Development and characterization of phytosterol nanoemulsions and self-microemulsifying drug delivery systems

The aim of this study is to develop a self microemulsion drug delivery system for phytosterols to improve the solubility and bioavailability. The results showed that the formulation of phytosterol self- microemulsion is: lemon essential oil in oil phase, polyoxyethylene hydrogenated castor oil 40 and Tween 60 in emulsifier, polyethylene glycol 400 in co-emulsifier, Km = 7:3, Kp = 3:1, Ke = 50%. The drug loading of phytosterol self-microemulsion prepared by this method was 87.22 mg/g, encapsulation efficiency was 89.65%, particle size was 48.85nm, potential was -12.863mV. In vitro release experiment showed that the release of phytosterols in microemulsion was more than 90%, and the release curve was in accordance with the first-order kinetics equation.