Perspectives on the Biopharmacy of Inhalation Aerosols

Abstract

Particle size distribution is an important parameter with respect to the deposition behaviour of inhaled aerosols and must be viewed as a dynamic variable changing during the passage through the humid and warm environment of the respiratory tract. It is suggested that studies of particle growth rate and the formulation factors affecting it are necessary for a rational design of inhalation aerosols. Absorption and metabolism of drugs by the lung are also briefly reviewed and compared to the situation following gastro-intestinal administration. Possible advantages offered by the inhalation route are discussed.