Determination of Clobazam and Its Major Metabolite N-desmethylclobazam in Human Plasma with High-Performance Liquid Chromatography

Abstract

Clobazam (CLB) is a benzodiazepine that is used in many types of epilepsy. Although therapeutic drug monitoring (TDM) of CLB is not routine, there is evidence that TDM may be of value in conditions where pharmacokinetic alterations are suspected. Therefore, determination of both CLB and its active metabolite concentrations is essential for TDM. Herein, we present a simple and practical method for determination of CLB and N-desmethylclobazam (NDMCLB) in human plasma by high-performance liquid chromatography (HPLC). The drugs were extracted by hexane:dichloromethane (1:1, v/v) from 0.3 mL plasma. The separation was carried out with a C18 reverse phase column using a mobile phase of water:acetonitrile (57:43, v/v) pumped at 0.8 mL/min. The analytes were detected at 228 nm. The method was linear over the concentration range 20–500 ng/mL for CLB and 200–3000 ng/mL for NDMCLB. The intra-day coefficient of variation (CV) was <10% for CLB and <6% for NDMCLB, while the inter-day CV for CLB was <16%. The metabolite inter-day CV was <6%. The accuracy of intra- and inter-day assessments determined for CLB and NDMCLB was within ±10%. This paper describes a rapid, reliable, and simple method for measuring CLB and its metabolite NDMCLB in human plasma. This UV-HPLC procedure offers acceptable precision and accuracy to quantify CLB and its metabolite in human plasma.

Cenobamate significantly improves seizure control in intellectually disabled patients with drug-resistant epilepsy and allows drug load reduction

“…As we gained more experience in administering CNB, the interaction with clobazam emerged as a notable issue. Clobazam’s structure, confers preferential binding to the GABA A alpha-2 receptor ( 27 ). N-CLB has a considerably longer half-life (59–74 h) than clobazam (36–42 h) and contributes to the drug’s spectrum of pharmacological effects.…”

A Simple and Reliable Liquid Chromatographic Method for Simultaneous Determination of Five Benzodiazepine Drugs in Human Plasma

“…Nordiazepam, which is classified as diazepam metabolites from the effect of liver enzymatic behavior, as mentioned in [32], was separated in the current method with a good resolution of 1.9. Furthermore, a surfactant was used as an additive in the mobile phase without requiring sample treatment [9,35,36]; however, the current method has also used a simple and reliable liquid-liquid methodology for the sample treatment [15]. A repeated injection of concentration of 50 ng mL −1 , including intra-inter day assessments for standard methanolic and plasma matrices, was used to measure the system's suitability.…”

“…The treatment of real human plasma matrices was carried out by liquid-liquid extraction (methanol), which is still used as a simple and reliable sample treatment technique [15]. Donors were selected on condition with healthy volunteers aged between 30 and 45 years (n = 5).…”

“…nique [15]. Donors were selected on condition with healthy volunteers aged between 30 and 45 years (n = 5).…”

Spectrophotometric Estimation of Clonazepam as Pure Form and in its Pharmaceutical Formulation (Tablet) Using Alizarin Red S

“…Various chromatographic methods were also used to estimate CLZM whether in pharmaceutical preparations or biological body fluids such as HPLC (Gadge et al, 2020;Spell and Stewart, 1998;Isse and Mahmoud, 2021;Naidu et al, 2018), UPLC/MS-MS (Xu et al , 2019), GC-MS (Santhosh et al ., 2019;Fang et al . , 2020) as well as to other analytical methods such as voltammetry (Lotfi and Veisi, 2019;Sachdeva et al ., 2021;Honeychurch et al .…”