A SCINTIGRAPHIC STUDY TO EVALUATE THE DEPOSITION PATTERNS OF A NOVEL ANTIASTHMA DRUG INHALED FROM THE CYCLOHALER DRY POWDER INHALER

A scintigraphic study was performed, in 10 healthy volunteers, to dete rmine 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 invest igate their relationship to the deposition patterns. Increasing doses of LAS 31025 were inhaled by the volunteers on four separate study day s; 2.25, 4.5, 9.0 and 18.0 mg. The average lung deposition values corr esponding to these dose levels were 19.1, 20.9, 19.5 and 17.5%, respec tively. Deposition patterns within the lungs were similar on each of t he four study days, with slightly more of the dose deposited in the ce ntral and intermediate regions compared to the peripheral lung region. The scintigraphic data were supported by the pharmacokinetic measurem ents 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 Scienc e B.V.