Disposition kinetics of omeprazole in healthy female volunteers in Pakistan

Abstract

Omeprazole (OMP) a proton pump inhibitor is widely used to suppress gastric acid secretions of parietal cells of stomach and metabolized predominantly by CYP2C19. The objective of the present study was to investigate the pharmacokinetics and dosage regimen of OMP, after its single oral administration in eight healthy adult female subjects. Blood samples were collected at different time intervals after oral administration and their pH was measured. Plasma concentration of OMP was determined by high performance liquid chromatography (HPLC) system equipped with UVvisible Detector. The concentration versus time data was used to compute the pharmacokinetic parameters with the help of computer software programme MW/PHRAM APO version 3.02.Peak plasma concentration was (Cmax) 0.38±0.04 µg/ml achieved at 2.07±0.22 hrs. The elimination half-life (t1/2β) was1.82±0.42 hrs. Volume of distribution (Vd) in the present study was 0.40±0.07 l/kg with total body clearance (ClB) 0.19±0.02 l/hr/kg and area under the curve (AUC) 1.89 ±0.23 µg.hr/ml.The pharmacokinetic properties which are different from the literature after oral administration of 20 mg OMP in eight healthy female volunteers may be due to the variations of environment and genetic variation between Pakistan and drug manufacturing of foreign countries.