Single-dose Fasting Bioequivalence Assessment of Erythromycin Stearate Tablets in Man

The bioequivalence of film-coated erythromycin stearate tablets produced by five different manufacturers was evaluated in a balanced incomplete block design involving the five formulations given to 30 fasted subjects over a 3-week study period. Serum levels of erythromycin activity were determined microbiologically. Statistical analysis of variance was performed on the observed bioavailability parameters: maximum serum concentration (Cmax), time to maximum serum concentration (Tmax), and area under the serum concentration-time curve (AUC). There was no statistical difference between formulations for the Tmax parameter. Formulation differences were found, however, based on the analysis of variance of the Cmax and AUC parameters. Two products, although not significantly different from one another, showed significantly greater Cmax and AUC values than the other three products.