Potential of a cyclone prototype spacer to improve in vitro dry powder delivery.
OBJECTIVE
Low inspiratory force in patients with lung disease is associated with poor deagglomeration and high throat deposition when using dry powder inhalers (DPIs). The potential of two reverse flow cyclone prototypes as spacers for commercial carrier-based DPIs was investigated.


METHODS
Cyclohaler®, Accuhaler® and Easyhaler® were tested with and without the spacers between 30 and 60 Lmin−1. Deposition of particles in the next generation impactor and within the devices was determined by high performance liquid chromatography.


RESULTS
Reduced induction port deposition of the emitted particles from the cyclones was observed due to the high retention of the drug within the spacers (e.g. salbutamol sulphate (SS): 67.89 ± 6.51% at 30 Lmin−1 in Cheng 1). Fine particle fractions of aerosol as emitted from the cyclones were substantially higher than the DPIs alone. Moreover, the aerodynamic diameters of particles emitted from the cyclones were halved compared to the DPIs alone (e.g. SS from the Cyclohaler® at 4 kPa: 1.08 ± 0.05 μm vs. 3.00 ± 0.12 μm, with and without Cheng 2, respectively) and unaltered with increased flow rates.


CONCLUSIONS
This work has shown the potential of employing a cyclone spacer for commercial carrier-based DPIs to improve inhaled drug delivery.
Irene
I
Parisini
Sean J
SJ
Cheng
Digby D
DD
Symons
Darragh
D
Murnane
D002851:Chromatography, High Pressure Liquid; D016503:Drug Delivery Systems; D066298:In Vitro Techniques; D010316:Particle Size; D011208:Powders
D011208:Powders