Introduction
In recent years, increased interest in the scientifi c basis of
aerosol therapy has given rise to a growth in technology
that makes use of the inherent advantages of the inhaled
route of drug administration for the treatment of both
pulmonary and non-pulmonary diseases. A key advantage
of this route is that it enables delivery of low doses of an
aerosolised drug to its site of action for a localised eff ect
(ie, directly to airway surfaces), which leads to a rapid
clinical response with few systemic side-eff ects,
particularly for aerosolised β-agonist therapy.1 Drug
delivery to the systemic circulation via the distal lung
results in rapid absorption of the drug from this large
surface area. However, when inhaled drugs are
administered for eff ects on the airway (eg, inhaled
corticosteroids), systemic absorption of the drug can give
rise to unwanted side-eff ects.