Percutaneous absorption of progesterone in postmenopausal women treated with transdermal estrogen

Ability of mathematical models to predict human in vivo percutaneous penetration of steroids

Human skin is a common route for topical steroids to enter the body. To aid with risk management of therapeutic steroid usage, the US Environmental Protection Agency estimates percutaneous penetration using mathematical models. However, it is unclear how accurate are mathematical models in estimating percutaneous penetration/absorption of steroids. In this study, accuracy of predicted flux (penetration/absorption) by the main mathematical model used by the EPA, the Potts and Guy model based on in vitro data is compared to actual human in vivo data from our laboratory of percutaneous absorption of topical steroids. We focused on steroids due to the availability of steroid in vivo human data in our laboratory. For most steroids the flux was underestimated by a factor 10-60. However, within the group itself, there was an association between the Potts and Guy model and experimental human in vivo data (Pearson Correlation = 0.8925, p = 0.000041). Additionally, some physiochemical parameters used in the Potts and Guy equation, namely log Kp (Pearson Correlation = 0.7307, p = 0.0046) and molecular weight (Pearson correlation = -0.6807, p = 0.0105) correlated significantly with in vivo flux. Current mathematical models used in estimating percutaneous penetration/absorption did not accurately predict in vivo flux of steroids. Why? Proposed limitations to mathematical models currently used include: not accounting for volatility, lipid solubility, hydrogen bond effects, drug metabolism, as well as protein binding. Further research is needed in order to increase the predictive nature of such models for in vivo flux.

Hormone Therapy and Breast Cancer: Emerging Steroid Receptor Mechanisms

Although hormone therapy is widely used by millions of women to relieve symptoms of menopause, it has been associated with several side-effects such as coronary heart disease, stroke and increased invasive breast cancer risk. These side-effects have caused many women to seek alternatives to conventional hormone therapy, including the controversial custom-compounded bioidentical hormone therapy suggested to not increase breast cancer risk. Historically estrogens and the estrogen receptor were considered the principal factors promoting breast cancer development and progression, however, a role for other members of the steroid receptor family in breast cancer pathogenesis is now evident, with emerging studies revealing an interplay between some steroid receptors. In this review, we discuss examples of hormone therapy used for the relief of menopausal symptoms, highlighting the distinction between conventional hormone therapy and custom-compounded bioidentical hormone therapy. Moreover, we highlight the fact that not all hormones have been evaluated for an association with increased breast cancer risk. We also summarize the current knowledge regarding the role of steroid receptors in mediating the carcinogenic effects of hormones used in menopausal hormone therapy, with special emphasis on the influence of the interplay or crosstalk between steroid receptors. Unraveling the intertwined nature of steroid hormone receptor signaling pathways in breast cancer biology is of utmost importance, considering that breast cancer is the most prevalent cancer among women worldwide. Moreover, understanding these mechanisms may reveal novel prevention or treatment options, and lead to the development of new hormone therapies that does not cause increased breast cancer risk.

Progesterone lipid nanoparticles: Scaling up and in vivo human study

This investigation describes a scaling up study aimed at producing progesterone containing nanoparticles in a pilot scale. Particularly hot homogenization techniques based on ultrasound homogenization or high pressure homogenization have been employed to produce lipid nanoparticles constituted of tristearin or tristearin in association with caprylic-capric triglyceride. It was found that the high pressure homogenization method enabled to obtain nanoparticles without agglomerates and smaller mean diameters with respect to ultrasound homogenization method. X-ray characterization suggested a lamellar structural organization of both type of nanoparticles. Progesterone encapsulation efficiency was almost 100% in the case of high pressure homogenization method. Shelf life study indicated a double fold stability of progesterone when encapsulated in nanoparticles produced by the high pressure homogenization method. Dialysis and Franz cell methods were performed to mimic subcutaneous and skin administration. Nanoparticles constituted of tristearin in mixture with caprylic/capric triglyceride display a slower release of progesterone with respect to nanoparticles constituted of pure tristearin. Franz cell evidenced a higher progesterone skin uptake in the case of pure tristearin nanoparticles. A human in vivo study, based on tape stripping, was conducted to investigate the performance of nanoparticles as progesterone skin delivery systems. Tape stripping results indicated a decrease of progesterone concentration in stratum corneum within six hours, suggesting an interaction between nanoparticle material and skin lipids.

