Estradiol valerate

Absorption

IM Injection: When conjugated with aryl and alkyl groups for parenteral administration, the rate of absorption of oily preparations is slowed with a prolonged duration of action, such that a single intramuscular injection of estradiol valerate or estradiol cypionate is absorbed over several weeks .
Natazia: After oral administration of estradiol valerate, cleavage to 17β-estradiol and valeric acid takes place during absorption by the intestinal mucosa or in the course of the first liver passage. This gives rise to estradiol and its metabolites, estrone and other metabolites. Maximum serum estradiol concentrations of 73.3 pg/mL are reached at a median of approximately 6 hours (range: 1.5–12 hours) and the area under the estradiol concentration curve [AUC(0–24h)] was 1301 pg·h/mL after single ingestion of a tablet containing 3 mg estradiol valerate under fasted condition on Day 1 of the 28-day sequential regimen.

Description

Estradiol valerate (EV), sold for use by mouth under the brand name Progynova and for use by injection under the brand names Delestrogen and Progynon Depot among others, is an estrogen medication. In women, it is used in hormone therapy for menopausal symptoms and low estrogen levels, hormone therapy for transgender women, and in hormonal birth control. It is also used in the treatment of prostate cancer in men. The medication is taken by mouth or by injection into muscle or fat once every 1 to 4 weeks.

Chemical properties

White to off-white crystalline powder, odorless. Insoluble in water, easily soluble in ethanol, acetone, chloroform, slightly soluble in vegetable oil.

Originator

Delestrogen,Squibb,US,1954

The Uses of Estradiol valerate

Estradiol valerate is a female hormone (estrogen). It is used to reduce symptoms of menopause which are vaginal dryness, hot flashes, and others. The symptoms of menopause manifest because the body is making less estrogen; with estradiol valerate, these symptoms are brought to the lowest minimum. This medication therapy can also produce enough estrogen in women with ovarian failure, hypogonadism and can be used by men to treat prostate cancer (palliation only).

Background

Estradiol Valerate (also known as E2V) is a pro-drug ester of Estradiol, a naturally occurring hormone that circulates endogenously within the human body. Estradiol is the most potent form of all mammalian estrogenic steroids and acts as the major female sex hormone. As a pro-drug of estradiol, estradiol acetate therefore has the same downstream effects within the body through binding to the Estrogen Receptor (ER) including ERα and ERβ subtypes, which are located in various tissues including in the breasts, uterus, ovaries, skin, prostate, bone, fat, and brain.
Estradiol is commonly produced with an ester side-chain as endogenous estradiol has very low oral bioavailability on its own (2-10%). First-pass metabolism by the gut and the liver quickly degrades the estradiol molecule before it gets a chance to enter systemic circulation and exert its estrogenic effects . Esterification of estradiol aims to improves absorption and bioavailability after oral administration (such as with Estradiol valerate) or to sustain release from depot intramuscular injections (such as with Estradiol Cypionate) through improved lipophilicity. Following absorption, the esters are cleaved, resulting in the release of endogenous estradiol, or 17β-estradiol. Ester pro-drugs of estradiol are therefore considered to be bioidentical forms of estrogen .
Estradiol valerate is commercially available as an intramuscular injection as the product Delestrogen and is indicated for the treatment of moderate to severe vasomotor symptoms and vulvovaginal atrophy due to menopause, for the treatment of hypoestrogenism due to hypogonadism, castration or primary ovarian failure, and for the treatment of advanced androgen-dependent carcinoma of the prostate (for palliation only). Estradiol valerate is also available in combination with Dienogest as the commercially available product Natazia used for the prevention of pregnancy and for the treatment of heavy menstrual bleeding.
The primary source of estrogen in normally cycling adult women is the ovarian follicle, which secretes 70 to 500 mcg of estradiol daily, depending on the phase of the menstrual cycle. However, after menopause, most endogenous estrogen is produced by conversion of androstenedione, secreted by the adrenal cortex, to estrone by peripheral tissues. Thus, estrone and the sulfate conjugated form, estrone sulfate, are the most abundant circulating estrogens in postmenopausal women . Although circulating estrogens exist in a dynamic equilibrium of metabolic interconversions, estradiol is the principal intracellular human estrogen and is substantially more potent than its metabolites, estrone and estriol at the receptor level. Because of the difference in potency between estradiol and estrone, menopause (and a change in primary hormone from estradiol to estrone) is associated with a number of symptoms associated with this reduction in potency and in estrogenic effects. These include hot flashes, vaginal dryness, mood changes, irregular menses, chills, and sleeping problems. Administration of synthetic and bioidentical forms of estrogen, such as estradiol valerate, has shown to improve these menopausal symptoms.

