Reflection on the Pharmaceutical Formulation Challenges Associated with a Paediatric Investigation Plan for an Off-Patent Drug.

In Europe, the development of pediatric medicines for new patent protected products is mandatory and applicants are required to submit a Paediatric Investigation Plan (PIP) to the regulatory authorities. The process is voluntary for off-patent medicines and despite the availability of incentives, there is still a huge unmet need for the development of off-patent pediatric medicines. The aim of the EU grant funded "Labeling of Enalapril from Neonates to Adolescents" (LENA) project is to develop a new pediatric dosage form of the off-patent drug enalapril, for the treatment of heart failure in patients aged from birth to 18 years. This article provides an overview of some of the key formulation challenges that were faced during the product development programme and PIP process, including selection of dosage form and excipients, methodology for administration of the product and evaluation of patient acceptability.