SCINTIGRAPHIC ASSESSMENT OF DRUG-DELIVERY FROM THE ULTRAHALER DRY POWDER INHALER

A new dry powder inhaler, the Ultrahaler, has been developed to delive r nedocromil sodium for the prophylaxis of asthma, This study was perf ormed to compare the lung deposition of nedocromil sodium inhaled from the Ultrahaler at two different inhaled flow rates with that from a p ressurised metered dose inhaler (MDI). A scintigraphic study was condu cted in 12 healthy volunteers, On each study day, volunteers received a single 4.2 mg dose of nedocromil sodium from the Ultrahaler, using e ither an optimal (fast) inhaled Bow rate or a suboptimal (slow) inhale d Bow rate, or two doses of 2 mg nedocromil sodium from an MDI using a n optimal (slow) inhaled flow rate, Used optimally, the Ultrahaler dep osited significantly more (p < 0.05) of the metered dose in the lungs than either the Ultrahaler used suboptimally or the MDI used optimally [mean (SD) lung deposition values of 13.3 (4.8)%, 9.8 (3.5)%, and 7.5 (2.9)%, respectively], Oropharyngeal deposition averaged over 80% of the dose for all three treatment regimens, This scintigraphic study de monstrated in vivo proof of concept for the Ultrahaler dry powder inha ler, and provided quantitative data on the relationship in lung deposi tion between the Ultrahaler and MDI which differed from that predicted by the in vitro fine particle fraction.