Progestogens

Steroids - Drugs Acting on Endocrine System

PROGESTOGENS

The natural progestational hormone or progestogen is progesterone, which is secreted mainly by the corpus luteum in the second part of the menstrual cycle. Small amounts are also secreted by the testis in the male and the adrenal cortex in both sexes, and large amounts are secreted by the placenta.

Classification

Progestogens could be broadly classified into two major classes:

1. Progesterone derivatives

2. 19-Nor testosterone derivatives

i. Progesterone (Alza)

Synthesis

Method-I From: Diosgenin

Method-II From: Ergosterol

Properties: It exists as white crystalline powder, insoluble in water and in alcohol.

Dose: The dose for uterine bleeding is 5–10 mg injected per day up to 5–10 days. For habitual abortion, the dosage is 5–20 mg twice or thrice a week by IM injection.

ii. Hydroxyprogesterone caproate

Synthesis

Properties and uses: It exists as white crystalline powder, insoluble in water, it is more potent than progesterone, and has longer duration with short onset of action.

iii. Norethindrone (Norethiesterone, Micronor)

Synthesis

Properties and uses: It exists as white crystalline powder, insoluble in water. It is an important oral contraceptive and has the ability to postpone menstruation and prevent ovulation by suppressing pituitary gonadotropin. It is used in combination with mestranol and ethinestradiol.

Assay: Dissolve the sample in tetrahydrofuran, add silver nitrate, and titrate the solution with 0.1 N NaOH. Determine the end point potentiometrically.

Dose: The oral dose for contraception is 2.5–10 mg daily for 21 days.

iv. Norgestrel (Ovrette, Ovval)

Synthesis

Properties and uses: It exists as white crystalline powder, insoluble in water, slightly soluble in alcohol. Used as an oral contraceptive.

Dose: The oral dose as a single agent is 75 μg per day.