Sustained release drug delivery to the lungs: an option for the future.

There are potential therapeutic advantages in administering drugs as sustained release formulations to the lungs. This presents the challenges of controlling drug release from particles within the lung environment while overcoming the natural clearance mechanisms. Approaches being adopted involve the administration of particles of small aerodynamic diameter to the alveoli and avoiding phagocytosis by high phospholipid content or large geometric particle size. Studies in animals have demonstrated the utility of such formulations.