Multi-layered coatings and methods for controlling elution of active agents
View Patent ↗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.
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 concentration of the solvent effective to produce a coating with a desired elution rate;
removing solvent from the base layer to obtain the selected concentration of solvent; and
depositing a layer of parylene on the base layer while the solvent is out-gassing from the base layer to produce a porous parylene 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 8 , 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.