One in 5,000 compounds that enter the preclinical testing make it to human testing, and only 1 in 5 is approved for sale. The pharmaceutical company conducts laboratory and animal studies on the drug. They also determine how a drug is absorbed, distributed, metabolized and excreted, as well as the duration of its action.
Physicians monitor patients closely to confirm efficacy and identify adverse events.
Following the completion of all three phases of clinical trials, a company analyzes all of the data and files and new drug application with the FDA if it passes muster. The NDA contains all the scientific information that the company has gathered, and typically runs 100,000 pages or more. Once the FDA approves a new drug application, the new medicine becomes available for physicians to prescribe. This information is not intended to be a substitute for professional medical advice. You should not use this information to diagnose or treat a health problem or disease without consulting with a qualified healthcare provider.