Patent Publication Number: US-2020276428-A1

Title: Manufacturing method of microneedle array

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority under 35 U.S.C § 119 to Japanese Patent Application No. 2019-036376 filed on Feb. 28, 2019, which is hereby expressly incorporated by reference, in its entirety, into the present application. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a manufacturing method of a microneedle array, and more particularly to a manufacturing method of a microneedle array in which a drug solution is ejected from an ejection nozzle into a recessed portion of a mold. 
     2. Description of the Related Art 
     In recent years, a microneedle array (percutaneous absorption sheet) formed with needle-like protruding portions (also referred to as small needles or microneedles) containing a drug has been used to deliver the drug into the skin. In general, by pressing the microneedle array against the skin to insert the needle-like protruding portions into the skin, the drug of the needle-like protruding portions is delivered into the skin. 
     As a method of manufacturing the microneedle array, a mold in which needle-like recessed portions having an inverted shape of the needle-like protruding portions is formed. A method of forming a microneedle array by filling needle-like recessed portions of a mold with a solution containing a drug (also referred to as a drug solution), drying the solution, applying a solution not containing the drug (also referred to as a base material solution), and drying the solution is known. 
     In the method of manufacturing the microneedle array, since the filling amount of the drug solution is associated with the drug dose, it is necessary to reliably fill the needle-like recessed portions of the mold with a very small amount of the drug solution in a constant amount with high accuracy. 
     Hitherto, a method for filling a drug solution has been proposed (refer to JP2016-112169A). 
     SUMMARY OF THE INVENTION 
     JP2016-112169A discloses a filling method in which liquid droplets are ejected from an ejection nozzle into needle-like recessed portions of a mold. However, when the filling is performed at a high velocity in order to increase the productivity, there is a problem that the landing position of the liquid droplet and the position of the needle-like recessed portion deviate from each other. 
     Such a positional deviation is caused by a landing positional deviation due to apparatus vibration that occurs when a stage or an ejection nozzle is moved at a high velocity, a landing positional deviation due to a change in liquid droplet flight velocity caused by a state change in the ejection nozzle over time and a change in a drug solution over time, a positioning deviation during mold installation, a positional deviation of needle-like recessed portions due to expansion and contraction or strain of the mold itself, and combinations thereof. It is practically difficult to eliminate these factors and completely prevent the positional deviation. 
     In a case where the drug solution deviates from the center portion of the needle-like recessed portion or the drug solution adheres to the wall surface of the needle-like recessed portion due to the positional deviation described above and thus the drug solution cannot close the needle-like recessed portion, the drug solution cannot fill the distal end of the needle-like recessed portion, and there is a problem that the manufacturing yield (yield) of a microneedle array is reduced. 
     The present invention has been made taking the above circumstances into consideration, and an object thereof is to provide a manufacturing method of a microneedle array in which the distal end of a needle-like recessed portion can be filled with a drug solution even in a case where a positional deviation between a landing position of a liquid droplet and the needle-like recessed portion occurs. 
     A manufacturing method of a microneedle array according to a first aspect comprises: an adjustment step of positioning and adjusting a mold having a first surface and a second surface, which oppose each other, and a plurality of needle-like recessed portions in the first surface, and an ejection nozzle which ejects a drug solution in a first direction; a relative movement step of moving the mold and the ejection nozzle relative to each other to cause a position of the needle-like recessed portion and a position of the ejection nozzle to coincide with each other in a plan view in the first direction; an ejection step of ejecting the drug solution from the ejection nozzle toward the needle-like recessed portion; a vibration step of vibrating the mold to move the drug solution toward the needle-like recessed portion and close the needle-like recessed portion with the drug solution after the ejection step; and a suction step of suctioning the second surface of the mold. 
     According to the first aspect, the drug solution closes the needle-like recessed portion, and fills the needle-like recessed portion by suction. The manufacturing yield of the microneedle array is improved. 
     In the manufacturing method of a microneedle array according to a second aspect, the vibration in the vibration step is a horizontal reciprocating motion. In the second aspect, the vibration of the horizontal reciprocating motion can be applied to the mold. 
     In the manufacturing method of a microneedle array according to a third aspect, a movement direction of the drug solution and a direction of the horizontal reciprocating motion are the same direction. In the third aspect, in the horizontal reciprocating motion, the drug solution can be moved to the needle-like recessed portion and close the needle-like recessed portion more reliably within a short period of time. 
     In the manufacturing method of a microneedle array according to a fourth aspect, the vibration in the vibration step is a horizontal circular motion. In the fourth aspect, the vibration of the horizontal circular motion can be applied to the mold. 
     In the manufacturing method of a microneedle array according to a fifth aspect, the vibration in the vibration step is a vertical reciprocating motion. In the fifth aspect, the vibration of the vertical reciprocating motion can be applied to the mold. 
     In the manufacturing method of a microneedle array according to a sixth aspect, the vibration in the vibration step further includes a vertical reciprocating motion. In the sixth aspect, the vibration of a combination of the horizontal reciprocating motion and the vertical reciprocating motion can be applied to the mold. 
     In the manufacturing method of a microneedle array according to a seventh aspect, the vibration in the vibration step further includes a vertical reciprocating motion. In the seventh aspect, the vibration of a combination of the horizontal circular motion and the vertical reciprocating motion can be applied to the mold. 
     In the manufacturing method of a microneedle array according to an eighth aspect, the needle-like recessed portion comprises: a cup portion provided in the first surface of the mold; and a distal end recessed portion which is connected to the cup portion and has a tapered shape in a depth direction of the mold, an edge portion of an opening of the needle-like recessed portion is chamfered, and a chamfer of the edge portion has a radius of curvature of 30 μm or more and 300 μm or less. In the eighth aspect, the drug solution that has landed on the edge portion can be collected in the needle-like recessed portion. 
     In the manufacturing method of a microneedle array according to a ninth aspect, the vibration in the vibration step has an amplitude of 1 mm or more and 10 mm or less, a frequency of 15 Hz or higher and 100 Hz or lower, and a time of 1 second or longer and 180 seconds or shorter. In the ninth aspect, by setting the amplitude, frequency, and time of the vibration to the above-described ranges, the drug solution can be moved to the needle-like recessed portion and close the needle-like recessed portion more reliably. 
