 | |
| Clinical data | |
|---|---|
| Other names | LPP; 17α-Ethynylestr-4-en-17β-ol 17β-(3-phenylpropionate); 19-Nor-17α-pregn-4-en-20-yn-17-ol benzenepropanoate |
| Routes of administration | Intramuscular injection |
| Drug class | Progestogen;Progestin;Progestogen ester |
| Identifiers | |
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| CAS Number | |
| Chemical and physical data | |
| Formula | C29H36O2 |
| Molar mass | 416.605 g·mol−1 |
| 3D model (JSmol) | |
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Lynestrenol phenylpropionate (LPP), also known asethynylestrenol phenylpropionate, is aprogestin and aprogestogen ester which was developed for potential use as aprogestogen-only injectable contraceptive byOrganon but was never marketed.[1][2][3][4][5][6][7][8] It was assessed at doses of 25 to 75 mg in anoil solution once a month byintramuscular injection.[1][4] LPP was associated with high contraceptive failure at the low dose and with poor cycle control.[3] The medication was found to produceestrogenic effects in theendometrium in women due totransformation into estrogenicmetabolites.[4]
A singleintramuscular injection of 50 to 100 mg LPP inoil solution has been found to have aduration of action of 14 to 30 days in terms of clinicalbiological effect in theuterus and onbody temperature in women.[9]
LPP has a longbiological half-life in rats when given as an intramusculardepot injection; its half-life was similar to that ofnandrolone laurate (nandrolone dodecanoate) and was about 2-fold longer than that ofnandrolone decanoate, 10-fold longer than that oflynestrenol andnandrolone phenylpropionate, 50-fold longer than that ofprogesterone, and 430-fold longer than that ofnandrolone.[5][6]
| Compound | Form | Dose for specific uses (mg)[c] | DOA[d] | |||
|---|---|---|---|---|---|---|
| TFD[e] | POICD[f] | CICD[g] | ||||
| Algestone acetophenide | Oil soln. | – | – | 75–150 | 14–32 d | |
| Gestonorone caproate | Oil soln. | 25–50 | – | – | 8–13 d | |
| Hydroxyprogest. acetate[h] | Aq. susp. | 350 | – | – | 9–16 d | |
| Hydroxyprogest. caproate | Oil soln. | 250–500[i] | – | 250–500 | 5–21 d | |
| Medroxyprog. acetate | Aq. susp. | 50–100 | 150 | 25 | 14–50+ d | |
| Megestrol acetate | Aq. susp. | – | – | 25 | >14 d | |
| Norethisterone enanthate | Oil soln. | 100–200 | 200 | 50 | 11–52 d | |
| Progesterone | Oil soln. | 200[i] | – | – | 2–6 d | |
| Aq. soln. | ? | – | – | 1–2 d | ||
| Aq. susp. | 50–200 | – | – | 7–14 d | ||
Notes and sources:
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Studies were made with nandrolone phenpropionate (Durabolin), nandrolone decanoate, and 16α-ethylprogesterone in peanut oil injected into the gastrocnemius muscle of rats. The free steroid was much more rapidly resorbed than the esters, explaining the action-prolonging effects obtained with the latter. Generally, resorption rates correlated well with duration of action. Resorption from the muscle was followed by transport to the receptor site in the body, during which time ester hydrolysis may occur, releasing the free steroid. Resorption and hydrolysis take place independently, since plasma with inactivated enzymes (heated to 55°) eluted the compds. from a filter paper strip as rapidly as did normal plasma.
17α-Hydroxyprogesterone caproate is a depot progestogen which is entirely free of side actions. The dose required to induce secretory changes in primed endometrium is about 250 mg. per menstrual cycle.
The results showed that after injection the concentration of plasma MA increased rapidly. The meantime of peak plasma MA level was 3rd day, there was a linear relationship between log of plasma MA concentration and time (day) after administration in all subjects, elimination phase half-life t1/2β = 14.35 ± 9.1 days.