Veterinary drug bioequivalence determination


  • P.-L. TOUTAIN,

    1. Unité Associée INRA de Physiopathologie et Toxicologie Expérimentales, Ecole Nationale Vétérinaire de Toulouse, 23 Chemin des Capelles, 31076 Toulouse, France,
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  • G. D. KORITZ

    1. Department of Veterinary Biosciences, College of Veterinary Medicine, University of Illinois, Urbana, Illinois, 61801, USA
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P. L. Toutain 23 Chemin des Capelles, 31076 Toulouse cedex, France.


A bioequivalence trial is a statistically based comparison of two formulations to demonstrate with a controlled consumer (patient) risk that two formulated drug products are interchangeable. The basic assumption underlying a bioequivalence trial is that essentially the same plasma time-course leads to essentially the same effect allowing two formulations to be interchanged. Bioequivalence is generally assessed using kinetic end points and in practice, two formulations in which bioavailability parameters (rate and extent) differ by 20% or less, with a 90% degree of confidence, are considered to be bioequivalent. In this review, the design and evaluation of bioequivalence studies are presented with special attention given to scientific issues.