Lansoprazole

Lansoprazole is a substituted benzimidazole prodrug with selective and irreversible proton pump inhibitor activity. Lansoprazole prodrug is converted to an active sulfonamide derivative in the acidic environment of the gastric parietal cell; the sulfonamide derivative binds to the gastric proton pump h+k+ atpase and forms a stable disulfide bond with the sulfhydryl group near the potassium-binding site on the luminal side, resulting in inactivation of the atpase and a reduction in gastric acid secretion. This agent does not have anticholinergic or histamine h2 -receptor antagonistic properties. A 2, 2 2-trifluoroethoxypyridyl deri- vative of timoprazole that is used in therapy of stomach ulcers & zollinger-ellison syndrome. The drug inhibits h (+) –k (+)-exchanging atpase which is found in gastric parietal cells. Lansoprazole is a racemic mixture of (r)- and (s)-isomers.