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

A method for local delivery of drug molecules by iontophoresis through a target site of internal body tissue of a patient, the drug delivery method comprising the steps of:

• providing a source electrode;
• providing a counter electrode in electrical communication with the source electrode, the counter electrode being configured to cooperate with the source electrode to form a localized electric field at the target site;
• implanting in the patient a reservoir adapted to be secured to the target site, the reservoir comprising
• a housing having an inner surface defining an enclosed chamber having an inlet opening and an outlet opening for fluid flow through the chamber, and at least a portion of the housing comprising a membrane,
• a platform disposed in the housing and extending inwardly into the chamber from the inner surface of the housing 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,
• delivering a fluid cargo including the drug to the inlet opening of the housing, the fluid cargo capable of being delivered through the tissue of the target site when exposed to the localized electric field formed between the source electrode and the counter electrode,
• wherein the membrane allows drug to pass through the membrane and into the targeted tissue when a localized electric field is applied, and
• wherein cargo flow through the reservoir from the inlet opening to the outlet opening moves gas bubbles formed by electrolysis from a surface of the source electrode and carries the bubbles in the trough and through the outlet opening.