode and first electrodes of the battery unit are electrically connected directly or indirectly, and the cathode and second electrodes of the battery unit are electrically connected directly or indirectly. In contrast, if the active ingredient in the liquid formulation is positively ionized, the anode and second electrodes of the battery unit may be electrically connected directly or indirectly, and the cathode and first electrodes of the battery unit may be electrically connected directly or indirectly.

[0119] In the first embodiment, a human is assumed to be the target of iontophoresis, but the present invention may be applied to iontophoresis of a target other than a human.

[0120] Second Embodiment Next, an iontophoresis system 300B, a liquid drug supply device 200B, and a cap member 220B according to a second embodiment of the present invention will be described with reference mainly to FIGS.

[0121] The iontophoresis system 300B differs from the iontophoresis system 300A of the first embodiment only in that it includes a liquid agent supply device 200B instead of the liquid agent supply device 200A. The liquid agent supply device 200B also differs from the first embodiment only in that it includes a cap member 220B instead of the cap member 220A. Therefore, the following description will focus mainly on the cap member 220B. Explicit illustrations of the iontophoresis system 300B and the liquid agent supply device 200B will be omitted.

[0122] <Configuration of Cap Member 220B> FIGS. 11 and 12 show the configuration of the cap member 220B.

[0123] As shown comprehensively in Figures 11 (A) to (C), cap member 220B differs from the above-mentioned cap member 220A in that, in addition to multiple microneedles 225 protruding in the Z direction, multiple (four in the second embodiment) microneedles 226 having a protruding height H equivalent to that of the microneedles 225 are formed on the emission side end face 220BS, which is equivalent to the emission side end face 220AS of cap member 220A, and in that a cylindrical base 221 is not formed.

[0124] As shown in FIG. 11(C), the diameter of the through hole of the microneedle 226 is "d21". Also, as shown in FIG. 11(C), the microneedle 226 has an emission side end surface 220BS as the end surface in the +Z direction. As with the microneedle 225 described above, the flat plate-like portion of the thickness "T" has a so-called truncated cone-shaped back hole formed in the -Z direction of the formation position in the XY plane of each microneedle 226. Of the two truncated cone-shaped bottom surfaces in the Z direction of this back hole, the diameter of the bottom surface closer to the +Z direction is "d22 (> d21)", and the diameter of the bottom surface closer to the -Z direction (i.e., the opening of the back hole) is "d23 (> d22). The through hole with the diameter "d21" described above extends from the tip of the microneedle 226 in the +Z direction to the back hole.

[0125] When manufacturing the cap member 220B, a resin material (e.g., polypropylene) is first injected into the internal space of a mold to produce a pre-through-hole formation member having the same external shape as the cap member with the through-holes filled in. Subsequently, through-holes are formed by laser ablation, which is performed by irradiating a laser from the +Z direction onto the +Z-direction tips of the portions that will become the microneedles 225 and 226. In this way, the cap member 220B is manufactured.

[0126] Here, as shown in FIG. 11(A), all of the microneedles 226 are arranged at equal intervals on an imaginary circumference CIR2 that is centered on a central point CP and indicates the reference position of the microneedles 226.

[0127] <Arrangement of Microneedles 226> Next, the arrangement of the microneedles 226 will be described with reference to FIG.

[0128] In the second embodiment, the radius r2 of the circumference CIR2 centered at the above-mentioned center point CP is calculated by the following equation (4): r2=R-((D1 / 2)+(D2 / 2)) (4) (Here, the first shortest distance between the microneedles 225 determined from the constraints imposed when forming the microneedles 225 is defined as distance D1, and the second shortest distance between the microneedles 226 determined from the constraints imposed when forming the microneedles 226 is defined as distance D2.)

[0129] If the radius r2 calculated by equation (4) is less than the second shortest distance (D2 / 2), the formation of the microneedle 226 is abandoned.

[0130] Next, the number N2 of the microneedles 226 arranged on the circumference CIR2 is determined so as to satisfy the condition of the following formula (7): 2r2·sin(2π / N2)≧(D2)>2r2·sin(2π / (N2+1)) (7)

[0131] According to the number of arrangements N2 thus determined, the central angle θ2 (= 2π / N 12 ), that is, the arrangement positions of the microneedles 226 at a distance G2 (=2r2·sin(2π / N2)) between the microneedles 226 are determined.

