Drivers of Vaginal Drug Delivery System Acceptability from Internet-Based Conjoint Analysis

Hypotonic, gel-forming delivery system for vaginal drug administration

Vaginal drug delivery is often preferred over systemic delivery to reduce side effects and increase efficacy in treating diseases and conditions of the female reproductive tract (FRT). Current vaginal products have drawbacks, including spontaneous ejection of drug-eluting rings and unpleasant discharge from vaginal creams. Here, we describe the development and characterization of a hypotonic, gel-forming, Pluronic-based delivery system for vaginal drug administration. The rheological properties were characterized with and without common hydrogel polymers to demonstrate the versatility. Both qualitative and quantitative approaches were used to determine the Pluronic F127 concentration below the critical gel concentration (CGC) that was sufficient to achieve gelation when formulated to be hypotonic to the mouse vagina. The hypotonic, gel-forming formulation was found to form a thin, uniform gel layer along the vaginal epithelium in mice, in contrast to the rapidly forming conventional gelling formulation containing polymer above the CGC. When the hypotonic, gel-forming vehicle was formulated in combination with a progesterone nanosuspension (ProGel), equivalent efficacy was observed in the prevention of chemically-induced preterm birth (PTB) compared to commercial Crinone® vaginal cream. Further, ProGel showed marked benefits in reducing unpleasant discharge, reducing product-related toxicity, and improving compatibility with vaginal bacteria in vitro. A hypotonic, gel-forming delivery system may be a viable option for therapeutic delivery to the FRT.

Three-Dimensionally Printed Vaginal Rings: Perceptions of Women and Gynecologists in a Cross-Sectional Survey

Three-dimensional printing technologies can be implemented for the fabrication of personalized vaginal rings (VRs) as an alternative approach to traditional manufacturing. Although several studies have demonstrated the potential of additive manufacturing, there is a lack of knowledge concerning the opinions of patients and clinicians. This study aimed to investigate the perception of women and gynecologists regarding VRs with personalized shapes. The devices were printed with different designs (traditional, "Y", "M", and flat circle) by Fused Deposition Modeling for a cross-sectional survey with 155 participants. Their anticipated opinion was assessed through a questionnaire after a visual/tactile analysis of the VRs. The findings revealed that most women would feel comfortable using some of the 3D-printed VR designs and demonstrated good acceptability for the traditional and two innovative designs. However, women presented multiple preferences when the actual geometry was assessed, which directly related to their age, previous use of the vaginal route, and perception of comfort. In turn, gynecologists favored prescribing traditional and flat circle designs. Overall, although there was a difference in the perception between women and gynecologists, they had a positive opinion of the 3D-printed VRs. Finally, the personalized VRs could lead to an increase in therapeutic adherence, by meeting women's preferences.

Use of Stated Preference Methods in HIV Treatment and Prevention Research in the United States: A Systematic Review

Stated preference (SP) methods are increasingly being applied to HIV-related research and continuously provide researchers with health utility scores of select healthcare products or services that populations consider important. Following PRISMA guidelines, we sought to understand how SP methods have been applied in HIV-related research. We conducted a systematic review to identify studies meeting the following criteria: SP method is clearly stated, conducted in the United States, was published between 01/01/2012 and 02/12/2022, and included adults aged 18 and over. Study design and SP method application were also examined. We identified six SP methods (e.g., Conjoint Analysis, Discrete Choice Experiment) across 18 studies, which were categorized into one of two groups: HIV prevention and HIV treatment-care. Categories of attributes used in SP methods largely focused on: administration, physical/health effects, financial, location, access, and external influences. SP methods are innovative tools capable of informing researchers on what populations consider most beneficial when deciding on treatment, care, or prevention options for HIV.

3D Printing of Paracetamol Suppositories: An Automated Manufacturing Technique for Individualized Therapy

Pharmaceutical compounding using the molding technique is the currently applied method for the on-demand manufacturing of suppositories and pessaries. Potential errors of this method are difficult to detect, and the possibilities of individualization of size and shape of the suppositories are limited. In this study, a syringe-based semi-solid 3D printing technique was developed for the manufacturing of suppositories in three different printing designs with the suppository bases polyethylene glycol (PEG) and hard fat (HF). The 3D printed suppositories were analyzed for their visual appearance, uniformity of mass and content, diametrical dimension, breaking force and release behavior and compared to suppositories of the same composition prepared by a commonly used molding technique. The results showed no adverse properties for the 3D printed suppositories compared to the molded ones. Moreover, the easy adaptation of shape using the 3D printing technique was demonstrated by the printing of different sizes and infill structures. Thus, 3D printing has great potential to complement the available manufacturing methods for compounded suppositories, as it represents an automated system for the individualized manufacturing of suppositories that meet patients' needs.

