Quantification of The Anti-Influenza Drug Zanamivir in Plasma Using High-Throughput Hilic–MS/MS

Background: Parenteral zanamivir is a promising drug for the treatment of severe influenza. However, quantification of this polar drug in biological matrices has traditionally been difficult and the methods developed have been relatively insensitive. Results: A high-throughput bioanalytical method for the analysis of zanamivir in human plasma using SPE in the 96-well plate format and LC coupled to positive MS/MS has been developed and validated according to US FDA guidelines. The method uses 50 µl of plasma and covers a large working range from 1–50, 000 ng/ml with a LOD of 0.50 ng/ml. Conclusion: This new LC–MS/MS assay is more sensitive than previous methods despite using a small plasma volume sample. It is particularly suitable for clinical studies on both parenteral and inhaled zanamivir.