Pharmaceutical Vehicles for Vaginal and Rectal Administration of Anti-HIV Microbicide Nanosystems

Prevention strategies play a key role in the fight against HIV/AIDS. Vaginal and rectal microbicides hold great promise in tackling sexual transmission of HIV-1, but effective and safe products are yet to be approved and made available to those in need. While most efforts have been placed in finding and testing suitable active drug candidates to be used in microbicide development, the last decade also saw considerable advances in the design of adequate carrier systems and formulations that could lead to products presenting enhanced performance in protecting from infection. One strategy demonstrating great potential encompasses the use of nanosystems, either with intrinsic antiviral activity or acting as carriers for promising microbicide drug candidates. Polymeric nanoparticles, in particular, have been shown to be able to enhance mucosal distribution and retention of promising antiretroviral compounds. One important aspect in the development of nanotechnology-based microbicides relates to the design of pharmaceutical vehicles that allow not only convenient vaginal and/or rectal administration, but also preserve or even enhance the performance of nanosystems. In this manuscript, we revise relevant work concerning the selection of vaginal/rectal dosage forms and vehicle formulation development for the administration of microbicide nanosystems. We also pinpoint major gaps in the field and provide pertinent hints for future work.

“Like Holding an Umbrella Before It Rains”: Acceptability of Future Rectal Microbicides Among Men Who Have Sex With Men in India—A Modified Technology Acceptance Model

Topical rectal microbicides (RMs) are a new prevention technology in development that aims to reduce the risk of HIV acquisition from anal sex. We examined RM acceptability among men who have sex with men (MSM) in India. We conducted a qualitative exploratory study guided by a modified Technology Acceptance Model, with 10 focus groups ( n = 61) of MSM and 10 key informant interviews. Data were explored using framework analysis. RM acceptability was influenced by technological contexts: perceived usefulness of RMs, perceived ease of use of RM and applicator, and habits around condom and lubricant use; individual and interpersonal contexts: perceived relevance and preferences for product formulation and dosing frequency; and MSM community/social contexts: perceived social approval, RM-related stigma, social support. Implementation of RMs for MSM in India may be supported by multi-level interventions that engage community-based organizations in destigmatizing and distributing RMs, ideally gel-based products that enable on-demand use before sex.

Antiretroviral pre-exposure prophylaxis preferences among men who have sex with men in Vietnam: results from a nationwide cross-sectional survey

Background The HIV/AIDS epidemic in Vietnam is concentrated in subgroups of the population, including men who have sex with men (MSM). Pre-exposure prophylaxis (PrEP) is a viable strategy for HIV prevention, but knowledge about and preferences for PrEP delivery among Vietnamese MSM are not well understood. Methods: In 2015, an online survey was conducted with recruitment via social networking websites for MSM and peer recruitment. A description of daily oral, long-acting injectable, and rectal microbicide formulations of PrEP was provided to participants. Participants were asked about their prior awareness of and interest in PrEP, and ranked their most preferred PrEP modality. Multivariable logistic regression models were used to assess factors associated with having heard of PrEP and preference for each PrEP modality. Results: Of 548 participants who answered demographic and PrEP-related questions, 26.8% had previously heard of PrEP and most (65.7%) endorsed rectal microbicides as their most preferred PrEP delivery modality. Commonly-cited perceived barriers to uptake of PrEP included concern about side-effects, perception about being HIV positive, and family or friends finding out about their sexual behaviour. In multivariable models, older participants less often endorsed rectal microbicides (adjusted odds ratio (AOR) 0.95 per year, 95% confidence interval (CI) 0.91–0.99) and more often endorsed long-acting injectables (AOR 1.08 per year, 95% CI 1.03 to 1.14) as their preferred PrEP modality. Participants who were willing to pay more for PrEP less often endorsed rectal microbicides (AOR 0.81, 95% CI 0.72–0.92) and more often endorsed long-acting injectables (AOR 1.17, 95% CI 1.01–1.35) and daily oral pills (AOR 1.16, 95% CI 1.00–1.35) as their preferred form of PrEP. Conclusions: A variety of PrEP modalities were acceptable to MSM in Vietnam, but low knowledge of PrEP may be a barrier to implementation.