Vaginal Microbicides Research Articles

Women design their own vaginal microbicide trial: Suggestions on how to improve adherence from former participants of HIV prevention trials.

Low adherence in vaginal microbicide clinical trials for HIV prevention has impeded interpretation of trial results and hindered evaluation of potentially efficacious HIV prevention gels. Understanding the underlying reasons why women join trials and their barriers to product use can support identification of ways to improve adherence and its reporting. Eight focus group discussion workshops were conducted with 46 former microbicide trial participants in Durban, South Africa and Mwanza, Tanzania. Participants provided feedback on why women join trials, the barriers to using study gel and reporting adherence accurately, and how clinical trial design can be improved to support better adherence and its reporting. Women join microbicide trials for a number of important reasons such as healthcare and financial reimbursement. Fear of adverse effects from the investigational product was the most important reason why participants reported not using the gel. The key reason for inaccurate reporting of gel use was fear of removal from the trial. Participants made concrete suggestions for improving microbicide trial design such as applicator use testing and real time feedback, improving education to participants about how trials answer their research questions, and improving transparency and clarity about study procedures. Participants also gave feedback on an innovative trial design with a non-randomised arm. Identifying HIV prevention products for women requires better understanding of the lives of women asked to join these trials, and application of that understanding to microbicide trial design. This study has demonstrated that participants and research teams can work collaboratively to design clinical trials that meet needs of both the research and of participants.

The dapivirine vaginal ring from the perspective of married men in Uganda

Background: Men play a key role in influencing uptake of women’s health products, such as female condoms and vaginal microbicides used for family planning and HIV prevention. Method: We explored men’s perceptions of the dapivirine vaginal ring (DVR), a vaginal microbicide, in Kalungu District, rural south-western Uganda. In June/July 2018, we conducted in-depth interviews with 10 partners of women participating in the DREAM study, a phase 3B open-label extension trial of the DVR. Data were analysed thematically, drawing on the socio-ecological model theoretical framework. Results: Influencing factors such as individual and interpersonal characteristics, perception of HIV risk, lack of knowledge about the DVR, misconceptions, and product characteristics acting at different levels (individual, societal and organisational) affected men’s knowledge, attitudes and perceptions towards the DVR, which in turn impacted on their willingness to allow their partners to use it. Above all, men wanted to be involved in the decision- making process about the use of the DVR. All the men were happy that there was a new HIV prevention option in the pipeline and were not concerned about the degree of effectiveness, saying it was better than nothing. Conclusion: The use of the DVR in an environment where men expect to make decisions about sex on behalf of women may affect its usage and success. Given this context, women may not always be able to independently choose to use it. If the DVR is approved and rolled out, increased sensitisation of men about it will be critical to ensure its uptake.

Potential of mucoadhesive chitosan glutamate microparticles as microbicide carriers – antiherpes activity and penetration behavior across the human vaginal epithelium

Chitosan glutamate (gCS) spray-dried microparticles appear promising carriers to overcome challenges associated with vaginal microbicide delivery. This study aimed at elucidating the penetration and mucoadhesive behavior of developed gCS multiunit carriers with zidovudine (ZVD) as a model antiretroviral agent in contact with excised human vaginal epithelium followed with an examination of in vitro antiherpes activity in immortal human keratinocytes HaCaT and human vaginal epithelial cells VK2-E6/E7. Both ZVD dispersion and placebo microparticles served as controls. Microparticles displayed feasible (comparable to commercial vaginal product) mucoadhesive and mucoretention characteristics to isolated human vaginal tissue. Ex vivo penetration studies revealed that gCS increased the accumulation of active agent in the vaginal epithelium but surprisingly did not facilitate its penetration across human tissue. Finally, the obtained antiviral results demonstrated the potential of gCS as an antiherpes adjunctive, whose mode of action was related to blocking viral attachment.

