We have developed a sensitive, selective and reproducible reversed-phase high-performance liquid chromatography method coupled with electrospray ionization mass spectrometry (HPLC-ESI-MS) for the simultaneous quantification of midazolam (MDZ) and its major metabolite, 1'-hydroxymidazolam (1'-OHM) in a small volume (200 microl) of human plasma. Midazolam, 1'-OHM and 1'-chlordiazepoxide (internal standard) were extracted from alkalinised (pH 9.5) spiked and clinical plasma samples using a single step liquid-liquid extraction with 1-chlorobutane. The chromatographic separation was performed on a reversed-phase HyPURITY Elite C18 (5 microm particle size; 100 mm x 2.1mm i.d.) analytical column using an acidic (pH 2.8) mobile phase (water-acetonitrile; 75:25% (v/v) containing formic acid (0.1%, v/v)) delivered at a flow-rate of 200 microl/min. The mass spectrometer was operated in the positive ion mode at the protonated-molecular ions [M+l]+ of parent drug and metabolite. Calibration curves in spiked plasma were linear (r2 > or = 0.99) from 15 to 600 ng/ml (MDZ) and 5-200 ng/ml (1'-OHM). The limits of detection and quantification were 2 and 5 ng/ml, respectively, for both MDZ and 1'-OHM. The mean relative recoveries at 40 and 600 ng/ml (MDZ) were 79.4+/-3.1% (n = 6) and 84.2+/-4.7% (n = 8), respectively; for 1'-OHM at 30 and 200 ng/ml the values were 89.9+/-7.2% (n = 6) and 86.9+/-5.6% (n = 8), respectively. The intra-assay and inter-assay coefficients of variation (CVs) for MDZ were less than 8%, and for 1'-OHM were less than 13%. There was no interference from other commonly used antimalarials, antipyretic drugs and antibiotics. The method was successfully applied to a pharmacokinetic study of MDZ and 1'-OHM in children with severe malaria and convulsions following administration of MDZ either intravenously (i.v.) or intramuscularly (i.m.).
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http://dx.doi.org/10.1016/j.jchromb.2005.03.015 | DOI Listing |
Front Pharmacol
October 2024
Department of Anesthesiology, Luoyang Central Hospital, Luoyang, China.
Objective: An UPLC-MS/MS method was developed and validated for simultaneous determination of atracurium (ATC), dexmedetomidine (DEX), midazolam (MDZ) and 1-hydroxymidazolam (1-OH-MDZ) and the pharmacokinetics of ATC, DEX, MDZ and 1-OH-MDZ in patients undergoing aortic dissection surgery were investigated.
Methods: The analytes were extracted by acetonitrile precipitation and separated on an Acquity UPLC BEH C18 column (2.1 mm × 50 mm, 1.
Sci Rep
February 2024
Department of Emergency Medicine, Chungnam National University Hospital, Daejeon, 35015, Republic of Korea.
Administration of sedatives for post-resuscitation care can complicate the determination of the optimal timing to avoid inappropriate, pessimistic prognostications. This prospective study aimed to investigate the distribution and elimination kinetics of midazolam (MDZ) and its metabolites, and their association with awakening time. The concentrations of MDZ and its seven metabolites were measured immediately and at 4, 8, 12, and 24 h after the discontinuation of MDZ infusion, using liquid chromatography-tandem mass spectrometry.
View Article and Find Full Text PDFAm J Cardiovasc Drugs
July 2023
Department of Pharmacy, Peking University First Hospital, No.8, Xishiku Street, Xicheng District, Beijing, 100034, People's Republic of China.
Background: We investigated the safety, tolerability, and pharmacokinetics of intravenous recombinant human Neuregulin-1 (rhNRG-1), a DNA recombinant protein for the treatment of chronic heart failure, in healthy Chinese volunteers following single and multiple dose administration.
Methods And Results: To evaluate the safety and tolerance after single-dosing escalation, 28 subjects were divided into six groups (0.2, 0.
Epilepsia Open
June 2023
Department of Molecular Biosciences, University of California, Davis (UC Davis) School of Veterinary Medicine, Davis, California, USA.
The neurosteroid allopregnanolone (ALLO) is under investigation as a treatment for benzodiazepine-refractory status epilepticus (SE). Here, we assess the cardiopulmonary safety of intravenous ALLO by itself and after a clinically recommended dose of midazolam (MDZ) in two healthy adult beagles. Each dog received ALLO (1 mg/kg, IV), and after a washout period of 2 weeks, each dog was dosed with MDZ (0.
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