Composition for coating an implantable prosthesis

The present invention provides a method of forming a coating onto a surface of an implantable prosthesis, such as an expandable stent, a synthetic vascular graft, or some other implantable device. A composition comprising a therapeutic substance and a fluid in which the therapeutic substance has limited solubility, such that the therapeutic substance is suspended as particles in the composition, is applied to a surface of the prosthesis. The fluid is removed from the prosthesis to form a coating. A coating for a prosthesis produced in accordance with the method is also provided. A suspension stabilizer may be employed to reduce flocculation of the therapeutic substance within the composition. The composition may additionally include a polymer, such as, but not limited to, a bioabsorbable polymer, a biomolecule, or a biostable polymer. A polymeric primer layer may be applied to the surface of the prosthesis prior to the application of the therapeutic composition. In addition, a polymeric topcoat disposed on at least a portion of the therapeutic composition on the surface of the prosthesis may be applied.