Effects of vaginally administered high estradiol doses on hormonal pharmacokinetics and hemostasis in postmenopausal women

Effects of non-oral postmenopausal hormone therapy on markers of cardiovascular risk: a systematic review

“…One study had an untreated control group (96), the other studies all had an oral comparison group. No randomized trials on the effects of other non-oral administration routes were found; only one uncontrolled study reported on the effects of vaginally administered E 2 on cardiovascular risk markers (107).…”

Drug delivery systems for oestrogenic hormones and antagonists: the need for selective targeting in estradiol-dependent cancers

“…On the other hand, administration by vaginal ring was similar in terms of drug delivery to the estradiol-releasing transdermal patch, and vaginal delivery has been effective in preventing climacteric symptoms in post-menopausal women [103,104]. In the light of the large variability of serum estradiol profiles within and between all the subjects [105,106], widely varying results render it difficult to compare the various treatment alternatives and the doses needed.…”

Permeability of tritiated water through human cervical and vaginal tissue

“…Drug absorption through vaginal mucosa has been identified as an alternative route of administration for medicines in order to eliminate first pass metabolism. Several investigators have showed bioavailability of drugs delivered at the vaginal mucosa site 25–28. Corbo et al25 demonstrated that vaginal administration of progesterone in rabbits significantly improved systemic bioavailability over that obtained by oral administration.…”

“…Currently, hormone replacement and contraceptive products administered vaginally are available in the market. It has been shown that systemic effects are observed with these products when administered intravaginally 7–29. Given this information combined with the data presented, the importance of studying the potential for systemic uptake of drugs by these mucosa must be evaluated for development of safe and effective vaginal drug delivery systems.…”