Development of an injection molded ethylene-vinyl acetate copolymer (EVA) intravaginal insert for the delivery of progesterone to cattle.

The purpose of this study was to develop a new injection-molded intravaginal insert manufactured from ethylene-vinyl acetate containing progesterone for a 7-day insertion period in cattle. The manufacturing process resulted in a reduction in the residual drug compared to the silicone insert available while still maintaining biological performance.