High-Throughput LC-MS/MS Technique for Reliable Measurement of Posaconazole in Human Plasma

Abstract

A rapid and sensitive LC-MS/MS bioanalytical method was developed and validated for quantifying Posaconazole in human plasma using posaconazole D5 as the internal standard, per USFDA guidelines. Chromatographic separation employed a Waters Atlantis dC18 column (3µ, 4.6×50 mm) with a mobile phase of acetonitrile:5 mM ammonium formate containing 0.01% formic acid (95:5 v/v) at 0.6 mL/min flow rate, yielding retention times of 2.00 min for both analyte and IS.​ The method demonstrated excellent selectivity with no interference, linearity from 0.80 to 801.48 ng/mL, and robust in-system suitability (area ratio and S/N at LLOQ within limits). Precision and accuracy across six QC replicates met acceptance criteria, with consistent recovery at low, mid, and high levels, negligible matrix effects, and stability up to 18 hr for stock solutions, 3 days frozen for working solutions, 2 days/20 hr bench-top for spiked plasma, and 5 freeze-thaw cycles.​ This validated method supports reliable pharmacokinetic assessments and therapeutic drug monitoring of Posaconazole in clinical plasma samples. This LC-MS/MS approach addresses limitations of existing methods by offering superior sensitivity, high throughput, and cost-effectiveness for Posaconazole quantification, vital for ensuring therapeutic efficacy in antifungal therapy amid variable bioavailability challenges.