Treatment of postmenopausal women with topical progesterone creams and gels: are they effective?

Topical progesterone creams and gels can be obtained over the counter and/or by prescription from custom-compounding pharmacies and are used by thousands of postmenopausal women for hormonal treatment. However, the effectiveness of these preparations for protecting the endometrium from unopposed estrogen is controversial, due largely to the very low serum progesterone levels that are achieved. Despite these low serum levels, salivary and capillary blood levels are very high and a protective endometrium has been reported in a limited number of studies. Topical alcohol-based, but not water-based, gels appear to yield luteal-phase serum progesterone levels but studies with these preparations are scant. Long-term studies with percutaneous progesterone creams and gels are likely to provide valuable information for treatment of postmenopausal women with this popular route of administration.

Percutaneous progesterone delivery via cream or gel application in postmenopausal women: a randomized cross-over study of progesterone levels in serum, whole blood, saliva, and capillary blood

OBJECTIVE

This study aims to investigate the distribution of progesterone in venous whole blood, venous serum, fingertip capillary blood, and saliva after its topical application in both cream and gel formulations.

METHODS

Ten postmenopausal women were randomized to receive 80 mg of progesterone cream or gel applied daily for 14 days, crossing over after a 14-day washout. On the last day of each treatment period, venous blood, fingertip capillary blood, and saliva were sampled frequently for 24 hours after the final application.

RESULTS

After progesterone cream or gel application, serum progesterone levels rose gradually, reaching a peak at 9 and 8 hours, respectively; AUC(0-24) h was significantly higher with cream (12.39 vs 8.32 ng h mL(-1), P = 0.0391). Whole venous blood levels followed a pattern similar to that of serum but were considerably lower. Saliva progesterone showed a peak at 1 and 6 hours after cream and gel application, respectively, and C(max) was comparable with cream and gel. Saliva AUC(0-24) h was substantially higher than the corresponding area under the curve for serum or whole blood but did not differ significantly by delivery method (39.02 and 58.37 ng h mL(-1), P = 0.69). In capillary blood, C(max) was reached at the same time (8 h) and was similar with both formulations; AUC(0-24) h was also similar with both formulations (1,056 ng h mL(-1) for cream and 999 ng h mL(-1) for gel) but was dramatically higher than the corresponding areas under the curve for venous serum and whole blood.

CONCLUSIONS

After application of topical progesterone, saliva and capillary blood levels are approximately 10-fold and 100-fold greater, respectively, than those seen in serum or whole blood. High capillary blood and saliva levels indicate high absorption and transport of progesterone to tissues. Reliance on serum levels of progesterone for monitoring topical dose could lead to underestimation of tissue levels and consequent overdose.

Novel actions of progesterone: what we know today and what will be the scenario in the future?

Objectives

This article is aimed to review the novel actions of progesterone, which otherwise is considered as a female reproductive hormone. The article focuses on its important physiological actions in males too and gives an overview of its novel perspectives in disorders of central and peripheral nervous system.

Key findings

Progesterone may have a potential benefit in treatment of traumatic brain injury, various neurological disorders and male related diseases like benign prostatic hypertrophy (BPH), prostate cancer and osteoporosis. Norethisterone (NETA), a progesterone derivative, decreases bone mineral loss in male castrated mice suggesting its role in osteoporosis. In the future, progesterone may find use as a male contraceptive too, but still needs confirmatory trials for safety, tolerability and acceptability. Megestrol acetate, a progesterone derivative is preferred in prostatic cancer. Further, it may find utility in nicotine addiction, traumatic brain injury (recently entered Phase III trial) and Alzheimer's disease, diabetic neuropathy and crush injuries. Studies also suggest role of progesterone in stroke, for which further clinical trials are needed. The non genomic actions of progesterone may be in part responsible for these novel actions.

Summary

Although progesterone has shown promising role in various non-hormonal benefits, further clinical studies are needed to prove its usefulness in conditions like stroke, traumatic brain injury, neuropathy and crush injury. In male related illnesses like BPH and prostatic Ca, it may prove a boon in near future. New era of hormonal male contraception may be initiated by use of progesterone along with testosterone.

