Method development for simultaneous determination of active ingredients in cough and cold pharmaceuticals by high...

A rapid, simple and efficient liquid chromatographic method was developed for simultaneous determination of three active ingredients namely, chlorpheniramine maleate, phenylephrine hydrochloride and guaifenesin along with sodium benzoate preservative common cold medications (syrups) and the method was validated based on the International Conference on Harmonization (ICH) and United State Pharmacopeia (USP) guidelines. Separation of the analytes was achieved within 15 min on a nucleosil gravity phenyl column in a single run with a mobile phase consisting of methanol: buffer mixture (15:85 v/v) at room temperature, in isocratic mode with flow rate of 0.8 mL min^-1. A comprehensive study on specificity, range, accuracy (recovery), intraday and interday precisions, limit of detection, limit of quantitation, robustness, ruggedness, system suitability and specification was performed as a part of method validation. The linearity was obtained in the range of 7.1-12.2 μg mL^-1 (r² = 0.9984), 17.6-30.1 μg mL^-1 (r² = 0.9995), 39.6-67.8 μg mL^-1 (r² = 0.9995) and 351.1-601.8 μg mL^-1 (r² = 0.9996) for chlorpheniramine maleate, phenylephrine hydrochloride, sodium benzoate and guaifenesin, respectively. The proposed liquid chromatographic method was successfully applied for the routine analysis of these compounds in different commercial cough and cold pharmaceutical preparations including syrups with no interference from the excipients.