Application of lipid as emulsifier in the solvent evaporation technique in fabrication of polymeric nanospheres for controlled release of Taxol

This study was intended to examine the potential of application of 1,2-dipalmitoylphosphatidyl-choline (DPPC) as an emulsifier in the solvent evaporation technique, which is one of the most widely used methods to prepare polymeric microspheres and nanospheres for controlled release of an effective anticancer drug Paclitaxel (Taxol^(R)). The poly(D,L-lactic-co-glycolic acid) (PLGA, 75/25) nanospheres loaded with Taxol were prepared by the solvent evaporation technique with DPPC and/or poly(vinylalcohol) (PVA) as emulsifier(s). The fabricated nanospheres in various conditions were characterized by SEM and laser light scattering, which revealed that the size of nanospheres ranged from 400 to 900 nm. The encapsulation efficiency was measured by HPLC. The result showed that nanospheres fabricated with DPPC as emulsifier have higher encapsulation efficiency than those with PVA. It was also demonstrated that the EE of nanospheres fabricated with both DPPC and PVA as emulsifiers is higher than those of nanospheres with DPPC or PVA as emulsifier alone, which suggested that a synergetic effect may exist between PVA and DPPC. The surface property of nanospheres containing DPPC was also studied by XPS, which showed dominance of DPPC on the nanospheres surface. XPS study and the in vitro release experiment suggest that nanospheres fabricated with DPPC can be an improved drug delivery system