Bioanalysis of Raltegravir, an Integrase Inhibitor in Human Plasma by Novel SPE-ESI-LC-MS/MS method and its pharmacokinetic application

This paper describes a simple, rapid and sensitive bioanalytical method based on liquid chromatography / tandem mass spectrometry (LC–MS/MS) for the determination of integrase inhibitor raltegravir in human plasma samples. Carbamazepine was used as an internal standard (IS). Analyte and the internal standard were extracted from 200 µL of human plasma via solid phase extraction. The chromatographic separation was achieved on a C18 column by using a mixture of acetonitrile and 0.1% formic acid (90:10, v/v) as the mobile phase at a flow rate of 0.8 mL/min. The calibration curve obtained was linear (r2 ³ 0.99) over the concentration range of 20.1–4007 ng/mL. Method validation was performed as per FDA guidelines and the results met the acceptance criteria. A run time of 2.0 min for each sample made it possible to analyze more number of samples in short time, thus increasing the productivity. The proposed method was found to be applicable to pharmacokinetic studies in humans.