Drug delivery performance of the mometasone furoate dry powder inhaler

The mometasone furoate dry powder inhaler (MF-DPI) is a multiple-dose, breath-actuated inhaler that uses agglomerates of micronized MF and lactose. lit vitro analyses evaluated dose uniformity, variability, and particle size distribution of the MF-DPI. Tests of first, middle, and end doses from 10 inhalers each of the 200-mug MF/inhalation and 400-mug MF/inhalation dose sizes found that delivered doses (doses emitted from the inhaler) ranged from 91% to 112% of claimed doses for all tested DPIs. The mean MF doses delivered at 28.3 L/min were 100% and 94% of the doses delivered at 60 L/min for the 200-mug and 400-mug dose sizes, respectively; the relative standard deviation of doses was less than or equal to6.1% within this range of inhalation rates. At a flow rate of 60 L/min, the mean delivered doses, compared to claimed doses for inspiration times of 1-3 sec, were 102-104% for the 200-mug dose size and 98.8-102% for the 400-mug dose size. The mean cumulative fraction of dose delivered at 60 L/min for 2 sec which consisted of particles of <6.5 mum, in diameter was 39.9% ( +/-2.5 SD; n = 9) for the 200-mug dose size and 35.6% ( +/-3.4 SD; n = 9) for the 400-mug dose size. All MF-DPI inhalers tested were well within U.S. and European compendial. standards and regulatory guidelines for dose uniformity. An appropriate and reproducible fraction of the delivered dose was within the optimal particle size range for therapeutic effectiveness.