Absolute bioavailability and pharmacokinetics of the angiotensin II receptor antagonist fimasartan in healthy subjects

The present study was conducted to determine the absolute bioavailability of fimasartan (FMS; Kanarb((R))) after the single oral administration of a 60-mg tablet or a single 30-mg intravenous (IV) infusion. This investigation was a randomized, single-dose, open-labeled, two-way crossover study of 16 healthy Korean male subjects. The subjects were divided into two groups (n=8) and each received either the oral or IV formulation followed by one-week washout period. The C-max (ng/ml) and AUC(infinity) (h.ng/ml) following oral and IV administration were 62.4 +/- 48.6 and 291.1 +/- 121.7; and 683.3 +/- 104.3 and 782.3 +/- 112.7 (mean +/- SD), respectively. The T-max (h) were 3.0h (range: 0.5-5.0h) and 1.0h (range: 0.8-1.0h) in the test and reference groups, respectively. The terminal elimination half-lives (t(1/2), h) were similar (5.8 and 5.5h, respectively) indicating that the route of administration did not influence the absorption or elimination of FMS. The systemic clearance (CL, L/h) and the volume of distribution at steady-state (Vd(ss), L) were 331.3 +/- 444.5L/h and 403.3 +/- 710.4L following oral administration and 39.1 +/- 5.3L/h and 42.4 +/- 25.5L following IV administration. The absolute bioavailability of the FMS tablet was 18.6%.