Pulmonary Drug Delivery: Pharmaceutical Chemistry and Aerosol Technology

Abstract

Delivery of drugs as aerosols to the lungs requires consideration of a number of disciplines including physical chemistry, device design and engineering, aerosol physics, and involves physiological/anatomical and pharmacological strategies. The devices that are employed to deliver drugs to the lungs may be divided into three categories: propellant-driven metered-dose inhalers (pMDIs), dry powder inhalers (DPIs), and nebulizers. Each of these systems delivers aerosols by a different principle, and the chemistry associated with the product varies significantly between them. As it becomes increasingly probable that delivery of drugs as aerosols can be achieved readily, the focus can shift to the nature of the therapeutic agent and its physical and chemical stability in the dosage forms. New chemical entities can be considered for delivery to the lungs to facilitate the control of pulmonary diseases or disease that may be treated by pulmonary drug delivery.