Diazepam determination

R Dixon, T Crews. Diazepam Determination in micro samples of blood, plasma, and saliva by radioimmunoassay. J Anal Toxicol 2 210, 1978. 

MLcromethod of Blood Diazepam Determination by Gas-Liquid Chromatography. Application in Neonatal Pharmacology... 

The comparison of predicting capabilities of two kinds of hydrophobicity evaluations is of interest. For these purpose partition coefficients P and P for a number of benzodiazepines gidazepam (I), medazepam (II), nitrazepam (III), oxazepam (IV), lorazepam (V) and diazepam (VI) were determined. 

Benzodiazepines. Figure 3 Dissection of benzodiazepine pharmacology. The functional roles of GABAa receptor subtypes, mediating particular actions of diazepam, are indicated. A sign indicates that the respective response is mediated by the respective receptor subtype, a sign indicates that the respective response is apparently not mediated by the respective receptor subtype. ND = not determined. 

Stuer et al. [46] evaluated the presence of the 25 most used pharmaceuticals in the primary health sector in Denmark (e.g., paracetamol, acetyl salicylic acid, diazepam, and ibuprofen). They compared PECs with experimental determinations and they conclude that measured concentrations were in general within a factor of 2-5 of PECs. Carballa et al. [45] also determined PECs for pharmaceuticals (17), musk fragrances (2) and hormones (2) in sewage sludge matrix. For that purpose they used three different approaches (1) extrapolation of the per capita use in Europe to the number of Spanish inhabitants for musk fragrances (2) annual prescription items multiplied by the average daily dose for pharmaceuticals and (3) excretion rates of different groups of population for hormones. They indicated that these PECs fitted with the measured values for half of them (carbamazepine, diazepam, ibuprofen, naproxen, diclofenac, sulfamethoxazole, roxithromycin, erythromycin, and 17a-ethiny I e strad iol). 

In order to determine more precisely the fate of pharmaceuticals during sludge treatment, different experiments have been conducted in controlled conditions. In continuous anaerobic reactors treating sludge spiked with pharmaceuticals, Carballa et al. [114] observed removals higher than 80% for naproxen, sulfamethoxazole, and roxithromycin, while 40% and 23% of ibuprofen and iopromide, respectively, were eliminated at both mesophilic (37°C) and thermophilic (55°C) temperatures. For diclofenac and diazepam, elimination of about 60% was observed in mesophilic conditions while in thermophilic conditions, 38% and 73% of these two compounds, respectively, were eliminated. In these experiments, the sludge retention time (15 or 30 days) did not seem to influence pharmaceutical removal... 

Iwase H, Gondo K, Koike T, Ono I. 1994. Novel precolumn deproteinization method using a hydroxyapatite cartridge for the determination of theophylline and diazepam in human plasma by high-performance liquid chromatography with ultraviolet detection. J Chromatogr B Biomed Appl 655(1) 73-81. Erratum in J Chromatogr B Biomed Appl 660(2) 422. 

Eurlanetto, S., Orlandini, S., Massolini, G., Faucci, M. T., La Porta, E., and Pinzauti, S. (2001). Optimisation and validation of a capillary electrophoresis method for the simultaneous determination of diazepam and otilonium bromide. Analyst 126(10), 1700-1706. 

Diazepam, oxazepam, and N-desmethyldiazepam have been determined under isocratic conditions (342) a somewhat more sensitive assay for diazepam and N-methyldiazepam has been reported (545). The closely related compounds, chlordiazepoxide and its N-demethyl metabolite, have also been determined (344). Analysis of the antidepressant amitriptyline, its metabolites and related drugs have been carried out using a four-component solvent (345, 346) and also aqueous acetonitrile (547). 

AA Omran, K Kitamura, S Takegami, A-AY El-Sayed, M Abdel-Mottaleb. Determination of partition coefficients of diazepam and flurazepam between phosphatidylcholine bilayer vesicles and water by second derivative spectro-photometric method. J Pharm Biomed Anal 25 319-324, 2001. 

Eight BDZs among the most frequently encountered in forensic toxicology (clonazepam, desal-kylflurazepam, diazepam, flunitrazepam, lorazepam, midazolam, nordiazepam and oxazepam) were determined in whole blood after solvent extraction with butyl chloride and fast isocratic separation using a C18 (100 x 4.6 mm x 5 (tm) column [61]. The mobile phase was composed of phosphate buffer (35mM, pH 2.1) and acetonitrile (70 30, v/v) and the flow rate was 2mL/min. Within less than 4 min of analysis time, the analytes could be successfully determined starting from therapeutic concentrations. Using HPLC coupled with APCI-MS-MS, Rivera et al. [62] set up a method for the detection of 18 BDZ and metabolites after butyl chloride extraction at alkaline pH in 0.5mL... 

Polarographic methods have been extremely useful for the determination of the urinary excretion of the 1,4-benzodiazepines. An assay that employs selective solvent extraction and acid hydrolysis of diazepam and its major metabolites, iV-desmethyldiazepam and oxazepam, to their respective benzophe-nones has been employed to measure the urinary excretion of diazepam [183]. A pulse polarographic assay has been reported that will measure the urinary excretion of bromazepam following a single 12-mg dose [184]. The assay employs selective extraction of bromazepam and the 2-amino-5-bromobenzoyl-pyridine metabolite from the deconjugated metabolites, 3-hydroxybromazepam and 2-amino-3-hydroxy-5-bromobenzoylpyridine, into separate diethyl ether fractions. The residues of the respective extracts are dissolved in phosphate buffer (pH 5.4) and analyzed by pulse polarography, which yields two distinct... 

The determination of diazepam in plasma with detection limits of 0.03-0.2 fjLg/mh by cathode ray [189] and pulse polarography [174,190] has been described. The first reported pulse assay [174] differs from the other polarographic assays [189,190] in that a more polar solvent is employed to ensure quantitative extraction, followed by TLC separation and determination of diazepam and its major blood metabolite, N-desmethyldiazepam, to ensure specificity. 

Sultana et al. [88] developed a reversed-phase HPLC method for the simultaneous determination of omeprazole in Risek capsules. Omeprazole and the internal standard, diazepam, were separated by Shim-pack CLC-ODS (0.4 x 25 cm, 5 m) column. The mobile phase was methanol-water (80 20), pumped isocratically at ambient temperature. Analysis was run at a flow-rate of 1 ml/min at a detection wavelength of 302 nm. The method was specific and sensitive with a detection limit of 3.5 ng/ml at a signal-to-noise ratio of 4 1. The limit of quantification was set at 6.25 ng/ml. The calibration curve was linear over a concentration range of 6.25—1280 ng/ml. Precision and accuracy, demonstrated by within-day, between-day assay, and interoperator assays were lower than 10%. 

Lipid solubility plays a major role in determining the rate at which a particular sedative-hypnotic enters the central nervous system. For example, diazepam and triazolam are more lipid-soluble than chlordiazepoxide and lorazepam thus, the central nervous system actions of the former drugs are... 

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