As an action, you can create a vial of foul-tasting, milky tonic. A creature can drink the contents as an action to have advantage on saving throws against being poisoned, and resistance to poison damage for the duration.
If it is poisoned, one poison is neutralized. If more than one poison afflicts the creature, one poison is neutralized at random.
Immunity. You can expend 2 additional catalysts so the creature is immune to the poisoned condition and poison damage.