ObjectiveMethoxy poly (ethylene glycol)-poly (lactic acid) (mPEG-PDLLA) was used to increase water solubility of netupitant, thus to provide the experimental basis for development of the injection of netupitant.MethodsFilm hydration method was ultilized to prepare the netupitant-loaded mPEG-PDLLA nanoparticles (NT/mPEG-PDLLA-NPs). The preparation formulation and technology were optimized based on the single factor tests by investigating the effect of netupitant/mPEG-PDLLA mass ratio (m/m), filming temperature and time on the mean particle diameters and loading capacities. The size distributions and Zeta potentials of NT/mPEG-PDLLA-NPs were investigated using dynamic light scattering analysis, and the morphology was observed under the transmission electron microscope (TEM). The cytotoxicity of NT/mPEG-PDLLA-NPs evaluated by MTT method.ResultsThe optimal NT/mPEG-PDLLA-NPs were achieved at the netupitant/mPEG-PDLLA mass ratio of 1/6 with filming temperature at 55 ℃ and filming time for 30 min. The resulting NT/mPEG-PDLLA-NPs displayed an opalescent and translucent appearance, with a high loading capacity of 14% and netupitant concentration of 10 mg/mL. NT/mPEG-PDLLA-NPs showed a spherical morphology, with a mean diameter of 58 nm and a nearly neutral Zeta potential of -0.29 mV. The NT/mPEG-PDLLA-NPs showed a cytotoxicity similar to free NT.ConclusionNetupitant was successfully loaded into mPEG-PDLLA-NPs to significantly increased the water solubility, thus providing the experimental foundation for the further development of injection of netupitant.