     The manufacturing method of a microneedle array according to a tenth aspect, further comprises: after the suction step, a drug solution drying step of drying the drug solution filling the needle-like recessed portion; after the drug solution drying step, a base material solution filling step of filling the mold with a base material solution; and a base material solution drying step of drying the filled base material solution. In the tenth aspect, the microneedle array containing the drug solution can be manufactured. 
     According to the present invention, since the drug solution can be moved to the needle-like recessed portion and close the needle-like recessed portion, the distal end of the needle-like recessed portion of the mold can be filled with the drug solution, thereby improving the manufacturing yield of the microneedle array. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view illustrating a schematic configuration of a microneedle array. 
         FIG. 2  is an enlarged partial cross-sectional view of the microneedle array. 
         FIG. 3  is a perspective view illustrating an example of a mold. 
         FIG. 4  is a cross-sectional view taken along line Iv-Iv in  FIG. 3 . 
         FIG. 5  is a flowchart showing each step of a manufacturing method of a microneedle array. 
         FIG. 6  is a schematic configuration diagram of a drug solution filling apparatus used in a drug solution filling step. 
         FIG. 7  is a block diagram illustrating an electrical configuration of the drug solution filling apparatus. 
         FIG. 8  is a flowchart showing each step included in the drug solution filling step. 
         FIG. 9  is a schematic view illustrating a part of the steps included in the drug solution filling step. 
         FIG. 10  is a schematic view illustrating a part of the steps included in a drug solution filling step. 
         FIG. 11  is a schematic view illustrating a part of the steps included in the drug solution filling step. 
         FIG. 12  is a schematic view illustrating a part of the steps included in the drug solution filling step. 
         FIG. 13  is a schematic view illustrating a vibration step included in the drug solution filling step. 
         FIG. 14  is a schematic view illustrating the vibration step included in the drug solution filling step. 
         FIG. 15  is a schematic view illustrating the vibration step included in the drug solution filling step. 
         FIG. 16  is a schematic view illustrating the vibration step included in the drug solution filling step. 
         FIG. 17  is a schematic view illustrating the vibration step included in the drug solution filling step. 
         FIG. 18  is a schematic view illustrating the vibration step included in the drug solution filling step. 
         FIG. 19  is a schematic view illustrating the vibration step included in the drug solution filling step. 
         FIG. 20  is a waveform diagram showing an example of vibration. 
         FIG. 21  is a waveform diagram showing another example of the vibration. 
         FIG. 22  is a waveform diagram showing another example of the vibration. 
         FIG. 23  is a cross-sectional view for describing the shape of a needle-like recessed portion according to an example. 
         FIG. 24  is a table showing parameters at each level and evaluation results thereof. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The present invention is described by the following preferred embodiments. Modifications can be made by various methods without departing from the scope of the present invention, and other embodiments than the embodiments can also be used. Therefore, all modifications within the scope of the present invention are included in the appended claims. 
     Here, in the figures, like elements having similar functions are denoted by like reference numerals. In addition, in this specification, in a case where a numerical value range is expressed using “to”, the numerical value range includes the numerical values of the upper limit and the lower limit indicated by “to”. 
     Microneedle Array 
     An example of a microneedle array (percutaneous absorption sheet) manufactured by a manufacturing method in the present embodiment will be described. 
       FIG. 1  is a perspective view illustrating an example of a microneedle array  100 . The microneedle array  100  corresponds to a patch for one administration. The microneedle array  100  comprises a sheet portion  102  having a first surface  102 A and a second surface  102 B which oppose each other, and needle-like protruding portions  112  arranged on the first surface  102 A of the sheet portion  102 . 
     The sheet portion  102  has a thin flat shape as a whole with respect to the two opposing first and second surfaces  102 A and  102 B having a large area. Although the sheet portion  102  illustrated in  FIG. 1  is circular in a plan view, the sheet portion  102  may be rectangular, polygonal, elliptical, or the like. Here, the plan view means a state in which the first surface  102 A is observed in a direction orthogonal to the first surface  102 A. 
     A plurality of the needle-like protruding portions  112  are arranged on the first surface  102 A of the sheet portion  102  in a predetermined pattern. The plurality of arranged needle-like protruding portions  112  constitute an array pattern  110 . For example, the array pattern  110  can be configured by arranging the plurality of needle-like protruding portions  112  in a concentric shape, and can also be configured by arranging the plurality of needle-like protruding portions  112  in a lattice shape. The array pattern  110  is not particularly limited and can be changed as appropriate. 
     The array pattern  110  is constituted by, for example, 4 to 2500 needle-like protruding portions  112 . However, the number of needle-like protruding portions  112  is not limited to this number. 
     The needle-like protruding portion  112  is configured in a shape having a narrow distal end as compared with the root in contact with the sheet portion  102 . Examples of the shape of the needle-like protruding portion  112  include a cone shape, a polygonal pyramid shape (such as a quadrangular pyramid shape), or a spindle shape. The overall shape of the needle-like protruding portion  112  may be a cone shape or a polygonal pyramid shape (such as a quadrangular pyramid shape), or may be a structure in which the inclination (angle) of the side surface of the needle portion is continuously changed. Alternatively, a multilayer structure of two or more layers in which the inclination (angle) of the side surface of the needle portion changes discontinuously may also be adopted. 
       FIG. 2  is an enlarged partial cross-sectional view of the microneedle array  100 . The needle-like protruding portion  112  includes a needle portion  114  on the distal end side and a frustum portion  116  on the root side. The needle-like protruding portion  112  has a so-called two-stage structure in which the inclination of the side surface of the needle portion  114  and the inclination of the side surface of the frustum portion  116  discontinuously change in appearance. 
     The frustum portion  116  has two bottom surfaces and has a three-dimensional structure surrounded by a conical surface. The bottom surface (lower bottom surface) of the two bottom surfaces of the frustum portion  116  having a large area is connected to the sheet portion  102 . The bottom surface (upper bottom surface) of the two bottom surfaces of the frustum portion  116  having a small area is connected to the needle portion  114 . That is, of the two bottom surfaces of the frustum portion  116 , the area of the bottom surface in a direction away from the sheet portion  102  is small. 
     The needle portion  114  has a bottom surface with a large area and a shape having a narrowest area at the distal end apart from the bottom surface. Since the bottom surface of the needle portion  114  having a large area is connected to the upper bottom surface of the frustum portion  116 , the needle portion  114  has a tapered shape in a direction away from the frustum portion  116 . 
