Contraceptive efficacy and tolerability with a novel combined contraceptive vaginal ring, NuvaRing

Vaginal ring acceptability: A systematic review and meta-analysis of vaginal ring experiences from around the world

OBJECTIVE

The vaginal ring (ring) is a female-initiated, long-acting drug delivery system for different indications, including HIV prevention. Our aim was to provide evidence for acceptability of the vaginal ring across indications to support dapivirine and multipurpose prevention technology ring introduction and roll out.

STUDY DESIGN

This systematic review and meta-analysis followed PRISMA guidelines. We searched PubMed, Web of Science, Embase, and grey literature for publications reporting favorable ring acceptability and secondary outcomes involving actual ring use (comfort, ease of ring use, ring comfort during sex, expulsions, and vaginal symptoms) or hypothetical acceptability for any indication published January 1, 1970-June 15, 2021. We estimated random-effects pooled prevalence, assessing between-study variation using meta-regression.

RESULTS

Of 2,234 records, we included 123 studies with 40,434 actual and hypothetical ring users. The primary outcome assessment included 50 studies with 60 ring subgroups totaling 19,271 ring users. The favorable acceptability pooled prevalence was 85.6% (95%CI 81.3, 89.0), while hypothetical acceptability among non-ring users was 27.6% (95%CI 17.5, 40.5). In meta-regression, acceptability was higher in menopause (95.4%; 95%CI 88.4, 98.2) compared to contraceptive rings (83.7%; 95%CI 75.6, 89.5). Acceptability was lower in pharmacokinetic studies (50%; 95%CI 22.1, 77.9) compared to RCTs (89.5%; 95%CI 85.8.92.4) and in studies assessing acceptability at ≥12 months (78.5%; 95%CI 66.5, 87.1) versus studies assessing acceptability at <3 months (91.9%; 95%CI 83.7, 96.1). European (90.6%; 95%CI 83.9, 94.7), Asian (97.1%; 95%CI 92.0, 99.0), and multi-region studies (93.5%; 95%CI 84.6, 97.4) reported more favorable acceptability compared to African studies (59.4%; 95%CI 38.3, 77.5). Secondary outcomes were similarly favorable, including ring comfort (92.9%; 95%CI 89.2, 95.4), ease of use (90.9%; 95%CI 86.5, 94.0), and comfort during sex (82.7%; 95%CI 76.4, 87.6). Limitations include inconsistent outcome definitions and unmeasured factors affecting acceptability.

CONCLUSIONS

Women who used vaginal rings reported they were acceptable across indications geographic regions and indications. Policy makers should consider the ring as an important option for pregnancy and HIV prevention drug development.

IMPLICATIONS

This review found favorable acceptability among vaginal ring users across indications and geographic areas, in contrast to low hypothetical acceptability among non-users. Vaginal rings are an important drug delivery system for pregnancy and HIV preventions, and scale-up should plan to address initial hesitancy among new users.

Analysis and new contraception frontiers with combined vaginal rings

Combined vaginal rings (ethinylestradiol (EE)/desogestrel), indicated for contraception, are highly effective, comparable to other combined hormonal contraceptives, such as pills. In addition to this benefit, vaginal rings are easy to use, with a probable lower risk of forgetting, due to their non-daily, monthly schedule. Besides, for users with poor gastric tolerance to oral formulations, they represent a method with safety and comparable extraconceptive benefits. The latest generation rings have a novel polymeric structure, do not need special storage methods and do not generate accelerated initial release of EE, reducing the early increased systemic exposure to the synthetic steroids they contain. This review describes main aspects related to its use, efficacy, and safety for contraceptive purposes.

Novel multipurpose pod-intravaginal ring for the prevention of HIV, HSV, and unintended pregnancy: Pharmacokinetic evaluation in a macaque model

