Evaluating the Potential of Ellipsoidal Particles for Inhalation Therapy in Comparison to Spherical Particles

Inhalation therapy using dry powder inhalers play an important role in treatment of human respiratory diseases. In targeted drug delivery, it is necessary to deliver a right amount of drug to the right place for reducing the side effects, which requires a deep understanding of the behavior of inhaled particles in the human respiratory system. The purpose of present study is to evaluate the potential of ellipsoidal particles for targeting drug delivery in a realistic model of tracheobronchial airway extends from oral cavity to the fourth generation. Ellipsoidal particles with fixed minor axis of 3.6 µm and different aspect ratio in the range of 1 to 10 are injected to the airway model at steady state flow rate using the discrete phase model in Fluent software. This simulation includes drag and gravity force acting on ellipsoidal particles. The deposition patterns of ellipsoidal particles are compared to spherical particles. The results showed that flow rate has a direct effect on particle transport and consequently on deposition pattern of both ellipsoidal and spherical particles, and most of the deposition occurs in the mouth-throat. In addition, the deposition of ellipsoidal particles in the mouth-throat region reduced as the aspect ratio increased. In conclusion, ellipsoidal particles showed more flexibility for targeting drug delivery compared to spherical particles.