Formulation and characterization of α-tocopherol loaded poly ɛ-caprolactone (PCL) nanoparticles

α-tocopherol-loaded poly ɛ-caprolactone (PCL) nanoparticles were prepared by emulsion solvent evaporation with ultrasonification technique. The influences of PCL concentration (3 and 5 g/100 mL), solvent in the oil phase (methylene chloride (DCM) and methylene chloride: acetonitrile = 50:50 (DCM:ACN)), and ultrasonification time (1, 2, and 3 min) were investigated. Encapsulation efficiency (%) was calculated by Duncan’s multiple rage tests and it decreased from 87.73 to 57.45 when ultrasonification time was increased from 1 to 3 min. DCM as a solvent in the oil phase and 5 g/100 mL PCL showed better encapsulation efficiency than DCM:ACN and 3 g/100 mL PCL. Particle mean size was decreased when ultrasonification time was increased from 1 to 3 min. Nanoparticles with DCM as a solvent in the oil phase had larger particle mean size than the particle with DCM:ACN. There were no significant differences in particle mean size between two PCL concentrations. PCL with 3 g/100 mL concentration had higher α-tocopherol loading (%) than 5 g/100 mL PCL. Overall, 5 g/100 mL PCL in DCM as solvent in the oil phase with 3 min ultrasonification time showed the best encapsulation formulation.