Identification and quantitation of intact diastereoisomeric benzodiazepine glucuronides in biological samples by high-performance liquid chromatography

The Glucuronidation of R- and S-Lorazepam: Human Liver Microsomal Kinetics, UDP-Glucuronosyltransferase Enzyme Selectivity, and Inhibition by Drugs

“…The analytical conditions for measurement of the R-and S-lorazepam glucuronides were modified from the method of Franzelius and Besserer (1993). HPLC was performed using an Agilent 1100 series instrument (Agilent Technologies, Sydney, NSW, Australia) fitted with a Zorbax Eclipse XBD-C8 analytical column (4.6 Â 150 mm, 5 mm; Agilent Technologies).…”

“…Liquid chromatography-mass spectroemetry analysis of each peak gave m/z values of 497 and 495 in positive and negative ion modes, respectively, which correspond to the molecular mass of lorazepam glucuronide. It is further known that, in general, the R-glucuronides of benzodiazepines elute before the S-glucuronides when separated by reversed-phase HPLC (Ruelius et al, 1979;Franzelius and Besserer, 1993). As indicated in Materials and Methods, substitution of the 3-hydroxy group of lorazepam to form an ester or ether (including lorazepam glucuronide) forms a derivative that is stable to racemization (Lu and Yang, 1990;Baldacci and Thormann, 2006).…”

A fast and sensitive liquid chromatographic–tandem mass spectrometric method for assay of lorazepam and application to pharmacokinetic analysis

“…When HPLC is used for separation of lorazepam with the coexisting species such as its metabolism products, no derivation of the drug is required. Nevertheless, (In these reports [2][3][4][5][6][7][8][9][10][11][12][13][14][15],) either liquid-liquid extraction [2][3][4][6][7][8][9][10][11][12]15] or solid phase extraction [5,13,14] was usually employed to perform matrix removal and analyte pre-concentration prior HPLC separation. The extraction-involved sample pre-treatment procedures could enrich the analyte by several folds even 1-2 orders of magnitude, allowing the HPLC or HPLC/MS to be used for determination of lorazepam in low ppb levels.…”

“…Several methods such as high performance liquid chromatography (HPLC) [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16], gas chromatography (GC) [17][18][19][20][21][22], micellar electrokinetic capillary chromatography (MECC) [23], immunoassay [24][25][26], adsorptive-stripping voltammetry [27], gas chromatography/mass spectrometry (GC/MS) [28][29][30][31][32], tandem mass spectrometry (GC/MS/MS) [33] as well as high performance liquid chromatography/mass spectrometry [34,35] have been reported for the determination of lorazepam in bio-samples. Among them, GC and HPLC coupled with various detectors are most widely used.…”

Forensic Science

“…She immunoassay methods have been compared to GC/NICI-MS for the detection of benzodiazepines in urine (288). Identification and quantitation of intact diastereoisomeric benzodiazepine glucuronides in biological samples has been done by HPLC (289). Chlordiazepoxide and its metabolites in human serum were analyzed by capillary HPLC/FAB-MS (290).…”