Globally, women bear an uneven burden for sexual HIV acquisition. Results from two clinical trials evaluating intravaginal rings (IVRs) delivering the antiretroviral agent dapivirine have shown that protection from HIV infection can be achieved with this modality, but high adherence is essential. Multipurpose prevention technologies (MPTs) can potentially increase product adherence by offering protection against multiple vaginally transmitted infections and unintended pregnancy. Here we describe a coitally independent, long-acting pod-IVR MPT that could potentially prevent HIV and HSV infection as well as unintended pregnancy. The pharmacokinetics of MPT pod-IVRs delivering tenofovir alafenamide hemifumarate (TAF2) to prevent HIV, acyclovir (ACV) to prevent HSV, and etonogestrel (ENG) in combination with ethinyl estradiol (EE), FDA-approved hormonal contraceptives, were evaluated in pigtailed macaques (N = 6) over 35 days. Pod IVRs were exchanged at 14 days with the only modification being lower ENG release rates in the second IVR. Plasma progesterone was monitored weekly to determine the effect of ENG/EE on menstrual cycle. The mean in vivo release rates (mg d-1) for the two formulations over 30 days ranged as follows: TAF2 0.35-0.40; ACV 0.56-0.70; EE 0.03-0.08; ENG (high releasing) 0.63; and ENG (low releasing) 0.05. Mean peak progesterone levels were 4.4 ± 1.8 ng mL-1 prior to IVR insertion and 0.075 ± 0.064 ng mL-1 for 5 weeks after insertion, suggesting that systemic EE/ENG levels were sufficient to suppress menstruation. The TAF2 and ACV release rates and resulting vaginal tissue drug concentrations (medians: TFV, 2.4 ng mg-1; ACV, 0.2 ng mg-1) may be sufficient to protect against HIV and HSV infection, respectively. This proof of principle study demonstrates that MPT-pod IVRs could serve as a potent biomedical prevention tool to protect women's sexual and reproductive health and may increase adherence to HIV PrEP even among younger high-risk populations.

Effects of a combined oral contraceptive containing 20 mcg of ethinylestradiol and 3 mg of drospirenone on the blood pressure, renin-angiotensin-aldosterone system, insulin resistance, and androgenic profile of healthy young women

Combined oral contraceptives (COCs) may increase the risk for cardiovascular disease depending on the ethynyl estradiol (EE) dose and the androgenicity of the progestogens. Our objective was to evaluate the impact of a COC containing 20 mcg EE + 3 mg drospirenone on blood pressure (BP), renin-angiotensin-aldosterone system, insulin resistance, and androgenic profile of healthy young women. Eighty-one healthy young women aged 30 ± 1 years (case group, n = 49, received COC; control group, n = 32, used no COC) were assessed twice, before and after the 6-month study. Statistical analysis employed the paired t-tests and expressed the data in mean and standard deviation. Results were as follows: no changes in BP or in BMI; a significant increase in aldosterone, plasma renin activity, triglycerides, and total cholesterol levels, but a non-significant increase in HDL and no significant changes in LDL levels (these parameters remained within normal ranges); a significant increase in the HOMA-IR index and a significant decrease in dehydroepiandrosterone sulfate (SDHEA), androstenedione, total testosterone, and free testosterone levels; no significant variations in the control group parameters. An oral contraceptive combination of a low EE dose and an anti-androgenic progestogen does not negatively influence the risk factors for a cardiovascular disease.

Broad counseling for adolescents about combined hormonal contraceptive methods: the choice study

PURPOSE

The Contraceptive Health Research of Informed Choice Experience study involved 11 European countries with the goal of evaluating the influence of counseling on the user's choice among three different types of combined hormonal contraceptive (CHC) administration: pill, transdermal patch, and vaginal ring. Here, we report the results of the youngest age group (age 15-20 years) for Switzerland.

METHODS

A total of 1,032 adolescent women who contemplated a CHC form of contraception were counseled about the three CHCs. Questionnaires were filled out to determine the women's preferred choice before and after counseling, and the reason for their final decision.

RESULTS

After counseling, more than one third of the women decided to use a different contraceptive method than initially intended. The fraction of vaginal ring users increased from 7.5% to 21.8%, and that of patch users from 3.3% to 5.8%. At pre-counseling, 225 women had no preconceived idea about which method to choose. Only 29 women were still undecided post-counseling. The main reasons adolescent women chose the vaginal ring or the patch were the monthly or weekly use and the ease of use.

CONCLUSIONS

Adolescent women's decision about which CHC to use is greatly influenced by counseling that provides balanced information on all CHCs.

Counseling on vaginal delivery of contraceptive hormones: implications for women's body knowledge and sexual health

BACKGROUND

Healthcare providers (HCPs) have an important role in helping women select the contraceptive method that best matches their needs and lifestyle. Recent surveys outline the need of women to be informed about all available choices, including the newest methods (particularly those not requiring daily administration), such as vaginal contraception.

METHODS

The most relevant publications on combined contraceptive vaginal ring are revised in the context of counseling as an opportunity to empower women in term of vaginal health and sexual functioning.

