The application of new bioavailability parameters in the bioequivalence testing of antimicrobial agents

Two new bioavailability parameters were recently suggested [Koeleman et al. 1991] to define (i) the time that the concentration in the blood stays above a defined minimum effective concentration, te and (ii) the onset of the effect, to. In addition to conventional bioequivalence parameters, the new bioavailabilty parameters (to and te) were calculated in this study and statistically compared for penicillin, chloroquine, oxytetracycline, amoxycillin and flucloxacillin from available bioequivalence data. For oxytetracycline, flucloxacillin and amoxycillin, the conventional bioavailability parameters indicated partial equivalence whereas using the te and to parameters, more realistic indications of the possible extent of the performance of a drug from dosage forms were obtained than with the conventional bioequivalence parameters. The new parameters gave additional information for a better evaluation of the performance of a drug from a dosage form.