Preparation and Characterization of Cross-Linked Chitosan Microcapsules for Controlled Delivery of Oxytetracycline
Laboratory of molecular and macromolecular physical chemistry, University of Blida I, 09000 Blida, Algeria, 1Laboratory of Fibrous Polymers Treatment and Forming, University of Boumerdes, 35000 Boumerdes, Algeria, 2Institut de Recherche de Chimie Paris, CNRS-Chimie Paris Tech, 11 rue Pierre et Marie Curie, 75005 Paris, France
Laboratory of molecular and macromolecular physical chemistry, University of Blida I, 09000 Blida, Algeria E-mail: [email protected]
Formulations of encapsulated oxytetracycline in chitosan spherical beads have been developed in this work through the ionotropic gelation method in sodium tripolyphosphate or tripolyphosphate and characterized as drug delivery system to the gastrointestinal tract by Fourier transform infrared spectroscopy spectroscopy, thermal analysis and in vitro drug release in simulated gastric fluids. The Fourier transform infrared spectroscopy and differential scanning calorimetry measurements showed that tripolyphosphate and tripolyphosphate are cross linked ionically to chitosan and there was no significant drug interaction between the entrapped drug and the carrying polymer. With the respect to chitosan cross linking features, sodium hexametaphosphate seems to give better swelling, higher diffusion and faster release kinetics, while addition of glutaraldehyde as a second cross linking agent lowers the drug discharge. Release extent and kinetics were found to be pH dependent and approximated very well by the multistep models equations of Makoid-Banakar, Peppas-Sahlin and Korsmeyer-Peppas.