The structurally related estrogens, estrone (E1), estriol (E3), and estetrol (E4) have one, three, and four hydroxyl groups, respectively. Hemihydrate
A hemihydrate form of estradiol, estradiol hemihydrate, is widely used medically under a large number of brand names similarly to estradiol. In terms of activity and bioequivalence, estradiol and its hemihydrate are identical, with the only disparities being an approximate 3% difference in potency by weight (due to the presence of water molecules in the hemihydrate form of the substance) and a slower rate of release with certain formulations of the hemihydrate. This is because estradiol hemihydrate is more hydrated than anhydrous estradiol, and for this reason, is more insoluble in water in comparison, which results in slower absorption rates with specific formulations of the drug such as vaginal tablets. Estradiol hemihydrate has also been shown to result in less systemic absorption as a vaginal tablet formulation relative to other topical estradiol formulations such as vaginal creams. Estradiol hemihydrate is used in place of estradiol in some estradiol products. Derivatives
A variety of C17β and/or C3 ester prodrugs of estradiol, such as estradiol acetate, estradiol benzoate, estradiol cypionate, estradiol dipropionate, estradiol enantate, estradiol undecylate, estradiol valerate, and polyestradiol phosphate (an estradiol ester in polymeric form), among many others, have been developed and introduced for medical use as estrogens. Estramustine phosphate is also an estradiol ester, but with a nitrogen mustard moiety attached, and is used as a cytostatic antineoplastic agent in the treatment of prostate cancer.
Vestibular papillomatosis (VP) are normal small bumps in the genital area of females. They appear in multiple numbers, are rounded and are not painful, itchy or uncomfortable. They are analogous to pearly penile papules, which occur in males.They are not infectious and are not due to HPV. Diagnosis is by visualization. The bumps are less yellow and more pinkish when compared to Fordyce spots. They should not be mistaken for genital warts. No treatment is required.They are common in pregnancy. Historically they were sometimes incorrectly called "microwarts". == References ==