Engelbrecht Lynette, Grobler C J, Rheeders Malie
Clinical Pharmacokinetic Laboratory, School of Pharmacy (Pharmacology), North West University, Potchefstroom, South Africa.
Department of Health Sciences, Vaal University of Technology, Vanderbijlpark, South Africa.
Biomed Chromatogr. 2017 Oct;31(10). doi: 10.1002/bmc.3969. Epub 2017 Apr 20.
A simple, fast and cost-effective method was developed and validated for the determination of levetiracetam (LEV) in plasma/serum of patients using high performance liquid chromatography (HPLC) with ultraviolet detection. The stability of LEV plasma/serum samples over time and in different blood collection tubes was evaluated. Serum/plasma samples were deproteinized by methanol spiked with the internal standard, gabapentin. HPLC was carried out on a Venusil XBP C , 250 × 4.6 mm, 5 μm column, at a flow rate of 1.0 mL/min and with mobile phase consisting of 50 mm potassium dihydrogen phosphate-acetonitrile at a pH of 5.5. The UV detector was set at 205 nm and 10 μL was injected. Total runtime was 15 min. Calibration curves were linear (correlation coefficient = 0.999) over a concentration range of 1-60 μg/mL. Relative standard deviation values for both the inter-day and intra-day precision and accuracy were <5% for the concentration range. The influence of different collection tubes and the effect of time on the stability of LEV was investigated. These factors may cause inaccuracies owing to drug-protein binding and interference in the matrix. This method is simple, fast, cost-effective, reliable and accurate with minimal sample preparation for daily routine use in therapeutic drug monitoring.
开发并验证了一种简单、快速且经济高效的方法，用于使用带紫外检测的高效液相色谱法（HPLC）测定患者血浆/血清中的左乙拉西坦（LEV）。评估了LEV血浆/血清样品随时间以及在不同采血管中的稳定性。血清/血浆样品用添加了内标加巴喷丁的甲醇进行脱蛋白处理。HPLC在Venusil XBP C 250×4.6 mm、5μm柱上进行，流速为1.0 mL/min，流动相由pH值为5.5的50 mM磷酸二氢钾-乙腈组成。紫外检测器设置在205 nm，进样量为10μL。总运行时间为15分钟。校准曲线在1 - 60μg/mL的浓度范围内呈线性（相关系数 = 0.999）。该浓度范围内日间和日内精密度及准确度的相对标准偏差值均<5%。研究了不同采血管的影响以及时间对LEV稳定性的影响。这些因素可能由于药物 - 蛋白质结合和基质干扰而导致不准确。该方法简单、快速、经济高效、可靠且准确，样品制备最少，可用于治疗药物监测的日常常规使用。
