Abstract: Influenzal vaccine chitosan microparticles were prepared with tripolyphosphate(TPP) by ionic gelation method.The working mass fraction of chitosan was 1%. Morphologies of chitosan microparticles were affected by concentration of TPP, lower concentration of TPP(200 μg/mL) made the microparticle solution give sediment overnight, Whereas, higher concentration of TPP(800 μg/mL) made microparticles gather together . The release of vaccine from chitosan microparticles decreased when cross-linking ratio increased. The pH of chitosan solution had no effect on morphologies and release behavior. The results indicate that pH=5.6, cross-linking ratio 1∶3, mass concentration of TPP 400 μg/mL are the optimum conditions to prepare influenzal vaccine chitosan microparticles via morphologies and release behavior.

Key words: Ionic gelation, Chitosan microparticles, Influenza vaccine, Sodium tripolyphosphate