Preparation and evaluation of gastroretentive effervescent floating drug delivery system of Samchulkunbi-tang

The aim of this study was to develop a hydrophilic matrix based controlled release gastroretentive drug delivery system (GRDDS) for Samchulkunbi-tang (ST), a traditional Korean herbal medicine widely used for treatment of chronic gastritis and gastric ulcers. Effervescent floating GRDDS of ST was prepared by non-aqueous wet granulation method. Hydroxypropyl methylcellulose 2208 (100,000 cps) was used as the hydrophilic polymer, while the combination of sodium bicarbonate (NaHCO 3 ) and citric acid was used as the gas-generating agents. Formulation optimization was done by altering the amount of polymer and floating aid, keeping the tablet weight constant. Tablet properties including floating lag time (FLT), total floating time (TFT) and swelling index were measured to determine the optimized formulation. Scanning electron microscopy analysis revealed the surface morphology of the swollen tablet with concomitant gas bubbles. Optimized formulation showed satisfactory controlled in vitro drug release for more than 8 h with excellent buoyancy properties (FLT of 30 s, TFT >12 h). Therefore, the developed formulation of ST in the form of a floating tablet would provide effective gastroprotection and can be a promising approach to delivery of the drug in the upper gastrointestinal tract.