| abstract |
The present invention is directed to novel implantable or insertable medical devices that provide release of a therapeutic agent. According to a first aspect of the present invention, a therapeutic-agent-releasing medical device is provided, which comprises: (a) an implantable or insertable medical device; (b) a release layer disposed over at least a portion of the implantable or insertable medical device, and (c) a therapeutic agent. The release layer regulates the rate of release of the therapeutic agent from the medical device upon implantation or insertion of the device into a patient. The release layer comprises (i) a first polymer comprising one or more polymer chains that form one or more polymer phase domains when the first polymer is in a pure solid-state form; and (ii) a second polymer comprising two or more polymer chains that form two or more phase domains when the second polymer is in a pure solid-state form. The first and second polymers are preferably selected such that at least one polymer chain in the second polymer is compatible with at least one polymer chain in the first polymer. The present invention is also directed to methods of forming the above implantable or insertable medical devices, methods of administering a therapeutic agent to a patient using such devices, and methods of modulating the release of therapeutic agents from implantable or insertable medical devices. |