I don't ever start new topics but I've been thinking about this for quite a while and nobody else has bought it up, so here goes.
Eugene was shown making the pills for Negan's wives, but he didn't hand them over so I think it's safe to assume he still has them. It is my guess that he has hidden them in the teddy bear/doll he stole and has taken to carrying around with him.
What does he plan to do with them? Slipping them to Negan himself would be doomed to fail and could land him in very hot water. Is he going to use them on the other Saviors if the chance comes up? Carrying them around with him is a huge risk, particularly because the wives know he has them and could easily rat him out if they find themselves in trouble for any reason.
I think the pills will come back into the story at some stage so it's probably worth discussing. Feel free to share your thoughts