Dry powder inhalers depend on the release of fine active pharmaceutical ingredient (API) particles deposited on larger carrier particles. The work established that API particles in the near-wall regions of the inhaler are primarily dispersed due to the deceleration of the carrier particle during wall impact. The dispersion ratio increases with increasing impact velocity and impact angle. The results will assist in the design of carrier-based API formulations since the dispersion performance can be closely approximated using a cumulative Weibull distribution function that is governed by the ratio of overall impact energy and adhesion energy.
- discrete element method
- dry powder inhalation