In vitro and in vivo bioequivalence of commercial prednisone tablets.

The purpose of the study was to examine the bioequivalence of five commercially available oral prednisone products. The in vivo study utilized 18 healthy males, each of whom was administered 20 mg of prednisone as a reference solution or as a tablet in a 6-week, six-way crossover design. Blood was collected and serum was assayed, using an HPLC procedure specific for prednisone and prednisolone. Mean pharmacokinetic parameters (t 1/2, ke, Cmax, tmax, and AUC) were determined. ANOVA was performed on the prednisone and prednisolone data (F-test, p less than 0.05) as well as Duncan's multiple range analysis. Dissolution tests were also performed on each of the five products in order to test the relationship between dissolution and bioequivalence among prednisone products. The in vitro study consisted of a standard USP dissolution test which included tablets from the same lots as the tablets used in the in vivo study. The data showed no statistical difference in any of the pharmacokinetic parameters among tableted products, subjects, or dosing periods in the study. There was also no statistical difference in the dissolution study among the five commercial tablet forms.