Drug regulations and terminology may be confusing (perhaps discouraging) to academic and practicing physicians interested in investigating drugs in clinical studies. The obligations of investigators vary with the administrative category in which the drug studies fall; this is a summary of the administrative categories of drugs and of the obligations of investigators studying drugs from these categories.
Brown GW. Ground Rules for Physicians Who Evaluate Drugs. JAMA. 1968;203(10):857-859. doi:10.1001/jama.1968.03140100039008