Do you expand Brew Potion?

[Ahrimon]

There was an option in Tome and Blood that let you brew potions with spells higher than 3rd. You had to have brew potion and craft wonderous item. If you had the two feats you could make potions with higher level spells. I can't recall if there was a limit to the spell level using that combination though.

 

[Quartz]

I was looking at something today and it seems that oils, elixirs, and the like are classed as potions, so that answers the first part of my OP.