Peptide therapeutics have exploded in popularity in recent years, motivating the need for advanced manufacturing methods which can be applied across the solid-phase peptide synthesis (SPPS) process. The Food and Drug Administration’s Process Analytical Technology (PAT) initiative offers a platform to implement advanced methods to improve the efficiency and understanding of pharmaceutical manufacturing processes and shows great promise in application toward industrial SPPS. In this work, Raman spectroscopy was used as the main PAT tool to implement methods for on-line and real-time monitoring of the entire SPPS process, from Fmoc removal, to coupling, and through the extensive solvent-washing steps. Raman spectroscopy is a rapid, specific, and nondestructive technique that can provide rich real-time information for SPPS processes and can be used to improve efficiency in solvent use and save process time. Specifically, this work reports on the development of PAT methods for monitoring of amino acid coupling during the coupling stage and residual piperidine concentration during the post-deprotection washing stage of SPPS, to help reduce solvent use and better understand the coupling reaction and its time frame. We show a significant reduction in solvent use is possible by employing Raman spectroscopy along with a partial least squares model to predict the piperidine concentration in real time during continuous wash. In addition, Raman spectroscopy offers a greater understanding of coupling reaction kinetics during SPPS, which could lead to significant improvements in total SPPS process time.

中文翻译：

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优化工业固相肽合成：将拉曼光谱整合为过程分析技术


近年来，肽疗法的普及率呈爆炸式增长，推动了对可应用于固相肽合成 （SPPS） 工艺的先进制造方法的需求。美国食品药品监督管理局 （FDA） 的过程分析技术 （PAT） 计划提供了一个平台，可以实施先进的方法来提高制药过程的效率和理解，并在工业 SPPS 应用中显示出巨大的前景。在这项工作中，拉曼光谱被用作主要的 PAT 工具，用于实施在线和实时监测整个 SPPS 过程的方法，从 Fmoc 去除到耦合，以及通过广泛的溶剂洗涤步骤。拉曼光谱是一种快速、特异、无损的技术，可以为 SPPS 工艺提供丰富的实时信息，可用于提高溶剂使用效率并节省工艺时间。具体来说，这项工作报告了用于监测 SPPS 偶联阶段氨基酸偶联和脱保护后洗涤阶段残留哌啶浓度的 PAT 方法的开发，以帮助减少溶剂使用并更好地了解偶联反应及其时间框架。我们表明，通过使用拉曼光谱和偏最小二乘模型来实时预测连续洗涤过程中的哌啶浓度，可以显著减少溶剂的使用。此外，拉曼光谱可以更好地了解 SPPS 过程中的偶联反应动力学，从而显著缩短 SPPS 总处理时间。