Drug delivery studies on electrostatically charged dry powder inhaler aerosols using a glass bead lung model

Abstract

The dry powder inhaler (DPI) is widely used for treating lung diseases such as asthma, emphysema and cystic fibrosis. Electrostatic charge has been shown to influence the deposition of inhaled particles in the lung increasing the deposition fraction for 4.5 /spl mu/m particles from 0.28 for particles under no electric field to 0.58 for particles that are negatively charged. To study the lung deposition of charged aerosols through mouth breathing, a physical lung model using a glass bead was developed. The lung model was tested by using a spinning disk aerosol generator. The deposition fraction was measured as a function of aerodynamic diameter and electrostatic charge distribution. Particles were introduced from the spinning disk aerosol generator through a throat section into a physical glass bead lung model. The throat section is an anatomical model of the larynx. An E-SPART analyzer was used to measure lung deposition as a function of the particle charge and size. The size and charge of the particles was varied from the test aerosol generator. Preliminary experimental data shows that enhanced delivery of the DPI aerosol in the lung can be achieved by controlling the electrostatic charge on the aerosol particles.