With the dropping process of Xuesaitong Dropping Pills(XDP) as the study object, critical factors affecting the quality indicators of pill pass rate, average weight of drop pills and roundness were screened out, so as to deepen the understanding of the dropping process. The critical process units, critical quality attributes and potential critical process influencing factors of XDP were determined by risk analysis and prior knowledge, and then the critical influencing factors were screened out by Plackett-Burman design. First, according to the risk assessment, the critical technique of XDP preparation process was dropping, and then the critical quality attributes of dropping process were pill pass rate, average weight of drop pills and roundness. Then, according to fishbone diagram and failure mode and effects analysis(FMEA), potential critical influencing factors were determined as flow rate, matrix ratio, solid-liquid ratio, feed-liquid temperature, top temperature of condensate, bottom temperature of condensate and dropping distance. Finally, among these seven potential factors, the critical influencing factors were determined as material liquid ratio, dropping distance, top temperature of condensate, bottom temperature of condensate. This study revealed the potential of Plackett-Burman design in screening and understanding the influence of selected factors on XDP dropping process, which could provide a reference for studying the dropping process.
Keywords: Plackett-Burman design; Xuesaitong Dropping Pills; critical influencing factors; dropping process; risk analysis.