Bioavailability of different brands of griseofulvin tablets and its correlation to dissolution data

A bioavailability study was carried out in man on five brands of griseofulvin tablets. Urinary excretion of free and total 6-demethylgriseofulvin was monitored for 24 h after single 125 mg doses. The bioavailability information, deduced from metabolite excretion data, pointed to inter-brand differences in rate but not extent of griseofulvin absorption. Correlations were sought between in vivo data and previousely determined dissolution parameters using a two phase system. Based on the correlation coefficients obtained, dissolution data proved predictive of absorption rates of griseofulvin tablets. Meaningful correlation between dissolution rate and extent of griseofulvin absorption was not observed.