A double-blind placebo-controlled study to evaluate the effect of progestelle progesterone cream on postmenopausal women

OBJECTIVE

To evaluate the effect on climacteric symptoms and quality of life, and the safety of four doses of progestelle progesterone cream administered for 24 weeks to postmenopausal women complaining of moderate to severe menopausal symptoms. Design Single-centre, double-blind, randomized, placebo-controlled study. Population Two hundred and twenty-three healthy postmenopausal women, aged between 40 and 60 years and complaining of severe menopausal symptoms were recruited through newspaper advertisements.

METHODS

Women were randomly allocated to progestelle progesterone cream 60, 40, 20, 5 mg or placebo, to be applied daily for six months. Main outcome measures The primary efficacy variable was the psychological, somatic and vasomotor components of the Greene Climacteric Scale after six months. Secondary endpoints were incidence of hot flushes and night sweats, the nine subscales of the Medical Outcome Survey Short Form-36 (SF-36), serum progesterone, endometrial thickness and histology after six months. Adverse events were sought and recorded and followed up to resolution.

RESULTS

There were no statistically significant differences between any of the treatment groups and placebo for any of the components of the Greene Score. A statistically significant difference between the 20 mg group and placebo was found for the physical functioning (95% confidence interval [CI] 1.7-12.3; P=0.01) and social functioning (95% CI 1.9-16.7; P=0.01) scales of SF-36 after six months. No other statistically significant differences were found between any treatment group and placebo for any of the other secondary efficacy variables. There appeared to be a higher incidence of headache in the groups treated with progesterone cream.

CONCLUSIONS

Progesterone cream was no more effective than placebo for relief of menopausal symptoms.

Double-blind placebo-controlled study to evaluate the effect of pro-juven progesterone cream on atherosclerosis and bone density

Objective

To establish whether treatment for three years with pro-juven progesterone cream affects progression of atherosclerotic plaques or bone density in postmenopausal women.

Design

Randomized double-blind placebo-controlled trial.

Sample

One hundred and thirty-one healthy postmenopausal women aged between 50 and 75 years with at least one asymptomatic arterial plaque visible on ultrasound of the carotid or femoral bifurcation.

Methods

Women were randomly allocated to receive pro-juven progesterone cream, 20 mg twice daily, or placebo, for three years.

Main outcome measure

Rate of change of plaque thickness, intima-media thickness and bone density of lumbar spine and femoral neck.

Results

There was no difference between the groups.

Conclusion

Pro-juven progesterone cream 20 mg twice daily did not affect progression of asymptomatic atherosclerosis or deterioration in bone density over three years.

Bioidentical hormones for menopausal hormone therapy: variation on a theme

BACKGROUND

Progesterone creams and natural or bioidentical compounded estrogen preparations are being promoted to consumers as safe alternatives to conventional menopausal hormone therapy and as health-promoting tonics. No reliable data support these claims.

SAFETY

Natural hormones, including estradiol, estriol, estrone, and progesterone, can be expected to have the same adverse event profile as conventional menopausal hormone regimens.

SALIVARY HORMONE TESTS

Salivary tests may be used to persuade asymptomatic consumers to use hormones (or symptomatic patients to use higher doses than those needed to mitigate symptoms), a practice that can be expected to result in adverse events.

Bleeding profiles and effects on the endometrium for women using a novel combination of transdermal oestradiol and natural progesterone cream as part of a continuous combined hormone replacement regime

OBJECTIVE

Many women are seeking alternatives to conventional forms of hormone replacement. This study evaluates the endometrial effects of natural progesterone cream used in conjunction with transdermal oestradiol.

DESIGN

Open plan study conducted over 48 weeks.

SETTING

Tertiary referral London teaching hospital.

POPULATION

Women at least two years postmenopausal.

METHODS

Women were recruited nationally. They applied 40 mg transdermal natural progesterone cream and 1 mg transdermal oestradiol daily.

MAIN OUTCOME MEASURES

Endometrial histology, assessed by pipelle endometrial biopsy, ultrasound assessment of endometrial thickness and bleeding diaries.

