Two formulations of azelastine nasal spray, the original (Astelin®; Meda Pharmaceuticals, Inc., Somerset, NJ) and a reformulated nasal spray (Astepro®; Meda Pharmaceuticals, Inc.), are currently indicated for treatment of seasonal allergic rhinitis. This randomized, double-blind study, conducted among professionally trained expert panelists in Sensory Descriptive Analysis, compared the original azelastine in a saline vehicle with the reformulated nasal spray in a sorbitol-based vehicle, focusing on bitterness of the two formulations. A total of 12 panelists were randomized to both doses (one or two sprays/nostril twice daily) of each azelastine formulation. The primary endpoint was the direct comparison of the bitterness of reformulated azelastine to original azelastine on a 15-point scale. At a dose of two sprays/nostril, there was a statistically significant 71% reduction in bitterness with reformulated azelastine versus original azelastine (P < 0.05). In addition, nasal discomfort was less frequent with reformulated azelastine versus original azelastine.