Anal, Anil Kumar creator Stevens, Willem Frans Chairperson Korbtham Sathirakul Examination committee Suwalee Chandrkrachang Examination committee Rakshit, Sudip Kumar Examination Committee Montet, Didier Examination committee Pakorn Nuchnoi Examiantion Committee Government of Austria Scholarship donor text series technical report th Bangkok Asian Institute of Technology 1998 continuing eng 78 leaves In this study, both chitosan beads and chitosan membrane have been investigated for applications in systems of controlled release of phaimaceuticals. Chitosan beads can be prepai-ed by microencapsulation of chitosan droplets. Microencapsulation comprises various technologies that can be used to coat small particles of solid or droplets of liquid dispersion with a thin coating layer. The dropping of dissolved chitosan into a solution of tripolyphosphate (TPP) leads instantaneously to the formation of beads by ionotropic gelation without using any sophisticated instruments. Conditions of microencapsulation have been investigated to optimize bead formation and entrapment of the model protein, bovine serum albumin (BSA). The speed of droppings, a slight stirring speed of TPP solution, 5-7 cm dropping distance from the surface of TPP solution and the type, concentration, and viscosity of chitosan solution were fotmd the major influensive parameters to form smooth and spherical chitosan beads. Crosslinking between chitosan and TPP occurs within 15 minutes. The pH 7.2 ofTPP was found the optimum pH for the maximum entrapment of bovine serum albumin (BSA), which was used as model drug for this study. The degree of deacetylation of chitosan showed an influensive on the entrapment of BSA while the concentration ofTPP, viscosity of chitosan solution ai1d more than 3% load of BSA did not have any effect. The chitosan beads/microcapsules were found to swell in acidic medium (0.1 N HCl). The release of BSA from the chitosan microcapsules was found depending upon the pH of the dissolution medium, drying condition, and the type of chitosan. Chitosan membrane prepared from chitosan with a 95% degree of deacetylation showed similar behavior as of commercially available cellulose membrane. The equilibrium dialysis for all model drugs aspirin, phenobarbitone Na salt, and Sulfanilamide occurred within two hours in both cellulose and chitosan membranes. The fraction of unbound drugs could be determined by using chitosan membrane. The unbound fractions of drugs obtained by using commercial regenerated cellulose membrane were comparable with those obtained by using chitosan membrane. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development Thesis (M.Sc.) - Asian Institute of Technology, 1998 Chitosan Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B13238 http://203.159.5.9/ait-thesis/detail.php?q=B13238 200499 20260817172702.0