A chiral HPLC‐UV method for the quantification of dibenz[b,f]azepine‐5‐carboxamide derivatives in mouse plasma and brain tissue: Eslicarbazepine acetate, carbamazepine and main metabolites

Abstract

For the first time, a selective and sensitive chiral HPLC-UV method was developed and fully validated for the simultaneous quantification of eslicarbazepine acetate (ESL), carbamazepine (CBZ), S-licarbazepine (S-Lic), R-licarbazepine (R-Lic), oxcarbazepine (OXC) and carbamazepine-10,11-epoxide (CBZ-E), in mouse plasma and brain homogenate supernatant. After the addition of chloramphenicol as the internal standard, samples were processed using an SPE procedure. The chiral chromatographic analysis was carried out on a LiChroCART 250-4 ChiraDex column, employing a mobile phase of water and methanol (88:12, v/v) pumped at 0.9 mL/min and the UV detector set at 235 nm. The assay was linear (r(2) ≥0.995) for ESL, CBZ, OXC, S-Lic, R-Lic and CBZ-E in the range of, respectively, 0.2-4, 0.4-30, 0.1-60, 0.2-60, 0.2-60 and 0.2-30 μg/mL, in plasma, and of 0.06-1.5 μg/mL for ESL, 0.12-15 μg/mL for CBZ and CBZ-E and 0.06-15 μg/mL for OXC and both licarbazepine (Lic) enantiomers in brain homogenate supernatant. The overall precision was within 8.71% and accuracy ranged from -7.55 to 8.97%. The recoveries of all the compounds were over 92.1%. Afterwards, the application of the method was demonstrated using real plasma and brain samples obtained from mice administered simultaneously with ESL and CBZ.

HPLC–DAD Method for the Quantification of Carbamazepine, Oxcarbazepine and their Active Metabolites in HepaRG Cell Culture Samples

“…As previously mentioned, besides the availability of more than 20 AEDs [1], the truth is that the monotherapy with AEDs often fails, requiring polytherapy regimens in an attempt to achieve better seizure control and fewer side effects [29][30][31][32]. Unfortunately, the implementation of polytherapy regimens in the clinical practice frequently originates complex and unpredictable pharmacokinetic and pharmacodynamic interactions, leading to possible clinical consequences in terms of toxicity or even therapeutic inefficacy [30,33].…”

“…The data of the QC samples analysed before (reference samples) were compared with those obtained after being exposed to the experimental conditions for stability assessment (stability samples). As stability criterion (n = 5), a stability/reference samples ratio of 85-115 % was accepted [27,31]. The short-and long-term stability were evaluated, respectively, at room temperature for 4 h and −20 °C for 8 days (n = 5), aiming at simulating sample handling and storage time in the freezer before analysis.…”

Pharmacokinetics, brain distribution and plasma protein binding of carbamazepine and nine derivatives: New set of data for predictive in silico ADME models

“…Samples of mice plasma and brain homogenate were processed by a solid-phase extraction procedure based on methods previously published (Fortuna et al, 2011a(Fortuna et al, , 2011b). An aliquot of plasma sample (300 µL) was added to 700 µL of 0.1 M sodium phosphate buffer (pH 5) and spiked with the adequate internal standard (IS) working solution, while each sample of brain homogenate supernatant (1 mL) was only spiked with IS.…”

“…Chloramphenicol was used as IS. The limits of quantification (LOQ) of CBZ, OXC, ESL, S-Lic, R-Lic and CBZ-E were respectively 0.4, 0.1, 0.2, 0.2, 0.2 and 0.2 µg/mL in plasma and 0.12, 0.06, 0.06, 0.06, 0.06 and 0.12 µg/mL in the supernatant of brain homogenate (Fortuna et al, 2011a). Similar conditions were used for the quantification of BIA 2-059, BIA 2-024, BIA 2-265 and their main metabolites (OXC, S-Lic, R-Lic).…”

Quantification of carbamazepine and its 10,11‐epoxide metabolite in rat plasma by UPLC‐UV and application to pharmacokinetic study

“…Various analytical methods for determining CBZ concentrations in the plasma have been reported, including high‐performance liquid chromatography in conjunction with various detectors, such as UV (Yoshida et al ., ; Ateş et al ., ; Beig et al ., ), electrochemical (Messiha, ) and mass spectroscopy (MS; Kim et al ., ; Zhu et al ., ), and are universally considered accepted methods. Chromatography‐based techniques allow simultaneous detection and quantification of multiple drugs from one sample; however, these methods have high quantification limits and long chromatographic run times, which are not preferable for a large number of samples (McMillin et al ., ; Fortuna et al ., ).…”