Bartek M J, Mayol R F, Boarman M P, Gammans R E, Gallo D G
Department of Metabolism and Pharmacokinetics, Bristol-Myers Company, Evansville, Indiana.
Ther Drug Monit. 1988;10(4):446-52. doi: 10.1097/00007691-198804000-00012.
A high performance liquid chromatography (HPLC) method for the quantification of encainide (4-methoxy-2'-[2-(1-methyl-2-piperidinyl)-ethyl]benzanilide hydrochloride) in plasma and urine has been developed and validated. Encainide and two metabolites, the O-demethyl (ODE) and 3-methoxy-O-demethyl (MODE) congeners of the drug, can be quantified simultaneously in plasma and urine by this procedure. The compounds are extracted from buffered plasma (pH 8.5) using N-butyl chloride containing 5% (vol/vol) isopropyl alcohol. The compounds are then separated on a silica column using ethanol:water:methanesulfonic acid, 500/60/0.2 (vol/vol/vol) as the mobile phase and quantified by measuring their UV absorbance at 254 nm. The lower limit of detection for the analytes was 5 ng/ml in plasma and 25 ng/ml in urine. The method was linear from 5 to 5,000 ng/ml for plasma and 25 to 5,000 ng/ml for urine. The intra-assay precision of the method for encainide, ODE, and MODE in plasma and urine ranged from 2 to 8% RSD depending upon concentration. The inter-assay precision of the method was less than 6% for the three analytes per ml of plasma and urine. Absolute recovery of the analytes from plasma ranged from 82 to 92%, while recoveries from urine ranged from 83 to 99%. The analytes were shown to be stable in frozen plasma and urine for up to 52 weeks.
已开发并验证了一种用于定量测定血浆和尿液中恩卡尼（盐酸4-甲氧基-2'-[2-(1-甲基-2-哌啶基)乙基]苯甲酰胺）的高效液相色谱（HPLC）方法。通过该程序可同时定量测定血浆和尿液中的恩卡尼及其两种代谢物，即该药物的O-去甲基（ODE）和3-甲氧基-O-去甲基（MODE）同系物。使用含5%（体积/体积）异丙醇的正丁基氯从缓冲血浆（pH 8.5）中提取这些化合物。然后，使用乙醇:水:甲磺酸，500/60/0.2（体积/体积/体积）作为流动相，在硅胶柱上分离这些化合物，并通过测量其在254 nm处的紫外吸光度进行定量。分析物在血浆中的检测下限为5 ng/ml，在尿液中的检测下限为25 ng/ml。该方法在血浆中5至5000 ng/ml以及在尿液中25至5000 ng/ml范围内呈线性。该方法在血浆和尿液中对恩卡尼、ODE和MODE的批内精密度根据浓度不同，相对标准偏差（RSD）范围为2%至8%。该方法对每毫升血浆和尿液中三种分析物的批间精密度小于6%。分析物从血浆中的绝对回收率范围为82%至92%，而从尿液中的回收率范围为83%至99%。分析物在冷冻血浆和尿液中最多可稳定保存52周。
