Colposcopic evaluation of a vaginal gel formulation of iota-carrageenan.

There is an urgent need to develop safe, effective, and acceptable vaginal products for the prevention of sexually transmitted infections. Preliminary in vitro results suggest that vaginal formulations of sulfated polysaccharides, including iota-carrageenan, have the potential to block mucosal transmission of human immunodeficiency virus (HIV). Twenty-five women in five sites participated in Phase I trials to evaluate the safety of a formulation containing iota-carrageenan (PC 213). The results of this study indicate that a 5 mL 2% gel formulation of iota-carrageenan is not associated with significant irritation of the female reproductive tract when administered once daily in the absence of sexual intercourse. Given the small number of participants in this initial study, careful observation for potential irritation must also be included in larger studies of this and other vaginal formulations.