Investigation of the stability of PEG stearate-coated Chitosan nanoparticles loaded with levothyroxine
Subject Areas : Journal of Nanoanalysis
1 - Department of Chemistry, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
Keywords: Stability, polymer, Nanoparticle, Chitosan, PEG Stearate, levothyroxine,
Abstract :
We report the formation and characterization of PEG stearate (PEG)-coatedChitosan (CS) nanoparticles. Chitosan nanoparticles were synthesized usingtripolyphosphate (TPP) via the ionic crosslinking method. Preparation of PEGStearate-grafted Chitosan is essential to improve the biocompatibility and watersolubility of Chitosan. The size and morphologies of Chitosan nanoparticleswere measured with transmission electron microscopy and scanning electronmicroscopy. Sizes of Chitosan nanoparticles were in the range of 150-200nm. The particle size and zeta potential of PEG Stearate-coated Chitosanhad been measured at 187.5 nm by Photon Correlation Spectroscopy (PCS).Drug entrapment efficiency (EE) was obtained to be 99%. The purpose of thepresent work was to develop a new nanoparticle system, consisting of polymericnanoparticles coated with PEG Stearate. The modification procedure led to areduction in the zeta potential values, varying from +43.3 mV for the uncoatedparticles to +20 mV for that of PEG Stearate-coated Chitosan. PEG Stearatecoated nanoparticles were more stable due to their polymer coating layer whichprevented aggregation of Chitosan nanoparticles. Consequently, it is possible thatthe PEG Stearate surrounds the particles reducing the attachment of enzymesand further degradation of the polymeric cores. Properties nanoparticles wereaffected by the preparation variables and the coating layer. Chitosan nanoparticlesshowed a smooth surface and globular shape. In this study, we explored therelease behavior of levothyroxine was affected by the coating layer. Coatingsurface leads to a decrease in the burst release effect compared to uncoatednanoparticle due to gradual release of adsorbed levothyroxine from PEG coatedChitosan nanoparticles.