Women-specific routes of administration for drugs: A critical overview

The woman's body presents a number of unique anatomical features that can constitute valuable routes for the administration of drugs, either for local or systemic action. These are associated with genitalia (vaginal, endocervical, intrauterine, intrafallopian and intraovarian routes), changes occurring during pregnancy (extra-amniotic, intra-amniotic and intraplacental routes) and the female breast (breast intraductal route). While the vaginal administration of drug products is common, other routes have limited clinical application and are fairly unknown even for scientists involved in drug delivery science. Understanding the possibilities and limitations of women-specific routes is of key importance for the development of new preventative, diagnostic and therapeutic strategies that will ultimately contribute to the advancement of women's health. This article provides an overview on women-specific routes for the administration of drugs, focusing on aspects such as biological features pertaining to drug delivery, relevance in current clinical practice, available drug dosage forms/delivery systems and administration techniques, as well as recent trends in the field.

Design aspects of vaginal applicators that influence acceptance among target users

Although sensory-guided product design is most traditionally used by food and beverage companies, the approach has widespread application for many other products, including pharmaceuticals and medical devices. Previously, our team used sensory methods to explore preclinical optimization of soft-gel vaginal microbicides. Past clinical trials suggest vaginal microbicides may be an effective means for women to protect themselves from HIV and other sexually transmitted infections, but these microbicides will not work if they are not used due to poor acceptability. Our prior work suggests properties like firmness, size, and shape all influence women's willingness to try soft-gel vaginal suppositories. As product insertion is part of the overall experience of using vaginal microbicides, understanding the features of vaginal applicators that appeal to women, and incorporating these insights into vaginal drug delivery systems, may also improve user adherence. Despite widespread use of vaginal applicators, there is minimal public data on women's perceptions of and preferences for physical applicator features. Other work suggests women want vaginal applicators that are single use, pre-filled, made of plastic, and easy to use, store, and discard. Applicator attributes that may be important to women, such as length, color, or visual appeal, have not been investigated previously. The objective of this research was to understand what physical applicator attributes are appealing to women. Here, 18 commercially available applicators were evaluated by a convenience sample of women (n = 102) for overall liking and perceptions of various attributes (perceived length and width, ease-of-grip, expected ease-of-use, expected comfort inside the body, visual appeal, color liking, and environmental friendliness). Preference mapping using both liking data and attribute data showed attributes such as color, visual appeal, ease of grip, expected ease of use, and expected comfort inside the body drove higher liking ratings for applicators, while perceived length negatively affected liking. In general, plastic tampon applicators contained more positive features and were better liked relative to a cardboard tampon applicator or applicators for insertion of medicated gels or suppositories. Incorporating more desirable features into applicators meant for insertion of vaginal microbicides or other vaginal medications may improve the user experience, and possibly user adherence.

Eliciting Preferences for HIV Prevention Technologies: A Systematic Review

Background

Many human immunodeficiency virus (HIV) prevention technologies (pre-exposure prophylaxis, microbicides, vaccines) are available or in development. Preference elicitation methods provide insight into client preferences that may be used to optimize products and services. Given increased utilization of such methods in HIV prevention, this article identifies and reviews these methods and synthesizes their application to HIV prevention technologies.

Methods

In May 2020, we systematically searched peer-reviewed literature in PubMed, CINAHL, and Web of Science for studies employing quantitative preference elicitation methods to measure preferences for HIV prevention technologies among populations of any age, sex, or location. Quality assessment used an existing checklist (PREFS) and a novel adaptation of the Newcastle–Ottawa Scale (PROSPERO #CRD42018087027).

Results

We screened 5022 titles and abstracts, reviewed 318 full texts, and included 84 studies. Common methods employed were discrete-choice experiment (33%), conjoint analysis (25%), and willingness-to-participate/try/accept (21%). Studies were conducted in 25 countries and had a mean of 768 participants (range = 26–7176), two-thirds of them male. Common HIV prevention technologies included pre-exposure prophylaxis (23%), voluntary testing and counseling (19%), HIV self-testing (17%), vaccines (15%), and topical microbicides (9%). Most attributes focused on product design (side effects, frequency), service design (provider type, location), acceptability or willingness to accept/pay; results are summarized in these categories, by prevention type. Mean quality-adapted Newcastle–Ottawa Scale score was 4.5/8 (standard deviation = 2.1) and mean PREFS scores was 3.47/5 (standard deviation = 0.81).

