目的 建立依普利酮含量和有关物质的反相高效液相色谱测定方法。方法 色谱柱为Agilent Poroshell色谱柱(4.6 mm×100 mm,2.7 μm),流动相为0.1%磷酸溶液-乙腈-甲醇(64∶18∶18),流速为1.0 mL·min^-1,检测波长为240 nm;稀释剂为水-乙腈-甲醇(50∶25∶25)。结果 有关物质:依普利酮峰与其他杂质峰可以良好分离;依普利酮、中间体Ⅲ和Ⅳ、有关物质A～E的检测限分别为0.03、0.13、0.25、0.05、0.05、0.26、0.07和0.12 ng,定量限分别为0.12、0.42、0.84、0.18、0.18、0.86、0.22和0.41 ng;依普利酮和有关物质A～E分别在0.13～1.53、0.25～3.03、0.25～2.99、0.13～1.61、0.14～1.63和0.13～1.54 μg·mL^-1内线性关系良好(r=0.999 9,n=7),且有关物质A～E相对依普利酮的校正因子均在0.90～1.10之间;有关物质A～E的平均加样回收率(n=9)均在95.0%～105.0%之间。含量测定:依普利酮在12.60～75.63 μg·mL^-1内线性关系良好(r=0.999 6,n=6),且重复性好(RSD=0.19%,n=6)。结论 本法简便、灵敏度高、专属性强、准确度和精密度好,可以用于依普利酮含量和有关物质测定。

OBJECTIVE To establish an RP-HPLC method for determination of the contents of eplerenone and its related substances. METHODS A RP-HPLC method was developed by using a C₁₈ column (Agilent Poroshell,4.6 mm×100 mm, 2.7 μm), the mobile phase consisted of H₂O-CH₃CN-MeOH (64∶18∶18), the flow rate was 1.0 mL·min^-1, and the detection wavelength was set at 240 nm. The diluent was H₂O-CH₃CN-MeOH (50∶25∶25). RESULTS Eplerenone was well separated from the impurities. For the determination of related substances, the LODs of eplerenone, its intermediate (Ⅲ and Ⅳ) and related substances (A-E) were 0.03, 0.13, 0.25, 0.05, 0.05, 0.26, 0.07 and 0.12 ng, and the LOQs were 0.12, 0.42, 0.84, 0.18, 0.18, 0.86, 0.22 and 0.41 ng, respectively. The calibration curves of eplerenone and related substances (A-E) had good linear relationship within 0.13-1.53, 0.25-3.03, 0.25-2.99, 0.13-1.61, 0.14-1.63, and 0.13-1.54 μg·mL^-1(r=0.999 9, n=7), and the correction factors of the related substances (A-E) were all in the range of 0.90-1.10. The average recoveries of the related substances (A-E) were all within 95.0%-105.0% (n=9). For the content determination of eplerenone, the validation test showed good linearity over the range of 12.60-75.63 μg·mL^-1 (r=0.999 6, n=6) with good repeatability (RSD=0.19%, n=6). CONCLUSION The developed method proves to be simple, accurate, specific and reliable. It can be applied to the determination of eplerenone and its related substances.