RESULTS

Fifty-four women were recruited of which 41 completed the study. Mean age was 57.4 years. Thirty-two percent of women had evidence of inadequate endometrial opposition (proliferative or hyperplastic) at the end of 48 weeks. At baseline, women had a mean endometrial thickness of 3.3 mm, which had significantly thickened to a mean of 5.3 mm by 24 weeks (P < 0.001). By 48 weeks, there was significantly greater increase in endometrial thickness from baseline in those women who displayed inadequate endometrial opposition, compared with those women who had adequate endometrial opposition (P= 0.004). At 24 weeks, 48% of women had remained entirely amenorrhoeic. By the end of the study, 35% of women had been entirely amenorrhoeic and 50% had had either no bleeding or spotting alone. The number of bleeding episodes did not reduce with time.

CONCLUSIONS

The dose of natural progesterone cream in this study was insufficient to fully attenuate the mitogenic effect of oestrogen on the endometrium. We would not recommend this combination of hormones to be used by postmenopausal women.

Effects and side-effects of 2% progesterone cream on the skin of peri- and postmenopausal women: results from a double-blind, vehicle-controlled, randomized study

BACKGROUND

For many years topical progesterone has been prescribed by gynaecologists as an antiageing and skin-firming treatment, without any clinical scientific evidence of its effects, tolerability and safety when applied to skin.

OBJECTIVES

To evaluate the influence of 2% progesterone cream on function and texture of the skin in peri- and postmenopausal women.

METHODS

A double-blind, randomized, vehicle-controlled study was conducted in 40 subjects. Objective methods for measuring skin elasticity, epidermal hydration and skin surface lipids, clinical monitoring and self-assessment, and determination of blood hormone levels (luteinizing hormone, follicle-stimulating hormone, oestrogen and progesterone) were used to determine effects and side-effects of this treatment at four visits over a 16-week period.

RESULTS

The study demonstrated a significant (P < or = 0.05) increase of the elastic skin properties in the treatment group, as demonstrated by objective measurements of three skin elasticity parameters, whereas in the control group no such effect was observed. This effect in the treatment group was further paralleled by the results of the clinical monitoring, where the 2% progesterone cream yielded consistent superiority over vehicle in counteracting different signs of ageing in the skin of peri- and postmenopausal women. Clinical monitoring showed a greater reduction in wrinkle counts (29.10% vs. 16.50%) and wrinkle depth (9.72% vs. 7.35%) around the right eye, a greater decrease in nasolabial wrinkle depth (9.72% vs. 6.62%) and a significantly higher (P < 0.05) increase in skin firmness (23.61% vs. 13.24%) in the treatment group. Epidermal hydration and skin surface lipids did not change significantly in either group during the study. Progesterone was well absorbed in the systemic circulation: mean blood levels rose minimally, but statistically significantly (P = 0.001), by 0.53 ng mL(-1). No serious side-effects of the treatment were observed.

CONCLUSIONS

The results of this study demonstrate that topical 2% progesterone acts primarily in increasing elasticity and firmness in the skin of peri- and postmenopausal women. These effects in combination with good tolerability make progesterone a possible treatment agent for slowing down the ageing process of female skin after onset of the menopause.

Transdermal progesterone creams for postmenopausal women: more hype than hope?

Various claims have been made about the benefits of transdermal progesterone creams for relieving symptoms of menopause. Peer-reviewed articles have reported that the creams can raise plasma progesterone levels slightly, but have no effect on vasomotor, psychosexual or mood symptoms, bone metabolism or plasma lipid levels. Currently available progesterone creams can not be recommended for treatment of symptoms associated with menopause.

Percutaneous administration of progesterone: blood levels and endometrial protection

There is controversy about the beneficial effects of topical progesterone creams used by postmenopausal women. A major concern is that serum progesterone levels achieved with progesterone creams are too low to have a secretory effect on the endometrium. However, antiproliferative effects on the endometrium have been demonstrated with progesterone creams when circulating levels of progesterone are low. Thus, effects of topical progesterone creams on the endometrium should not be based on serum progesterone levels, but on histologic examination of the endometrium. Despite the low serum progesterone levels achieved with the creams, salivary progesterone levels are very high, indicating that progesterone levels in serum do not necessarily reflect those in tissues. The mechanism by which the serum progesterone levels remain low is not known. However, one explanation is that after absorption through the skin, the lipophilic ingredients of creams, including progesterone, may have a preference for saturating the fatty layer below the dermis. Because there appears to be rapid uptake and release of steroids by red blood cells passing through capillaries, these cells may play an important role in transporting progesterone to salivary glands and other tissues. In contrast to progesterone creams, progesterone gels are water-soluble and appear to enter the microcirculation rapidly, thus giving rise to elevated serum progesterone levels with progesterone doses comparable to those used in creams.

