关键词: 维生素B₁₂注射液, 动态浊度法, 细菌内毒素, 最大有效稀释倍数, 干扰试验

Abstract:

Objective： To improve product quality control and ensure clinical medication safety， this study established a kinetic turbidimetric assay for detecting bacterial endotoxin level in vitamin B₁₂ injection.Methods： According to the requirements of the "1143 Bacterial Endotoxin Test Method" in the 2020 edition of the Pharmacopoeia of the People's Republic of China， the Pyros Kinetix^® Flex 96 （PKF 96） bacterial endotoxin quantitative detection system was utilized and non-pyrogenic water was used to dilute and dissolve Limulus Amebocyte Lysate （LAL）， establishing a standard curve for bacterial endotoxins and determining the dilution factor. Interference tests were performed by measuring the recovery rate of spiked endotoxins in the test solution， allowing for the quantitative determination of bacterial endotoxin content in the samples.Results： The linear range of the endotoxin detection standard curve was 0.005 to 5.0 EU·mL⁻¹ （r = -0.993）， with the regression equation logT = -0.288logC + 2.81. The test samples showed no interference when diluted by 4， 8， and 16 times， and the bacterial endotoxin recovery rates were within the 50% to 200% range. The endotoxin quantification results from 57 batches of samples were found to be compliant with the requirements.Conclusion： The kinetic turbidimetric assay established on the platform of the bacterial endotoxin quantitative detection system is applicable for the quantitative detection of bacterial endotoxins in vitamin B₁₂ injections. The establishment of this method not only meets regulatory requirements but also provides significant technical support for strengthening the quality control of injections and ensuring their safe clinical use.

Key words: Vitamin B₁₂ , injection； , Kinetic turbidimetric assay； , Bacterial endotoxins； , Maximum valid dilution； , Interference test