The first uterine pass effect

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.

Oestrogens in oral contraception: considerations for tailoring prescription to women's needs

BACKGROUND

The oestrogenic component of combined oral contraceptives (COCs) has changed over years with the aim of reducing oestrogen-related side effects and risks, whilst maintaining oestrogen beneficial effects, particularly on cycle control.

PURPOSE

To describe the pharmacological profiles of different oestrogens commonly used in COCs to provide insights on contraceptive prescription tailored to women's needs.

RESULTS

All COCs ensure a high contraceptive efficacy. COCs containing the natural oestrogens oestradiol (E2), oestradiol valerate (E2V) and estetrol (E4) have limited impact on liver metabolism, lipid and carbohydrate metabolism, haemostasis and sex hormone binding globulin levels, compared with ethinylestradiol (EE). COCs with E2 and E2V appear also to entail a lower elevation of the risk of venous thromboembolism vs. EE-containing pills. No epidemiological data are available for E4-COC. E2- and E2V-containing COCs seem to exert a less stabilising oestrogenic effect on the endometrium compared with EE-COCs. The E4-COC results in a predictable bleeding pattern with a high rate of scheduled bleeding and minimal unscheduled bleeding per cycle. Based on in vitro and in vivo animal data, E4 seems to be associated with a lower effect on cell breast proliferation.

CONCLUSION

Today various COCs contain different oestrogens. Prescribers must be familiar with the different properties of each oestrogen for a tailored contraceptive recommendation, considering their safety and contraceptive efficacy, as well as women's needs and preferences.

Vaginal drug delivery system: A promising route of drug administration for local and systemic diseases

Scientists around the globe have done cutting-edge research to facilitate the delivery of poorly absorbed drugs via various routes of administration and different delivery systems. The vaginal route of administration has emerged as a promising mode of drug delivery, attributed to its anatomy and physiology. Novel drug delivery systems overcome the demerits of conventional systems via nanobiotechnology. This review will focus on the disorders associated with women that are currently targeted by vaginal drug delivery systems. In addition, it will provide insights into innovations in drug formulations for the general benefit of women.

Nanomaterials Solutions for Contraception: Concerns, Advances, and Prospects

Preventing unintentional pregnancy is one of the goals of a global public health policy to minimize effects on individuals, families, and society. Various contraceptive formulations with high effectiveness and acceptance, including intrauterine devices, hormonal patches for females, and condoms and vasectomy for males, have been developed and adopted over the last decades. However, distinct breakthroughs of contraceptive techniques have not yet been achieved, while the associated long-term adverse effects are insurmountable, such as endocrine system disorder along with hormone administration, invasive ligation, and slowly restored fertility after removal of intrauterine devices. Spurred by developments of nanomaterials and bionanotechnologies, advanced contraceptives could be fulfilled via nanomaterial solutions with much safer and more controllable and effective approaches to meet various and specific needs for women and men at different reproductive stages. Nanomedicine techniques have been extended to develop contraceptive methods, such as the targeted drug delivery and controlled release of hormone using nanocarriers for females and physical stimulation assisted vasectomy using functional nanomaterials via photothermal treatment or magnetic hyperthermia for males. Nanomaterial solutions for advanced contraceptives offer significantly improved biosafety, noninvasive administration, and controllable reversibility. This review summarizes the nanomaterial solutions to female and male contraceptives including the working mechanisms, clinical concerns, and their merits and demerits. This work also reviewed the nanomaterials that have been adopted in contraceptive applications. In addition, we further discuss safety considerations and future perspectives of nanomaterials in nanostrategy development for next-generation contraceptives. We expect that nanomaterials would potentially replace conventional materials for contraception in the near future.

What now? A critical evaluation of over 20 years of clinical and research experience with 17-alpha hydroxyprogesterone caproate for recurrent preterm birth prevention

Spontaneous preterm birth is multifactorial, and underlying etiologies remain incompletely understood. Supplementation with progestogens, including 17-alpha hydroxyprogesterone caproate has been a mainstay of prematurity prevention strategies in the United States in the last 2 decades. Following a recent negative confirmatory trial, 17-alpha hydroxyprogesterone caproate was withdrawn from the US market and is currently available only through clinical research studies. This expert review summarized clinical and research data regarding the use of 17-alpha hydroxyprogesterone caproate in the United States from 2003 to 2023 for recurrent prematurity prevention. In 17-alpha hydroxyprogesterone caproate. The history of the use, mechanisms of action, clinical trial results, and efficacy by clinical and biologic criteria of 17-alpha hydroxyprogesterone caproate are presented. We report that disparate findings and conclusions between similarly designed rigorous studies may reflect differences in a priori risk and population incidence and extreme care should be taken in interpreting the studies and making decisions regarding efficacy of 17-alpha hydroxyprogesterone caproate for the prevention of preterm birth. The likelihood of improved obstetrical outcomes after receiving 17-alpha hydroxyprogesterone caproate may vary by clinical factors (eg, body mass index), plasma drug concentrations, and genetic factors, although the identification of individuals most likely to benefit remains imperfect. It is crucial for the medical community to recognize the importance of preserving the decades-long efforts invested in preventing recurrent preterm birth in the United States. Moreover, it is important that we thoroughly and thoughtfully evaluate 17-alpha hydroxyprogesterone caproate as a promising contender for future well-executed prematurity studies.

Development, characterization and evidence of anti-endometriotic activity of Phytocannabinoid-Rich nanoemulsions

During the last decades, the cannabinoid research for therapeutic purposes has been rapidly advancing, with an ever-growing body of evidence of beneficial effects for a wide sort of conditions, including those related to mucosal and epithelial homeostasis, inflammatory processes, immune responses, nociception, and modulating cell differentiation. β-caryophyllene (BCP) is a lipophilic volatile sesquiterpene, known as non-cannabis-derived phytocannabinoid, with documented anti-inflammatory, anti-proliferative and analgesic effects in both in vitro and in vivo models. Copaiba oil (COPA) is an oil-resin, mainly composed of BCP and other lipophilic and volatile components. COPA is reported to show several therapeutic effects, including anti-endometriotic properties and its use is widespread throughout the Amazonian folk medicine. COPA was nanoencapsulated into nanoemulsions (NE), then evaluated regarding the potential for transvaginal drug delivery and providing endometrial stromal cell proliferation in vitro. Transmission electron microscopy (TEM) showed that spherical NE were obtained with COPA concentration that varied from 5 to 7 wt%, while surfactant was maintained at 7.75 wt%. Dynamic light scattering (DLS) measurements showed droplet sizes of 30.03 ± 1.18, 35.47 ± 2.02, 43.98 ± 4.23 and PdI of 0.189, 0.175 and 0.182, respectively, with stability against coalescence and Ostwald ripening during 90 days. Physicochemical characterization results suggest that NE were able to both improve solubility and loading capacity, and increase thermal stability of COPA volatile components. Moreover, they showed slow and sustained release for up to eight hours, following the Higuchi kinetic model. Endometrial stromal cells from non-endometriotic lesions and ectopic endometrium were treated with different concentrations of COPA-loaded NE for 48 h to evaluate its effect on cell viability and morphology. The results suggested significant decrease in cell viability and morphological modifications in concentrations higher than 150 μg/ml of COPA-loaded NE, but not when cells were treated with the vehicle (without COPA). Given the relevance of Copaifera spp. species in folk medicine and their bio economical importance in the Amazon, the development of novel formulations to overcome the technological limitations related to BCP and COPA, is promising. Our results showed that COPA-loaded NE can lead to a novel, uterus-targeting, more effective and promising natural alternative treatment of endometriosis.

