Quality control of osmolality of viral vaccines

Abstract

Objective To compare the difference of mean osmolalities among 6 viral vaccines and observe lot-to-lot stability of a single vaccine,and provide a basis for increasing an approach of quality control of viral vaccines.Methods The osmolalities of 5 live attenuated viral vaccines (measles,mumps and rubella combined vaccine,measles and mumps combined vaccine,measles vaccine,rubella vaccine,varicella vaccine) and influenza vaccine (split virion) were determined by a method of freezing point depression.Coefficient of variation was calculated.The mean osmolality of measles,mumps and rubella combined vaccine was used as a control and mean osmolalities of the remaining 5 vaccines were compared with the control by homogeneity test of variance and hypothesis test.Results There was no significant difference of mean osmolalities between measles and mumps combined vaccine and the control (t =1.66,P ＞ 0.05).The mean osmolalities of measles vaccine,rubella vaccine,varicella vaccine,and influenza vaccine were significantly different from that of the control (Z ＞ 1.96,P ＜0.001).The lot-to-lot stability of a single vaccine was good.None of the coefficients of variation were more than 3％,and the measurements ranged between 90％ and 110％ of the mean values.Conclusions There are some differences of the osmolalities among 6 viral vaccines,but lot-to-lot stability of a single vaccine is satisfactory.Therefore,corresponding criteria should be set for different vaccines. Key words: Viral vaccines; Freezing point depression; Osmolality; Quality control