Preparation of PLGA nanoparticles using TPGS in the spontaneous emulsification solvent diffusion method

D-alpha-tocopheryl poly (ethylene glycol) 1000 succinate (TPGS) is a widely used form of vitamin E that has been used as a solubilizer, an emulsifier and as a vehicle for drug delivery formulations. In this study, poly lactide-co-glycolide (PLGA) nanoparticles were prepared by spontaneous emulsification solvent diffusion (SESD) method. TPGS as an emulsifier and further as a matrix material blended with PLGA was used to enhance the encapsulation efficiency and improve the drug release profile of nanoparticles. Rifampicin and estradiol valerate were used as model drugs with different water solubility. The effect of formulation parameters such as drug/polymer ratio, oil phase combination, volume and surfactant content was evaluated. The surface morphology and size of the nanoparticles were studied by scanning electron microscopy (SEM) and laser light scattering. Drug encapsulation efficiency and in vitro drug release profiles of nanoparticles were determined using high performance liquid chromatography (HPLC). The nanoparticles prepared in this study were spherical with size range of 150-250 nm. It was shown that TPGS was a good emulsifier for producing nanoparticles of hydrophobic drugs and improving the encapsulation efficiency and drug loading and drug release profile of nanoparticles. However, the drug loading efficiency of rifampicin, a slightly water-soluble molecule, was significantly lower than that of estradiol valerate, a water insoluble molecule.