Formulation optimization of gastroretentive drug delivery system for allopurinol using experimental design.

Objectives: The objective of the study was to develop gastroretentive dosage form (GRDF) for allopurinol (ALP) using combined approaches of mucoadhesion and floating systems. GRDF was systematically optimized using 3(2)-full factorial design.

Methods: Concentrations of sodium carboxymethyl cellulose (X1) and concentration of polyoxyethylene oxide WSR 303 (X2) were selected as independent variables, whereas gastroretentive parameters like total floating time (TFT) (Y1), mucoadhesive force (MF) (Y2), time required for 10% drug release (Y3) and time required for 80% drug release (Y4) were selected as dependent variables in development of robust GRDF of ALP.