Physicochemical properties and release behavior of Span 60/Tween 60 niosomes as vehicle for α-Tocopherol delivery

In this study, Niosomes, as vehicles for alpha-Tocopherol were formulated applying film hydration method to improve the availability and stability of alpha-Toc. Parameters affecting encapsulation efficiency (EE), mean size, polydispersity index and zeta potential were investigated, along with the different molar ratio of Span 60/Tween 60, presence or absence of cholesterol (Chol) and dicetyl phosphate (DCP). Then, the morphology, stability and in vitro release of selected formulation were studied. The results showed that alpha-Toc loaded niosomes exhibited a small mean size (106.8 +/- 0.5 to 190 +/- 0.2 nm), narrow size distribution and high EE (83.22 +/- 0.65 to 99.07 +/- 0.15). A significant change in the EE and vesicle size in different niosomal formulations was observed. The optimum preparation condition of alpha-Toc-loaded niosome was as follows: 3:1 mol ratio of Span 60:Tween 60,4 mg/mL of alpha-Toc and 25:12.5:2.5 M ratio of Surfactant:Chol:DCP. Having increased the HLB, the EE and stability of the niosomes decreased. The DCP and Chol improved the physicochemical properties of niosomes. In vitro release of the selected formulation showed an initial burst effect and was followed by a slow drug release. In general, the film hydration method can be used as a suitable and commercial technique for the production of alpha-Toc-loaded niosomes with high EE. (C) 2017 Elsevier Ltd. All rights reserved.