Comparing the efficacy of vaginal micronized progesterone gel and capsule for prevention of preterm birth in singleton pregnancies with short cervical length at midtrimester: an indirect comparison meta-analysis

Objective: To evaluate the effectiveness of vaginal progesterone in preventing preterm birth in women with a singleton gestation and short cervical length and to determine which of the two formulations, micronized progesterone vaginal capsule versus vaginal gel containing micronized progesterone, is more effective for preventing preterm birth. Data sources: A systematic search was performed in the following databases: EMBASE, PubMed (MEDLINE), The Cochrane Library, and the Clinical Trials Registry (clinicaltrials.gov). Study eligibility criteria: Randomized controlled trials (RCTs), prospective and retrospective observational studies were included. We searched for progesterone administration to prevent preterm birth in asymptomatic women with a shortened cervix (<25 mm) measured by ultrasound in the second trimester of singleton pregnancy. Study appraisal and synthesis methods: Assessments of the risk of bias of RCTs were performed by applying the Cochrane Collaboration's Risk of Bias Tool; non-randomized control trials were evaluated with the Newcastle-Ottawa Scale (NOS). The primary outcome was preterm birth ≤33 weeks of gestation. Pooled relative risks (RR) and 95% CI's were calculated for dichotomous outcomes. Heterogeneity of treatment effect was assessed with the I² statistic. We pooled results of the primary outcome for individual studies using a random-effect model. We then performed a network meta-analysis to pool indirect comparisons between the two formulations (gel vs capsule). This analysis was performed using the network meta-analysis package within the R environment. Results: Five studies met the inclusion criteria (4 RCTs, one cohort study) including 1,048 women. The meta-analysis demonstrated that vaginal micronized progesterone significantly reduces preterm birth risk, Risk Ratio = 0.63; 95% CI, 0.48-0.82; p = 0.0006; with no heterogeneity between the studies: I ² = 0%. In the network meta-analysis, no significant difference was demonstrated (OR = 0.85; 95% CI, 0.43-1.69) between the effect of the two formulations of vaginal micronized progesterone (vaginal gel versus vaginal capsules) on the risk of PTB. Conclusion: Vaginal progesterone is associated with a decreased risk of premature birth in women with a shortened cervix in the second trimester of pregnancy. No differences were found between vaginal micronized progesterone in gel or capsule formulations. Systematic Review Registration: PROSPERO, identifier CRD42020165198.

Cervicovaginal mucus barrier properties during pregnancy are impacted by the vaginal microbiome

Introduction

Mucus in the female reproductive tract acts as a barrier that traps and eliminates pathogens and foreign particles via steric and adhesive interactions. During pregnancy, mucus protects the uterine environment from ascension of pathogens and bacteria from the vagina into the uterus, a potential contributor to intrauterine inflammation and preterm birth. As recent work has demonstrated the benefit of vaginal drug delivery in treating women's health indications, we sought to define the barrier properties of human cervicovaginal mucus (CVM) during pregnancy to inform the design of vaginally delivered therapeutics during pregnancy.

Methods

CVM samples were self-collected by pregnant participants over the course of pregnancy, and barrier properties were quantified using multiple particle tracking. 16S rRNA gene sequencing was performed to analyze the composition of the vaginal microbiome.

Results

Participant demographics differed between term delivery and preterm delivery cohorts, with Black or African American participants being significantly more likely to delivery prematurely. We observed that vaginal microbiota is most predictive of CVM barrier properties and of timing of parturition. Lactobacillus crispatus dominated CVM samples showed increased barrier properties compared to polymicrobial CVM samples.

Discussion

This work informs our understanding of how infections occur during pregnancy, and directs the engineering of targeted drug treatments for indications during pregnancy.

Effectiveness of progesterone supplementation in women presenting low progesterone levels on the day of frozen embryo transfer: a randomised controlled trial

INTRODUCTION

Progesterone is an essential hormone involved in the process of implantation and pregnancy maintenance. Evidence from recent studies has supported the importance of serum progesterone level around the time of embryo transfer in hormonal replacement therapy frozen embryo transfer cycles and recommended the need for individualised luteal support. Low progesterone around the time of embryo transfer is found to be associated with decreased rate of pregnancy after frozen embryo transfer. This single-centre, longitudinal, randomised, interventional controlled study aims to compare the rate of ongoing pregnancy between two groups of women with progesterone level below 10 ng/mL on the day of frozen embryo transfer: the study group using 800 mg vaginal micronised progesterone supplemented with 50 mg intramuscular progesterone per day and the control group using only 800 mg vaginal micronised progesterone.

METHODS AND ANALYSIS

We enrol patients who are undergoing frozen embryo transfers with blastocyst-stage or cleavage-stage embryos and who satisfy the inclusion and exclusion criteria. After signing the informed consent, participants are randomised into two groups: the study group using vaginal micronised progesterone supplemented with progesterone intramuscular 50 mg per day and the control group using only vaginal micronised progesterone. Randomisation will be performed using R software at a 1:1 allocation ratio. Sequentially numbered, opaque sealed envelopes are used for allocation. The primary outcome is the rate of ongoing pregnancy. To demonstrate a difference of 10% with regard to rate of ongoing pregnancy, at least 370 participants per arm are required (type I error α=0.05, power=0.8). Assuming a dropout rate of 10%, a total of 824 patients (412 per group) will be invited.

ETHICS AND DISSEMINATION

This study was approved by the Ethics Committee of Tu Du Hospital on 17 May 2021 (reference number: 1251/QĐ-BVTD). All participants provide informed consent before being enrolled in the study. The results of our study will be submitted to reproductive medicine conferences and journals.

TRIAL REGISTRATION NUMBER

NCT04897269.

Low Luteal Serum Progesterone Levels Are Associated With Lower Ongoing Pregnancy and Live Birth Rates in ART: Systematic Review and Meta-Analyses

Progesterone plays a key role in implantation. Several studies reported that lower luteal progesterone levels might be related to decreased chances of pregnancy. This systematic review was conducted using appropriate key words, on MEDLINE, EMBASE, and the Cochrane Library, from 1990 up to March 2021 to assess if luteal serum progesterone levels are associated with ongoing pregnancy (OP) and live birth (LB) rates (primary outcomes) and miscarriage rate (secondary outcome), according to the number of corpora lutea (CLs). Overall 2,632 non-duplicate records were identified, of which 32 relevant studies were available for quantitative analysis. In artificial cycles with no CL, OP and LB rates were significantly decreased when the luteal progesterone level falls below a certain threshold (risk ratio [RR] 0.72; 95% confidence interval [CI] 0.62-0.84 and 0.73; 95% CI 0.59-0.90, respectively), while the miscarriage rate was increased (RR 1.48; 95% CI 1.17-1.86). In stimulated cycles with several CLs, the mean luteal progesterone level in the no OP and no LB groups was significantly lower than in the OP and LB groups [difference in means 68.8 (95% CI 45.6-92.0) and 272.4 (95% CI 10.8-533.9), ng/ml, respectively]. Monitoring luteal serum progesterone levels could help in individualizing progesterone administration to enhance OP and LB rates, especially in cycles without corpus luteum.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=139019, identifier 139019.

Recent advances in electrospun nanofiber vaginal formulations for women's sexual and reproductive health

Electrospinning is an innovative technique that allows production of nanofibers and microfibers by applying a high voltage to polymer solutions of melts. The properties of these fibers - which include high surface area, high drug loading capacity, and ability to be manufactured from mucoadhesive polymers - may be particularly useful in a myriad of drug delivery and tissue engineering applications. The last decade has witnessed a surge of interest in the application of electrospinning technology for the fabrication of vaginal drug delivery systems for the treatment and prevention of diseases associated with women's sexual and reproductive health, including sexually transmitted infections (e.g. infection with human immunodeficiency virus and herpes simplex virus) vaginitis, preterm birth, contraception, multipurpose prevention technology strategies, cervicovaginal cancer, and general maintenance of vaginal health. Due to their excellent mechanical properties, electrospun scaffolds are also being investigated as next-generation materials in the surgical treatment of pelvic organ prolapse. In this article, we review the latest advances in the field.

