Surfactant and cholesterol are
dissolved in chloroform. The solvent is then
evaporated under reduced pressure to get a
thin film on the wall of the round bottom
flask. The film is hydrated with citric acid (pH
4.0) by vortex mixing. The multilamellar
vesicles are frozen and thawed 3 times and
later sonicated. To this niosomal suspension,
aqueous solution containing 10 mg/ml of
drug is added and vortexed. The pH of the
sample is then raised to 7.0-7.2 with 1M
disodium phosphate. This mixture is later
heated at 60°C for 10 minutes to give
niosomes.