If, for example, the drug is to be administered for 10 days, the researcher will give one, three, and five times the standard dose for 20 days. The tests mentioned here are just guidelines, and testing can vary depending on what the initial studies show. If they know a drug is toxic at two times the recommended dose, then the other doses aren't done. If the drug is an injectable, for instance, the FDA wants to know that the product will not contain bacteria or other contaminates. And it could take years or decades to get approval.
Some new products come on the market and are the only one available of that type for a time.
This licensure helps the manufacturer recoup his expenses of bringing that drug to market. To Product Tom Kennedy, DVM, of Bayer products, discussed his company's testing process. He said testing is done on a wide variety of breeds and ages, as the effect of a product can vary even within breeds. It's not good for the horse, the owner, or us. Developing a new drug begins by finding a novel compound and determining the utility of it.