Analysis of serum and endometrial progesterone in determining endometrial receptivity

STUDY QUESTION

Is there a relationship between serum and endometrial progesterone (P4) levels, including P4 and metabolites (oestrone, oestradiol and 17α-hydroxyprogesterone), and endometrial receptivity?

SUMMARY ANSWER

Serum P4 levels were not correlated with endometrial P4, nor associated with endometrial receptivity as determined by the ERA® test; however, endometrial P4 and 17α-hydroxyprogesterone levels were positively correlated and related to endometrial receptivity by ERA.

WHAT IS KNOWN ALREADY

Acquisition of endometrial receptivity is governed by P4, which induces secretory transformation. A close relationship between serum P4 and pregnancy outcome is reported for hormone replacement therapy (HRT) cycles. However, the relationship between serum and uterine P4 levels has not been described, and it is unknown whether uterine receptivity depends more on serum or uterine P4 levels.

STUDY DESIGN, SIZE, DURATION

A prospective cohort study was performed during March 2018-2019 in 85 IVF patients undergoing an evaluation-only HRT cycle with oestradiol valerate (6 mg/day) and micronised vaginal progesterone (400 mg/12 h).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients were under 50 years of age, had undergone at least one failed IVF cycle, had no uterine pathology, and had adequate endometrial thickness (> 6.5 mm). The study was conducted at IVI Valencia and IVI Foundation. An endometrial biopsy and a blood sample were collected after 5 days of P4 vaginal treatment. Measures included serum P4 levels, ERA®-based evaluation of endometrial receptivity, and endometrial P4 levels along with metabolites (oestrone, oestradiol and 17α-hydroxyprogesterone) measured by ultra-performance liquid chromatography-tandem mass spectrometry.

MAIN RESULTS AND THE ROLE OF CHANCE

Seventy-nine women were included (mean age: 39.9 ± 4.6, BMI: 24.2 ± 3.9 kg/m2, endometrial thickness: 8.2 ± 1.4 mm). The percentage of endometria indicated as receptive by ERA® was 40.5%. When comparing receptive versus non-receptive groups, no differences were observed in baseline characteristics nor in steroid hormones levels in serum or endometrium. No association between serum P4 and endometrial steroid levels or ERA result was found (P < 0.05). When the population was stratified according to metabolite concentration levels, endometrial P4 and 17α-hydroxyprogesterone were significantly associated with endometrial receptivity (P < 0.05). A higher proportion of receptive endometria by ERA was observed when endometrial P4 levels were higher than 40.07 µg/ml (relative maximum) and a lower proportion of receptive endometria was associated with endometrial 17α-hydroxyprogesterone lower than 0.35 ng/ml (first quartile). A positive correlation R2 = 0.67, P < 0.001 was observed between endometrial P4 and 17α-hydroxyprogesterone levels.

LIMITATIONS, REASONS FOR CAUTION

This study did not analyse pregnancy outcomes. Further, the findings can only be extrapolated to HRT cycles with micronised vaginal progesterone for luteal phase support.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest that the combined benefits of different routes of progesterone administration for luteal phase support could be leveraged to ensure an adequate concentration of progesterone both in the uterus and in the bloodstream. Further studies will confirm whether this method can optimise both endometrial receptivity and live birth rate. Additionally, targeted treatment to increase P4 endometrial levels may normalise the timing of the window of implantation without needing to modify the progesterone administration day.

STUDY FUNDING/COMPETING INTEREST(S)

This research was supported by the IVI-RMA Valencia (1706-VLC-051-EL) and Consellería d'Educació, Investigació, Cultura, i esport Generalitat Valenciana (Valencian Government, Spain, GV/2018//151). Almudena Devesa-Peiro (FPU/15/01398) and Cristina Rodriguez-Varela (FPU18/01657) were supported by the FPU program fellowship from the Ministry of Science, Innovation and Universities (Spanish Government). P.D.-G. is co-inventor on the ERA patent, with non-economic benefits. The other authors have no competing interests.

TRIAL REGISTRATION NUMBER

NCT03456375.

Serum luteal phase progesterone in women undergoing frozen embryo transfer in assisted conception: a systematic review and meta-analysis

OBJECTIVE

To investigate the association between luteal serum progesterone levels and frozen embryo transfer (FET) outcomes.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Women undergoing FET.

INTERVENTION(S)

We conducted electronic searches of MEDLINE, PubMed, CINAHL, EMBASE, the Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Web of Science, ClinicalTrials.gov, and grey literature (not widely available) from inception to March 2021 to identify cohort studies in which the serum luteal progesterone level was measured around the time of FET.

MAIN OUTCOME MEASURE(S)

Ongoing pregnancy or live birth rate, clinical pregnancy rate, and miscarriage rate.

RESULT(S)

Among the studies analyzing serum progesterone level thresholds <10 ng/mL, a higher serum progesterone level was associated with increased rates of ongoing pregnancy or live birth (relative risk [RR] 1.47, 95% confidence interval [CI] 1.28 to 1.70), higher chance of clinical pregnancy (RR 1.31, 95% CI 1.16 to 1.49), and lower risk of miscarriage (RR 0.62, 95% CI 0.50 to 0.77) in cycles using exclusively vaginal progesterone and blastocyst embryos. There was uncertainty about whether progesterone thresholds ≥10 ng/mL were associated with FET outcomes in sensitivity analyses including all studies, owing to high interstudy heterogeneity and wide CIs.

CONCLUSION(S)

Our findings indicate that there may be a minimum clinically important luteal serum concentration of progesterone required to ensure an optimal endocrine milieu during embryo implantation and early pregnancy after FET treatment. Future clinical trials are required to assess whether administering higher-dose luteal phase support improves outcomes in women with a low serum progesterone level at the time of FET.

PROSPERO NUMBER

CRD42019157071.

Enhanced drug delivery to the reproductive tract using nanomedicine reveals therapeutic options for prevention of preterm birth

Inflammation contributes to nearly 4 million global premature births annually. Here, we used a mouse model of intrauterine inflammation to test clinically used formulations, as well as engineered nanoformulations, for the prevention of preterm birth (PTB). We observed that neither systemic 17a-hydroxyprogesterone caproate (Makena) nor vaginal progesterone gel (Crinone) was sufficient to prevent inflammation-induced PTB, consistent with recent clinical trial failures. However, we found that vaginal delivery of mucoinert nanosuspensions of histone deacetylase (HDAC) inhibitors, in some cases with the addition of progesterone, prevented PTB and resulted in delivery of live pups exhibiting neurotypical development. In human myometrial cells in vitro, the P4/HDAC inhibitor combination both inhibited cell contractility and promoted the anti-inflammatory action of P4 by increasing progesterone receptor B stability. Here, we demonstrate the use of vaginally delivered drugs to prevent intrauterine inflammation-induced PTB resulting in the birth of live offspring in a preclinical animal model.

Landscape of Preterm Birth Therapeutics and a Path Forward

Preterm birth (PTB) remains the leading cause of infant morbidity and mortality. Despite 50 years of research, therapeutic options are limited and many lack clear efficacy. Tocolytic agents are drugs that briefly delay PTB, typically to allow antenatal corticosteroid administration for accelerating fetal lung maturity or to transfer patients to high-level care facilities. Globally, there is an unmet need for better tocolytic agents, particularly in low- and middle-income countries. Although most tocolytics, such as betamimetics and indomethacin, suppress downstream mediators of the parturition pathway, newer therapeutics are being designed to selectively target inflammatory checkpoints with the goal of providing broader and more effective tocolysis. However, the relatively small market for new PTB therapeutics and formidable regulatory hurdles have led to minimal pharmaceutical interest and a stagnant drug pipeline. In this review, we present the current landscape of PTB therapeutics, assessing the history of drug development, mechanisms of action, adverse effects, and the updated literature on drug efficacy. We also review the regulatory hurdles and other obstacles impairing novel tocolytic development. Ultimately, we present possible steps to expedite drug development and meet the growing need for effective preterm birth therapeutics.

