ABSTRACT
PURPOSE: In this work, a novel powder dispersion add-on device, the AOS (Axial Oscillating Sphere), was studied in conjunction with commercially available DPI devices to improve the powder dispersion. METHODS: An ordered mixture of formoterol fumarate and lactose was selected. We studied in two laboratories located at different altitudes the dispensing and dispersion of the drug at different flow rates, paying particular attention to a number of metrics of Fine Particle Dose (FPD). RESULTS: Two novel findings emerged from the data collected. First, the aerosol quality, measured as fine particle dose, can be increased by adding the accessory promoting the dispersion and de-aggregation of the formulation. The second finding was that, albeit the emitted dose was independent of altitude, the drug/lactose carrier DPI aerosolizing performance changed with the altitude of testing. In particular, fine particle dose depended on both altitude and device configuration. The RS01 inhaler without the AOS accessory used at higher altitude gave the lowest FPD values. By combining the AOS accessory with the DPI, however, the performance dependence on altitude/atmospheric pressure was essentially removed. CONCLUSIONS: Increasing inhaler performance can be achieved using an add-on accessory that enhances aerosol dispersion and minimizes flow rate dependency.
