This is created from gathering emerald dragon poison. Each vial collected from the dragon creates 5 poison vials to apply to your weapon. You can use the magic poison in this vial to coat one slashing or piercing weapon or up to a quiver full of ammunition. Applying the magic poison takes an action. A creature hit by the magically poisoned weapon or ammunition must make a DC 12 Constitution saving throw or take 2d4 poison damage, half damage on a successful save. Once applied, the magic poison retains potency for 24 hours before the magic dissipates.

To create a vial with 5 charges you need the following items and crafting requirements.

Items: Poison gland from a young dragon (creates 5 vials), scavenge poison from breath attack (up to 2 vials) or scavenge from punctured gland if you fail to successfully retrieve gland (up to 2 vials). Clear glass vials.

Creation: Alchemical supplies. Alchemy table. A full work week of brewing (8 hours each day for 5 days)