Editing Bioequivalence (section)

== Bioequivalence  ==
In determining bioequivalence between two products such as a commercially available Branded product and a potential to-be-marketed [[Generic drug|Generic product]], [[pharmacokinetic]] studies are conducted whereby each of the preparations are administered in a [[cross-over study]] (sometimes parallel study, when a cross-over study is not feasible) to volunteer subjects, generally healthy individuals but occasionally in patients. [[Serum (blood)|Serum/plasma]] samples are obtained at prescribed times and assayed for parent drug (or occasionally [[metabolite]]) concentration. Occasionally, blood concentration levels are neither feasible or possible to compare the two products (e.g. inhaled [[corticosteroids]]), then [[pharmacodynamic]] endpoints rather than pharmacokinetic endpoints (see below) are used for comparison. For a pharmacokinetic comparison, the plasma concentration data are used to assess key pharmacokinetic parameters such as area under the curve (AUC), peak concentration (''C''<sub>max</sub>), time to peak concentration (''t''<sub>max</sub>), and absorption lag time (''t''<sub>lag</sub>). Testing should be conducted at several different doses, especially when the drug displays non-linear pharmacokinetics.

In addition to data from bioequivalence studies, other data may need to be submitted to meet [[Regulation of therapeutic goods|regulatory requirements]] for bioequivalence. Such evidence may include:

* analytical method validation
* ''in vitro-in vivo'' correlation studies ([[IVIVC]])