Fabrication of micro and nano-particles via electrohydrodynamic atomization process for pharmaceutical applications

In the present work, Electrohydrodynamic Atomization (EHDA), or electrospray, was employed to produce biodegradable polymeric micro and nano-particles in a new generation ofencapsulation chamber. The effects of different parameters including solution flow rate, nitrogen flow rate, nozzle, and ring voltage on the particle collection efficiency and residual amount oforganic solvent in collected particles were investigated systematically. A Computational Fluid Dynamics (CFD) model was also developed in this study to simulate the fluid and particle dynamics in an EHDA encapsulation chamber thereby providing a means of predicting particlecollection efficiencies at various operating conditions. It was found that nitrogen flow rate, solution flow rate and voltage difference between the nozzle and ring can significantly affect the particle collection efficiency of the EHDA process. Electric field and electric potential profiles inthe chamber were significantly affected by the combined voltages of the nozzle and ring. In general, a good qualitative agreement in particle collection efficiencies from experiments and simulations was obtained. The computational model developed in this study provided a means of understanding the various processes involved in particle fabrication using the EHDA methodology.

Keywords:

Electrohydrodynamic atomization , pharmaceuticals , particle collection efficiency , residual solvent , Computational Fluid Dynamics , Lagrangian approach