Formulation and characterization of Tween 80/cholestherol niosomes modified with tri-n-octylmethylammonium chloride (TOMAC) for carboxylic acids entrapment

The effects of different formulations on the physicochemical properties of unloaded and carboxylic acid-loaded niosomes are studied. Citric acid and lactic acid were the model carboxylic acids employed. The niosomes were prepared by ultrasonication of different formulations in a phosphate buffer at pH 2 and 7 containing Tween 80 (polyoxyethylene (20) sorbitan monooleate) and cholesterol as the vesicle forming agents. This study examines the effect of tri-n-octylmethylammonium chloride (TOMAC) on the degree of Tween 80 aggregation, acid entrapment efficiency, hydrodynamic size, and zeta potential of the formulated niosomes. Carboxylic acid entrapment efficiency may be explained in terms of interaction within the solubilization sites of the niosomes. TOMAC addition at pH 7 increased both the Tween 80 aggregation and citric acid entrapment efficiencies, but its effect on lactic acid entrapment was lower.