Indications

Estradiol valerate is commercially available as an intramuscular injection as the product Delestrogen and is indicated for the treatment of moderate to severe vasomotor symptoms and vulvovaginal atrophy due to menopause, for the treatment of hypoestrogenism due to hypogonadism, castration or primary ovarian failure, and for the treatment of advanced androgen-dependent carcinoma of the prostate (for palliation only).
Estradiol valerate is also available in combination with Dienogest as the commercially available product Natazia used for the prevention of pregnancy and for the treatment of heavy menstrual bleeding.

Indications

Estradiol valerate is commercially available as an intramuscular injection as the product Delestrogen and is indicated for the treatment of moderate to severe vasomotor symptoms and vulvovaginal atrophy due to menopause, for the treatment of hypoestrogenism due to hypogonadism, castration or primary ovarian failure, and for the treatment of advanced androgen-dependent carcinoma of the prostate (for palliation only). Estradiol valerate is also available in combination with Dienogest as the commercially available product Natazia used for the prevention of pregnancy and for the treatment of heavy menstrual bleeding.

Definition

ChEBI: Estradiol valerate is a steroid ester. It is the parenterally-administered synthetic valerate ester of estradiol, a steroid sex hormone vital to the maintenance of fertility and secondary sexual characteristics in females.

Manufacturing Process

2.3 parts of estradiol are mixed with 12 parts of pyridine and 10 parts of nvaleric anhydride and the mixture is heated for some time at 115°C in the oil bath. The cooled solution is mixed with 250 parts of water, whereupon an oil separates; this is extracted with ether. The separated ethereal solution is washed successively with N sulfuric acid, water, N sodium carbonate solution and water and then dried. The ether is then removed and the residue purified by distillation in a high vacuum. The estradiol di-n-valerate forms a yellowish oil according to US Patent 2,205,627.
1 part of estradiol-3,17-n-divalerianate (boiling point at 0.01 mm = 220° to 230°C bath temperature; made, e.g., by the action of n-valeric anhydride on a solution of estradiol in pyridine) is mixed with 50 parts of a solution of 0.5% strength of potassium carbonate in methyl alcohol of 95% strength, and the whole is stirred for some time at 20°C. The oily n-di-valerianate passes gradually into solution. The solution is neutralized and the precipitate is produced by the addition of about 200 parts of water. This finely crystalline product is filtered and washed successively with water, dilute sodium carbonate solution and again with water. It may be further purified by crystallization from a mixture of methyl alcohol and water. The estradiol-17- mono-n-valerianate melts at 144° to 145°C according to US Patent 2,233,025.

brand name

Delestrogen (King).

Therapeutic Function

Estrogen

General Description

Estradiol valerate is a synthetic hormone that is extensively metabolized to estradiol and valeric acid before reaching the systemic circulation. It is well suited for treatment of the characteristic symptoms accompanying menopause in women.

Pharmacokinetics

Estrogen mediates its effects across the body through potent agonism of the Estrogen Receptor (ER), which is located in various tissues including in the breasts, uterus, ovaries, skin, prostate, bone, fat, and brain. Estradiol binds to both subtypes of the Estrogen Receptor: Estrogen Receptor Alpha (ERα) and Estrogen Receptor Beta (ERβ). Estradiol also acts as a potent agonist of G Protein-coupled Estrogen Receptor (GPER), which has recently been recognized as a major mediator of estradiol's rapid cellular effects .

Side Effects

As with all pharmaceutical medicines, some unwanted effects can occur from the use of estradiol valerate tablets.
Always consult a physician for medical advice before use.
Common side effects may include: bloating, vomiting, nausea, breast tenderness, headache, weight changes, and mood changes.
More severe side effects may include mental changes, breast lumps, vaginal bleeding, liver damage, increased thirst, and sudden vision loss.

Safety Profile

Suspected carcinogen with carcinogenic and teratogenic data. Experimental reproductive effects. When heated to decomposition it emits acrid smoke and irritating fumes. See also ESTRADIOL.

Metabolism

Exogenous estrogens are metabolized using the same mechanism as endogenous estrogens. Estrogens are partially metabolized by cytochrome P450.