Charge-transfer complexes of phenylephrine with nitrobenzene derivatives

Area of Science:

• Analytical Chemistry
• Pharmaceutical Analysis

Background:

• Phenylephrine hydrochloride is a common pharmaceutical agent.
• Accurate quantification methods are crucial for quality control.

Purpose of the Study:

• To develop simple and selective methods for determining phenylephrine hydrochloride.
• To investigate charge-transfer complex formation for analytical applications.

Main Methods:

• Spectroscopic analysis (IR, 1H NMR, electronic spectra) of charge-transfer complexes.
• UV-Vis spectrophotometry for quantification in bulk and tablet forms.
• Kinetic investigation of the oxidation reaction with alkaline potassium permanganate.

Main Results:

• Charge-transfer complexes formed with picric acid and m-dinitrobenzene showed distinct absorption maxima (497 nm and 560 nm in acetonitrile, respectively).
• A colored product with an absorption maximum at 650 nm was observed in dioxane.
• Sensitive kinetic methods based on oxidation were established for phenylephrine hydrochloride determination.

Conclusions:

• Charge-transfer complexation provides a viable basis for spectrophotometric determination of phenylephrine hydrochloride.
• Kinetic methods offer sensitive and selective approaches for drug analysis.