A method of forming an implantable medical device configured to release at least one therapeutic agent therefrom comprises disposing the therapeutic agent in a matrix affixed to a body of the implantable medical device, wherein a concentration of the at least one therapeutic agent in the matrix varies as a continuous gradient relative to a surface of the implantable medical device body, the method comprising: forming a homogeneous solution comprising a polymeric binder and a solvent evaporating the solvent in the homogeneous solution, thereby forming a matrix exposing the matrix to a solution comprising the therapeutic agent for a time sufficient to produce a partial diffusion of the therapeutic agent into the matrix such that the concentration of the therapeutic agent varies in the matrix and affixing the matrix to the implantable medical device body.
