Development and validation of a chromatographic ultraviolet method for the simultaneous quantification of dolutegravir and rilpivirine in human plasma

Background: We have developed and validated a high-performance liquid chromatographic method for the simultaneous quantification, in human plasma, of dolutegravir, a new human immunodeficiency virus (HIV) integrase inhibitor, and rilpivirine, a novel HIV nonnucleoside reverse transcriptase inhibitor. Methods: An internal standard (quinoxaline) was added to plasma aliquots (500 μL), and a simple solid-phase extraction procedure was applied. Chromatographic separation of the drugs and internal standard was achieved with a gradient of acetonitrile and acetate buffer, and with an analytical run time of 25 minutes using an XBridge C18 column. The column eluate was monitored at 260 nm for dolutegravir and the internal standard and at 305 nm for rilpivirine. Results: The method was linear in the range of 20–8000 and 20–2000 ng/mL for dolutegravir and rilpivirine, respectively (mean r2 ≥ 0.993 on 10 replicates for both analytes). Mean intraday and interday precision and inaccuracy were <15% for both compounds. The mean recovery was 73% and 80% for dolutegravir and rilpivirine, respectively. Conclusions: The high-performance liquid chromatography–ultraviolet method we developed showed a good analytical performance required for therapeutic drug monitoring of antiretrovirals, leading to potential improvements in HIV-infected patient care and laboratory management.