Population PK modelling as an alternative route to bioequivalence

Demonstratingbioequivalence (BE) is important for the development of lower cost genericproducts, and also for approving post-submission manufacturing changes.However, for many complex parenteral products, BE demonstration can be verychallenging. For example, long-acting injectable products are engineered tohave an extended release over several weeks or months, but this also means thata traditional BE study can take many months or years to perform. Here, we summarisehow population PK modelling, which captures differences in PK profiles due topopulation variation, could be used explore hundreds of virtual formulations,and thus determine a range of products that are bioequivalent after bothmultiple and single dosing. This provides a guide for formulation developmentbut also opens alternative, more streamlined routes to BE assessment.