     In the form of  FIGS. 1 and 2 , the needle portion  114  has a cone shape, and the frustum portion  116  has a truncated cone shape. However, the needle portion  114  and the frustum portion  116  are not limited to these shapes. Depending on the degree of insertion of the needle portion  114  into the skin, the shape of the distal end of the needle portion  114  can be appropriately changed to a curved surface, a flat surface, or the like. 
     For example, a columnar pedestal portion can be provided between the frustum portion  116  and the sheet portion  102 . In addition, a columnar intermediate portion can be provided between the needle portion  114  and the frustum portion  116 . 
     The height (length) of the needle-like protruding portion  112  is represented by the length of a segment from the distal end of the needle-like protruding portion  112  perpendicular to the sheet portion  102 . The height (length) of the needle-like protruding portion  112  is not particularly limited, but is preferably 350 μm or more and 2500 μm or less. 
     The microneedle array  100  is made of a first material M 1  containing a drug and a second material M 2  not containing the drug. The needle portion  114  has a distal end portion made of the first material M 1  and a root portion made of the second material M 2 . The frustum portion  116  and the sheet portion  102  are made of the second material M 2 . 
     Containing a drug means containing a drug in an amount that exhibits the drug effect in a case where the body surface is punctured. In addition, not containing a drug means not containing a drug in an amount that exhibits the drug effect. In a case of not containing a drug, the range of the amount of the drug is a range from 0, at which the drug is not contained at all, to the amount at which the drug effect is not exhibited. 
     The drug is not limited as long as the drug has a function as a drug. In particular, it is preferable to select from pharmaceutical compounds belonging to peptides, proteins, nucleic acids, polysaccharides, vaccines, and water-soluble low-molecular compounds. 
     The first material M 1  is not particularly limited, and examples thereof include polysaccharides, polyvinyl pyrrolidone, polyoxyethylene polyoxypropylene glycol, polyethylene glycol, polyvinyl alcohol, and proteins (for example, gelatin). Examples of the polysaccharides include hyaluronic acid, sodium hyaluronate, pullulan, dextran, dextrin, chondroitin sulfate, sodium chondroitin sulfate, cellulose derivatives (for example, water-soluble cellulose derivatives partially modified from cellulose, such as carboxymethyl cellulose, hydroxypropyl cellulose, and hydroxypropyl methylcellulose), hydroxyethyl starch, and gum arabic. The above components may be used singly or as a mixture of two or more. 
     Among the above components, the first material M 1  is preferably at least one selected from the group consisting of hydroxyethyl starch, dextran, chondroitin sulfate, sodium chondroitin sulfate, sodium hyaluronate, carboxymethyl cellulose, polyvinyl pyrrolidone, polyoxyethylene polyoxypropylene glycol, polyethylene glycol, and polyvinyl alcohol, and is particularly preferably sodium chondroitin sulfate. 
     The second material M 2  is not particularly limited, and examples thereof include polysaccharides, polyvinyl pyrrolidone, polyoxyethylene polyoxypropylene glycol, polyethylene glycol, polyvinyl alcohol, and proteins (for example, gelatin). Examples of the polysaccharides include hyaluronic acid, sodium hyaluronate, pullulan, dextran, dextrin, chondroitin sulfate, sodium chondroitin sulfate, cellulose derivatives (for example, water-soluble cellulose derivatives partially modified from cellulose, such as carboxymethyl cellulose, hydroxypropyl cellulose, and hydroxypropyl methylcellulose), hydroxyethyl starch, and gum arabic. The above components may be used singly or as a mixture of two or more. 
     Among the above components, the second material M 2  is preferably at least one selected from the group consisting of hydroxyethyl starch, dextran, chondroitin sulfate, sodium chondroitin sulfate, sodium hyaluronate, carboxymethyl cellulose, polyvinyl pyrrolidone, polyoxyethylene polyoxypropylene glycol, polyethylene glycol, and polyvinyl alcohol, and is particularly preferably sodium chondroitin sulfate. 
     The first material M 1  and the second material M 2  may be the same material or different from each other. 
     Manufacturing Method of Microneedle Array 
     Next, a manufacturing method of the microneedle array will be described with reference to the drawings. 
     As illustrated in  FIGS. 3 and 4 , in order to produce the microneedle array  100 , a mold  300  is prepared. The mold  300  has a first surface  300 A and a second surface  300 B which oppose each other. A plurality of needle-like recessed portions  310  are formed in the first surface  300 A of the mold  300 . 
     The mold  300  comprises a weir  320  which has a certain height on the first surface  300 A side where the needle-like recessed portions  310  are formed and surrounds the periphery of the needle-like recessed portions  310 . The mold  300  can be made of, for example, a silicone resin. A flat surface  330  is provided between the needle-like recessed portions  310  and the weir  320 . A recessed portion pattern  312  is constituted by the plurality of needle-like recessed portions  310 . 
     The material of the mold  300  is desirably a material excellent in gas permeability such as a silicone resin, a thermoplastic resin, and a photocurable resin. Among the materials, a silicone resin is preferable. 
     The needle-like recessed portion  310  has an inverted shape of the needle-like protruding portion  112  of the microneedle array  100 . The needle-like recessed portion  310  includes a distal end recessed portion  314  corresponding to the needle portion  114  and a cup portion  316  corresponding to the frustum portion  116 . The flat surface  330  has a flat shape corresponding to the sheet portion  102  of the microneedle array  100 . 
     The connecting portion between the flat surface  330  of the first surface  300 A and the cup portion  316  is preferably chamfered (not illustrated). The radius of curvature of the chamfer is preferably 30 μm or more and 300 μm or less. As a result, it is possible to prevent the drug solution that has landed on the needle-like recessed portion  310  from adhering to an edge portion and entering a state of not moving. The drug solution can be easily collected or caused to flow into the center of the needle-like recessed portion  310 , and thus fill the distal end of the needle-like recessed portion  310 . The connecting portion is an example of the edge of the opening of the needle-like recessed portion  310 . 
     The distal end recessed portion  314  has a tapered shape in a depth direction of the mold  300 . The distal end recessed portion  314  can have a diameter of 150 μm or more and 500 μm or less and a height of 150 μm or more and 2000 μm or less. The cup portion  316  is provided with an opening in the first surface  300 A of the mold  300 , has a shape that narrows in the depth direction of the mold  300 , and is connected to the distal end recessed portion  314  at the narrowest portion. The cup portion  316  can have a diameter of 600 μm or more and 1200 μm or less and a height of 100 μm or more and 500 μm or less. 
