Advances in long-acting injectables, implants, and vaginal rings for contraception and HIV prevention

In vitro-in vivo relationship and microstructural insights into long-acting levonorgestrel intrauterine systems

Despite the proven high contraceptive efficacy and safety of levonorgestrel intrauterine systems (LNG-IUSs), no generic versions are currently available in the US market. This is primarily due to the challenges in achieving qualitative and quantitative (Q1/Q2) similarity with the reference listed drug (RLD) stemming from structural and mechanistic complexities, as well as the ultra-long duration of action (up to 8 years) of IUSs. The extremely long-acting release duration makes it difficult to navigate formulation decisions with even a modicum of speed. The burden to demonstrate bioequivalence hinges on awaiting years of release testing. Additionally, variations in microstructural arrangement can affect key formulation characteristics, potentially affecting bioavailability and bioequivalence. To address these challenges, this study presents a comprehensive reverse engineering analysis of commercial LNG-IUSs (Mirena® and Liletta®), including polymer crosslinking and physicochemical and mechanical characterization using FTIR, ssNMR, DSC, TGA, and SEM-EDX. X-ray microscopy (XRM) and focused ion beam-scanning electron microscopy (FIB-SEM) with AI-based analytics were employed to study microstructural changes in unreleased and post in vitro release samples, comparing commercial and in-house IUS variants. Real-time in vitro release testing was conducted for over 7 years for Mirena® and the in-house IUS, and up to 4 years for Liletta®. Additionally, an accelerated release method was developed, enabling full drug release within 100 days. Post-release analysis included assessment of levonorgestrel distribution, particle size, porosity, and structural changes across IUS layers, with findings revealing compositional differences that impact release kinetics. Notably, this study is the first to report an in vitro-in vivo relationship (IVIVR) for ultralong-acting IUSs, correlating in vitro drug release data with in vivo LNG release profiles in humans. The established IVIVR offers a predictive tool for assessing drug release behavior in clinical settings, potentially reducing the clinical burden and accelerating drug development timelines. The current research offers a roadmap for manufacturers to refine their formulation and manufacturing processes to match target attributes. It is anticipated that this research will enhance public access to these highly effective long-acting reversible contraceptives.

Preferences for longer acting pre-exposure prophylaxis in transgender and gender expansive texans: centering gender affirming hormone therapy

The prevalence of HIV is higher in the transgender population than in the general population, and pre-exposure prophylaxis (PrEP) is an effective biomedical HIV prevention strategy for the prevention of HIV. However, the transgender and gender-expansive community faces several challenges to PrEP uptake and adherence. This community-based participatory study was conducted to understand preferences for long-acting PrEP modalities better. Data were collected virtually with an adapted version of the World Café Conversation method and in-depth interviews. A total of 33 transgender and gender-diverse individuals participated in either a World Café conversation or an individual interview about preferences for long-acting PrEP. All qualitative data were transcribed and coded for themes. Two themes emerged: (1) challenges related to long-acting PrEP for transgender and gender-expansive individuals and (2) bundling long-acting PrEP and gender-affirming hormone therapy. To improve access and adherence, HIV prevention needs to be included as part of gender-affirming hormone therapy to align with patients' health priorities.

3D printed reservoir-like vaginal rings for antibiotic delivery

Targeting the development of 3D printed reservoir-like vaginal rings (VRs) intended to fulfill the needs of precision medicine, prototypes ensuring prolonged release of metronidazole (MTZ) were preliminary manufactured and tested. Indeed, this drug represents the first-line therapy against bacterial vaginosis, which would especially benefit from convenient as well as easy dose adjustment and from more than 48 h continuous release, thus avoiding barely tolerated and repeated administrations. Starting from a soft thermoplastic elastomer (TPE), hollow ring structures were successfully printed at 190 °C and then extemporaneously filled with drug-loaded, in-situ-crosslinking hydrogel formulations based on alginate (ALG). 3 VR designs, differing in dimensions, number of open surfaces as well as in relevant areas were investigated, together with 9 drug-saturated hydrogel formulations containing extra suspended MTZ particles (20-50 %) and increasing ALG concentrations (2-6 %). Manufacturing of final rings was fine-tuned based on materials thermo-mechanical properties. For comparison purposes, hydrogels with analogous composition were either cast using purposely developed molds or 3D printed mimicking the ring design. VR release performance turned out dependent on the drug solubility and on the surface area available for hydrogel contact with vaginal fluids. Interestingly, this surface resulted correlated to both the outer and inner structure of the system. The data collected would provide an effective asset to increase the versatility of reservoir-like VRs, making them a powerful tool towards therapy customization.

Rise of implantable drugs: A chronicle of breakthroughs in drug delivery systems

In recent years, implantable drug delivery systems (IDDSs) have undergone significant advancements because they offer many advantages to patients and health care professionals. Miniaturization has reduced the size of these devices, making them less invasive and easier to implant. Remote control provides more precise medication delivery and dosage. Biodegradable implants are an additional advancement in implantable drug delivery systems that eliminate the need for surgical removal. Smart implants can monitor a patient's condition and adjust their drug doses. Long-acting implants also provide sustained drug delivery for months or even years, eliminating the need for regular medication dosing, and wireless power and data transmission technology enables the use of devices that are more comfortable and less invasive. These innovations have enhanced patient outcomes by enabling more precise administration, sustained drug delivery, and improved health care monitoring. With continued research and development, it is anticipated that IDDSs will become more effective and provide patients with improved health outcomes. This review categorizes and discusses the benefits and limitations of recent novel IDDSs for their potential therapeutic use.

3D printing in vaginal drug delivery: a revolution in pharmaceutical manufacturing

INTRODUCTION

The Food and Drug Administration's approval of the first three-dimensional (3D) printed tablet, Spritam®, led to a burgeoning interest in using 3D printing to fabricate numerous drug delivery systems for different routes of administration. The high degree of manufacturing flexibility achieved through 3D printing facilitates the preparation of dosage forms with many actives with complex and tailored release profiles that can address individual patient needs.