Avoiding a Sticky Situation: Bypassing the Mucus Barrier for Improved Local Drug Delivery

The efficacy of drugs administered by traditional routes is limited by numerous biological barriers that preclude reaching the intended site of action. Further, full body systemic exposure leads to dose-limiting, off-target side effects. Topical formulations may provide more efficacious drug and nucleic acid delivery for diseases and conditions affecting mucosal tissues, but the mucus protecting our epithelial surfaces is a formidable barrier. Here, we describe recent advances in mucus-penetrating approaches for drug and nucleic acid delivery to the ocular surface, the female reproductive tract, the gastrointestinal tract, and the airways.

Development of intravaginal rod insert bearing liposomal raloxifene hydrochloride and Leuprolide acetate as a potential carrier for uterine targeting

OBJECTIVES

This project aimed at the formulation of dual drug entrapped liposomes held as freeze-dried intravaginal rod insert (IVR), to be administered by vaginal route for uterine targeting.

METHODS

Liposomes were formulated by dehydration-rehydration method using 3 : 1 molar ratio of1,2-distearoyl-sn-glycero-3-phosphocholine : Cholesterol. Characterization was done for vesicle size, zeta potential, entrapment efficiency, surface morphology and % loading.

KEY FINDINGS

Spherical and discrete vesicles of size 354 nm were observed in transmission electron microscopy (TEM) image. The entrapment efficiency of 90.91% and 74.3% w/w was obtained for Raloxifene Hydrochloride (RLX) and Leuprolide acetate (LA) respectively. Drug release was sustained for 6 days. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay results showed that dual drug entrapped liposomal formulation show significant cytotoxicity, as also confirmed by higher apoptosis in cell cycle analysis and apoptosis studies (FACS) analysis. Pharmacodynamic studies in New Zealand white female rabbits revealed that intravaginal administration of RLX-LA entrapped liposomal formulation shows considerable fibroid regression.

CONCLUSIONS

Uterine targeting of liposomal RLX-LA suggests its potential to solve the limitations of the presently available therapeutic options.

Women utilizing oocyte donation have a decreased live birth rate if they displayed a low progesterone level in a previous hormonal replacement mock cycle

PURPOSE

Is serum progesterone(P) level on day 2 of vaginal P administration in a hormonally substituted mock cycle predictive of live birth in oocyte donation(OD)?

METHODS

Retrospective analysis of 110 mock cycles from 2008 to 2016 of OD recipients having at least one subsequent embryo transfer (ET). Endometrial preparation consisted of sequential administration of vaginal estradiol, followed by transdermal estradiol and 600 mg/day vaginal micronized P. In mock cycles, serum P was measured 2 days after vaginal P introduction. OD was performed 1 to 3 years later, without P measurement.

RESULTS

In mock cycles, mean serum P level on day 2 was 12.8 ± 4.5 ng/mL (range: 4-28 ng/mL). A total of 32% patients had P < 10 ng/mL. At the time of first OD, age of recipients and donors, number of retrieved and attributed oocytes, and number of transferred embryos were comparable between patients with P < 10 ng/mL in their mock cycles compared with P ≥ 10 ng/mL. Pregnancy and live birth rate after first ET were significantly lower for patients with P < 10ng/mL (9% vs. 35 %; P = 0.002 and 9% vs. 32%; P = 0.008, respectively). Considering both fresh and subsequent frozen-thawed ET, cumulative live birth rate per-patient and per-transfer were significantly lower in patients with P < 10 ng/mL in their mock cycle (14% vs. 35%; P = 0.02 and 11% vs. 27%; P = 0.03).

CONCLUSION

A low P level in hormonally substituted cycles several years before ET performed with the same endometrial preparation is associated with a significantly lower chance of live birth. This suggests that altered vaginal P absorption is a permanent phenomenon. Monitoring serum P in hormonally substituted cycles appears mandatory to adjust luteal P substitution.

Novel drug delivery methods for improving efficacy of endometriosis treatments

INTRODUCTION

Pharmacotherapy has a key role in the management of endometriosis. However, a significant proportion of patients gains only intermittent or limited benefits. In this regard, alternative and novel drug delivery methods are of paramount importance to improve efficacy and compliance of available treatments and develop alternative medical approaches.

AREAS COVERED

This review aims to provide the reader with a complete overview of available evidence about alternative and novel drug delivery methods for endometriosis pharmacotherapy and highlight new research lines.

EXPERT OPINION

Progestins and estroprogestins, which represent the first-line therapy, are already available in different formulations, being employed for contraception. Nevertheless, evidence on their adoption is still limited for some drug delivery methods, such as vaginal rings, patches, and subcutaneous implants. Further research is needed to define better their clinical utility in patients with endometriosis. Nanotechnologies have been investigated as novel drug delivery methods able to target the drug at the disease level. However, data are very limited and preliminary, and further research is needed to consider a possible clinical application in endometriosis.

Comparing pregnancy outcomes between natural cycles and artificial cycles following frozen-thaw embryo transfers

BACKGROUND

Frozen embryo transfer (FET) is increasing in prevalence. In contrast to the amount of research performed on the actual cryopreservation procedure, there are limited data with respect to optimal endometrial preparation in FET cycles. Increasingly artificial cycle (AC) preparation is being adopted over the natural cycle (NC) to facilitate greater access to FET. However, there remains a paucity of data comparing pregnancy outcomes between these two commonly used cycle types.

AIMS

To examine the efficacy of AC vs NC following FET, by comparing pregnancy outcomes including biochemical, clinical and live birth rates, along with miscarriage rates.

MATERIALS AND METHOD

This is a large single-centre retrospective analysis, examining a standardised data set from January 2015 to July 2018. It included 3030 cycles (NC = 2033, AC = 997). Main outcomes were biochemical pregnancy (beta-human chorionic gonadotropin > 5 IU), ultrasound-diagnosed clinical pregnancy, and live births. Using the χ² test, the above pregnancy outcomes were compared between AC and NC. A multivariate logistic regression, controlling for factors such as age, embryo quality, and day of blastocyst freeze was further utilised to assess for confounding variables.

RESULTS

No difference was observed between biochemical pregnancy rates (NC = 39.45% vs AC = 37.71%, P = 0.357); statistically significant differences were observed between clinical pregnancy (30.84% vs 26.08%, P = 0.007), and live birth rates (24.40% vs 18.86% P = 0.001). Multivariate analysis confirmed that NC produces superior pregnancy outcomes when controlling for confounding variables.

CONCLUSION

This analysis demonstrates the non-inferiority of NC thaw compared to AC, on continuing pregnancy rates. Taken together with patient acceptability and possibly increased obstetric risks with AC, these findings support the use of NC when medically possible.

Do serum progesterone levels on day of embryo transfer influence pregnancy outcomes in artificial frozen-thaw cycles?

PURPOSE

The purpose of this study is to investigate whether progesterone (P4) levels on the day of frozen-thawed embryo transfer (FET) to a hormonally prepared endometrium correlate with pregnancy outcomes.

METHODS

This is a large retrospective cohort analysis comprising of N = 2010 FETs. In these cycles, P4 levels on the day of transfer were assessed in relation to pregnancy outcomes. A threshold of 10 ng/mL was used to simulate currently accepted levels for physiological corpus luteal function. Biochemical pregnancy, clinical pregnancy, and live birth rates were compared between those with P4 levels above and below this threshold. Analyses using transfer day P4 thresholds of 5 ng/mL and 20 ng/mL were then completed to see if these could create further prognostic power.

