Estradiol undecylenate explained

Estradiol undecylenate (EUe; developmental code name SH-368)^[1] is an estrogen medication and estrogen ester which was never marketed.^[2] It is the C17β undecenoate (undecylenate) ester of estradiol. Following an intramuscular injection, EUe has a very prolonged effect, exceeding that of other estradiol esters like estradiol valerate and estradiol enanthate.^[3] Due to its very long duration of action, EUe releases only subthreshold amounts of estradiol at conventional doses. However, this may still be useful in menopausal hormone therapy.

See also

• Estradiol diundecylenate
• List of estrogen esters § Estradiol esters

Notes and References

1. Book: Unlisted Drugs. 1975. Pharmaceutical Section, Special Libraries Association.. 978-0-913210-02-4. estradiol undecylate [...] Delestrec [...] SQ 9993 [...] estradiol undecylenate [...] SH 368.
2. DE . 1096904 . Estradiol 17-undecenoate . 12 January 1961 . Ringold HJ, Batres E, Rosenkranz G . Svntex S.A. . Estradiol 3,17-diacylates, contg. at least one 17-undecenoyl group, were hydrolyzed selectively in the 3-position by known methods to give the title compds., useful as estrogens, showing protracted activity. Thus, 150 g. undecenoyl chloride was added slowly at max. 40° to 100 g. estradiol in 500 cc. abs. C5H5N, the mixt. kept 15 hrs. at room temp., heated 0.5 hr. on a steam bath, dild. with H2O, extd. with Et2O, the ext. washed with 5% HCl, H2O, and dild. NaHCO3 soln., dried, and concd., the crude diacylate slurried in 100 cc. MeOH, treated 30 hrs. with stirring with a soln. of 36.5 K2CO3 in 500 cc. H2O and 4500 cc. MeOH, the mixt. neutralized, dild. with 1200 cc. H2O, cooled, extd. with Et2O, and the ext. washed, dried, and concd. to give estradiol 17-undecenoate, m. 105-6° (Et2O-MeOH), [α]D 42°..
3. Book: Harper NJ . Drug Latentiation . Jucker E . Fortschritte der Arzneimittelforschung / Progress in Drug Research / Progrès des recherches pharmaceutiques. https://books.google.com/books?id=AYH1BwAAQBAJ&pg=PA243. 1962. Birkhäuser. 978-3-0348-7044-3. 243–. Retarded estrogens. In animal experiments it has been shown esterification at C-17 results in longer retarding effects than esterification at C-3. The optimal retarding effect (exceeding 29 days) may be obtained with the C-17 oenanthate. However, the effect exceeds the time interval of 28 days normally considered sufficient for the treatment of a female during one period and for this reason the shorter active estradiol-17-valerianate has been introduced. The estradiol undecylenate has a more protracted effect but it releases only subthreshold doses of steroid (advantage may be taken of this for the treatment of menopause)..