     The shape of the needle-like recessed portion  310  is not limited to this example. For example, any shape of a cone, a quadrangular pyramid, and a polygonal pyramid without the cup portion  316  can be applied. Moreover, a rocket shape provided with an intermediate recessed portion having a constant width in the depth direction, such as a cylinder, a quadrangular prism, or a polygonal column, between the distal end recessed portion  314  and the cup portion  316  may be applied. In addition, a through-hole that reaches the second surface  300 B of the mold  300  and penetrates the mold  300  can be formed at the distal end of the distal end recessed portion  314 . The arrangement, pitch, number, and the like of the needle-like recessed portions  310  are determined based on the arrangement, pitch, number, and the like of the needle-like protruding portions  112  necessary for the microneedle array  100 . 
     The mold  300  can be produced using a plate precursor (not illustrated) that is a duplicate of the microneedle array  100 . The plate precursor is produced by machining a metal substrate using a cutting tool such as a diamond tool. As the metal substrate, stainless steel, an aluminum alloy, Ni, or the like can be used. 
     The mold  300  in which the plurality of needle-like recessed portions  310  are formed can be produced by adding a silicone resin before being cured dropwise onto a prepared plate precursor, thereafter curing the silicone resin, and peeling the cured silicone resin from the plate precursor. The mold  300  made of the silicone resin may have gas permeability. 
       FIG. 5  is a flowchart showing each step of the manufacturing method of the microneedle array. The manufacturing method of the microneedle array  100  includes a drug solution filling step (step S 1 ) of filling the needle-like recessed portion  310  of the mold  300  with the drug solution, a drug solution drying step (step S 2 ) of drying the filled drug solution, a base material solution filling step (step S 3 ) of filling the needle-like recessed portion  310  with a base material solution, a base material solution drying step (step S 4 ) of drying the filled base material solution, and a releasing step (step S 5 ) of releasing the formed microneedle array  100  from the mold  300 . 
     Drug Solution Filling Step (Step S 1 ) 
     In the drug solution filling step, a liquid droplet of the drug solution is ejected from a nozzle  36  (see  FIG. 6 ) of an ejection head  34  that ejects the drug solution toward the needle-like recessed portion  310  of the mold  300 , and the mold  300  is suctioned by a suction pump  22  (see  FIG. 6 ). Details of the drug solution filling step will be described later. The drug solution is made of, for example, a solution containing the first material M 1  and the drug. 
     Drug Solution Drying Step (Step S 2 ) 
     In the drug solution drying step, for example, drying is performed by blowing air to the drug solution filling the needle-like recessed portion  310 . The environment around the mold  300  may be reduced in pressure. However, the drying method is not particularly limited. 
     Base Material Solution Filling Step (Step S 3 ) 
     In the base material solution filling step, the needle-like recessed portion  310  is filled with the base material solution. The base material solution is made of a solution containing the second material M 2 . The second material M 2  does not contain the drug. 
     Examples of a method of filling the needle-like recessed portion  310  with the base material solution include a filling method using a spin coater. The filling method is not particularly limited, and the base material solution is filled by a dispenser or the like. 
     Base Material Solution Drying Step (Step S 4 ) 
     In the base material solution drying step, as in the drug solution drying step, drying is performed by blowing air to the base material solution filling the needle-like recessed portion  310 . However, the drying method is not particularly limited. 
     Releasing Step (Step S 5 ) 
     In the releasing step, the microneedle array  100  is released from the mold  300  by drying the drug solution and the base material solution. 
     Drug Solution Filling Apparatus 
       FIG. 6  is a schematic configuration diagram of a drug solution filling apparatus  1  (an example of a manufacturing apparatus for a microneedle array) used in the drug solution filling step. The drug solution filling apparatus  1  includes an XYZ stage  10 , an adsorption plate  20 , the suction pump  22 , a camera  30 , the ejection head  34  that ejects the drug solution, and the like. 
     The XYZ stage  10  (an example of a positioning unit) has a placement surface  10 A parallel to an XY plane. The XYZ stage  10  is provided so as to be movable by a motor (not illustrated) in an X direction and a Y direction orthogonal to the X direction, which are two directions parallel to the XY plane. The XYZ stage  10  is provided so as to be movable in a Z direction orthogonal to the XY plane. Furthermore, the XYZ stage  10  is provided so as to be movable in an RθZ direction, which is a rotation direction with the direction parallel to the Z direction as the rotation axis. 
     The XYZ stage  10  can apply vibration to the mold  300 . Examples of the vibration include (1) a horizontal reciprocating motion parallel to the XY plane, (2) a horizontal circular motion parallel to the XY plane, (3) a vertical reciprocating motion parallel to the Z direction, (4) a combination of the horizontal reciprocating motion and the vertical reciprocating motion, and (5) a combination of the horizontal circular motion and the vertical reciprocating motion. 
     The adsorption plate  20  is fixed to the placement surface  10 A of the XYZ stage  10 . The adsorption plate  20  has a placement surface  20 A parallel to the XY plane. The placement surface  20 A is provided with a plurality of adsorption holes (not illustrated). The adsorption plate  20  may be made of a porous member. 
     The suction pump  22  is connected to the adsorption plate  20  via a suction pipe  24 . By driving the suction pump  22 , air can be suctioned from the plurality of adsorption holes (not illustrated) of the placement surface  20 A of the adsorption plate  20 . 
     A conveyance holding device  150  is placed on the placement surface  20 A of the adsorption plate  20 . In the conveyance holding device  150 , the mold  300  is mounted on a placement surface  150 A. Accordingly, the mold  300  can move in each direction as the XYZ stage  10  moves in the X direction, the Y direction, the Z direction, and the RθZ direction. 
     A plurality of adsorption holes  152  pass through the placement surface  150 A of the conveyance holding device  150 . By driving the suction pump  22 , the second surface  300 B (not illustrated) of the mold  300  is suctioned via the plurality of adsorption holes (not illustrated) of the placement surface  20 A of the adsorption plate  20  and the plurality of adsorption holes  152  of the conveyance holding device  150 . 
     The camera  30  comprises, in addition to an imaging lens  32 , an imaging element (not illustrated), an analog-to-digital converter, and an image processing circuit. 
     The imaging lens  32  is a lens group comprising a zoom lens, a focus lens, and the like, and causes incidence ray from a subject to be incident onto the imaging element. 
