Background Levofloxacin is a third-generation fluoroquinolone that has several advantages over its (R) ofloxacin isomer. It is used to treat different types of infection, including urinary infection and prostatitis. Objective A new HPLC method for the enantioselective separation of levofloxacin and its chiral impurity was developed and validated to improve the separation of the enantiomers of levofloxacin [impurity(R) and active principle (S)] by increasing the value of the resolution between the eutomer and the distomer. Method Chromatographic separation was performed on a Prodigy ODS -2, 5 µm 4.6 × 150 mm column, with a gradient of buffer solution and methanol (80:20, v/v). A Box–Behnken design was considered when optimizing the enantioseparation involving the effects of many factors such as the concentration of d-phenylalanine, the pH of the buffer, the percentage of organic modifier in the mobile phase, the flow rate, the temperature of the column, and the type of column. Results Chiral separation was achieved with an optimal resolution of 3.8. The method was successfully validated following the International Conference on Harmonization Q2 (R1) guideline, fulfilling the acceptance criteria for selectivity [no interference in the retention time of (S) levofloxacin and (R) levofloxacin], linearity (r ≥0.999 in the range 1.25–3.75 µg/mL for all enantiomers), and precision (RSD <2%). Accuracy was assessed by the application of the analytical method to an analyte of known purity, providing evidence for the usefulness of this monitoring system. Conclusions The method was successfully used for the determination of levofloxacin impurity in raw material and pharmaceutical dosage forms. Highlights The following method is accurate and robust to quantify and characterize the presence of levofloxacin impurity in raw material for pharmaceutical compounds.

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左氧氟沙星及其手性杂质对映选择性分离的配体交换色谱法优化

背景 左氧氟沙星是第三代氟喹诺酮类药物，与 (R) 氧氟沙星异构体相比，它具有多项优势。它用于治疗不同类型的感染，包括泌尿系统感染和前列腺炎。目的 开发并验证一种新的左氧氟沙星及其手性杂质的对映选择性分离高效液相色谱方法，通过提高左氧氟沙星对映异构体[杂质(R)和活性成分(S)]的分离度来改善左氧氟沙星对映异构体的分离。和 distomer。方法 在 Prodigy ODS -2, 5 µm 4.6 × 150 mm 色谱柱上进行色谱分离，采用缓冲溶液和甲醇梯度 (80:20, v/v)。在优化对映体分离时考虑了 Box-Behnken 设计，其中涉及许多因素的影响，例如 d-苯丙氨酸的浓度，缓冲液的 pH 值、流动相中有机改性剂的百分比、流速、柱温和柱类型。结果 以 3.8 的最佳分辨率实现了手性分离。该方法成功地按照国际协调会议 Q2 (R1) 指南进行了验证，满足选择性的接受标准 [不干扰 (S) 左氧氟沙星和 (R) 左氧氟沙星的保留时间]、线性 (r ≥0.999 在范围内所有对映体为 1.25–3.75 µg/mL）和精密度（RSD <2%）。通过将分析方法应用于已知纯度的分析物来评估准确性，为该监测系统的有用性提供证据。结论该方法成功地用于原料药和药物剂型中左氧氟沙星杂质的测定。亮点 以下方法准确且稳健，可定量和表征药物化合物原料中存在的左氧氟沙星杂质。