在这项研究中,根据药物杂质分析评估了温度响应×反相液相色谱(TRLC×RPLC)的可能性。由于他们提供的单位时间峰值容量增加,二维LC方法正与复杂药物制剂的分析相关。因为后者描述了杂质数量增加的更大倾向,目前的1D-HPLC方法往往被证明是不够的。由于许多LC×LC方法受到调制的限制,溶剂相容性,正交性,和敏感性问题,在这项工作中,探索了TRLC×RPLC的组合用于药物杂质分析。由于纯水性分离与RPLC的这种组合允许在第二维度进行系统和无优化的重新聚焦,它为通用LC×LC打开了可能性,需要最少的方法开发,以这种方式克服了LC×LC的当代主要障碍。该方法用包含11种皮质类固醇和6种孕激素的17种溶质的代表性混合物证明。在三个RP核-壳色谱柱选择性(PoroshellEC-C18,苯基-己基和PFP)上评估了正交性和峰容量。尽管TRLC×EC-C18组合提供了更好的正交性,与PFP色谱柱的结合被证明是手边分离的最佳选择。根据混合物的组成,使用充分,shifted,或分段梯度允许分离的简单优化。与选定的主要化合物相比,开发的平台允许检测0.05%水平的杂质,同时也为分析包含两种活性成分的制剂开辟了可能性。
In this study, the possibilities of temperature responsive × reversed phase liquid chromatography (TRLC × RPLC) are assessed in terms of pharmaceutical impurity analysis. Due to the increased peak capacity per unit time they offer, two-dimensional LC approaches are gaining relevance for the analysis of complex drug formulations. Because the latter depicts a larger predisposition for the occurrence of an increased number of impurities, current 1D-HPLC approaches often prove insufficient. Since many LC × LC methods are limited by modulation, solvent compatibility, orthogonality, and sensitivity issues, the combination of TRLC × RPLC is explored in this work for pharmaceutical impurity analysis. As this combination of a purely aqueous separation with RPLC allows for systematic and optimization-free refocusing in the second dimension, it opens possibilities for generic LC × LC requiring minimal to no method development, in this way overcoming a major perceived contemporary hurdle of LC × LC. The approach is demonstrated with a representative mixture of 17 solutes comprising 11 corticosteroids and 6 progestogens. Orthogonality and peak capacities were assessed on three RP core-shell column selectivities (Poroshell EC-C18, phenyl-hexyl and PFP). Although the TRLC × EC-C18 combination offered somewhat better orthogonality, the combination with the PFP column proved the best for the separation at hand. Depending on the composition of the mixture, the use of full, shifted, or segmented gradients allowed facile optimization of the separation. The developed platform allowed detection of the impurities at the 0.05% level compared to a selected main compound, while also opening up possibilities for analysis of formulations comprising two active ingredients.