화학공학소재연구정보센터
Journal of Applied Polymer Science, Vol.85, No.13, 2625-2634, 2002
Preparation of core-shell type nanoparticles of diblock copolymers of poly(L-lactide)/poly(ethylene glycol) and their characterization in vitro
Core-shell type nanoparticles of poly(L-lactide)/poly(ethylene glycol) (LE) diblock copolymer were prepared by a dialysis technique. Their size was confirmed as 40-70 nm using photon correlation spectroscopy. The H-1-NMR analysis confirmed the formation of core-shell type nanoparticles and drug loading. The particle size, drug loading, and drug release rate of the LE nanoparticles were slightly changed by the initial solvents that were used. The drug release behavior of LE core-shell type nanoparticles showed an initial burst during the first 12 h and then a sustained release until 100 h. The degradation behavior of LE block copolymer nanoparticies was divided into three phases: the initial rapid degradation phase, the stationary phase, and the rapid degradation phase until complete degradation. It was suggested that lidocaine release kinetics were predominantly governed by the diffusion mechanism in the initial burst phase and after that by both of the diffusion and degradation mechanisms.