Medicines given to neonates need to be adapted for this age-group. This includes both dosage and pharmaceutical form. Dosage, because clearance is lower in neonates, but also because there is extensive between-individual variability in clearance in the first months of life. Pharmaceutical forms, because formulations need to account for dosage variability, but also to the clinical characteristics of neonates.

The need for an appropriate balance between dose, volume, drug manipulations and dose flexibility in neonates calls for dedicated, tailored formulations.

Besides the active compound (s), drug formulations contain solvents and additives, usually referred as ‘excipients’, needed as co-solvents, surfactants (general term for compounds that improve absorption, unrelated to the lung surfactant administered for hyaline membrane disease), preservatives, colourants and/or sweeteners. These excipients are added e.g. to ensure stability over a given shelf life, to improve palatability or to facilitate solubility or to bulk up formulations that otherwise contain highly potent active ingredients and are referred to as preservatives, sweeteners, fillers and solvents, coating materials or colouring agents. Consequently, during the development of these formulations, there is a need to quantify and limit excipient exposure based on the currently available knowledge on their safety or toxicity. Furthermore, focused studies on the clinical pharmacology of excipients in neonates should be conducted, and its feasibility will be illustrated by the propylene glycol research project. Finally, until tailored vials and formulations become available, compounding practices for drug formulations in neonates should be evaluated to guarantee the correct dosing, product stability and safety.