Conclusions

This review synthesizes extant literature on quantitative measurement of preferences for HIV prevention technologies. This can enable practitioners to improve prevention products and interventions, and ultimately reduce HIV incidence.

Lubrication and Vaginal Sex: Lubricant Use and Preferences in General Population Women and Women at Risk of HIV

Personal or additional lubricants are used by individuals to enhance sexual experience. Lubrication norms during sex are linked to factors including sociocultural norms, gender dynamics, age, and education. This article provides an overview of literature, exploring thematic areas of interest and relevance to the topic. In some regions/countries, lubricated sex is preferable, and in others, a dry/tight vagina is preferred. Women may use a variety of products to achieve these states. There is little research on lubrication preferences during sex; however, microbicide gel acceptability and adherence studies have provided some insight into these preferences. There is a need for more information on lubrication preferences, including volumes, frequency of use, and site of application. In addition, condom use with lubricants needs further exploration. Context, gender, and individual preferences have implications for acceptability and use of personal additional lubricants and should be taken into account during marketing and dissemination of these products.

Stated-preference research in HIV: A scoping review

Discrete choice experiments (DCE), conjoint analysis (CA), and best-worst scaling (BWS) are quantitative techniques for estimating consumer preferences for products or services. These methods are increasingly used in healthcare research, but their applications within the field of HIV research have not yet been described. The objective of this scoping review was to systematically map the extent and nature of published DCE, CA, and BWS studies in the field of HIV and identify priority areas where these methods can be used in the future. Online databases were searched to identify published HIV-related DCE, CA and BWS studies in any country and year as the primary outcome. After screening 1,496 citations, 57 studies were identified that were conducted in 26 countries from 2000-2017. The frequency of published studies increased over time and covered HIV themes relating to prevention (n = 25), counselling and testing (n = 10), service delivery (n = 10), and antiretroviral therapy (n = 12). Most studies were DCEs (63%) followed by CA (37%) and BWS (4%). The median [IQR] sample size was 288 [138-496] participants, and 74% of studies used primary qualitative data to develop attributes. Only 30% of studies were conducted in sub-Saharan Africa where the burden of HIV is highest. Moreover, few studies surveyed key populations including men who have sex with men, transgender people, pregnant and postpartum women, adolescents, and people who inject drugs. These populations represent priorities for future stated-preference research. This scoping review can help researchers, policy makers, program implementers, and health economists to better understand the various applications of stated-preference research methods in the field of HIV.

Development of a mucoinert progesterone nanosuspension for safer and more effective prevention of preterm birth

Preterm birth (PTB) is a significant global problem, but few therapeutic options exist. Vaginal progesterone supplementation has been demonstrated to reduce PTB rates in women with a sonographic short cervix, yet there has been little investigation into the most effective dose or delivery form. Further, vaginal products like progesterone gel often contain excipients that cause local toxicity, irritation, and leakage. Here, we describe the development and characterization of a mucoinert vaginal progesterone nanosuspension formulation for improved drug delivery to the female reproductive tract. We compare the pharmacokinetics and pharmacodynamics to the clinical comparator progesterone gel in pregnant mice and demonstrate increased vaginal absorption and biodistribution via the uterine first-pass effect. Importantly, the unique plasma progesterone double peak observed in humans, reflecting recirculation from the uterus, was also observed in pregnant mice with vaginal dosing. We adapted a mouse model of progesterone withdrawal that was previously believed to be incompatible with testing the efficacy of exogenous progestins, and are first to demonstrate efficacy in preventing preterm birth with vaginal progesterone in this model. Further, improved vaginal progesterone delivery by the nanosuspension led to increased efficacy in PTB prevention. Additionally, we identified histological and transcriptional evidence of cervical and uterine toxicity with a single vaginal administration of the clinical gel that are absent after dosing with the mucoinert nanosuspension formulation. We demonstrate that a progesterone formulation that is designed for improved vaginal progesterone absorption and vaginal biocompatibility could be more effective for PTB prevention.

Qualitative exploration of intrinsic and extrinsic factors that influence acceptability of semisoft vaginal suppositories

BACKGROUND

Vaginal microbicides are a promising means to prevent the transmission of HIV and other sexually transmitted infections, by empowering women to initiate use prophylactically when they perceive themselves to be at risk. However, in clinical trials, microbicides have shown mixed results, with the consistent finding that effectiveness varies substantially as a function of user adherence.

