Optimization of α-tocopherol loaded solid lipid nanoparticles by central composite design

Solid lipid nanoparticle (SLN) systems were developed using response surface methodology to optimize the mean particle size, α-tocopherol recovery rate and zeta potential of SLNs containing α-tocopherol. The optimization of α-tocopherol-loaded SLNs was characterized by X-ray diffraction analysis, differential scanning calorimetry, and the analysis of morphology and physical stability. The optimal conditions for an α-tocopherol-loaded SLN preparation were a particle size, α-tocopherol recovery rate and zeta potential of 214.5 nm, 75.4% and −41.9 mV, respectively; this preparation was stable during storage at 6 °C for 21 days. Furthermore, Compritol® 888 CG ATO changed its crystalline nature from the β′ polymorphic form in the pure formulation to the α and β′ polymorphic forms in SLNs.