Comparison of pharmacokinetics in beagle dogs of nimesulide bilayer tablets with dispersible tablets

The purpose of this study was to compare the in vitro release and the in vivo pharmacokinetics of bilayer tablets with the conventional dispersible tablets of nimesulide. The tablets were administered to beagle dogs and the plasma levels of nimesulide were determined by high-performance liquid chromatography-MS/MS. The pharmacokinetic parameters were calculated using a noncompartmental model. The bilayer tablets showed a biphasic in vitro release pattern with initial burst release and sustained release following the quasi-Fickian diffusion-based release mechanism. The Cmax, tmax, mean residence time (MRT), and area under the curve from 0 to 36 h were 10.8 ± 4.2 μg/mL, 2.3 ± 1.0 h, 6.7 ± 2.1 h, 81.5 ± 26.7 μg·h/mL for the bilayer tablets and 14.8 ± 5.8 μg/mL, 2.7 ± 0.8 h, 5.6 ± 0.9 h, 95.4 ± 44.2 μg·h/mL for the dispersible tablets. Compared with the dispersible tablets, the bilayer tablets have lower Cmax, similar tmax, and longer MRT. The aforementioned pharmacokinetic parameters, especially the MRT demo...