Background:Minodronic acid (MA) is a third-generation nitrogen-containing heterocyclicbisphosphonate used to treat osteoporosis. In the process of starting materials researchand preparation, the key intermediate impurities and degradation impurities have a great impacton the quality control of the drug.Objective:A sensitive, reliable, high-performance liquid chromatography (HPLC) method wasdeveloped and validated for the quantitative determination of MA and its related impurities (atotal of 6 compounds, including 2 new impurities).Methods:The separation was achieved on an InertSustain ODS-4 C18 (250 mm × 4.6 mm, 5μm) column using the mixture of 0.01 mol/L sodium pyrophosphate and 1 mmol tetrabutylammoniumphosphate (the mobile phase pH was adjusted to 7.80 by phosphonic acid).Results:The quantitative analytical method was fully validated with respect to linearity (r >0.999), sensitivity (limit of detection < 35 ng/mL), precision, accuracy (the recovery was between98.7% and 104.2%), and robustness. Six process-related impurities in Minodronic Acid(MA) bulk drug were determined by high-performance liquid chromatography (HPLC). Furthermore,except for two starting materials, other four impurities were identified and characterizedas 2-(imidazo[1,2-a] pyridin-3-yl) ethyl acetate (Imp-C), 2-(imidazo [1,2-a] pyridin- 3-yl)acetic acid (Imp-D), 3-(2-hydroxy-2,2- diphosphonoethyl)-4H-imidazo [1,2-a] pyridine -4-oxide (Imp-E) and 2,5- Dihydroxy- 3,6-bis(imidazo[1,2-a] pyridine-3-yl methyl) -2,5-dioxo-1,4,2,5- dioxoDiphosphonium-3,6-diyl) bisphosphonic acid (Imp-F) using liquid chromatograph-mass spectrometer (LC-MS), MS/MS, Infrared Radiation and Nuclear Magnetic Resonancespectroscopy (1H-NMR and 13C-NMR). To the best of our knowledge, two of them (Imp-E and Imp-F) are new compounds and have not been reported previously.Conclusion:The HPLC method was developed and optimized, which could be applied forquantitative detection of the impurities, and further quality evaluation of MA.

中文翻译：

---

米诺膦酸原料药中工艺相关杂质的鉴定、表征和测定

背景：米诺膦酸（MA）是第三代含氮杂环双膦酸盐，用于治疗骨质疏松症。在起始原料研究和制备过程中，关键中间体杂质和降解杂质对药物的质量控制有很大影响。 MA 及其相关杂质（共 6 种化合物，包括 2 种新杂质）。方法：在 InertSustain ODS-4 C18 (250 mm × 4.6 mm, 5 μm) 色谱柱上使用 0.01 mol/L 钠的混合物进行分离焦磷酸盐和1 mmol磷酸四丁铵（流动相pH用膦酸调节至7.80）。 结果：定量分析方法在线性 (r >0.999)、灵敏度（检测限 < 35 ng/mL）、精密度、准确度（回收率在 98.7% 和 104.2% 之间）和稳健性方面得到了充分验证。采用高效液相色谱法 (HPLC) 测定了米诺膦酸 (MA) 原料药中的六种工艺相关杂质。此外，除两种起始原料外，其他四种杂质被鉴定和表征为2-(咪唑并[1,2-a]吡啶-3-基)乙酸乙酯(Imp-C)、2-(咪唑[1,2-a] ] 吡啶-3-基）乙酸（Imp-D）、3-（2-羟基-2,2-二膦酰基乙基）-4H-咪唑并[1,2-a]吡啶-4-氧化物（Imp-E）和2,5- 二羟基- 3,6-双（咪唑并[1,2-a] 吡啶-3-基甲基）-2,5-dioxo-1,4,2,5- dioxoDiphosphonium-3,6-diyl）双膦酸 (Imp-F) 使用液相色谱-质谱仪 (LC-MS)、MS/MS、红外辐射和核磁共振光谱（1H-NMR 和 13C-NMR）。据我们所知，其中两种（Imp-E和Imp-F）是新化合物，以前没有报道过。结论：开发并优化了HPLC方法，可用于杂质的定量检测，并且MA的进一步质量评估。