ABSTRACT
Aim: To prepare the influenza vaccine lyophilized liposomes and to characterize its particle distribution, encapsulation efficiency and immunogenicity. Methods: Flu vaccine liposome based on the method of thin-film evaporation was prepared using phospholipids , cholesterol and the purified influenza virus split vaccine, and was further subjected to frozen-drying. The polymorph was observed by microscope; the particle distribution and the average size were analysed by transmission electron microscope; its encapsulation efficiency was determined by Lowry method and the antibody titers were assessed by hemagglutination-inhibition after pulmonary delivery to mice. Results: The reconstitated influenza vaccine liposome under electronic microscope were round or elliptic particles evenly distributed at a mean size of 2. 14 祄, with the encapsulation efficiency of more than 80%. The antibody titer through pulmonary delivery was higher than that through intraperitoneal injection. Conclusion: The prepared influenza vaccine lyophilized liposomes possess high encapsulation efficiency, better particle distribution and marked immunogenicity through pulmonary delivery to mice. Pulmonary delivery of influenza vaccine liposomes is a potential immunization approach worthy of further exploitation.