Investigation of Electrostatic Behavior of Dry Powder-Inhaled Model Formulations

The accumulation of electrostatic charge on drug particles and excipient powders arising from interparticulate collisions or contacts with other surfaces can lead to agglomeration and adhesion problems during the manufacturing process, filling, and delivery of dry powder inhaler (DPI) formulations. The objective of the study was to investigate the role of triboelectrification to better understand the influence of electrostatic charge on the performance of DPIs with 2 capsule-based dimensionally similar devices constructed with different materials. In addition, strategies to reduce electrostatic charge build up during the manufacturing process, and the processes involved in this phenomenon were investigated. Electrostatic charge measurements showed that there was a significant difference in electrostatic charge generated between tested formulations and devices. This affects particle detachment from carrier and thus significantly impacts aerosol performance. Conditioning fluticasone DPI capsules at defined temperature and humidity conditions reduced electrostatic charges acquired during manufacturing. Conditioning salmeterol DPI capsules at same conditions seemed disadvantageous for their aerosol performance because of increasing capillary forces and solid bridge formation caused by water absorption. Knowledge and understanding of the role of electrostatic forces in influencing DPI formulation performance was increased by these studies.