RESULTS

When comparing FET outcomes in relation to P4 levels < 10 ng/mL and ≥ 10 ng/mL, we observed no differences in biochemical pregnancy rates (39.53% vs. 40.98%, p = 0.52), clinical pregnancy rates (20.82 vs. 22.78, p = 0.30), and live birth rates (14.25 vs. 16.21 p = 0.23). In patients whose P4 met the threshold of 20 ng/mL, there was similarly no statistically significant improvement in pregnancy outcomes. While there was no difference for biochemical or clinical pregnancy rates, a statistically significant improvement in live birth rates was observed for those with a transfer day P4 level ≥ 5 ng/mL.

CONCLUSIONS

We demonstrated that P4 levels at or above 10 ng/mL on the day of FET do not confer a statistically significant improvement in pregnancy outcomes. P4 below 5 ng/mg was associated with lower live birth rates suggesting that there is a threshold below which it is difficult to salvage FET cycles.

[Progesterone and frozen-thawed embryo transfer after hormonal replacement therapy for endometrial preparation: An update on medical practices]

Frozen-thawed embryo transfer (FET) has recently become the most frequently performed ART procedure. Many protocols for endometrial preparation are used, without any evidence-based superiority of one protocol above the others. Most French fertility centers mainly use hormonal replacement treatment (HRT) for endometrial preparation for organizational reasons. According to some studies, early pregnancy losses rate is higher with HRT endometrial preparation for FET than with other protocols, leading to new insights in improving outcomes into ART centers. There is a lack of consensual guidelines regarding the use of HRT for FET: there are various protocols, with different dosages, duration and routes for progesterone (PG) prescription. To date, the vaginal route is the most popular around the world as it gives higher intra-uterine concentration of PG because of the first uterine pass. However, recent scientific publications have pointed the importance of PG measurement in order to detect a lack of PG supplementation. Whatever the route of administration, it seems that a significant proportion of patients do not reach adequate PG concentrations for successful implantation and ongoing pregnancy. Timing of the measurement and ideal serum PG rate to reach are yet to be defined. What treatment strategy to adopt according to the results is still under investigation. Individualization of PG doses and routes of administration could lead to a decrease in miscarriages and better outcome.

Progesterone for the Prevention of Preterm Birth - an Update of Evidence-Based Indications

The prevention and treatment of preterm birth remains one of the biggest challenges in obstetrics. Worldwide, 11% of all children are born prematurely with far-reaching consequences for the children concerned, their families and the health system. Experimental studies suggest that progesterone inhibits uterine contractions, stabilises the cervix and has immunomodulatory effects. Recent years have seen the publication of numerous clinical trials using progestogens for the prevention of preterm birth. As a result of different inclusion criteria and the use of different progestogens and their methods of administration, it is difficult to draw comparisons between these studies. A critical evaluation of the available studies was therefore carried out on the basis of a search of the literature (1956 to 09/2018). Taking into account the most recent randomised, controlled studies, the following evidence-based recommendations emerge: In asymptomatic women with singleton pregnancies and a short cervical length on ultrasound of ≤ 25 mm before 24 weeks of gestation (WG), daily administration of vaginal progesterone (200 mg capsule or 90 mg gel) up until 36 + 6 WG leads to a significant reduction in the preterm birth rate and an improvement in neonatal outcome. The latest data also suggest positive effects of treatment with progesterone in cases of twin pregnancies with a short cervical length on ultrasound of ≤ 25 mm before 24 WG. The study data for the administration of progesterone in women with singleton pregnancies with a previous preterm birth have become much more heterogeneous, however. It is not possible to make a general recommendation for this indication at present, and decisions must therefore be made on a case-by-case basis. Even if progesterone use is considered to be safe in terms of possible long-term consequences, exposure should be avoided where it is not indicated. Careful patient selection is crucial for the success of treatment.

17-α Hydroxyprogesterone Nanoemulsifying Preconcentrate-Loaded Vaginal Tablet: A Novel Non-Invasive Approach for the Prevention of Preterm Birth

Preterm birth (PTB) is a major cause of infant mortality in the United States and around the globe. Makena^®—once-a-week intramuscular injection of 17-α Hydroxyprogesterone caproate (17P)—is the only FDA approved treatment for the prevention of PTB. Invasive delivery of 17P requires hospitalization and expert personnel for injection. Vaginal delivery of 17P would be preferable, because of high patient compliance, reduced systemic exposure, fewer side effects, and no need for hospitalization. The objective of the present study was to prepare and evaluate a self-nanoemulsifying vaginal tablet of 17P. A solid self-nanoemulsifying preconcentrate (S-SNEDDS) of 17P and dimethylacetamide (DMA) was developed using medium chain triglycerides, a non- immunogenic surfactant, and co-processed excipient (PVA-F100). The tablet prepared was characterized for emulsification time, particle size, solid state properties, and drug release. The formulation showed >50% inhibition of TNF-α release from LPS-stimulated RAW 264.7 cells. Importantly, there were significant differences in rates of PTB and average time to delivery between control and vaginal 17P-treated groups in LPS-stimulated timed pregnant E15.5 mice. Considering the lacuna of therapeutic approaches in this area, vaginal delivery of 17P for the prevention of preterm birth has significant clinical relevance.

Evaluation of progestogen supplementation for luteal phase support in fresh in vitro fertilization cycles

OBJECTIVE

To evaluate the effectiveness of progestogen supplementation in improving clinical pregnancy rates in women undergoing fresh IVF cycles and to compare different routes, start times, durations, and estrogen coadministration regimen.

DESIGN

Comprehensive systematic review and meta-analysis.

SETTING

University.

PATIENT(S)

Women undergoing fresh IVF cycles who did and did not receive progestogen supplementation.

INTERVENTION(S)

Summary odds ratios (ORs) were calculated by binomial logistic regression.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rates.

RESULT(S)

Eighty-two articles (26,726 women) were included. Clinical pregnancy rates were increased by IM (OR = 4.57), vaginal (OR = 3.34), SC (OR = 3.36), or oral (OR = 2.57) progestogen supplementation versus no treatment. The greatest benefit was observed when progestogens were supplemented IM versus vaginally (OR = 1.37). The optimal time to commence administration was between oocyte retrieval and ET (OR = 1.31), with oocyte retrieval +1 day being most beneficial. Coadministration of estrogen had no benefit (OR = 1.33), whether progestogens were coadministered vaginally or IM. Clinical pregnancy rates were equivalent when progestogen supplementation was ceased after ≤3 weeks or continued for up to 12 weeks (OR = 1.06).

CONCLUSION(S)

This broad-ranging meta-analysis highlights the need to reevaluate current clinical practice. The use of progestogens in fresh IVF cycles is substantially beneficial to clinical pregnancy. Critically, the use of IM progestogens should not be dismissed, as it yielded the greatest clinical pregnancy rates. Pregnancy success was impacted by initiation of therapy, with 1 day after oocyte retrieval being optimal. There is little evidence to support coadministration of estrogen or prolonging progestogen treatment beyond 3 weeks.