RESULTS

HCPs should explain the main characteristics of the combined contraceptive vaginal ring including the anatomical and physiological implications that make the vagina an ideal route of hormonal administration and the basic notions about functional modifications of the vagina during reproductive life. Clinical data on the vaginal ring should be summarized with regard to efficacy, tolerability, pharmacokinetics, cycle control and user acceptability, including recent findings on extra-contraceptive benefits (also compared to other hormonal contraceptives) on the vaginal flora and on sexual function.

CONCLUSION

Vaginal contraception offers various benefits and should always be discussed during contraceptive counseling. An open dialogue about vaginal contraception will also help enhance body knowledge and sexual health.

Roles of the circulating renin-angiotensin-aldosterone system in human pregnancy

This review describes the changes that occur in circulating renin-angiotensin-aldosterone system (RAAS) components in human pregnancy. These changes depend on endocrine secretions from the ovary and possibly the placenta and decidua. Not only do these hormonal secretions directly contribute to the increase in RAAS levels, they also cause physiological changes within the cardiovascular system and the kidney, which, in turn, induce reflex release of renal renin. High levels of ANG II play a critical role in maintaining circulating blood volume, blood pressure, and uteroplacental blood flow through interactions with the ANG II type I receptor and through increased production of downstream peptides acting on a changing ANG receptor phenotype. The increase in ANG II early in gestation is driven by estrogen-induced increments in angiotensinogen (AGT) levels, so there cannot be negative feedback leading to reduced ANG II production. AGT can exist in various forms in terms of redox state or complexed with other proteins as polymers; these affect the ability of renin to cleave ANG I from AGT. Thus, during pregnancy the rate of ANG I production varies not only because levels of renin change in response to homeostatic demand but also because AGT changes not only in concentration but in form. Activation of the circulating and intrarenal RAASs is essential for normal pregnancy outcome subserving the increased demand for salt and, hence, water during pregnancy. Thus, the complex integration of the secretions and actions of the circulating maternal renin-angiotensin system in pregnancy plays a key role in pregnancy outcome.

Pharmacokinetics of a multipurpose pod-intravaginal ring simultaneously delivering five drugs in an ovine model

Multipurpose technologies that simultaneously protect from sexually transmitted infections and unintended pregnancy are urgently needed. Pod-intravaginal rings (IVRs) formulated with the antiretroviral agents (ARVs) tenofovir, nevirapine, and saquinavir and the contraceptives etonogestrel and estradiol were evaluated in sheep. Steady-state concentrations were maintained for 28 days with controlled, sustained delivery. This proof-of-principle study demonstrates that pod IVRs can deliver three ARVs from different mechanistic classes and a progestin-estrogen combination over the wide range needed for putative preventative efficacy.

Reproductive and contraceptive issues in chronically ill adolescents

OBJECTIVES

To address reproductive and contraceptive issues in adolescent girls with chronic medical conditions in order to assist health-care providers when they counsel teenagers about contraceptive methods.

METHODS

The review is based on a literature search in Medline (1973-2010) about specific contraceptive use by adolescents with obesity, endocrine, cardiovascular, haematologic, oncologic, neurological, psychiatric, gastrointestinal, hepatobiliary, autoimmune, renal, pulmonary conditions and disabilities. The latest recommendations from the World Health Organisation for adolescents are also added. Contraceptive methods studied were combined hormonal contraceptives, progestogen-only contraceptives, and intrauterine contraceptives.

RESULTS

Adolescents are eligible to use any method of contraception. Contraceptive choices of chronically ill adolescents have changed over time. Given new developments in the field of adolescent sexual and reproductive health care, safe and effective forms of contraception are available for almost every adolescent with a chronic condition. When selecting a method, the nature of the medical illness and the expressed desires of the teenager must be taken into account.

CONCLUSIONS

Adolescents, including those with chronic conditions, are sexual beings; they are entitled to sexual and reproductive health care. Decisions on appropriate contraception must be based upon informed choice, after adequate sexual health education.

Effect of missed combined hormonal contraceptives on contraceptive effectiveness: a systematic review

BACKGROUND

Combined hormonal contraceptives (CHCs) are popular methods of reversible contraception in the United States, but adherence remains an issue as reflected in their lower rates of typical use effectiveness. The objective of this systematic review was to evaluate evidence on the effect of missed CHCs on pregnancy rates as well as surrogate measures of contraceptive effectiveness (e.g., ovulation, follicular development, changes in hormone levels, cervical mucus quality).

