Transdermal delivery of bioidentical estrogen in menopausal hormone therapy: a clinical review

Transdermal Drug Delivery Systems (TDDS): Recent Advances and Failure Modes

Transdermal drug delivery systems (TDDS), commonly refered to as "patches", present a nonintrusive technique to provide medication without the need for invasive procedures. These products adhere to the skin and gradually release a specific dosage of medicine at a defined rate into the bloodstream. Compared with other methods of drug delivery, TDDS offer benefits such as reduced invasiveness, convenience for patients, and avoidance of the metabolic processes that occur when drugs are orally consumed. Throughout time, TDDS have been used to provide medications for various medical conditions (such as nicotine, fentanyl, nitroglycerin, and clonidine), and their potential for delivering biologics is currently being explored. This review investigates the current literature on the drug delivery efficacy of medical TDDS through the transdermal route. Additionally, the review addresses potential risks and failure modes associated with TDDS design and development as well as strategies for mitigating such risks. A thorough understanding of failure modes provides a blueprint to mitigate failure and produce high-quality efficacious therapeutics.

Addressing the Missing Links in Cardiovascular Aging

The aim of this manuscript is to provide a review of available options to enhance cardiovascular health and prevent cardiovascular disease (CVD) in the aging population using a systems-biology approach. These include the role of the gut microbiome, the early identification and removal of environmental toxins, and finally age related sex hormones and supplement replacement which all influence aging. Implementing such a comprehensive approach has the potential to facilitate earlier risk assessment, disease prevention, and even improve mortality. Further study in these areas will continue to advance our understanding and refine therapeutic interventions for a healthier cardiovascular aging process.

Oestrogen-based therapies for menopausal symptoms

PURPOSE

To summarise the dosing options, regimens, pharmacokinetics, risks and benefits of oestrogen-based therapies for the treatment of menopausal symptoms.

METHODS

A review of the literature was undertaken using multiple databases. Randomised trials, observational studies, meta-analyses and review papers were included.

RESULTS

Multiple systemic preparations of oestrogen exist and all appear comparable in terms of efficacy. They differ by pharmacokinetics and those preparations that avoid hepatic metabolism have a lower risk profile in general although their use can be limited by skin barriers or patient acceptability. All vaginal oestrogen treatments are comparable in efficacy and have not been associated with any health risks. Side-effects between all preparations differ.

CONCLUSIONS

With regards to oestrogen treatments there is not a one size fits all. Multiple treatments are available and a clinician's role is to guide and help women make evidence based, unbiased and informed choices.

Role of estrogen in the regulation of central and peripheral energy homeostasis: from a menopausal perspective

Estrogen plays a prominent role in regulating and coordinating energy homeostasis throughout the growth, development, reproduction, and aging of women. Estrogen receptors (ERs) are widely expressed in the brain and nearly all tissues of the body. Within the brain, central estrogen via ER regulates appetite and energy expenditure and maintains cell glucose metabolism, including glucose transport, aerobic glycolysis, and mitochondrial function. In the whole body, estrogen has shown beneficial effects on weight control, fat distribution, glucose and insulin resistance, and adipokine secretion. As demonstrated by multiple in vitro and in vivo studies, menopause-related decline of circulating estrogen may induce the disturbance of metabolic signals and a significant decrease in bioenergetics, which could trigger an increased incidence of late-onset Alzheimer's disease, type 2 diabetes mellitus, hypertension, and cardiovascular diseases in postmenopausal women. In this article, we have systematically reviewed the role of estrogen and ERs in body composition and lipid/glucose profile variation occurring with menopause, which may provide a better insight into the efficacy of hormone therapy in maintaining energy metabolic homeostasis and hold a clue for development of novel therapeutic approaches for target tissue diseases.

The role of menopausal hormone therapy in the prevention and treatment of low bone density in perimenopausal and postmenopausal women

PURPOSE OF REVIEW

The purpose of this review is to summarize the evidence on the benefits of menopausal hormone therapy (MHT) for the maintenance of skeletal health, prevention of osteoporosis and related fractures in peri and postmenopausal women.

RECENT FINDINGS

We will review the impact of estrogen on skeletal health as well as the physiology of bone loss during the perimenopause and postmenopause. We will then elucidate the data that include estrogen alone and combination of MHT to demonstrate that in the absence of contraindication, MHT should be considered as an option for the maintenance of skeletal health both when concomitant menopausal symptoms are present and when not.