Progesterone - Effective for Tocolysis and Maintenance Treatment After Arrested Preterm Labour?: Critical Analysis of the Evidence

Numerous experimental studies indicate that natural progesterone, through various mechanisms, exerts an inhibitory effect on uterine contractility and sensitises the myometrium for tocolytics. It was therefore appropriate to investigate the possible benefits of oral/vaginal progesterone and the synthetic progesterone derivative 17-α-hydroxyprogesterone caproate, applied intramuscularly, in clinical studies on primary tocolysis, additively to established tocolytics ("adjunctive tocolysis") and as maintenance treatment after successful tocolysis in cases of threatened preterm birth. Three studies with a small number of cases do not yield any sufficient evidence for recommending progesterone/17-α-hydroxyprogesterone caproate as primary tocolysis in women with preterm labour. There is also no evidence that progesterone or 17-α-hydroxyprogesterone caproate combined with commonly used tocolytics leads to a prolongation of pregnancy and a significant decrease in the rate of preterm birth. The data on the use of progesterone as maintenance treatment is controversial. While randomised, controlled studies with low quality showed promising results, studies with high quality did not reveal any significant differences with regard to the rate of preterm birth < 37 weeks of gestation, the latency period until delivery and in the neonatal outcome between progesterone/17-α-hydroxyprogesterone caproate and placebo or no treatment. Significant differences in the methodology, the inclusion and outcome criteria, the mode of application and the dosages of the substances as well as the inadequate statistical power as a result of low numbers of cases make interpretation and comparability of the studies difficult. Therefore, well-designed randomised, placebo-controlled, double-blind studies with uniform primary outcome criteria are needed in order to clarify whether progesterone and via which route of administration and at which dosage is of clinical benefit for patients with manifest preterm contractions and as maintenance treatment after arrested preterm labour.

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.

Novel in situ gelling vaginal sponges of sildenafil citrate-based cubosomes for uterine targeting

Sildenafil citrate (SIL), a type 5-specific phosphodiesterase inhibitor, demonstrates valuable results in the management of infertility in women; however, the absence of vaginal dosage form in addition to the associated oral adverse effects minimize its clinical performance. The present study is concerned with SIL uterine targeting following intravaginal administration via optimization of cubosomal in situ gelling sponges (CIS). An emulsification method was employed for preparation of cubosomal dispersions incorporating glyceryl monooleate as a lipid phase and poloxamer 407 as a surfactant with or without polyvinyl alcohol as a stabilizer. Cubosomes were estimated regarding entrapment efficiency (EE%), particle size, and in vitro drug release. Chitosan (2% w/w) was incorporated into the optimum formulation and then lyophilized into small sponges. For the CIS, in vivo histopathological and pharmacokinetic studies were conducted on female Wistar rats and compared with intravaginal free SIL sponges (FIS) and oral SIL solution. SIL-loaded cubosomes showed EE% ranging between 32.15 and 72.01%, particle size in the range of 150.81–446.02 nm and sustained drug release over 8 h. Histopathological study revealed a significant enlargement in endometrial thickness with congestion and dilatation of endometrial blood vessels in intravaginal CIS compared to intravaginal FIS and oral-treated groups. The pharmacokinetic study demonstrated higher AUC_0–∞ and C_max with oral administration compared to intravaginal CIS or intravaginal FIS indicating potential involvement of first uterine pass effect after intravaginal administration. Finally, intravaginal CIS could be considered as a promising platform for SIL uterine targeting with minimized systemic exposure and side effects.

Vaginal drug delivery for the localised treatment of cervical cancer

Cervical cancer is usually treated by surgery, with the more advanced cancers requiring adjuvant chemotherapy or radiotherapy. The location of the cervix makes it easily accessible through the vagina for the localised delivery of chemotherapeutic drugs. Localised delivery has the advantage of direct delivery to the site of action resulting in a lower dose having to be required and a reduction in systemic side effects. This approach would be advantageous for fertility sparing surgery, whereby localised delivery could be used to reduce tumour size allowing for a much smaller tumour to be removed, reducing the risk of preterm birth. Furthermore, localised delivery could be used after surgery to reduce the risk of recurrence, which is significantly higher in fertility sparing surgery compared to standard surgery. In this paper, we discuss the number of vaginal dosage forms that have investigated for this purpose, including tablets, rings, bioadhesive and cervical caps. APIs under investigation have ranged from well-established chemotherapeutic drugs to more experimental compounds.

A randomised trial to compare 200 mg micronised progesterone effervescent vaginal tablet daily with 250 mg intramuscular 17 alpha hydroxy progesterone caproate weekly for prevention of recurrent preterm birth

For prevention of a recurrent preterm birth (PTB), intramuscular 17-α-hydroxy progesterone caproate (IM 17 OHPC) weekly is recommended. Vaginal progesterone is preferred for women at risk for PTB due to a short cervical length, but may be useful in women with a prior PTB. However, there is no consensus about the optimal vaginal formulation or its efficacy as compared to 17 OHPC to prevent recurrent PTB. We randomised 100 women with a singleton pregnancy between 16 and 24 weeks of gestation and ≥ one prior spontaneous PTB, of a singleton (>16 to <37 weeks of gestation) to receive the 200 mg vaginal progesterone effervescent tablet daily (Group A) or IM 17-OHPC, 250 mg weekly (Group B) till 37 weeks of gestation or delivery. The spontaneous PTB rate of <37 weeks was similar (20% in Group A and 20.8% in Group B, p =  .918). The PTB rate of <34 weeks or <28 weeks were also comparable. The mean birth weight and other neonatal outcomes were similar in the two groups. Two neonates in Group A and four neonates in Group B required NICU admission, one of whom (Group B) died due to prematurity. Twenty percent of women in Group A and 29.2% in Group B reported adverse effects from their respective study medications (p =  .408, NS). Thus, there did not appear to be a difference between vaginal progesterone and 17-OHPC when used for the prevention of a recurrent PTB. Impact statement What is already known on this subject? Progesterone administration is useful for prevention of a recurrent preterm birth (PTB) and these women are prescribed the intramuscular 17-α-hydroxy progesterone caproate (IM 17 OHPC), 250 mg, weekly. Some studies found that vaginal progesterone (once daily) is also beneficial in these women, but there is no consensus regarding its efficacy when compared to 17 OHPC, or its optimal formulation and dose. What do the results of this study add? In the present study, 100 women with a singleton pregnancy between 16 and 24 weeks of gestation and ≥ one prior spontaneous singleton PTB or mid-trimester abortion were randomised to receive 200 mg of vaginal progesterone effervescent tablet daily (Group A) or 250 mg IM 17-OHPC weekly (Group B) till 37 weeks of gestation or delivery. The spontaneous PTB rate <37 weeks was similar in the two groups (20% in Group A and 20.8% in Group B, p = .918). The PTB rate <34 weeks or <28 weeks were also comparable. The mean birth weight and other neonatal outcomes were similar. Twenty percent of women in Group A and 29.2% of women in Group B reported adverse effects from their respective study medications (p = .408, NS). Thus, there did not appear to be a difference between the vaginal progesterone effervescent tablet and 17-OHPC when used for the prevention of a recurrent PTB. What are the implications of these findings for clinical practice and/or further research? The vaginal progesterone effervescent tablet may be a suitable alternative to IM 17 OHPC to prevent recurrent PTB. Future studies should identify the most appropriate route (IM or vaginal) and vaginal progesterone formulation for PTB prevention in women at risk for a recurrent PTB and in women with a short cervical length.

Menopausal hormone therapy: a better and safer future

Major advances in menopause hormone therapy (MHT) hold promise in the future of better and safer care for women at and after the menopause. The principal advances are: (1) the critical window or 'window of opportunity' in the 10 years or so after the menopause, during which the benefits of MHT in healthy women exceed any risks; (2) use of transdermal instead of oral administration of estrogen to reduce the risk of venous thromboembolism; (c) investigation of the use of oral micronized progesterone (MP) and vaginal MP to prevent endometrial hyperplasia and carcinoma without any increased risk of breast cancer and venous thromboembolism in postmenopausal women receiving estrogens; vaginal MP prevents endometrial proliferation in the short term but the long-term effects in MHT remain to be established; (4) investigation into the use of intrauterine levonorgestrel-releasing devices (LNG-IUDs), which are an attractive form of MHT in perimenopausal women, providing contraception and reducing uterine bleeding, although the risk of breast cancer with LNG-IUDs requires clarification. Women in the future can look forward to a symptom-free menopause and to safer and more beneficial MHT.

