Quantification of Anions in Pharmaceuticals

This Application Note describes the use of two anionexchange columns with suppressed conductivity detection to analyze common anions in pharmaceutical formulations. Two oral, over-the-counter medications were selected as representative pharmaceutical products: a cough suppressant and a multisymptom cold/flu medication. These formulations contain complex mixtures of ingredients that are commonly found in other medications, many of which are ionic and nonchromophoric. Furthermore, these formulations also contain sugar alcohol, glycol, and carbohydrate ingredients that can be analyzed using the IonPac® ICE-AS1, CarboPac™ MA1, and CarboPac PA10 columns with electrochemical detection. In the methods outlined in this Note, the selectivities of the IonPac AS14 and AS11 columns for the analysis of anionic ingredients in pharmaceutical formulations were compared.