Novel electrohydrodynamic preparation of porous chitosan particles for drug delivery.

Uniform spherical chitosan particles of size 10 microm diameter. In this study, by reducing surface tension of a high viscosity chitosan suspension, it was found that smaller diameter particles could be prepared. Chitosan solutions were electrosprayed in the stable cone-jet mode to systematically study the relationship between particle diameter, viscosity and surface tension. Increasing viscosity resulted in larger diameter particles with a broad size distribution, but decreasing surface tension had the opposite effect. Results show that a chitosan solution having a viscosity of approximately 80 mPa s can be used to prepare chitosan particles of diameter approximately 2.5 microm which on drying reduced to particles of 500 nm.