This document discusses various aspects of in vitro drug product performance testing and evaluation, including dissolution profile comparisons, meeting dissolution requirements, problems in dissolution testing, and in vitro-in vivo correlation (IVIVC). It describes model-independent and model-dependent approaches to comparing dissolution profiles using difference factor (f1) and similarity factor (f2). It also discusses the four levels of IVIVC (A, B, C, and multiple C) and their applications and limitations. Finally, it covers considerations for drug product stability and design.