d) Osmotic effect
Addition of hypertonic salt solution to the suspension of niosomes
brings about reduction in vesicle diameter with concomitant water
efflux, probably due to pumping out of vesicle content (Baillie et al.,
1985). In hypotonic salt solution, there is a initial slow release with
slight swelling of vesicles probably due to inhibition of eluting fluid
from vesicle, followed by faster release, due to mechanical loosening
of vesicles under osmotic stress.