Microneedle structure and manufacturing method and manufacturing apparatus for the same

Patent metadata

Field	Value
Publication number	US-11648382-B2
Application number	US-201816642464-A
Country	US
Kind code	B2
Filing date	Jul 6, 2018
Priority date	Aug 30, 2017
Publication date	May 16, 2023
Grant date	May 16, 2023

Abstract

A microneedle structure, a manufacturing method therefor, and a manufacturing apparatus therefor are presented. The microneedle structure manufacturing method according to one embodiment of the present invention comprises the steps of: a) injecting, into a lower mold comprising a microneedle intaglio, a polymer solution containing a biocompatible polymer; and b) coupling a shape control mold, which comprises a protrusion, to the lower mold such that one end of the protrusion of the shape control mold is impregnated with the biocompatible polymer solution injected into the microneedle intaglio.

First claim

The invention claimed is:

1. A microneedle structure manufacturing method comprising:
a) injecting a polymer solution containing a biocompatible polymer into a lower mold that includes a microneedle intaglio;
b) coupling a shape control mold to the lower mold to impregnate one end of a protrusion included in the shape control mold into the biocompatible polymer solution injected into the microneedle intaglio; and
c) curing the polymer solution and removing a mold that includes the lower mold and the shape control mold,
wherein
the a) comprises:
a1) combining an upper mold including through-holes to be spaced apart from an upper portion of the lower mold, while disposing a penetration-type pore apart from an upper portion of the microneedle intaglio; and
a2) injecting the polymer solution to fill at least a part of a separation space between the upper mold and the lower mold while filling the microneedle intaglio, and
in the b), one end of the protrusion is impregnated into the biocompatible polymer solution filled in the microneedle intaglio through the penetration-type pore.

2. The microneedle structure manufacturing method of claim 1 , wherein, in the b), the shape control mold is coupled to the lower mold to satisfy Equation 1:
0.1 L 0 ≤P wiretip ≤0.9 L 0 ,  (Equation 1)

wherein L 0 denotes a length of the microneedle intaglio, and P wiretip denotes a position of one end of the protrusion when a lowest point of the microneedle intaglio is zeroed.

3. The microneedle structure manufacturing method of claim 2 , wherein the a2) comprises:
a2-1) injecting a first polymer solution that contains a first biocompatible polymer and a drug into the microneedle intaglio, while locating a liquid level of the first polymer solution in a lower portion of the P wiretip ; and
a2-2) injecting a second polymer solution that contains a second biocompatible polymer to fill a space of the microneedle intaglio above the liquid level of the first polymer solution.

4. The microneedle structure manufacturing method of claim 1 , wherein
the shape control mold further comprises a flat panel, and
in the b), the protrusion is located only in an opening area, which is a flat panel area corresponding to an opening of the microneedle intaglio in the flat panel of the shape control mold, and the protrusion comprises one to twelve wires.

5. The microneedle structure manufacturing method of claim 4 , wherein
when the protrusion comprises one wire, the wire is located at a center of the opening area, and when the protrusion comprises two or more wires, the wires are located to satisfy Equation 2:
θ=360°/ n,   (Equation 2)

wherein θ denotes an angle (°) between two wires neighboring each other with reference to the center of the opening area, and n denotes a natural number from 2 to 12, which is the number of wires.

6. A microneedle structure manufacturing apparatus comprising:
a lower mold that includes a microneedle intaglio;
a shape control mold that includes a protrusion, and is coupled with the lower mold to impregnate one end of the protrusion into the microneedle intaglio; and
an injection portion that injects a polymer solution into the microneedle intaglio of the lower mold,
wherein the shape control mold further comprises a flat panel, and
the protrusion comprises one to twelve wires that are located in an opening area, which is a flat area corresponding to an opening of the microneedle, and when the protrusion includes one wire, the protrusion is located at a center of the opening area, while when the protrusion includes two or more wires, Equation 2 is satisfied:
θ=360°/ n,   (Equation 2)

wherein θ denotes an angle (°) between two wires neighboring each other with reference to the center of the opening area, and n denotes a natural number from 2 to 12, which is the number of wires.

7. The microneedle structure manufacturing apparatus of claim 6 , wherein the protrusion comprises two or more wires, and the two or more wires contact an edge of the opening area or neighboring wires contact each other.

8. The microneedle structure manufacturing apparatus of claim 6 , wherein the protrusion satisfies Equation 3:
0.1 ≤A wire /A 0 ≤0.9,  (Equation 2)

wherein A wire denotes a total area of all wire cross-sections included in a protrusion, and A 0 denotes an area of an opening area.

9. The microneedle structure manufacturing apparatus of claim 6 , further comprising an upper mold where a penetration-type pore is formed,
wherein the upper mold is coupled with the lower mold such that the penetration-type pore is located above an opening of the microneedle intaglio, and
the shape control mold further comprises a spacer that forms an empty space between the flat panel and the upper mold on a side that is the same as one side of the flat plane where the protrusion is located.

10. The microneedle structure manufacturing apparatus of claim 9 , further comprising a separation mold that separates the upper mold and the lower mold while being disposed between the lower mold and the upper mold.

11. The microneedle structure manufacturing apparatus of claim 6 , wherein the lower mold comprises a first lower mold that includes a first intaglio area that corresponds to a tip of the microneedle and a second lower mold that includes a second intaglio area that corresponds to a base portion and a pillar of the microneedle.

12. A microneedle structure comprising:
a base layer, which is a flat layer; and
a microneedle that is formed of a biocompatible polymer material and located on one side of the base layer,
wherein the microneedle comprises a pore that extends in a direction of a tip of the microneedle while penetrating the base layer such that one end of the pore is located inside the microneedle,
wherein the pore is two to twelve wire-shaped pores, and the wire-shaped pores are arranged to surround a central axis of a length direction of the microneedle.

13. The microneedle structure of claim 12 , wherein the wire-shaped pores that are adjacent to each other communicate with each other while being in contact with each other.

14. The microneedle structure of claim 12 , wherein the microneedle further comprises a second pore connecting a surface of the microneedle to at least one of the wire-shaped pores such that the at least one of the wire-shaped pores and an outside of the microneedle communicate with each other.

15. The microneedle structure of claim 12 , wherein the pore satisfies Equation 4:
0.1 L 1 ≤E tip ≤0.9 L 1 ,  (Equation 4)

wherein L 1 denotes a length of the microneedle, and E tip denotes a position of one end of the wire-shaped pore while zeroing the tip of the microneedle, and
wherein the microneedle satisfies Equation 5:
0.1 ≤A empty /A 1 ≤0.9,  (Equation 5)

wherein A empty denotes a total empty space area of cross-sections of all wire-shaped pores included in the microneedle, and A 1 denotes a cross-section of the microneedle,
wherein a first area, which is an area from the tip of the microneedle to below one end of the wire-shaped pore, contains a first biocompatible polymer and a biochemical material, and other areas excluding the first area in the microneedle contain a second biocompatible polymer, and
wherein the first biocompatible polymer contains a biodegradable polymer and the second biocompatible polymer contains a biosoluble polymer.

Assignees

• Korea Inst Mach & Materials

Inventors

• Chang Sunghwan
• Kim Jung Yup
• Kim Jaegu
• Yoo Yeong-Eun

Classifications

• A61M37/0015 Primary

  by using microneedles · CPC title

• A61M2037/0023

  Drug applicators using microneedles · CPC title

• B29C39/026 Primary

  characterised by the shape of the surface · CPC title

• A61M2037/0046

  Solid microneedles · CPC title

• A61M2037/0038

  having a channel at the side surface · CPC title