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Electron‐capture gas chromatographic determination of loprazolam in plasma and a pharmacokinetic application
Author(s) -
Levasseur F. A.,
Caillé G.,
Elie R.,
Vézina M.,
Larivière L.
Publication year - 1985
Publication title -
biopharmaceutics and drug disposition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.419
H-Index - 58
eISSN - 1099-081X
pISSN - 0142-2782
DOI - 10.1002/bdd.2510060404
Subject(s) - pharmacokinetics , chemistry , chromatography , capsule , coefficient of variation , plasma , pharmacology , medicine , botany , biology , physics , quantum mechanics
Abstract A sensitive and specific gas chromatographic method, using an electron capture detector, for the measurement of plasma concentrations of loprazolam (HR‐158) is described. Retention times of the hydrolysis product of loprazolam (2‐amino‐2′‐chloro‐5‐nitrobenzophenone) and of the internal standard (2‐amino‐2′‐ fluorobenzophenone) were, respectively, 9 and 7 minutes. The sensitivity of the assay was 1.0 ng ml −1 of plasma, and for drug concentrations ranging from 1.0 to 15 ng ml −1 the mean recovery from plasma was 94.4 per cent and the mean coefficient of variation 9.8 per cent. This method was used to determine some pharmacokinetic parameters of loprazolam after administration of 2 × 1 mg capsule doses to nine healthy. fasted volunteers. The mean t 1/2 was 6.4 h. mean AUC x 65.42 ng.h ml −1 , and the mean clearance 0.51 l min −1 .