Production of chitosan pellets by extrusion/spheronization.

Chitosan pellets were successfully prepared using the extrusion/spheronization technology. Microcrystalline cellulose was used as additive in concentrations from 70 to 0%. The powder mixtures were extruded using water and diluted acetic acid solution in different powder to liquid ratios. The effects on bead formation using water and different acetic acid concentrations and solution quantities were analysed. Also, the morphological and mechanical characteristics of the obtained beads were investigated. With demineralized water as granulation fluid, pellets with a maximum of 50% (m/m) of chitosan could be produced. The mass fraction of chitosan within the pellets could be increased to 100% by using diluted acetic acid for the granulation step.