I made this small container for three 0.5ml eyedrop ampoules to keep them upright and protect them from dust. It fits both closed and opened ampoules.

caveat: if you want to carry opened ampoules, you obviously need to keep them upright to prevent spillage, or seal them with a stopper. Opened ampoules are usually fine to use for up to 24h if you keep the opening clean (i.e. don't touch it).

Print both parts with the bores facing up. No support needed.

I'm including the F360 file for easy remixing.