SIMULTANEOUS DETERMINATION OF MIDAZOLAM AND FLUMAZENIL CONCENTRATIONSIN HUMAN PLASMA BY GAS-CHROMATOGRAPHY

A gas chromatographic method for the simultaneous determination of mid azolam and flumazenil concentrations in human plasma has been develope d, using clinazolam as the internal standard. A mixture of chloroform and ethyl acetate (80:20) was used to extract the two compounds. A 2-m u l volume of the reconstituted sample was injected using a 1:20 split injection mode. Intra-day coefficients of variation ranged from 2 to 6.9%. The assay was linear over the range 3-1000 ng/ml. This assay was subsequently used to analyze samples from a human pharmacokinetic stu dy.