LC-MS/MS Method Validation for Quantification of Nirmatrelvir in Human Plasma

Area of Science:

• Analytical Chemistry
• Pharmacokinetics
• Biotechnology

Background:

• Accurate monitoring of nirmatrelvir, a critical COVID-19 antiviral, is essential for therapeutic optimization.
• Existing methods may lack the sensitivity or specificity required for robust drug level assessment.

Purpose of the Study:

• To develop and validate a sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for quantifying nirmatrelvir in human plasma.
• To establish a reliable tool for pharmacokinetic evaluation of nirmatrelvir in clinical settings.

Main Methods:

• Quantification of nirmatrelvir using LC-MS/MS with nirmatrelvir-D9 as an internal standard.
• Selected reaction monitoring (SRM) in positive electrospray ionization mode.
• Streamlined sample preparation involving phospholipid removal for high-throughput processing.

Main Results:

• The validated method demonstrated a wide linear range (10.9–3013 ng/mL) and high precision (intra- and interassay <15%).
• The assay met all bioanalytical guideline criteria for matrix effect, carryover, dilution integrity, and stability.
• Rapid analysis time of 2 minutes per sample achieved.

Conclusions:

• The developed LC-MS/MS method is sensitive, specific, accurate, and reproducible for nirmatrelvir quantification.
• This validated assay is suitable for routine clinical monitoring and pharmacokinetic studies of nirmatrelvir.
• The method's efficiency supports high-throughput analysis in clinical settings.