Liquid-chromatographic assay of diazepam and its major metabolites in serum, and application to pharmacokinetic study of high doses of diazepam in schizophrenics.

Abstract

In this rapid, sensitive method for simultaneously determining diazepam and its biologically active metabolites--nordiazepam, oxazepam, and temazepam--in serum, 250 to 1000 microL of serum is extracted with ether and the extracted compounds are quantified by "high-performance" liquid chromatography on a Shimpack FLC-C8 microparticulate column. Absorbance of the effluent is monitored at 254 nm. The limit of detection in serum is about 10 micrograms/L for each drug. Analytical recovery of each drug added to the serum varied from 91 to 102% for oxazepam and temazepam, from 82 to 99% for nordiazepam and diazepam. Within-day and between-day CVs ranged from 2 to 5% for oxazepam and temazepam, and from 2 to 7% for nordiazepam and diazepam. We also report results on using this assay in a pharmacokinetic study of high doses of diazepam used to treat chronic schizophrenic patients.

Hybrid sol gel coating: A solution to prevent interactions between plasticized poly(vinyl chloride) and injectable drugs?

“…Diazepam analysis was performed at 254 nm with a mobile phase consisting of a mixture methanol‐water (65/35 v/v) pumped at a flow rate of 1.5 mL/min. Two hundred and fifty‐four nanometers is the wavelength recommended by the European Pharmacopea and the one used by Kambia et al and Tada et al The injection volume was of 20 μL. Diazepam calibration curve was constructed at a concentration range of 10–200 μg/mL.…”

Potentiometric Determination of Clonazepam Using Carbon Paste Electrode Based on Molecular Imprinted Polymer (MIP) in Solution and in a Biological Fluid Model

“…Hence, it is necessary to develop a specific and rapid method for the determination of clonazepam in biological fluids. Several methods were already published involving spectrophotometry [14][15][16][17][18], gas chromatography [19][20][21][22][23] with or without derivatization and liquid chromatography (LC) [24][25][26][27][28][29], spectrofluorimetry, differential pulse polarography and non-aqueous titration [30][31][32][33][34][35][36][37][38][39][40], HPLC with UV spectrophotometric and fluorescence detection systems [41][42][43][44][45][46]. Most of the LC methods suffer from either extensive sample preparation involving two extractions, time-consuming for sample preparation, long-time analysis or expensive equipment, and therefore they are not suitable for routine works.…”