Quantification of Imidapril in Human Plasma Using the LC-MS/MS Method for Bioequivalence and Pharmacokinetic Studies

Abstract

We developed the LC-MS/MS method through a comparison of the pharmacokinetic characteristics of imidapril to assess the bioequivalence of two types of imidapril in 31 normal Korean subjects. Blood samples were collected at 13 time points for 12 h after dosing and detected by LC-MS/MS in the range of 0.2-100 ng/mL with LLOQ of 0.2 ng/mL. Pharmacokinetic parameters analyzed from the plasma samples and data from the reference and test drugs in the plasma were represented such as AUC(0-t) (142.31 vs 131.95 ng.h/mL), AUC(0-infinity) (143.85 vs 133.72 ng.h/mL), C-max(33.28 vs 30.46 ng/mL), T-max(2.0 vs 1.9 h), half-life(1.6 vs 1.6 h), extrapolation (1.35 vs 1.46%), and Ke (0.46 vs 0.45 h(-1)). Pharmacokinetic parameters with a 90% confidence interval (CI) were 0.873-1.084 for AUC(0-t) and 0.863-1.149 for C-max. Pharmacokinetic parameters with 90% CI were included within the bioequivalence range of 80-125% of the KFDA guidelines. Therefore, the two imidapril types were found to be bioequivalent during the fasting state in normal subjects.