AREAS COVERED

This comprehensive review provides an in-depth look into the several 3D printing technologies currently utilized in pharmaceutical research. Additionally, the review delves into vaginal anatomy and physiology, 3D-printed drug delivery systems for vaginal applications, the latest research studies, and the challenges of 3D printing technology and future possibilities.

EXPERT OPINION

3D printing technology can produce drug-delivery devices or implants optimized for vaginal applications, including vaginal rings, intra-vaginal inserts, or biodegradable microdevices loaded with drugs, all custom-tailored to deliver specific medications with controlled release profiles. However, though the potential of 3D printing in vaginal drug delivery is promising, there are still challenges and regulatory hurdles to overcome before these technologies can be widely adopted and approved for clinical use. Extensive research and testing are necessary to ensure safety, effectiveness, and biocompatibility.

Perception of couples' on multipurpose prevention technology attribute choice: the case of MTN 045

BACKGROUND

Multipurpose prevention technologies (MPTs) are products capable of simultaneously addressing multiple sexual and reproductive health needs such as unwanted pregnancy, STIs including HIV-1, and other reproductive tract infections. MPTs are urgently needed to address the double burden of unplanned pregnancy and HIV. While condoms are currently the only accessible MPTs, they are not solely under a woman's control, and female condoms face limitations due to poor acceptability and high cost.

METHODS

We conducted a sub-analysis of qualitative data from 39 couples participating in the MTN 045 study to examine the perception of couples on choice and acceptability of a "2 in 1" MPT that combines HIV and pregnancy prevention.

RESULTS

Couples recognized the benefits of MPTs for HIV and pregnancy prevention but perceptions tied to each indication and a novel prevention technology tool raised important concerns relevant to use of future MPTs. In the study, participants' perceptions of MPT use were influenced by pregnancy planning. When the timing was less critical, they prioritized HIV prevention. Misinformation about family planning methods, including MPTs, affected decision-making with potential to hinder uptake of future MPTs. Concerns about side effects, such as weight gain and hormonal imbalances, influenced willingness to use MPTs.

CONCLUSION

Addressing the myths and misconceptions surrounding the use of contraceptives is crucial in promoting their acceptance and ultimate use. Strategies for addressing the drawbacks women might experience while using a particular product should be in place as new MPTs progress through the development pipeline and approach roll-out.

Long-acting intramuscular injections of ELQ-331, an antimalarial agent

The overarching premise of this investigation is that injectable, long-acting antimalarial medication would encourage adherence to a dosage regimen for populations at risk of contracting the disease. To advance support for this goal, we have developed oil-based formulations of ELQ-331 (a prodrug of ELQ-300) that perform as long-acting, injectable chemoprophylactics with drug loading as high as 160 mg/ml of ELQ-331. In a pharmacokinetic study performed with rats, a single intramuscular injection of 12.14 mg/kg maintained higher plasma levels than the previously established minimum fully protective plasma concentration (33.25 ng/ml) of ELQ-300 for more than 4 weeks. The formulations were well tolerated by the rats and the tested dose produced no adverse reactions. We believe that by extending the length of time between subsequent injections, these injectable oil-based solutions of ELQ-331 can offer a more accessible, low-cost option for long-acting disease prevention and reduced transmission in malaria-endemic regions and may also be of use to travelers.

Sexual and Reproductive Justice and Health Equity for LGBTQ+ Women

LGBTQ+ women have long been overlooked in sexual and reproductive health research. However, recent research has established that LGBTQ+ women have unique and specific needs that need to be addressed in order to improve effectiveness of sexual health education and practice with this historically and presently underserved population. Informed by a reproductive justice framework coupled with liberation psychology theory, this review discusses the current state of sexual and reproductive health and technologies among LGBTQ+ women. In particular, we focus on a range of HIV prevention and reproductive technologies and their use and promotion, including the internal condom, abortion, oral contraceptives, dapivirine ring, HIV pre-exposure prophylaxis, intrauterine device, and other less studied options, such as the contraceptive sponge. Grounded in an intersectional framing, this review acknowledges the intersecting systems of oppression that affect multiply marginalized women inequitably and disproportionately. A sociohistorical, critical lens is applied to acknowledge the well-documented racist origins of reproductive health technologies and ongoing coercive practices that have led to medical mistrust among marginalized and stigmatized communities, particularly racialized LGBTQ+ women, women with disabilities, and women who are poor or incarcerated. Moreover, we discuss the urgent need to center LGBTQ+ women in research and clinical care, community-engaged health promotion efforts, affirming non-heteronormative sexual health education, and health policies that prioritize autonomy and dismantle structural barriers for this population. We conclude with recommendations and future directions in this area to remedy entrenched disparities in health.

Supporting young women's health through girl-friendly drug vendors in Lake Zone, Tanzania: protocol for the AmbassADDOrs for Health cluster-randomised controlled trial

INTRODUCTION

Adverse sexual and reproductive health (SRH) outcomes, such as unplanned pregnancies and HIV infection, disproportionately affect adolescent girls and young women (AGYW; aged 15-24 years) in east Africa. Increasing uptake of preventive SRH services via innovative, youth-centred interventions is imperative to addressing disparities in SRH outcomes.

METHODS AND ANALYSIS

From 2018 to 2019, we used human-centred design to co-develop a theoretically driven HIV and pregnancy prevention intervention for AGYW at private drug shops called Accredited Drug Dispensing Outlets (ADDOs) in Tanzania. The result, Malkia Klabu (Queen Club), was a customer loyalty programme designed to strengthen ADDOs' role as SRH providers while encouraging uptake of critical SRH prevention products among AGYW. Malkia Klabu members had access to free contraceptives and oral HIV self-test (HIVST) kits and earned punches on a loyalty card for other shop purchases; punches were redeemable for small prizes. Our pilot among 40 shops showed that intervention ADDOs had higher AGYW patronage and distributed more HIVST kits and contraceptives to AGYW relative to business-as-usual (ie, client purchasing) comparison shops. We will conduct a cluster-randomised controlled trial (c-RCT) among 120-140 ADDOs in 40 health catchment areas in Shinyanga and Mwanza Regions (Lake Zone), Tanzania. ADDO shop recruitment includes a 1-month run-in with a tablet-based electronic inventory management system for tracking shop transactions, followed by enrolment, randomisation and a 24-month trial period. Our c-RCT evaluating the human-centred design-derived intervention will assess population impact on the primary outcomes of HIV diagnoses and antenatal care registrations, measured with routine health facility data. We will also assess secondary outcomes focusing on mechanisms of action, evaluate programme exposure and AGYW behaviour change in interviews with AGYW, and assess shop-level implementation strategies and fidelity.