Development of pH-sensitive vaginal films based on methacrylate copolymers for topical HIV-1 pre-exposure prophylaxis

Interest is growing in “smart” vaginal microbicides as a strategy to protect women from sexual transmission of human immunodeficiency virus (HIV). The concept is based on the development of products featuring low drug release in acidic media such as vaginal fluid but switch to a fast release profile when the medium becomes neutral or slightly alkaline. This mimics the surge in pH occurring in the vagina after sexual intercourse due to the seminal fluid. Semen is the main vehicle for HIV-1, and increasing antiretroviral drug levels in the vagina upon ejaculation may contribute to enhanced protection against viral sexual transmission. This work explores the use of different pharmaceutical-grade methacrylic acid-based polymers (EudragitⓇ RL, RS, L and S) for developing vaginal films allowing the pH-dependant release of the antiretroviral drug tenofovir (TFV). EudragitⓇ L 100 and EudragitⓇ S 100, containing triethyl citrate as plasticiser, proved to be suitable for manufacturing films with optimal dual in vitro drug-release behaviour. TFV-release can be sustained for several days after film administration and all the drug is released in a few hours in conditions simulating ejaculation. The films’ mechanical properties were also deemed suitable for comfortable vaginal administration. Two optimized films were further assessed using HEC-1-A and Ca Ski cell monolayer models and were found to possess favourable drug permeability profiles and drug levels associated to cell monolayer as compared to free TFV. Overall, pH-dependant films containing tenofovir may constitute promising candidates for “smart” vaginal microbicides to protect women from sexual HIV transmission.

Emergence of Nanotechnology to Fight HIV Sexual Transmission: The Trip of G2-S16 Polyanionic Carbosilane Dendrimer to Possible Pre-Clinical Trials.

Development of new, safe, and effective microbicides to prevent human immunodeficiency virus HIV sexual transmission is needed. Unfortunately, most microbicides proved ineffective to prevent the risk of HIV-infection in clinical trials. We are working with G2-S16 polyanionic carbosilane dendrimer (PCD) as a new possible vaginal topical microbicide, based on its short reaction times, wide availability, high reproducibility, and quantitative yields of reaction. G2-S16 PCD exerts anti-HIV activity at an early stage of viral replication, by blocking gp120/CD4/CCR5 interaction, and providing a barrier against infection for long periods of time. G2-S16 PCD was stable at different pH values, as well as in the presence of seminal fluids. It maintained the anti-HIV activity against R5/X4 HIV over time, did not generate any type of drug resistance, and retained the anti-HIV effect when exposed to semen-enhanced viral infection. Importantly, G2-S16 PCD did not modify vaginal microbiota neither in vitro or in vivo. Histopathological examination did not show vaginal irritation, inflammation, lesions, or damage in the vaginal mucosa, after administration of G2-S16 PCD at different concentrations and times in female mice and rabbit animal models. Based on these promising data, G2-S16 PCD could become a good, safe, and readily available candidate to use as a topical vaginal microbicide against HIV.

Nanotechnology-Based Platforms for Vaginal Delivery of Peptide Microbicides.

Vaginal drug delivery offers an opportunity for effective microbicide treatments. However, the physiological characteristics of the vagina represent a challenge when preparing microbicide formulations for local delivery that avoid systemic effects. To review recent advances in vaginal microbicides placing special emphasis on nanocarriers that encapsulate peptide microbicides. The review includes an overview of local treatment and prevention strategies for bactericidal, fungal, protozoal and viral vaginal infections that use peptide microbicides. Scientific literature and clinical trials published in the PubMed database since 2015 are analyzed. Peptide microbicides are used for vaginal drug delivery as a means of prevention and treatment of several infectious diseases, especially sexually transmitted infections, and it is clear that such peptide-based microbicides constitute a suitable strategy. Their combination with nanotechnological drug delivery systems improves local peptide administration while avoiding their degradation and adverse effects. To date, only a few polymeric and lipid-based nanocarriers have been used for peptide microbicide vaginal delivery. The combination of nanotechnology and peptide microbicides has emerged over recent years, and different platforms are being used for vaginal peptide delivery. Nanostructured systems for peptide delivery via vaginal rings or hydrogels are increasingly used as platforms capable of providing suitable drug delivery. However, there is still a lack of knowledge about nanocarriers aimed at encapsulating peptides for local microbicide delivery.