STUDY DESIGN

We searched the PubMed database for peer-reviewed articles published in any language from database inception through April 2012. We included studies that examined measures of contraceptive effectiveness during cycles with extended hormone-free intervals or nonadherence (e.g., omission of pills, delayed patch replacement) on days not adjacent to the hormone-free interval. We used standard abstract forms and grading systems to summarize and assess the quality of the evidence.

RESULTS

The search strategy identified 1387 articles, of which 26 met our study selection criteria. There is wide variability in the amount of follicular development and risk of ovulation among women who extended the pill-free interval to 8-14 days; in general, the risk of ovulation was low, and among women who did ovulate, cycles were usually abnormal (i.e., low progesterone levels, small follicles and/or poor cervical mucus) (Level I, good, indirect to Level II-3, fair, indirect). Studies of women who missed one to four consecutive pills or 1-3 consecutive days of delay before patch replacement at times other than adjacent to the hormone-free interval reported little follicular activity and low risk of ovulation (Level I, fair, indirect to Level II-3, poor, indirect). Studies comparing 30 mcg versus 20 mcg mc ethinyl estradiol pills showed more follicular activity when 20 mcg ethinyl estradiol pills were missed (Level I, good, indirect).

CONCLUSION

Most of the studies in this evidence base relied on surrogate measures of pregnancy risk and ranged in quality. For studies providing indirect evidence on the effects of missed CHCs, it is unclear how differences in surrogate measures correspond to pregnancy risk. Fewer studies examined the transdermal patch and vaginal ring than combined oral contraceptives.

Segmented polyurethane intravaginal rings for the sustained combined delivery of antiretroviral agents dapivirine and tenofovir

Dual segment polyurethane intravaginal rings (IVRs) were fabricated to enable sustained release of antiretroviral agents dapivirine and tenofovir to prevent the male to female sexual transmission of the human immunodeficiency virus. Due to the contrasting hydrophilicity of the two drugs, dapivirine and tenofovir were separately formulated into polymers with matching hydrophilicity via solvent casting and hot melt extrusion. The resultant drug loaded rods were then joined together to form dual segment IVRs. Compression testing of the IVRs revealed that they are mechanically comparable to the widely accepted NuvaRing IVR. Physical characterization of the individual IVR segments using wide angle X-ray scattering and differential scanning calorimetry determined that dapivirine and tenofovir are amorphous and crystalline within their polymeric segments, respectively. In vitro release of tenofovir from the dual segment IVR was sustained over 30 days while dapivirine exhibited linear release over the time period. A 90 day accelerated stability study confirmed that dapivirine and tenofovir are stable in the IVR formulation. Altogether, these results suggest that multisegment polyurethane IVRs are an attractive formulation for the sustained vaginal delivery of drugs with contrasting hydrophilicity such as dapivirine and tenofovir.

Drug delivery for in vitro fertilization: rationale, current strategies and challenges

In vitro fertilization has experienced phenomenal progress in the last thirty years and awaits the additional refinement and enhancement of medication delivery systems. Opportunity exists for the novel delivery of gonadotropins, progesterone and other adjuvants. This review highlights the rationale for various medications, present delivery methods and introduces the status of novel ideas and possibilities.

Evaluation of menstrual bleeding patterns: a new proposal for a universal guideline based on the analysis of more than 4500 bleeding diaries

OBJECTIVE

To develop a universal guideline allowing the comparison of interventions like oral contraceptives and hormone replacement therapy with an impact on menstrual bleeding pattern.

METHODS

Literature analysis and cluster analysis of 4612 bleeding diaries.

RESULTS

We summarized key definitions needed for the evaluation of menstrual bleeding patterns from the literature. We developed a methodology to systematically evaluate menstrual bleeding patterns that distinguishes between cyclical and continuous hormonal regimens.

CONCLUSION

This universal guideline can be applied to all prospective clinical studies that affect menstrual bleeding patterns. It allows regulatory agencies and prescribing physicians to make meaningful comparisons of different products.

Cycle control, tolerability, efficacy and acceptability of the vaginal contraceptive ring, NuvaRing®: Results of clinical experience in Germany

OBJECTIVES

To investigate the real-life clinical experience of NuvaRing users in Germany.

