A scintigraphic study to evaluate the deposition patterns of a novel anti-asthma drug inhaled from the Cyclohaler dry powder inhaler

A scintigraphic study was performed, in 10 healthy volunteers, to determine the deposition patterns of a novel anti-asthma drug, LAS 31025, inhaled from a dry powder inhaler, the Cyclohaler. In addition, plasma concentrations of drug following inhalation were determined to investigate their relationship to the deposition patterns. Increasing doses of LAS 31025 were inhaled by the volunteers on four separate study days; 2.25, 4.5, 9.0 and 18.0 mg. The average lung deposition values corresponding to these dose levels were 19.1, 20.9, 19.5 and 17.5%, respectively. Deposition patterns within the lungs were similar on each of the four study days, with slightly more of the dose deposited in the central and intermediate regions compared to the peripheral lung region. The scintigraphic data were supported by the pharmacokinetic measurements as there was an increase in the maximum plasma concentration and area under the concentration-time curve corresponding to the increased doses of LAS 31025 on successive study days. (C) 1997 Elsevier Science B.V.