HPLC method for determination of verapamil in human plasma after solid-phase extraction

Area of Science:

• Analytical Chemistry
• Pharmacokinetics

Background:

• Verapamil is a crucial calcium channel blocker used in treating cardiovascular conditions.
• Accurate quantification of verapamil in biological matrices like plasma is essential for pharmacokinetic studies and therapeutic drug monitoring.

Purpose of the Study:

• To develop and validate a simple, rapid, and precise High-Performance Liquid Chromatography (HPLC) method for the assay of verapamil in human plasma.

Main Methods:

• Solid-phase extraction (SPE) using mixed-mode (hydrophilic-lipophilic balance - HLB) cartridges for plasma sample cleanup.
• Isocratic elution HPLC separation on a Lichrospher 60 RP-select B column.
• Detection at 200 nm with diltiazem as the internal standard.

Main Results:

• Optimal sample recovery (94.70-103.71%) achieved with HLB cartridges.
• Linear calibration curves obtained in the range of 10-500 ng/mL.
• The method demonstrated high precision and accuracy suitable for routine analysis.

Conclusions:

• A robust and efficient HPLC method for verapamil quantification in human plasma has been successfully developed.
• The method's simplicity, speed, and precision make it suitable for routine clinical and research applications.