Method of coating stents

A process for coating implantable medical devices comprising:

• (a) applying a primer coating on the implantable medical devices, including the application of a parylene layer and annealing the parylene layer to reduce autoxidation initiators;
• (b) preparing a basecoat solution comprising polymers and a therapeutic agent and applying the basecoat solution to the implantable medical devices coated with parylene, the basecoat solution being prepared with and applied utilizing a process to reduce the presence and exposure of the basecoat solution to oxygen, the implantable medical device with basecoat is dried with recirculating air for at least 30 minutes at a relative humidity of about 30 to about 55 percent;
• (c) preparing a topcoat solution comprising at least one polymer and applying the topcoat solution to the implantable medical devices coated with the basecoat solution, the topcoat solution being prepared with and applied utilizing a process to reduce the presence and exposure of the topcoat solution to oxygen;
• (d) applying toluene that has the potential to redissolve the coating components and alter the surface finish and the dissolution properties of the therapeutic agent, and drying the implantable medical device with topcoat and toluene with recirculating air for at least 30 minutes at a relative humidity of about 30 to about 55 percent;
• (e) reducing the solvent content thereby raising the glass transition temperature of the therapeutic agent and creating a coating morphology to protect the therapeutic agent from autoxidation;
• and
• (f) finally processing the implantable medical devices, including inspecting, packaging and sterilizing the coated medical devices, the final processing including protecting the therapeutic agent from autoxidation, reducing the presence of and exposure of all materials to radicals and reducing the presence of and exposure of all materials to oxygen.