ETHICS AND DISSEMINATION

Ethical approval was granted from both the University of California, San Francisco and the Tanzanian National Institute for Medical Research. Study progress and final outcomes will be posted annually to the National Clinical Trials website; study dissemination will occur at conferences, peer-reviewed manuscripts and local convenings of stakeholders.

TRIAL REGISTRATION NUMBER

NCT05357144.

Multitasking Pharmacophores Support Cabotegravir-Based Long-Acting HIV Pre-Exposure Prophylaxis (PrEP)

Cabotegravir is an integrase strand transfer inhibitor (INSTI) for HIV treatment and prevention. Cabotegravir-based long-acting pre-exposure prophylaxis (PrEP) presents an emerging paradigm for infectious disease control. In this scheme, a combination of a high efficacy and low solubility of anti-infection drugs permits the establishment of a pharmaceutical firewall in HIV-vulnerable groups over a long period. Although the structure-activity-relationship (SAR) of cabotegravir as an INSTI is known, the structural determinants of its low solubility have not been identified. In this work, we have integrated multiple experimental and computational methods, namely X-ray diffraction, solid-state NMR (SSNMR) spectroscopy, solution NMR spectroscopy, automated fragmentation (AF)-QM/MM and density functional theory (DFT) calculations, to address this question. The molecular organization of cabotegravir in crystal lattice has been determined. The combination of very-fast magic-angle-sample-spinning (VF MAS) SSNMR and solution NMR, as supported by AF-QM/MM and DFT calculations, permits the identification of structural factors that contribute to the low aqueous solubility of cabotegravir. Our study reveals the multitasking nature of pharmacophores in cabotegravir, which controls the drug solubility and, meanwhile, the biological activity. By unraveling these function-defining molecular features, our work could inspire further development of long-acting HIV PrEP drugs.

Polysaccharide-based hydrogels for medical devices, implants and tissue engineering: A review

Hydrogels are highly biocompatible biomaterials composed of crosslinked three-dimensional networks of hydrophilic polymers. Owing to their natural origin, polysaccharide-based hydrogels (PBHs) possess low toxicity, high biocompatibility and demonstrate in vivo biodegradability, making them great candidates for use in various biomedical devices, implants, and tissue engineering. In addition, many polysaccharides also show additional biological activities such as antimicrobial, anticoagulant, antioxidant, immunomodulatory, hemostatic, and anti-inflammatory, which can provide additional therapeutic benefits. The porous nature of PBHs allows for the immobilization of antibodies, aptamers, enzymes and other molecules on their surface, or within their matrix, potentiating their use in biosensor devices. Specific polysaccharides can be used to produce transparent hydrogels, which have been used widely to fabricate ocular implants. The ability of PBHs to encapsulate drugs and other actives has been utilized for making neural implants and coatings for cardiovascular devices (stents, pacemakers and venous catheters) and urinary catheters. Their high water-absorption capacity has been exploited to make superabsorbent diapers and sanitary napkins. The barrier property and mechanical strength of PBHs has been used to develop gels and films as anti-adhesive formulations for the prevention of post-operative adhesion. Finally, by virtue of their ability to mimic various body tissues, they have been explored as scaffolds and bio-inks for tissue engineering of a wide variety of organs. These applications have been described in detail, in this review.

The Importance of the Individual in PrEP Uptake: Multilevel Correlates of PrEP Uptake Among Adolescent Girls and Young Women in Tshwane, South Africa

Adolescent girls and young women (AGYW) account for 25% of new HIV infections in South Africa. Pre-exposure prophylaxis (PrEP) is approved by the South African Government, but the factors that promote PrEP uptake among AGYW are not well understood. This study examines multilevel factors associated with PrEP uptake among AGYW in six clinic catchment areas in Tshwane (Pretoria), South Africa. After consent/assent, PrEP-eligible AGYW (n = 448) completed a questionnaire assessing factors at the individual, network/interpersonal, and community levels and were prescribed PrEP in study clinics, if interested. A multivariable model, adjusting for clustering, assessed factors associated with PrEP uptake over a 9-month period. At the individual level, multiple partners in the past 3 months (OR = 0.47), perceived risk of HIV (OR = 0.71), and PrEP-related shame (OR = 0.63) were correlated with lower odds of PrEP uptake (ps ≤ 0.05). The findings highlight modifiable factors that should be addressed to support PrEP uptake efforts.

Advances in long-acting slow effective release antiretroviral therapies for treatment and prevention of HIV infection

Adherence to daily oral antiretroviral therapy (ART) is a barrier to both treatment and prevention of human immunodeficiency virus (HIV) infection. To overcome limitations of life-long daily regimen adherence, long-acting (LA) injectable antiretroviral (ARV) drugs, nanoformulations, implants, vaginal rings, microarray patches, and ultra-long-acting (ULA) prodrugs are now available or in development. These medicines enable persons who are or at risk for HIV infection to be treated with simplified ART regimens. First-generation LA cabotegravir, rilpivirine, and lenacapavir injectables and a dapivirine vaginal ring are now in use. However, each remains limited by existing dosing intervals, ease of administration, or difficulties in finding drug partners. ULA ART regimens provide an answer, but to date, such next-generation formulations remain in development. Establishing the niche will require affirmation of extended dosing, improved access, reduced injection volumes, improved pharmacokinetic profiles, selections of combination treatments, and synchronization of healthcare support. Based on such needs, this review highlights recent pharmacological advances and a future treatment perspective. While first-generation LA ARTs are available for HIV care, they remain far from ideal in meeting patient needs. ULA medicines, now in advanced preclinical development, may close gaps toward broader usage and treatment options.

