Pharmacokinetics of lansoprazole injection in peptic ulcer and healthy volunteers

The pharmacokinetics of lansoprazole after a single intravenous dose of 30 mg was determined in 10 healthy volunteers and 10 peptic ulcers patients. In this work, a liquid-liquid extraction and enrichment method with RP-HPLC determination route was taken with high sensitivity and low limit detection of 5 ng/mL. The concentration-time curves in the two groups were best fitted to a two-compartment model, but their main kinetic parameters were remarkably different between healthy and ulcers volunteers. The mean maximum plasma concentration (C_max ) and area under the curve (AUC_0t ) were increased from 975.8 ng/mL to 1298.7 ng/mL and from 1439 ng·h/mL to 2301 ng·h/mL, respectively, and peak time (t_max ) decreased from 0.36 h to 0.26 h. Meanwhile, the half life (t_1/2 ) prolonged from 2.25 h to 2.91 h and the clearance (CL) reduced from 20.04 L/h to 13.96 L/h. That variability of lansoprazole pharmakinetic parameter indicates that ulcers have significant effect on its metabolic process. Colegio de Farmacéuticos de la Provincia de Buenos Aires