Bergan T, Arnold E, Withander L
Methods Find Exp Clin Pharmacol. 1980 Apr;2(3):145-50.
Chemical (thin layer chromatography/fluorescence quenching in situ) and microbiological (agar well, diffusion technique with Clostridium perfringens as indicator strain) methods of assaying metronidazole have been compared. On dummy samples made with pure metronidazole in pooled human serum, both methods had a coefficient of variation ranging from 5.5 to 9.6 per cent of the mean. The microbiological method slightly underestimated the real amounts, and also had lower values than the chemical procedure. Comparison of serum and urine samples taken during the early, middle and late periods after medication to volunteers showed that biotransformation to antibacterially active metabolites contributes significantly to the antibacterial activity, particularly in urine. Biotransformation explains why microbiologically determined concentrations were higher than those determined chemically in samples taken at least 16-20 hours after intake of tablets or suppositories. It is important to be aware of the circumstance that the results of microbiological assay are sensu strictu limited to the particular indicator strain used, since other bacteria may exhibit other patterns of sensitivity to metronidazole and its metabolites.
已对测定甲硝唑的化学方法（薄层色谱法/原位荧光猝灭法）和微生物学方法（琼脂孔法，以产气荚膜梭菌为指示菌株的扩散技术）进行了比较。在用纯甲硝唑在混合人血清中制备的虚拟样品上，两种方法的变异系数均为平均值的5.5%至9.6%。微生物学方法略微低估了实际含量，且其值也低于化学方法。对志愿者用药后早期、中期和晚期采集的血清和尿液样本进行比较表明，生物转化为具有抗菌活性的代谢物对抗菌活性有显著贡献，尤其是在尿液中。生物转化解释了为什么在摄入片剂或栓剂至少16 - 20小时后采集的样本中，微生物学测定的浓度高于化学测定的浓度。必须注意的是，严格来说，微生物学测定的结果仅限于所使用的特定指示菌株，因为其他细菌可能对甲硝唑及其代谢物表现出不同的敏感性模式。
