So, when is the Save DC for an extract set; when it is used, or when it is made?
To illustrate, say we have Allie, an alchemist capable of creating three second level extracts. Allie prepares one as Fox's Cunning, then drinks it and prepares the other two as, say, Fire Sneeze. Normally, Allie's INT is 18, but with Fox's Cunning it's 22. Is the DC for the Fire Sneeze extract (used, say, two hours later) 16 or 18?