Rabeprazole sodium is a proton pump inhibitor widely used as an antiulcer drug in gastric ulcers and various gastro-esophaegal diseases. Rabeprazole sodium is absorbed in the gastrointestinal tract and because it is unstable under acidic conditions, enteric delivery systems are required. The aim of the present work was to study the effect of formulation variables e.g., sodium alginate concentration (X1), calcium chloride concentration(X2), on drug entrapment efficiency (Y1), in-vitro release profiles (Y2) and particle size (Y3) of multi-particulates system of Rabeprazole sodium. Experiments were designed according to 32 factorial design. Alginate beads were formulated using ionotropic gelation method after preparation the beads were coated with Eudragit RS 100. Developed formulations were characterized and evaluated on the basis of particle size, entrapment efficiency and drug release studies. The formulation variables were optimized by response surface methodology (RSM)