Biomedical, socio-behavioral, and implementation science gaps in multipurpose prevention technology research

There is strong global need for the development of Multipurpose Prevention Technologies (MPTs) that prevent HIV, pregnancy, and/or other sexually transmitted infections (STIs). However, despite decades of research focused on the development of MPTs, numerous research gaps remain, contributing to reproductive health disparities. This commentary will highlight biomedical, socio-behavioral, and implementation science gaps in MPT research. Biomedical gaps and barriers include limited dosage forms, challenges around drug selection and stable coformulation of multiple drugs, and an unclear regulatory pathway. Behavioral, social, and structural gaps include lack of research around MPT preferences for some subgroups of potential end users, lack of knowledge around whether MPTs improve uptake, adherence, and persistence vs. separate products, and a need to further understand how social and cultural factors might impact MPT interest and use. Gaps in implementation science research will need to be addressed to better understand how to implement MPTs to maximize effectiveness and benefit. This commentary will also identify opportunities for integrating biomedical and behavioral science around MPTs.

Solid implantable devices for sustained drug delivery

Implantable drug delivery systems (IDDS) are an attractive alternative to conventional drug administration routes. Oral and injectable drug administration are the most common routes for drug delivery providing peaks of drug concentrations in blood after administration followed by concentration decay after a few hours. Therefore, constant drug administration is required to keep drug levels within the therapeutic window of the drug. Moreover, oral drug delivery presents alternative challenges due to drug degradation within the gastrointestinal tract or first pass metabolism. IDDS can be used to provide sustained drug delivery for prolonged periods of time. The use of this type of systems is especially interesting for the treatment of chronic conditions where patient adherence to conventional treatments can be challenging. These systems are normally used for systemic drug delivery. However, IDDS can be used for localised administration to maximise the amount of drug delivered within the active site while reducing systemic exposure. This review will cover current applications of IDDS focusing on the materials used to prepare this type of systems and the main therapeutic areas of application.

Participant experiences with a multipurpose vaginal ring for HIV and pregnancy prevention during a phase 1 clinical trial: learning from users to improve acceptability

Introduction

With high concurrent global rates of HIV incidence and unintended pregnancy, there is a need to provide options beyond condoms to enable users to simultaneously prevent HIV acquisition and pregnancy. Multiple vaginal rings are in development as "MPTs" (multipurpose prevention technologies) as they are shown to provide several co-occurring benefits such as discretion, convenience, reversibility and user control.

Methods

In this Phase 1 trial of a 3-month MPT ring in the U.S., 25 participants (low-risk for HIV and pregnancy) were randomized to use the study ring for 90 days continuously or in 28-day cycles with 2-day removal periods in between. All participants completed in-depth interviews at the end of their study participation.

Results

Overall, the ring was well tolerated. Participants resoundingly endorsed the concept of an extended-use, dual-purpose vaginal ring, but reported too many functional challenges and side effects to endorse this particular ring. Participants assigned to the continuous regimen reported more positive experiences with ring use than those in the cyclic group. A minority of participants who experienced minimal side effects and did not experience challenges with vaginal retention of the ring found it appealing. However, the majority of participants experienced challenges (ring slippage, expulsions, side effects, vaginal bleeding changes) with product use that outweighed the potential benefits and led them to report that - in the future - they would not be interested in using this specific version of the ring in its current form. A subset expressed interest in using the current MPT ring under certain conditions (e.g., if fewer expulsions, less bleeding, higher risk for HIV/pregnancy).

Discussion

User feedback regarding participant experiences and challenges with the study ring was continuously shared with the product developer, underscoring the value of early-stage end-user feedback in product development.

Strategic actions to advance multipurpose prevention technologies in low- and middle-income countries

Background

HIV, other sexually transmitted infections (STIs) and unintended pregnancies are critical and interlinked health risks for millions of women of reproductive age worldwide. Multipurpose prevention technologies (MPTs) offer an innovative approach for expanding combined pregnancy and/or disease prevention. So far, MPT development efforts have focused mostly on HIV prevention, but about half of product candidates comprise compounds active against non-HIV STIs as well. This review aims to provide a framework that promotes the efficient advancement of the most promising preclinical products through the development pathway and into the hands of end-users, with a focus on women in low- and middle-income countries (L/MICs).

Methods

This mini review provides a summary of the current landscape of the MPT field. It comprises a landscape assessment of MPTs in development, complemented by a series of 28 in-depth, semi-structured key informant interviews (KIIs) with experts representing different L/MIC perspectives.

Main results

We identified six primary action strategies to advance MPTs for L/MICs, including identification of key research gaps and priorities. For each action strategy, progress to date and key recommendations are included.

Conclusions

To realize the life-saving potential of MPTs and maximize the momentum made to date, a strategic, collaborative and well-funded response to the gaps and next steps outlined in this paper is critical. A coordinated response can add rigor and efficiency to the development process, to successfully advance the most promising MPT products to the hands of end-users.

Synthesis of end-user research to inform future multipurpose prevention technologies in sub-Saharan Africa: a scoping review

Introduction

Women in sub-Saharan Africa (SSA) experience disproportionately high rates of HIV infection and unintended pregnancy compared to their age-matched counterparts in other regions of the world. Multipurpose prevention technologies (MPTs) that offer protection against HIV and unintended pregnancy in a single product stand to address these dual sexual and reproductive health needs simultaneously. The aim of this scoping review is to identify factors that are important for optimizing the likelihood of MPT adoption by end users in SSA.

Methods

Study inclusion criteria included MPT research (HIV and pregnancy prevention dual indication) published or presented in English from 2000 to 2022 and conducted in SSA amongst end-users (women aged 15-44), male partners, health care providers, and community stakeholders. References were identified by searching peer reviewed literature, grey literature, conference presentations (2015-2022), grant databases, and outreach to MPT subject matter experts. Of 115 references identified, 37 references met inclusion criteria and were extracted for analysis. A narrative synthesis approach was used to summarize findings within and across MPT products.

