Preparation Of Drug-loaded Nanoparticles And Research Of Drug Delivery Path

This paper aimed to prepare insulin-loaded nanoparticles(NPs) and investigatethe physico-chemical characteristics of NPs, and also tried to study the drug efficacyin vivo. As the same time, the transdermal drug delivery properties of polyesternanoparticles were inspected. Biodegradable and biocompatible polylacticacid/poly(ethylene glycol)(PEDLLA) amphiphilic diblock copolymers were chose asthe carring material to prepare NPs. Insulin-loaded PEDLLA nanoparticles wereprepared by a multiple emulsion/solvent evaporation method. The encapsulationefficiency was determined by HPLC after separating the NPs from the suspensionunder ultra centrifugation. Orthogonal experiments were performed to optimum thetechnique conditions to prepare NPs. The particle size, distributions and surfacemorphology of the NPs were examined by laser particle analyzer and transmissionelectron microscopy, respectively. The results show that the character andconcentration of the emulsifers have important influence on the characteristics of theNPs in the multiple emulsion/solvent evaporation experiment. the NPs prepared byusing the optimum technique take regular morphology and well-distribution with amean diameter of (152.3±15.2)nm, a polydispersity index of 0.179±0.041 and anencapsulation efficiency up to 40%. Neither layer and flocculation pheonomena, northe change in diameter, shape and encapsulation efficiency were found for NPsdispersions in water after stored for 6 months at 4℃。In this thesis, paclitaxel or buprofen loaded polymer nanoparticles were alsoprepared by the solid dispersion technique with polylactic acid/poly(ethylene glycol)amphiphilic diblock copolymer as the carring material. The obtained drug loadedparticles were nanometer size with narrow particle size distribution. The studyingresults of the transmission electron microscopy show that the drug-loaded polymernanoparticles take a round shape with inner core and outer shell. The transdermalrelease efficiency of the PMT was studied by using Franz Diffusion Cell and miceskin at 35℃,and measured by using IR spectra and HPLC methods . The studyingresults indicate that the polymer micelles can carry the loading drug through the miceskin as a whole nanoparticles and release the drug ,which means that PMT is possibleto be applied in the transdermal drug release systems.