Butyronitrile Rubber Stopper for Pharmaceutical Oil Solvent  professional design for the veterinary medicine which contained moreoil solvent, during manufacturing process,most of the factories use halogenate stopper like Halogenated butyl rubber Stopper,and during stability accelerated test for the content of API,we can find the stoper sawllow the content of APIs.But if use Butyronitrile Rubber Stopperhalogenate,we can reduce this swallow.