Results

Studies were identified from six countries in SSA and a substantial proportion included a South African (n = 27) and/or Kenyan (n = 16) study site. Most studies utilized a qualitative study design (n = 22) and evaluated MPT acceptability and preferences by presenting hypothetical products through images or a list of product attributes (n = 21). The vaginal ring (n = 20), oral tablet (n = 20), and injection (n = 15) were examined most frequently. Across studies, there was high acceptability and demand for an HIV and pregnancy prevention MPT. End users valued choice in prevention product type as well as discreetness and long-acting options. Provider counseling and community sensitization were reported as essential for future introduction of novel MPT delivery forms.

Conclusion

Recognizing the heterogeneity of women's preferences and changing reproductive and sexual health needs over the life course, choice is important in the delivery of pregnancy and HIV prevention products as well as amongst MPT products with distinct product profiles. End user research with active MPTs, vs. hypothetical or placebo MPTs, is necessary to advance understanding of end-user preferences and acceptability of future products.

Long-acting Parenteral Drug Delivery Systems for the Treatment of Chronic Diseases

The management of chronic conditions often requires patients to take daily medication for an extended duration. However, the need for daily dosing can lead to nonadherence to the therapy, which can result in the recurrence of the disease. Long-acting parenteral drug delivery systems have the potential to improve the treatment of chronic conditions. These systems use various technologies, such as oil-based injectables, PLGA-based microspheres, and in situ forming gel-based depots, to deliver different types of drugs. The use of long-acting parenteral formulations for the treatment of chronic infections such as HIV/AIDS and tuberculosis is a recent development in the field. Researchers are also exploring the use of long-acting parenteral formulations for the treatment of malaria, with the aim of reducing dosing frequency and improving adherence to treatment. This review discusses various aspects of long-acting formulation development, including the impact of the physicochemical properties of the drug, the type of long-acting formulation, and the route of administration. The clinical significance of long-acting formulations and recent advances in the field, such as long-acting nanoformulations and long-acting products currently in clinical trials, have also been highlighted.

Electrospun polymer fibers modified with FK506 for the long-term treatment of acute cardiac allograft rejection in a heart transplantation model

FK506, a first-line immunosuppressant, is routinely administered orally and intravenously following heart transplantation. However, frequent administration can result in a substantial psychological burden to patients, resulting in non-adherence to medication. The purpose of our study is to overcome the disadvantages of systemic drug administration by developing a polymer-based delivery system that is tunable and biodegradable and that can release highly hydrophobic FK506 over extended periods to treat or prevent acute cardiac allograft rejection. Using an electrospinning method, long-acting microfibers were prepared, and FK506 appeared to be continuously released for up to 14 days based on the in vitro release profiles. After implanting the microfiber subcutaneously into the abdominals of transplanted rats, it was found that the infiltration of T cells and macrophages and the secretion of interleukin-2 (IL-2) and IL-1β were significantly reduced compared with those of the free FK506 groups. More importantly, the mean survival time (MST) of the PCL-FK506 group was significantly extended in comparison with that of untreated control recipients and free FK506 (MST of untreated control recipients, free FK506, and PCL-FK506 was 8, 26.1, and 37, respectively). In conclusion, we propose that this drug delivery approach would be suitable for developing long-lasting immunomodulatory agents that prolong cardiac graft survival safely and effectively.

Overcoming barriers to patient adherence: the case for developing innovative drug delivery systems

Poor medication adherence is a pervasive issue with considerable health and socioeconomic consequences. Although the underlying reasons are generally understood, traditional intervention strategies rooted in patient-centric education and empowerment have proved to be prohibitively complex and/or ineffective. Formulating a pharmaceutical in a drug delivery system (DDS) is a promising alternative that can directly mitigate many common impediments to adherence, including frequent dosing, adverse effects and a delayed onset of action. Existing DDSs have already positively influenced patient acceptability and improved rates of adherence across various disease and intervention types. The next generation of systems have the potential to instate an even more radical paradigm shift by, for example, permitting oral delivery of biomacromolecules, allowing for autonomous dose regulation and enabling several doses to be mimicked with a single administration. Their success, however, is contingent on their ability to address the problems that have made DDSs unsuccessful in the past.

Co-delivery of an HIV prophylactic and contraceptive using PGSU as a long-acting multipurpose prevention technology

OBJECTIVES

Poly(glycerol sebacate) urethane (PGSU) elastomers formulated with 4'-ethynyl-2-fluoro-2'-deoxyadenosine (EFdA), levonorgestrel (LNG), or a combination thereof can function as multipurpose prevention technology implants for prophylaxis against HIV and unintended pregnancies. For these public health challenges, long-acting drug delivery technologies may improve patient experience and adherence. Traditional polymers encounter challenges delivering multiple drugs with dissimilar physiochemical properties. PGSU offers an alternative option that successfully delivers hydrophilic EFdA alongside hydrophobic LNG.

METHODS

This article presents the formulation, design, and characterization of PGSU implants, highlighting the impact of API loading, dimensions, and individual- versus combination-loading on release rates.

RESULTS

Co-delivery of hydrophilic EFdA alongside hydrophobic LNG acted as a porogen to accelerate LNG release. Increasing the surface area of LNG-only implants increased LNG release. All EFdA-LNG, EFdA-only, and LNG-only formulated implants demonstrated low burst release and linear release kinetics over 245 or 122 days studied to date.

CONCLUSION

PGSU co-delivers two APIs for HIV prevention and contraception at therapeutically relevant concentrations in vitro from a single bioresorbable, elastomeric implant. A new long-acting polymer technology, PGSU demonstrates linear-release kinetics, dual delivery of APIs with disparate physiochemical properties, and biocompatibility through long-term subcutaneous implantation. PGSU can potentially meet the demands of complex MPT or fixed-dose combination products, where better solutions can serve and empower patients.