Hormone replacement therapy: current controversies

Postmenopausal hormonal therapy is used to manage the climacteric symptoms that impair the quality of life of a substantial number of women. The difficulty is achieving the desired effects with minimal side-effects and no adverse health risks. Fundamental to this is understanding the physiology of oestrogen in women and the metabolism of the therapeutic compounds. Although the effects of oral oestrogen therapy have been studied extensively, there is insufficient evidence to assess adequately the independent effects of progestin use, other oestrogen compounds, differing doses and duration of treatment. We have reviewed some basic concepts of oestrogen physiology and how these relate to exogenous oestrogen administration, the risks of greatest concern, and the role of androgens and newer treatment alternatives.

Transdermal progesterone and its effect on vasomotor symptoms, blood lipid levels, bone metabolic markers, moods, and quality of life for postmenopausal women

OBJECTIVE

To determine whether transdermal progesterone cream has any effect on vasomotor symptoms, mood, sexual response, cardiovascular lipid levels, or bone mineral metabolic markers.

DESIGN

A parallel, double-blind, randomized, placebo-controlled trial comparing the effect of a transdermal cream containing a progesterone (32 mg daily) with a placebo cream. Eighty postmenopausal women in the Menopause Centre at the Royal Hospital for Women, Sydney, were randomly allocated to receive either the progesterone cream or the placebo. They were evaluated using the Greene Climacteric Scale and the Menopause Quality of Life Questionnaire, as well as blood analysis for lipids and bone markers over a period of 12 weeks. Women were prescribed a cream containing either progesterone at 32 mg daily or a placebo cream for a period of 12 weeks.

RESULTS

There was no detectable change in vasomotor symptoms, mood characteristics, or sexual feelings, nor was there any change in blood lipid levels or in bone metabolic markers, despite a slight elevation of blood progesterone levels.

CONCLUSION

The use of the transdermal route to administer progesterone at 32 mg daily does not seem to allow sufficient hormone to enter the body to achieve a biological effect on lipid levels, bone mineral metabolic markers, vasomotor symptoms, or moods.

Caution on the use of saliva measurements to monitor absorption of progesterone from transdermal creams in postmenopausal women

OBJECTIVES

To determine the levels of progesterone in plasma, red cells and saliva as well as pregnanediol-3-glucuronide excretion in postmenopausal women using transdermal progesterone creams.

METHODS

A double-blind placebo controlled study was carried out using 24 postmenopausal women. Creams (placebo, 20 or 40 mg progesterone/g) were applied twice daily for 3 weeks followed by 1 week without before a further 3-week treatment. Morning samples were collected at 0, 1, 3, 4, 7 and 8 weeks for analysis.

RESULTS

There were small increases in plasma progesterone levels and pregnanediol-3-glucuronide excretion compared to the placebo group and red cell progesterone levels never exceeded plasma levels during progesterone cream use. Saliva progesterone levels were very high and variable in the progesterone cream groups compared to the placebo group and presented a paradox to the usual relationship observed between plasma and saliva progesterone in premenopausal women.

CONCLUSION

The absorption of progesterone from transdermal creams is low and we caution against the use of saliva measurements to monitor progesterone absorption. The low systemic absorption of progesterone may not be due to peripheral conversion by 5 alpha-reductase(s). We also conclude that the low level of progesterone associated with red cells suggests they are not important in the delivery of progesterone to target tissues.

Herbs, menopause, and dialysis

Women with chronic kidney disease (CKD) are at increased risk for menstrual disorders, early menopause, and osteoporosis, and rarely discuss gynecologic and reproductive issues with their nephrologist. Various complementary and alternative medicine (CAM) products are of interest to women with end-stage renal disease (ESRD) who have these disorders. However, very little is known about the specifics of using herbal medicines in patients on chronic dialysis, resulting in numerous problems when patients and providers try to ascertain the safety and efficacy of these products. This article reviews evidence regarding the safety and efficacy of black cohosh, ginseng, chastetree, dong quai, evening primrose oil, soy products, and the so-called natural hormones. Pharmacologic parameters important to evaluating the quality of botanical products are discussed, along with recommendations and information resources.

