This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Micro dosing studies done in which phase of clinical trials? 
Select and explain. 
A. 0, B. 1, C. 2, D. 3
A: 0
Answer: A: 0 
Explanation: Ans. is 'a' i.e., 0 Phase 0 - Microdosing strategy in clinical trials Drug development is an activity that is long, complex and expensive. The concept of microdosing involves the use of extremely low, nonpharmacologically active doses of a drug to define the pharmacokinetic profile of the medication in human subjects. Microdosing, thus, appears as a new ble concept in the 'toolbox' of the drug development activity.