An analytical method was developed for the quantification in plasma of the R and S enantiomers of vigabatrin (VGB), a drug used for the treatment of some refractory pediatric epileptic syndromes. After adding 50 μL of the internal standard, which consisted of a 15 mg/L solution of deuterated racemic VGB, and 100 μL of water to 100 μL of plasma samples, a protein precipitation was performed by adding 600 μL of methanol. The supernatant was evaporated to dryness under a stream of nitrogen and the dry residue was reconstituted with 500 μL of water. Then, 100 μL of 0.01 M o-phthaldialdehyde and 0.01 M N-acetyl-l-cysteine in borate buffer (0.1 M, pH = 9.5) were added for pre-column derivatization of the enantiomers as diastereomeric isoindoles. One microliter of the resulting mixture was injected in the chromatographic system. The chromatographic separation was performed in gradient elution mode at a flow rate of 400 μL/min using a phenomenex EVO C-18 column with a mobile phase composed of 5 mM ammonium acetate and a methanol:acetonitrile (63:37 v/v) mixture. Detection was performed by mass spectrometry in selected reaction monitoring mode using heated electrospray ionization in positive mode as the ion source. Intra- and inter-day precision and accuracy were lower than 15% over the calibration range (0.2–50 mg/L for each enantiomer) and the method was successfully used to assess plasma concentrations of VGB in epileptic children.

开发了一种定量血浆中Vigabatrin（VGB）的R和S对映异构体的分析方法，该药物用于治疗某些难治性小儿癫痫综合征。向100μL血浆样品中添加50μL内标物（由15 mg / L氘化外消旋VGB溶液和100μL水组成）后，通过添加600μL甲醇进行蛋白质沉淀。在氮气流下将上清液蒸发至干，并将干燥的残留物用500μL水重构。然后，将100微升的0.01M的ö -phthaldialdehyde和0.01M Ñ乙酰基升加入在硼酸盐缓冲液（0.1 M，pH = 9.5）中的-半胱氨酸用于对映体的柱前衍生，以非对映异构体的异吲哚形式。将一微升所得混合物注入色谱系统。使用phenomenex EVO C-18色谱柱以400μL/ min的流速以梯度洗脱模式进行色谱分离，该色谱柱的流动相为5 mM乙酸铵和甲醇：乙腈（63:37 v / v）混合物。使用正模式下的加热电喷雾电离作为离子源，在选定的反应监测模式下通过质谱仪进行检测。在校准范围内（每种对映体，日间和日间精度和准确度均低于15％），该方法已成功用于评估癫痫患儿的血浆VGB浓度。