Pre-column derivatization method for determining phenylephrine in human plasma and its application in a...

Area of Science:

• Analytical Chemistry
• Pharmacology
• Biomedical Science

Background:

• Phenylephrine is a common decongestant, but accurate quantification in biological matrices is crucial for pharmacokinetic studies.
• Existing methods may lack the sensitivity or speed required for rapid clinical analysis.

Purpose of the Study:

• To develop and validate a rapid, sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for phenylephrine quantification in human plasma.
• To apply the validated method for pharmacokinetic analysis of phenylephrine in Chinese subjects with the common cold.

Main Methods:

• Pre-column derivatization of phenylephrine with dansyl-chloride in human plasma.
• Protein precipitation followed by liquid-liquid extraction using methyl tert-butyl ether-n-hexane.
• Analysis using a Gemini C18 column with a 3-minute gradient elution on a Waters TQ-s mass spectrometer.

Main Results:

• The method demonstrated linearity over a concentration range of 0.020 to 10.0 ng/mL, with a lower limit of quantification of 0.020 ng/mL.
• Excellent precision (<15% intra- and inter-day) and accuracy (95.0-105.3%) were achieved.
• The method was successfully applied to determine phenylephrine pharmacokinetics in Chinese subjects after single oral doses.

Conclusions:

• A robust and sensitive LC-MS/MS method for phenylephrine analysis in human plasma was successfully developed and validated.
• The method is suitable for pharmacokinetic studies, including those involving common cold treatments.
• The derivatization approach may be adaptable for analyzing endogenous catecholamines like norepinephrine and adrenaline.