Testosterone

Absorption

A single 100mg topical dose of testosterone has an AUC of 10425±5521ng*h/dL and a Cmax of 573±284ng/dL. Testosterone is approximately 10% bioavailable topically.

Toxicity

Data regarding an overdose with a topical testosterone product is not readily available. In the case of overdose with an injectable product, patients may present with a cerebrovascular event. Treat overdoses by stopping testosterone products, washing off any topical products with soap and water, and initiating symptomatic and supportive treatments.

Description

Testosterone (Item No.15645) is an analytical reference material categorized as an anabolic androgenic steroid. Testosterone is an endogenous metabolite of androstenedione (Item Nos. ISO60161 | 15874) and estradiol (Item Nos. ISO60155 | 10006315). Anabolic steroids, including testosterone, have been used to enhance physical performance in athletes. Testosterone is regulated as a Schedule III compound in the United States. This product is intended for research and forensic applications.

Description

Men who complain of irritability, fatigue, and loss of libido—characteristics of andropause, a male version of menopause—are increasingly turning to testosterone replacement therapy. First reported in the mid-40s, research on this little known condition is intensifying with clinical and drug trials in progress.

Description

Testosterone (CRM) (Item No. ISO60154) is a certified reference material categorized as an anabolic androgenic steroid. Testosterone is an endogenous metabolite of androstenedione (Item Nos. ISO60161 | 15874) and estradiol (Item Nos. ISO60155 | 10006315). Anabolic steroids, including testosterone, have been used to enhance physical performance in athletes. Testosterone is regulated as a Schedule III compound in the United States. This product is intended for research and forensic applications.

Chemical properties

white crystalline odourless solid

The Uses of Testosterone

Secreted by the testis and is converted to dihydrotestosterone in the target tissue where is appears to mediate many of the biological actions of testosterone. CONTROLLED SUBSTANC

The Uses of Testosterone

androgen, antineoplastic

The Uses of Testosterone

Testosterone, Principal hormone of the testes, produced by the interstitial cells. Major circulating androgen; converted by 5α-reductase in androgen-dependent target tissues to 5α-dehydrotestosterone which is required for normal male sexual differentiation. Also converted by aromatization to Estradiol. Testerone is a controlled substance (anabolic steroid). Androgen.

The Uses of Testosterone

Rivastigmine metabolite

The Uses of Testosterone

Testosterone secreted by the testis is converted to dihydrotestosterone in the target tissues where it appears to mediate many of the biological actions of testosterone. Androgens direct the development of the male phenotype during embryogenesis and at puberty.

Background

Testosterone is a steroid sex hormone indicated to treat primary hypogonadism and hypogonadotropic hypogonadism. Testosterone antagonizes the androgen receptor to induce gene expression that causes the growth and development of masculine sex organs and secondary sexual characteristics.
Testosterone was isolated from samples and also synthesized in 1935.

Indications

Testosterone is indicated to treat primary hypogonadism and hypogonadotropic hypogonadism.

Definition

ChEBI: An androstanoid having 17beta-hydroxy and 3-oxo groups, together with unsaturation at C-41C-5..

General Description

Testosterone, 17β-hydroxyandrost-4-en-3-one, is a naturally occurring androgen in men. Inwomen, it mainly serves as a biosynthetic precursor to estradiolbut also has other hormonal effects. It is rapidly metabolizedto relatively inactive 17-ones, however,preventing significant oral activity. Testosterone is availablein a transdermal delivery system (patch), a gel formulation, abuccal system, and as implantable pellets.

Hazard

A confirmed carcinogen.

Health Hazard

Controls secondary male sex characteristics Maintains functional competence of male reproductive ducts and glands
Increases protein anabolism; maintains spermatogenesis; inhibits follotropin
Increases male sex behavior; increases closure of epiphyseal plates

Biological Activity

Endogenous androgen receptor agonist.

Biochem/physiol Actions

Testosterone secreted by the testis is converted to dihydrotestosterone in the target tissues where it appears to mediate many of the biological actions of testosterone. Androgens direct the development of the male phenotype during embryogenesis and at puberty.

