Alcantara Greyce Kelly Steinhorst, Calixto Leandro Augusto, de Moraes Luiz Alberto Beraldo, Queiroz Regina Helena Costa, de Oliveira Anderson Rodrigo Moraes, de Gaitani Cristiane Masetto
Department of Pharmaceutical Sciences, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, 14040-903 Ribeirão Preto, SP, Brazil.
Department of Exact and Earth Sciences, Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of São Paulo, 09972-270 Diadema, SP, Brazil.
J Anal Methods Chem. 2016;2016:5976324. doi: 10.1155/2016/5976324. Epub 2016 Oct 17.
Levetiracetam (LEV) is an antiepileptic drug that is clinically effective in generalized and partial epilepsy syndromes. The use of this drug has been increasing in clinical practice and intra- or -interindividual variability has been exhibited for special population. For this reason, bioanalytical methods are required for drug monitoring in biological matrices. So this work presents a dispersive liquid-liquid microextraction method followed by gas chromatography-mass spectrometry (DLLME-GC-MS) for LEV quantification in human plasma. However, due to the matrix complexity a previous purification step is required. Unlike other pretreatment techniques presented in the literature, for the first time, a procedure employing ultrafiltration tubes Amicon® (10 kDa porous size) without organic solvent consumption was developed. GC-MS analyses were carried out using a linear temperature program, capillary fused silica column, and helium as the carrier gas. DLLME optimized parameters were type and volume of extraction and dispersing solvents, salt addition, and vortex agitation time. Under chosen parameters (extraction solvent: chloroform, 130 L; dispersing solvent: isopropyl alcohol, 400 L; no salt addition and no vortex agitation time), the method was completely validated and all parameters were in agreement with the literature recommendations. LEV was quantified in patient's plasma sample using less than 550 L of organic solvent.
左乙拉西坦（LEV）是一种抗癫痫药物，在全身性和部分性癫痫综合征中具有临床疗效。该药物在临床实践中的使用一直在增加，并且特殊人群已表现出个体内或个体间的变异性。因此，需要生物分析方法来监测生物基质中的药物。所以这项工作提出了一种分散液液微萃取方法，随后采用气相色谱 - 质谱联用（DLLME - GC - MS）对人血浆中的左乙拉西坦进行定量。然而，由于基质复杂性，需要一个先前的纯化步骤。与文献中提出的其他预处理技术不同，首次开发了一种使用Amicon®超滤管（孔径10 kDa）且不消耗有机溶剂的方法。气相色谱 - 质谱联用分析使用线性温度程序、毛细管熔融石英柱和氦气作为载气进行。分散液液微萃取的优化参数包括萃取和分散溶剂的类型及体积、加盐量和涡旋搅拌时间。在选定的参数下（萃取溶剂：氯仿，130 μL；分散溶剂：异丙醇，400 μL；不加盐且无涡旋搅拌时间），该方法得到了完全验证，所有参数均符合文献建议。使用少于550 μL的有机溶剂对患者血浆样本中的左乙拉西坦进行了定量。
