Preparation and characterization of PLGA nanoparticles

Nanoparticles were prepared by emulsion solvent evaporation method, using methylene chloride (DCM) as the organic solvent and poly vinyl alcohol (PVA) as the surfactant. Different formulation conditions such as surfactant concentration, drug amount, homogenization time, aqueous phase volume were investigated for drug entrapment efficiency, drug loading and particle size. It was found that PVA concentration less than 1% was unable to form a stable emulsion, increasing drug amount more than 30 mg didn't lead to any significant difference in drug entrapment efficiency or particle size, homogenization for 2 minutes led to particles having larger size  and higher entrapment efficiency than those obtained after 3 minutes homogenization, increasing the aqueous phase volume from 40 ml to 80 ml led to a significant increase in entrapment efficiency and a significant decrease in particle size.