Bioanalytical LC‐MS/MS method validation for plasma determination of topiramate in healthy Indian volunteers

Abstract

A LC-MS/MS method for plasma topiramate analysis is delineated involving least number of healthy volunteers. Topiramate and amlodipine internal standard (IS) were extracted by simple centrifuge-coupled solid-phase extraction and reverse-phase chromatographic separation was performed on an Ascentis C(18) column. Turbo-spray negative-ion mode multiple-reaction monitoring was selected for mass pair detection at m/z 338.3 --> 78.0 and m/z 407.3 --> 295.5 for analyte and IS respectively. The method showed a dynamic linearity range from 10.4 to 2045.0 ng/mL, lower limit of quantitation achieved at 10.4 ng/mL and finally a mass spectrometric total run time of within 2.5 min for human sample analysis. Bioequivalence was assessed successfully using this fully validated method on 16 fasted Indian male subjects with 25 mg topiramate tablet administration. An appropriate study design describes plasma samples collection up to 216 h post dose in two periods, separated by a 28 day washout period. The challenge of half-life matching for test and reference drug was achieved with 73.43 +/- 9.68 and 73.06 +/- 14.03 h, respectively, and intra-subject coefficient of variation achieved within 11% for AUCs and C(max) evaluated by non-compartmental pharmacokinetic analysis. The results of LCMS topiramate complete method validation supported by pharmacokinetic study have not been published before, and are presented and discussed for the first time in this article.

Simple and sensitive high performance liquid chromatography method with fluorescence detection for therapeutic drug monitoring of topiramate

“…For various reasons, including insufficient analytical sensitivity 12,23,24,26,28,29,31,35 and linearity, 24,25,[32][33][34]36 previously reported liquid chromatography techniques coupled with various detection systems can not accurately determine full therapeutic range of TPM concentrations. These methods either lack adequate sensitivity, and consequently cannot be applied in pharmacokinetic studies, or the method range is to narrow and therefore they are not practical for routine TDM.…”

“…It needs to be emphasized that sensitivity of the present HPLC-FLD method is comparable to the sensitivity of the more sophisticated LC-MS methods, 30,[32][33][34]36 which makes it appropriate also for pharmacokinetic profiling and bioequivalence assessments of low-dose TPM formulations in healthy volunteers.…”

“…15 Various analytical methods have been reported for measurement of TPM in biological fluids, including immunoassays, 16,17 gas chromatography (GC) coupled to flame ionization detection (FID) 18 or nitrogen phosphorous detection (NPD), [19][20][21][22] high performance liquid chromatography with UV (HPLC-UV) 23 or fluorescence detection (HPLC-FLD), [24][25][26] capillary electrophoresis with UV detection, 27 liquid chromatography coupled to mass spectrometry (LC-MS), 28,29 and more recently, liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). 12,[30][31][32][33][34][35][36] The analysis of TPM in biological fluids is complicated, because like most other carbohydrates and their derivatives, TPM does not contain any chromophores that absorb above 190 nm. Consequently, TPM has extremely low UV-visible absorbance and no spontaneous fluorescence, and cannot be directly analyzed by conventional HPLC with UV or fluorescence detection.…”

Therapeutic drug monitoring and LC–MS/MS

“…Topiramate can also be ionised in positive ion mode, but sensitivity is increased if negative ionisation is used [77][78][79][80][81][82]. A C18 analytical column is commonly used for quantification of these drugs.…”

Topiramate: a review of analytical approaches for biological matrices

“…Thus, HPLC-MS/MS provides much more selectivity compared with other systems of detection. Kuchekar et al (2010), Goswami et al (2009) andPopov et al (2013a) proposed different methods to determine topiramate in human plasma, achieving a low LOQ of 10 ng/mL. Topiramate analysis by HPLC-MS/ MS can be set in both negative and positive modes; however the system using the ESI-negative mode is the most common (Table 2).…”