Prevention, Partners, and Power Imbalances: Women's Views on How Male Partners Affected Their Adherence to Vaginal Microbicide Gels During HIV Prevention Trials in Africa.

Low adherence has contributed to disappointing results for trials testing vaginal microbicides for HIV prevention. This study engaged former gel trial participants to understand the reasons behind low adherence and seek suggestions on how to improve products and adherence to microbicides. This analysis examines the impact of participant perceptions of male partners on participant adherence and suggestions on how to address those issues. Eight focus group discussion workshops were conducted with 46 former microbicide trial participants in South Africa and Tanzania. Participants provided feedback on why women join trials, barriers to using gels and reporting adherence accurately, and how adherence and adherence reporting can be improved. Participants reported that male partners can affect women's ability to use gels. For some, the lubricating effects caused relationship conflicts due to suspicion of male partners about infidelity. Needing to provide sex to partners on demand was a barrier to gel use. Participants suggested a gel formulation which was thicker and less noticeable, and explicit male partner engagement to enhance understanding of the purpose of the gels. The imbalance of power in intimate relationships affects the ability of women to use microbicides as directed. To improve adherence to HIV prevention methods within trials and for successful rollout of proven HIV prevention methods in populations, it is important that the complicated dynamics of sex and relationships be taken into greater consideration and that women receive targeted support to navigate product use and communication within the context of these gender dynamics.

The Role of Volume in the Perceptibility of Topical Vaginal Formulations: User Sensory Perceptions and Experiences of Heterosexual Couples During Vaginal Sex.

Users' sensory perceptions and experiences (USPEs; perceptibility) of drug formulations can critically impact product adoption and adherence, especially when products rely on appropriate user behaviors (timing of administration, dosing measurement) for effectiveness. The use of topical gel formulations for effective antihuman immunodeficiency virus/sexually transmitted infection (HIV/STI) vaginal microbicides has been associated with messiness and other use-associated challenges, resulting in low adherence. Nonetheless, such formulations remain attractive due to good pharmacokinetics and resulting pharmacodynamics through their volume and surface contact for drug delivery into luminal fluids and mucosa. Consequently, advocates and scientists continue to pursue topical forms [semisolid (e.g., gel, suppository); solid (e.g., film)] to deliver select drugs and offer user choice in HIV/STI prevention. The current data build on previously validated USPE scales evaluating perceptibility of gels with various biophysical/rheological properties. Specifically, increased formulation parameter space adds a new set of properties inherent in quick-dissolving film. We compared film, a product adding no discernable volume to the vaginal environment, to 2 and 3.5 mL hydroxyethyl cellulose gel to consider the impact of volume on user experience. We also examined the USPE scales for evaluation of male sexual partners' experiences. The original USPE scales functioned as expected. Additionally, six new USPE scales were identified in this enhanced parameter space. Significant differences were noted between USPEs in pairwise comparisons, with largest differences between film and high-volume gel. Product developers and behavioral scientists can use these scales to design products, optimizing user experience and maximizing adherence and delivery of efficacious anti-HIV/STI pharmaceuticals. They can be extended to evaluation of additional formulations, devices, and compartments, as well as single- and multipurpose pharmaceuticals. In broader contexts, USPEs could be of value in evaluating formulations and devices to prevent/treat other diseases (e.g., ophthalmologic, dermatologic). Steadfast attention should be given to patient experience, and, where applicable, experiences of partners and/or caregivers.

Sharing Objective Measures of Adherence to a Vaginal Microbicide Promotes Candor About Actual Use and Bolsters Motivation to Prevent HIV.