[0132] In the second embodiment, the radius (d21 / 2) of the through-holes of the microneedles 226 is determined so that the first total ejection amount Q1 of the liquid from all the microneedles 225 in response to one knock operation of the knock section 230 is equal to the second total ejection amount Q2 of the liquid from all the microneedles 226. When determining this radius (d21 / 2), first, the ratio RT of the evaluated value of the first inflow velocity V1 of the liquid into the microneedles 225 and the evaluated value of the second inflow velocity V2 of the liquid into the microneedles 226 is estimated.

[0133] This estimation is based on the fact that it is reasonable to assume that the liquid is an incompressible Newtonian fluid and that the liquid is in a laminar steady flow, i.e., a Hagen-Boiseuille flow, in the circular tubular flow path immediately before it flows into the microneedles 225 and 226. Under this assumption, the first inflow velocity V1 and the second inflow velocity V2 are evaluated by the following equations (8) and (9).

[0134] V1 = k (R FL 2 -r1 2 ) …(8) V2=k・(R FL 2 -r2 2 ) (9) where k is a constant.

[0135] As a result, the ratio RT is calculated by the following equation (10): RT = V2 / V1 = (R FL 2 -r2 2 ) / (R FL 2 -r1 2 ) … (10)

[0136] When the first total injection amount Q1 and the second total injection amount Q2 are equal to each other, the following formula (11) holds: Q1 = N1 π (d1 1 / 2) 2 ・V1 =Q2=N2・π・(d21 / 2) 2 V2 ... (11)

[0137] Therefore, the relationship between the radius (d21 / 2) of the through-hole of the microneedle 226 and the radius (d11 / 2) of the through-hole of the microneedle 225 is considered to be expressed by the following formula (12): (d21 / 2) = ((N1 / N2) / RT) 1 / 2 (d11 / 2) (12) Therefore, in the second embodiment, the diameter d21 is determined based on the diameter d11 using the formula (12).

[0138] As described above, the iontophoresis system 300B and the liquid agent supply device 200B of the second embodiment differ only in that the cap member 220B is used instead of the cap member 220A used in the first embodiment. Therefore, the iontophoresis system 300B and the liquid agent supply device 200B operate in the same manner as the iontophoresis system 300A and the liquid agent supply device 200A of the first embodiment, except that the amount of liquid agent ejected to the outside increases in response to a single knocking operation on the knock portion 230 of the liquid agent supply device 200B (and thus a single knocking operation (pressing operation) on the pressing member 130 of the iontophoresis system 300B).

[0139] As described above, in the cap member 220B of the second embodiment, in addition to the microneedles 225, the microneedles 226 are formed on the emission-side end surface 220BS, and therefore, it is possible to appropriately arrange the microneedles while increasing the number of microneedles having through holes, taking into consideration the limit on the arrangement density of the microneedles 225 and 226. Furthermore, it is possible to equalize the amount of the liquid agent in each of the regions corresponding to the vicinity of the two types of circumference of the target to which the liquid agent is to be supplied.

[0140] Furthermore, in the cap member 220B, the number N2 of microneedles 226 arranged on the circumference CIR2 is set to the maximum number that can be arranged so as to satisfy the condition of the above-mentioned formula (7). This makes it possible to maximize the ejection area of ​​the liquid agent when the microneedles are arranged at equal intervals on the circumference CIR2, which can contribute to reducing the pressing force on the liquid agent for ejecting the liquid agent.

[0141] Furthermore, in the cap member 220B, the diameters of the microneedles 226 are determined so that the first total amount of the liquid ejected from all the microneedles 225 is equal to the second total amount of the liquid ejected from all the microneedles 226, based on the ratio between the evaluation value of the first inflow velocity V1 of the liquid into the microneedles 225 and the evaluation value of the second inflow velocity V2 of the liquid into the microneedles 226, and the ratio between the number of the microneedles 225 and the number of the microneedles 226. This makes it possible to make the amounts of the liquid supplied to regions corresponding to the vicinity of each of the two types of circumference in the supply target equal to each other.

[0142] Furthermore, in the cap member 220B, the first inflow velocity V1 and the second inflow velocity V2 are evaluated by applying the Hagen-Poiseuille law, which allows the first inflow velocity V1 and the second inflow velocity V2 to be evaluated rationally.

