Study on feasibility of Gel-clot method for bacterial endotoxin test of denosumab injection
Objective:To explore the feasibility of gel-clot method for bacterial endotoxin test of denosumab injec-tion.Methods:Referring to general chapter 1143 in ChP 2020.Vol Ⅲ and Technical Report No.82 on Low Endotoxin Recovery published by PDA,bacterial endotoxin was detected by turbidimetric kinetic method and the endotoxin recovery of denosumab injection with different dilutions was calculated.Then based on the recovery,it was judged whether there was a LER issue and it was predicted how well the samples interfered the reaction between TAL reagent and bacterial endotoxin.Pre-experiment of gel-clot interference test was performed with TAL reagents of different sensitivity.The gel-clot interference test was performed for three batches of samples and the bacterial endotoxin was tested with TAL reagents from different manufacturers separately.Results:Denosumab injection had no LER issue,and whose high concentration had the interference on the reaction between TAL reagent and bacterial endotoxin.The interference of gel-clot TAL reagent having a sensitivity of not less than 0.25 EU·mL-1,was elim-inated by diluting the samples to 6 mg·mL-1 with BET water.Conclusion:The gel-clot method for the detection of bacterial endotoxin in denosumab injection is feasible and can be used as a routine quality control method.