Niosome Entrapment

Niosomes as nonionic surfactant-based vesicles are capable to entrap both hydrophilic and lipophilic compounds in the aqueous phases between the bilayers and inside the surfactant bilayer, respectively (Devaraj et al., 2002). This unique character along with low-cost and high storage stability has led to their wide usages in cosmetic, pharma, bio, and food industries (Marianecci et al., 2014). Conventional ethanol injection (CEI) technique is one of the most important methods to prepare niosomes because it is a simple and easily scaled approach without use of any possibly dangerous material (Pham, Jaafar-Maalej, Charcosset, & Fessi, 2012). The production of Fe microcapsules using niosomes prepared by CEI to enrich yogurt has been recently reported by Gutierrez et al. (2016). These researchers distinctly produced two aqueous and organic phases. The suitable levels of three common surfactants (Span 80, Peceol, and Plurol Oleique), and a membrane stabilizer agent (1-dodecanol) in absolute ethanol were dissolved to form the organic phase. Components of FeSO₄, vitamin C, di-Na phosphate, and citric acid in distilled water were dissolved to create the aqueous phase. In the next step, the developed organic phase with a flow rate of 130mL/h at 40°C was injected into the water phase using a syringe pump. Prior to the contact of two produced phases, a number of spontaneous niosomes were formed. However, there were high quantities of niosomes with very fine particle size and narrow distribution after blending and stirring at 5000 rpm. Finally, the spherical microcapsules (0.35—0.82 pm, EE = 72—84%) by removing ethanol in a rotary evaporator were stored to formulate the yogurts. Evaluating the Fe-bioavailability by determining its oxidation rate and EE under the simulated gastrointestinal conditions showed that the best formulation for niosomal systems was use of Peceol surfactant and 1-dodecanol which could significantly improve the quality attributes of yogurt compared with the control (Gutierrez et al., 2016). Wagner, Spoth, Kourkoutis, and Rizvi (2016) have also studied concurrent encapsulation of hydrophilic vitamin D₃ and lipophilic FeSO₄ supplements into niosomes using a new supercritical CO₂ technique. They found that this encapsulation type can lead to the capsules with 1.44 and 7.21 pm with a FeSO₄-EE of ~25% and a vitamin D₃-EE of ~96%. A better storage stability for the encapsulating niosomes at 20° C was monitored than those stored at 4^°C for 21 days.