Fexofenadine is a second-generation, nonsedating antihistamine and pseudo-ephedrine is a decongestant. This combination is a popular treatment for relief of allergy symptoms. The analysis is difficult because the two drugs have very different hydrophobicities, but both are strong basic amines with a tendency to tail. Acclaim PolarAdvantage is well suited to this challenge as it delivers good base asymmetry over a wide range of mobile phase compositions. The short 4.6x50 mm format enables this analysis to be completed in less than 3.5 minutes.