High-Performance Liquid Chromatography Method for Simultaneous Determination of Guaifenesin, Salbutamol Sulfate and Guaifenesin Impurity (Guaiacol).

A simple and reliable HPLC method is developed for isocratic separation of a ternary mixture of Salbutamol Sulfate (SAL), Guaifenesin (GUI) and its impurity Guaiacol (GUA) either in pure powder or in pharmaceutical formulation. Chromatographic separation was applied on a Hypersil GOLD CN column with a mobile phase consisting of 0.05 M KH2PO4 (containing 0.1% triethylamine, pH adjusted to 3.7 by phosphoric acid): methanol (60: 40 by volume) using 0.6 mL min-1 flow rate and detection of peaks at 275 nm at 25°C with run time around 6 min. The calibration plots were linear over the concentration ranges of 0.5-20, 0.5-30 and 0.1-10 µg mL-1 for SAL, GUI and GUA, respectively. ICH guidelines were used for the validation of presented method. The obtained results were compared with the results obtained from the reported HPLC method and no significant difference was found regarding accuracy and precision.