Progestin production

Follicular Growth and Ovulation, Estrogen and Progestin Production... 

Male and female hormones are produced primarily in the gonads. Androgens are synthesized in the testes in the male. In the female, the ovaries are the principal sites of estrogen and progestin production. As discussed in Chapter 29, small amounts of sex-related hormones are also produced in the adrenal cortex in both sexes, which accounts for the fact that small amounts of hormones of the opposite sex are seen in females and males that is, low testosterone levels are seen in females, and males produce small quantities of estrogen. However, under normal conditions, the amounts of sex-related hormones produced by the adrenal cortex are usually too small to produce significant physiologic effects. 

The seven dmgs and the combination estrogen-progestin product presently approved in the US for delivery by the transdermal route were all well known and available in more conventional dosage forms before their formulation into skin patches . All of these dmgs are extremely potent, none requiring more than about 20 mg per day (and some, much less) for effective therapy. 

The 1950s and 1960s saw the development of orally active progestins based on the synthesis of steroids that lack the C19-angular methyl substituent (19-norsteroids). The commercial production of these compounds for the regulation of menstmal disorders began in 1957, and for oral contraception in 1960. 

Implanted Contraceptives. Controlled release of contraceptive progestins also can be accompHshed by incorporating the dmg into an implantable cylinder or rod. The best known implant is Norplant, developed by the Population Council. Norplant is composed of six matchlike silastic cylinders with the progestogen levonorgestrel (11) incorporated on the inside of each cylinder. After implantation under the skin, the product can provide effective contraception for a period of five years (43,44). Since silastic is not biodegradable, the implant can be removed from a patient at any time. 

Intrauterine devices are medical products that prevent conception when placed in the utems. In spite of their ancient origins, modem intrauterine devices (lUDs) have been widely used only in the last 30 years. The two generic subclasses of lUDs are nonmedicated (inert) devices and medicated lUDs, ie, progestin-releasing and copper lUDs. 

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