Overcoming structural barriers to diffusion of HIV pre-exposure prophylaxis

HIV prevention with antiretroviral medication in the form of pre-exposure prophylaxis (PrEP) offers a critical tool to halt the HIV pandemic. Barriers to PrEP access across drug types, formulations, and delivery systems share remarkable commonalities and are likely to be generalizable to future novel PrEP strategies. Appreciation of these barriers allows for planning earlier in the drug-development pathway rather than waiting for the demonstration of efficacy. The purpose of this article is to propose a core set of considerations that should be included in the drug-development process for future PrEP interventions. A literature synthesis of key barriers to PrEP uptake in the United States was conducted to elucidate commonalities across PrEP agents and delivery methods. Based on the published literature, we divided challenges into three main categories of structural barriers: (1) provider and clinic characteristics; (2) cost considerations; and (3) disparities and social constructs, with potential solutions provided for each. Pragmatic strategies for examining and overcoming these barriers before future PrEP regulatory approval are recommended. If these strategies are considered well before the time of commercial availability, the potential for PrEP to interrupt the HIV pandemic will be greatly enhanced.

Prospective acceptability of a multipurpose technology (MPT) implant in preclinical development to prevent HIV and unplanned pregnancy: Qualitative insights from women end users and health care providers in South Africa and Zimbabwe

BACKGROUND

Given the high rates of both HIV and unintended pregnancies in sub-Saharan Africa, the SCHIELD program aims to develop a multipurpose technology implant for HIV and pregnancy prevention. An end-user evaluation was undertaken with young women and health care providers to assess preferences for modifiable implant attributes to improve future adoption and rollout.

METHODS

Focus group discussions were conducted with potential women end users, and health care providers experienced in implant insertion or removal participated in in-depth interviews. All participants were recruited from Harare, Zimbabwe, or Soshanguve, South Africa. The purposively stratified sampled women were either implant experienced or implant naïve and were categorized into three groups: nulliparous, postpartum, or engaged in transactional sex. Topics covered included duration (six months to three years), biodegradability, removability, and independent rod retrievability (per indication). Data were analyzed using Dedoose software and summarized into emerging themes.

RESULTS

Participants identified three key areas that could facilitate rollout, uptake, and adherence of an implant for HIV and pregnancy prevention. First, discreetness was the most salient topic and was associated with implant characteristics such as anatomical location, flexibility, and biodegradability. Second, the ability to independently retrieve the HIV or pregnancy prevention component was preferred, as life circumstances may change and was favored by all participants, except for young women in Soshanguve. Third, there is a need for proper counseling, sensitization, provider training, and health campaigns to facilitate rollout of a 2-in-1 implant.

CONCLUSIONS

A 2-in-1 implant was seen as highly desirable by most young women and health care providers. Participants discussed potential concerns and barriers to uptake of a biodegradable implant with dual HIV prevention and contraceptive properties, identifying key implant attributes that product developers can modify while still in preclinical stages.

Safety and efficacy of a biodegradable implant releasing tenofovir alafenamide for vaginal protection in a macaque model

OBJECTIVES

To advance the initiative of ending the global epidemic, long-lasting HIV protection is needed through sustained release of antiretroviral drugs for months to years. We investigated in macaques the safety and efficacy of biodegradable polycaprolactone implants releasing tenofovir alafenamide for HIV pre-exposure prophylaxis (PrEP).

METHODS

Implants were administered subcutaneously in the arm using a contraceptive trocar. Efficacy against vaginal simian-HIV (SHIV) infection was investigated in six pigtailed macaques that received two tenofovir alafenamide implants (0.35 mg/day), one in each arm, for a total release rate of tenofovir alafenamide at 0.7 mg/day. Macaques were exposed to SHIV twice weekly for 6 weeks. Statistical analyses were used to compare outcome with eight untreated controls. Histological assessments were performed on skin biopsies collected near implantation sites.

RESULTS

Median (range) tenofovir diphosphate level in PBMCs was 1519 (1068-1898) fmol/106 cells. All macaques with tenofovir alafenamide implants were protected against vaginal SHIV infection. In contrast, 7/8 controls were infected after a median of 4 SHIV exposures (P = 0.0047). Histological assessment of tissues near tenofovir alafenamide implant sites showed inflammation and necrosis in 5/6 animals, which were not evident by visual inspection.

CONCLUSIONS

We demonstrated complete protection against vaginal SHIV infection with two implants releasing a total of 0.7 mg of tenofovir alafenamide per day. We also identified tenofovir diphosphate concentrations in PBMCs associated with complete vaginal protection. Consistent with previous findings, we observed adverse local toxicity and necrosis near the tenofovir alafenamide implant site. Improved tenofovir alafenamide implants that are safe and maintain high efficacy have the potential to provide long-lasting protection against vaginal HIV infection.

Long-acting HIV Pre-exposure Prophylaxis (PrEP) approaches: Recent advances, emerging technologies and development challenges

Introduction:

Poor or inconsistent adherence to daily oral pre-exposure prophylaxis (PrEP) has emerged as a key barrier to effective HIV prevention. The advent of potent long-acting (LA) antiretrovirals (ARVs) in conjunction with advances in controlled release technologies has enabled LA ARV drug delivery systems (DDS) capable of providing extended dosing intervals and overcome the challenge of suboptimal drug adherence with daily oral dosing.

Areas covered:

This review discusses the current state of the LA PrEP field, recent advances, and emerging technologies, including ARV prodrug modifications and new DDS. Technological challenges, knowledge gaps, preclinical testing considerations, and future directions important in the context of clinical translation and implementation of LA HIV PrEP are discussed.

Expert opinion:

The HIV prevention field is evolving faster than ever and the bar for developing next-generation LA HIV prevention options continues to rise. The requirements for viable LA PrEP products to be implemented in resource-limited settings are challenging, necessitating proactive consideration and product modifications during the design and testing of promising new candidates. If successfully translated, next-generation LA PrEP that are safe, affordable, highly effective, and accepted by both end-users and key stakeholders will offer significant potential to curb the HIV pandemic.

Smart design of patient centric long-acting products: from preclinical to marketed pipeline trends and opportunities

INTRODUCTION

We see a development in the field of long-acting products to serve patients with chronic diseases by providing benefits in adherence, efficacy and safety of the treatment. This review investigates features of long-acting products on the market/pipeline to understand which drug substance (DS) and drug product (DP) characteristics likely enable a successful patient-centric, low-dosing frequency product.

