Analytical Sciences, GlaxoSmithKline Pharmaceutical R&D, 709 Swedeland Road, King of Prussia, PA 19406, USA.
J Pharm Biomed Anal. 2010 May 1;52(1):30-6. doi: 10.1016/j.jpba.2009.11.027. Epub 2009 Dec 1.
Trace analysis of unstable and reactive pharmaceutical genotoxic impurities (GTIs) is a challenging task in pharmaceutical analysis. Many method issues such as insufficient sensitivity, poor precision, and unusual (too high/low) spiking recovery are often directly related to analytes' instability. We report herein a matrix deactivation approach that chemically stabilizes these analytes for analytical method development. In contrast to the conventional chemical derivatization approach where the analytes are transformed into stable detectable species, the matrix deactivation approach chemically deactivates the hypothetical reactive species in the sample matrix. The matrix deactivation approach was developed on the premise that the instability of certain analytes at trace level is caused by reactions between the analytes and low level reactive species in the sample matrix. Thus, quenching the reactivity of the reactive species would be a key to stabilizing the unstable and reactive analytes. For example, electrophilic alkylators could be destabilized by nucleophiles or bases through either nucleophilic substitution or elimination reactions. One way to mask those reactive species is via protonation by adding acids to the diluent. Alternatively, one can use nucleophile scavengers to deplete reactive unknown species in the sample matrix completely, in analogy to the use of antioxidants and metal chelators to prevent oxidation in the analysis of compounds liable to oxidation. This paper reports the application of the matrix deactivation to the analyses of unstable and reactive pharmaceutical genotoxic impurities. Some of the methods have been used to support development of manufacturing processes for drug substances and a recent regulatory filing.
不稳定和反应性药物遗传毒性杂质 (GTIs) 的痕量分析是药物分析中的一项具有挑战性的任务。许多方法问题，如灵敏度不足、精密度差以及不寻常（过高/过低）的加标回收率，通常与分析物的不稳定性直接相关。我们在此报告了一种基质失活方法，该方法可用于化学稳定这些分析物以开发分析方法。与传统的化学衍生化方法不同，该方法将分析物转化为稳定的可检测物质，而基质失活方法则通过化学方式使样品基质中的假设反应性物质失活。该基质失活方法是基于以下前提开发的：在痕量水平下，某些分析物的不稳定性是由于分析物与样品基质中低水平反应性物质之间的反应引起的。因此，抑制反应性物质的反应性是稳定不稳定和反应性分析物的关键。例如，亲电性烷基化剂可以通过亲核取代或消除反应被亲核试剂或碱破坏稳定性。一种掩蔽这些反应性物质的方法是通过向稀释剂中添加酸进行质子化。或者，可以使用亲核试剂清除剂完全耗尽样品基质中的反应性未知物质，类似于使用抗氧化剂和金属螯合剂来防止易氧化化合物的分析中的氧化。本文报道了基质失活在不稳定和反应性药物遗传毒性杂质分析中的应用。其中一些方法已用于支持药物物质制造工艺的开发，并已用于最近的法规申报。
