Bioavailability of griseofulvin plain tablets in stomach-emptying controlled rabbits and the correlation with bioavailability in humans
Aoyagi, N.; Ogata, H.; Kaniwa, N.; Ejima, A.
Journal of Pharmacobio-Dynamics 7(9): 630-640
Bioavailability after giving oral doses of 62.5 mg griseofulvin tablets having different dissolution rates to stomach-emptying controlled rabbits, was estimated and compared with that in humans receiving 125 mg dose of the same griseofulvin preparations. The relative differences in Cmax and AUC infinity between the product with the highest availability and others tended to be greater in rabbits than in humans. The in vivo parameters correlated well between the two species. However, power analysis indicated a larger variability of Cmax in rabbits than in other species (dogs, minipigs and humans). Water volume (5 and 50 ml) coadministered with the drug did not significantly influence the bioavailability. The rabbits which were not given food after oral dosing with griseofulvin exhibited a lower Cmax than those which were fed immediately after dosing. The bioavailability of an ultramicronized formulation in rabbits was higher after the postprandial dose than after the preprandial dose. Food intake just after the drug administration seems to be an important factor for controlling the passage rate of the drug through the gastrointestinal tract in stomach-emptying controlled rabbits.