AREAS COVERED

This review evaluates marketed/pipeline long-acting products with greater than one week release of small molecules and peptides by oral and injectable route of administration (RoA), with particular focus on patient centricity, adherence impact, health outcomes, market trends, and the match of DS/DP technologies which lead to market success.

EXPERT OPINION

Emerging trends are expected to change the field of long-acting products in the upcoming years by increasing capability in engineered molecules (low solubility, long half-life, high potency, etc.), directly developing DP as long-acting oral/injectable, increasing the proportion of products for local drug delivery, and a direction towards more subcutaneous, self-administered products. Among long-acting injectable products, nanosuspensions show a superiority in dose per administration and dosing interval, overwhelming the field of infectious diseases with the recently marketed products.

Couples' Preferences for "2 in 1" Multipurpose Prevention Technologies to Prevent Both HIV and Pregnancy: Results of a Discrete Choice Experiment in Uganda and Zimbabwe

End-user input early in biomedical product development may optimize design to support high uptake and adherence. We interviewed 400 couples (800 total participants) in Uganda and Zimbabwe to assess their preferences for multipurpose prevention technologies (MPTs) for HIV and pregnancy prevention. Using a discrete choice experiment, couples made a series of choices between hypothetical MPTs, including oral tablets and vaginal rings, inserts, and films and completed an interviewer-administered questionnaire assessing sociodemographic and behavioral measures. Most couples preferred presented MPTs over male condoms. Couples’ MPT choices in both countries were influenced most by the combination of product form and dosing frequency, with monthly dosing preferred over daily. Analysis highlighted differences by country as to which side effects were most important: Ugandan couples placed greater importance on effects on the vaginal environment during sex, whereas Zimbabwean couples placed more importance on changes to menstruation and other side effects (headache, cramps). Couples’ preferences signaled an openness to new product forms and more frequent dosing if preferred characteristics of other attributes were achieved.

HIV Pre-exposure Prophylaxis Implant Stated Preferences and Priorities: Results of a Discrete Choice Experiment Among Women and Adolescent Girls in Gauteng Province, South Africa

For adolescent girls (AG) and young women (YW), adherence barriers may limit the effectiveness of daily oral HIV pre-exposure prophylaxis (PrEP). Due to its low-burden and long-lasting product attributes, PrEP implants could remove some of the critical adherence barriers of oral PrEP products for individuals at risk of HIV. To explore stated preferences for a long-acting PrEP implant, we conducted a quantitative survey and discrete choice experiment with AG (ages 15-17), YW (18-34), and female sex workers (FSW; ≥ 18) in Gauteng Province, South Africa. We completed 600 quantitative surveys across the three subgroups of women. Respondents stated preference for an implant that provided longer HIV protection (24 months versus 6 months) and required a single insertion. They stated that they preferred a biodegradable implant that could be removed within 1 month of insertion. Respondents had no preference for a particular insertion location. Overall, 78% of respondents said they would be likely (33%) or very likely (45%) to use a PrEP implant were one available, with the majority (82%) stating preference for a product that would provide dual protection against HIV and unintended pregnancies. To reduce their risk of HIV, AG, YW, and FSW in our survey reported a strong willingness to use long-acting, highly-effective, dissolvable PrEP implants.

PrEP acceptability and initiation among women engaged in sex work in Uganda: Implications for HIV prevention

BACKGROUND

Women engaged in sex work (WESW) are disproportionately affected by HIV. In Uganda, HIV prevalence among WESW is estimated at 37%, accounting for 18% of all new infections in the country. WESW experience poverty, gender-based violence, and other issues that reduce their power and limit their ability to negotiate condom use. Female-controlled strategies, including pre-exposure prophylaxis (PrEP), may afford women more transmission protection, but barriers to access and use persist. This cross-sectional study examined baseline PrEP acceptability and initiation among WESW recently enrolled in a randomized clinical trial in Uganda to test the impact of a combination HIV risk reduction and economic empowerment intervention on sexual risk outcomes (clinicaltrials.gov, NCT03583541).

METHODS

A total of 542 WESW from 19 high HIV-prevalent geographical areas were enrolled in the Kyaterekera study between June 2019 and March 2020. Women were eligible for the study if they: (1) were age 18 or over; (2) reported engagement in transactional sex (a sex act in exchange for pay) in the past 30 days; and (3) reported engagement in one or more episodes of unprotected sex in the past 30 days. Women completed a baseline assessment, were tested for HIV and other sexually transmitted infections (STIs) at enrollment, and were connected with antiretroviral therapy (ART), STI treatment, or PrEP, based on need and interest. Descriptive statistics examined baseline data on PrEP acceptability and initiation. Independent variables (i.e. years in sex work, recent sexual coercion, perceived HIV and sex work stigmas, harmful alcohol use, barriers to medical care, and social support) were derived from the empirical literature and women's self-report. Bivariate analysis was performed to test associations between main effects of these variables. Using binomial logistic regression, predictive models were evaluated for two distinct outcomes-PrEP acceptability and PrEP initiation/uptake.

FINDINGS

At baseline, 59% of women (n = 322) tested HIV negative. Among WESW testing negative, 11% (n = 36) were already PrEP enrolled. Most women reported willingness to use PrEP (n = 317; 91%). Slightly over half of WESW not already on PrEP agreed to initiate PrEP (n = 158; 55%). Logistic regression models demonstrate that acceptability of or willingness to use PrEP was significantly associated with fewer years engaged in sex work (AOR= ·18, 95% CI 0·05-·66, p<·01) and greater perceived social support from family (AOR= 1·39, 95% CI 1·03 -1.88, p<·05). PrEP initiation was negatively associated with greater perceived social support from friends (AOR=·81, 95% CI ·68-0·97, p<·05) and positively associated with higher perceived stigma due to sex work among family members (AOR=2·20, 95% CI 1·15-4·22, p<·05).

