If you're asking about the tablet ingredients, go to the Watson Labs website (below) and at the bottom of the page is a link for brand and generic products which have ingredient lists.

http://www.watsonpharm.com/new/product_data.asp?page_type=HTML

If you're asking about apap not potentiating hydro, I don't know of a good link, I've just read about this in various places, including DB. In order for anything to really potentiate an opiate drug, it has to be something that actually has a method of action that would somehow alter the way the drug is absorbed or metabolized. Some examples of this are proglumide, which does this by inhibiting an enzyme that contributes to tolerance (or something like that, I'm trying to remember what I read), or stomach acid blockers/reducers like tagamet -- I think they work by limiting the amount of opiate destroyed in the stomach, and increasing absorption. I'm not sure about this so please don't quote me on it, but I think that when you take hydrocodone bitartrate, it is converted to a hydrochloride salt by HCL in the stomach; tagamet prevents this from happening, so a different form of hydrocodone is actually being absorbed when you take an acid blocker, one that hasn't been chemically converted. There is no mechanism by which tylenol has any effect on the absorption or metabolism of opiates. The real reason they put apap into scheduled medications is to reduce the potential for abuse, it's written right into the lawbooks that way. Here's my favorite quote on this subject, from Dr. Harris, who writes on sci.net:

"... the FDA uses APAP for narcotics (including barbiturates) in much the same way methanol is used for ethanol. To wit: as a toxic "denaturation" agent to make sure you don't, or can't, take too much before your liver rots or your kidneys quit. The APAP therefore makes the difference between a lot of schedule II and III drugs. FDA's reasoning is that these drugs *can't* be greatly abused for very long, or the user will be dead or disabled, which is a perfectly fine outcome in the war on drugs (see "war on people").

Now, if you accused the FDA of this deliberate policity, it would deny it. Since of course there are an awful lot of former Darvon abusers on chronic renal dialysis. But that's the way it is.

Steve Harris, M.D."

I think his point at the end about Darvon is that the FDA would claim that since there are many Darvon abusers on dialysis, then how can you accuse us of intentionally poisoning people with apap, since it is Darvocet that has the apap in it. Or something like that. This is just a pet peeve of mine, I didn't mean to go on about it, especially in a pill ID thread.