Bioavailability of inhaled fluticasone propionate via chambers/masks in young children

Abstract

We determined lung bioavailability of a fluticasone propionate (FP) pressurised metred-dose inhaler (Flovent® HFA; GlaxoSmithKline, Research Triangle Park, NC, USA) administered via AeroChamber Plus® (Monaghan Medical, Plattsburgh, NY, USA) with Facemask and Babyhaler®(GlaxoSmithKline) valved holding chambers (VHCs) using a population pharmacokinetic approach. Children from 1 to <4 yrs of age with stable asthma but a clinical need for inhaled corticosteroid therapy were administered 88 mg FP hydrofluoroalkane (2 x 44 μg) twice daily delivered through the two devices in an open-label, randomised crossover manner for 8 days each. Patients were randomised to one of three sparse sampling schedules for blood collection throughout the 12-h dosing interval on the 8th day of each treatment for pharmacokinetic analysis. The area under the FP plasma concentration - time curve (AUC) was determined for each regimen. 17 children completed the study. The population mean AUC following FP with AeroChamber Plus® with Facemask was 97.45 pg·h·mL -1 (95% CI 85.49-113.32 pg·h·mL -1) and with Babyhaler®was 51.55 pg·h·mL -1 (95% CI 34.45-64.46 pg·h·mL -1). The relative bioavailability (Babyhaler®/AeroChamber Plus®) was 0.53 (95% CI 0.30-0.75). Clinically significant differences in lung bioavailability were observed between the devices. VHCs are not interchangeable, as differences in drug delivery to the lung may occur. A population pharmacokinetic approach can be used to determine lung bioavailability of FP. Copyright©ERS 2012.