Distribution of a 3.5-mL (1.0%) C31G vaginal gel using magnetic resonance imaging.

C31G (Savvy) has been developed as a topical vaginal microbicide with broad-spectrum antibacterial and antiviral properties. The objective of this study was to evaluate the distribution of a 1.0% concentration of (3.5 mL) C31G vaginal gel in the human pelvis using magnetic resonance imaging (MRI). Gel delivery with a standard applicator was primarily to the upper vagina and was well tolerated. Vaginal mucosal coverage at 18 min was excellent with 92% linear coverage and 75% surface contact coverage of the vagina. The upper vagina was almost completely covered and gel was also noted in the lower vagina. Coverage 6 h after application was substantially decreased, with 60% of maximal linear coverage and 41% surface contact. There was a very minimal coverage of the vaginal mucosa noted 24 h following insertion. Simulated intercourse resulted in relatively little change in overall distribution at all three time points. Repeat application of the gel may be necessary if intercourse has not occurred within the first few hours after initial insertion.