A comparison of the gastric retention of alginate containing tablet formulations with and without the inclusion of excipient calcium ions

Abstract Gamma scintigraphy has been used to monitor the gastric residence of tabletted alginate preparations. It was found that a new formulation of Gaviscon tablets containing calcium carbonate as an excipient formed a raft which persisted in the stomach for approx. 2 h. In contrast, the raft formed from Gastrocote tablets readily dispersed and emptied with the food contents of the stomach. In vitro experiments illustrated a greater raft breaking strength for the ‘new’ Gaviscon tablets but raft thickness and time of raft formation were similar for both preparations. The study suggests that new Gaviscon tablets may display superior anti-reflux activity and that the ability to form a strong persistent raft may be influenced by the ion content of the formulation.