Simple and rapid liquid chromatography method for determination of efavirenz in plasma

A simple and rapid high performance liquid chromatographic method for determination of efavirenz in human plasma was developed. The method involved extraction of sample with ethyl acetate and analysis using a reversed-phase C18 column (150 mm) with UV detection. The assay was linear from 0.0625 to 10.0 μg/ml. The method was specific for efavirenz estimation and the drug was stable in plasma up to one month at −20 °C. The average recovery of efavirenz from plasma was 101%. Due to its simplicity, the assay can be used for pharmacokinetic studies and therapeutic drug monitoring of efavirenz.