Nanoprecipitation–Miniemulsion polymerization combined method: A novel approach to synthesis drug loaded nanoparticles with tunable characteristics

Abstract

In this research polystyrene nanoparticles (NPs) were synthesized using a novel straightforward approach based on the nanoprecipitation and miniemulsion polymerization. Nanoprecipitation or solvent shifting method was applied to prepare primary emulsions. For this purpose, oil phase consisting of solution of styrene, alcohol and polylactide oligomer as a cosurfactant, was added to aqueous phase consisting of water and surfactant. Primary emulsions were easily formed as a result of water-alcohol interdiffusion. Afterwards polystyrene NPs were synthesized by free radical miniemulsion polymerization process. Effect of variety of parameters, such as initiator nature (water-soluble or oil-soluble), cosurfactant, styrene to alcohol and alcohol to water ratio, on polymerization yield and NPs characteristics were investigated. Sodium 11-acryloyl-aminoundecanoate was tested as an amphiphilic polymerizable surfactant to synthesize polystyrene NPs with surface functional groups. Moreover, to examine the applicability of proposed approach for drug immobilization, rifampicin as a hydrophobic anti tubercular model drug was investigated. NPs characteristics were analyzed using scanning electron microscopy, light scattering and zeta potential measurements. Consequently, it was shown that nanoprecipitation–miniemulsion polymerization approach can be considered as a straightforward, low energy emulsification method to synthesize polymeric NPs with tunable characteristics.