Statistical Optimization of Reverse Phase High Performance Liquid Chromatography for the Analysis of Caffeine Paracetamol and its Degradation Product p-aminophenol

Paracetamol, analgoantipyretic and anti-inflammatory drug, is available in numerous pharmaceutical formulations in common combination with caffeine and some other drug substances. p-aminophenol is paracatamol’s process-related impurity that also may be present in formulations containing paracetamol. This paper presents a RP-HPLC method for simultaneous determination of caffeine, paracetamol and p-aminophenol, using chromatographic system Hewlett Packard 1100 series. In defining optimal RP-HPLC chromatographic conditions for the separation of these three compounds, experimental design was applied. Completely separation was achieved using Zorbax Extend C18 column (150 mm × 4.6 mm, 5 μm), with mobile phase consisting of methanol-phosphate buffer pH 6 (20:80 v/v), flow rate of 1 ml/min, and column temperature of 30 °C. UV detection was performed at 230 nm.