There are two that I know of that eat through plastic. Chlormethiazole, and paraldehyde, both sedative-hypnotic/anticonvulsants. Not sure if paraldehyde is still used, but its fucking awful stuff. Melts plastic, it STINKS, and it carries an awful hangover, as it is simply the trimer of acetaldehyde, the alcohol metabolite responsible for causing hangovers and other negative symptoms upon heavy EtOH consumption. (trivia-the tetramer, metaldehyde, is the most common compound used in slug pellets)
Chlormethiazole is the one I take. I've had inexperienced or unknowing pharmacy techs dispense it in plastic bottles before, I did warn them, but no...they refused to give me a glass bottle every script on cost grounds.
I've had to smash bottles open with a hammer before, after the tops got welded to the bottle itself.
I take it for my myoclonus, and to prevent any further seizures from happening, works great. Funny smell to it though, kinda like sulfurous, gone off cider, with hints of diethyl ether/THF, metal, and mint.
I just took a couple to help me sleep tonight, although I have had a few beers. One strictly speaking, isn't meant to drink on it, theres a specific interaction involving decreased clearance, certainly of the EtOH, but quite possibly both. Used for detoxing alkies because of that, but I know my tolerance for alcohol whilst on the stuff. Makes a few drinks hit like a truck full of bricks and last for a lot longer than usual.
After leaving two of the capsules on my computer keyboard for a while once, I now have two matching rice-grain shaped depressed imprints burnt into the top, between the F7 and F8 keys.