According to an aspect of the present invention, implantable or insertable medical devices are provided which contain the following: (a) substrate having one or more depressions that contain at least one therapeutic agent and (b) a porous membrane disposed over the substrate and the one or more depressions,...http://www.google.com.au/patents/US20090157166?utm_source=gb-gplus-sharePatent US20090157166 - Medical Devices Having Porous Component For Controlled Diffusion
