Simultaneous Determination of Acetaminophen, Caffeine, and Chlorphenamine Maleate in Paracetamol and Chlorphenamine Maleate Granules

Abstract

A simple and rapid HPLC method using phenacetin (PHN) as internal standard has been developed for simultaneous determination of acetaminophen, caffeine, and chlorphenamine maleate in the product compound paracetamol and chlorphenamine maleate granules. Separation and quantitation were achieved on a 250 mm × 4.6 mm, 5 μm particle, C₁₈ column. The mobile phase was methanol 0.05 mol L⁻¹ aqueous KH₂PO₄ solution, 45:55 (v/v), containing 0.1% triethylamine and adjusted to pH 3.6 by addition of phosphoric acid; the flow rate was 1.0 mL min⁻¹. Detection of all compounds was by UV absorbance at 260 nm and elution of the analytes was achieved in less than 12 min. The linearity, accuracy, and precision of the method were acceptable to good over the concentration ranges 6.4–153.6 μg mL⁻¹ for acetaminophen, 5.0–120.0 μg mL⁻¹ for caffeine, and 9.6–230.4 μg mL⁻¹ for chlorphenamine maleate.