THE UNUSUAL ROUTES OF ADMINISTRATION

A wide range of administration routes can be drawn on to optimise drug absorption. Though the oral route remains the favourite one for most drugs in many disease states, other routes are routinely used. Each ha s its strengths and weaknesses and needs to be selected carefully with full consideration of the drug, its target and the release pattern re quired. Advances in pharmacology and biopharmaceutics have led to exci ting developments in the ways drugs can now be administered. Optimisin g drug administration means finding answers to a number of questions. These questions include: what, how, when and where to deliver, and how to retain the drug long enough for it to be fully effective. These is sues are linked; route of administration, drug and therapeutic systems are interrelated; thus the choice of what to deliver influences how, when and where to deliver. Various definitions of 'usual/unusual' admi nistration routes are presented, depending on the factors that determi ne the fate of the active ingredients, on the delivery device, and on the therapeutic objectives to be met. The various dosage forms designe d for these routes, and the administration strategies developed to ach ieve the desired effects are described.