Vaginal ring delivery of hormone replacement therapy--a review

Vaginal ring delivery systems are a highly promising approach to hormone replacement therapy (HRT). The vagina is an excellent route for steroid absorption. Menopausal vaginal rings can be designed to allow very low dose local delivery of oestrogen to the vagina for the large percentage of postmenopausal women experiencing urogenital atrophy, or can be modified to deliver much higher doses sufficient for systemic oestrogen replacement therapy, with or without simultaneous progestogen release. Clinical studies of ultra-low dose rings have shown them to be as efficacious as established treatments of urogenital atrophy (creams, pessaries) and to be preferred by most users. Pharmacokinetic and limited clinical studies of vaginal rings designed to deliver systemic doses of HRT (oestrogen alone or combined) have also been highly promising. Vaginal ring delivery of HRT offers women convenient, long-acting therapy (>/= 3 months) that is under their own personal control.