Background
Dolutegravir is currently the preferred component of first-line antiretroviral therapy. To facilitate clinical pharmacology studies in key populations, quantitative analytical
Conclusions
The application of this simple, accurate, and precise method will expand opportunities for clinical assessment of dolutegravir in resource-limited settings.
Methods
Calibration standards and quality control samples were prepared by spotting 50 μL of dolutegravir-spiked whole blood on each circle of DBS cards. Three spots (two 6-mm punches/spot) were extracted with methanol. Chromatographic separation was achieved with gradient elution of acetonitrile/potassium phosphate monobasic buffer (pH 5) on a reverse-phase C18 column (flow rate, 1 mL/min) using pioglitazone as the internal standard. UV detection was performed at 260 nm. In the clinical pharmacokinetic study, DBS from finger prick was collected from participants (n = 10) at 8 time points over 12 hours postdosing, with paired plasma at 1 and 12 hours. The method was used to quantify dolutegravir, estimating pharmacokinetic parameters. Agreement between DBS and plasma concentrations was evaluated using linearity and Bland-Altman plots.
Results
The method was validated over the concentration range of 0.4-10 mcg/mL, accuracy was 102.4%-114.8%, and precision was 3.4%-14.7%. The mean recovery was 42.3% (%CV: 8.3). The mean (±SD) dolutegravir concentration in DBS was 37.5% (±3.8%) lower than that in the plasma. DBS-derived and measured plasma concentrations showed strong correlation with linearity (R2 = 0.9804) and Bland-Altman plots. Means (%CV) of area under curve, Cmax, and C24 from the DBS-derived plasma concentration were 37.8 (23.2) mcg·h/mL, 2.7 (24.7) mcg/mL, and 1.34 (31.6) mcg/mL, respectively. Conclusions: The application of this simple, accurate, and precise method will expand opportunities for clinical assessment of dolutegravir in resource-limited settings.