A dry powder inhaler with reduced mouth-throat deposition.

A novel, compact, and highly efficient dry powder inhaler (DPI) with low mouth-throat deposition is described. The performance of this DPI was evaluated by measuring both (1) the total aerosol deposition in and distal to an idealized mouth-throat cast and (2) the fine particle fraction (FPF) using a standard Mark II Anderson impactor. Ultraviolet (UV) spectroscopy techniques were used in the aerosol deposition measurements. Two inhalation aerosol powders, namely budesonide (extracted from a Pulmicort/Turbuhaler multi-dose device, 200 microg/dose) and ciprofloxacin + lipid + lactose (in-house), were dispersed by the DPI at a steady inhalation flow rate of 60 L/min. The newly developed DPI had a total aerosol delivery distal to the mouth-throat cast of 50.5% +/- 3.04% and 69.7% +/- 1.5% for the budesonide and ciprofloxacin + lipid + lactose aerosols, respectively. This is a significant improvement over the Turbuhaler original device delivery of 34.5% +/- 5.2%, particularly considering that in vitro mouth-throat deposition dropped from 27.5% +/- 5.4% with the budesonide Turbuhaler to 11.0% +/- 3.5% with the present inhaler. The different lung deliveries from the same inhaler for the two formulations above also confirm that the overall performance of an inhaler is optimizable via powder formulations.