[0143] In the second embodiment, the amounts of liquid supplied to the regions of the target corresponding to the two circumferences are equal, and the amount of liquid supplied per unit area to the inner circumferential region is greater than the amount of liquid supplied per unit area to the outer circumferential region. Here, the iontophoresis action in response to the generation of a weak current between second electrode 125, which is located outside the outer circumference, and first electrodes 115 and 115, can be said to be more efficient in the outer circumferential region than in the inner circumferential region. Therefore, it is possible to level the diffusion pattern of the active ingredient of the liquid corresponding to the epidermal regions corresponding to the two circumferences of the target into the target.

[0144] Furthermore, in the cap member 220B, an annular base 222 is formed on the outer periphery of the injection-side end face, with a maximum height approximately equal to the protruding height of the microneedles 225, 226 from the injection-side end face. In this case, the annular base 222 functions as a "non-slip" that prevents the microneedles 225 from shifting (so-called "lateral shifting") on the epidermis of the target to be supplied. This makes it possible to stabilize the supply positions of the microneedles 225, 226 on the epidermis of the target to be supplied when supplying the liquid agent.

[0145] Furthermore, solution supply device 200B is configured to include cap member 220B. Therefore, when a pressing force is applied to the solution contained in solution storage space LS of shaft portion 210, the solution is ejected from through-holes of microneedles 225, 226 formed in cap member 220B after passing through connecting portion 250. Therefore, it is possible to reduce the pressing force on the solution for ejecting the solution compared to the first embodiment, while also making the amount of the solution uniform over the circumferential region of the epidermis of the supply target.

[0146] Furthermore, in the iontophoresis system 300B, when a liquid is supplied or being supplied to a target from the cap member 220B of the liquid supply device 200B housed in the internal storage space CS, a current path is formed between the first electrode 115 and / or 115 and the second electrode 125 through the target's epidermis, promoting diffusion of the active ingredient contained in the liquid within the target's epidermis (e.g., the stratum corneum). That is, the iontophoresis effect promotes diffusion of the liquid within the target's epidermis. Therefore, the diffusion promoting device 100 can promote diffusion of the active ingredient contained in the supplied liquid within the target's epidermis with a compact configuration.

[0147] [Modifications of the Second Embodiment] The present invention is not limited to the second embodiment described above, and various modifications are possible.

[0148] For example, in the second embodiment described above, the number of microneedles 226 on the circumference of a circle with a radius r is set to the maximum number that can be arranged at equal intervals using equation (7). However, the number of arrangements can be any number as long as it is equal to or less than the maximum number.

[0149] In the second embodiment, the first inflow velocity V1 and the second inflow velocity V2 are evaluated by applying the Hagen-Poiseuille law. However, the first inflow velocity V1 and the second inflow velocity V2 can also be evaluated by experiment, simulation, and experience.

[0150] In the second embodiment, the annular base 222 is formed on the outer periphery of the exit-side end face of the cap member 220B. However, it is also possible to omit the annular base 222, or to form a cylindrical base in the center. Furthermore, it is also possible to form a new annular base between two different circumferences.

[0151] In the second embodiment, the radius r is calculated using the above-mentioned formula (4). However, the radius r can be set to any length as long as it satisfies the condition of the above-mentioned formula (3).

[0152] In the second embodiment, the first total ejection amount Q1 and the second total ejection amount Q2 are equal. Alternatively, the radius (d21 / 2) of the through-hole of the second microneedle may be determined so that the first individual ejection amount of the liquid from the first microneedle and the second individual ejection amount of the liquid from the second microneedle are equal. In this case, the amount of the liquid can be equalized within the region within the first circumference of the target to which the liquid is to be supplied.

[0153] In this case, the radius (d21 / 2) of the through-hole of the second microneedle can be calculated based on the diameter d11 using the ratio RT calculated by the above-mentioned formula (10) and the following formula (13): (d21 / 2) = (d11 / 2) / RT 1 / 2 …(13)

[0154] Moreover, the diffusion promoting device of the second embodiment can be modified in the same manner as the first embodiment.

[0155] In the first and second embodiments, the microneedles are shaped like truncated cones. Alternatively, as shown in FIG. 13, the tips of the microneedles may be cut off at a plane oblique to the Z axis. FIG. 13(A) shows a modified shape of the microneedle 225, and FIG. 13(B) shows a modified shape of the microneedle 226. This modified shape can facilitate, for example, the direct delivery of a liquid agent to the stratum corneum of human skin.

