Division of Pharmaceutics and Pharmaceutical Chemistry, College of Pharmacy, The Ohio State University, Columbus, OH, USA.
Division of Pharmacy Practice and Science, College of Pharmacy, The Ohio State University, Columbus, OH, USA.
J Pharm Biomed Anal. 2019 Aug 5;172:183-188. doi: 10.1016/j.jpba.2019.04.041. Epub 2019 Apr 19.
A novel method using UPLC with tandem mass-spectrometric detection (UPLC-MS/MS) with positive electrospray ionization was developed for the detection of the antiarrhythmic drug, dofetilide, in mouse plasma and urine. Protein precipitation was performed on 10 μL of plasma and 2 μL of urine samples using dofetilide-D4 as an internal standard, and separation of the analyte was accomplished on a C18 analytical column with the flow of 0.40 mL/min. Subsequently, the method was successfully applied to determine the pharmacokinetic parameters of dofetilide following oral and intravenous administration. The calibration curve was linear over the selected concentration range (R ≥ 0.99), with a lower limit of quantitation of 5 ng/mL. The intra-day and inter-day precisions, and accuracies obtained from a 5-day validation ranged from 3.00 to 7.10%, 3.80-7.20%, and 93.0-106% for plasma, and 3.50-9.00%, 3.70-10.0%, 87.0-106% for urine, while the recovery of dofetilide was 93.7% and 97.4% in plasma and urine, respectively. The observed pharmacokinetic profiles revealed that absorption is the rate-limiting step in dofetilide distribution and elimination. Pharmacokinetic studies illustrate that the absolute bioavailability of dofetilide in the FVB strain mice is 34.5%. The current developed method allows for accurate and precise quantification of dofetilide in micro-volumes of plasma and urine, and was found to be suitable for supporting in vivo pharmacokinetic studies.
建立了一种利用超高效液相色谱-串联质谱联用技术（UPLC-MS/MS），采用正电喷雾电离法，检测抗心律失常药物多非利特在小鼠血浆和尿液中的新型方法。采用多非利特-D4 作为内标，对 10μL 血浆和 2μL 尿液样品进行蛋白沉淀，用 C18 分析柱以 0.40mL/min 的流速进行分离。随后，该方法成功应用于口服和静脉给药后多非利特的药代动力学参数的测定。校准曲线在选定的浓度范围内呈线性（R≥0.99），定量下限为 5ng/mL。5 天验证期间，从血浆获得的日内和日间精密度和准确度分别为 3.00-7.10%、3.80-7.20%和 93.0-106%，从尿液获得的分别为 3.50-9.00%、3.70-10.0%和 87.0-106%，而多非利特在血浆和尿液中的回收率分别为 93.7%和 97.4%。观察到的药代动力学特征表明，吸收是多非利特分布和消除的限速步骤。药代动力学研究表明，FVB 品系小鼠多非利特的绝对生物利用度为 34.5%。本研究开发的方法可以准确、精密地定量分析微体积血浆和尿液中的多非利特，适合支持体内药代动力学研究。