Natural vaginal progesterone is associated with minimal psychological side effects: a preliminary study

The objective of this study was to evaluate the psychological side effects of a transvaginal natural progesterone gel in hormone replacement therapy (HRT). This 3-month preliminary study was part of a multicenter study previously performed in our center. We enrolled 49 women (ages 18-45 years) with hypothalamic amenorrhea (HA) (n = 40) and premature ovarian failure (POF) (n = 9). Estrogenized patients applied vaginal progesterone gel (4% or 8%) every other day for six doses per month. The Hopkins Symptom Checklist (HSCL), a psychometric profile test, was administered at baseline, day 13 of cycle 2, day 24 of cycle 2, and day 24 of cycle 3. Application of the progesterone gel caused no significant change in HSCL total scores or individual symptom scores for somatization, obsession-compulsion, interpersonal sensitivity, depression, and anxiety. Natural vaginal progesterone gel can be an effective alternative to oral progesterone for women on HRT.

Thiolated polymers: development and evaluation of transdermal delivery systems for progesterone

PURPOSE

To evaluate the possible use of polycarbophil-cysteine (PCP-Cys) as polymeric matrix for transdermal progesterone application.

METHODS

Thiolated polycarbophil was synthesised by the covalent attachment of cysteine to the basis polymer. The adhesive properties of PCP-Cys in comparison to polyvinylpyrrolidone/hydroxypropylmethylcellulose (PVP/HPMC) and polyvinylpyrrolidone/polyvinylalcohol (PVP/PVA) were investigated by testing the total work of adhesion (TWA) on porcine skin. Release studies in Franz diffusion cells and standard in vitro permeation experiments with porcine skin were performed analysing the progesterone content by high-performance liquid chromatography.

RESULTS

Films based on PCP-Cys displayed very high cohesive properties due to the formation of interchain disulfide bonds. The TWA of the thiolated polymer on porcine skin was significantly (P <0.05) the highest. In addition progesterone permeation was also the highest from PCP-Cys compared with PVP/HPMC and PVP/PVA within 24 hours.

CONCLUSION

PCP-Cys--a partly thiolated polymer--might be a novel polymer matrix for transdermal progesterone delivery with excellent adhesiveness on porcine skin.

Effect of sequential transdermal progesterone cream on endometrium, bleeding pattern, and plasma progesterone and salivary progesterone levels in postmenopausal women

BACKGROUND

Transdermal progesterone is being used in some countries as a purported treatment for menopausal symptoms, either alone or prescribed in conjunction with estrogen, but little information exists regarding the biological activity and effectiveness of this method of delivery of progesterone in protecting the endometrium from excess proliferation. This study was designed to evaluate the use of sequential transdermal progesterone. End-points evaluated included endometrial cellular response and bleeding pattern as well as plasma hormone levels and salivary progesterone estimations.

METHOD

Twenty-seven postmenopausal women were treated with continuous transdermal estrogen (28-day cycle) and a cream containing 16, 32 or 64 mg of progesterone in each 4-cm extrusion from a tube of Pro-Feme administered daily in a sequential (days 15-28 of cycle) regimen. Blood and endometrial samples were analyzed for progesterone response prior to therapy, after the first 14 days of unopposed transdermal estrogen and following 14 days of transdermal progesterone. Saliva samples were taken during the last 14 days of the 84-day study, when the final progesterone cream therapy was being applied.

RESULTS

Hormone assay indicated that physiological levels of estradiol were achieved, but progesterone levels were insufficient to induce any detectable change in the endometrium. Only one patient experienced bleeding during the study period. Levels of salivary progesterone were so variable as to be considered completely unreliable in determining the potential influence on biological activity.

INTERPRETATION

Pro-Feme transdermal progesterone administered in a 16-, 32- or 64-mg daily dose for 14 days in a sequential regimen does not appear to be effective in inducing a secretory change in a proliferative endometrium. Salivary progesterone levels were not of value in managing the therapy of postmenopausal women.