Optimal routes of administration, vehicles and timing of progesterone treatment for inhibition of delivery during pregnancy

OBJECTIVES

Progestins, notably progesterone (P4) and 17 alpha hydroxyprogesterone caproate, are presently used to treat pregnant women at risk of preterm birth. The aim of this study was to assess the optimal treatment options for progesterone (P4) to delay delivery using a sensitive bioassay for progesterone.

STUDY DESIGN

Pregnant rats, known to be highly sensitive to progestins, were treated with P4, including Prochieve^® (also known as Crinone^®), in various vehicles from day 13 of gestation and in late gestation, days 19 to 22, and delivery times noted. Various routes of administration of P4 and various treatment periods were studied.

RESULTS

Use of micronized P4 by rectal, subcutaneous injection (sc) and topical (transdermal) administration in various oils all significantly (P<0.05-<0.001) delay delivery, but vaginal Prochieve^® did not. Administration of P4 in late gestation also prevented (P<0.001) delivery even when given 8h before delivery.

CONCLUSIONS

Prochieve^® possesses little biological activity to suppress delivery in a sensitive bioassay system and suggests that this preparation may be of little value in prevention and inhibition of preterm birth. Further, this study shows: 1) Inhibition of delivery is increased with P4 treatments when given subcutaneously or topically. 2) P4 in fish oil provides the best vehicle for topical treatment and may be an effective treatment of preterm birth. 3) P4 in fish oil also delays delivery even when treatment begins just prior to normal delivery. 4) To prevent preterm birth in pregnant women, randomized controlled studies are needed with a potent progestin using better formulations and routes of administration.

"Per vaginam" topical use of hormonal drugs in women with symptomatic deep endometriosis: a narrative literature review

PURPOSE

We aim to provide a comprehensive overview of the role of the vagina as a route for drug delivery and absorption, with a particular focus on the use of vaginal hormonal compounds for the treatment of deep infiltrating symptomatic endometriosis.

METHODS

A MEDLINE search through PubMed was performed to identify all published studies in English language on vaginal hormonal treatments for symptomatic endometriosis.

RESULTS

Main advantages of the vaginal route include avoidance of the hepatic-first pass metabolic effect, the possibility of using lower therapeutic dosages, and the reduction of side effects compared with the oral administration. Studies on endometriosis treatment mainly focused on the use of vaginal danazol (n = 6) and the contraceptive vaginal ring (n = 2). One pilot study evaluated the efficacy of vaginal anastrozole in women with rectovaginal endometriosis. Most investigations evaluated the vaginal use of hormonal agents in women with deep infiltrating endometriosis/rectovaginal endometriosis. Overall, a substantial amelioration of pelvic pain symptoms associated with endometriosis was observed, particularly of dysmenorrhea. A significant reduction in rectovaginal endometriotic nodule dimensions measured at ultrasound examination was detected by some but not all authors.

CONCLUSIONS

The vaginal route represents a scarcely explored modality for drug administration. High local hormonal concentrations might achieve a greater effect on endometriotic lesions compared with alternative routes. Future studies should focus on the use of the vagina for delivering target therapies particularly in patients with deeply infiltrating rectovaginal lesions.

Application of nanotechnology for the development of microbicides

The vaginal route is increasingly being considered for both local and systemic delivery of drugs, especially those unsuitable for oral administration. One of the opportunities offered by this route but yet to be fully utilised is the administration of microbicides. Microbicides have an unprecedented potential for mitigating the global burden from HIV infection as heterosexual contact accounts for most of the new infections occurring in sub-Saharan Africa, the region with the highest prevalent rates. Decades of efforts and massive investment of resources into developing an ideal microbicide have resulted in disappointing outcomes, as attested by several clinical trials assessing the suitability of those formulated so far. The highly complex and multi-level biochemical interactions that must occur among the virus, host cells and the drug for transmission to be halted means that a less sophisticated approach to formulating a microbicide e.g. conventional gels, etc may have to give way for a different formulation approach. Nanotechnology has been identified to offer prospects for fabricating structures with high capability of disrupting HIV transmission. In this review, predominant challenges seen in microbicide development have been highlighted and possible ways of surmounting them suggested. Furthermore, formulations utilising some of these highly promising nanostructures such as liposomes, nanofibres and nanoparticles have been discussed. A perspective on how a tripartite collaboration among governments and their agencies, the pharmaceutical industry and academic scientists to facilitate the development of an ideal microbicide in a timely manner has also been briefly deliberated.

Misoprostol for Labour Induction after Previous Caesarean Section - Forever a "No Go"?

Misoprostol in oral or vaginal form is an established method of labour induction worldwide. Its use after previous caesarean section is associated with a high rate of uterine rupture; according to international guidelines it is therefore contraindicated in this setting. However the evidence base for this recommendation comprises case reports, one randomised trial that was discontinued prematurely, and numerous low quality retrospective data analyses published between 1997 and 2004. New insights into e.g. resorption kinetics, dosage and application intervals, dose dependant uterine hyperstimulation rates, as well as increasing clinical experience with misoprostol have lead to a critical reappraisal of these "historical" studies. Accordingly the evidence supporting a ban on vaginal and particularly oral misoprostol for labour induction in the context of a scarred uterus is currently insufficient for a convincing guideline recommendation. In view of the clear advantages of misoprostol over prostaglandin E₂ (cheaper, more effective) a retrospective review of registry data should be conducted to determine the incidence of uterine rupture following misoprostol and the circumstances in which it occurs. A prospective, randomised trial could then be conducted on the basis of these findings (e.g. oral misoprostol vs. vaginal prostaglandin E₂); known risk factors for uterine rupture including the type of uterine scar would need to be taken into account when selecting patients for vaginal delivery. Until new data from well-designed studies are available, misoprostol will continue to be contraindicated in clinical guidelines for use in labour induction after previous caesarean section.

Thermosensitive progesterone hydrogel: a safe and effective new formulation for vaginal application

Purpose

The safe and functional delivery of progesterone through the vaginal route remains an unmet clinical need. The purpose of this work is to prepare a new progesterone (P4) gel for vaginal application using a thermosensitive mucoadhesive polymer, glycol chitin (GC).

Method

Thermogelling, mucoadhesive, mechanical, and viscoelastic properties of GC and the new formulation were evaluated using rheometry. In vitro release profile and the bioactivity of P4 were determined using vaginal fluid simulant (VFS) pH 4.2, and PR-reporter gene assay, respectively. In vitro safety of the formulations was tested using (VK2/E6E7) vaginal epithelial cell line and Lactobacillus Crispatus. Finally, in vivo safety and the efficacy of this formulation were evaluated using an endometrial hypoplasia mouse model.

Results

Results shows the aqueous solution of 5%; (w/v) GC loaded with 0.1%; (w/v) P4 prepared in pH 4.2, (GC-P4), forms a thermosensitive mucoadhesive hydrogel and can maintain stable physical properties at 37°C. GC-P4 gel release 50% of P4 in 4 h after exposure to VFS, and no significant decrease in % viability of VK2/E6E7 or Lactobacillus was found after exposure to 5% GC or GC-P4. GC-P4 does not exhibit obvious toxicities to vaginal tissue in vivo even after repeated application. Efficacy studies indicated that GC-P4 was capable of preventing the progression of simple endometrial hyperplasia (SEH) to complex atypical endometrial hyperplasia (CAEH) in vivo.