INTERPRETATION

Despite endorsing PrEP use, many WESW remain reluctant to use it. This gap in prevention practice highlights the heart of a failing PrEP prevention cascade. Findings point to the important role family and friend support may play in destigmatizing sex work and PrEP use for women. Social and structural-level efforts are needed to improve educational messaging and to integrate positive messaging into health promotion campaigns for women and their families, while also working toward decriminalizing sex work.

FUNDING

This paper was made possible with funding from United States National Institute of Mental Health (Grant number: R01MH116768).

Incorporating HIV Pre-Exposure Prophylaxis Care for Patients Seeking Induced Abortion and Pregnancy Loss Management

BACKGROUND

Family planning clinical encounters are important opportunities for HIV prevention. Our objectives were to 1) estimate the proportion of patients seeking induced abortion and early pregnancy loss management eligible for HIV pre-exposure prophylaxis (PrEP) and 2) compare PrEP eligibility and uptake between patients with unintended and intended pregnancy.

METHODS

We conducted a cross-sectional survey and a nested prospective cohort study of patients seeking an induced abortion or early pregnancy loss management. We assessed pregnancy intendedness, PrEP awareness, HIV risk and risk perception, desire for same-day PrEP start, and PrEP continuation at 30 days. We used the χ² and Fisher's exact tests to assess differences between the participants with intended and unintended pregnancy. We had 80% power to detect a 14% difference in PrEP eligibility between the groups.

RESULTS

We enrolled 250 women. Fifty-six percent (139) had an unintended pregnancy and 44% (110) had an intended pregnancy. PrEP eligibility did not differ significantly between the patients with intended and unintended pregnancy (16% vs. 10%; p = .18). More than one-half (54%, 135/250) were unaware of PrEP before their study visit, and 93% (232/250) considered themselves unlikely to acquire HIV. Of 33 women who were PrEP eligible, 11 accepted same-day start and 1 continued PrEP at 30 days.

CONCLUSIONS

Intendedness of pregnancy was unrelated to PrEP eligibility in women seeking induced abortion and early pregnancy loss management. Most patients seeking these services are unaware of PrEP. Integrating PrEP into family planning care is likely to increase awareness and uptake of PrEP in women.

Dapivirine Vaginal Ring for HIV Prevention in Women in South Africa

Young women remain disproportionately affected by the HIV epidemic in South Africa. Clinical trials have shown that the dapivirine vaginal ring (DVR) is safe and effective at reducing HIV infection in women. In March 2022, the South African Health Products Regulatory Authority approved the use of the DVR in women aged 18 years and older who are unable or unwilling to use oral pre-exposure prophylaxis, as an additional choice for preventing HIV in women at substantial risk. Modelling studies have suggested that the DVR could have a substantial impact if prioritized for women at substantial risk of HIV or women aged 22–29 years. The licensing of the DVR in South Africa is a milestone event that brings the first long-acting and woman-controlled HIV prevention method another step closer to reaching the people who need it. As South Africa prepares its introduction, it is critical to examine the unmet need for HIV prevention and to review the clinical trial data that led to the DVR's approval.

Drug-releasing vaginal rings for HIV/STI and pregnancy prevention: A review of recent advances and clinical applications

INTRODUCTION

Adolescent girls and young women (AGYW), as well as pre- and post-menopausal women globally would benefit from expanded choice to address their sexual and reproductive health (SRH) needs related to Human Immunodeficiency Virus (HIV), sexually transmitted infections (STIs) and pregnancy prevention. Lack of adequate preventative vaccines for HIV/STIs reinforces public health prioritization for options women may use independently to mitigate risk for infectious disease and unplanned pregnancy. Drug releasing intravaginal rings (IVR) represent one such technology that has garnered attention based on the modality's success recently as a pre-exposure prophylaxis (PrEP) delivery option and its impact on reduction in HIV risk.

AREAS COVERED

: This article provides a synopsis of three IVR technologies in active clinical development for prevention of HIV, STI, and unintended pregnancy demonstrating advancements in terms of compatibility with a wide range of drug types with a focus on dapivirine-based silicone rings (International Partnership for Microbicides (IPM), tenofovir-based polyurethane rings (CONRAD), and pod-based rings (Oak Crest Institute of Science).

EXPERT OPINION

The goals of IVR research are to reduce burdens of HIV/STIs and unplanned pregnancies. Through the evolution of IVR technologies, the potential exists to trigger integration of healthcare services through formulation of products with multiple indications.

Long-acting biodegradable implant for sustained delivery of antiretrovirals (ARVs) and hormones

Women worldwide confront two major reproductive health challenges: the need for contraception and protection from sexually transmitted infections, including Human Immunodeficiency Virus (HIV). Multipurpose Prevention Technologies (MPTs) that simultaneously prevent unintended pregnancy and HIV could address these challenges with a single product. Here, we developed a long-acting (LA) subcutaneously administered and biodegradable implant system that provides sustained delivery of contraceptive and antiretroviral (ARV) with zero-order release kinetics. The MPT system involves two implants comprising an extruded tube of a biodegradable polymer, poly(ε-caprolactone) (PCL). Each implant is filled with a formulation of progestin [levonorgestrel (LNG) or etonogestrel (ENG)], or a formulation of a potent ARV [tenofovir alafenamide (TAF), or 4'-Ethynyl-2-fluoro-2'-deoxyadenosine (EFdA)]. We demonstrated sustained in-vitro release of LNG, ENG, and EFdA from the implant system for 13-17 months, while maintaining high stability of the drugs (>99%) within the implant reservoirs. We further elucidated the controlled release mechanism of the implant and leveraged several tunable parameters (e.g., type and quantity of the excipient, PCL properties, and implant wall thickness) to tailor the release kinetics and enhance the mechanical integrity of the MPT implant. The optimized MPT showed sustained in-vitro release of ENG and EFdA over 1 year while maintaining a high level of formulation stability and structural integrity. The MPT implant system was further evaluated in a preclinical study using a rodent model and demonstrated sustained release of EFdA (6 months) and ENG (12 months) with high stability of the drug formulation (>95%). This manuscript supports the continued advancement of LA delivery systems for MPTs.