High-performance liquid chromatographic method for the determination of HIV-1 non-nucleoside reverse transcriptase inhibitor efavirenz in plasma of patients during highly active antiretroviral therapy

A new high-performance liquid chromatographic method for the determination of efavirenz in human plasma is described. Quantitative recovery following liquid–liquid extraction with diethylether from 200 μl of human plasma was achieved. Subsequently, the assay was performed with 67 mM potassium dihydrogen phosphate–acetonitrile as a mobile phase, a XTerraRP 18 column protected with a Phenomenex C18 column and UV detection at 246 nm. Linear standard curves were obtained for concentrations ranging from 25 to 15 000 ng/ml. The calculated intra- and inter-day coefficients of variation were below 10%.