polyestriol phosphate polyestriol phosphate polyestriol phosphate (pe3p, sep), sold under the brand names gynäsan, klimadurin, and triodurin, is an estrogen medication which was previously used in menopausal hormone therapy (i.e., to treat menopausal symptoms in postmenopausal women) and is no longer available. not to be confused with polyestradiol phosphate. polyestriol phosphateskeletal structure of polyestriol phosphate (top) and ball-and-stick model of estriol phosphate (one monomer of polyestriol phosphate) (bottom)clinical datatrade namesgynäsan, klimadurin, triodurinother namespe3p; sep; poly(estriol phosphate); estriol phosphate polymer; estriol polymer with phosphoric acidroutes ofadministrationintramuscular injectiondrug classestrogen; estrogen esterlegal statuslegal status in general: ℞ (prescription only) pharmacokinetic databioavailabilityim: highmetabolitesestriol, phosphoric acid, and metabolites of estriolexcretionurine (as conjugates)identifiers iupac name estra-1,3,5(10)-triene-3,16α,17β-triol, polymer with phosphoric acid cas number37452-43-0uniih4bf1s56xcchemical and physical dataformula(c18h23o5p)n(n = variable)molar masspolymer: variablerepeat unit: 350.346 g/mol medical uses pe3p has been used at a dosage of 40 to 80 mg by intramuscular injection once every 4 to 8 weeks in menopausal hormone therapy. available forms pe3p has been available in the form of ampoules containing 50 to 80 mg in 1 or 2 ml aqueous solution. pharmacology pe3p is similar to polyestradiol phosphate (pep), and is, likewise, an estrogen ester – specifically, an ester and prodrug of estriol – in the form of a polymer with phosphate linkers. when adjusted for differences in molecular weight, pe3p contains the equivalent of about 80% of the amount of estriol. as such, 40 mg pe3p corresponds to about 32 mg estriol. doses of pe3p of 10 mg or more have an extended duration of action. a single intramuscular injection of 80 mg pe3p has a duration of about 1 month and of 80 mg about 2 months. the effects of pe3p on the vagina, uterus, pregnancy, prostate gland, coagulation, and fibrinolysis, as well as on mammary and endometrial cancer risk, have been studied. the endometrial proliferation dose of pe3p over 14 days in women is 40 to 60 mg by intramuscular injection. potencies and durations of natural estrogens by intramuscular injection estrogenformdose (mg)duration by dose (mg) epdcicd estradiolaq. soln. ?–<1 d oil soln.40–60–1–2 ≈ 1–2 d aq. susp. ?3.50.5–2 ≈ 2–7 d; 3.5 ≈ >5 d microsph. ?–1 ≈ 30 d estradiol benzoateoil soln.25–35–1.66 ≈ 2–3 d; 5 ≈ 3–6 d aq. susp.20–10 ≈ 16–21 d emulsion ?–10 ≈ 14–21 d estradiol dipropionateoil soln.25–30–5 ≈ 5–8 d estradiol valerateoil soln.20–3055 ≈ 7–8 d; 10 ≈ 10–14 d;40 ≈ 14–21 d; 100 ≈ 21–28 d estradiol benz. butyrateoil soln. ?1010 ≈ 21 d estradiol cypionateoil soln.20–30–5 ≈ 11–14 d aq. susp. ?55 ≈ 14–24 d estradiol enanthateoil soln. ?5–1010 ≈ 20–30 d estradiol dienanthateoil soln. ?–7.5 ≈ >40 d estradiol undecylateoil soln. ?–10–20 ≈ 40–60 d;25–50 ≈ 60–120 d polyestradiol phosphateaq. soln.40–60–40 ≈ 30 d; 80 ≈ 60 d;160 ≈ 120 d estroneoil soln. ?–1–2 ≈ 2–3 d aq. susp. ?–0.1–2 ≈ 2–7 d estrioloil soln. ?–1–2 ≈ 1–4 d polyestriol phosphateaq. soln. ?–50 ≈ 30 d; 80 ≈ 60 d notes and sources notes: all aqueous suspensions are of microcrystalline particle size. estradiol production during the menstrual cycle is 30–640 µg/d (6.4–8.6 mg total per month or cycle). the vaginal epithelium maturation dosage of estradiol benzoate or estradiol valerate has been reported as 5 to 7 mg/week. an effective ovulation-inhibiting dose of estradiol undecylate is 20–30 mg/month. sources: see template. chemistry