Method of manufacturing a medical device having a porous coating thereon

• US 20060088567A1
• Filed: 10/27/2004
• Published: 04/27/2006
• Est. Priority Date: 10/27/2004
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Warner, Robert, Thiesen-Toupal, Jesse Christian, Arney, Michael
• Granted Patent: US 7,862,835 B2
• Time in Patent Office: Days
• US Class Current: 424/422
• CPC Class Codes: A61L 2300/41 Anti-inflammatory agents, e.g. NSAIDs
• CPC Class Codes: A61L 2300/416 Anti-neoplastic or anti-proliferative or anti-restenosis or anti-angiogenic agents, e.g. paclitaxel, sirolimus
• CPC Class Codes: A61L 2300/602 Type of release, e.g. controlled, sustained, slow
• CPC Class Codes: A61L 2300/606 Coatings
• CPC Class Codes: A61L 2300/802 Additives, excipients, e.g. cyclodextrins, fatty acids, surfactants
• CPC Class Codes: A61L 27/34 Macromolecular materials
• CPC Class Codes: A61L 27/54 Biologically active materials, e.g. therapeutic substances A61L27/227 takes precedence
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 29/085 Macromolecular materials
• CPC Class Codes: A61L 29/146 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 29/16 Biologically active materials, e.g. therapeutic substances A61L29/048 takes precedence
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: A61L 31/146 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 31/16 Biologically active materials, e.g. therapeutic substances A61L31/047 takes precedence

Abstract

Methods of manufacturing drug-coated medical devices having a porous coatings thereon. The pores are created by solid particle additives added to a mixture comprising a solvent, a drug, and a polymer to create a suspension, which is applied to the medical device. The method includes adding a surfactant to the mixture to prevent or decrease flocculation of the solid particle additives. Another method is provided that includes spraying a suspension on a medical device that comprises solid particle additives, a drug, and a polymer and analyzing the distribution of the solid particle additives in the suspension.

Claims

1. A method of manufacturing a medical device having a coating containing pores, the method comprising:

preparing a mixture comprising a solvent, a drug, and a polymer;

dispersing solid particle additives in the mixture to form a suspension comprising dispersed solid particle additives; and

applying the suspension on a medical device to form a coating containing pores on the medical device, wherein the pores are created by the solid particle additives.

2. The method of claim 1, wherein the solid particle additives are insoluble in the mixture.

3. The method of claim 1, wherein dispersing the solid particle additives comprises:

adding a surfactant to the mixture; and

adding the solid particle additives to the mixture comprising the surfactant to form a suspension comprising dispersed solid particle additives.

4. The method of claim 3, wherein the surfactant is TWEEN 86®

, TWEEN 80®

, TWEEN 20°

, or oleic acid.

5. The method of claim 1, wherein dispersing the solid particle additives comprises physically agitating the solid particle additives.

6. The method of claim 1, wherein the coating comprises a network of interconnected pores.

7. The method of claim 1, wherein the coating has an outer surface and at least a portion of the pores are on the outer surface.

8. The method of claim 1, wherein applying the suspension comprises spraying the suspension on at least a portion of the medical device.

9. The method of claim 1, wherein the solid particle additives comprise a metallic oxide, a biocompatible polymer, a biologically active ceramic, a biologically compatible ceramic, or a salt.

10. The method of claim 9, wherein the metallic oxide is selected from the group consisting of titanium oxide, barium sulfate, silicon oxide, platinum oxide, and iridium oxide.

11. The method of claim 9, wherein the biocompatible polymer is selected from the group consisting of polylactic acid, polylactide, polygalactide, and polysaccaride.

12. The method of claim 9, wherein the biologically compatible ceramic is selected from the group consisting of silica and fumed silica.

13. The method of claim 9, wherein the biologically active ceramic is selected from the group consisting of hydroxyapatite and BIOGLASS®

.

14. The method of claim 9, wherein the salt is selected from the group consisting of lithium halide salt, sodium halide salt, potassium halide salt, and calcium halide salt.

15. The method of claim 1, wherein the solid particle additive has anti-inflammatory properties.

16. The method of claim 15, wherein the solid particle additive is selected from the group consisting of iridium oxide, platinum oxide, palladium oxide, ruthenium oxide, rhodium oxide, rhenium oxide, Raney cobalt, Raney nickel, copper chromite, and BIOGLASS®

.

17. The method of claim 1, wherein the solid particle additives are carbon dioxide particles.

18. The method of claim 1, wherein the solid particle additives are non-steroid anti-inflammatory drugs.

19. The method of claim 1, wherein the polymer is a block polymer.

20. The method of claim 19, wherein the block polymer is styrene-isobutylene-styrene.

21. The method of claim 1, wherein the medical device is a stent.

22. The method of claim 1, further comprising allowing the solid particle additives to evaporate after applying the suspension on the medical device.

23. The method of claim 1, wherein between about 50% to 100% of the drug is released from the medical device.

24. A method of manufacturing a medical device having a coating containing pores, the method comprising:

preparing a suspension comprising solid particle additives, a drug, and a polymer;

spraying the suspension on a medical device to form a coating containing pores on the medical device, wherein the pores are created by the solid particle additives; and

analyzing the distribution of the solid particle additives in the suspension being sprayed on the medical device.

25. The method of claim 24, wherein the distribution of the solid particle additives are analyzed by phase doppler analysis.

26. The method of claim 24, wherein between 50% to 100% of the drug is released from the medical device.