Microneedle patch, method for manufacturing same, and apparatus for manufacturing microneedle array

Abstract

A microneedle patch with which a treatment is reliably completed in a short time when a microneedle is administered into skin or mucous membrane is provided. A microneedle patch ( 100 F) includes a base member ( 101 ) and a plurality of microneedles ( 103 g ) supported by the base member ( 101 ). Each microneedle ( 103 g ) includes a top-section layer ( 104 ) comprising a biologically active substance to be inserted in dermis ( 310 ), and an intermediate layer ( 106 ) provided between the top-section layer ( 104 ) and the base member ( 101 ), having a composition having breaking strength weaker than breaking strength of a composition of the top-section layer ( 104 ), and having a thickness of 5 μm and 100 μm inclusive.

1 . A microneedle patch produced by a droplet discharging apparatus configured to be capable of separately discharging, as raw material liquid, for example, first liquid, second liquid, third liquid, and fourth liquid containing components different from each other, wherein
 an intermediate layer is formed after discharge, drying, and hardening of the top-section layer comprising a biologically active substance, wherein the intermediate layer has a breaking property higher than a breaking property of a top-section layer, has a function to prevent backflow of, through a penetrating hole, drug released in dermis, and has a thickness of 5 μm to 100 μm, and   the intermediate layer is configured to break in the dermis in 5 seconds to 20 seconds approximately.   
     
     
         2 . The microneedle patch according to  claim 1 , produced by discharging raw material liquid from a droplet discharging apparatus, wherein the strength of a microneedle is highest in a bottom-section layer, followed in order by a top section comprising drug, and an intermediate layer set as a layer having a lowest strength. 
     
     
         3 . The microneedle patch according to  claim 1 , produced by discharging raw material liquid from a droplet discharging apparatus, wherein a weight-average molecular weight of a microneedle is largest in a top section comprising a biologically active substance, followed in order by a bottom-section layer, and an intermediate layer set as a layer having a lowest weight-average molecular weight. 
     
     
         4 . The microneedle patch according to  claim 1 , which is produced by discharging different kinds of raw material liquid from a droplet discharging apparatus, wherein the intermediate layer consists of two or more layers. 
     
     
         5 . The microneedle patch according to  claim 4 , produced by discharging different kinds of raw material liquid from a droplet discharging apparatus, and including two or more intermediate layers, wherein
 a first intermediate layer is formed of a polymer material having a high hardness and a low absorbability and selected as a raw material selected to have high concentration,   a dissolution time of the first intermediate layer is controlled to be 10 minutes to 24 hours, and   drug contained in a top section and released in dermis is prevented from flowing back in a direction toward epidermis through a penetrating hole.   
     
     
         6 . The microneedle patch according to  claim 5 , produced by discharging different kinds of raw material liquid from a droplet discharging apparatus, and including two or more intermediate layers, wherein
 a second intermediate layer is formed of a polymer material having a low hardness and a high absorbability and selected as a raw material selected to have low concentration, and   a function to easily break and separate a top section from a bottom-section layer and reliably leave the top section in dermis in a short time is provided.   
     
     
         7 . The microneedle patch according to  claim 1 , produced by discharging raw material liquid from a droplet discharging apparatus, wherein an intermediate layer is inside a bottom-section layer. 
     
     
         8 . The microneedle patch according to  claim 1 , produced by discharging raw material liquid from a droplet discharging apparatus, wherein
 the microneedle patch is formed integrally with a bonding surface or a flat surface adhering to a substrate when part or all of a bottom-section layer is produced, so that   collapse of microneedles due to piercing is prevented, and a top section comprising a biologically active substance easily and reliably breaks from the bottom-section layer, and   a plurality of intermediate layers each having a function to prevent backflow of the biologically active substance from inside of dermis are provided.   
     
     
         9 . The microneedle patch according to  claim 1 , produced by discharging raw material liquid from a droplet discharging apparatus, wherein
 an intermediate layer is provided between a top section and a bottom-section layer, and   the intermediate layer is configured to break in dermis in 5 seconds to 20 seconds approximately in order to leave the top section in the dermis.   
     
     
         10 . A microneedle array manufacturing apparatus for shaping a microneedle array consisting of a plurality of microneedles by filling a plurality of recesses formed in a mold with raw material liquid for forming the microneedles, the apparatus comprising:
 at least one droplet discharging apparatus capable of discharging, to each recess, a droplet of the raw material liquid in a predetermined amount equal to or smaller than the volume of the recess; and   a positioning apparatus capable of adjusting relative position between the droplet discharging apparatus and the mold so as to land the droplet into the recess from the droplet discharging apparatus, wherein   the at least one droplet discharging apparatus are a plurality of droplet discharging apparatuses each capable of discharging raw material obtained by changing, as appropriate, a mixture ratio and concentration of a bioabsorbable formulation that forms a microneedle.   
     
     
         11 . A microneedle patch manufacturing method comprising the processes of:
 forming a top-section layer in a recess of a mold;   discharging, onto the top-section layer in the recess, a plurality of droplets of intermediate-layer raw material liquid from a droplet discharging apparatus;   hardening the intermediate-layer raw material liquid to form an intermediate layer having a breaking strength weaker than a breaking strength of the top-section layer;   discharging, onto the intermediate layer in the recess, a plurality of droplets of bottom-section-layer raw material liquid from the droplet discharging apparatus; and   hardening the bottom-section-layer raw material liquid to form a bottom-section layer having a breaking strength stronger than the breaking strength of the intermediate layer.