A Robust and Accurate Filter Paper-Based Dried Plasma Spot Method for Bictegravir Monitoring in HIV Therapy

Area of Science:

• Pharmacology
• Analytical Chemistry
• Biochemistry

Background:

• Therapeutic drug monitoring (TDM) traditionally requires large volumes of blood or plasma.
• Minimizing biological sample collection is crucial for patient comfort and study feasibility.
• Dried blood spot (DBS) and dried plasma spot (DPS) techniques offer potential for reduced sample volumes.

Purpose of the Study:

• To develop a novel method for determining plasma bictegravir levels using dried plasma spots.
• To establish a robust assay for quantifying an HIV integrase strand transfer inhibitor (INSTI) from minimal plasma samples.
• To validate a cost-effective and accurate technique for bictegravir TDM.

Main Methods:

• Quantification of bictegravir in dried plasma spots using liquid chromatography-tandem mass spectrometry (LC-MS/MS).
• Extraction of bictegravir from 60 µL of plasma spotted onto filter paper using methanol.
• Analysis of drug concentration within a linear range of 20-1200 ng/mL.

Main Results:

• The developed extraction technique achieved a 100% recovery rate.
• The assay demonstrated excellent linearity across the specified concentration range.
• The method proved effective for detecting and quantifying bictegravir in dried plasma samples.

Conclusions:

• The novel method provides a robust, simple, and accurate approach for drug extraction from plasma.
• This technique enables cleaner sample preparation, reducing costs and improving accuracy.
• The dried plasma spot method is a viable alternative for bictegravir therapeutic drug monitoring.