Particle self-neutralization for highly efficient deep lung drug delivery via bipolar electrohydrodynamic atomization

Electrohydrodynamic atomization (EHDA) technology is showing great promise as a more flexible and controllable alternative to conventional nebulizers and inhalers for inhalation-based drug delivery. However, its application is limited by low flow rates and the excessive surface charge on particles, which restricts deep lung deposition. In this study, we introduce a novel bipolar EHDA device, designed for pulmonary drug delivery. This device uses two oppositely charged nozzles to generate self-neutralizing micro/nano particles ideal for inhalation. Experimental and computational investigations confirm the formation of a stable dual-cone jet and efficient neutral particle production at a flow rate of 10 ml/h, which, for the first time in the literature, is comparable with current commercial nebulizers. The polymeric particles exhibit mean aerodynamic diameters 2.65 μm, suitable for deep lung deposition, minimal residual charge, and consistent performance across repeated trials. Furthermore, curcumin-loaded polymeric particles show favorable characteristics including high drug encapsulation, sustained release, and biocompatibility. Deposition testing using an Andersen cascade impactor demonstrated excellent targeting of the deep lung region with minimal drug loss. These results confirm the potential of bipolar EHDA as a compact, high-throughput, and non-invasive solution for pulmonary drug delivery.