Drug products contain an active pharmaceutical ingredient (API) and other inactive ingredients, such as excipients, diluents, lubricants, and binders. The purpose of the inactive ingredients is to optimise the drug’s performance, for example by modifying drug release or facilitating absorption. The API together with these ingredients make up the drug formulation.
During drug development, all drug products are formulated to particular dosage forms – such as oral tablets, capsules, injections, topical and inhaled – in order to be delivered effectively to the patient. Formulation development therefore depends on the dosage form, as will the technology required and the challenges facing research and development (R&D) scientists.