Rabeprazole Sodium (E-Reb) is an antiulcerant drug in the class of Proton Pump Inhibitors. Rabeprazole sodium is a substituted benzimidazole which suppresses gastric acid secretion by inhibiting the gastric H+/K+-ATPase enzyme at the secretory surface of the gastric parietal cell. It blocks the final step of gastric acid secretion. It is an enteric coated tablet, because of its coated formulation it is highly stable in the stomach and because of higher pKa value of rabeprazole sodium, it provides faster onset of action. After oral administration of 20 mg, rabeprazole is absorbed and can be detected in plasma by 1 hour. The effects of food on the absorption of rabeprazole have not been evaluated. Rabeprazole is 96.3% bound to human plasma proteins. It is primarily metabolized in the liver by Cytochrome P-450 3A (Sulphone metabolite) and 2C19 (Desmethyl Rabeprazole). Following a single 20 mg oral dose of rabeprazole, approximately 90% of the drug is eliminated in the urine. The remainder of the dose is excreted in the feaces.