Validation and Clinical Application of a Liquid Chromatography Ultraviolet Detection Method to Quantify Dolutegravir in Dried Blood Spots.
BACKGROUND Dolutegravir is currently the preferred component of first line antiretroviral therapy. To facilitate clinical pharmacology studies in key populations, quantitative analytical methods compatible with microsampling and adaptable to resource limited settings are desirable. The authors developed and validated a liquid chromatography ultraviolet detection method to quantify dolutegravir in dried blood spots (DBS) METHODS Calibration standards and quality control samples were prepared by spotting 50 mL 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 h post dosing, with paired plasma at 1 and 12 h. 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 ug/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 standard deviation) 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 AUC, Cmax, and C24 from the DBS derived plasma concentration were 37.8 (23.2) mg.h/mL, 2.7 (24.7) mg/mL and 1.34 (31.6) mg/mL, respectively. CONCLUSIONS The application of this simple, accurate, and precise method will expand opportunities for clinical assessment of dolutegravir in resource limited settings.
Therapeutic drug monitoring