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
µg/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.
