Polyethylene Glycol- Based Hydrogels for Controlled Release of the Antimicrobial Subtilosin for Prophylaxis of Bacterial Vaginosis

Current treatment options for bacterial vaginosis (BV) have been shown to be inadequate at preventing recurrence and do not provide protection against associated infections, such as that with HIV. This study examines the feasibility of incorporating the antimicrobial peptide subtilosin within covalently cross- linked polyethyleneglycol (PEG)- based hydrogels for vaginal administration. The PEG- based hydrogels (4% and 6% [ wt/ vol]) provided a two- phase release of subtilosin, with an initial rapid release rate of 4.0 mu g/ h (0 to 12 h) followed by a slow, sustained release rate of 0.26 mu g/ h (12 to 120 h). The subtilosin- containing hydrogels inhibited thegrowth of the major BV- associated pathogengardnerella vaginalis with a reduction of 8 log(10) CFU/ ml with hydrogels containing >= 15 mu g entrapped subtilosin. In addition, thegrowth of four common species of vaginal lactobacilli was not significantly inhibited in the presence of the subtilosin- containing hydrogels. The above findings demonstrate the potential application of vaginal subtilosin- containing hydrogels for prophylaxis of BV.