Review of Pre-Clinical Trial results. Determination of safety to use on humans. Authorization to ship across state lines.
Investigational New Drug Review
Involves a small number of healthy volunteers (25-100). Safely tolerated dosages determined. Identification of major side-effects. Emphasis on safety and maximum tolerated dosages.
Involves many more volunteers (100-300). Emphasis on the drugs effect against what it's designed to treat. Effects compared with similiar patients receiving different treatments.
Involves a few more volunteers (300-3000). Emphasis on the drugs overall effect. Effects compared with patients unknowingly taking placebos. Study of different populations and different dosages. Testing the drug in combination with other drugs. Final Phase before presenting to FDA for approval.
Ongoing/Post approval trials. Health care professionals to report any adverse findings. this phase lasts eternally as long as the drug is on the market.