Menstrual cups have become increasingly popular in recent years for their environmental benefits, cost-effectiveness, and user comfort. Most menstrual cups are made using silicone, taking advantage of its flexible and leak-proof material properties. However, there has been limited research on the hydrolytic degradation of silicone biomaterials, particularly in the acidic vaginal environment, raising potential safety concerns. The objective of this research project is to study the hydrolytic degradation of silicone under acidic conditions to better understand the safety profile of biomedical devices like menstrual cups. Our initial study tested 40 silicone samples over a 29-day period at 37 °C and 67 °C in a 1 M hydrochloric acid (HCl) solution. Results of this accelerated study indicated a maximum mass loss of 11.4 %. Future studies will be performed using a vaginal fluid simulant (VFS) primarily composed of a lactic acid buffer system to assess physiologically relevant degradation behavior and to characterize potentially toxic degradation products. Ultimately, this research aims to develop a standardized workflow for studying the degradation of polymeric biomaterials in a VFS that could also be applied to other biomedical devices such as intravaginal ring (IVR) drug delivery systems.
