In vitro and in vivo permeation studies during the development of a novel transdermal gel containing an estrogen and a progestagen (CombiGelcircle R)

摘要

The goals of estrogen replacement therapy are to treat symptoms of menopause and to reduce the risks of osteoporosis and artherosclerotic heart disease. To accomplish these purposes, the different transdermal formulations of 17-#beta#-estradiol (E_2) to raise plasma levels between the range of 40-60 pg/ml. That is the plasma level found during the early follicular phase of perimenopausal women. However, unopposed estrogen therapy may induce endometrial hyperplasia. Thus, the administration of progrestagen together with estrogen is highly recommended in nonhysterectomized women, in order to protect the endometrium.