▪Objective:To evaluate the tolerance and effectiveness of transdermal estrogen for women with established postmenopausal osteoporosis and vertebral fractures. ▪Design:Double-blind, randomi...

Treatment of Postmenopausal Osteoporosis with Transdermal Estrogen

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(03)14066-4.pdf

Differential Association of Oral and Transdermal Oestrogen-Replacement Therapy With Venous Thromboembolism Risk

We conducted a dose-response study in 23 postmenopausal women to compare the physiologic effects of transdermal estradiol and oral conjugated equine estrogens. The doses studied were 25, 50, 100, and 200 micrograms of transdermal estradiol per 24 hours, and 0.625 and 1.25 mg of oral conjugated estrogens. Transdermal estradiol increased circulating concentrations of estradiol and estrone. Oral conjugated estrogens also raised the levels of estrogen, particularly estrone. Both preparations lowered gonadotropin levels, decreased the percentages of vaginal parabasal cells, increased the percentage of superficial cells, and lowered urinary calcium excretion. The effects of 0.625 and 1.25 mg of oral estrogens were similar to those of 50 and 100 micrograms of transdermal estradiol per 24 hours, respectively. Oral estrogens significantly increased circulating levels of renin substrate, sex-hormone-binding globulin, thyroxine-binding globulin, and cortisol-binding globulin; transdermal estradiol had no effect. The higher dose of oral estrogens had favorable effects on concentrations of low-density and high-density lipoproteins, but transdermal estradiol did not. Neither preparation affected any of the four clotting factors studied. These data indicate that transdermal estradiol can elicit many of the desirable actions of estrogen while avoiding the pharmacologic effects of oral estrogens on hepatic proteins.

https://www.nejm.org/doi/pdf/10.1056/NEJM198606193142505?listPDF=true

Biologic effects of transdermal estradiol.

Many postmenopausal women have been treated with ovarian hormones in an attempt to alleviate the symptoms of menopause and, more recently, in the hope of preventing osteoporosis and reducing the risk of ischemic heart disease. The postmenopausal period has been simplistically considered an endocrine-deficiency state, and replacement therapy has been seen as restoring the premenopausal endocrine milieu, but none of the available hormone-replacement regimens mimic the pattern of hormone secretion in premenopausal women. The most frequently used and most studied replacement regimen has been estrogen alone; the recent addition of progestogen provides a more nearly physiologic replacement regimen, but this . . .

Hormonal Treatment of Postmenopausal Women

Transdermal patches are now widely used as cosmetic, topical and transdermal delivery systems. These patches represent a key outcome from the growth in skin science, technology and expertise developed through trial and error, clinical observation and evidence-based studies that date back to the first existing human records. This review begins with the earliest topical therapies and traces topical delivery to the present-day transdermal patches, describing along the way the initial trials, devices and drug delivery systems that underpin current transdermal patches and their actives. This is followed by consideration of the evolution in the various patch designs and their limitations as well as requirements for actives to be used for transdermal delivery. The properties of and issues associated with the use of currently marketed products, such as variability, safety and regulatory aspects, are then described. The review concludes by examining future prospects for transdermal patches and drug delivery systems, such as the combination of active delivery systems with patches, minimally invasive microneedle patches and cutaneous solutions, including metered-dose systems.

https://bpspubs.onlinelibrary.wiley.com/doi/epdf/10.1111/bph.13059

Transdermal patches: history, development and pharmacology

Pharmacokinetics and pharmacodynamics of transdermal dosage forms of 17β-estradiol: Comparison with conventional oral estrogens used for hormone replacement

Joanne C. Balestra

Papers

Pharmacokinetics and pharmacodynamics of transdermal dosage forms of 17β-estradiol: Comparison with conventional oral estrogens used for hormone replacement