Each ZOLBI 20mg capsule contains 20 mg of omeprazole in the form of enteric-coated pellets.
Each ZOLBI 40mg capsule contains 40 mg of omeprazole in the form of enteric-coated pellets.
Mechanism of Action
Omeprazole belongs to a class of antisecretory compounds, the substituted benzimidazoles, that suppress gastric acid secretion by specific inhibition of the H+/K+ ATPase enzyme system at the secretory surface of the gastric parietal cell. Because this enzyme system is regarded as the acid (proton) pump within the gastric mucosa, omeprazole has been characterized as a gastric acid-pump inhibitor, in that it blocks the final step of acid production. This effect is dose-related and leads to inhibition of both basal and stimulated acid secretion irrespective of the stimulus.
ZOLBI capsules contain an enteric-coated pellet formulation of omeprazole (because omeprazole is acid-labile), so that absorption of omeprazole begins only after the pellets leave the stomach. Absorption is rapid, with peak plasma levels of omeprazole occurring within 0.5 to 3.5 hours. The systemic bioavailability of omeprazole from a single oral dose of ZOLBI is approximately 35%. After repeated once-daily administration, the bioavailability increases to about 60%. In healthy subjects the plasma half-life is 0.5 to 1 hour. Concomitant intake of food has no influence on the bioavailability.
Protein binding is approximately 95%.
Omeprazole is extensively metabolized by the cytochrome P450 (CYP) enzyme system.
About 80% of the metabolites are excreted in the urine and the rest in the faeces. The two main urinary metabolites are hydroxy-omeprazole and the corresponding carboxylic acid.
The elimination rate of omeprazole was somewhat decreased in the elderly, and bioavailability was increased.
The pharmacokinetics of omeprazole have been investigated in pediatric patients 2 to 16 years of age.
Dose reduction, particularly where maintenance of healing of erosive esophagitis is indicated, for the hepatically impaired should be considered.
Because urinary excretion is a primary route of excretion of omeprazole metabolites, their elimination slowed in proportion to the decreased creatinine clearance. No dose reduction is necessary in patients with renal impairment.
Dose reduction, particularly where maintenance of healing of erosive esophagitis is indicated, for Asian subjects should be considered.