Determination of Lamotrigine Simultaneously with Carbamazepine, Carbamazepine Epoxide, Phenytoin, Phenobarbital, and Primidone in Human Plasma by SPME-GC-TSD

Abstract

A simple and rapid analytical method is presented for the determination of lamotrigine simultaneously with primidone, carbamazepine, carbamazepine epoxide, phenobarbital, and phenytoin in human plasma using solid-phase microextraction (SPME) and gas chromatography with thermionic specific detection. The best conditions for the SPME procedure is established as following: direct extraction on a 65-microm Carbowax-divinylbenzene fiber; 1.0 mL of a sample plasma matrix modified with 15% NaCl and 3 mL of a potassium phosphate buffer (pH 7.0); extraction temperature at 30 degrees C; and stirring at a rate of 2500 rpm for 15 min. The method shows good linearity between 0.05 and 40.0 microg/mL with regression coefficients ranging between 0.9965 and 0.9995 and a coefficient of variation of the points of the calibration curve lower than 10%. The lowest limit of quantitation for the plasma-investigated drugs varies from 0.05 to 0.20 microg/mL, according to the drug. The proposed method is sensitive enough to work into subtherapeutic and therapeutic concentrations, being that it is applied in pharmacokinetic studies and patient routine therapeutic drug monitoring.

Construction of different types of ion-selective electrodes and validation of direct potentiometric determination of phenytoin sodium

“…There are some indications that phenytoin has other effects, including anxiety control and mood stabilization, although it has never been approved for those purposes by the FDA [1]. sodium Several methods have been reported for the determination of phenytoin sodium using HPLC [2][3][4][5][6][7], LC-MS [8,9], GC [10][11][12], spectrophotometry [13,14], capillary zone electrophoresis [15], polarography [16], potentiometry [17]. This work describes two different implementation of a new and selective type of membrane sensors: plastic membrane and coated wire electrodes for the determination of phenytoin sodium in pure solutions, pharmaceutical preparations and biological fluids.…”

Modern Methods for Analysis of Antiepileptic Drugs in the Biological Fluids for Pharmacokinetics, Bioequivalence and Therapeutic Drug Monitoring

“…The primary methods for the analysis of serum CBZ are commercial reagent-based techniques like as FPIA and EMIT [22,23]. However, there are also many GC and HPLC techniques with UV or mass spectrometry (MS) detection available and these have the advantage of simultaneously measuring other AEDs and the active metabolite CBZ-10,11-epoxide [15,16,[24][25][26][27][28]. But most of these assays employ UV detection, thereby increasing the risk of metabolite or matrix interferences.…”

“…The primary methodology for the analysis of PHE in serum are commercial reagent-based techniques such as FPIA, EMIT, and radioimmunoassay (RIA) [71,72]. Because of its widespread use, there are also many GC [25,[73][74][75][76] and HPLC techniques with various sample preparation procedures or detection methods such as UV or MS [30,[77][78][79][80] available, which can measure simultaneously other AEDs in biological fluids. MLC procedures involving direct injection of biological fluids have been reported for the determination of PHE levels [81].…”

“…Presumably this is because of the accumulation of PHT metabolites; however, much of the cross-reactivity has been minimized or eliminated in more recent assay development [86]. However, there are also many GC with various detection [25,89] and HPLC methods have been reported [10,11,80,90]. Treatments for refractory epilepsy with a second drug or a combination of drugs indicate the need for simultaneous HPLC analysis for other AEDs [15,16,24,76,91,92].…”

Padronização e validação do método extração sortiva em barra de agitação e cromatografia líquida de alta eficiência (SBSE/HPLC) para a determinação de antidepressivos em amostras de plasma

“…Figura 6 -(a) Processo de extração SPME, (b) Processo de dessorção térmica SPME-GC, (c): Processo de dessorção SPME-HPLC b do inglês: solid-phase microextraction-high performance liquid chromatography A técnica SPME-GC, inicialmente desenvolvida para a análise de poluentes em amostras ambientais, [39][40][41][42] tem sido empregada com êxito na extração de fármacos voláteis e semivoláteis em análises de amostras biológicas, 43,44 principalmente quando analisados no modo "headspace", 31 no qual não ocorre a interação das proteínas do plasma com a fibra. Já os fármacos menos voláteis ou termicamente instáveis têm sido analisados após processos de derivatização/SPME-GC ou empregando a técnica SPME-HPLC.…”