Analysis of Adhesion Mechanism of DPIs in Oral Cavity

Dry powder inhalers (DPIs) have been widely used to treat respiratory diseases due to the large absorption site in a human lung. Understanding the fluid and particle deposition behaviors from the device to human respiratory system is essential to improve the efficiency of DPIs. In this study, an adhesion model of particles against liquid layer was proposed and relationship between the fluid and the particle behaviors in a pipe represented an oral cavity was analyzed by using numerical simulations. The adhesion force between particles and mucus layer in the oral cavity was calculated with the consideration of impact force, viscosity force and liquid bridge force. The numerical simulations of the particle deposition in the oral cavity revealed that the adhesion force which contributed to tension, capillary and viscosity forces, inertia of particle and particle concentration were dominated as the adhesion in the oral cavity.