Stability of influenza vaccine liposome powder

The physical stability of prepared influenza vaccine liposome powder was observed,the portion of vitamin E ( VitE) was optimized using encapsulation efficiency and oxidation-index as indexes,and the immunogenicity and biological stability of the product containing the optimized amount of VitE was studied. The liposome powder was put at the temperature of ( 37 ± 2) ,( 25 ± 2) ,and 4 ℃ and sampled at due time. The encapsulation efficiency was determined in order to study its physical stability. The liposome powder had satisfying physical stability under ( 37 ± 2) ℃ for 14 d,( 25 ± 2) ℃ for 90 d and 4 ℃ for 180 d. The influenza vaccine liposome powder was stored with varied amount of VitE under ( 37 ± 2) ℃ ,the samples were taken at different times,the encapsulation efficiency and oxidation indexes were measured, so that the optimum amount of VitE could be determined. The influenza vaccine liposome powder was stored with optimized VitE under ( 37 ± 2) ℃ for 1,14 and 21 d,the antibody titers were determined by hemagglutination-inhibition ( HI) method after pulmonary delivery to mice at the dose of heamagglutinin ( 6 μg /mouse) . The product with 5% VitE had the highest encapsulation efficiency,optimum outlook,and satisfied biostability under ( 37 ± 2) ℃ for 21 d.