Discrepancies between self-reported and actual adherence to biomedical HIV interventions is common and in clinical trials can compromise the integrity of findings. One solution is to monitor adherence biomarkers, but it is not well understood how to navigate biomarker feedback with participants. We surveyed 42 counselors and interviewed a subset of 22 to characterize their perspectives about communicating with participants about residual drug levels, an objective marker of adherence, within MTN-025/HOPE, a Phase 3b clinical trial of a vaginal ring to prevent HIV. When biomarkers indicated low drug levels that mismatched high adherence by self-report, counselors encountered barriers to acceptance and comprehension among participants. However, discrepancies between low self-report and higher drug levels generally stimulated candor. Women recollected times they had not used the product and disclosed problems that counselors thought might otherwise have remained forgotten or concealed. Navigating conversations toward HIV prevention was easier at mid-range drug levels and when women indicated motivation to prevent HIV. Ratings of residual drug level offered a somewhat objective measure of adherence and protection that counselors perceived as meaningful to participants and as a valuable catalyst for broaching conversation about HIV prevention. However, communication about drug levels required that counselors navigate emotional barriers, respond skillfully to questions about accuracy, and pivot conversations non-judgmentally away from numerical results and toward the priority of HIV prevention. Findings suggest a role for biomarker feedback in future clinical trials as well as other clinical contexts where biomarkers may be monitored, to motivate disclosure of actual adherence and movement toward HIV prevention.Clinical Trial Number NCT02858037.

Preferences and Acceptability of Vaginal Delivery Forms for HIV Prevention Among Women, Male Partners and Key Informants in South Africa and Zimbabwe: Qualitative Findings.

The attributes of an HIV microbicide may affect its acceptability, uptake and use. Quatro, a clinical study with a qualitative component, was conducted to elicit input from end-users and key informants (KIs) on four different placebo vaginal microbicide delivery forms; fast dissolving insert, ring, film and gel. In-depth interviews and focus group discussions were conducted with young women, their male partners and KIs, to explore acceptability and preferences of the four placebo products, with the intention of improving product attributes, adherence, and consequently, long term effectiveness. None of the four microbicide delivery forms stood well above others as the most preferred. Product attributes; long-action, ease of use, invisibility, female initiated and non-interference during sex were favourable in both countries. Despite preference for the long-action, on-demand products were the most liked by women. Qualitative data from the Quatro study provided rich feedback on specific attributes important to the acceptability of four HIV prevention product platforms currently in development, enabling more informed and guided product development efforts moving forward.

Efavirenz nanomicelles loaded vaginal film (EZ film) for preexposure prophylaxis (PrEP) of HIV

Preexposure prophylaxis (PrEP) using oral or vaginal microbicide is an emerging and effective strategy to prevent HIV transmission. Vaginal film is becoming more acceptable and a convenient dosage form compared to cream, gel and suppository. Extremely poor aqueous solubility of efavirenz (EFV) limits its use as vaginal microbicide. The aim of this study was to develop and evaluate a monomeric surfactant free, rapidly soluble vaginal film of EFV (EZ film). EZ film was prepared using a tetrafunctional block polymer (Tetronic 1107), carrageenan and polyvinyl alcohol (PVA) by solvent evaporation method. First, different solubilizers were screened for EFV solubility, in vitro cytotoxicity and cell membrane integrity assay on HeLa cells. Optimized film was characterized for solid state, mechanical strength, epithelial integrity, in vitro drug release in simulated vaginal fluid (SVF), simulated seminal fluid (SSF) and in vitro anti-HIV activity. Optimized EZ film showed a particle size of 48 ± 3.8 nm with PDI of 0.299. Differential scanning colorimetry (DSC) thermogram suggested the complete amorphization of EFV within the film. EZ film rapidly disintegrated (30 s) with complete release of EFV in SVF and SSF. The film was found to be non-toxic to HeLa cells and showed similar anti-HIV-1 activity as that of EFV in DMSO. EZ film did not show any significant change in the TEER value in HEC 1A cell line. Hence, the findings from the current study strongly suggest that the EZ film could be a cost-effective and convenient dosage form for PrEP of HIV.

Effectiveness of vaginal microbicides in preventing HIV transmission.

