Bioavailability of griseofulvin from plain tablets in Göttingen minipigs and the correlation with bioavailability in humans

Intravenous administration of 125 mg of griseofulvin to Gottingen minipigs showed biexponential elimination of the drug from plasma, in which the half lives of the initial and terminal phases were 0.2-0.6 h and 4.3-6.6 h, respectively. The bioavailability of four griseofulvin tablets used in a human bioavailability study was investigated in the pigs and compared with the human results. The differences of Cmax and AUC between the standard product and the others were smaller in the pig than in humans, however, the correlations of Cmax and AUC between humans and minipigs were high for the four products. The differences of Tmax among the products were small, and the Tmax of the standard product was large in the pigs compared with that in humans. In addition, delayed onset of drug absorption was observed in some of the pigs. The findings suggest slow gastric emptying of the drug in the pigs. The statistically small powers for the in vivo parameters observed in the pig, seem to indicate variable absorptxon of the drug in the animal.