Estradiol (medication)
Estradiol is available in a variety of different formulations, including oral, intranasal, transdermal/topical, vaginal, injectable, and implantable preparations. An ester may be attached to one or both of the hydroxyl groups of estradiol to improve its oral bioavailability and/or duration of action with injection. Such modifications give rise to forms such as estradiol acetate (oral and vaginal), estradiol valerate (oral and injectable), estradiol cypionate (injectable), estradiol benzoate (injectable), estradiol undecylate (injectable), and polyestradiol phosphate (injectable; a polymerized ester of estradiol), which are all prodrugs of estradiol.
Estradiol enantate/algestone acetophenide
Estradiol enantate/algestone acetophenide, also known as estradiol enantate/dihydroxyprogesterone acetophenide (E2-EN/DHPA) and sold under the brand names Perlutal and Topasel among others, is a form of combined injectable birth control which is used to prevent pregnancy. It contains estradiol enantate (E2-EN), an estrogen, and algestone acetophenide (dihydroxyprogesterone acetophenide; DHPA), a progestin. The medication is given once a month by injection into muscle.
E2-EN/DHPA is used widely throughout Latin America, is also marketed in Hong Kong, and was previously available in Portugal and Spain as well but was discontinued in these countries.