Paediatric biopharmaceutics classification system: current status and future decisions.

Biopharmaceutical methods are routinely used in the design of medicines to predict in vivo absorption and hence guide the development of new products. Differences in anatomy and physiology of paediatric patients require adaptation of existing biopharmaceutical methods to ensure that in vivo predictions are relevant for this population. The biopharmaceutics classification system is a tool used in drug development to guide formulation selection and manufacture from early clinical studies through to product launch. The applicability of the biopharmaceutics system to paediatric product development has yet to be explored; this note brings together some key issues in direct extrapolation from adults into paediatric populations.