METHODS

An open-label, prospective, uncontrolled, non-randomized, multicentre postmarketing surveillance study was conducted by 1204 gynaecologists amongst 5823 women requesting contraception. The women underwent routine examinations and contraceptive counselling, and were assessed after three and six cycles of NuvaRing use.

RESULTS

Good cycle control was observed and there was a reduction in cycle irregularity and inter-menstrual bleeding, bleeding duration and intensity, and dysmenorrhoea. NuvaRing was well tolerated, and had no significant effect on body weight or blood pressure. Nine women became pregnant unintentionally (two had conceived before they started to use NuvaRing, three due to non-compliance, one because of repeated ring expulsion/loss and three during treatment in spite of having applied this latter as instructed). Most women expressed their satisfaction with NuvaRing; 82% were 'very satisfied/ satisfied', 72% planned to continue using it and 82% would recommend it to others. More than 90% of women found NuvaRing 'without problems/easy' to insert and to remove, and more than 80% of the women and their partners were not disturbed by its presence during intercourse.

CONCLUSION

NuvaRing is a highly effective and acceptable method of once-monthly contraception that is safe and well tolerated.

The combined contraceptive vaginal device (NuvaRing®): A comprehensive review

OBJECTIVES

The aim of this study is to review the development of NuvaRing over the past decade to illustrate its use-effectiveness and acceptance as an alternative contraceptive option for women.

METHODS

The data were extracted from the literature using computerised MEDLINE system. NuvaRing is a new combined hormonal contraceptive vaginal ring made of ethylene-vinyl-acetate copolymer, releasing 120 microg etonorgestrel and 15 microg ethinyloestradiol per day. This ring is inserted on any day from day 1 to day 5 of a menstrual cycle for 21 days, thereafter removed for 7 days ring-free period and discarded.

RESULTS

Complete inhibition of ovulation is observed during treatment with this device. Clinical exposure to NuvaRing for 1786 women-years has resulted in 21 pregnancies, giving a Pearl Index of 1.18. Withdrawal bleeding (4.7-5.3 days) is regular (97-99% of cycles) with rare incidence of irregular bleeding (2.6-6.4%). The cycle control is good with the use of this combined contraceptive vaginal ring. NuvaRing is well tolerated and accepted by women as compared to oral pill.

CONCLUSIONS

NuvaRing is an effective vaginal contraceptive option for women. However, further study is needed for monitoring its long-term effectiveness and impact on patient's quality of life since the NuvaRing is marketed in many countries.

Polyurethane intravaginal ring for controlled delivery of dapivirine, a nonnucleoside reverse transcriptase inhibitor of HIV-1

Women-controlled methods for prevention of male-to-female sexual transmission of HIV-1 are urgently needed. Providing inhibitory concentrations of HIV-1 reverse transcriptase inhibitors to impede the replication of the virus in the female genital tissue offers a mechanism for prophylaxis of HIV-1. To this end, an intravaginal ring device that can provide long duration delivery of dapivirine, a nonnucleoside reverse transcriptase inhibitor of HIV-1, was developed utilizing a medical-grade polyether urethane. Monolithic intravaginal rings were fabricated and sustained release with cumulative flux linear with time was demonstrated under sink conditions for a period of 30 days. The release rate was directly proportional to the amount of drug loaded. Another release study conducted for a week utilizing liposome dispersions as sink conditions, to mimic the partitioning of dapivirine into vaginal tissue, also demonstrated release rates constant with time. These results qualify polyether urethanes for development of intravaginal rings for sustained delivery of microbicidal agents.

Non-oral reversible contraceptive methods

There are many contraceptives in the world market today. Knowledge of the vast spectrum of contraceptive methods is essential to the everyday practice of healthcare personnel. Such knowledge translates to improved care and access for women so they can obtain and utilize the appropriate contraception for their individual needs. This is a review of non-oral and nonsurgical contraceptive methods.

Clinical performance and menstrual bleeding patterns with three dosage combinations of a Nestorone progestogen/ethinyl estradiol contraceptive vaginal ring used on a bleeding-signaled regimen

OBJECTIVE

We examined the clinical performance of contraceptive vaginal rings (rings) delivering Nestorone (NES) progestin and ethinyl estradiol (EE). Ring removal times were signaled by menstrual events. Bleeding patterns, adverse events, patterns of use and continuation rates were the principal parameters evaluated.