[0156] In the first embodiment described above, the only type of microneedle formed was the microneedle 225 with a through hole. Alternatively, as shown comprehensively in FIGS. 14 and 15 , solid microneedles 227 without a through hole may also be formed. In the cap member 220C shown in FIGS. 14 and 15 , a cylindrical base 221C having a protruding height "H1" lower than the protruding height "H" of the microneedle 225 described above and an annular base 222C having a protruding height "H1" are formed in the center of the emission-side end surface 220AS. A plurality of solid microneedles 227 with a protruding height "H" are formed on the cylindrical base 221C and the annular base 222C. Therefore, the maximum height of the solid microneedle 227 in the +Z direction is higher than the maximum height of the microneedle 225 in the +Z direction.

[0157] When viewed in the −Z direction, the solid microneedles 227 are arranged along a straight line extending from the center CP toward the center positions of the microneedles 225. Furthermore, the outer diameter of the solid microneedles 227 formed on the cylindrical base 221C can be slightly larger than that of the solid microneedles 227 formed on the annular base 222C.

[0158] 16 shows the state when the cap member 220C is pressed against an elastic target OBJ, such as human epidermis. As shown in Fig. 16, the tip of the microneedle 225 abuts against a portion of the target OBJ that bulges in the -Z direction due to the pressing of the solid microneedle 227. As a result, when the cap member 220C is pressed against a person's epidermis to supply the liquid agent, the person can effectively experience a sensation of use (a tingling sensation).

[0159] In the cap member 220C, the solid microneedles 227 are formed on the cylindrical base 221C and the annular base 222C, but the formation of the cylindrical base 221C and / or the annular base 222C may be omitted. Even in this case, in order to effectively generate a feeling of use (tingling sensation), it is preferable that the maximum height of the solid microneedles 227 in the +Z direction is higher than the maximum height of the microneedles 225 in the +Z direction.

[0160] 14, the cap member 220C has a cylindrical base 221C and annular base 222C that are separated from each other on the emission-side end surface 220AS. However, as in the cap member 220D shown in FIG. 17, a base 223 may be formed in which the cylindrical base 221C and the annular base 222C are connected via a base portion formed between adjacent microneedles 225. Then, solid microneedles 227 are formed on the base 223 at the same XY positions as in the case of the cap member 220C. Therefore, as in the case of the cap member 220C, the cap member 220D allows the user to effectively feel a sensation of use (tingling sensation) similar to when the cap member 220C is pressed against the user's epidermis to supply a liquid agent.

[0161] While only solid microneedles 227 are formed on the base 223 of the cap member 220C shown in Fig. 17, a plurality of patterned patterns 228 can also be formed, as in the cap member 220E shown in Fig. 18. Here, the maximum height of the patterned patterns 228 in the +Z direction is lower than the maximum height of the microneedles 225 in the +Z direction. When viewed in the -Z direction, the cap member 220E can give the user a more aesthetically pleasing design than the cap member 220D.

[0162] In the cap member 220E of FIG. 18, the design pattern 228 has a V-shape, but may have other shapes.

[0163] The present invention is useful in the field of liquid drug delivery, in which a liquid drug containing an active ingredient is delivered to the epidermis of a target, and can also be used in the field of iontophoresis, in which the active ingredient contained in the liquid drug is diffused inside the epidermis of a target.

[0164] REFERENCE SIGNS LIST 100 diffusion promoting device 110 first cylindrical member 1151, 1152 first electrode 120 second cylindrical member 123 elastic member 125 second electrode 130 pressing member 190 battery unit

[0165] 200A, 200B... Liquid agent supply device 210... Shaft portion 211... Large diameter portion 212... Small diameter portion 220A to 220E... Cap member 220AS, 220BS... Injection side end surface 221... Cylindrical base 222... Annular base 223... Base 225... Microneedle (first microneedle) 226... Microneedle (second microneedle) 227... Solid microneedle 228... Design pattern

[0166] 230: Knocking portion 240: Liquid agent extrusion portion 241: Fixed amount moving portion 242: Shaft 243: Piston 246: Main body portion 247: Convex portion 250: Connecting portion 300A, 300B: Iontophoresis system

