The product is called "Gel-Tek Ultra Cure PX". and is made by Aquarium Products. Here's a link:
http://www.aq-products.com/GelTek/ultracurepx.htm
Stumbled across this by accident while I was looking for a different product (anti-parasite medicated food made by Jungle labs). The only place I've found it is at Petland.
I originally went hunting for it when getting ready to purchase my rabbitfish as they supposedly are prone to internal parasites. An article in the 2008 Reefkeeping Annual recommended using praziquantel, flubenol and metronidazole as a multi-pronged approach. Fortunately, this product has all three. Although they advertise that it has fish pheremones to enhance feeding, my fish won't touch it on it's own. I mix it with mysis the night before and then skip my morning feeding. By late afternoon the fish are pretty hungry and gulp down every piece. That way I reduce the risk of harming any inverts with the meds...so far no problems, not sure on how effective though either as none of my fish have had parasites that I could see.