What is an acceptable criterion for determining that a study of an approved drug does not require an Investigational New Drug (IND) application?

When determining whether a study of an approved drug requires an Investigational New Drug (IND) application, one of the critical considerations is whether the study is being conducted for a new indication. An IND application is necessary if the study involves a new use or a different population than what the drug was initially approved for.

In this context, if the study is not reported to the FDA for new indications, it implies that the investigation is focused on the existing indications for which the drug has already received approval. This means the study does not pursue new therapeutic avenues, thus potentially exempting it from the IND requirements.

The other options present scenarios that do not inherently justify the exclusion from the IND application requirement. Conducting a study for internal use, outside the U.S., or involving only healthy volunteers does not alone align with the criteria under which an IND is required or not. The primary concern is whether the clinical investigation seeks to explore new clinical use, dosage, or patient population beyond the originally approved labeling. Thus, the correct answer reflects the understanding of regulatory criteria concerning IND applications.