     The imaging element is a charge coupled device (CCD) type imaging element or a complementary metal oxide semiconductor (CMOS) type imaging element in which a large number of light-receiving elements are two-dimensionally arranged on an imaging surface (not illustrated). The imaging element is disposed in a rear stage of an optical path of the incidence ray of the imaging lens  32 . 
     The imaging lens  32  forms an image of the incidence ray on an imaging surface of the imaging element. The imaging element outputs an analog imaging signal corresponding to the amount of received light. This imaging signal is converted into a digital signal by the analog-to-digital converter, and then generated into an image signal by the image processing circuit. 
     The camera  30  is disposed above the XYZ stage  10  in the Z direction, and the imaging lens  32  is directed downward in the Z direction. Accordingly, the camera  30  can image the mold  300  placed on the XYZ stage  10 . 
     The ejection head  34  is disposed at a position above the XYZ stage  10  in the Z direction and separated from the camera  30  by a distance d on the XY plane including a distance d 1  in the X direction and a distance d 2  in the Y direction. The ejection head  34  includes the nozzle  36  (an example of a drug solution ejection nozzle) that ejects liquid droplets of the drug solution in the first direction. Here, the nozzle  36  is directed downward in the Z direction, and the first direction is a downward direction in the Z direction. The ejection head  34  illustrated in  FIG. 6  includes one nozzle  36 , but may include a plurality of nozzles  36 . 
     As the ejection head  34 , for example, an ink jet head such as a solenoid type ink jet head or a piezoelectric ink jet head can be used. The amount of one liquid droplet ejected from the nozzle  36  is preferably 1 nL to 150 nL, and more preferably 45 nL to 80 nL. 
     In a case where a required amount of the drug solution is ejected from the nozzle  36  into the needle-like recessed portion  310 , one liquid droplet or a plurality of liquid droplets can be ejected. There is no limitation on the number of liquid droplets to be ejected as long as a required amount of the drug solution can be filled. In the case of ejecting a plurality of liquid droplets, as the number of ejected liquid droplets increases, the liquid droplet amount of one liquid droplet decreases. 
     The drug solution ejected from the nozzle  36  flies downward in the Z direction and lands on an object (in this case, the mold  300 ). Therefore, the position of the nozzle  36  on the XY plane and the position on the XY plane where the drug solution lands are the same. 
     The drug solution contains a drug stock solution, a sugar, an additive, and the like as the drug. Moreover, the drug solution contains water, ethanol, or the like as a solvent. 
       FIG. 7  is a block diagram illustrating an electrical configuration of the drug solution filling apparatus  1 . The drug solution filling apparatus  1  includes an imaging controller  40 , a movement controller  42 , an image detector  44 , an ejection controller  46 , a suction controller  48 , and the like. 
     The imaging controller  40  causes the camera  30  to capture an image. 
     The movement controller  42  controls a relative movement between the mold  300  placed on the XYZ stage  10  and the ejection head  34 . Here, the mold  300  is moved by driving the XYZ stage  10 , but the ejection head  34  may be moved, or both the mold  300  and the ejection head  34  may be moved. 
     The movement controller  42  applies vibration selected from (1) the horizontal reciprocating motion parallel to the XY plane, (2) the horizontal circular motion parallel to the XY plane, (3) the vertical reciprocating motion parallel to the Z direction, (4) the combination of the horizontal reciprocating motion and the vertical reciprocating motion, and (5) the combination of the horizontal circular motion and the vertical reciprocating motion, to the mold  300  placed on the XYZ stage  10 . 
     The image detector  44  detects the position of the mold  300  based on the image of the mold  300  captured by the camera  30 . In the present embodiment, the position of the needle-like recessed portion  310  is detected by recognizing the needle-like recessed portion  310  from the image of the mold  300 . 
     The ejection controller  46  controls the timing of ejecting the drug solution from the nozzle  36 , and the liquid droplet amount of the drug solution to be ejected, by controlling the ejection head  34 . 
     The suction controller  48  controls the presence or absence of suction by the suction pump  22 . 
     Drug Solution Filling Step 
       FIG. 8  is a flowchart showing each step included in the drug solution filling step. The drug solution filling step includes a positioning adjustment step (step S 11 ), a relative movement step (step S 12 ), a drug solution ejection step (step S 13 ), an ejection finish determination step (step S 14 ), a vibration step (step S 15 ), an acceptance determination step (step S 16 ), and a suction step (step S 17 ). 
     Positioning Adjustment Step (Step S 11 ) 
     In the positioning adjustment step, the positioning is adjusted so that the position of the needle-like recessed portion  310  of the mold  300  placed on the XYZ stage  10  and the position of the nozzle  36  of the ejection head  34  coincide with each other. The position of the needle-like recessed portion  310  and the position of the nozzle  36  may coincide with each other so that the drug solution ejected from the nozzle  36  toward the needle-like recessed portion  310  lands on the needle-like recessed portion  310 , and the positions of the two do not need to strictly coincide with each other. Here, the needle-like recessed portion  310  and the nozzle  36  are virtually positioned by detecting the position of the needle-like recessed portion  310  from the captured image. 
     First, the conveyance holding device  150  on which the mold  300  is mounted is placed on the placement surface  20 A of the adsorption plate  20 . 
     The movement controller  42  controls the XYZ stage  10  to move the mold  300  within the angle of view of the captured image of the camera  30 . The imaging controller  40  controls the camera  30  to capture an image of the mold  300  (an example of an imaging step). The image detector  44  calculates the position of each needle-like recessed portion  310  by analyzing the image of the mold  300  captured by the camera  30 . 
     For example, the needle-like recessed portion  310  of the mold  300  is moved to the center within the angle of view of the captured image of the camera  30  by the XYZ stage  10 , and the XY plane coordinates (X,Y) of the XYZ stage  10  at this point are detected. By performing this for all the needle-like recessed portions  310 , the positions of all the needle-like recessed portions  310  can be detected. 
     In the image of the mold  300  captured by the camera  30 , the flat surface  330  has a relatively bright brightness, and the needle-like recessed portion  310  has a relatively dark brightness. By using this contrast, the needle-like recessed portion  310  can be moved to the center within the angle of view of the captured image of the camera  30 . 
     Instead of moving all the needle-like recessed portions  310  to the center within the angle of view of the image captured by the camera  30 , only the XY plane coordinates (X,Y) of three to five needle-like recessed portions  310  may be detected and the direction (rotation) of the mold  300  in the XY plane from the coordinates and the deviation or expansion and contraction of the mold  300  in the XY plane may be analyzed to detect the positions of the other needle-like recessed portions  310 . 
