Department of Botany and Microbiology, College of Science, King Saud University, P. O. Box 2455, 11451, Riyadh, Saudi Arabia.
World J Microbiol Biotechnol. 2024 Feb 13;40(3):96. doi: 10.1007/s11274-024-03890-7.
The preservation of drug stability in biological evidence during the processes of collection and storage poses a substantial obstacle to the progress of forensic investigations. In conjunction with other constituents, the microorganisms present in the samples play a vital role in this investigation. The present investigation employed the high-performance liquid chromatography (HPLC) technique to assess the stability of (1R,2 S)-(-)-2-methylamino-1-phenyl-1-propanol hydrochloride in plasma and urine samples that were inoculated with Escherichia coli. These samples were subjected to storage conditions of 37 °C for 48 h and - 20 °C for a duration of 6 months. Minimal inhibitory concentration (MIC) and Minimal bactericidal concentration (MBC) of MPPH against E. coli were determined using microdilution method. The stability of MPPH in plasma and urine samples inoculated with E. coli was investigated using HPLC method. The results showed the MIC and MBC of MPPH were 87.5 ± 25 ppm and 175 ± 50 ppm, respectively. While MPPH remained stable in plasma for 48 h at 37 °C, it showed a notable decrease of about 11% in stability when stored in urine for the same period and temperature. From the beginning of the first month, a decrease in the stability of the compound appeared in all samples that were stored at - 20 °C, and the decrease reached 7% for plasma samples and about 11% for urine samples. The decrease in the stability reached its peak in the sixth month, reaching more than 30% and 70% of plasma and urine samples preserved at - 20 °C. This work concluded that E. coli can negatively affect the stability of MPPH in plasma and urine samples. This may lead to incorrect conclusions regarding the analysis of biological samples in criminal cases.
在采集和储存过程中，药物稳定性在生物证据中的保存对法医学调查的进展构成了重大障碍。在这项调查中，与其他成分一起，样品中存在的微生物在调查中起着至关重要的作用。本研究采用高效液相色谱（HPLC）技术评估了在接种大肠埃希菌的血浆和尿液样品中（1R，2S）-（-）-2-甲基氨基-1-苯基-1-丙醇盐酸盐的稳定性。这些样品在 37°C 下储存 48 小时，并在-20°C 下储存 6 个月。使用微量稀释法测定 MPPH 对大肠埃希菌的最小抑菌浓度（MIC）和最小杀菌浓度（MBC）。使用 HPLC 法研究了在接种大肠埃希菌的血浆和尿液样品中 MPPH 的稳定性。结果表明，MPPH 的 MIC 和 MBC 分别为 87.5±25ppm 和 175±50ppm。虽然 MPPH 在 37°C 下的血浆中 48 小时保持稳定，但在相同温度和时间下储存在尿液中时，其稳定性明显下降约 11%。从第一个月开始，所有在-20°C 下储存的样品中的化合物稳定性都开始下降，在血浆样品中下降了约 7%，在尿液样品中下降了约 11%。在第六个月，稳定性下降达到峰值，在-20°C 下保存的血浆和尿液样品分别下降了超过 30%和 70%。这项工作得出结论，大肠埃希菌会对 MPPH 在血浆和尿液样品中的稳定性产生负面影响。这可能导致在刑事案件中对生物样本分析的不正确结论。
