Implantable reservoir for use with a medical device and system for interventional drug delivery

A surgically implantable reservoir for implantation into a patient for use in an iontophoresis system for local drug delivery through a target site of internal body tissue, the iontophoresis system including a source electrode and a counter electrode in electrical communication with the source electrode for forming a localized electric field at the target site, the reservoir comprising:

• a housing having an inner surface defining an enclosed chamber and an inlet opening and an outlet opening for flow of fluid including the drug through the chamber from the inlet opening to the outlet opening, wherein at least a portion of the housing comprises a membrane, the membrane allowing drug to pass through the membrane and into the targeted tissue when a localized electric field is applied;
• a platform extending inwardly into the chamber from the inner surface of the housing between the inlet opening and the outlet opening such that the platform and an adjacent portion of the inner surface of the housing define a trough surrounding the platform, the platform adapted for holding the source electrode;
• and
• means for securing the housing to the tissue of the target site,
• wherein fluid flow through the reservoir from the inlet opening to the outlet opening moves gas bubbles formed by electrolysis from the surface of the electrode and carries the bubbles in the trough and through the outlet opening.