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.
Estriol sulfamate
Estriol sulfamate (developmental code name J1034), or estriol 3-"O"-sulfamate, is a synthetic estrogen and estrogen ester which was never marketed. It is the C3 sulfamate ester of estriol. The drug shows substantially improved oral estrogenic potency (vagina, uterus) relative to estriol in rats but without an increase in hepatic estrogenic potency. However, the closely related compound estradiol sulfamate (E2MATE) failed to show estrogenic activity in humans, which is due to the fact that it is additionally a highly potent inhibitor of steroid sulfatase and prevents its own bioactivation into estradiol.