高效液相色谱法同时测定盐酸维拉帕米及其主要代谢产物

建立了反相高效液相色谱法同时测定人血浆中维拉帕米及其主要代谢产物去甲维拉帕米血药浓度.以甲醇—水—三乙胺(67∶33∶0.4,pH6.7)为流动相,乙吗噻嗪(ethmosine)为内标,样品用正己烷—正丁醇混合液提取浓缩后进样,紫外检测器检测(279nm)。此法操作简便,精密度好,日内、日间误差:维拉帕米<8.6%,去甲维拉帕米<7.6%;方法回收率高,维拉帕米、去甲维拉帕米回收率均>92%。两者血药浓度在25～1000ng·ml-1范围内呈线性关系,最小检测浓度维拉帕米:2.5ng·ml^-1,去甲维拉帕米:5.0ng·ml^-1。应用该法测定了6名志愿者口服盐酸维拉帕米片剂后的血药浓度。

SIMULTANEOUS DETERMINATION OF VERAPAMIL AND ITS MAJOR METABOLITE IN HUMAN PLASMA BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

A sensitive high-performance liquid chromatographic assay suitable for thesimultaneous determination of verapamil(Ⅰ)and its major active metabolite norverapamil(Ⅱ)inhuman plasma is described. After adding internal standard ethmosine, plasma samples were extractedusing a mixture of n-hexane and n-butyl alcohol(12 ∶ 1)to give mean recoveries of>92%of bothⅠ, and Ⅱ. The extracts were chromatographed on a C₁₈ reversed phase column with a mobile phasecompcosed of methanol,water and triethylamine(67 ∶ 33 ∶0.4,pH 6.7), with UV(λ,279 nm)detection. The calibration curves were linear over a wide range of concentrations(25～1000ng·ml^-1), and the limits of determination was 2.5 ng·ml^-1 for Ⅰ and 5.0 ng·ml-1 for Ⅱ. Themethod showed good precision: the within-day RSD were <7.6%for both Ⅰ and Ⅱ; the day-to～dayRSD were <8.6%for beth Ⅰ and Ⅱ.Using this assay, plasma concentrdtions of both Ⅰ and Ⅱ weresimultaneously determined in six volunteers after a single oral dose of 120 mg of verapamil· HCl.