Pharmacokinetics

Testosterone antagonizes the androgen receptor to induce gene expression that causes the growth and development of masculine sex organs and secondary sexual characteristics. The duration of action of testosterone is variable from patient to patient with a half life of 10-100 minutes. The therapeutic index is wide considering the normal testosterone levels in an adult man range from 300-1000ng/dL. Counsel patients regarding the risk of secondary exposure of testosterone topical products to children.

Safety Profile

Confirmed carcinogen with experimental neoplastigenic and teratogenic data. Poison by intraperitoneal route. Human teratogenic effects by unspecified route: developmental abnormalities of the urogenital system. Experimental reproductive effects. Human mutation data reported. Workers engaged in manufacture and packagmg have shown effects from this hormone, e.g., enlargement of the breasts in male workers. A promoter. When heated to decomposition it emits acrid smoke and irritating fumes. Used as a drug for the treatment of hypogonadism and metastatic breast cancer.

Synthesis

Testosterone, 17|?-hydroxyandrost-4-ene-3-one (29.1.5), is made in a number of ways from different substances, including cholesterol, although it is most often made from androstenolone acetate. In order to do this, the keto-group at C17 of the steroid system of androstenolone acetate is reduced to a hydroxyl group by either sodium borohydride, lithium aluminum hydride, or hydrogen over Raney nickel, all of which result in a 17|?-hydroxy compound. In the given example, reduction by sodium borohydride or hydrogen over Raney nickel leads to the formation of 3|?-acetoxy-5-androsten-17|?-ol (29.1.1). The hydroxyl group resulting from reduction then undergoes acylation by benzoyl chloride in pyridine, which forms a diester (29.1.2). After that, taking into consideration the differences in the acidic region of the two ester groups present in the molecule as well as the long-known fact that 17-hydroxy-group ester derivatives are harder to hydrolyze than 3-hydroxy-group ester derivatives, the acetyl protection of the hydroxyl group at C3 is removed by selective hydrolysis using potassium hydroxide in ethanol, and the resulting alcohol (29.1.3) is oxidized to a ketone (29.1.4) by aluminum isopropylate in the presence of cyclohexanone as a hydrogen acceptor, during which isomerization of the double bond from position C5¨CC6 to C4¨CC5 simultaneously takes place. Subsequent hydrolysis of the remaining ester region of the molecule using an alkali gives the desired testosterone (29.1.5) . When necessary to convert this into the corresponding ester (propionate, enantate, cypionate, and a few other testosterone esters), the necessary acylation can be accomplished.

Metabolism

Testosterone is metabolized to 17-keto steroids through two different pathways. The major active metabolites are estradiol and dihydrotestosterone (DHT).
Testosterone can be hydroxylated at a number of positions by CYP3A4, CYP2B6, CYP2C9, and CYP2C19; glucuronidated by UGT2B17; sulfated; converted to estradiol by aromatase; converted to dihydrotestosterone (DHT) by 5α-reductase; metabolized to androstenedione by CYP3A4, CYP2C9, and CYP2C19; or converted to DHT glucuronide.
Androstenedione undergoes metabolism by aromatase to form estrone, which undergoes a reversible reaction to form estradiol. Androstenedione can also be converted to 5α-androstanedione by 5α-reductase, which can be further metabolized to 5α-androsterone.
DHT can be glucuronidated or sulfated, or metabolized to 5α-androstanediol, androstane-3α,17β-diol, or androstane-3β,17β-diol. DHT can also be reversibly converted to 5α-androstanedione.

Purification Methods

Crystallise testosterone from aqueous acetone, hexane or isoPrOH. The long needles that separated from EtOH/AcOH were used for X-ray crystallography [Roberts et al. J Chem Soc Perkin Trans II 1978 1973.] The acetate [1045-69-8] crystallises from MeOH or aqueous Me2CO, with m 140-141o and [] D 20 +87.8o (c 1, EtOH). [Ruzicka et al. Helv Chim Acta 18 1478 1935 and 19 99, 842 1936, Beilstein 8 IV 974.]