Comparative mucopenetration ability of metronidazole loaded chitosan and pegylated chitosan nanoparticles

Abstract

Objective: The objective of this study is to compare the mucopenetration ability of metronidazole loaded chitosan (CS) and pegylated CS nanoparticles. Methods: Nanoparticles were prepared by ionic gelation technique using negatively charged pH sensitive polymer, hydroxyl propyl methyl cellulose phthalate with positively charged CS and methoxy polyethylene glycol-grafted-CS (mPEG-g-CS). mPEG-g-CS was synthesized by formaldehyde linkage method and characterized by Fourier transform infrared spectroscopy. The optimized formulations were compared for morphology, particle size, polydispersity index (PDI), entrapment efficiency, bioadhesion detachment force, in vitro and in vivo mucopenetration for CS-mPEG-g-CS nanoparticles. Results: The morphological assessment revealed smooth spherical particles with uniform dispersions. The optimized formulations particle size was found to be 202.7±27 nm and 294.1±46 nm, zeta potential 26.94±2.4 mV and 6.0±1.3 mV. PDI 0.231 and 0.268, entrapment efficiency 79.8±5.4% and 83.6±9.7%, bio-adhesion detachment force 14.98*103 dyne/cm2 and 10.67*103 dynes/cm2, in vitro mucopenetration 78% and 98% for CS-mPEG-g-CS, respectively. The qualitative in vivo mucopenetration result confirms retention of fluorescein isothiocyanate (FITC) labeled mPEG-g-CS nanoparticles till 24 hrs. Conclusion: Nanoparticles with lesser zeta potential and mucoadhesion showed higher mucosal penetration which is evident from FITC labeled histopathological mucus penetration test. Studies thus provided evidence that planned pharmaceutical strategies open new vistas for effective treatment of mucosal infections.