Process for forming a porous drug delivery layer

• US 6,904,658 B2
• Filed: 06/02/2003
• Issued: 06/14/2005
• Est. Priority Date: 06/02/2003
• Status: Expired due to Fees

• Current Assignee: Electroformed Stents, Inc.
• Original Assignee: Electroformed Stents, Inc.
• Inventors: Hines, Richard A.
• Primary Examiner(s): Bryant, David P.
• Application Number:
  US10/452,891
• Publication Number:
  US 20040237282A1
• Time in Patent Office: 743 Days
• Field of Search: 294/23, 294/60, 295/272, 623/1.15, 623/1.42, 205/112, 205/122, 427/2.24
• US Class Current: 29/423
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2002/91533 characterised by the phase between adjacent bands
• CPC Class Codes: A61F 2230/0013 Horseshoe-shaped, e.g. crescent-shaped, C-shaped, U-shaped
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: A61F 2250/0068 the pharmaceutical product being in a reservoir
• CPC Class Codes: C25D 1/00 Electroforming
• CPC Class Codes: C25D 5/48 After-treatment of electroplated surfaces
• CPC Class Codes: C25D 7/00 Electroplating characterised by the article coated
• CPC Class Codes: Y10T 29/4981 Utilizing transitory attached element or associated separate material
• CPC Class Codes: Y10T 29/49885 with coating before or during assembling
• CPC Class Codes: Y10T 29/49888 Subsequently coating
• CPC Class Codes: Y10T 29/49982 Coating

Abstract

The present invention is directed to a process for forming a drug delivery device by electroplating onto a substrate a porous layer having pores of a controlled size and density and loading a drug into the pores. Preferably the drug delivery device is a gold stent plated with a gold porous layer.

Claims

1. A process for forming a drug delivery device comprising:

providing a substrate; and

electroplating onto said substrate a porous layer having openings connected to pores of a controlled size and nature,

wherein said electroplating step comprises electroplating a material that is substantially free of the drug to be delivered, and

wherein the size and nature of said pores is controlled through controlling the current wave form and plating time in said electroplating step.

2. The product of the process of claim 1.

3. The process of claim 1, further comprising after said electroplating step, the step of loading one or more drugs into said pores.

4. The product of the process of claim 3.

5. The process of claim 3, wherein said drug is selected from the group consisting of dexamethasone, imatinib mesylate, sirolimus, aspirin, heprin and paclitaxel and combinations thereof.

6. The process of claim 1, wherein said drug delivery device is a stent.

7. The product of the process of claim 6.

8. The process of claim 1, wherein said electroplating step comprises electroplating a metal selected from the group consisting of gold, nickel, silver, copper, tin, palladium, platinum, rhodium, iridium, alloys thereof and combinations thereof.

9. The process of claim 8 wherein said metal is gold.

10. The process of claim 1, further comprising between said providing step and said step of electroplating said porous layer, the step of electroplating a solid layer onto said substrate.

11. The process of claim 10, wherein said substrate is a sacrificial mandrel and further comprising after said step of electroplating said solid layer, the step of dissolving said mandrel.

12. The process of claim 1, wherein said substrate is a medical device.

13. The process of claim 12, wherein said medical device is a stent.

14. The process of claim 1, further comprising the step of over-plating an orifice deposit on said porous layer.

15. The process of claim 1, further comprising the step of forming a top layer over said porous layer.

16. The process of claim 15, wherein said forming step comprises peening said porous layer to form said top layer.

17. The process of claim 15, wherein said forming step comprises applying a polymer over said porous layer.

18. A process for forming a drug delivery stent comprising:

providing a mandrel;

coating said mandrel with a resist;

exposing portions of said resist to a light pattern so as to form a stent pattern on said mandrel in said resist;

electroplating a stent having a percent porosity less than 1% on said mandrel;

electroplating a porous layer having openings connected to pores of a controlled size and nature on said stent; and

removing said resist and said mandrel,

wherein said electroplating said porous layer step comprises electroplating a material that is substantially free of the drug to be delivered, and

wherein the size and nature of said pores is controlled through controlling the current wave form and plating time in said electroplating said porous layer step.

19. The product of the process of claim 18.

20. A process for forming a drug delivery stent comprising:

providing a prefabricated stent; and

electroplating a porous layer having openings connected to pores of a controlled size and nature on said stent,

wherein said electroplating step comprises electroplating a material that is substantially free of the drug to be delivered, and

wherein the size and nature of said pores is controlled through controlling the current wave form and plating time in said electroplating step.

21. The product of the process of claim 20.

22. The process of claim 20, further comprising between said providing step and said electroplating step, the step of electroplating a metal having a percent porosity less than about 1% on said stent.

23. A process for forming a drug delivery device comprising:

providing a substrate;

electroplating onto said substrate a porous layer having pores of a controlled size and nature, wherein said porous layer has a percent porosity greater than about 1%; and

loading a drug into said pores,

wherein said electroplating step comprises electroplating a material that is substantially free of the drug to be delivered, and

wherein the size and nature of said pores is controlled through controlling the current wave form and plating time in said electroplating step.

24. The process of claim 23, wherein said drug delivery device is a stent.

25. A process for forming an implantable drug delivery device, comprising:

providing a sacrificial mandrel;

electroplating a porous layer on said mandrel to produce a vessel on said mandrel;

creating at least one hole in said vessel to expose a portion of said mandrel;

dissolving said mandrel;

loading said vessel with one or more drugs; and

sealing any of said holes.

26. The product of the process of claim 25.