Determination of ribavirin in human serum using liquid chromatography tandem mass spectrometry

A method has been developed for the determination of ribavirin in human serum for therapeutic drug monitoring purposes, using liquid chromatography electrospray ionization mass spectrometry. Separation was obtained with a mobile phase gradient starting and ending in 100% aqueous conditions using a Waters Atlantis® T3 column (100 × 2 mm, 3 μm). The entire sample preparation consisted of dilution, followed by ultrafiltration. From the clear ultrafiltrate 5 μL was injected on the LC–MS/MS system. The calibration curves were linear in the range of 0.2–10 mg/L with within-run and between-run precisions (CVs) in the range of 0–10%. The method was validated with respect to specificity, selectivity, linearity, accuracy, precision, recovery and stability and meets the requirements of the FDA. The method was extensively tested for matrix effects by determining the variation of the slopes of calibration curves in different sources of serum and plasma. This method is suitable for the determination of ribavirin in human serum for therapeutic drug monitoring.