Abstract
In this study, a highly sensitive method to simultaneously quantify the integrase strand transfer inhibitors （INSTIs） raltegravir, dolutegravir, elvitegravir, and bictegravir, which are recommended drugs in the HIV treatment guidelines, was established using liquid chromatography–tandem mass spectrometry （LC-MS/MS）. Raltegravir-d3 was used as the internal standard substance. The plasma samples were deproteinized with methanol and analyzed by LC-MS/MS. Chromatographic separation was performed using the gradient method with a mobile phase A （20mmol/l ammonium formate - water） and mobile phase B （20mmol/l ammonium formate - methanol）. In addition, an InertSustain C18 column （3µm, 100×2.1mm）, a flow rate of 0.45ml/min, and a measurement time of 10 minutes were used. The calibration curve showed linearity （r2＞0.9904） within the range of 0.5-1,250ng/ml, and the limit of quantification was 0.5ng/ml for all drugs. The mean intra- and inter-day accuracy was 99.6％±7.2％ and 101.0％±5.0％, respectively, and the coefficient of variation （CV） was ≤18.5％ and ≤10.3％, respectively. This method enables the highly sensitive simultaneous analysis of INSTIs and is useful for confirming the efficacy and safety of drugs in clinical practice.