Conclusions

Results indicates that GC-P4 retains many characteristics for an effective vaginal delivery system for P4. Therefore we believe that GC-P4 formulation is a promising alternative to current vaginal P4 formulation.

Electronic supplementary material

The online version of this article (doi:10.1007/s11095-014-1616-8) contains supplementary material, which is available to authorized users.

Sexual absorption of vaginal progesterone: a randomized control trial

Objective. To determine if sexual intercourse reduces absorption of vaginal progesterone gel in women and to determine if progesterone is absorbed by the male during intercourse. Study Design. Prospective, randomized, cross over, controlled study of 20 reproductive-aged women and their male sexual partners randomized to receive vaginal progesterone gel (Crinone 8% gel, Actavis Inc., USA) or placebo cream. Serum progesterone for both male and female partners were measured 10 hours after intercourse. One week later, subjects were crossed over to receive the opposite formulation. In the third week, women used progesterone gel at night and abstained from intercourse. Results. Serum progesterone was significantly reduced with vaginal progesterone gel + intercourse compared with vaginal progesterone gel + abstinence (P = 0.0075). Men absorbed significant progesterone during intercourse with a female partner using vaginal progesterone gel compared to placebo (P = 0.0008). Conclusion(s). Vaginal progesterone gel is reduced in women after intercourse which may decrease drug efficacy during luteal phase support. Because men absorb low levels of progesterone during intercourse, exposure could cause adverse effects such as decreased libido. This study is registered under Clinical Trial number NCT01959464.

Pre-clinical development of a combination microbicide vaginal ring containing dapivirine and darunavir

OBJECTIVES

Combination microbicide vaginal rings may be more effective than single microbicide rings at reducing/preventing sexual transmission of HIV. Here, we report the pre-clinical development and macaque pharmacokinetics of matrix-type silicone elastomer vaginal rings containing dapivirine and darunavir.

METHODS

Macaque rings containing 25 mg dapivirine, 100 mg dapivirine, 300 mg darunavir or 100 mg dapivirine+300 mg darunavir were manufactured and characterized by differential scanning calorimetry. In vitro release was assessed into isopropanol/water and simulated vaginal fluid. Macaque vaginal fluid and blood serum concentrations for both antiretrovirals were measured during 28 day ring use. Tissue levels were measured on day 28. Ex vivo challenge studies were performed on vaginal fluid samples and IC50 values were calculated.

RESULTS

Darunavir caused a concentration-dependent reduction in the dapivirine melting temperature in both solid drug mixes and in the combination ring. In vitro release from rings was dependent on drug loading, the number of drugs present and the release medium. In macaques, serum concentrations of both microbicides were maintained between 10(1) and 10(2) pg/mL. Vaginal fluid levels ranged between 10(3) and 10(4) ng/g and between 10(4) and 10(5) ng/g for dapivirine and darunavir, respectively. Both dapivirine and darunavir showed very similar concentrations in each tissue type; the range of drug tissue concentrations followed the general rank order: vagina (1.8 × 10(3)-3.8 × 10(3) ng/g)  > cervix (9.4 × 10(1)-3.9 × 10(2) ng/g)  > uterus (0-108 ng/g)  > rectum (0-40 ng/g). Measured IC50 values were >2 ng/mL for both compounds.

CONCLUSIONS

Based on these results, and in light of recent clinical progress of the 25 mg dapivirine ring, a combination vaginal ring containing dapivirine and darunavir is a viable second-generation HIV microbicide candidate.

Management of symptomatic vulvovaginal atrophy: 2013 position statement of The North American Menopause Society

OBJECTIVE

To update and expand the previous position statement of The North American Menopause Society (NAMS) on the management of symptomatic vulvovaginal atrophy (VVA) in postmenopausal women.

METHODS

NAMS searched PubMed for medical literature on VVA published since their 2007 position statement on the role of local vaginal estrogen for treatment of vaginal atrophy in postmenopausal women. A panel of acknowledged experts in the field of genitourinary health reviewed the literature to evaluate new evidence on local estrogen as well as on other management options available or in development for symptomatic VVA. The panel's conclusions and recommendations were reviewed and approved by the NAMS Board of Trustees.

RESULTS

Symptomatic VVA can significantly impair the quality of life (QOL) of postmenopausal women and may be underdiagnosed. In most cases, it can be managed successfully. A number of over-the-counter and government-approved prescription therapies available in the United States and Canada demonstrate effectiveness, depending on the severity of VVA symptoms. These include vaginal lubricants and moisturizers, vaginal estrogen, hormone therapy, and the selective estrogen-receptor modulator ospemifene (indicated for dyspareunia). Long-term studies on the endometrial safety of local estrogen and ospemifene are lacking. Changes in the vaginal microbiome have various effects on symptoms.

CONCLUSIONS

Clinicians can improve the sexual health and QOL of postmenopausal women by educating women about, diagnosing, and appropriately managing symptomatic VVA. Choice of therapy depends on the severity of symptoms, the effectiveness and safety of therapy for the individual patient, and patient preference. Estrogen therapy is the most effective treatment for moderate to severe symptoms, although a direct comparison of estrogen and ospemifene is not available. Nonhormonal therapies available without a prescription provide sufficient relief for most women with mild symptoms. When low-dose estrogen is administered locally, a progestogen is not indicated for women without a uterus and generally is not indicated for women with an intact uterus. However, endometrial safety has not been studied in clinical trials beyond 1 year. There are insufficient data to confirm the safety of local estrogen in women with breast cancer; management of VVA should take the woman's needs and the recommendation of her oncologist into consideration. Research on the vaginal microbiome may lead to other therapies in the future.

Inhibition of embryo implantation in mice through vaginal administration of a proprotein convertase 6 inhibitor

Uterine proprotein convertase 6 (PC6) plays a critical role in embryo implantation in both mice and women. It was hypothesized that inhibiting uterine PC6 could prevent pregnancy. Vaginal administration of a PC6 inhibitor presents the ideal route for local drug delivery. A peptide-based PC6 inhibitor, C-30k-PEG Poly R that was previously shown to have properties of increased vaginal absorption and penetration was tested for its contraceptive potential in mice following vaginal administration. The study demonstrated that this approach could inhibit embryo implantation in some mice (24% completely and 47% partially inhibited).

Vaginal mifepristone for the treatment of symptomatic uterine leiomyomata: an open-label study

OBJECTIVE

To evaluate the efficacy and safety of 3 months of vaginal mifepristone treatment on leiomyoma volume and related symptoms.

DESIGN

Prospective, open-label, two tertiary centers, phase II clinical trial.

SETTING

Two tertiary medical centers in Israel.

PATIENT(S)

Thirty-three enrolled women, ages 30-53 years, diagnosed with symptomatic uterine fibroids.

INTERVENTION(S)

Patients received 10 mg mifepristone vaginally daily for 3 months.

MAIN OUTCOME MEASURE(S)

Reduction in uterine leiomyoma volume. Improvement in symptoms related to uterine fibroids was assessed with the use of the "Uterine Fibroid Symptoms Quality of Life Questionnaire" (UFS-QoL). The number of bleeding days, safety, and tolerability were secondary measures.

RESULT(S)

Mifepristone treatment significantly reduced leiomyoma volume from 135.3 ± 22.9 cc at enrollment to 101.2 ± 22.4 cc after 3 months of treatment. The UFS-QoL Score significantly decreased from 20.7 ± 0.7 at enrollment to 14.0 ± 0.8 after 3 months of treatment. The number of bleeding days significantly decreased by 3.5 days. Endometrial biopsies showed no evidence of endometrial hyperplasia or cellular atypia. There were no major side effects during the course of the study, and treatment was well tolerated.

CONCLUSION(S)

Vaginal mifepristone may offer an effective treatment option for women with symptomatic uterine leiomyoma and can improve the patients' quality of life.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00881140.