Effect of chitosan on physicochemical properties of exenatide-loaded PLGA nanoparticles

Abstract

The aim of this study was to test stability of exenatide and compare physicochemical properties of PLGA nanoparticles. To make small, stable, uniform and highly encapsulated nanoparticles, various factors such as the components (polymer and stabilizer) and preparation condition (organic phase, temperature or sonication time) were considered. We tested the effect of organic phase, acid/base, ultrasonication time or temperature on exenatide to decide preparation condition of PLGA nanoparticles. And, PLGA nanoparticles were prepared by the double emulsion-solvent evaporation method and chitosan was selected as stabilizer. PLGA nanoparticles were characterized by yield, encapsulation efficiency, drug loading, particle size, zeta potential, polydispersity index and morphology. In this study, PLGA nanoparticles showed different physicochemical properties according to chitosan molecular weight. In case of particle size, PLGA nanoparticles using 0.5 g chitosan (4 kDa) showed biggest particle size (781.4 ± 24.1 nm) among PLGA nanoparticles prepared in this study and PLGA nanoparticles using 1 g chitosan (2 kDa) showed highest encapsulation efficiency (52.8 ± 1.7 %) among PLGA nanoparticles prepared in this study. And, all of PLGA nanoparticles using chitosan showed that polydispersity index was low and zeta-potential was increased. These results suggest that chitosan molecular weight affects physicochemical properties of PLGA nanoparticle.