Safety and Efficacy of 0.5% Carbomer 980 Gel for Treatment of Symptoms of Common Cold: Results of 2 Randomized Trials

BACKGROUND: Two studies of intranasal 0.5% carbomer 980 gel were conducted evaluating nasal tolerability in healthy volunteers and safety and efficacy in adults with common cold symptoms. METHODS: Study 1 randomly assigned healthy adults to 0.5% carbomer 980 gel (n = 20) or placebo (n = 10) administered intranasally four times daily for 7 days. Nasal examinations were conducted at baseline and daily throughout the study. The primary endpoint was local nasal tolerability. Study 2 randomly assigned adults with an investigator-confirmed diagnosis of symptomatic common cold to 0.5% carbomer 980 gel (n = 87) or placebo (n = 81), administered intranasally four times daily for 7 days (except for day 1, where subjects who received their first dose mid-day administered only three doses). The primary efficacy endpoint was the average nasal symptom score over days 1‒4 (ANSS(1–4)). Secondary efficacy endpoints included ANSS over days 1‒7 and average total symptom score (ATSS). Adverse events (AEs) were recorded throughout the study. RESULTS: In study 1, subjects assigned to 0.5% carbomer 980 gel had no mucosal grading higher than grade 1B (superficial nasal mucosal erosion) and low incidences of mucosal bleeding and crusting. In study 2, there were no statistically significant differences between treatments for any efficacy endpoints. Active treatment was well-tolerated; the most commonly reported AEs were headache, myalgia, and cough. CONCLUSION: While 0.5% carbomer 980 gel nasal spray demonstrated good local nasal tolerability in healthy volunteers, the spray did not significantly impact the course of infection or resolution of cold symptoms in subjects with common cold.