SUMMARY

It has been well established that estrogens maintain bone mineral density (BMD) and reduce fracture risk at all sites. However, the most extensively studied form of estrogen with established fracture prevention is oral doses of synthetic estrogens. Due to the reduced risk profile, lower doses of bioidentical oral or transdermal estrogens are often preferred in clinical practice. We will highlight the current data on improvement in BMD and fracture risk reduction, including differences in formulation, dose, and route of delivery, to support a provider in the clinical decision-making process.

Assessing estrogen exposure from transdermal estradiol patch therapy using a dried urine collection and a GC-MS/MS assay

BACKGROUND

Transdermal estradiol patch therapy is often dosed based on patient reported symptoms. Although dosing based on serum estradiol concentrations has been considered, serum sampling is too invasive and inconvenient to use in real-world settings. The primary aim of this study was to determine if a dried urine assay could be used to assess estrogen exposure resulting from transdermal estradiol patch therapy at increasing doses.

METHODS

This was a retrospective analysis of clinical laboratory data. Urinary estrogen profiles of postmenopausal women being treated with transdermal estradiol patches at differing doses (age = 56.8 ± 7.5) were selected from the database along with the profiles of women on no therapy for comparison (age = 55.1 ± 9.5). Metabolite concentrations were obtained using a multi-spot dried urine collection and a gas chromatography-tandem mass spectrometry assay. The Jonckheere-Terpstra test was used to assess for ordered differences across dose groups to determine if dose-dependent increases in urinary estrogens occurred with increasing doses.

RESULTS

Median concentrations of estradiol and other estrogen metabolites increased with increasing doses of transdermal estradiol patch therapy (p < 0.001; Jonckheere-Terpstra test). For women who collected samples before and after initiating therapy, there were significant differences between before and after concentrations of estradiol and other estrogen metabolites.

CONCLUSION

This large study conducted using real-world data demonstrated that a dried urine assay offers a viable method of assessing estrogen exposure differences that occur with the use of differing doses of transdermal estradiol patches. Further studies with prospective designs that include outcome measures are needed to confirm the findings of this study.

Drugs for the treatment of postmenopausal symptoms: Hormonal and non-hormonal therapy

Postmenopausal symptoms are systemic symptoms associated with estrogen deficiency after menopause. At present, treatments for postmenopausal symptoms include hormonal therapy (HT) and non-HT. However, the optimal regimen for balancing the benefits and risks remains unclear. This article reviewed the characteristics, regimens, and side effects of drugs used in hormonal and non-HT. However, HT is still the most effective treatment with safety in early initiation since menopause onset. Nevertheless, it is essential to evaluate the risks of related chronic diseases and customize individualized treatments. Possible estetrol preparations and more types of Tissue Selective Estrogen Complex formulations are potential directions of drug development in the future of HT. Regarding non-HT, fezolinetant, currently in phase III clinical trials, is poised to become a first-in-class therapy for vasomotor symptoms. Ospemifene, dehydroepiandrosterone (DHEA), and vaginal lasers can also be used for moderate-to-severe genitourinary syndrome of menopause. Recent data suggest a superior efficacy and safety of vaginal lasers, but more validated evidence of long-term tolerability is needed to respond to the United States Food and Drug Administration warning. Herbal medication commonly used in Asia is effective in alleviating menopausal symptoms; however, its adverse effects still require more detailed reports and standardized observation methods. This review contributes to a better understanding of drugs for the treatment of postmenopausal symptoms and provides useful information for clinical drug selection.

Assessment of estrogen exposure from transdermal estradiol gel therapy with a dried urine assay

Transdermal estradiol gel is a commonly used menopausal hormone therapy. In research studies investigating the pharmacokinetics and clinical utility of transdermal estradiol gels, serum is often used to measure estradiol levels. Serum results only represent a moment in time during phlebotomy and thus provide little information and allow for limited inference unless serial measurements are performed. In contrast, dried urine may provide a representation of serum estradiol levels over a longer period of time, while also being non-invasive and easier to collect. The primary aim of this study was to evaluate a dried urine method to determine if it may be a viable option for evaluating estrogen exposure resulting from transdermal estradiol gel use. A secondary aim was to explore differences in the urinary estrogen profiles of premenopausal women on no therapy and postmenopausal women who were either on transdermal estradiol gel therapy or no therapy at all. The results of this study demonstrated that the expected dose-proportional changes in estrogen exposure can be observed in the urinary estrogen profile using a GC-MS/MS dried urine assay. The GC-MS/MS assay also showed the differences in the urinary estrogen profiles of premenopausal women, postmenopausal women on estrogen replacement therapy, and postmenopausal women on no therapy.

