Age-adapted drug formulations are a challenge in drug development. This paper describes the special requirements of paediatric and geriatric patients, and new ideas to solve the most prominent problems in the application of drugs to these patients. Most requirements are very similar in each subpopulation, but there are also some particularities. In neonates and infants, the immaturity of enzymes may determine the pharmacokinetics of the excipients, which must be carefully selected. Pharmacokinetics in the elderly are strongly influenced by co-morbidity, multiple-drug use or reduced organ functions. The drug handling and the readability of the product information are key issues in both subpopulations. Children and the elderly show difficulties in swallowing solid dosage forms for oral use. In both patient groups, small sized particulates or liquid dosage forms are superior to classic tablets or capsules. The main problem with using liquids is the palatability of the solution, especially when considering that taste sensation differs age-dependently and interindividually. Recent technological developments such as the dose sipping technology, promise improvements. The new EU legislation for the development of new paediatric drugs may also stimulate the research into drug delivery for the elderly.