Development and validation of an HPLC method for quantification of dolutegravir in human plasma

Dolutegravir (DTG) has been the first-line drug in many human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) guidelines for the treatment of naïve and experienced HIV-infected individuals, which calls for cost-effective and convenient methods for quantitative detection of DTG in human plasma for pharmacokinetic studies and patient adherence evaluation. Here, an HPLC-ultraviolet method in combination with liquid-liquid extraction with isocratic elution was developed for the first time. The analysis was performed on a CLC-ODS column (6 mm internal diameter × 15 cm, 5 μm) using a mixture of acetonitrile and phosphate buffer (40:60, v/v) as the mobile phase at the flow rate of 1 mL/min. Using triamcinolone as the internal standard, 100 μL of plasma sample was extracted by methyl tert-butyl ether, followed by evaporating under nitrogen stream, re-dissolving with 100 μL mobile phase, and injection of 20-40 μL of supernatant into the chromatographic system. The linearity of DTG was good in the range of 0.05-10 μg/mL (r = 0.9995), and the inter- and intra-day variabilities were 0.4%-4.3% (n = 10) and 1.2%-6.2% (n = 10) for the lower limit of quantification, low-, medium-, and high-concentration quality control samples (0.05, 0.1, 0.8, and 8 μg/mL), respectively, while the methodological and extraction recoveries were 98.0%-103.0% (n = 20) and 65.2%-75.7% (n = 3), respectively. This method was successfully applied to analyze DTG plasma concentration in 84 Chinese patients with HIV.