Method for manufacturing an intracutaneous microneedle array

• US 6,471,903 B2
• Filed: 09/19/2001
• Issued: 10/29/2002
• Est. Priority Date: 06/09/1999
• Status: Expired due to Term

• Current Assignee: Corium, Inc.
• Original Assignee: The Procter & Gamble Company
• Inventors: Gartstein, Vladimir, Sherman, Faiz Feisal, Owens, Grover David, Yuzhakov, Vadim Vladimirovich
• Primary Examiner(s): Heitbrink, Jill L.
• Application Number:
  US09/956,520
• Publication Number:
  US 20020020688A1
• Time in Patent Office: 405 Days
• Field of Search: 264/328.1, 249/60, 249/64, 425/577
• US Class Current: 264/328.1
• CPC Class Codes: A61M 2037/0023 Drug applicators using microneedles
• CPC Class Codes: A61M 2037/003 having a lumen
• CPC Class Codes: A61M 2037/0053 Methods for producing microneedles
• CPC Class Codes: A61M 37/00 Other apparatus for introducing media into the body for reproduction or fertilisation A61B17/425; apparatus for iontophoresis or cataphoresis A61N1/30; Percutany, i.e. introducing medicines into the body by diffusion through the skin salt baths A61H33/04
• CPC Class Codes: A61M 37/0015 by using microneedles
• CPC Class Codes: B26F 1/24 Perforating by needles or pins
• CPC Class Codes: B29C 2059/023 Microembossing
• CPC Class Codes: B29C 33/0033 constructed for making articles provided with holes
• CPC Class Codes: B29C 33/42 characterised by the shape of the moulding surface, e.g. ribs or grooves
• CPC Class Codes: B29C 37/0053 Moulding articles characterised by the shape of the surface, e.g. ribs, high polish mould construction therefor B29C33/42; surface shaping of articles B29C59/00; by incorporating filler in or near the surface B29C70/64
• CPC Class Codes: B29C 45/2628 with mould parts forming holes in or through the moulded article, e.g. for bearing cages
• CPC Class Codes: B29C 51/00 Shaping by thermoforming , i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor blow moulding of tubular preforms B29C49/00, deforming of tubular or hollow preforms B29C67/0014
• CPC Class Codes: B29C 51/082 by shaping between complementary mould parts
• CPC Class Codes: B29L 2031/7544 Injection needles, syringes
• CPC Class Codes: B29L 2031/756 Microarticles, nanoarticles
• CPC Class Codes: B81B 2201/055 Microneedles
• CPC Class Codes: B81C 1/00111 Tips, pillars, i.e. raised structures microneedles A61M37/0015
• CPC Class Codes: B81C 2201/036 Hot embossing

Abstract

An array of hollow microneedles is constructed of molded plastic, in which a micro-machining technique is used to fabricate the molds used in a plastic microforming process. The molds are detachable and can be re-used. The preferred process for making the plastic arrays of microneedles is a microinjection technique. In the microinjection method, a molten plastic substance is injected between two micro-machined molds that contain microhole and micropillar arrays. Once the desired shape of the microneedle array has been formed, the mold and the plastic material are cooled down. Next, the molds are separated and the plastic microneedle array is detached from the mold structures.

Claims

1. A method of manufacturing a microneedle array, comprising:

(a) providing a top mold structure and bottom mold structure, said top mold structure having a bottommost substantially planar surface, said bottom mold structure having a topmost substantially planar surface, said top mold structure defining a plurality of microholes and a plurality of micropillars that are located within said microholes, said micropillars each extending a substantially equal length which causes said micropillars to extend beyond said bottommost surface, said micropillars being configured so as to prevent said bottommost surface from contacting said topmost surface when said top and bottom mold structures are closed, thereby creating a gap between the bottommost surface of said top mold structure and the topmost surface of said bottom mold structure;

(b) heating, in a separate container, a moldable material to above its melting temperature;

(c) injecting, when said top and bottom mold structures are closed, said moldable material into said gap between the bottom surface of said top mold structure and the top surface of said bottom mold structure;

(d) cooling said mold and said material to a temperature below the melting temperature of said material; and

(e) opening said top and bottom mold structures, and detaching said material from said top and bottom mold structures, thereby leaving a unitary structure of an array of hollow microneedles.

2. The method as recited in claim 1, wherein said material comprises a polymer.

3. The method as recited in claim 1, wherein each of said plurality of micropillars is substantially cylindrical in shape, and each of said plurality of microholes is substantially conical in shape, and said individual micropillars and microholes being concentric.