A bridging study was performed to compare the safety, dose delivery, and acceptability of a prefilled plastic and user-filled paper applicator to assess whether a low-cost, user-filled, paper applicator could serve as a delivery option for tenofovir (TFV) 1% vaginal microbicide gel.
The study used a randomized crossover design with 25 healthy women randomized to begin with the prefilled or user-filled applicator. Within each study arm, participants delivered two 4.0-mL doses of TFV 1% gel vaginally for 7 days, with one dose delivered at the clinic each morning and a second dose delivered at home each evening. To assess the primary objective, applicator safety, colposcopy examinations were performed at 2 time points in each study arm.
There were no colposcopic findings or adverse events attributable to either applicator. One case of vulvovaginal candidiasis was considered possibly related to gel use. On average, the user-filled applicator delivered 96% of the target dose, with 85% of doses falling within ±10% of the average dose volume. Participants found both applicators comparable for ease of use, insertion, and dispensing gel, with 60% of participants preferring the user-filled applicator.
This study suggests that both applicators are safe, and most women delivered TFV with the user-filled applicator as directed. Participants found both applicators acceptable, with a slight majority preferring the user-filled applicator. Incorporating a low-cost, user-filled, paper applicator to deliver TFV could help reduce costs and improve access to TFV 1% gel, especially in resource-limited settings heavily impacted by HIV.