Healthy Human volunteers pa of which clinical trial phase?

Ans. is 'a' i.e., I CLINICAL TRAILS Before a new drug comes to the market, it is extensively tested in animals and invitro studies for safety and efficacy. It the drug is found to be promising in these studies, an application called IND (Investigational New Drug) is filed with United States food and drug administration (FDA), which is main regulatory authority. If the permission is granted, then drug is tested in humans. This testing is called clinical trial. These are divided into four phases.