Investigation of water vapour sorption mechanism of starch-based pharmaceutical excipients.

•Particle size of starch has no effect on the water absorption-desorption behaviour.•Level of pregelatinisation in starch samples has changed the rate of water absorption.•DVS can be used to investigate the effect of the level of pregelatinisation on moisture absorption-desorption behaviour.•Monolayer formation of moisture in partially pregelatinised starch samples is much faster compared to fully pregelatinised sample.