Vaginal rings medroxyprogesterone acetate

As early as 1978, the vaginal administration of steroids for contraceptive purposes was attempted, at that time using vaginal rings containing medroxyprogesterone acetate or... 

Fig. 10 (A) Serum concentrations of medroxyprogesterone acetate after a daily oral administration of a medroxyprogesterone acetate tablet (10 mg) taken by a healthy woman before breakfast for five consecutive days. (B) Daily serum concentrations of medroxyprogesterone acetate in women wearing medicated silicone vaginal rings (2% medroxyprogesterone acetate) for 20 days. (From Ref. l)...

Vermeulen, A. Dhondt, M. Thiery, M. Vandekerckhove, D. Plasma sex steroid and gonadotropin levels in control and silastic vaginal medroxyprogesterone acetate-impregnated ring cycles. Fertil. Steril. 1976, 27, 773-779. 

The use of a silastic vaginal ring impregnated with medroxyprogesterone acetate and inserted on day one of the cycle for 28 days represents yet another variation of the depot concept [167]. LH release and ovulation were inhibited as expected. Removal of the ring was followed by withdrawal bleeding in about 48 hours. In contrast to the depot injection, this technique provides rapid termination of drug action. 

---