     Alternatively, the mold  300  may be provided with a plurality of alignment marks, and the XY plane coordinates (X,Y) of the needle-like recessed portion  310  may be detected by reading the alignment marks. 
     As described above, by detecting the position of the needle-like recessed portion  310  based on the XY plane coordinates (X,Y) of the XYZ stage  10 , the needle-like recessed portion  310  and the nozzle  36  are virtually positioned. Mechanical positioning may be performed by a positioning adjustment holding device or the like. 
     Furthermore, the position (height) of the mold  300  in the Z direction may be adjusted by measuring the distance between the needle-like recessed portion  310  or the alignment mark and the camera  30 . The distance between the nozzle  36  and the mold  300  is preferably adjusted to be 0.5 mm to 5 mm, and preferably 1 mm to 2 mm. 
     Relative Movement Step (Step S 12 ) 
     The movement controller  42  controls the XYZ stage  10  based on the detection result of the image detector  44  to move the mold  300  in the X direction and the Y direction so as to cause the position of the nozzle  36  of the ejection head  34  on the XY plane and the position of the needle-like recessed portion  310  on the XY plane to coincide with each other. That is, the position of the nozzle  36  and the position of the needle-like recessed portion  310  are caused to coincide with each other in a plan view in the direction (Z direction) parallel to the ejection direction of the drug solution from the nozzle  36 . 
     Coordinates (X+d 1 ,Y+d 2 ) obtained by adding the distance d 1  in the X direction between the camera  30  and the nozzle  36  of the ejection head  34  and the distance d 2  in the Y direction to the coordinates (X,Y) of the needle-like recessed portion  310  calculated in step S 11  are the coordinates of the nozzle  36 . As illustrated in  FIG. 9 , the movement controller  42  moves the XYZ stage  10  to the coordinates. 
     Drug Solution Ejection Step (Step S 13 ) 
     As illustrated in  FIG. 10 , the ejection controller  46  controls the ejection head  34  to eject a drug solution ML 1  from the nozzle  36 . As illustrated in  FIG. 11 , the ejected drug solution ML 1  lands on the needle-like recessed portion  310 . Here, one droplet of the drug solution ML 1  is ejected from the nozzle  36  to one needle-like recessed portion  310  and is caused to land on the needle-like recessed portion  310 . A plurality of droplets of the drug solution ML 1  may be caused to land on one needle-like recessed portion  310 . 
     Ejection Finish Determination Step (Step S 14 ) 
     The ejection controller  46  determines whether or not the drug solution ML 1  has been ejected to land on all the needle-like recessed portions  310  of the mold  300 . Here, the number of ejections of the drug solution ejected in the drug solution ejection step and the number of needle-like recessed portions  310  whose positions have been detected in the positioning adjustment step are compared to each other for determination. 
     In a case where it is determined that there is a needle-like recessed portion  310  on which the drug solution ML 1  does not land, the process returns to step S 12  and the same processing is performed. That is, the position on the XY plane of the needle-like recessed portion  310  to which the drug solution ML 1  has not been ejected and the position on the XY plane of the nozzle  36  are caused to coincide with each other (step S 12 ), and the drug solution is ejected from the nozzle  36  to land on the needle-like recessed portion  310  (step S 13 ). The ejection order of the drug solution to the needle-like recessed portions  310  is not particularly limited, but from the viewpoint of shortening the total movement distance of the XYZ stage  10 , it is preferable to eject the drug solution sequentially in order from the needle-like recessed portion  310  disposed at the end of the mold  300  to adjacent needle-like recessed portions  310 . 
     In a case where it is determined that the drug solution ML 1  has landed on all the needle-like recessed portions  310 , the process proceeds to step S 15 . 
     Vibration Step (Step S 15 ) 
       FIG. 12  illustrates the mold  300  having finished the ejection of the drug solution ML 1  to the needle-like recessed portion  310 . The drug solution ML 1  ejected in the drug solution ejection step needs to close the needle-like recessed portion  310 , that is, be into contact with the entire circumference of the wall portion of the needle-like recessed portion  310 . In a case where the landed drug solution ML 1  does not close the needle-like recessed portion  310 , the drug solution ML 1  landed in the suction step cannot fill the distal end of the tapered shape of the distal end recessed portion  314 . 
     Therefore, when the position of the nozzle  36  and the position of the needle-like recessed portion  310  are caused to coincide with each other in the relative movement step, precise positional accuracy is required. For this reason, it is necessary to precisely adjust the positioning in the positioning adjustment step. 
     However, in  FIG. 12 , a plurality of the drug solutions ML 1  do not close the needle-like recessed portions  310 . Even in a case where the positioning is precisely adjusted, a positional deviation is caused by a landing positional deviation due to apparatus vibration that occurs when the XYZ stage  10  or the nozzle  36  is moved at a high velocity, a landing positional deviation due to a change in liquid droplet flight velocity caused by a state change in the nozzle  36  over time and a change in the drug solution ML 1  over time, a positional deviation during the installation of the mold  300 , a positioning deviation of the needle-like recessed portions  310  due to expansion and contraction or strain of the mold  300  itself, and combinations thereof. It is difficult to completely eliminate the positional deviation. 
     Therefore, in the present embodiment, as illustrated in  FIGS. 8 and 13 , after the ejection is finished, the mold  300  is vibrated to move the drug solution ML 1  toward the needle-like recessed portion  310 , whereby the needle-like recessed portion  310  is closed with the drug solution ML 1 . As illustrated in  FIG. 13 , the vibration is the horizontal reciprocating motion parallel to the XY plane. 
     The horizontal reciprocating motion is preferably performed, for example, with an amplitude of 1 mm or more and 10 mm or less, a frequency of 15 Hz or higher and 100 Hz or lower, and a time of 1 second or longer and 180 seconds or shorter. The horizontal reciprocating motion within the ranges of amplitude, frequency, and time can move the drug solution ML 1  and close the needle-like recessed portion  310  with the drug solution ML 1 . The amplitude is more preferably 3 mm or more and 8 mm or less, the frequency is more preferably 40 Hz or higher and 70 Hz or lower, and the time is more preferably 50 seconds or longer and 80 seconds or shorter. 
