In this work, two chromatographic methods are developed and validated for the determination of enrofloxacin and bromhexine (BRM) HCl in the presence of two of their specified impurities, ciprofloxacin and BRM impurity C. The suggested chromatographic methods included the use of thin layer chromatography (TLC-densitometry) and high-performance liquid chromatography (HPLC). In case of TLC-densitometry, good separation was achieved by using mobile phase of n.butanol:acetone:water:glacial acetic acid:triethylamine (10:3:1:0.5:0.5, by volume) on silica gel stationary phase at 254-nm detection. The developed HPLC method used BDS HYPERSIL C18 column with a mobile phase of water:acetonitrile:methanol:triflouroacetic acid. A linear gradient elution of 75–10%, 20–50% and 5–40% for water, acetonitrile and methanol, respectively, was applied in 13 min at a flow rate of 1.5 mL min−1. These methods were sufficient to separate the four substances simultaneously, and they are validated as per International Conference on Harmonization guidelines.

中文翻译：

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正相 TLC 和梯度反相 HPLC 同时测定恩诺沙星和盐酸溴己新（存在两种官方杂质）

在这项工作中，开发并验证了两种色谱方法，用于在两种指定杂质（环丙沙星和 BRM 杂质 C）存在下测定恩诺沙星和盐酸溴己新 (BRM)。建议的色谱方法包括使用薄层色谱法（ TLC-密度测定法）和高效液相色谱法（HPLC）。在薄层色谱密度测定中，使用正丁醇：丙酮：水：冰醋酸：三乙胺（10：3：1：0.5：0.5，体积比）流动相在硅胶固定相上，254 ℃下可实现良好的分离。 -纳米检测。所开发的HPLC方法使用BDS HYPERSIL C18柱，流动相为水：乙腈：甲醇：三氟乙酸。水、乙腈和甲醇分别以 75-10%、20-50% 和 5-40% 的线性梯度洗脱，以 1.5 mL min−1 的流速在 13 分钟内进行。这些方法足以同时分离四种物质，并且根据国际协调会议指南对它们进行了验证。