TY - JOUR T1 - The aerodynamic particle size of mometasone furoate 100 μg and 200 μg dry powder formulations JF - European Respiratory Journal JO - Eur Respir J VL - 38 IS - Suppl 55 SP - p3983 AU - Robert Berger AU - Steven Li AU - Heribert Staudinger Y1 - 2011/09/01 UR - http://erj.ersjournals.com/content/38/Suppl_55/p3983.abstract N2 - Background: Regional lung deposition of inhaled particles depends on aerodynamic particle size, as well as inspiratory flow rate and other factors. Inhaled particles of aerodynamic sizes of approximately 2 μm have been found to deposit most efficiently in the alveolar region across a broad range of inspiratory flow rates. In vivo studies of mometasone furoate (MF) delivered by the Twisthaler® showed mean peak inspiratory flow rates at satisfactory levels in adult/adolescent patients aged ≥12 years (69 L/min), children aged 9–12 years (>60 L/min), and children aged 5–8 years (>50 L/min).Objective: We report aerodynamic particle size findings from an in vitro study analyzing the mass median aerodynamic diameter (MMAD) of MF.Methods: Twelve inhalers each of the 100 and 200 μg strengths were tested in vitro at the beginning and end of unit lives at a 60 L/min flow rate. Aerosolized MF was collected by cascade impaction for 2 inhalations from the 100 μg strength and 1 inhalation from the 200 μg strength, thereby providing similar particle masses.Results: The average MMAD of the 100 μg strength for beginning and ending inhalations (n=24) was 2.0 μm (range, 1.9–2.1 μm), while the 200 μg strength for beginning and ending inhalations (n=24) was 2.2 μm (range, 2.0–2.4 μm).Conclusion: Average MMAD values of MF for both strengths measured in vitro at a clinically relevant flow rate, together with in vivo particle-size efficiency deposition models, suggest that the aerodynamic particle size of MF is optimal (∼2 μm) for efficient alveolar deposition when administered via the Twisthaler®. ER -