Preparation factors affecting the properties of polylactide nanoparticles: a factorial design study.

PLGA nanoparticles were produced using a w/o/w emulsification solvent evaporation method incorporating pilocarpine HCl as a model drug. The influence of four preparation parameters on the particle properties was studied. The factors studied were the concentration of the stabilizer in the outer water phase, the presence of buffer in the outer water phase, the amount of drug relative to the amount of polymer and the type of PLGA used. Particle size was influenced by the concentration of PVA in and the addition of buffer to the outer water phase. The ratio drug/polymer had an effect on the drug entrapment.