In-flight electro-neutralisation electrospray for pulmonary drug delivery

In-flight electro-neutralisation electrospray for pulmonary drug delivery

Pulmonary drug delivery does not only provide non-invasive therapy for local lung diseases but also remarkably
enhances systemic absorption of therapeutics owing to the tremendous surface area of the lung and fast transport
of active molecules across the respiratory epithelia. In comparison to traditional delivery systems, electrohydrodynamic atomisation (EHDA) is superior in terms of size and production rate control but the high surface
charges of resulting particles prohibit its use in drug delivery. To overcome this challenge, we developed an inflight electro-neutralisation electrospray (IFENE) method which enables the generation of mists of particles in
respirable size range with little to no charge. Our approach uses low-frequency alternating current (AC) to
produce charge-neutralised sprays with initial velocity due to oppositely charged droplets combination. Experiments and simulations with pure liquid as the working solution were conducted to reveal the underlying
mechanism. The applied frequency is found to be the main factor that influences spray stability and formation.
Poly (vinylidene fluoride) (PVDF) and PVDF with curcumin solution were electrosprayed via IFENE, producing
sprays of organic particles with controlled sizes and neutralised charges. The capability of coupling particle
generation in the respirable size range (below 5 μm) and charge reduction (under 400 femtoamperes), along with
its simple setup makes IFENE a promising platform technology in inhalation drug delivery.