Chandrasekaran and Kandasamy: Solid Oral Flexible Formulation Platform for Paediatrics and Geriatrics The oral route of drug administration is mostly preferred by paediatric and geriatric patients. Patient non-compliance due to poor taste and swallowing problems are major issues in paediatric and geriatric drug therapy. Lack of age-appropriate formulations, inadequate labelling instructions, non-compatible and non-palatable medicines are the main reasons for medication errors in paediatric patients. This review mainly highlights major issues of paediatric and geriatric drug therapy and provides the design of oral flexible formulations as an alternative formulation design for age appropriate formulation development. Development of solid oral flexible formulations as an alternative to existing marketed formulations such as conventional tablets, orally disintegrating tablets, chewable and dispersible tablets for paediatric and geriatrics patients is described. Details about drug properties, excipient selection and taste masking approaches were described. The need for bioavailability and bioequivalence studies for flexible formulations also described. Development of flexible formulations as an alternative to marketed different formulations of the same drug would reduce the cost of the formulation for patients particularly developing countries where accessibility to various types of formulations is less. Flexible tablet formulations can be conveniently used by the patients as orally swallowable, orally disintegrating, chewable and as dispersible tablets. Sprinkle formulations such as pellets, granules packed in capsules or sachets can be conveniently used by paediatric and geriatric patients. Properly designed and developed flexible formulations for new chemical entities and off-patent drugs are need of the hour to provide better treatment to varying age groups of paediatrics and geriatrics.