The formulation team at Impax needed a user-friendly software tool to support developing IVIVC models. IVIVC is a predictive mathematical tool that describes the relationship between an in vitro property of a drug dosage form and an in vivo pharmacokinetic response. This biopharmaceutical tool is a surrogate for in vivo bioavailability and can be used to demonstrate virtual bioequivalence and support attaining regulatory biowaivers. For the past six years, the Impax generics team has been using Certara’s IVIVC Toolkit for Phoenix WinNonlin on a daily basis to support formulation optimization. The IVIVC Toolkit’s intuitive graphical user interface is easy to learn and doesn’t require prior coding knowledge; it is a solution that the entire Impax formulation team can use.