9-Hydroxymethyl-10-carbamoylacridan in human serum is one of the major metabolites of carbamazepine

Determination of antiepileptic drugs in biological material

Current analytical methodologies applied to the determination of antiepileptic drugs in biological material are reviewed. The role of chromatographic techniques is emphasized. Special attention is focused on new chemical entities as well as current trends such as high-speed liquid chromatographic techniques, hyphenated techniques and electrochromatography techniques. A review with 542 references.

Possible relationships between plasma carbamazepine-10,11-epoxide levels and antimanic efficacy and side effects in patients with schizoaffective disorde

We examined the relationships of plasma levels of carbamazepine (CBZ) and its two major metabolites, carbamazepine-10,11-epoxide (CBZ-E) and carbamazepine-10,11-diol (CBZ-D), with antimanic efficacy and side effects in patients with schizoaffective disorder. Positive relationships were found among plasma concentrations of CBZ-E and the degree of clinical improvement and side effects, whereas neither plasma CBZ nor CBZ-D levels were correlated with the degree of clinical improvement or side effects. Copyright 2000 John Wiley & Sons, Ltd.

Carbamazepine: detection of another metabolite in serum, 9 hydroxymethyl-10-carbamoyl acridan

In this article, the authors discuss 9-hydroxymethyl-10-carbamoyl acridan (9-OH-CBZ), another metabolite of carbamazepine (CBZ) found in serum. The retention time of unconjugated 9-OH-CBZ should be known when using a chromatographic method, because it appears in concentrations varying from one eighth to one third of the CBZ-10,11-epoxide (CBZ-E) concentration and may therefore cause analytical interactions. Liquid chromatography/electrospray mass spectrometry ((LC/ES-MS) in a serum extract identified and confirmed 9-OH-CBZ. The amount of 9-OH-CBZ present as conjugate in serum was between 42% and 65%. The correlation factor values (r) between serum concentrations of 9-OH-CBZ and 10,11-dihydro-10,11-trans-dihydroxy-CBZ (trans-CBZ-diol), CBZ-E, and CBZ in 100 serum samples were 0.77, 0.80, and 0.53, respectively. The origin of 9-OH-CBZ is discussed.

Simultaneous determination of carbamazepine and its metabolites in plasma from carbon tetrachloride-intoxicated rats using a new reversed-phase chromatographic column of 2-microns porous microspherical silica gel

A high-performance liquid chromatographic method has been developed for the simultaneous analysis of carbamazepine (CBZ) and its two metabolites, carbamazepine-10,11-epoxide (CBZ-E) and carbamazepine-10,11-dihydroxide (CBZ-diOH), using a recently developed reversed-phase column with 2-microns particles and a 2-microliters microflow cell equipped with a UV detector. The separation was achieved using two different C18 reversed-phase columns (column 1: 100 x 4.6 mm I.D., particle size 2 microns, TSK gel Super-ODS; column 2: 100 x 4.6 mm I.D., particle size 5 microns, Hypersil ODS-C18) for comparison. The mobile phase was composed of methanol-water (30:70, v/v), and the flow-rate was 0.4 ml/min for both columns. The absorbance of the eluent was monitored at 210 nm. Retention times with column 1 were shorter than with column 2. When the three compounds were determined, the sensitivity and limit of quantification were about ten times better with column 1 than with column 2. The relative recovery and linearity with column 1 were approximately the same as those with column 2. These results show that the new ODS column packing with a particle size of 2 microns gives a higher sensitivity and shorter analysis time than the conventional ODS column packing.

Chiral separation of 10,11-dihydro-10, 11-trans-dihydroxycarbamazepine, a metabolite of carbamazepine with two asymmetric carbons, in human serum

Chiral separation of 10, 11-dihydro-10, 11-trans-dihydroxycarbamazepine (CBZ-diol), a metabolite of carbamazepine (CBZ) with two asymmetric carbons, in serum taken from epileptic patients receiving CBZ alone for a long period, was performed by high-performance liquid chromatography using a polysaccharide stationary phase with n-hexane-ethanol (75:25, v/v) as the mobile phase. The enantiomeric ratio (S,S-/R,R-CBZ-diol) was 10.74 +/- 1.13 (mean +/- S.D.), which could demonstrate the presence of the stereospecificity in the hydrolysis of 10, 11-dihydro-10, 11-epoxycarbamazepine (CBZ-epoxide) to CBZ-diol and/or in the conversion of CBZ-diol to some metabolite such as 9-hydroxymethyl-10-carbamoylacridan. This is the first paper to report the determination of each enantiomer and the enantiomeric ratio of CBZ-diol in serum of epileptic patients who received CBZ.