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.


The development of a new azelastine nasal spray formulation with less bitterness began with studies that used an electronic sensing device (Alpha M.O.S. America, Hillsborough, NJ) to evaluate the degree of bitterness of several investigational formulations. These studies tested a number of different combinations of vehicles and taste-masking agents to produce a formulation with the stability and isotonicity of the original azelastine formulation, with a reduction in bitter taste. The electronic sensing device identified candidate formulations for testing in humans. The formulations with the potential for improved tolerability were administered orally and then intranasally. Historically, the pharmaceutical industry has relied on taste analysis via in vitro methods, such as the electronic sensor, as well as human taste panels to evaluate liquid samples. Based on our current study, these methodologies appear appropriate for intranasal preparations as well.