Development and validation of an HPLC-UV method for quantification of elvitegravir and others new antiretrovirals, dolutegravir and rilpivirine, in the plasma of HIV-positive patients

Therapeutic drug monitoring may be crucial in selected clinical conditions for the management of HIV infection. In the last years, new antiretrovirals have been introduced and in particular elvitegravir (EVG) is now recommended for first-line and in simplification treatment as well as dolutegravir (DTG) and rilpivirine (RPV). The aim of this study was to develop and validate a High Performance Liquid Chromatography-Ultra Violet (HPLC-UV) method for determining EVG and others newest antiretrovirals DTG and RPV in human plasma. A solid-phase extraction was applied to a 600 μL plasma sample. Chromatographic separation of the three drugs and internal standard were achieved with a gradient of acetonitrile and phosphate buffer on a C-18 reverse-phase analytical column with a 20-minute analytical run time. EVG, DTG were detected at 265nm and RPV at 290nm. Mean intra-day and inter-day precisions were < 10%; the mean accuracy was < 15%. Extraction recovery ranged between 105% and 82% for the drugs analyzed. Calibration curves were optimized according to the expected ranges of drug concentrations in patients; the coefficient of determination was higher than 0.997 for all drugs. This method allows for monitoring EVG, DTG and RPV in the plasma of HIV-positive patients using HPLC-UV.