Abstract:
The ICH guidelines recommend reporting thresholds for regular impurities in drug substances at the level of 0.05% or 0.03% (w/w) depending on the maximum daily intake. Therefore, any instrumental method of analysis applicable to the impurity analysis should be able to detect and quantify the analytes at those levels. This investigation was designed to verify the suitability of 1H NMR spectroscopy for the detection of impurities, as a first step in the process before attempting quantification. In order to minimize demand on equipment, this study employed a 400 MHz instrument for structural confirmation and signal assignments of choline (1) and O-(2-hydroxyethyl)choline (2), a known impurity. The limit of detection (LOD) of 2 in 10 mg of 1 was established as 0.01% on a 400 MHz instrument and 2% on a 60 MHz (benchtop) NMR spectrometer. Thus, impurities for which quantification is required are readily detected at 400 MHz or above. These results are in contrast to the widespread belief that 1H NMR sensitivity is insufficient for pharmaceutical impurity analysis. The choice of solvent was recognized as a critical parameter for 1H NMR LOD analysis. Furthermore, publicly available NMR raw data (HMDB) proved to be valuable for unveiling the otherwise cryptic information hidden in complex signal patterns via 1H NMR iterative Full Spin Analysis. Finally, the study uncovered the less noticed, yet characteristic, 14N-1H coupling in the -N+(CH3)3 groups, adding strong arguments for the Raw NMR Data Initiative. Collectively, the data prove that the analytical capabilities of high-field NMR easily fulfill the ICH requirements for detection of impurity in the presence of an actual substance of interest which makes it a step closer to achieving regulatory standards.
摘要:
ICH指南建议将药物中常规杂质的阈值报告为0.05%或0.03%(w/w),具体取决于每日最大摄入量。因此,任何适用于杂质分析的仪器分析方法都应能够检测和定量这些水平的分析物。这项研究旨在验证1HNMR光谱对杂质检测的适用性,作为尝试量化之前的第一步。为了减少对设备的需求,这项研究采用了400MHz的仪器进行胆碱(1)和O-(2-羟乙基)胆碱(2)的结构确认和信号分配,已知的杂质。10mg1中2的检测限(LOD)在400MHz仪器上确定为0.01%,在60MHz(台式)NMR光谱仪上确定为2%。因此,需要定量的杂质在400MHz或以上容易检测到。这些结果与普遍认为1HNMR灵敏度不足以用于药物杂质分析的观点相反。溶剂的选择被认为是1HNMRLOD分析的关键参数。此外,公开可用的NMR原始数据(HMDB)被证明对于通过1HNMR迭代全旋转分析揭示隐藏在复杂信号模式中的其他隐秘信息是有价值的。最后,这项研究发现了鲜为人知的,然而有特点的,-N+(CH3)3基团中的14N-1H偶联,为原始核磁共振数据倡议增加了强有力的论据。总的来说,数据证明,高场NMR的分析能力很容易满足ICH在实际感兴趣的物质存在下检测杂质的要求,这使其更接近达到监管标准。