A rapid high-performance liquid chromatographic method for the measurement of midazolam plasma concentrations during long-term infusion in ICU patients.
Ther Drug Monit
; 19(3): 352-7, 1997 Jun.
Article
en En
| MEDLINE
| ID: mdl-9200778
ABSTRACT
A new high-performance liquid chromatographic method was developed for quantification of midazolam in plasma samples from intensive care unit patients on long-term intravenous infusion of this benzodiazepine. Plasma samples (0.5 ml) were mixed with 1 microgram flurazepam (internal standard), alkalinized with 2.5 N NaOH, and extracted with toluene. The organic phase was evaporated to dryness, and the residue was dissolved in the mobile phase (acetonitrile/0.05 M phosphate buffer pH 4.5) and injected into the analytical column (C18 Nova-Pak 3.9 x 150 mm, 4 microns, maintained at room temperature; mobile phase flow rate 1.2 ml/minute). The eluate was monitored at 207 nm, which reduced the risk of interferences from concurrent medications. Retention times of flurazepam, 1'-hydroxymidazolam (an active metabolite) and midazolam were approximately 4.5, 6.1 and 13.5 minutes, respectively. The assay was linear over the range 100 to 3000 ng/ml. The coefficients of variation of the within-day and between-day assay for the 100 to 3000 ng/ml range were < 5% and < 7%, respectively. The developed method is fast, reproducible, and well suited to monitor steady state midazolam plasma concentrations in clinical samples.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Midazolam
/
Cromatografía Líquida de Alta Presión
/
Anestésicos Intravenosos
Límite:
Humans
Idioma:
En
Revista:
Ther Drug Monit
Año:
1997
Tipo del documento:
Article
País de afiliación:
Bélgica