That is a synthesized compound that replicates necrotic destruction of flesh.

["Synthesized". It's her own venom that she's been milking and tinkering with.]

I'm trying to eliminate the necrotic element in half and strengthen it in the other half, but unfortunately, chemistry is not my area so it's taking me longer than anticipated. It can't be exposed to sunlight in this form, thus the relatively unorthodox method of storage.

If you drink it in it's current state, it'll eat a hole through your stomach.