Device and method for enhancing transdermal flux of agents being sampled

• US 20020077584A1
• Filed: 12/14/2000
• Published: 06/20/2002
• Est. Priority Date: 12/16/1999
• Status: Active Grant

• Current Assignee: Felix Theeuwes, Michel J.N. Cormier, Wei-Qi Lin
• Original Assignee: Felix Theeuwes, Michel J.N. Cormier, Wei-Qi Lin
• Inventors: Theeuwes, Felix, Lin, Wei-Qi, Cormier, Michel J.N.
• Granted Patent: US 6,562,014 B2
• Time in Patent Office: Days
• US Class Current: 604/21
• CPC Class Codes: A61B 10/0045 Devices for taking samples of body liquids devices for taking blood samples A61B5/15
• CPC Class Codes: A61B 17/205 Vaccinating by means of needles or other puncturing devices
• CPC Class Codes: A61B 2010/0009 Testing for drug or alcohol abuse
• CPC Class Codes: A61B 2010/008 Interstitial fluid
• 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 5/150099 by negative pressure, other than vacuum extraction into a syringe by pulling on the piston rod or into pre-evacuated tubes
• CPC Class Codes: A61B 5/150221 Valves
• CPC Class Codes: A61B 5/150236 Pistons, i.e. cylindrical bodies that sit inside the syringe barrel, typically with an air tight seal, and slide in the barrel to create a vacuum or to expel blood
• CPC Class Codes: A61B 5/150244 Rods for actuating or driving the piston, i.e. the cylindrical body that sits inside the syringe barrel, typically with an air tight seal, and slides in the barrel to create a vacuum or to expel blood
• CPC Class Codes: A61B 5/150984 Microneedles or microblades
• CPC Class Codes: A61M 2037/0007 having means for enhancing the permeation of substances through the epidermis, e.g. using suction or depression, electric or magnetic fields, sound waves or chemical agents

Abstract

A transdermal agent sampling device is provided. The sampling device is comprised of a microblade array and a device for applying a partial vacuum. The microblade array comprises a sheet having a plurality of microblades for piercing the skin to a very shallow depth (i.e., 25 μm to 400 μm) to create microslits in the outermost stratum corneum layer of the skin. The partial vacuum applying device applies a partial vacuum in the range of about 0.1 to about 0.8 atm, and preferably about 0.3 to about 0.7 atm, for sampling a body analyte such as glucose in interstitial fluid. The partial vacuum is applied for a period of about 2 to about 30 seconds, and preferably about 5 to about 15 seconds. The interstial fluid is analyzed for body analyte (e.g., glucose) content or concentration.

Claims

1. An apparatus for piercing the stratum corneum and withdrawing a body fluid therethrough for sampling an agent in the fluid, comprising:

a piercing member having a plurality of stratum corneum-piercing microblades, wherein the microblades having a length sufficient to pierce the stratum corneum to a depth in the range of about 25 to about 400 μ

m, the microblades being arranged on a stratum corneum-contacting portion of the apparatus, the piercing member having a plurality of fluid flow pathways therethrough, and

a partial vacuum applying device connected to the piercing member for applying a partial vacuum in a range of about 0.1 to about 0.8 atm over a period of about 2 to about 30 seconds through the fluid flow pathways to the pierced stratum corneum for withdrawing the body fluid.

2. The apparatus of claim 1, wherein the agent is selected from the group consisting of body electrolytes, illicit drugs and glucose.

3. The apparatus of claim 1, the body fluid is interstitial fluid.

4. The apparatus of claim 3, wherein the body fluid is substantially free of blood.

5. The apparatus of claim 1, wherein the piercing member comprises a sheet having a multiplicity of openings therethrough and a multiplicity of microblades extending downward therefrom.

6. The apparatus of claim 5, wherein the microblades are located along peripheries of the openings through the sheet.

7. The apparatus of claim 1, wherein the piercing member comprises a plurality of spaced sheets, each of the sheets having a stratum corneum-contacting edge having a plurality of the microblades extending therefrom, the fluid flow pathways being voids between adjacent sheets.

8. The apparatus of claim 1, wherein the piercing member has about 20 to about 1000 microblades/cm².

9. The apparatus of claim 1, wherein the partial vacuum applying device applies a partial vacuum of about 0.3 to about 0.7 atm.

10. The apparatus of claim 1, wherein the partial vacuum applying device applies the partial vacuum for a period of about 5 to about 15 seconds.

11. The apparatus of claim 1, wherein the partial vacuum applying device comprises a suction cup sealingly mounted on the piercing member.

12. The apparatus of claim 11, wherein the suction cup is composed of a flexible material, the cup resiliently recovering its size and shape after applying a compressive force thereto.

13. The apparatus of claim 1, wherein the suction cup includes a one-way air valve.

14. The apparatus of claim 1, wherein the partial vacuum applying device comprises an animal venom extractor.

15. The apparatus of claim 14, wherein the animal venom extractor comprises a syringe body having a stratum corneum engaging skirt and a piston and plunger having an air passageway extending therethrough.

16. The apparatus of claim 1, wherein the partial vacuum applying device comprises a syringe body having an open stratum corneum-engaging end and a piston-plunger assembly having an air passageway extending therethrough, the syringe body also containing a spring-loaded plunger unit having the microblades mounted thereon.

18. The method of claim 17, wherein the agent is selected from the group consisting of body analytes, electrolytes, blood gases, illicit drugs, licit drugs and glucose.

19. The method of claim 17, the body fluid is interstitial fluid.

20. The method of claim 19, wherein the fluid is substantially free of blood.

21. The method of claim 17, wherein the piercing member comprises a sheet having a multiplicity of fluid flow pathways therethrough and a multiplicity of microblades extending therefrom.

22. The method of claim 21, wherein the partial vacuum is applied through the fluid flow pathways to withdraw the body fluid through the fluid flow pathways.

23. The method of claim 17, including collecting the body fluid.

24. The method of claim 17, wherein the partial vacuum is about 0.3 to about 0.7 atm.

25. The method of claim 17, wherein the partial vacuum is applied for a period of about 5 to about 15 seconds.

17. A method of sampling an agent, comprising:

a) piercing the stratum corneum with a piercing member having a plurality of microblades wherein the microblades having a length sufficient to pierce the stratum corneum to a depth in the range about 25 to about 400 μ

m;

b) applying a partial vacuum in the range of about 0.1 to about 0.8 atm to the pierced stratum corneum over a period of about 2 to about 30 seconds to withdraw a body fluid containing the agent; and

c) analyzing for the agent.