Delayed total release two pulse gastrointestinal drug delivery system

Abstract

A two pulse gastrointestinal delivery system is provided. The system comprises a desired agent in combination with a swellable core material, the core being surrounded by an inner coat of a water-insoluble or relatively water-insoluble coating material in which particulate water-insoluble material is embedded. The inner coat is additionally surrounded by an outer coat that contains additional amounts of the desired agent. When the delivery device enters the gastrointestinal tract, the outer coat releases the desired agent contained therein and disintegrates, exposing the inner coat. The particulate matter in the inner coat takes up liquid, thus forming channels interconnecting the drug-containing core with the outside of the delivery device. Through these channels liquid enters the core which then swells to the point at which the inner coat is broken. When the integrity of the inner coat is destroyed, the core then disintegrates, immediately releasing all or most of the drug at a specific site. By controlling parameters in the device, such as the core material, carrier material in the coating, and particulate matter, the location of release of both pulses of the drug can be carefully controlled. The invention is also directed to a method of using the device for the treatment of disease by the release of drugs in the gastrointestinal tract in a location- and time-dependent manner.