Toxicological Assessment of the Cochleate Derived from Neisseria meningitidis Proteoliposome in Sprague Dawley Rats

BACKGROUND: The AFCo1 cochleate is a potential novel adjuvant derived from Neisseria meningitidis B proteoliposome. AIM: The aim was to assessing the safety of AFCo1 by single and repeated doses in Sprague Dawley rats. MATERIALS AND METHODS: Rats were grouped for treatment with AFCo1, placebo formulation or control. The first study was a single intranasal dose of 100 μl and monitoring body weight, water, and food intakes as well as clinical symptoms. Fourteen days later the rats were killed and anatomopathological studies were conducted. In a second study, four similar doses of the test substance were instilled every 5 days. Clinical observations were carried out as for the single dose study and a number of rats from each group were killed 3 and 14 days after the last dose in order to conduct hematological, hemochemical, and anatomopathological studies. RESULTS: No variable showed differences of toxicological relevance; the histological changes found were mild and similarly frequently in the three groups. According to the irritability index calculated form histology of the nasal region, AFCo1 was also classified as nonirritating. CONCLUSION: AFCo1 is potentially safe for human use by nasal route as evidenced by the absence of local and systemic signs of toxicity in Sprague Dawley rats.