Simultaneous determination and pharmacokinetics of midazolam and its hydroxymetabolites in plasma and urine of man and dog by means of high-performance liquid chromatography.

A HPLC (high performance liquid chromatography) method for the determination of 8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a] [1,4]benzodiazepine (midazolam, Ro 21-3981, Dormicum) and its hydroxy metabolites has been developed. The half-life of elimination of midazolam and the glucuronides of the metabolites 1-hydroxymethyl-midazolam, 4-hydroxy-midazolam and 1-hydroxymethyl-4-hydroxy-midazolam are identical, 53 min in dogs and 90 min in man.