MULTI-LAYERED COATINGS AND METHODS FOR CONTROLLING ELUTION OF ACTIVE AGENTS

• US 20080075753A1
• Filed: 09/25/2007
• Published: 03/27/2008
• Est. Priority Date: 09/25/2006
• Status: Abandoned Application

• Current Assignee: Surmodics Incorporated
• Original Assignee: Surmodics Incorporated
• Inventors: Chappa, Ralph A.
• Application Number:
  US11/860,856
• Publication Number:
  US 20080075753A1
• Time in Patent Office: Days
• US Class Current: 424/426
• CPC Class Codes: A61L 2300/608 having two or more layers
• CPC Class Codes: A61L 2420/08 Coatings comprising two or more layers
• 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 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 65/04 Polyxylenes

Abstract

Embodiments of the invention include multi-layered coatings for controlling the elution rates of active agents and methods. In an embodiment, the invention includes a method of applying an elution control coating to a substrate. The method can include depositing a coating solution onto the substrate to form a base layer. The method can also include selecting a desired concentration of the solvent based on a desired elution rate. The method can further include removing solvent from the base layer to reach a desired concentration of the solvent and depositing a layer of parylene on the base layer. In an embodiment, the invention can include a medical device including a substrate, a base layer, and a porous layer. The base layer can include a polymeric matrix and an active agent dispersed within the polymeric matrix. The porous layer can include parylene. Other embodiments are also included herein.

Claims

1. A method of applying an elution control coating to a substrate comprising:

depositing a coating solution onto the substrate to form a base layer, the coating solution comprising an active agent, a polymer, and a solvent;

selecting a desired concentration of the solvent based on a desired elution rate;

removing solvent from the base layer to reach a desired concentration of the solvent; and

depositing a layer of parylene on the base layer.

2. The method of claim 1, wherein depositing a coating solution onto the substrate to form a base layer comprises spraying a coating solution onto the substrate.

3. The method of claim 1, the active agent comprising a macromolecule.

4. The method of claim 1, the active agent selected from the group consisting of peptides and proteins.

5. The method of claim 1, the active agent selected from the group consisting of antibodies and antibody derivatives.

6. The method of claim 1, the solvent comprising a non-polar solvent.

7. The method of claim 1, the solvent comprising a polar solvent.

8. The method of claim 1, wherein depositing a coating solution onto a substrate to form a base layer comprises simultaneously spraying a first coating solution onto the substrate from a first spray head and spraying a second coating solution onto the substrate from a second spray head.

9. The method of claim 8, the first coating solution comprising the active agent and the second coating solution comprising the polymer.

10. The method of claim 1, the polymer comprising a degradable polymer and a non-degradable polymer, the first coating solution comprising the degradable polymer and the active agent and the second coating solution comprising non-degradable polymer.

11. The method of claim 1, wherein removing solvent from the base layer comprises inserting the base layer and the substrate into a vacuum chamber.

12. The method of claim 1, wherein removing solvent from the base layer comprises inserting the base layer and the substrate into a vacuum chamber for a period of time greater than about 30 minutes.

13. A method of depositing a multi-layer elution control coating onto a substrate comprising:

depositing a coating solution onto the substrate to form a base layer, the coating solution comprising an active agent, a polymer, and a solvent;

storing the substrate and base layer under vacuum for a period of time greater than about 30 minutes to form a degassed base layer; and

depositing a layer of parylene on the degassed base layer.

14. A medical device comprising:

a substrate;

a base layer disposed on the substrate, the base layer comprising a polymeric matrix and an active agent, the active agent dispersed within the polymeric matrix, the active agent selected from the group consisting of peptides, proteins, antibodies, and antibody derivatives; and

a porous layer disposed directly on the base layer, the porous layer comprising parylene.

15. The medical device of claim 14, the base layer comprising a degradable polymer and a non-degradable polymer, the degradable polymer and the non-degradable polymer forming an interpenetrating network, the active agent dispersed within the degradable polymer.

16. The medical device of claim 14, the polymeric matrix comprising a hydrophobic polymer.

17. The medical device of claim 14, the polymeric matrix comprising poly-n-butylmethacrylate and polyethylene-co-vinyl acetate.

18. The medical device of claim 14, the base layer having a thickness of between about 0.5 microns and about 100 microns.

19. The medical device of claim 14, the top layer comprising poly(2-chloro-paraxylylene).

20. The medical device of claim 14 configured to elute about 0.1 μ

g/day to about 3.0 μ

g/day of the peptide for a period of time of at least about 30 days.