Quantitative determination of efavirenz (DMP 266), a novel non-nucleoside reverse transcriptase inhibitor, in human plasma using isocratic reversed-phase high-performance liquid chromatography with ultraviolet detection
Ai. Veldkamp et al., Quantitative determination of efavirenz (DMP 266), a novel non-nucleoside reverse transcriptase inhibitor, in human plasma using isocratic reversed-phase high-performance liquid chromatography with ultraviolet detection, J CHROMAT B, 734(1), 1999, pp. 55-61
Efavirenz is a novel non-nucleoside reverse transcriptase inhibitor for the
treatment of HIV-1-infected individuals. A simple and rapid high-performan
ce liquid chromatographic method for the quantification of efavirenz in hum
an plasma suitable for therapeutic drug monitoring in plasma is described.
Sample pretreatment consists of protein precipitation with acetonitrile and
subsequent evaporation of the extract to concentrate the analyte. The drug
is separated from endogenous compounds by isocratic reversed-phase high-pe
rformance liquid chromatography with ultraviolet detection at 246 nm. The m
ethod has been validated over the range of 10 to 10 000 ng/ml using a volum
e of 250 mu l of plasma. The assay is linear over this concentration range
as indicated by the F-test for lack of fit. Within- and between-day precisi
ons are less than 4.3% for all quality control samples. The lower limit of
quantitation is 10 ng/ml and the recovery of efavirenz from human plasma is
106.4% (+/-1.8%). Frequently co-administered drugs did not interfere with
the described methodology. Efavirenz is stable under Various relevant stora
ge conditions, for example when stored for 24 h at room temperature. This v
alidated assay is suited for use in pharmacokinetic studies with efavirenz
and can readily be implemented in the setting of a hospital laboratory for
the monitoring of efavirenz concentrations. (C) 1999 Elsevier Science B.V.
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