Purpose-made containers really would make a lot of sense, regardless of whether potions were very rare and valuable, and thus warranting of custom containers, or very common, and therefore being commodities easily identified and organized.
All tagged potion
Oddities for an Alchemist's Laboratory
An alchemist's workshops is a wonderland where miraculous cures and pseudoscientific abominations are spawned from the minds of geniuses in varying degrees of madness and torture.
Craft Alchemical Grenade (OGL Item Creation Feat)
You're not really an alchemist unless you've survived a few laboratory explosions. But suppose you want to cause an explosion on purpose?
Eagle Medicine, A 5e Potion
Floating within this thick red syrup is a single pin feather from an eagle. When consumed, this potion transforms you into an eagle!
Spore Body Elixir, a Potion for 5e
Suspended in this thick, chalky potion is a living puffball mushroom. When you drink this potion your body transforms into a cloud of fungal spores.
Ironbone Medicine: A Potion for 5e
This potion imparts proof against bludgeoning damage.
