title: 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: OBJECTIVE
  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.
  
  
  METHODS
  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/bioadhesive 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.
authors: Department of Pharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Hat-Yai, Songkhla, Thailand.
authors: Krit
authors: K
authors: Suknuntha
authors: Vimon
authors: V
authors: Tantishaiyakul
authors: Nimit
authors: N
authors: Worakul
authors: Wirach
authors: W
authors: Taweepreda
mesh_terms: D000464:Alginates / Q000008:administration & dosage*; D000658:Amoxicillin / Q000008:administration & dosage* / Q000737:chemistry; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D002448:Cell Adhesion / Q000187:drug effects; D048271:Chitosan / Q000008:administration & dosage*; D020723:Glucuronic Acid / Q000008:administration & dosage; D019073:HT29 Cells; D006603:Hexuronic Acids / Q000008:administration & dosage; D006801:Humans; D011205:Povidone / Q000008:administration & dosage*; D012995:Solubility; D014783:Viscosity
chemical_list: D000464:Alginates; D000900:Anti-Bacterial Agents; D006603:Hexuronic Acids; D000658:Amoxicillin; D020723:Glucuronic Acid; D048271:Chitosan; D011205:Povidone