Mechanical testing methods for drug-releasing vaginal rings.

Vaginal rings (VRs) are currently marketed for contraceptive or hormone regulation purposes, and investigationally, have been widely reported for delivery of antiretrovirals to reduce HIV transmission. To date, there is no national or international standard for the mechanical testing and minimum performance characteristics of any VR based products. Here, we describe a series of mechanical tests examining the durometer hardness, static and dynamic compression response, tensile properties and twist resistance of vaginal rings.