     The vibration is not limited to the horizontal reciprocating motion illustrated in  FIG. 13 . For example, as illustrated in  FIG. 14 , the vibration is the horizontal circular motion parallel to the XY plane. The horizontal circular motion is preferably performed, for example, with an amplitude of 1 mm or more and 10 mm or less, a frequency of 15 Hz or higher and 100 Hz or lower, and a time of 1 second or longer and 180 seconds or shorter. The horizontal circular motion within the ranges of amplitude, frequency, and time can move the drug solution ML 1  and close the needle-like recessed portion  310  with the drug solution ML 1 . The amplitude is more preferably 3 mm or more and 8 mm or less, the frequency is more preferably 40 Hz or higher and 70 Hz or lower, and the time is more preferably 50 seconds or longer and 80 seconds or shorter. 
     The horizontal circular motion can be realized, for example, by circularly moving the mold  300  around a rotation axis (parallel to the Z direction) that is eccentric from the center axis (parallel to the Z direction) of the mold  300 . The circular motion may be a true circular locus or an elliptical locus. 
     The vibration is, for example, as illustrated in  FIG. 15 , the vertical reciprocating motion parallel to the Z direction. The vertical reciprocating motion is preferably performed, for example, with an amplitude of 1 mm or more and 10 mm or less, a frequency of 15 Hz or higher and 100 Hz or lower, and a time of 1 second or longer and 180 seconds or shorter. The vertical reciprocating motion within the ranges of amplitude, frequency, and time can move the drug solution ML 1  and close the needle-like recessed portion  310  with the drug solution ML 1 . The amplitude is more preferably 3 mm or more and 8 mm or less, the frequency is more preferably 40 Hz or higher and 70 Hz or lower, and the time is more preferably 50 seconds or longer and 80 seconds or shorter. 
     The vibration is, for example, as illustrated in  FIG. 16 , the combination of the horizontal reciprocating motion and the vertical reciprocating motion. Each of the horizontal reciprocating motion and the vertical reciprocating motion is preferably performed, for example, with an amplitude of 1 mm or more and 10 mm or less, a frequency of 15 Hz or higher and 100 Hz or lower, and a time of 1 second or longer and 180 seconds or shorter. Each of the horizontal reciprocating motion and the vertical reciprocating motion within the ranges of amplitude, frequency, and time can move the drug solution ML 1  and close the needle-like recessed portion  310  with the drug solution ML 1 . The amplitude is more preferably 3 mm or more and 8 mm or less, the frequency is more preferably 40 Hz or higher and 70 Hz or lower, and the time is more preferably 50 seconds or longer and 80 seconds or shorter. 
     Furthermore, for example, as illustrated in  FIG. 17 , the vibration is the combination of the horizontal circular motion and the vertical reciprocating motion. Each of the horizontal circular motion and the vertical reciprocating motion is preferably performed, for example, with an amplitude of 1 mm or more and 10 mm or less, a frequency of 15 Hz or higher and 100 Hz or lower, and a time of 1 second or longer and 180 seconds or shorter. Each of the horizontal circular motion and the vertical reciprocating motion within the ranges of amplitude, frequency, and time can move the drug solution ML 1  and close the needle-like recessed portion  310  with the drug solution ML 1 . The amplitude is more preferably 3 mm or more and 8 mm or less, the frequency is more preferably 40 Hz or higher and 70 Hz or lower, and the time is more preferably 50 seconds or longer and 80 seconds or shorter. 
     Acceptance Determination Step (Step S 16 ) 
     In the acceptance determination step, after finishing the vibration step, the imaging controller  40  and the camera  30  image all the needle-like recessed portions  310  of the mold  300 , and check whether or not the number of the needle-like recessed portions  310  whose openings are closed by the drug solution is equal to or more than a predetermined reference number. This reference number is determined by the minimum number of needle-like protruding portions  112  required in one microneedle array  100 . 
     In a case where the number of closed needle-like recessed portions  310  is less than the reference number, the process of this flowchart is finished as a rejected product. In a case where the number of closed needle-like recessed portions  310  is equal to or more than the reference number, the process proceeds to step S 17  as an acceptable product. 
     Suction Step (Step S 17 ) 
     The suction controller  48  drives the suction pump  22  to suction the second surface  300 B of the mold  300 . By this suction, as illustrated in  FIG. 18 , the drug solution ML 1  that has landed on the needle-like recessed portion  310  fills the distal end of the tapered shape of the distal end recessed portion  314 . 
     As above, the drug solution filling step is finished. In the embodiment, the case where the drug solution ejection step, the vibration step, and the suction step are performed with the same XYZ stage  10  has been described. However, the embodiment is not limited to this form. The drug solution ejection step, the vibration step, and the suction step can be performed with separate stages. 
     For example, when the drug solution ejection step is finished, the conveyance holding device  150  on which the mold  300  is mounted is moved to a vibration stage that performs the vibration step, and the mold  300  is vibrated by the vibration stage. Next, when the vibration step is finished, the conveyance holding device  150  on which the mold  300  is mounted is moved to a suction stage that performs the suction step, and the second surface  300 B of the mold  300  is suctioned by the suction stage. The acceptance determination step can be performed by either the vibration stage or the suction stage. 
     Here, the distance d 1  and the distance d 2  are treated as known values, but in a case where the distances are unknown, the distances can be obtained as follows. 
     A dummy mold that is not provided with the needle-like recessed portions  310  is mounted on the conveyance holding device  150  and placed on the placement surface  20 A of the adsorption plate  20 . The drug solution is ejected from the nozzle  36  to the dummy mold so as to land on the dummy mold. 
     Next, the XYZ stage  10  is moved in the X direction and the Y direction so that the landed drug solution is disposed at the center of the angle of view of the captured image of the camera  30 . Here, the amount of movement of the XYZ stage  10  in the X direction is the distance d 1 , and the amount of movement thereof in the Y direction is the distance d 2 . 
     Next, a preferable form in the vibration step (step S 15 ) will be described. For example, in a case where the vibration is the horizontal reciprocating motion, as illustrated in  FIG. 19 , it is preferable that the movement direction (arrow A) of the drug solution ML 1  and the direction of the horizontal reciprocating motion (arrow B) are the same direction. The same direction may be achieved when the movement direction of the drug solution ML 1  and the direction of the horizontal reciprocating motion are parallel or substantially parallel in a plan view of the mold  300 . By causing the movement direction of the drug solution ML 1  and the direction of the horizontal reciprocating motion to be the same direction, the drug solution ML 1  can be moved to the needle-like recessed portion  310  more reliably within a short period of time. 
