Objective: To optimize the formulation and preparation technology of Xiaoyao tablets based on quality by design (QbD). Method:Xiaoyao tablets were prepared by wet granulation and granule compression.Firstly

the risk factors that may affect the quality of the tablets were evaluated.Plackett-Burman experimental design was used to screen the prescription factors and process parameters that had significant influence on the index.Taking formability of granules

angle of repose and appearance of tablets

disintegration time as evaluation indexes

the formulation of Xiaoyao tablets was optimized by mixture design. Result:By taking risk assessment and Plackett-Burman test

it was confirmed that the ratio of extract powder to excipients

the ratio of starch to lactose

the amount of disintegrant and lubricant were the key factors affecting the experimental results.The regression model established by the mixture design had significant significance and the model had good predictability.Based on the model

the optimal formulation was chosen within the optimal prescription area as dry extract powder-starch-lactose-croscarmellose sodium-magnesium stearate (73.2:13.8:10:2:1).According to this prescription

Xiaoyao tablets was prepared

its average particle forming rate reached 87.44%

the angle of repose was 34.97°

the score of tablets' appearance was 5 points and the disintegration time was 32.3 minutes

the comprehensive score reached 75.63 points. Conclusion:It is feasible to optimize the prescription and process parameters of Xiaoyao tablets based on QbD concept and mixture design method.The prescription optimized by mixture design is reasonable

the process is stable and feasible

which can provide a reference for industrial production of Xiaoyao tablets.