To evaluate the evidence on the effectiveness of vaginal microbicides in preventing HIV transmission in women. Systematic review through a comprehensive search of relevant electronic databases for eligible randomised controlled trials (RCTs) published through June 2019. Two authors independently screened titles and abstracts according to eligibility criteria, then extracted data and assessed risk of bias of included studies. We conducted a random-effects meta-analysis of risk ratios (RR) of HIV infection and assessed heterogeneity using chi-squared and I2 tests. Sources of heterogeneity were investigated through subgroup analysis, publication bias was assessed using funnel plots, and certainty of evidence was graded using GRADEPro software. We included 18 RCTs which enrolled 40,048 sexually active, HIV-negative, non-pregnant women, aged 16years and older, mainly from sub-Saharan Africa. The intravaginal ring containing dapivirine significantly reduced HIV risk by 29% (RR 0.71, 95% CI: 0.57-0.89; 2 RCTs, 4,564 women, moderate certainty of evidence). Estimates of effect of tenofovir 1% (RR 0.83, 95% CI: 0.65-1.06), nonoxynol-9 (RR 1.15, 95% CI: 0.93-1.42), cellulose sulphate (RR 1.16, 95% CI: 0.61-2.21), SAVVY (RR 1.34, 95% CI: 0.69-2.59), Carraguard (RR 0.89, 95% CI: 0.71-1.10), BufferGel (RR 1.02, 95% CI: 0.71-1.46), 0.5% PRO2000 (RR 0.88, 95% CI: 0.60-1.28) and 2% PRO2000 (RR 0.81, 95% CI: 0.58-1.12) failed to reach statistical significance; each had low certainty of evidence. The long-acting intravaginal ring containing dapivirine significantly reduced risk of HIV transmission in women by 29%. The remaining microbicides had no evident effect.

Carrageenan-Based Acyclovir Mucoadhesive Vaginal Tablets for Prevention of Genital Herpes.

Women are the most affected by genital herpes, which is one of the most common sexually transmitted infections, affecting more than 400 million people worldwide. The application of vaginal microbicides could provide a safe method of protection. Acyclovir is a safe and effective medication for vaginal administration, and numerous benefits have been observed in the treatment of primary or recurrent lesions due to genital herpes. Vaginal tablets based on a combination of the polymers iota-carrageenan and hydroxypropyl methylcellulose were developed for the controlled release of acyclovir. Swelling, mucoadhesion and drug release studies were carried out in simulated vaginal fluid. The tablets, containing a combination of iota-carrageenan and hydroxypropyl methylcellulose, have an adequate uptake of the medium that allows them to develop the precise consistency and volume of gel for the controlled release of acyclovir. Its high mucoadhesive capacity also allows the formulation to remain in the vaginal area long enough to ensure the complete release of acyclovir. These promising formulations for the prevention of genital herpes deserve further evaluation.

Mucoadhesive Vaginal Discs based on Cyclodextrin and Surfactants for the Controlled Release of Antiretroviral Drugs to Prevent the Sexual Transmission of HIV.

The strategies for developing vaginal microbicides to protect women against human immunodeficiency virus (HIV) sexual transmission are constantly changing. Although the initial dosage forms required daily administration to offer effective protection, the trend then moved towards sustained-release dosage forms that require less frequency of administration in order to improve women’s compliance with the treatment. Nevertheless, another possible strategy is to design on-demand products that can be used in a coitally-dependent manner and only need to be administered immediately before intercourse to offer protection. Vaginal discs based on freeze-dried hydroxypropylmethyl cellulose gels have been developed for this purpose, containing two surfactants, i.e., sodium dodecyl sulphate and polysorbate 60, alone or in combination with 2-hydroxypropyl-β-cyclodextrin, to achieve a formulation capable of incorporating both hydrophilic and lipophilic drugs. Several studies have been carried out to evaluate how the inclusion of these substances modifies the structure of gels (viscosity and consistency studies) and the porosimetry of the freeze-dried discs (scanning electron microscopy micrographs, mechanical properties, swelling behaviour). The drug release and mucoadhesive properties of the discs have also been evaluated with a view to their clinical application. The systems combining sodium dodecyl sulphate and 2-hydroxypropyl-β-cyclodextrin were found to be adequate for the vaginal administration of both Tenofovir and Dapivirine and also offer excellent mucoadhesion to vaginal tissue; these discs could therefore be an interesting option for a coitally-dependent administration to protect women against HIV transmission.