     As the movement direction of the drug solution ML 1 , for example, a direction that is easily deviated can be obtained in advance from the characteristics of the apparatus or the like. The movement direction of the drug solution ML 1  is obtained by, for example, imaging the needle-like recessed portion  310  that is not closed by the drug solution ML 1  and the drug solution ML 1  that is not closing the needle-like recessed portion  310  by the imaging device, and analyzing the captured image. The vibration of the horizontal reciprocating motion in the same direction as the obtained movement direction of the drug solution ML 1  is applied to the mold  300 . 
     The vibration is not particularly limited as long as the vibration can be defined by the maximum amplitude, frequency, and time.  FIGS. 20 to 22  are waveform diagrams in which the vertical axis represents amplitude and the horizontal axis represents time.  FIG. 19  shows a sine wave,  FIG. 21  shows a triangle wave, and  FIG. 22  shows a pulse wave. However, the vibration is not limited to the waveform diagrams shown in  FIGS. 20 to 22 . 
     EXAMPLES 
     The present invention will be specifically described by the following examples, but the present invention is not limited to these examples. 
     First, a mold  300  in which 100 needle-like recessed portions  310  were formed was prepared.  FIG. 23  is a cross-sectional view for describing the shape of the needle-like recessed portion  310  according to the example, and is a further enlarged view of  FIG. 3 . As illustrated in  FIG. 23 , the diameter of a distal end recessed portion  314  is 300 μm. In addition, a height (depth) H 1  was set to 720 μm, and an opening diameter (opening diameter of the needle-like recessed portion  310 ) D of a cup portion  316  was set to 600 μm. An angle θ of an inner portion of the mold  300 , which is the angle formed between a flat surface  330  of the mold  300  and the inside of the cup portion  316 , was set to 45°. The height (depth) H 2  of the cup portion  316  was 150 μm from the opening diameter D and the angle θ. 
     Furthermore, the connecting portion between the flat surface  330  of the first surface  300 A and the cup portion  316  was chamfered, and the radius of curvature R 1  of the chamfered arc was set to 50 μm. Due to the chamfering, the angle θ was an angle formed by an extension line of the flat surface  330  of the first surface  300 A and an extension line of the cup portion  316 . 
     Moreover, the connecting portion between the cup portion  316  and the distal end recessed portion  314  was chamfered, and the radius of curvature R 2  of the chamfered arc was set to 50 μm. 
     The ejection amount of a drug solution ejected from the nozzle  36  was 35 nL, and the drop velocity was 0.3 m/s. At each level with the kind of vibration, amplitude, frequency, and time as parameters, whether or not the needle-like recessed portion  310  could be closed and filled with the drug solution was evaluated.  FIG. 24  is a table showing the parameters at each level and the evaluation results. As shown in  FIG. 24 , Levels  1  to  41  were evaluated. 
     Determination Standard 
     A case where the ejected drug solution closed and filled all the 100 needle-like recessed portions  310  formed in the mold  300  was regarded as a non-defective product, and a case where one or more needle-like recessed portions  310  could not be closed and filled was regarded as a defective product. 100 molds  300  were prepared, and the drug solution was ejected to the 100 molds  300 . A case of a non-defective product yield of 95% or more was determined as P, and a case of a non-defective product yield of less than 95% was determined as F. 
     In Level  1 , since no vibration was applied to the mold  300 , a determination result of “F” was obtained. 
     In Levels  2  to  9 , vibration of a horizontal reciprocating motion was applied to the mold  300 , and the amplitude, frequency, and time were changed. In each of Levels  2  to  9 , a determination result of “P” was obtained. 
     In Levels  10  to  17 , vibration of a horizontal circular motion was applied to the mold  300 , and the amplitude, frequency, and time were changed. In each of Levels  10  to  17 , a determination result of “P” was obtained. 
     In Levels  18  to  25 , vibration of a vertical reciprocating motion was applied to the mold  300 , and the amplitude, frequency, and time were changed. In each of Levels  18  to  25 , a determination result of “P” was obtained. 
     In Levels  26  to  33 , vibration of a combination of the horizontal reciprocating motion and the vertical reciprocating motion was applied to the mold  300 , and the amplitude, frequency, and time were changed. In each of Levels  26  to  33 , a determination result of “P” was obtained. 
     In Levels  34  to  41 , vibration of a combination of the horizontal circular motion and the vertical reciprocating motion was applied to the mold  300 , and the amplitude, frequency, and time were changed. In each of Levels  34  to  41 , a determination result of “P” was obtained. 
     From the table in  FIG. 24 , it can be understood that the step of applying vibration to the mold  300  is useful for closing and filling the needle-like recessed portions  310  when the drug solution is ejected onto the mold  300 . 
     Others 
     The technical scope of the present invention is not limited to the scope described in the above embodiment. The configurations and the like in the embodiments can be appropriately combined between the embodiments without departing from the gist of the present invention. 
     EXPLANATION OF REFERENCES 
     
         
         
           
               1 : drug solution filling apparatus 
               10 : XYZ stage 
               10 A: placement surface 
               20 : adsorption plate 
               20 A: placement surface 
               22 : suction pump 
               24 : suction pipe 
               30 : camera 
               32 : imaging lens 
               34 : ejection head 
               36 : nozzle 
               40 : imaging controller 
               42 : movement controller 
               44 : image detector 
               46 : ejection controller 
               48 : suction controller 
               100 : microneedle array 
               102 : sheet portion 
               102 A: first surface 
               102 B: second surface 
               110 : array pattern 
               112 : needle-like protruding portion 
               114 : needle portion 
               116 : frustum portion 
               150 : conveyance holding device 
               150 A: placement surface 
               152 : adsorption hole 
               300 : mold 
               300 A: first surface 
               300 B: second surface 
               310 : needle-like recessed portion 
               312 : recessed portion pattern 
               314 : distal end recessed portion 
               316 : cup portion 
               320 : weir 
               330 : flat surface 
             A, B: arrow 
             d: distance 
             D: opening diameter 
             d 1 : distance 
             d 2 : distance 
             M 1 : first material 
             M 2 : second material 
             ML 1 : drug solution 
             R 1 , R 2 : radius of curvature 
             S 1 , S 2 , S 3 , S 4 , S 5 , S 11 , S 12 , S 13 , S 14 , S 15 , S 16 , S 17 : step