Micro-needles and methods of manufacture and use thereof

• US 6,749,792 B2
• Filed: 07/09/2001
• Issued: 06/15/2004
• Est. Priority Date: 07/09/2001
• Status: Expired due to Fees

• Current Assignee: Lifescan Incorporated (Duv Holding Corporation)
• Original Assignee: Lifescan Incorporated (Duv Holding Corporation)
• Inventors: Olson, Lorin
• Primary Examiner(s): Colaianni, Michael
• Assistant Examiner(s): HUSON, MONICA ANNE
• Application Number:
  US09/901,535
• Publication Number:
  US 20030009113A1
• Time in Patent Office: 1,072 Days
• Field of Search: 264/328.1, 264/144, 425/577, 164/464, 164/47
• US Class Current: 264/328.1
• CPC Class Codes: A61B 2010/008 Interstitial fluid
• CPC Class Codes: A61B 5/14514 using means for aiding extraction of interstitial fluid, e.g. microneedles or suction
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• CPC Class Codes: A61B 5/150282 for piercing elements, e.g. blade, lancet, canula, needle
• CPC Class Codes: A61B 5/150984 Microneedles or microblades
• 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

Abstract

A micro-needle is provided which is particularly useful for the minimally invasive sampling of a biological fluid and/or the minimally invasive delivery of a drug or other formulation across the skin. The micro-needle has a structure having a base at a proximal end and a vertex at a distal end, and an open lumen extending there through and through which fluid may be transferred. The structure defines a structural axis that intersects the lumenal axis defined by the open lumen. The point of intersection between these axes is at a point below the vertex of the micro-needle to provide a sharp apex at the distal end of the micro-needle and defines the general configuration of the distal end of the micro-needle, which may be selected or customized depending on the intended use of the microneedle. The micro-needle may be integral with a measurement device for measuring the concentration of a constituent within sampled biological fluid and/or with a fluid reservoir for containing a fluid to be delivered, and may also be used in conjunction with a remote control means. Methods of making and using the micro-needle of the present invention as well as kits comprising one or more of the micro-needles are also provided.

Claims

1. A method of manufacturing a micro-needle structure for penetrating the skin and other tissue barriers, said method comprising:

providing a suitable material from which said micro-needle structure can be fabricated by at least one micro-replication technique;

fabricating said micro-needle structure from said suitable material by said at least one micro-replication technique, wherein said micro-needle structure comprises a conical configuration comprising a proximal end defining a base having a center and a distal end having a vertex comprising a sharp tip, wherein said base has a diameter in the range from about 100 to 2,000 μ

m and wherein a line extending from said center of the base to said vertex defines a structural axis having a length in the range from about 100 to 10,000 μ

m and

forming open lumen within said micro-needle structure, said open lumen defining a lumenal axis and extending from said base to said vertex, wherein a distal end of said open lumen intersects said vertex and wherein said lumenal axis and said structural axis intersect at an intersection angle.

2. The method of claim 1, wherein said open lumen is formed during the step of fabricating.

3. The method of claim 1 further comprising forming a selectively angled tip at said vertex.

4. The method of claim 1 wherein said suitable material is chosen from the group of a plastic and a resin.

5. The method of claim 1 wherein said suitable material is chosen from the group of acrylic, polyacrylates, polycarbonate, epoxies, polyesters polyetheretherketone, polyvinylchloride, polyolefins and liquid crystalline polyesters.

6. The method of claim 4 wherein said at least one micro-replication technique comprises injection molding.

7. The method of claim 1 wherein said suitable material comprises a metal.

8. The method of claim 1 the diameter of said open lumen is configured to exert a capillary force on a fluid present at said distal end of said open lumen.

9. The method of claim 1, wherein said vertex defines a vertex angle wherein said vertex angle is greater than twice the intersection angle.

10. The method of claim 3 wherein said selectively angled tip comprises a beveled edge.

11. A method of manufacturing a micro-needle structure, said method comprising:

providing a plastic material;

fabricating said micro-needle structure by injection molding said plastic material, wherein said micro-needle structure comprises an oblique cone configuration having a base and a vertex comprising a sharp tip;

forming an open lumen within said micro-needle structure, said open lumen extending from said base to said vertex wherein a distal end of said open lumen intersects said vertex; and

wherein said vertex defines a vertex angle,

a line extending from a center of said base to said vertex defines a structural axis, and

said open lumen defines a lumenal axis, wherein said lumenal axis and said structural axis intersect at an intersection angle.

12. The method of claim 11, wherein:

said vertex angle is greater than twice the intersection angle.

13. A method of manufacturing a device comprising a micro-needle structure, said method comprising:

providing a suitable material from which said micro-needle structure can be fabricated by at least one micro-replication technique;

fabricating said micro-needle structure from said suitable material by said at least one micro-replication technique, wherein said micro-needle structure comprises an oblique cone configuration having a base and a vertex configured for penetrating the skin and other tissue barriers;

forming an open lumen within said micro-needle structure, said open lumen extending from said base to said vertex wherein a distal end of said open lumen intersects said vertex;

wherein said vertex defines a vertex angle,

a line extending from a center of said base to said vertex defines a structural axis, and

said open lumen defines a lumenal axis, wherein said lumenal axis and said structural axis intersect at an intersection angle, and

integrating said micro-needle structure with another structure wherein said open lumen is in fluid communication with said other structure.

14. The method of claim 13, wherein said other structure comprises provided with means for receiving fluid and measuring a constituent of fluid received therein.

15. The method of claim 13, wherein said other structure comprises a chamber for holding a fluid therein.

16. The method of claim 15, wherein said fluid is a therapeutic agent.

17. The method of claim 13, further comprising fabricating a plurality of said micro-needle structures and integrating said plurality with said other structure wherein said open lumen of each said micro-needle structure is in fluid communication with said other structure.

18. The method of claim 13, wherein:

said vertex angle is greater than twice the intersection angle.