Medical Device Having Coating With Zeolite Drug Reservoirs

• US 20070259017A1
• Filed: 05/05/2006
• Published: 11/08/2007
• Est. Priority Date: 05/05/2006
• Status: Active Grant

• Current Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Original Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Inventors: Francis, Richard
• Granted Patent: US 7,691,400 B2
• Time in Patent Office: Days
• US Class Current: 424/423
• 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 2420/04 Coatings containing a composite material such as inorganic/organic, i.e. material comprising different phases
• 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

A medical device having a drug-eluting coating that includes a pharmaceutical compound or, more generally, a therapeutic material housed within pores of a zeolite carrier. The zeolite carrier has an open porous structure with reservoirs for holding the therapeutic material. The therapeutic material loaded zeolites may be suspended or dispersed within a bioerodible polymer matrix to provide controlled delivery of the therapeutic material. Zeolite drug carriers may have enhanced or optimally engineered pore sizes for a particular therapeutic material and release profile. Along with a therapeutic material, reservoirs of a zeolite drug delivery system may include a release agent. The release agent may be used to entrap the therapeutic material until such time as a triggering condition is met that prompts the release agent to activate and thereby release the therapeutic material from the zeolite reservoir.

Claims

1. A medical device having at least one surface for contacting a bodily tissue, organ or fluid, the medical device comprising:

a substrate having a contacting surface; and

a drug-eluting coating on at least a portion of the contacting surface, wherein the coating is comprised of a polymer having zeolites dispersed there through and wherein a porous structure of the zeolites includes reservoirs containing a release agent and a therapeutic material.

2. The medical device of claim 1, wherein the release agent prevents the therapeutic material from exiting the reservoir until a triggering condition is met.

3. The medical device of claim 2, wherein the triggering condition is contact of the release agent with a bodily fluid.

4. The medical device of claim 2, wherein the triggering condition is a change in pH proximate the release agent.

5. The medical device of claim 1, wherein the polymer is bioerodible.

6. The medical device of claim 1, wherein the medical device is an implantable medical device.

7. The medical device of claim 6, wherein the implantable medical device is a stent for implanting in a vessel system.

8. A drug-eluting stent for implanting in a body lumen comprising:

a radially expandable stent structure; and

a coating on at least a portion of a surface of the stent structure, wherein the coating is comprised of a polymer having zeolites dispersed there through and wherein a porous structure of the zeolites includes reservoirs containing a therapeutic material.

9. The stent of claim 8, wherein the reservoirs also contain a release agent for preventing the release of the therapeutic material from the reservoir until a triggering condition is met.

10. The stent of claim 9, wherein the triggering condition is contact of the release agent with a bodily fluid.

11. The stent of claim 9, wherein the triggering condition is a change in pH proximate the release agent.

12. The stent of claim 11, wherein the polymer is a bioerodible polymer having lactic acid as a degradation product for providing the change in pH.

13. The stent of claim 8, wherein the therapeutic material is a pharmaceutical compound.

14. The stent of claim 13, wherein the coating further comprises:

an outer layer having zeolites containing a first pharmaceutical compound; and

an inner layer having zeolites containing a second pharmaceutical compound.

15. The stent of claim 14, wherein the outer layer is of a bioerodible polymer and the first pharmaceutical compound is selected from a group consisting of an anti-coagulant drug and an anti-inflammatory drug.

16. The stent of claim 15, wherein the second pharmaceutical compound is selected from a group consisting of an anti-proliferative and a pro-healing agent to promote rapid re-endothelialization.

17. A drug-eluting coating of a medical device, the coating comprising:

a polymer dispersed with zeolite drug carriers, wherein a porous structure of the zeolite drug carriers includes reservoirs containing a pharmaceutical compound.

18. The coating of claim 17, further comprising:

an outer layer of a bioerodible polymer having zeolite drug carriers with a first pharmaceutical compound; and

an inner layer of a polymer matrix having zeolite drug carriers with a second pharmaceutical compound.