[Objective] The aim of this study is to evaluate the safety and bacteriostasis of Yandureqing(AEE)and its microemulsion(AEE-ME).[Method]The acute toxicity was tested in mice by intragastric administration,and median lethal dose(LD50)as well as its 95% confidence interval was calculated by modified Karber method;the bacteriostasis was investigated by cylinder plate method.[Result]LD50 of AEE in mice was 10.937 g/kg with the 95% confidence interval of 9.309-12.850 g/kg;and LD50 of AEE-ME in mice was 5.357 g/kg with the 95% confidence interval of 4.388-6.566 g/kg.The MICs of AEE to Escherichia coli O149 from swine,Staphylococcus aureus,Salmonella pullorum and Streptococcus agalactiae were 10.00,20.00,20.00 and 10.00 mg/ml,respectively;while the MICs of AEE-ME to the 4 kinds of bacteria mentioned above were 5.00,10.00,5.00 and 5.00 mg/ml in turn,and that to Pseudomonas aeruginosa is 20.00 mg/ml.[Conclusion]AEE is an actually nontoxic drug and AEE-ME belongs to the low toxic preparation.AEE and AEE-ME have obvious bacteriostasis,in which AEE-ME is superior to AEE.
