Evaluating Okra Gum in a Floating Tablet Formulation as a Novel Drug Delivery System

Okra gum has desirable properties that make it a suitable polymer candidate that can substitute more expensive synthetic polymers in gastroretentive drug formulation. In this study, the buoyancy properties of promethazine tablets containing okra gum and gas-generating agents sodium carbonate and bicarbonate were evaluated to determine if a new floating drug delivery system for promethazine hydrochloride is feasible. The physico-mechanical properties as well as the swelling indices of the tablets were assessed using standard methods. The in-vitro buoyancy and fluid uptake kinetics of the gum in promethazine hydrochloride tablets were also evaluated. The results showed that the tablets were generally elegant, non-friable, possessed acceptable hardness, and were able to float, while the swelling index showed that the gum was able to imbibe fluid and swell appreciably. The swelling kinetics of the formulations based on the Vergnaud model showed a non-concentration dependent diffusion-controlled mechanism with no burst effect.