Methods and moulds for use in fabricating side-ported microneedles

• US 20100305516A1
• Filed: 03/12/2004
• Published: 12/02/2010
• Est. Priority Date: 03/12/2004
• Status: Active Grant

• Current Assignee: Agency For Science Technology and Research
• Original Assignee: Agency For Science Technology and Research
• Inventors: Wang, Minghua, Tan, Pei Ying Joyce, Chen, Mei Ma, Li, Zhongli, Lim, Chee Yen, Xu, Yuan
• Granted Patent: US 8,671,544 B2
• Time in Patent Office: Days
• US Class Current: 604/272
• CPC Class Codes: A61M 2037/003 having a lumen
• CPC Class Codes: A61M 2037/0053 Methods for producing microneedles
• CPC Class Codes: A61M 37/0015 by using microneedles
• CPC Class Codes: B29C 2791/001 Shaping in several steps
• CPC Class Codes: B29C 2793/0009 Cutting out
• CPC Class Codes: B29C 33/0061 characterised by the configuration of the material feeding channel sprue channels for injection moulding B29C45/27
• CPC Class Codes: B29C 33/301 Modular mould systems [MMS], i.e. moulds built up by stacking mould elements, e.g. plates, blocks, rods B29C33/0088 takes precedence
• CPC Class Codes: B29C 33/3857 by making impressions of one or more parts of models, e.g. shaped articles and including possible subsequent assembly of the parts
• CPC Class Codes: B29C 33/40 Plastics, e.g. foam or rubber
• CPC Class Codes: B29C 33/424 Moulding surfaces provided with means for marking or patterning for injection moulding B29C45/372
• CPC Class Codes: B29C 33/56 Coatings , e.g. enameled or galvanised; Releasing, lubricating or separating agents in-mould coating B29C37/0028; using or applying separating agents B29C37/0067
• CPC Class Codes: B29C 59/026 of layered or coated substantially flat surfaces
• CPC Class Codes: B29L 2031/756 Microarticles, nanoarticles
• CPC Class Codes: B29L 2031/759 Needles medical needles B29L2031/7544
• CPC Class Codes: B81B 2201/055 Microneedles
• CPC Class Codes: B81C 99/009 Manufacturing the stamps or the moulds
• CPC Class Codes: C25D 1/02 Tubes; Rings; Hollow bodies
• CPC Class Codes: Y10T 29/49885 with coating before or during assembling
• CPC Class Codes: Y10T 29/4998 Combined manufacture including applying or shaping of fluent material
• CPC Class Codes: Y10T 29/49982 Coating
• CPC Class Codes: Y10T 29/49984 : and casting
• CPC Class Codes: Y10T 29/49986 : Subsequent to metal working
• CPC Class Codes: Y10T 29/49988 : Metal casting

Abstract

Side-ported microneedles are produced from a suitably shaped microneedle mould (40). A microneedle mould base (32) is made with a number of microneedle mould recesses (30) in it. One surface of the microneedle mould base (32) is coated with a seed layer (34). The microneedle mould base (32) contains two microneedle mould sheets (24, 26), which are separated to gain access to an internal surface of one of the microneedle mould sheets (24, 26). Side-port forming channels (38) are formed on one of the internal surfaces, intersecting with the recesses (30) within the relevant microneedle mould sheet (24). The two microneedle mould sheets (24, 26) are placed back together and joined together as a unitary microneedle mould (40). The microneedles are formed in the recesses (30) by depositing a microneedle layer (44) therein and on the surface with the seed layer (34). The microneedle layer (44) fails to deposit at side-port forming holes (42) where the side-port forming channels (38) intersect the recesses (30), which result in side-ports (46) in the moulded microneedles (52).

Claims

1. A method of manufacturing a microneedle mould for use in fabricating microneedles, comprising:

providing a microneedle mould base with recesses therein, the recesses corresponding to the microneedles to be fabricated and extending from a first surface of the microneedle mould base; and

forming side-port forming holes in the microneedle mould base, the side-port forming holes extend in side surfaces of the recesses within the microneedle mould base at side-port forming positions of the recesses.

2. A method according to claim 1, wherein the side-port forming holes extend in the sides of the recesses without extending to the tops or bottoms of the recesses.

3. A method according to claim 1, wherein the side-port forming holes extend in only one side surface of the individual recesses.

