You can check for types of medications WITHOUT certain ingredients.
Daily Meds- site is located here. It is another site for checking medications.
This is what I was told about calling manufacturers for information on ingredients: "You will likely get better info on the government sites than calling the company.
Manufacturers have to file accurate ingredient lists with the government, but can put vague ingredients on the packaging like modified food starch.
Type in the words "professional information on" or "prescribing information" and the name of the drug to see the information that your doctors see- the most complete information without writing the company. (Thanks to Lymetoo for this helpful information above.)