On the assessment of variability in bioavailability/bioequivalence studies

A procedure is proposed for the assessment of bioequivalence of variabilities between two formulations in bioavailability/bioequivalence studies. This procedure is essentially a two one-sided Pitman-Morgan’s tests procedure which is based on the correlation between crossover differences and subject totals. The nonparametric version of the proposed test is also discussed. A dataset of AUC from a 2×2 crossover bioequivalence trial is presented to illustrate the proposed procedures.