EDIT: Came out with PoR 2/21/2006 http://eqplayers.station.sony.com/game_updates.vm?date=2/21/2006
EDIT: All assumes you mean the new potions, made with the new alchemy system and sold premade by vendors. As there were some original (or at least by Kunark era) potions sold by vendors.
EQ Players patch notes appears down atm, so here's a cached version from June 2005:
http://webcache.googleusercontent.com/search?q=cache:upe4A9S0pOgJ:eqplayers.station.sony.com/game_updates.vm%3Fdate%3D6/29/2005+everquest+2006+patch+notes+potion+vendor&cd=1&hl=en&ct=clnk&gl=us&source=www.google.com
Another Alla patch notes from 2006, and was the time I was thinking, but they may have been in earlier, and I just not realized it, as I was out of game almost all of 2005:
https://everquest.allakhazam.com/story.html?story=7087 Alot of the new potions were entered in EQItems in spring (Mar / Apr) of 2006, so probably were introduced in 2005 (DoN or DoDh expansion?).
Edited, Jun 8th 2011 3:39am by Yther Yther Ore.
Edited, Aug 11th 2011 7:56am by Yther