The Effect of Drug Content Reduction on the In Vitro and In Vivo Properties of Levonorgestrel-Releasing Intravaginal Rings.

Intravaginal rings (IVRs) are an option for continuous administration of drugs in women. However, a considerable amount of excess drug often remains in the ring upon removal. The current study focuses on comparing 2 IVRs releasing levonorgestrel (LNG).