Absorption of Estrogens from Vaginal Creams

The substantial intestinal conversion of estradiol to estrone, observed after oral administration of est radiol,3 is circumvented by intravaginal application, and this findings prompted us to investigate the potential for absorption of estrogenic substances contained in vaginal cream.

Abstract

INTRAVAGINAL application of estrogen-containing creams has been widely used in the treatment of vaginal atrophy and related conditions due to estrogen deficiency. Although its efficacy is well recognized,1 , 2 the assumed "topical" effect and the potential for absorption of estrogenic substances contained in the vaginal cream are virtually unexplored.Recent observations indicate that the efficacy of absorption of micronized 17β-estradiol yields blood estradiol levels 100 times higher when administered intravaginally in salines than when given by mouth.3 , 4 Moreover, the substantial intestinal conversion of estradiol to estrone, observed after oral administration of estradiol,3 is circumvented by intravaginal application. These findings prompted us . . .