Patent ID: 8449901

Claim:
An implantable medical device configured to release at least one therapeutic agent therefrom, the device comprising: an implantable body having a mural surface and a luminal surface; and a matrix affixed to the implantable body on said luminal surface, the matrix containing the at least one therapeutic agent therein, wherein the matrix is formed with an outer surface and an implantable body contacting surface such that the concentration of the therapeutic agent in the matrix varies as a gradient relative to the said surfaces of the matrix; wherein the concentration of the therapeutic agent in the matrix is higher at said luminal surface of the implantable body than at said mural surface of the implantable body; wherein the implantable body is substantially cylindrical and contains a plurality of struts therein, and the matrix is disposed in a plurality of holes passing through at least some of said struts in the implantable body, and the matrix is coated with a barrier layer at the luminal surface; and wherein the therapeutic agent has a maximum concentration substantially adjacent to the barrier layer and a minimum concentration substantially adjacent to said mural surface of the implantable body.