In Vivo Modulation of Cervicovaginal Drug Transporters and Tissue Distribution by Film-Released Tenofovir and Darunavir for Topical Prevention of HIV-1.

Clinical trials have demonstrated partial protection against HIV-1 infection by vaginal microbicide formulations based on antiretroviral (ARV) drugs. Improved formulations that will maintain sustained drug concentrations at viral target sites in the cervicovaginal mucosa are needed. We have previously demonstrated that treatment of cervicovaginal cell lines with ARV drugs can alter gene expression of drug transporters, suggesting that the mucosal disposition of ARV drugs delivered vaginally can be modulated by drug transporters. This study aimed to investigate in vivo modulation of drug transporter expression in a nonhuman primate model by tenofovir and darunavir released from film formulations. Cervicovaginal tissues were collected from drug-naïve macaques and from macaques vaginally treated with film formulations of tenofovir or darunavir. Drug release in vaginal fluid as well as drug absorption in cervicovaginal tissues and lymph nodes were verified by mass spectrometry. The effects of exposure to drugs on the expression of transporters relevant to ARV drugs were evaluated by quantitative PCR. We showed expression in cervicovaginal tissue of drug-naïve macaques of transporters important for distribution of ARV drugs, albeit at lower levels compared to human tissue for key transporters including P-glycoprotein. Concentrations of tenofovir and darunavir well above the EC50 values determined in vitro were detected in vaginal fluid and vaginal tissues of macaques treated with drug-dissolving films over 24 h and were also comparable to those shown previously to modulate drug transporter expression. Accordingly, Multidrug Resistance associated Protein 2 (MRP2) in cervicovaginal tissue was upregulated by both tenofovir and darunavir. The two drugs also differentially induced and/or inhibited expression of key uptake transporters for reverse transcriptase inhibitors and protease inhibitors. The lower expression of key transporters in macaques may result in increased retention of ARV drugs at the simian cervicovaginal mucosa compared to the human mucosa and has implications for translation of preclinical data. Modulation of drug transporter expression by tenofovir and darunavir points to the potential benefit of MRP2 inhibition to increase ARV drug penetration through the cervicovaginal epithelium.

Vaginal progesterone to prevent preterm delivery among HIV-infected pregnant women in Zambia: A feasibility study.

Antenatal vaginal progesterone (VP) reduces the risk of preterm birth (PTB) in women with shortened cervical length, and we hypothesize that it may also prevent PTB in women with HIV as their primary risk factor. We conducted a pilot feasibility study in Lusaka, Zambia to investigate uptake, adherence, and retention in preparation for a future efficacy trial. This was a double-masked, placebo-controlled, randomized trial of 200mg daily self-administered VP suppository or placebo. Pregnant women with HIV who were initiating or continuing antiretroviral therapy were eligible for participation. Potential participants underwent ultrasound to assess eligibility; we excluded those ≥24 gestational weeks, with non-viable, multiple gestation, or extrauterine pregnancies, with short cervix (<2.0cm), or with prior spontaneous PTB. Participants initiated study product between 20–24 weeks of gestation and continued to 37 weeks (or delivery, if sooner). The primary outcome was adherence (proportion achieving ≥80% study product use), assessed by dye stain assay of returned single-use vaginal applicators. Secondary outcomes with pre-defined feasibility targets were: uptake (≥50% eligible participants enrolled) and retention (≥90% ascertainment of delivery outcomes). We also evaluated preliminary efficacy by comparing the risk of spontaneous PTB <37 weeks between groups. From July 2017 to June 2018, 208 HIV-infected pregnant women were eligible for screening and 140 (uptake = 67%) were randomly allocated to VP (n = 70) or placebo (n = 70). Mean adherence was 94% (SD±9.4); 91% (n = 125/137) achieved overall adherence ≥80%. Delivery outcomes were ascertained from 134 (96%) participants. Spontaneous PTB occurred in 10 participants (15%) receiving placebo and 8 (12%) receiving progesterone (RR 0.82; 95%CI:0.34–1.97). Spontaneous PTB < 34 weeks occurred in 6 (9%) receiving placebo and 4 (6%) receiving progesterone (RR 0.67; 95%CI:0.20–2.67). In contrast to findings from vaginal microbicide studies in HIV-uninfected, non-pregnant women, our trial participants were highly adherent to daily self-administered vaginal progesterone. The study’s a priori criteria for uptake, adherence, and retention were met, indicating that a phase III efficacy trial would be feasible.

