Determination of midazolam in human plasma by liquid chromatography with mass-spectrometric detection.
A liquid chromatographic assay with mass-spectrometric detection was developed for the quantitative determination of the cytochrome p450 3A phenotyping probe midazolam in human plasma. Sample pretreatment involved a one-step extraction of 600 microl aliquots with ethyl acetate. Midazolam and the internal standard, lorazepam, were separated on a column (150 mm x 4.6mm, i.d.) packed with 5 microm Zorbax Eclipse XDB-C8 material, using a mobile phase composed of methanol and 10mM aqueous ammonium acetate (60:40, v/v). Column effluents were analyzed using mass-spectrometry with an atmospheric pressure chemical ionization source. Calibration curves were linear in the concentration range of 1.00-200 ng/ml. The accuracy and precision ranged from 92.8 to 112% and 0.056 to 13.4%, respectively, for four different concentrations of quality control samples analyzed in triplicate on eight separate occasions. The developed method was subsequently applied to study the pharmacokinetics of midazolam in a group of 35 human subjects at a single dose of 25 microg/kg.
Lepper
Erin R
ER
Clinical Pharmacology Research Core, Center for Cancer Research, National Cancer Institute, 9000 Rockville Pike, Building 10, Room 5A01, Bethesda, MD 20892, USA.
Hicks
J Kevin
JK
Verweij
Jaap
J
Zhai
Suoping
S
Figg
William D
WD
Sparreboom
Alex
A
D006801:Humans; D006993:Hypnotics and Sedatives / Q000097:blood* / Q000493:pharmacokinetics; D008874:Midazolam / Q000097:blood* / Q000493:pharmacokinetics; D012680:Sensitivity and Specificity
D006993:Hypnotics and Sedatives; D008874:Midazolam