Preparation and characterization of metronidazole loaded chitosan nanoparticles for drug delivery application

This study describes the preparation of mucoadhesive chitosan nanoparticles containing metronidazole (MZ) intended for colon-specific delivery. The chitosan nanoparticles were prepared by the ionic gelation method and their in vitro properties were studied. The release profiles of MZ from the nanoparticles were determined by UV-Vis absorption measurement at lambda(max) 278 nm. Scanning electron microscopy was used for morphology observation. The nanoparticles exhibited mucoadhesive properties, which diminished with increasing drug content. The nanoparticles with a particle size range between 200 and 300 nm exhibited excellent mucoadhesive properties. The results show that the formulated nanoparticles have succeeded in controlling the release of MZ over a 12-hr period. In conclusion, the release of MZ was found to be dependent upon the composition of the nanoparticles, the ratio of the components and possible particle size, as well as bioadhesive ability. Copyright (C) 2008 John Wiley & Sons, Ltd.