4. A method according to claim 3, wherein individual recesses are intercepted by the side-port forming holes at only one point.

5. A method according to claim 1, wherein the side-port forming holes extend in opposing side surfaces of the individual recesses.

6. A method according to claim 1, wherein the side-port forming holes extend in adjacent side surfaces of the individual recesses.

7. A method according to claim 1, further comprising providing a seed layer on the first surface of the microneedle mould base and in the recesses.

8. A method according to claim 7, wherein forming side-port forming holes in the microneedle mould base occurs after the seed layer is provided, thereby removing the seed layer from the side-port forming positions.

9. A method according to claim 7, wherein the seed layer is deposited after the side-port forming holes are formed in the microneedle mould base, the seed layer failing to deposit substantially on the side-port forming positions.

10. A method according to claim 7, wherein forming the side-port forming holes comprises:

providing the side surfaces of the recesses with discontinuities at the side-port forming positions of the recesses; and

depositing the seed layer after providing the side-port forming discontinuities, with the seed layer failing to deposit substantially on the side-port forming discontinuities.

11. A method according to claim 10, wherein providing the side surfaces of the recesses with discontinuities comprises forming portions of the side surfaces of the recesses that are generally orthogonal to the first surface of the mould base.

12. A method according to claim 11, wherein the generally orthogonal portions of the side surfaces of the recesses are formed with the recesses.

13. A method according to claim 10, wherein providing the side surfaces of the recesses with discontinuities comprises forming side-port forming channels in the mould base intercepting the recesses.

14. A method according to claim 1, wherein the side-port forming holes are formed where side-port forming channels in the mould base intercept the recesses in the mould base.

15. A method according to claim 13, wherein the side-port forming channels extend from one edge surface of the microneedle mould base to an opposing edge surface of the microneedle mould base, generally parallel to the first surface of the microneedle mould base.

16. A method according to claim 13, wherein the side-port forming channels extend between adjacent recesses.

17. A method according to claim 13, wherein:

the microneedle mould base comprises a plurality of overlaid mould base sheets; and

further comprising;

forming the side-port forming holes in the mould base, comprising;

separating the plurality of mould base sheets;

forming side-port forming channels in at least one of the opposing surfaces of at least one of the mould base sheets; and

overlaying the plurality of mould base sheets to reconstruct the microneedle mould base.

18. A method according to claim 17, wherein the side-port forming channels in at least one of the opposing surfaces are formed as grooves in the at least one of the opposing surfaces.

19. A method according to claim 17, wherein the microneedle mould base further comprises a separation layer between the or each two adjacent overlaid mould base sheets.

20. A method according to claim 19, further comprising removing the one or more separation layers prior to overlaying the plurality of mould base sheets to reconstruct the microneedle mould base.

21. A method according to claim 1, wherein the recesses are through-holes extending from the first surface of the microneedle mould base to an opposing second external surface.

22. A method according to claim 1, wherein providing a microneedle mould base comprises moulding the microneedle mould base on a master mould having a master mould base surface with a plurality of master mould needles protruding therefrom, the master mould needles corresponding to the recesses in the microneedle mould base.

23. A method according to claim 22, wherein the microneedle mould base is moulded on the master mould by hot pressing.

24. A method according to claim 22, further comprising providing the master mould.

25. A method according to claim 24, wherein providing the master mould comprises wire cutting the master mould from a master mould block.

40. A microneedle mould fabricated according to the method of claim 1.

47. A method of fabricating microneedles, comprising:

providing a microneedle mould, which microneedle mould is as defined in claim 40;

forming a microneedle layer onto a first surface of the microneedle mould and within the recesses of the microneedle mould, with gaps in the layers on the side-port forming holes; and

removing the microneedle layer from the microneedle mould, the portions of the microneedle layer corresponding to the side-port forming holes comprising microneedle side-ports.

49. A method according to claim 47, further comprising splitting the microneedle layer into a plurality of microneedle portions, each microneedle portion having one or more microneedles thereon.

50. A method according to claim 47, wherein forming the microneedle layer comprises electroplating, PVD, CVD, thermo-evaporation or electroless plating the microneedle layer onto the first surface of the microneedle mould and into the recesses.

51. A method according to claim 47, wherein removing the microneedle layer from the microneedle mould comprises peeling the microneedle layer off from the microneedle mould.

