Patent attributes
A coated implantable medical device 10 includes a structure 12 adapted for introduction into the vascular system, esophagus, trachea, colon, biliary tract, or urinary tract; at least one coating layer 16 posited on one surface of the structure; and at least one layer 18 of a bioactive material posited on at least a portion of the coating layer 16, wherein the coating layer 16 provides for the controlled release of the bioactive material from the coating layer. In addition, at least one porous layer 20 can be posited over the bioactive material layer 18, wherein the porous layer includes a polymer and provides for the controlled release of the bioactive material therethrough. Preferably, the structure 12 is a coronary stent. The porous layer 20 includes a polymer applied preferably by vapor or plasma deposition and provides for a controlled release of the bioactive material. It is particularly preferred that the polymer is a polyamide, parylene or a parylene derivative, which is deposited without solvents, heat or catalysts, and merely by condensation of a monomer vapor.