Solid-phase microextraction for assessment of plasma protein binding, a complement to rapid equilibrium dialysis

Area of Science:

• Pharmacology
• Analytical Chemistry
• Biochemistry

Background:

• Plasma protein binding (PPB) is critical for understanding drug pharmacokinetics and pharmacodynamics.
• The free concentration of a drug determines its pharmacological activity.
• Accurate PPB measurement is vital for drug development and therapeutic efficacy.

Purpose of the Study:

• To investigate Solid-phase microextraction (SPME) as a method for determining plasma protein binding (PPB).
• To compare SPME's PPB measurements against the gold standard, rapid equilibrium dialysis (RED).
• To evaluate SPME as a potential alternative platform for PPB determination in biological matrices.

Main Methods:

• Solid-phase microextraction (SPME) technique was employed for PPB measurement.
• Comparison of SPME results with those obtained from rapid equilibrium dialysis (RED).
• Analysis of PPB for metoprolol, propranolol, and diclofenac across three concentrations.

Main Results:

• SPME-derived PPB values showed strong correlation with literature values.
• SPME results were comparable to those determined by RED.
• Average PPB percentages for metoprolol, propranolol, and diclofenac by SPME were 31.7%, 86.6%, and 99.0%, respectively, closely matching RED values.

Conclusions:

• SPME is a viable and accurate alternative method for determining plasma protein binding.
• The study provides evidence supporting SPME's utility in pharmacokinetic and pharmacodynamic assessments.
• SPME offers a promising platform for routine PPB determination in drug research.