Rare limiting barriers for implantable medical devices

• US 7,087,263 B2
• Filed: 10/09/2002
• Issued: 08/08/2006
• Est. Priority Date: 10/09/2002
• Status: Expired due to Fees

• Current Assignee: Advanced Cardiovascular Systems Incorporated
• Original Assignee: Advanced Cardiovascular Systems Incorporated
• Inventors: Dehnad, Houdin, Tang, Fuh-Wei, Hossainy, Syed F A
• Primary Examiner(s): Sheikh, Humera N.
• Application Number:
  US10/269,004
• Publication Number:
  US 20040072922A1
• Time in Patent Office: 1,399 Days
• Field of Search: 514/772.4, 424/400, 427/2.1
• US Class Current: 427/2.1
• CPC Class Codes: A61L 2420/08 Coatings comprising two or more layers
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: A61L 31/16 Biologically active materials, e.g. therapeutic substances A61L31/047 takes precedence
• CPC Class Codes: C08L 29/04 Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids

Abstract

A coating for a medical device, particularly for a drug eluting stent, is described. The coating comprises a polymer having a weight-average molecular weight between about 200,000 and about 250,000 Daltons or a polydispersity index between about 2.6 and about 3.0.

Claims

1. A coating on an implantable medical device, the coating comprising poly(ethylene-co-vinyl alcohol) having a weight-average molecular weight between about 200,000 and about 250,000 Daltons and a polydispersity index between about 2.6 and about 3.0.

2. The coating of claim 1, wherein the implantable medical device is a stent.

3. The coating of claim 1, additionally comprising a therapeutic substance.

4. The coating of claim 3, wherein the therapeutic substance is selected from the group consisting of rapamycin, 40-O-(2-hydroxy)ethyl-rapamycin, 40-O-(3-hydroxy)propyl-rapamycin, 40-O-[2-(2-hydroxy)ethoxy]ethyl-rapamycin, and 40-O-tetrazole-rapamycin.

5. The coating of claim 1, wherein the coating comprises a first layer and a second layer disposed over the first layer, wherein the first layer includes a polymer and a therapeutic substance and the second layer includes the poly(ethylene-co-vinyl alcohol) having a weight-average molecular weight between about 200,000 and about 250,000 Daltons and a polydispersity index between about 2.6 and about 3.0.

6. The coating of claim 5, wherein the ratio between the therapeutic substance and the polymer in the first layer is between about 1:

1 and about 1;

25.

20. The coating of claim 1, further comprising a topcoat that includes poly(ethylene glycol), hyaluronic acid, heparin or a combination thereof.

21. The coating of claim 1, further comprising a topcoat treated by an annealing process.

7. A coating on an implantable medical device, the coating comprising poly(ethylene-co-vinyl alcohol) having a polydispersity index between about 2.6 and about 3.0.

8. The coating of claim 7, wherein the implantable medical device is a stent.

9. The coating of claim 7, additionally comprising a therapeutic substance.

10. The coating of claim 9, wherein the therapeutic substance is selected from the group consisting of rapamycin, 40-O-(2-hydroxy)ethyl-rapamycin, 40-O-(3-hydroxy)propyl-rapamycin, 40-O-[2-(2-hydroxy)ethoxy]ethyl-rapamycin, and 40-O-tetrazole-rapamycin.

11. The coating of claim 7, wherein the coating comprises a first layer and a second layer disposed over the first layer, wherein the first layer includes a polymer and a therapeutic substance and the second layer includes the poly(ethylene-co-vinyl alcohol) having a polydispersity index between about 2.6 and about 3.0.

12. The coating of claim 11, wherein the ratio between the therapeutic substance and the polymer in the first layer is between about 1:

1 and about 1;

25.

22. The coating of claim 7, further comprising a topcoat treated by an annealing process.

13. A coating on an implantable medical device, the coating comprising a layer including a polymer having a polydispersity index between about 2.6 and about 3.0 and a therapeutic substance, wherein the ratio between the therapeutic substance and the polymer in the layer is between about 1:

1 and about 1;

25.

14. The coating of claim 13, wherein the implantable medical device is a stent.

15. The coating of claim 13, wherein the therapeutic substance is selected from a group consisting of rapamycin, 40-O-(2-hydroxy)ethyl-rapamycin, 40-O-(3-hydroxy)propyl-rapamycin, 40-O-[2-(2-hydroxy)ethoxy]ethyl-rapamycin, and 40-O-tetrazole-rapamycin.

16. The coating of claim 13, additionally comprising a second layer disposed over the layer, the second layer comprising poly(ethylene-co-vinyl alcohol) having a weight-average molecular weight between about 200,000 and about 250,000 Daltons or a polydispersity index between about 2.6 and about 3.0.

17. A method of coating a stent comprising forming a coating comprising a copolymer of ethylene and vinyl alcohol on the stent, the copolymer having a weight-average molecular weight between about 200,000 and about 250,000 Daltons and a polydispersity index between about 2.6 and about 3.0.

18. The method of claim 17, wherein the coating further comprises a layer including a polymer and a therapeutic substance incorporated therein.

19. The method of claim 18, wherein the therapeutic substance is selected from the group consisting of rapamycin, 40-O-(2-hydroxy)ethyl-rapamycin, 40-O-(3-hydroxy)propyl-rapamycin, 40-O-[2-(2-hydroxy)ethoxy]ethyl-rapamycin, and 40-O-tetrazole-rapamycin.