Ways to increase formula DCs for an alchemist/investigator?

[Ellrin]

I can't think of any ways to increase formula DCs short of increasing Intelligence. I mean, sure, there aren't that many formulae that would provoke saves under normal circumstances, but you do have things like polymorph form abilities, touch injection, and full pouch that would all benefit from higher DCs. Spellcasters have feats like Spell Focus and Heighten Spell, at the very least, as well as a few other DC-boosting options; but I can't think of anything like that explicitly worded to work with extracts.

So what options exist to boost an extract's DC? I'll even look at third-party material, though first-party would be preferable.

[Grod_The_Giant]

Ability Focus?

[Ellrin]

Does the ability to create extracts count as a special attack? If so, I guess a single feat that simulates Spell Focus AND Greater Spell Focus for every school isn't too bad.

[Grod_The_Giant]

Does the ability to create extracts count as a special attack? If so, I guess a single feat that simulates Spell Focus AND Greater Spell Focus for every school isn't too bad.
I've heard it argued, but I've never bought it. I was suggesting that if individual extracts don't count as spells, they ought to count as SOMETHING Ability Focus works with.

[Florian]

So far, there´s is no way to boost the DC of extracts. And no, Ability Focus doesn´t work.