well...lets see...how would you get it out? the only way i would think is with a really low gauge pin and trying to suck it out. otherwise you take the chance of contaminating the sterile environment (that is if you take the rubber stopper off, though you can alsways resterilize the gear if needed). i would just continue with it in the vial. as long as you still see it everytime after you load the syringe...that means you are not injecting it in yourself.
i agree with X filter it into another bottle cuz if you happen to inject even a tiny bit of that rubber just imagine the possible infection you could develop, for the miniscule cost of a filter its worth it for my peace of mind....at least i would think......
This is why i use 25g pins. A 25g pin is a filter of itself. Everyone who has done this for a while has regularly had rubber in their bottles. Just suck it out with 18g and shoot with 25g. If your still woried do waht MR.X says and you will be fulproof..