An evaluation of the systemic bioavailability of mometasone furoate (MF) after oral inhalation from a MF/formoterol fumarate metered-dose inhaler versus an MF dry-powder inhaler in healthy subjects.

PURPOSE: This randomized, open-label, multiple-dose, two-period, crossover study compared the systemic bioavailability of mometasone furoate (MF) administered from a metered-dose inhaler containing MF and formoterol fumarate (F) (MF/F-MDI) versus MF administered from a single-ingredient dry-powder inhaler (MF-DPI).

METHODS: Healthy, non-smoking adults, 18-65 years with body mass index 18-29 kg/m(2) (N = 12) received MF 800 µg/F 20 µg via MF/F-MDI or MF 800 µg via MF-DPI twice daily for 5 days separated by a 7-day period. MF pharmacokinetics (AUC(0-12 hour) , Cmax , and Tmax ) were measured at Day 1 and 5 after each treatment. Safety and tolerability were assessed.

RESULTS: Systemic exposure to MF based on AUC(0-12 hour) was ∼25% lower following MDI versus DPI administration. The Day 5 geometric mean ratio (MDI/DPI) estimates (90% confidence intervals [CI]) for AUC(0-12 hour) and Cmax were 0.747 (0.61, 0.91) and 0.606 (0.49, 0.75), respectively. The accumulation index (R) value for MF was higher following MDI (3.81-fold) versus DPI administration (2.34-fold) indicative of prolonged absorption. The most common adverse events were tremor, headache, and catheter site pain.

CONCLUSIONS: Systemic exposure to MF was lower following multiple-dose MF/F-MDI administration versus MF-DPI administration. The magnitude of this difference is not considered to be clinically important. MF/F-MDI was safe and generally well tolerated.