Drug Information for Femring (estradiol acetate vaginal ring) (Warner Chilcott (US), LLC): DESCRIPTION

Femring^® (estradiol acetate vaginal ring) is an off-white, soft, flexible ring with a central core containing estradiol acetate.

Femring is made of cured silicone elastomer composed of dimethyl polysiloxane silanol, silica (diatomaceous earth), normal propyl orthosilicate, stannous octoate; barium sulfate and estradiol acetate. The rings have the following dimensions: outer diameter 56 mm, cross-sectional diameter 7.6 mm, core diameter 2 mm.

Femring is available in two strengths: Femring 0.05 mg/day has a central core that contains 12.4 mg of estradiol acetate, which releases at a rate equivalent to 0.05 mg of estradiol per day for 3 months. Femring 0.10 mg/day has a central core that contains 24.8 mg of estradiol acetate, which releases at a rate equivalent to 0.10 mg of estradiol per day for 3 months.

Estradiol acetate is chemically described as estra-1,3,5(10)-triene-3,17ß-diol-3-acetate. The molecular formula of estradiol acetate is C₂₀H₂₆O₃ and the structural formula is:

The molecular weight of estradiol acetate is 314.42.