Dissolution-Permeation Systems in Biopharmaceutical Research: A Graphical Review on the Current State-of-the-Art

Drug dissolution/release assessment is one of the most important tests for oral dosage forms and it is crucial in drug formulation development. Due to the shift of the paradigm in pharmaceutical research and development pipelines to the dominance of poorly soluble drugs (BCS classes II/IV), the compendial pharmacopeial dissolution testing approaches primarily designed for highly soluble drugs (BCS classes I/III) often lack universal applicability and are not sufficient to predict drug absorption in vivo. New enabling formulations together with increasing importance of drug permeability testing, and artificial digestion is being used to address issues with the development of poorly soluble drug formulations. This review demonstrates the current state-of-the-art, by describing the advances in the evolution of approaches for drug dissolution and permeation testing systems. It emphasises available equipment and its role in addressing the challenges posed by poorly soluble drugs. In addition, in consideration of the developability classification system, a testing equipment that is currently available was proposed for specific drug classes.