Development of a high efficiency dry powder inhaler: effects of capsule chamber design and inhaler surface modifications.
OBJECTIVE
The objective of this study was to explore the performance of a high efficiency dry powder inhaler (DPI) intended for excipient enhanced growth (EEG) aerosol delivery based on changes to the capsule orientation and surface modifications of the capsule and device.


METHODS
DPIs were constructed by combining newly designed capsule chambers (CC) with a previously developed three-dimensional (3D) rod array for particle deagglomeration and a previously optimized EEG formulation. The new CCs oriented the capsule perpendicular to the incoming airflow and were analyzed for different air inlets at a constant pressure drop across the device. Modifications to the inhaler and capsule surfaces included use of metal dispersion rods and surface coatings. Aerosolization performance of the new DPIs was evaluated and compared with commercial devices.


RESULTS
The proposed capsule orientation and motion pattern increased capsule vibrational frequency and reduced the aerosol MMAD compared with commercial/modified DPIs. The use of metal rods in the 3D array further improved inhaler performance. Coating the inhaler and capsule with PTFE significantly increased emitted dose (ED) from the optimized DPI.


CONCLUSIONS
High efficiency performance is achieved for EEG delivery with the optimized DPI device and formulation combination producing an aerosol with MMAD < 1.5 μm, FPF<5 μm/ED > 90%, and ED > 80%.
Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, 401 West Main Street, P.O. Box 843015, Richmond, Virginia, 23284-3015, USA.
Srinivas R B
SR
Behara
Dale R
DR
Farkas
Michael
M
Hindle
P Worth
PW
Longest
D000336:Aerosols / Q000737:chemistry*; D002214:Capsules / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical / Q000379:methods; D016503:Drug Delivery Systems / Q000379:methods; D058995:Dry Powder Inhalers / Q000379:methods; D005079:Excipients / Q000737:chemistry; D010316:Particle Size; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D011208:Powders / Q000737:chemistry*
D000336:Aerosols; D002214:Capsules; D005079:Excipients; D004364:Pharmaceutical Preparations; D011208:Powders