Preparation and drug release behavior of pH-responsive bovine serum albumin-loaded chitosan microspheres

Abstract

A novel inverse emulsion-ionic crosslinking approach was adopted to prepare pH-responsive chitosan microspheres and effect of preparation technique, such as chitosan concentration, emulsifier concentration, water/oil ratio and homogenization speed, on the morphology and property of the microspheres were investigated. The chitosan microspheres with spherical in shape, smooth surface, high productivity and promising pH responsiveness were obtained. On this basis, bovine serum albumin (BSA)-loaded chitosan microspheres was prepared to test the drug release behavior in buffers with different pH values. BSA-chitosan microspheres with particle sizes in range from 5 to 10μm released BSA slowly in neutral medium and released rapidly in acidic medium, and exhibited obviously pH-responsive release behavior. Korsmeyer–Peppas model can be used for describing BSA release kinetics from chitosan microspheres, which corresponded with a Fickian release behavior, and the diffusion through the swelling of chitosan microspheres was the main factor in controlling BSA release.