Methods and systems for loading an implantable medical device with beneficial agent

• US 20050287287A1
• Filed: 06/24/2004
• Published: 12/29/2005
• Est. Priority Date: 06/24/2004
• Status: Abandoned Application

• Current Assignee: Innovational Holdings, LLC
• Original Assignee: Innovational Holdings, LLC
• Inventors: Shanley, John F., Parker, Theodore L.
• Application Number:
  US10/876,520
• Publication Number:
  US 20050287287A1
• Time in Patent Office: Days
• US Class Current: 427/2.21
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2210/0076 multilayered, e.g. laminated structures
• CPC Class Codes: A61F 2240/001 Designing or manufacturing processes
• CPC Class Codes: A61F 2250/0068 the pharmaceutical product being in a reservoir

Abstract

An implantable medical device loading method is used to deposit layers into a plurality of holes in the implantable device in a stepwise manner to achieve extended and controllable delivery of drugs from the holes in the device. Each layer is deposited in a liquid form and is then solidified. The depositing and solidifying steps are repeated with the same or different solutions to achieve a controlled drug delivery matrix within the holes. To achieve increased uniformity of the initial layers improved wetting characteristics are desired. The selection and control of the surface energies of one or more of the surfaces within the holes and the surface tension of the filling solution allow the system to achieve the desired wetting characteristics.

Claims

1. A method of loading an implantable medical device with a beneficial agent, the method comprising:

providing an implantable device body having a plurality of through holes;

substantially sealing a bottom of the plurality of holes with a temporary sealing member, the temporary sealing member having a surface energy; and

loading a fluid beneficial agent into the holes, wherein a surface tension of the fluid beneficial agent is less than the surface energy of the sealing member to achieve wetting of the temporary sealing member.

2. The method of claim 1, wherein the temporary sealing member is resilient.

3. The method of claim 1, wherein the temporary sealing member is a mandrel.

4. The method of claim 3, further comprising a step of treating the mandrel to increase the surface energy of the mandrel surface.

5. The method of claim 1, further comprising a step of treating the temporary sealing member to increase the surface energy of the temporary sealing member.

6. The method of claim 5, wherein the step of treating comprises exposing at least a portion of the surface of the temporary sealing member to a chemically oxidizing environment for a time sufficient to increase the surface energy of the temporary sealing member by at least 2 dynes/cm.

7. The method of claim 6, wherein the chemically oxidizing environment comprises a plasma comprising an inert process gas and an oxidizing process gas.

8. The method of claim 6, wherein the step of exposing to a chemically oxidizing environment comprises corona discharge or electrical discharge in an oxidizing gas.

9. The method of claim 5, wherein the of step treating the temporary sealing member comprises at least one of flame oxidation treatment, solution oxidation treatment, corona discharge treatment, light treatment, and coating.

10. The method of claim 9, wherein a step of extracting the temporary sealing member using a solvent preceeds the step of treating.

11. The method of claim 5, wherein a step of extracting the temporary sealing member using a solvent preceeds the step of treating.

12. The method of claim 1, wherein the fluid beneficial agent comprises a polymer and a solvent.

13. The method of claim 1, wherein the fluid beneficial agent comprises a polymer in fluid form.

14. The method of claim 1, wherein the fluid beneficial agent comprises a drug.

15. The method of claim 1, wherein the implantable device body is formed of a metal, and the temporary sealing member is formed of a material having a surface energy lower than that of the metal.

16. A system for loading an implantable medical device with a beneficial agent, the system comprising:

an implantable medical device having holes therein;

bottom surfaces of the holes formed of a different material than the implantable medical device, the bottom surfaces of the holes having a surface energy;

a dispenser for dispensing a fluid solution of beneficial agent into the holes; and

a supply of the fluid solution connected to the dispenser, wherein the fluid solution has a surface tension less than the surface energy of the bottom surfaces of the holes.

17. The system of claim 16, wherein the bottom surfaces of the holes are formed by a temporary sealing member.

18. The system of claim 17, wherein the temporary sealing member is a mandrel.

19. The system of claim 17, wherein the temporary sealing member is resilient.

20. The system of claim 16, wherein the fluid solution comprises a polymer and a solvent.

21. The system of claim 16, wherein the fluid solution comprises a polymer in fluid form.

22. The system of claim 16, wherein the fluid solution comprises a drug.

23. The system of claim 16, wherein the implantable medical device is formed of a metal, and the bottom surfaces of the holes are formed of a resilient material.

24. A method of loading an implantable medical device with a beneficial agent, the method comprising:

providing an implantable device body having a plurality of through holes;

providing a temporary sealing member for sealing a bottom of the plurality of hole, the temporary sealing member having a resilient sealing surface;

treating the temporary sealing member to removed compounds which decrease the surface energy of the material;

substantially sealing a bottom of the plurality of holes with the temporary sealing member; and

loading a fluid beneficial agent into the holes.

25. The method of claim 24, wherein the step of treating the temporary sealing member comprises placing the temporary sealing member into a solvent which extracts oils from the temporary sealing member.

26. The method of claim 25, wherein the solvent extraction step is repeated until a surface energy of the sealing member is greater than a surface tension of the fluid beneficial agent.