The active ingredient Omeprazole in Benzim is a substituted benzimidazole, 5-methoxy-2-[[(4-methoxy-3, 5-dimethyl-2-pyridinyl) methyl] sulfinyl]-1H-benzimidazole.
MECHANISM OF ACTION
Omeprazole belongs to a new class of anti-secretory compound benzimidazole. It inhibits the secretion of gastric acid by irreversibly blocking the enzyme system of hydrogen/potassium adenosine triphosphatase (H+/K+ATPase), the proton pump of the gastric parietal cell.

PHARMACOKINETICS
Absorption: Absorption is rapid, with peak plasma levels of Omeprazole occurring within 0.5 to 3.5 hours. Absolute bioavailability is about 30-40% at doses of 20-40 mg, due in large part to presystemic metabolism. Half-life is 0.5 to 1 hour and the total body clearance is 500-600 mL/min. Distribution: The apparent volume of distribution in healthy subjects is approximately 0.3L/kg. The plasma protein binding of Omeprazole is about 95%.
Metabolism & Excretion: Omeprazole is almost completely metabolized in the liver. The majority of the dose (about 77%) is eliminated in the urine and the remainder is recoverable in the feces. The total plasma clearance is 0.3 to 0.6L/min. The volume of distribution is slightly decreased, while the plasma half-life of Omeprazole is increased.
INDICATIONS
Omeprazole (Benzim) is indicated for the treatment of Gastro-oesophageal reflux disease, Peptic ulcer disease, Treatment and prophylaxis of NSAID-associated ulceration, Zollinger-Ellison syndrome and Prophylaxis of acid aspiration.