Objective: To investigate effects of temperature and pH on agglomeration state of endotoxin in glycyrrhizic acid solution. Method: Under different temperature and pH conditions

glycyrrhizic acid solution was filtered with 30 kDa Millipore membrane

the concentration of Endotoxin in ultrafiltrate was determined by dynamic turbidity method

contents change of active components was examined by HPLC

particle size of agglomeration state of endotoxin was determined with nanometer particle size instrument under different temperature and pH conditions. Result: When temperature was 60 ℃ and pH was 4

particle size distribution and removal of endotoxin agglomeration state were optimal.The contents of active components in glycyrrhizic acid solution was above 98% after filtering by 30 kDa Millipore membrane. Conclusion: With increasing of temperature

particle size distribution and removal of endotoxin agglomeration state increased

but when pH increased from 4 to 10

particle size and removal decreased.