[0167] CIR1 ... Circumference (first circumference) CIR2 ... Circumference (second circumference) CS ... Storage space CS1 ... First storage space (part of storage space CS) CS2 ... Second storage space (part of storage space CS) CS3 ... Third storage space LS ... Liquid agent storage space OP1 ... First through-hole OP2 ... Second through-hole

Claims

1. A cap member provided in a liquid drug supply device that injects a liquid drug containing an active ingredient to the outside and supplies it to the epidermis of a target, and that is placed on an end of the liquid drug supply device in an injection direction of the liquid drug, wherein the cap member has a cylindrical shape with a bottom that is open on the side opposite to the injection direction, wherein a through-hole for injecting the liquid drug to the outside is formed on the injection side end face of the cap member and a plurality of microneedles are arranged protruding in the injection direction, wherein the plurality of microneedles include a first number of first microneedles that are arranged on a first circumference centered on the center point of the injection side end face, wherein the amounts of the liquid drug ejected from each of the first number of first microneedles in response to a pressing force in the injection direction are equal to each other, and wherein the radius r1 of the first circumference satisfies the following formula (1): r1≦R-(D1 / 2) ... (1) (Here, a first distance that should be secured as the distance between the central positions of the first number of first microneedles adjacent to each other on the emission side end face is defined as distance D1, and the inner radius of the cap member is defined as R, and the distance is determined according to constraints when producing the first number of first microneedles and the strength of the cap member against the pressing force.) The radius r1 further satisfies the following formula (2): R - (L / 2) ≦ r1 ... (2) (Here, when the distance between the central positions of the first number of first microneedles adjacent to each other on the emission side end face is equal to or greater than the first distance D1, and the number of first microneedles arranged on the first circumference is maximized, the arc length on the first circumference between two adjacent first number of first microneedles is defined as L.) A cap member characterized in that all of the distances between the central positions of the first number of first microneedles on the emission side end face are equal to or greater than the first distance D1.

2. The cap member described in claim 1, characterized in that each of the first number of first microneedles has an equivalent shape to the others, and the first number is the maximum number of first microneedles that can be arranged at equal intervals on the first circumference.

3. The cap member described in claim 1, characterized in that at least one cylindrical base is formed on the inside of the first circumference of the injection side end face so as to protrude in the injection direction, with a maximum height equal to the protruding height from the injection side end face of each of the first number of first microneedles.

4. A cap member as described in claim 1, characterized in that a platform having a maximum height equal to the protruding height from the injection side end face of each of the first number of first microneedles and having an annular shape when viewed from the injection direction is formed on the outside of the first circumference of the injection side end face so as to protrude in the injection direction.

5. The cap member described in claim 1, further comprising at least one solid microneedle extending along a straight line extending from the center point of the ejection side end face in a direction toward each of the first number of microneedles to a height position higher than the height of protrusion of the first microneedle from the ejection side end face in the ejection direction, and protruding in the ejection direction.

6. The cap member described in claim 4, characterized in that the emission side end surface further has a base formed in at least a portion of an area other than the area where the first number of first microneedles are arranged, the base having a protruding height lower than the protruding height of the first microneedles from the emission side end surface in the emission direction, and the at least one solid microneedle is arranged on the base.

7. The plurality of microneedles include a second number of second microneedles that are arranged in an inner region of the first circumference, have through holes formed therein for ejecting the liquid agent to the outside, and have a protruding height equivalent to that of the first microneedles, the amounts of the liquid agent ejected from each of the second number of second microneedles in response to a pressing force in the ejection direction are equivalent to each other, and the central positions of the second microneedles on the ejection side end face are all separated by a distance equal to or greater than a second distance D2 (here, the second distance to be secured between adjacent second number of second microneedles, which is determined according to constraints in manufacturing the second number of second microneedles and the strength of the cap member against the pressing force, is defined as distance D2). The distance D between the central positions of the second number of second microneedles on the ejection side end face and the central positions of the corresponding first number of first microneedles on the ejection side end face is 12 All of these satisfy the following formula (3): 12 2. The gap member according to claim 1, wherein the following relationship is satisfied: ≧(D1 / 2)+(D2 / 2) (3).

8. The cap member according to claim 7, wherein the second number of second microneedles are arranged on a second circumference in an area inside the first circumference.

