HPLC法测定硝西泮及其片剂中有关物质

目的: 建立反相HPLC同时测定硝西泮原料及片剂中3种杂质的方法。 方法: 采用Venusil XBP C₈柱(250 mm×4.6 mm,5 μm),以20 mmol·L^-1的磷酸二氢钾水溶液-甲醇-四氢呋喃(40∶ 48∶ 12)为流动相,流速1.0 mL·min^-1,检测波长220 nm,柱温30 ℃;进样量10 μL。 结果: 硝西泮与各杂质峰均能良好的分离。杂质A、B、C分别在0.27~15.90 μg·mL^-1,0.25~14.85 μg·mL^-1,0.26~15.40 μg·mL^-1浓度范围内峰面积与浓度成良好的线性关系;高、中、低3个浓度的平均回收率分别为101.2%(RSD为1.9%),99.8%(RSD为1.2%),101.3%(RSD为1.3%);最低检测限分别为0.27,0.25,0.26 ng。 结论: 该方法简便、灵敏,专属性好,可同时测定硝西泮原料和片剂中3种杂质的量。

Objective: Established a reversed-phase HPLC method for the determination of three impurities in nitrazepam and its tablets firstly. Method: The separation was performed on a Venusil XBP C₈(250 mm×4.6 mm,5 μm) column.The mobile phase consisted of 20 mmol·L^-1 potassium dihydrogen phosphate solution-methanol-trehydrofuran (40∶ 48∶ 12),the flow rate was 1.0 mL·min^-1,the column temperature was 30 ℃.The detection wavelength was set at 220 nm.The injection volume was 10 μL. Results: A good separation for nitrazepam and three impurities was achieved.The linear ranges of impurities A,B and C were 0.27-15.90 μg·mL^-1(r=0.9999),0.25-14.85 μg·mL^-1(r=0.9998) and 0.26-15.40 μg·mL^-1(r=0.9997),respectively.The average recoveries of impurities A,B and C at three levels were 101.2% (RSD:1.9%),99.8% (RSD:1.2%) and 101.3% (RSD:1.3%),respectively.The LDLs were 0.27 ng,0.25 ng and 0.26 ng, respectively. Conclusion: The established HPLC method can quantity three impurities in nitrazepam and its tablets simultaneously and accurately.