Concerns About Compounded Bioidentical Menopausal Hormone Therapy

ABSTRACT

Following the release of the Women's Health Initiative data, women began to use compounded bioidentical hormone therapy (cBHT) in the misguided belief of greater safety and efficacy than traditional hormone therapy. New guidelines recommend government-approved hormone therapy for symptomatic healthy menopausal women younger than 60 years or within 10 years of menopause at the time of initiation. For women requesting bioidentical hormones, those similar to the hormones present before menopause, there are many government-approved hormone therapies with extensive pharmacokinetic, safety, and efficacy data provided with package inserts delineating efficacy, safety, and potential risks. For women requesting non-Food and Drug Administration-approved (cBHT), these cBHTs lack data on pharmacokinetics, safety, and efficacy and are not provided a label detailing risk. Their use should be restricted to women with allergies or dosing or formulations not available in government-approved therapies. Pellet therapy providing women with supraphysiologic hormone dosing raises even more safety concerns.

Role of Estrogens in Menstrual Migraine

Migraine is a major neurological disorder affecting one in nine adults worldwide with a significant impact on health care and socioeconomic systems. Migraine is more prevalent in women than in men, with 17% of all women meeting the diagnostic criteria for migraine. In women, the frequency of migraine attacks shows variations over the menstrual cycle and pregnancy, and the use of combined hormonal contraception (CHC) or hormone replacement therapy (HRT) can unveil or modify migraine disease. In the general population, 18–25% of female migraineurs display a menstrual association of their headache. Here we present an overview on the evidence supporting the role of reproductive hormones, in particular estrogens, in the pathophysiology of migraine. We also analyze the efficacy and safety of prescribing exogenous estrogens as a potential treatment for menstrual-related migraine. Finally, we point to controversial issues and future research areas in the field of reproductive hormones and migraine.

Surgical Menopause and Estrogen Therapy Modulate the Gut Microbiota, Obesity Markers, and Spatial Memory in Rats

Menopause in human females and subsequent ovarian hormone deficiency, particularly concerning 17β-estradiol (E2), increase the risk for metabolic dysfunctions associated with obesity, diabetes type 2, cardiovascular diseases, and dementia. Several studies indicate that these disorders are also strongly associated with compositional changes in the intestinal microbiota; however, how E2 deficiency and hormone therapy affect the gut microbial community is not well understood. Using a rat model, we aimed to evaluate how ovariectomy (OVX) and subsequent E2 administration drive changes in metabolic health and the gut microbial community, as well as potential associations with learning and memory. Findings indicated that OVX-induced ovarian hormone deficiency and E2 treatment had significant impacts on several health-affecting parameters, including (a) the abundance of some intestinal bacterial taxa (e.g., Bifidobacteriaceae and Porphyromonadaceae), (b) the abundance of microbial short-chain fatty acids (SCFAs) (e.g., isobutyrate), (c) weight/BMI, and (d) high-demand spatial working memory following surgical menopause. Furthermore, exploratory correlations among intestinal bacteria abundance, cognition, and BMI underscored the putative influence of surgical menopause and E2 administration on gut-brain interactions. Collectively, this study showed that surgical menopause is associated with physiological and behavioral changes, and that E2-linked compositional changes in the intestinal microbiota might contribute to some of its related negative health consequences. Overall, this study provides novel insights into interactions among endocrine and gastrointestinal systems in the post-menopausal life stage that collectively alter the risk for the development and progression of cardiovascular, metabolic, and dementia-related diseases.

Risks, Benefits, and Treatment Modalities of Menopausal Hormone Therapy: Current Concepts

Menopausal hormone therapy (HT) prescribing practices have evolved over the last few decades guided by the changing understanding of the treatment's risks and benefits. Since the Women's Health Initiative (WHI) trial results in 2002, including post-intervention analysis and cumulative 18-year follow up, it has become clear that the risks of HT are low for healthy women less than age 60 or within ten years from menopause. For those who are experiencing bothersome vasomotor symptoms, the benefits are likely to outweigh the risks in view of HT's efficacy for symptom management. HT also has a role in preventing osteoporosis in appropriate candidates for treatment. A comprehensive overview of the types, routes, and formulations of currently available HT, as well as HT's benefits and risks by outcomes of interest are provided to facilitate clinical decision making.