Respiratory diseases such as asthma, chronic obstructive pulmonarydisease (COPD), and idiopathic pulmonary fibrosis are among the most serious and widespread healthcare challenges facing thedeveloped world, accounting for more than 400,000 deaths in the EuropeanUnion, equivalent to 8% of the total mortality figure (1). Such figures highlight the growing need for innovative and effectivetreatments. Pulmonary drug delivery is receiving increased attention asa non-invasive means for local treatment of a wide range of major lung diseases; this route of administration, however, posesadditional challenges for medicinal and formulationchemists.