METHODS

In a two-stage 6-month trial, subjects were randomized to use rings releasing 50 microg/day of NES and either 10 (50/10) or 20 (50/20) microg/day of EE. Subjects were to keep rings continuously in situ until menstrual bleeding or prolonged spotting-signaled removal. Reinsertion was to occur 96 h later. After the randomized stage, an open-label 6-month trial of rings releasing 150 microg/day of NES and 15 microg/day of EE (150/15) began with the same menstrually signaled regimen.

RESULTS

Two-hundred forty-six subjects participated in the trial. Six-month pregnancy rates ranged by ring dose from 1.3 to 3.9 per 100. For each ring dose combination, 6-month continuation rates were above 80 per 100. Bleeding and spotting (B+S) days in women with the 50 microg/day NES rings were similar in number to those experienced by cycling women not using contraception. Nevertheless, in the initial 90 days, fewer B+S days were reported by subjects with the 50/20 ring than by subjects with the 50/10 ring (p < .05). Throughout the trial, subjects using the 150/15 ring reported significantly fewer B+S episodes than did subjects with either 50 microg/day NES ring.

CONCLUSION

Combined contraceptive rings used with a bleeding-signaled regimen led to few terminations attributed to bleeding problems and to acceptable continuation rates. The 150/15 ring appeared to induce fewer bleeding problems than did the lower-dose NES combination rings, but no important difference in 6-month continuation rates among the three doses was noted.

In vivo assessment of NuvaRing® placement

NuvaRing, a combined contraceptive vaginal ring 54 mm in diameter, offers many advantages over oral contraceptives. To better delineate in vivo placement, we performed MRI to confirm its anatomical position. Two healthy users, one nulliparous and one parous, underwent a series of MRI: preinsertion, immediately postinsertion and after ambulation. Three-dimensional imaging of the human vagina demonstrates that in vivo, NuvaRing is located superior to the urogenital diaphragm (UGD), surrounding the cervix. The superior-most aspect of the ring lies behind (posterior) the cervix, at a level superior to the external os. The inferior aspect of the ring also lies in the vaginal canal above the UGD. The entire cervix rests inside the ring. The preambulation image in the nulliparous woman was the only exception. In this case, the upper portion of the ring was at the level of the lower-mid cervix and the lower aspect below the UGD. After ambulation, the ring moved cephalad and surrounded the cervix. In all instances, ambulation resulted in lower aspect of NuvaRing moving away from the introitus. In vivo, NuvaRing is compressed laterally forming a gentle oval in the anterior-posterior direction (5-7 mm longer than wide), an effect that is seen more in nulliparous women.

Contraception for college students

An important issue for human beings is the acquisition of normal sexual health, including the understanding and application of reproductive health when needed. Comprehensive sexuality education is not a topic provided to many children, adolescents, or college students in the United States, however. Students who were sexually active in high school may continue to be at risk for unwanted pregnancies and sexually transmitted diseases in their college life; those who chose abstinence in high school may abandon this concept in college, choosing coital behavior at all levels of university life-freshman through graduate levels. Most American college students are sexually active and many have multiple partners. This article reviews current contraceptive methods available to college students. College health providers and pediatricians are urged to be vigilant about the reproductive health needs of the college students they serve.

Drug delivery systems for oestrogenic hormones and antagonists: the need for selective targeting in estradiol-dependent cancers

The pleiotropic activity of oestrogens and their mechanism of action via their binding to the two oestrogen receptors alpha (ER alpha) and beta (ER beta) subtypes in the different tissues where oestrogens exert their action have been briefly described. The fate of these compounds trapped into different galenic forms is discussed with regard to their therapeutic applications. Firstly, the advantages and disadvantages of the different forms (pills, i.v. forms and transdermal patches) used in contraception are compared. Secondly, the therapeutic use of formulated oestrogens for the post-menopausal hormone replacement therapy (HRT) is analysed through the various results obtained in different trials. The link between HRT and the risks of breast cancer and cardiovascular disease is underlined. Finally, comparing the activity of selective oestrogen receptor modulators such as tamoxifen and pure anti-oestrogens such as RU58668 and ICI182780, we analysed the reasons leading to the need for a tumor targeting of the latters, but not of the former for the treatment of oestrogen-dependent breast cancer. Different injectable and biodegradable formulations, that lead to a remarkable anti-tumor efficiency in xenografts, have been recently developed and we believe that they may represent promising new administration ways of added therapeutic values for anti-oestrogens. Such devices could be extended to the delivery of other anti-cancer drugs with more aggressive activities than anti-oestrogens.