Pharmaceutical formulations used to treat the common cold often contain multiple active ingredients to treat different symptoms. These actives can include combinations of decongestants, antihistamines, pain relievers, cough suppressants and expectorants in addition to numerous excipients, all of which exhibit different chemical properties, including polarity. It is this range of analyte polarity that often makes chromatographic methods development difficult.
In this study, we used Waters UltraPerformance LC (UPLC) technology to develop a single chromatographic method for the analysis of the most common pharmaceutical formulations targeted to relieve symptoms associated with the common cold. Utilizing UPLC for this analysis improves productivity by enabling the separation of such complex mixtures while maintaining a high level of chromatographic resolution in a rapid analysis time.
We used a new High Strength Silica (HSS) UPLC stationary phase to develop a single chromatographic method for the analysis of a number of possible formulation compositions. This stationary phase was selected due to its ability to enhance the retention of polar analytes while also having good chromatographic selectivity of hydrophobic species. This methodology was then applied to several over-the-counter (OTC) formulations to quantitate the accuracy of reported concentrations of the active ingredients.