Bioequivalence accomplishments, ongoing initiatives, and remaining challenges

Although bioequivalence (BE) concepts date back to the late 1960s, there has been a steady evolution in the tools applied to the assessment of product comparability. Despite these advancements, we continue to face a multitude of unresolved challenges. Several of these challenges are unique to veterinary medicine due to issues such as multiple species approvals, unique dosage forms (e.g., intramammary infusion and medicated premixes), physiological challenges (e.g., limitations in blood volume and stress reactions), and the need to evaluate product equivalence for products intended to release drug over a duration of months. Thus, while in some instances, we can adopt advancements implemented by our human health counterparts but in other situations, we need to pioneer our own method for resolving these challenges. The purpose of this manuscript is to provide an update on recent advances, achievements, and ongoing initiatives associated with the assessment of product BE in veterinary medicine. This review reflects the highlights of a presentation given at the 2012 meeting of the European Association for Veterinary Pharmacology and Toxicology.