Solubilization of vitamin e into H_II LLC mesophase in the presence and in the absence of vitamin C

The synergistic solubilization of two major hydrophilic (vitamin C, ascorbic acid, AA) and lipophilic (vitamin E, D-α-tocopherol, VE) antioxidants within reverse hexagonal (H_II) mesophases is reported. The H_II mesophases are composed, of monoolein (GMO)/VE/AA/water. A wide range of VE concentration was examined (on the expense of GMO concentrations) while the AA and water concentrations remained constant (4 and 12.5 wt %, respectively) in order to expand the H_II mesophase. SAXS and DSC combined with ATR-FTIR techniques were utilized to study the interactions between each solubilizate and the Hn component that enabled the synergistic accommodation of the hydrophilic and hydrophobic molecules. It was revealed that up to 27 wt % VE solubilized within the H_II mesophase. This hydrophobic additive localized at the lipophilic GMO tail region solvating the surfactant tails, thereby enabling the formation of the H_II; structure. As a result, the lattice parameter and the melting point of the hydrophobic tails decreased. Above 27 wt % VE (up to 33 wt %), once the GMO lipophilic region was homogenously solvated, additional VE molecules located closer to the interface. At this range of concentrations, new hydrogen bonds between O-H groups of VE and O-H groups of GMO were formed. Once 35 wt % VE was introduced, the H_II structure transformed to facecentered reverse micellar cubic phase (Fd3m, Q²²⁷).