Evaluation of the Intelisite capsule to deliver theophylline and frusemidetablets to the small intestine and colon

The objective of the research was to establish the capability of the Inteli site capsule to deliver the probe drugs, theophylline and frusemide, in the form of split immediate release (IR) tablets, to the small intestine and c olon. The two probe drugs were administered together in an open, random, th ree-way crossover study in eight healthy volunteers, comparing absorption f ollowing Intelisite: delivery in the small bowel and colon to conventional IR dosing. Gamma scintigraphy was employed to monitor the gastrointestinal transit and activation of the Intelisite capsule. Standard pharmacokinetic parameters, and the percentage remaining in the capsules post defecation we re determined. The Intelisite capsule was well tolerated in human volunteer s and successfully activated on 15/16 occasions. Pharmacoscintigraphy showe d internal marker release from the Intelisite capsule to be similar to 10-f old faster in the small intestine than in the colon. Theophylline and fruse mide were both well absorbed following Intelisite activation in the small i ntestine, whereas complete colonic absorption was only observed in 1/7 subj ects for theophylline, and 0/7 subjects for frusemide. The probe drugs were successfully delivered in particulate form from the Intelisite capsule in the small intestine and produced expected pharmacokinetic profiles. However drug release in the colon was incomplete and variable possibly due to: low water content, poor mixing, and a high loading dose. (C) 2001 Published by Elsevier Science B.V.