In Vivo Evaluation of a Gastroretentive Drug Delivery System Based on Enteric-Coated Floating Tablets

Floating dosage forms are supposed to exhibit an enhanced gastric residence time. Their development is challenging as the prediction of the retention potential in humans based on in vitro studies and animal models is difficult.
A strategy to determine the stomach residence time of a floating dosage form with an inherently low density in human without using imaging techniques was explored in a self-experiment.
Floating tablets and non-floating controls were prepared containing caffeine as a model drug. The compacts had a pH-dependent entericcoating to assess their stomach residence time. Since caffeine is rapidly absorbed in the gastrointestinal tract, the prolonged gastric retention of tablets can be demonstrated by a delayed systemic exposure. Caffeine and paraxanthine were determined in capillary blood by liquid chromatography coupled to tandem mass spectrometry.
An increase in caffeine and paraxanthine blood levels was observed in human volunteers after 90 to 180 min for the non-floating controls. For the floating tablets, no elevated blood concentrations were found in two out of three participants during 8 h of sample collection.
The results demonstrate the technical feasibility of the proposed clinical study protocol. Follow-up clinical trials will be needed to confirm the preliminary data on stomach residence time of our floating dosage form.