The evaluation of the local tolerance of vaginal formulations, with or without nonoxynol-9, using the slug mucosal irritation test

Background: Frequent use of some vaginal formulations can induce mucosal irritation. Therefore, it is important to evaluate their vaginal tolerance. Goal: The goal of this study was to optimize the mucosal irritation test using slugs for the evaluation of the local tolerance of vaginal gels and investigate the relevance of the test. Study Design: The irritation potential of the gels was assessed by the amount of mucus produced during a repeated 30-minute contact period. Membrane damage was estimated from the release of proteins and enzymes. After optimization of the procedure, the local tolerance of several vaginal gels was evaluated. Results: Hydroxyethyl cellulose gel induced no irritation, because the mucus production and the protein release were low and no enzyme release was detected. Replens and K-Y jelly resulted in an increased mucus production; however, no increased protein and no enzyme release were detected. The nonoxynol-9-containing gels Protectaid, Advantage S, and Conceptrol caused a higher mucus production and an increased protein release and/or enzyme release, indicating severe irritation. Conclusion: The mucosal irritation test using slugs can be used for local tolerance testing of vaginal formulations.