2005 Volume 51 Issue 3 Pages 308-316
The objective of this study was to estimate the pharmacokinetics of the newly developed once-daily acemetacin sustained-release tablets compared with those of the commercial acemetacin sustained-release capsules. Ten male healthy Chinese volunteers were included in the study. The administration schedule was a randomized crossover design. Each volunteer received 90 mg of the tablet or the capsule in the single-dose study, and each received 90 mg of the tablet or the capsule once daily for 6 consecutive days in the multiple-dose study. The areas under the concentration-time curve (AUC0-24 hr), maximal concentrations of indomethacin (Cmax), time to reach peak concentration (Tmax), and elimination half-life (T1/2) values of indomethacin (an active metabolite of acemetacin) were 6.72 ± 0.99 μg.hr/ml, 0.82 ± 0.08 μg/ml, 4.2 ± 0.6, and 10.1 ± 4.2 hr, respectively. The steady-state AUC120-144 hr and steady-state maximal concentration of the tablets increased to 10.33 ± 1.06 μg.hr/ml and 1.14 ± 0.10 μg/ml, respectively. The pharmackinetic parameters (AUC0-24 hr, Cmax, T1/2, and mean residence time) for two formulations were not significantly different but the average Tmax of the tablets was delayed by 1 hr compared with that of the capsules (4.2 ± 0.6 vs. 3.2 ± 0.6 hr, p < 0.05). The mean relative bioavailability of the tablets was 97.9 ± 14.8% compared with that of the capsules. It could be concluded that the pharmacokinetic parameters of the newly developed sustained-release tablets are similar to those of the sustained-release capsules, excluding the Tmax value. A significant correlation was obtained between the in vivo mean absorption rate and the in vitro mean dissolution rate for the newly developed sustained tablets.