School of Xiangya Pharmaceutical Sciences, Central South University, Changsha, Hunan, China.
The First affiliated hospital, School of Medicine, Xiamen university, Xiamen, Fujian, China.
Biomed Chromatogr. 2020 Oct;34(10):e4927. doi: 10.1002/bmc.4927. Epub 2020 Jul 7.
A sensitive and selective high-performance liquid chromatography-tandam mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous quantification of sildenafil and its metabolite N-desmethyl sildenafil in human plasma. Sildenafil-d8 was used as an internal standard. The analytes were extracted by precipitation extraction and chromatographed on a C column using mobile phase A of water (containing 0.1% formic acid) and mobile phase B of acetonitrile (containing 0.1% formic acid) with gradient elution. Quantification was done using multiple reaction monitoring mode to monitor the precursor-to-product ion transitions of m/z 475.4 → m/z 283.3 for sildenafil, m/z 461.4 → m/z 283.2 for N-desmethyl sildenafil and m/z 483.3 → m/z 108.1 for IS in positive ionization mode. The calibration curve was established over the range of 2.00-1,000 ng/ml and the correlation coefficient was >0.99. The intra-day and inter-day relative standard deviations were <6.5% for sildenafil and 6.3% for N-desmethyl sildenafil respectively. Accuracy determinaed at four concentrations was 86.50-105.67% for sildenafil and 96.83-114.40% for N-desmethyl sildenafil. This method was successfully applied to a pharmacokinetic description of sildenafil and the effect of food intake on the pharmacokinetics of sildenafil was also demonstrated in healthy Chinese volunteers.
建立并验证了一种灵敏、专属性的高效液相色谱-串联质谱（LC-MS/MS）法，用于同时定量测定人血浆中的西地那非及其代谢物 N-去甲基西地那非。以西地那非-d8 为内标。采用沉淀萃取法提取分析物，在 C 柱上，以水（含 0.1%甲酸）为流动相 A 和乙腈（含 0.1%甲酸）为流动相 B，进行梯度洗脱。采用多反应监测模式定量，监测 m/z 475.4→m/z 283.3（西地那非）、m/z 461.4→m/z 283.2（N-去甲基西地那非）和 m/z 483.3→m/z 108.1（IS）的前体-产物离子跃迁，在正离子化模式下进行。校准曲线范围为 2.00-1000ng/ml，相关系数>0.99。日内和日间相对标准差（RSD）分别小于 6.5%（西地那非）和 6.3%（N-去甲基西地那非）。在四个浓度下的准确度测定结果显示，西地那非的准确度为 86.50-105.67%，N-去甲基西地那非的准确度为 96.83-114.40%。该方法成功应用于西地那非的药代动力学描述，并在健康中国志愿者中证实了饮食对西地那非药代动力学的影响。