52. A method according to claim 47, wherein removing the microneedle layer from the microneedle mould comprises dissolving the microneedle mould.

53. One or more microneedles manufactured according to the method of claim 47.

26. A method of manufacturing a master mould for use in fabricating microneedles, comprising providing a master mould having a master mould base surface with a plurality of master mould needles protruding therefrom, the plurality of the master mould needles comprising at least one first side surface with a side-port forming portion thereon extending in a plane substantially orthogonal to the master mould base surface.

27. A method according to claim 26, wherein providing a master mould comprises cutting across a block of a first material in at least two different directions to provide the master mould comprising the master mould base surface with the plurality of master mould needles protruding therefrom.

28. A method according to claim 27, wherein the side-port forming portions are formed in the cutting across the block in at least two different directions.

29. A method according to claim 26, wherein cutting across the block in at least two different directions comprises an individual cut in each of the at least two directions.

30. A method according to claim 29, wherein individual cuts comprise:

a plurality of base cutting portions, cutting the master mould base surface;

a plurality of tip-ward cutting portions, cutting from the base cutting portions to what will become the tips of the master mould needles; and

a plurality of baseward cutting portions, cutting from what will become the tips of the master mould needles to the base cutting portions; and

wherein

individual base cutting portions are separated by a pair of a tipward cutting portion and a baseward cutting portion; and

at least one of each pair of first and second sloped cutting portions cuts a surface of a plurality of master mould needles.

31. A method according to claim 30, wherein the tipward and baseward cutting portions are continuous cuts in controlled directions.

32. A method according to claim 26, wherein the side-port forming portions are discontinuous with the rest of the first side surfaces on which the side-port forming portions extend.

33. A method according to claim 26, wherein individual first side surfaces comprise:

a first sloping portion from the master mould base surface;

the side-port forming portion; and

a second sloping portion from the side-port forming portion to the tip of the master mould needle.

34. A method according to claim 33, wherein at least one of the first and second sloping portions is planar.

35. A method according to claim 33, wherein at least one of the tipward and baseward cutting portions cuts the first and second sloping portions and the side-port forming portions.

36. A master mould for use in fabricating microneedles, which master mould is manufactured according to the method of claim 26.

38. A method of manufacturing a microneedle mould for use in fabricating microneedles, comprising moulding a microneedle mould base on a master mould, which master mould is as defined in claim 36, to provide recesses within the microneedle mould base, wherein

the recesses correspond to the microneedles to be fabricated;

the recesses extend from a first surface of the microneedle mould base; and

the recesses comprise side-port forming discontinuities extending on side surfaces thereof in planes that extend substantially orthogonal to the first surface of the microneedle mould base.

39. A method according to claim 38, further comprising providing a seed layer on the first surface of the microneedle mould base and on the side surfaces of the recesses, except substantially on the side-port forming discontinuities.

37. A master mould for use in fabricating microneedles, comprising:

a master mould base surface with a plurality of master mould needles protruding therefrom;

wherein

a plurality of the master mould needles comprise at least one first side surface with a side-port forming portion; and

the side-port forming portions extend on the first side surfaces of the master mould needles in planes that extends substantially orthogonal to the master mould base surface.

41. A microneedle mould comprising a microneedle mould base with a plurality of recesses extending from a first surface thereof and a plurality of side-port forming holes in the microneedle mould base, the side-port forming holes extending in side surfaces of the recesses within the microneedle mould base at side-port forming positions of the recesses.

42. A microneedle mould according to claim 41, wherein the side-port forming holes comprise the interception of side-port forming channels in the mould base and recesses in the mould base.

43. A microneedle mould according to claim 41, wherein the side-port forming holes comprise discontinuities in the side surfaces of the recesses.

44. A microneedle mould according to claim 43, wherein the discontinuities in the side surfaces of the recesses extend substantially orthogonally to the first surface of the microneedle mould base.

45. A microneedle mould according claim 41, wherein the side-port forming holes comprise discontinuities in the side surfaces of the recesses and the recesses comprise a seed layer on their side surfaces.

46. A microneedle mould according to claim 45, wherein the discontinuities comprise gaps in the seed layer.

48. A method according to claim 48, wherein the microneedle layer within the recesses is hollow, to form hollow microneedles, the hollow of the microneedles and the microneedle side-ports being in fluid communication.

54-60. -60. (canceled)