Trichomonas vaginalis Motility Is Blocked by Drug-Free Thermosensitive Hydrogel.

Trichomonas vaginalis motility in biological fluids plays a prominent, but understudied, role in parasite infectivity. In this study, the ability of a thermosensitive hydrogel (pluronic F127) to physically immobilize T. vaginalis was investigated. Blocking parasite motility could prevent its attachment to the mucosa, thus reducing the acquisition of the infection. The trajectory of individual parasites was monitored by multiple particle tracking. Mean square displacement, diffusivity, and velocity were calculated from x, y coordinates during time. Major results are that T. vaginalis exhibited different types of trajectories in a diluted solution composed of lactate buffer similar to "run-and-tumble" motion reported for flagellated bacteria. The fastest T. vaginalis specimen moves with a velocity of 19 μm/s. Observation of T. vaginalis movements showed that the cell body remains rigid during swimming and that the propulsive forces necessary to generate the movement are the result of flagellar beating. Parasite motility was partially slowed down using hydroxyethylcellulose hydrogel, used as a reference for the development of vaginal microbicides, while 100% of T. vaginalis were immobile in F127 hydrogel. Once completed by biological investigations on mice, this report suggests using drug-free formulation composed of F127 as a new strategy to prevent T. vaginalis attachment to the mucosa. The concept will be extended to other flagellated organisms where the motility is driven by cilia and flagella.

Rational Development of Liposomal Hydrogels: A Strategy for Topical Vaginal Antiretroviral Drug Delivery in the Context of HIV Prevention.

HIV/AIDS stands as a global burden, and vaginal microbicides constitute a promising strategy for topical pre-exposure prophylaxis. Preceding the development of a microbicide containing tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC), in silico and in vitro studies were performed to evaluate the physicochemical characteristics of both drugs, and to study their biophysical impact in lipid model systems. Results from these pre-formulation studies defined hydrogels as adequate vehicles to incorporate TDF-loaded liposomes and FTC. After studying interactions with mucin, zwitterionic liposomes with a mean diameter of 134 ± 13 nm, an encapsulation TDF efficiency of approximately 84%, and a transition temperature of 41 °C were selected. The chosen liposomal formulation was non-cytotoxic to HEC-1-A and CaSki cells, and was able to favor TDF permeation across polysulfone membranes (Jss = 9.9 μg·cm−2·h−1). After the incorporation of TDF-loaded liposomes and FTC in carbomer hydrogels, the drug release profile was sustained over time, reaching around 60% for both drugs within 3–6 h, and best fitting the Weibull model. Moreover, liposomal hydrogels featured pseudoplastic profiles that were deemed suitable for topical application. Overall, the proposed liposomal hydrogels may constitute a promising formulation for the vaginal co-delivery of TDF/FTC.

