Characterization of muco- and bioadhesive properties of chitosan, PVP, and chitosan/PVP blends and release of amoxicillin from alginate beads coated with chitosan/PVP

Abstract

Purpose: To investigate the muco/bioadhesive properties of chitosan, polyvinylpyrrolidone (PVP), and chitosan/PVP blends and the release of amoxicillin (AMX) contained in AMX-alginate beads coated with these materials. Method: Chitosan, PVP, and chitosan/PVP blends at various volume ratios were coated onto calcium alginate beads containing AMX. The muco/bioadhesive properties of all materials and the AMX-alginate beads coated with these materials were characterized. Results: Measurements of their viscosity, texture, and adhesion to HT29 cells demonstrated that chitosan/PVP at a volume ratio of 5/5 had the best muco/bioadhesive properties when compared with chitosan, PVP, and blends of other ratios. Wash-off tests indicated that the mucoadhesive property of the coated AMX-alginate beads was significantly higher than that of the uncoated beads. Diffuse reflectance infrared Fourier transform spectroscopy showed that there were interactions between chitosan–PVP, chitosan–mucin, PVP–mucin, and chitosan/PVP blend–mucin. Scanning electron microscopy revealed that the surfaces of the coated beads were smoother than those of the uncoated beads. All coated AMX-alginate beads were able to provide a controlled release of AMX with Super Case II transport properties, at a pH of 4. This was probably a result of the rapid and extensive swelling of the alginate beads. The more rapid release of AMX at pH 1 was probably because of the rapid dissolution of the drug at this pH. Conclusions: From the controlled drug release and muco/bioahesive properties of these coated AMX-alginate beads, we suggest that the alginate-coated beads might be a promising drug delivery system to assist with the eradication of Helicobacter pylori infections.