In recent years, the costs for drug research and development (R&D) have escalated despite the fact that new technology is evolving and has greatly accelerated the R&D process for new drugs. To aid in the drug R&D
process, FDA, as part of their critical path initiative, released a guidance for Exploratory IND studies (or Phase 0 clinical trials) which are intended to provide clinical information for a new drug candidate at a much earlier phase of drug R&D process. Microdose is a primary tool in exploratory IND to allow the collection of human pharmacokinetic and pharmacodynamic data earlier in the drug R&D process. Since microdosing
approach is designed not to induce any pharmacological effects, these studies are safe to the participating human subjects. Microdosing studies also can be initiated with fewer preclinical safety studies, as well as
require lesser resources and time for selecting promising drug candidates for further evaluation.