Acceptability and performance of a nonwoven device for vaginal drug delivery among women and their male partners in KwaZulu-Natal, South Africa

Background: Multipurpose prevention technologies are needed to provide protection against HIV and sexually transmitted infections. Gel-based vaginal microbicides inserted via an applicator are prone to leakage. A novel device for vaginal drug delivery was developed to contain gel-based formulations, aiming to improve gel retention and reduce leakage. The objectives of this study were to assess acceptability and performance of a nonwoven vaginal delivery device.Methods: A nonwoven vaginal delivery device was prepared, pre-saturated with a commercially available water-based lubricant, with a finger pocket for insertion and string for removal. Quantitative and qualitative methods were used to collect data from interviews with 40 women and 10 male partners recruited from a sexual and reproductive health clinic in Durban, KwaZulu-Natal, South Africa. Women wore one device in the clinic and one device overnight or with their partner during intercourse. The primary endpoint was acceptability including comfort, ease of insertion and removal, and opinions on device attributes.Results: Most women said the device was ‘easy’ to insert and remove. Six women reported leakage after insertion and 34 reported having sexual intercourse while wearing the device. One woman was lost-to-follow-up and five women only wore the device overnight because their partners did not agree to intercourse with the inserted device. The best-liked attribute was the device’s lubrication (22 women, 7 men); the least-liked was the removal string (9 women, 8 men).Conclusions: Data are promising for further development of this nonwoven device for vaginal drug delivery.Plain English summaryMultipurpose prevention technologies (MPTs) that protect against HIV and sexually transmitted infections (STIs) are urgently needed. A variety of vaginal gel-based products are actively being researched; however, these products can often have challenges with vaginal leakage and retention. This research investigates the acceptability and performance of a nonwoven device to deliver vaginal gel formulations. The gel used in this study was a currently available marketed personal lubricant. In South Africa, 40 women (and 10 male partners) were recruited and given the opportunity to comment on various device attributes after insertion, overnight wear and sexual intercourse with their male partners. Generally, participants found the device easy to use and acceptable, where many factors possibly contributed to the device’s acceptability (i.e., similarity to tampons, saturation with lubricant, minimal leakage, ease of insertion, comfort during intercourse and the male partners’ willingness to have vaginal intercourse with the device in place). Further studies of the vaginal delivery device for acceptability, safety and efficacy using a gel-based formulation with an active ingredient are warranted.

Impact of a new carrageenan-based vaginal microbicide in a female population with genital HPV-infection: first experimental results.

The objective of this study was to assess safety, satisfaction, and anti-viral effect of a new carrageenan-based vaginal microbicide in a population of fertile female patients with genital human papillomavirus (HPV) infection. Forty healthy and sexually active women aged 18-45 years with genital HPV infection were enrolled. Each subject was treated with a gel formulated with 0.02% carrageenan and Propionibacterium extract (CGP) (Carvir, Depofarma SpA, Mogliano Veneto, Treviso, Italy). The subjects were evaluated at baseline, after the I cycle of therapy and after the II cycle. At final status, treatment acceptability and satisfaction were evaluated using a 5-point Likert scale. Furthermore, the rate of HPV genital infection clearance at final follow-up was evaluated. These data were compared with the HPV genital infection clearance rate in a control group of patients not subjected to any therapy. Overall, 68 HPV infections were detected at baseline, among 40 subjects enrolled. The HPV 16 genotype was the most frequent (12%) followed by HPV 18 (10%), and HPV 53 (9%). At the end of the study, 22 (55%) patients were very satisfied, 14 (35%) were satisfied, 3 (7.5%) were uncertain, and only 1 (2.5%) was dissatisfied, with 0 very dissatisfied. Only 2 patients complained of a local adverse event. Analysing infection clearance at the end of the study, 60% of patients became HPV negative. Among these, 13 cases were high-risk HPV infection. There were 16 patients with persistent infection ("non-responders"). No patient developed a "de novo" genital lesion. After controlling for age, the intervention had an adjusted OR of 4.9 (95% CI 1.6-15.1) to clear HPV. The results of this work suggest that Carvir vulvovaginal microbicide gel is safe and well-tolerated. Furthermore, this experience supports the hypothesis that CG has a role in accelerating the normal clearance of genital HPV infection in women with a positive HPV-DNA test.