There are a few different ways to find inactive ingredients of a medication. My absolute favorite by far only works for pills, but I always check it first. It’s a brand new search engine from the NIH called Pillbox. In fact, it’s so new it’s still in beta stages.
This search engine is intended for identifying “mystery” pills, but I’ve been using it to get a quick list of every manufacturer of a particular drug and the inactive ingredients.
Here’s a brief tour:
Go to http://pillbox.nlm.nih.gov/ and click on Advanced Search (picture on the right).
In “Drug Name,” enter the name of the drug you’re looking for. In this case, I’ve entered cephalexin, the generic name of Keflex. This will give me both the brand-name drug and all generic variants. Click Search.
The search results will give you a listing of all known manufacturers and dosages of the drug, with the inactive ingredients listed right on the page. You can click hide/show next to “Inactive Ingredients” to see the full listing.
If I can’t find what I’m looking for on this search engine, or need more details, my next go-to search engine is NIH’s DailyMed database, which is an archive of package inserts for all kinds of medication and medical supplies.