9. The cap member according to claim 8, wherein the center of the second circumference and the center of the first circumference coincide with each other, and the radius r2 of the second circumference is selected to satisfy the following formula (4): r1 - [(D1 / 2) + (D2 / 2)] ≥ r2 ≥ (D2 / 2) ... (4).

10. The cap member described in claim 9, characterized in that each of the second number of second microneedles has an equivalent shape to the others, and the second number is the maximum number of the second microneedles that can be arranged at equal intervals on the second circumference.

11. A cap member as described in claim 10, characterized in that the ratio between the diameter of the through hole of each of the first number of first microneedles and the diameter of the through hole of each of the second number of second microneedles is determined so that the first individual ejection amount of the liquid from each of the first number of first microneedles and the second individual ejection amount of the liquid from each of the second number of second microneedles are equivalent to each other, based on the ratio between a first inflow speed V1 of the liquid into each of the first number of first microneedles and a second inflow speed V2 of the liquid into each of the second number of second microneedles.

12. The cap member described in claim 10, wherein the ratio between the diameter of the through hole of each of the first number of first microneedles and the diameter of the through hole of each of the second number of second microneedles is determined based on the ratio between a first inflow velocity V1 of the liquid into each of the first number of first microneedles and a second inflow velocity V2 of the liquid into each of the second number of second microneedles, and the ratio between the first number and the second number, so that a first total amount of the liquid ejected from all of the first microneedles and a second total amount of the liquid ejected from all of the second microneedles are equivalent to each other.

13. A cap member as described in claim 11 or 12, characterized in that the first inflow velocity V1 and the second inflow velocity V2 are evaluated by applying the Hagen-Poiseuille law based on the shape of the cylindrical flow path through which the liquid material is pressed toward the injection side end face.

14. A liquid drug supply device comprising the cap member according to claim 1, further comprising: a shaft portion in which a liquid drug storage space for storing the liquid drug is formed along the injection direction; and a connecting portion disposed at an end of the shaft portion in the injection direction, connecting the shaft portion to the cap member.

15. A liquid drug supply device according to claim 14 and a diffusion promotion device, wherein the diffusion promotion device comprises a first cylindrical member, a second cylindrical member, a first electrode, a second electrode, and a battery unit; the first cylindrical member has a first storage space formed therein extending along the injection direction and storing a first predetermined portion of the liquid drug supply device on the opposite side; the second cylindrical member has a first through-hole formed therein, disposed in the injection direction of the first cylindrical member, through which the cap member can be passed along the injection direction but the shaft portion cannot be passed along the injection direction, and a second storage space formed therein for storing a second predetermined portion of the liquid drug supply device on the injection direction side; the first electrode is used to promote diffusion of an active ingredient; the second electrode forms a current path between the first electrode and the second electrode through the inside of the epidermis of the supply target when the active ingredient is diffusing; the battery unit generates a predetermined potential difference between the first electrode and the second electrode, The iontophoresis system, wherein the first storage space and the second storage space form a storage space for the liquid drug supply device.

16. A method for designing microneedle placement positions in a bottomed cylindrical cap member provided in a liquid drug supply device that injects a liquid drug containing an active ingredient to the outside and supplies it to the epidermis of a target, the cap member being disposed at the injection direction end of the liquid drug supply device, the cap member having a through-hole formed therein for injecting the liquid drug, and the cap member having a plurality of microneedles of identical shapes disposed on the injection side end face; the method comprising: a radius calculation step of calculating the radius r of a circumference of a circle whose center is the center point of the injection side end face on which the centers of the plurality of microneedles are disposed, the radius r satisfying the following formula (5): R-(L / 2)≦r≦R-(D / 2) ... (5) (Here, distance D is the distance that should be secured as the distance between the center positions of the microneedles on the injection side end face, which is determined depending on the constraints when manufacturing the microneedles and the strength of the cap member against the pressing force, the inner radius of the cap member is R, and the distance between the center positions of the microneedles on the injection side end face is set to be equal to or greater than distance D, and when the number of microneedles arranged when equally spaced on the circumference is maximized, the arc length on the circumference between the center positions of two adjacent microneedles is set to L.) A method for designing microneedle arrangement positions, comprising: an arrangement position determination step of determining positions at which the microneedles are to be arranged at equal intervals on the circumference while separating any two of the microneedles by the distance D or more.

Images