Study on Bacterial Endotoxin Test of Cholesterol

OBJECTIVE To establish a bacterial endotoxin detection and control method for insoluble excipient cholesterol(for injection).METHODS The bacterial endotoxin quality control method for cholesterol was established by screening the organic solvent suitable for cholesterol dissolution and screening through 9 methods to eliminate the interference of organic solvent and cholesterol to the endotoxin test. The detection conditions were as follows: cholesterol was prepared with anhydrous ethanol into 20 mg·mL^-1 solution, diluted 100 times with 0.5 mg·mL^-1 polyoxyethylene(35) castor oil solution instead of bacterial endotoxin test water, and detected by kinetic-turbidimetric assay of endotoxin test.RESULTS The recoveries of the kinetic-turbidimetric assay limulus reagent from two manufacturers were 50%-200%, and the values of endotoxin were all <0.1 EU·mg^-1. At present, this variety could only be tested with the most sensitive reagent from one manufacturer when use gel method. Therefore, cholesterol detection by gel method was not recommended.CONCLUSION A kinetic-turbidimetric assay for the determination of bacterial endotoxin in cholesterol(for injection) is established for quality control.