METHODS

Based on the assumption that adherence is driven, at least in part, by product properties that influence acceptability, we used softgel technology to develop vaginal drug delivery systems in the intermediate texture space between solids and liquids to overcome potential shortcomings of current dosage forms. Here, we used focus groups and surveys to determine women's initial reactions (i.e., acceptance and willingness-to-try) for semisoft vaginal suppositories intended for HIV and STI prevention, with a specific focus on how perception of and preferences for vaginal suppositories may be influenced by product characteristics such as size, shape, and firmness.

RESULTS

Via focus groups, we identified intrinsic and extrinsic factors relevant to acceptability of semisoft suppository prototypes. Willingness-to-try depended on factors like intended functionality, anticipated leakage, type of sex, recommended frequency of use, type of sexual partner, and perceived risk. When handled ex vivo, shape, size, and firmness of suppositories communicated information about ease of imagined insertion and handling, perceived effectiveness, anticipated awareness and comfort of the product in the body. These impressions were partly based on prior experience with vaginal products.

CONCLUSIONS

Sensory attributes appear to play a substantial role in women's preferences and willingness to try the semisoft suppositories. Using these methods during preclinical development should help efficiently optimize a final product that is both biologically efficacious and preferred by women, toward a goal of enhancing adherence and effectiveness.

Self-reported Smoking Status, TAS2R38 Variants, and Propylthiouracil Phenotype: An Exploratory Crowdsourced Cohort Study

TAS2R38 gene variants, which confer sensitivity to specific bitter tastants (e.g., 6-n-propylthiouracil), have been repeatedly associated with lower alcohol use via greater bitterness perception, but research exploring TAS2R38 variation in relation to smoking shows mixed results. In both, the working hypothesis is that 1 or more copies of the functional allele increases bitterness and may provide a barrier to early use. Such a barrier to initiation may, conceivably, manifest as differential rates of current use across diplotypes. Here, an age-diverse convenience sample (n = 886) of Denver Museum of Nature and Science guests was used to explore cross-sectional relationships between TAS2R38 diplotype, self-reported tobacco use (current, former, never smokers), and a rapid measure of 6-n-propylthiouracil phenotype (bitterness of filter paper discs). TAS2R38 diplotypes were determined by Sanger sequencing. After excluding rare diplotypes, data from 814 participants were analyzed. A mix of current (~10%), former (25%), and never smokers (65%) were included. As expected, there was a relationship between TAS2R38 diplotype and 6-n-propylthiouracil bitterness. However, contrary to our hypothesis, there was no evidence of a relationship between diplotype and smoker status among participants with common TAS2R38 diplotypes. Notably, we observed a relationship between of 6-n-propylthiouracil bitterness and smoking status, but the effect was opposite of what was expected: current smokers perceived higher (not lower) bitterness than never smokers. When all the various factors (diplotype, age, sex, and smoking status) were included in ANOVA, all remained predictive of 6-n-propylthiouracil bitterness. Reasons for greater phenotypic bitterness among current smokers are unknown and merit further study.

On-demand microbicide products: design matters

Sexual intercourse (vaginal and anal) is the predominant mode of human immunodeficiency virus (HIV) transmission. Topical microbicides used in an on-demand format (i.e., immediately before or after sex) can be part of an effective tool kit utilized to prevent sexual transmission of HIV. The effectiveness of prevention products is positively correlated with adherence, which is likely to depend on user acceptability of the product. The development of an efficacious and acceptable product is therefore paramount for the success of an on-demand product. Acceptability of on-demand products (e.g., gels, films, and tablets) and their attributes is influenced by a multitude of user-specific factors that span behavioral, lifestyle, socio-economic, and cultural aspects. In addition, physicochemical properties of the drug, anatomical and physiological aspects of anorectal and vaginal compartments, issues relating to large-scale production, and cost can impact product development. These factors together with user preferences determine the design space of an effective, acceptable, and feasible on-demand product. In this review, we summarize the interacting factors that together determine product choice and its target product profile.

Progress and Perspectives on HIV-1 microbicide development

The majority of HIV-1 infections occur via sexual intercourse. Women are the most affected by the epidemic, particularly in developing countries, due to their socio-economic dependence on men and the fact that they are often victims of gender based sexual violence. Despite significant efforts that resulted in the reduction of infection rates in some countries, there is still need for effective prevention methods against the virus. One of these methods for preventing sexual transmission in women is the use of microbicides. In this review we provide a summary of the progress made toward the discovery of affordable and effective HIV-1 microbicides and suggest future directions. We show that there is a wide range of compounds that have been proposed as potential microbicides. Although most of them have so far failed to show protection in humans, there are many promising ones currently in pre-clinical studies and in clinical trials.