Shawn F. Carnes from Artifact Entertainment wrote an interesting developer diary about Alchemy at Horizons Warcry. Altough you should skip the snippet below and just go read the article right away, here's one anyway:

The first step in bringing Alchemy to Horizons was to design the concepts behind what function it would serve within the game. A lot of fantasy games use Alchemy in different ways, both broad and narrow in scope. For Horizons, Alchemy will be relatively broad in scope, meaning that there will be a variety of uses potions will have in the game world. Alchemy will mirror some spell effects, though the potions in general shouldn’t be completely equitable to what someone can do with a spell. There will be some things, however, that potions will do that spells necessarily won’t. This doesn’t mean, however, that they can’t do those things. With the way we have our systems set up, the predominant differences between spells, special abilities, potions, and even food, are all based on content choices. All the information is related in our database, and it is up to us as designers to create a niche for each part so that it might stand on its own. For Alchemy, you’ll see potions do that with lesser versions of spell effects, as well as bending game constraints we place on the system.