Excipients in Neonatal Medicinal Products: Never Prescribed, Commonly Administered.

To attain effective and safe pharmacotherapy, formulations in (pre)term neonates should enable extensive dose flexibility. During product development and subsequent authorization and clinical use of such formulations, there is also a need for informed decisions on excipient exposure: in addition to the need to improve the knowledge on active compounds, there is a similar need to improve the knowledge on excipients in neonates. Excipients are added to formulations as co-solvent, surfactant, preservative, colorant and/or sweetener as vehicle(s) to result in a suitable (e.g. taste, shelf life, stability) product. Progress has been made in the awareness, knowledge and access to this knowledge on the clinical pharmacology of excipients in neonates. This is thanks to different initiatives focussing on epidemiological data, excipient pharmacokinetics, or building datasets to create this knowledge. We highlight the Safe Excipient Exposure in Neonates and Small Children (SEEN) and propylene glycol project to illustrate the feasibility to build knowledge, and discuss the methods applied and problems observed during these studies. The information generated in these and other studies (European Study on Neonatal Exposure to Excipients, ESNEE) should be integrated in repositories like the Safety and Toxicity of Excipients for Paediatrics (STEP) to facilitate access to all stakeholders. This merged knowledge should have impact and assist in improving the quality of risk assessment and decision making during drug development, applying a risk-benefit framework (explicit justification of excipients, plan product development early and engage all stakeholders, data sharing and modeling, challenges related to new excipients, context sensitive risk-benefit analysis).