Method of making microneedles

• US 8,551,391 B2
• Filed: 02/03/2005
• Issued: 10/08/2013
• Est. Priority Date: 02/17/2004
• Status: Active Grant

• Current Assignee: Avery Dennison Corporation
• Original Assignee: Avery Dennison Corporation
• Inventors: Chang, Eng-Pi, Chu, Philip Yi Zhi, Chuang, Hsiao Ken, Huang, Kejian (Kevin), Lang, Michael, Mehrabi, Reza, Sieloff, Ronald F., Spilizewski, Karen L., Wisniewski, Mark
• Primary Examiner(s): Johnson, Christina
• Assistant Examiner(s): HUDA, SAEED M
• Application Number:
  US11/050,116
• Publication Number:
  US 20050178760A1
• Time in Patent Office: 3,169 Days
• Field of Search: 264/409, 264/405, 264/402, 264/327, 264/337, 264/492, 264/297.8, 264/319, 264/481, 604/272, 425/407, 425/348.R
• US Class Current: 264/481
• 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: B29C 2035/0822 using IR radiation
• CPC Class Codes: B29C 2059/023 Microembossing
• CPC Class Codes: B29C 2793/0045 Perforating
• CPC Class Codes: B29C 35/0272 using lost heating elements, i.e. heating means incorporated and remaining in the formed article for preforms with internal stresses B29C61/0625; joining using lost heating elements B29C65/34; making electrically conductive articles B29C70/882
• CPC Class Codes: B29C 35/0888 using transparant moulds
• CPC Class Codes: B29C 59/022 characterised by the disposition or the configuration, e.g. dimensions, of the embossments or the shaping tools therefor
• CPC Class Codes: B29C 59/04 using rollers or endless belts
• CPC Class Codes: B29L 2031/737 Articles provided with holes, e.g. grids, sieves nets B29L2028/00
• CPC Class Codes: B29L 2031/7544 Injection needles, syringes
• CPC Class Codes: B29L 2031/756 Microarticles, nanoarticles

Abstract

A method of making a microneedle array structure (20) comprising a plurality of simultaneously formed microneedles (24), each microneedle (24) having a protrusion (32) and a passageway (34) extending therethrough. The method comprises the steps of pressing an embossable sheet material between a complimentary tools and radiantly heating the sheet material using radiant energy from a radiant energy source. One tool is relatively-radiantly-transparent, and another tool and/or the sheet material is relatively-radiantly-absorptive.

Claims

1. A method of making a microneedle having a protrusion and passageway extending therethrough, said method comprising the steps of:

pressing an embossable, sheet material that is one of radiantly transparent or radiantly absorptive between a first radiant transparent tool having a recess which defines the protrusion and a second tool having a projection which defines the passageway;

wherein the second tool can be radiantly-transparent or radiantly-absorptive; and

radiantly heating the sheet material by using radiant energy from a vertically movable radiant energy source disposed above the first tool and below the second tool;

wherein the first tool is radiantly-transparent and the radiant energy passes there through to the sheet material; and

wherein at least one of the sheet material and the second tool is radiantly-absorptive.

2. A method as set forth in claim 1, wherein the radiant energy source supplies near-infrared energy.

3. A method as set forth in claim 1, wherein the radiant energy source includes a blackbody emitter having a temperature of at least 2000 K.

4. A method as set forth in claim 1, wherein said pressing step is performed by a press comprising an upper press incorporating the first tool and a lower press incorporating the second tool.

5. A method as set forth in claim 1, wherein said pressing step is performed by a pair of belts comprising an upper belt incorporating the first tool and a lower belt incorporating the second tool.

6. A method as set forth in claim 1, wherein the first tool is made of a thermoplastic, a thermoset polymer material, glass, or quartz.

7. A method as set forth in claim 1, wherein the sheet material includes a dopant that increases radiant absorptivity.

8. A method as set forth in claim 7, wherein the first tool is made of a thermoplastic, a thermoset polymer material, glass, or quartz.

9. A method as set forth in claim 1, wherein the second tool is made of a thermoplastic, a thermoset polymer material, glass, or quartz.

10. A method as set forth in claim 1, wherein the first tool comprises a plurality of recesses, and wherein the second tool comprises a plurality of projections, whereby said pressing steps and said radiant heating steps result in a microneedle array structure comprising a plurality of simultaneously formed microneedles.

11. A method as set forth in claim 1, wherein the recess in the first tool and the projection in the second tool are sized and shaped so that the passageway will extend through the tip of the protrusion.

12. A method as set forth in claim 1, wherein the recess in the first tool and the projection in the second tool are sized and shaped so that the passageway is centrally located in the protrusion.

13. A method as set forth in claim 1, wherein the recess in the first tool and the projection in the second tool are sized and shaped so that the passageway does not extend through the tip of the protrusion.

14. A method as set forth in claim 1, wherein the first tool also has a projection to form an indent surrounding the protrusion.

15. A method of making a microstructure having a protrusion and a passageway extending through the protrusion, said method comprising the steps of:

pressing an embossable sheet material that is one of radiantly transparent or radiantly absorptive between a first tool having a recess which defines the protrusion and a second tool wherein the second tool can be radiantly-transparent or radiantly-absorptive having a projection which defines the passageway; and

radiantly heating the sheet material by using radiant energy from a vertically movable radiant energy source by heaters disposed above the first tool and below the second tool;

wherein the first tool is radiantly-transparent and the radiant energy passes therethrough to the sheet material; and

wherein at least one of the sheet material and the second tool is radiantly-absorptive.

16. A method as set forth in claim 15, wherein the sheet material is radiantly-transparent and the second tool is radiantly-absorptive.

17. A method as set forth in claim 15, wherein the sheet material is radiantly-absorptive.