OBJECTIVE:To evaluate the application of mixture design in the design of formulation.METHODS:Isosorbide mononitrate (ISMN) was used as model drug,and the formulation of ISMN sustained-release tablet was optimized by the mixture design.The optimized ISMN sustained-release tablets were compared with the ISMN sustained-release tablets in market in respect of the release rate in vitro.RESULTS:The comparison between the validating value and the target value of the optimized sample showed a similarity factor(f2) of 86.56,and there were no differences between the optimized sample and that in market in respect of the drug release in vitro.CONCLUSION:The mixture design is applicable for the optimization of formulation and it can be used to predict the drug release in vitro.