For prescription meds I often can get physician samples in blister packs. I can cut down the excess material. Seems to work o.k.

For medications I pack myself, I have used my foodsaver vacuum packer. Works fine, and you can trim away excess plastic. Problem is what to do with remaining meds. once opened. Rolling the bag up isn't a very secure option.

Now I most often use some small centrifuge vials I got at a lab supply company. They're polycarbonate, with a screw top, and look like tiny test tubes. I put a piece of clear tape on the vial and label with a waterproof marker.