Article ID Journal Published Year Pages File Type
2481413 European Journal of Pharmaceutical Sciences 2010 8 Pages PDF
Abstract

This study aims to investigate the role of impact angles on the de-agglomeration performance of powders for inhalation. Agglomerates of a model drug mannitol were impacted at customized impaction throats containing two angles (15–75° and 45–45°) or a single angle (15°, 45° and 90°) using various air flow rates. The mass fraction of fine particles <5 μm in the aerosol (FPFLoaded) was measured by a liquid impinger coupled to a laser diffractometer. Results showed that for the two-angle throats, there existed an optimal angle (45°) and air flow (120 l min−1) for the FPFLoaded, resulting from a balance between improved de-agglomeration and enhanced throat deposition with increasing air flow. When the throat contained two equal angles of 45°, most powder deposition occurred at the first angle, indicating that the first angle was likely to cause major de-agglomeration, while the second angle might act as a facilitator for further break-up, but the deposition was minimum as the fragment sizes and velocity at the second impaction were smaller. This hypothesis was supported by further studies using single-angle throats and numerical simulation (DEM–CFD). These findings imply the potential importance of using angular design features for multiple impactions to improve DPI performance.

Related Topics
Health Sciences Pharmacology, Toxicology and Pharmaceutical Science Drug Discovery
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