ABSTRACT
This chapter describes the physiology of gastrointestinal transit and reviews what is currently known about the gastrointestinal transit of pharmaceuticals as a prelude to examining the transit of microcapsules. Microcapsules have the potential for being a versatile system for the oral delivery of drugs. Manipulation of the ingredients and manufacturing process can confer on the microcapsules specific characteristics such as the ability to control and sustain release and provide protective properties. Significant absorption of the drug took place from the colon indicating that an extended release microcapsule formulation was appropriate for this drug. The microcapsules behaved in a manner predictable from earlier work using pellets. Although the normal use of microcapsules would be to release materials, they can be employed to remove substances that are potentially toxic. Studies on the gastrointestinal transit of microcapsules are few although reasonable inferences can be made from experiments carried out with pellets.
