Tuesday, 6 December 2011: 13:00 - 13:15
Isla Mujeres (Cancún Center)
Robert Berger
,
Device Development, Merck Research Laboratories, Summit, NJ
Steve Li
,
Merck Research Laboratories, Kenilworth, NJ
Heribert Staudinger, MD
,
Merck Research Laboratories, Merck Sharp & Dohme Corp, Kenilworth, NJ
Background: Regional lung deposition of inhaled particles depends on particle size as well as inspiratory flow rate and other factors. Inhaled particles of aerodynamic size around 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 via a dry powder inhaler showed mean peak inspiratory flow rates (PIFR) 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). We report particle size findings from an in vitro study analyzing the mass median aerodynamic diameter (MMAD) of MF.
Methods: Twelve inhalers each of the 110 and 220 μg/inhalation 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 110 µg/inhalation strength and 1 inhalation from the 220 µg/inhalation strength, thereby providing similar particle masses.
Results: The average MMAD of the MF 110 μg strength for beginning and ending inhalations (n=24) was 2.0 μm (range, 1.9-2.1 μm), while the MF 220 μg strength for beginning and ending inhalations (n=24) was 2.2 μm (range, 2.0-2.4 μm).
Conclusions: 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 particle size of MF is optimal (~2 μm) for efficient alveolar deposition when administered via dry powder inhaler.
