Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, 24 Tongjia lane, Nanjing 210009, China; Key Laboratory of Drug Consistency Evaluation, China Pharmaceutical University, Nanjing 210009, China.
Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, 24 Tongjia lane, Nanjing 210009, China; Key Laboratory of Drug Consistency Evaluation, China Pharmaceutical University, Nanjing 210009, China; State Key Laboratory of Natural Medicine, China Pharmaceutical University, Nanjing 210009, China.
J Pharm Biomed Anal. 2018 Sep 5;158:74-81. doi: 10.1016/j.jpba.2018.05.037. Epub 2018 May 25.
A rapid and sensitive method was established to determine amlodipine enantiomers using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Stereoselective separation was performed on CHIRALCEL OZ-RH column (150 mm × 4.6 mm i.d., 5 μm) with acetonitrile-water (10 mM ammonium acetate, 0.5% ammonia solution) (95:5, v/v) at a flow rate of 0.5 mL/min. The substances were detected by mass spectrometer equipped with an electrospray ionization source interface in positive ion mode. Multiple reaction monitoring was selected with the transition of the m/z 409.1 → 238.0 for amlodipine enantiomers and m/z 237.0 → 194.1 for carbamazepine (IS) respectively. Calibration curves were linear at the range of 0.9375-120 ng/mL for both isomers with r > 0.99, while using a lower sample volume (50 μL) compared with previously reported enantiospecific methods The accuracy was at the range of 84.1-119.0% for R-amlodipine, and 87.4-118.2% for S-amlodipine, respectively. The within- and between-run precision (CV%) was within 10% in all cases for both enantiomers. Enantiomers were stable under different conditions, e.g. processed sample, short-term, residue, long-term and freeze/thaw. The LC-MS/MS method was successfully applied in pharmacokinetic study of amlodipine enantiomers in rats. It was observed the concentration of the S- amlodipine was significantly higher than that of the R-amlodipine in racemate-treated group. And there was no significant difference in the pharmacokinetic profiles of the S-amlodipine between the 10 mg/kg racemate- and 5 mg/kg S-amlodipine-treated groups. In addition, it was the first time to find that the main pharmacokinetic parameters (AUC, AUC and C) of R-amlodipine were significantly lower in the 5 mg/kg R-amlodipine-treated group compared with the racemate-treated group.
建立了一种采用液相色谱-串联质谱法（LC-MS/MS）测定氨氯地平对映异构体的快速灵敏方法。手性柱（CHIRALCEL OZ-RH 柱，150mm×4.6mm i.d.，5μm）上以乙腈-水（10mM 乙酸铵，0.5%氨溶液）（95:5，v/v）为流动相，流速为 0.5mL/min 进行立体选择性分离。采用电喷雾电离源接口的质谱仪在正离子模式下检测物质。选择 m/z 409.1→238.0 用于氨氯地平对映异构体和 m/z 237.0→194.1 用于卡马西平（IS）的多重反应监测。两种异构体的校准曲线均呈线性，范围为 0.9375-120ng/mL，r＞0.99，而与之前报道的对映选择性方法相比，所用样品量较低（50μL）。R-氨氯地平的准确度在 84.1-119.0%范围内，S-氨氯地平的准确度在 87.4-118.2%范围内。两种对映异构体在所有情况下的日内和日间精密度（CV%）均在 10%以内。对映异构体在不同条件下稳定，如处理样品、短期、残留、长期和冻融。该 LC-MS/MS 方法成功应用于大鼠氨氯地平对映体的药代动力学研究。结果表明，在消旋体处理组中，S-氨氯地平的浓度明显高于 R-氨氯地平。在 10mg/kg 消旋体和 5mg/kg S-氨氯地平处理组之间，S-氨氯地平的药代动力学特征无显著差异。此外，这是首次发现与消旋体处理组相比，5mg/kg R-氨氯地平处理组 R-氨氯地平的主要药代动力学参数（AUC、AUC 和 C）显著降低。
