Separation and HPLC analysis of 15 benzodiazepines in human plasma

Abstract

Benzodiazepines (BZDs) are often prescribed to schizophrenic or depressed patients, as a part of polypharmacy regimens. An HPLC method has been developed for the simultaneous determination of 15 BZDs in human plasma. Separation was obtained by using a C8 RP column and a mobile phase composed of 65% aqueous phosphate buffer at pH 3.0 and 35% ACN. The UV detector was set at 220 nm and clomipramine was used as the internal standard. A careful pretreatment procedure of plasma samples was developed, using SPE with C1 cartridges, which gives high extraction yields (> 97%). The LOQs were always lower than 7.6 ng/mL and the LODs always lower than 2.6 ng/mL for all analytes. The method was successfully applied to plasma samples from depressed and schizophrenic patients undergoing polypharmacy with one or more BZDs. Precision data, as well as accuracy results, were satisfactory and no interference from other drugs was found. Hence, the method seems to be suitable for the therapeutic drug monitoring (TDM) of patients undergoing therapy with one or more BZDs.

Separation and Quantification of 1,4-benzodiazepines: HPLC versus CZE

“…2,7,14,15 The first column tested was Zorbax SB-C8 packed with an endcapped octyl-silica gel stationary phase. The most suitable mobile phase composition found in isocratic elution mode was ACN/deionised water with acetic acid, pH 3.0, 30/70 (v/v).…”

“…3,4 Many studies on these drugs can be found in the literature. [5][6][7][8] Diverse analytical methods for determination of benzodiazepines in various matrices have been published, 9,10 e.g. potentiometry, 11 immunoassays, 12 spectrophotometry 13 and also separation techniques that represent a clear majority of the reported methods because they allow determination of individual compounds in often rather complicated mixtures.…”

“…potentiometry, 11 immunoassays, 12 spectrophotometry 13 and also separation techniques that represent a clear majority of the reported methods because they allow determination of individual compounds in often rather complicated mixtures. While HPLC remains the most common technique for the analysis of benzodiazepines, 7,9,14,15 mainly in reversed phase (RP) mode, several capillary zone electrophoresis (CZE) methods have recently been developed. 2,16,17 CZE represents an interesting alternative to HPLC for determination of pharmaceuticals, in general, 18,19 mainly because of its higher efficiency in comparison with HPLC.…”

Experimental design for optimization of microwave-assisted extraction of benzodiazepines in human plasma

“…Liquid chromatography has become an important tool for routine determination of BZD owing to its specificity, rapidity and sensitivity [4][5][6][7][8]. Although high-performance liquid chromatography (HPLC) with mass spectrometry detection [5][6][7] is highly selective, the cost of the instrumentation makes it less suitable for clinical or toxicology laboratories.…”

“…Although high-performance liquid chromatography (HPLC) with mass spectrometry detection [5][6][7] is highly selective, the cost of the instrumentation makes it less suitable for clinical or toxicology laboratories. In contrast, HPLC-UV detection or diode array detection (DAD) instrumentation is widely available in most analytical laboratories [8][9][10][11][12].…”