21 CFR 320 (Title 21 Code of Federal Regulations Part 320)

21 CFR 320 outlines the regulations for "Bioavailability and Bioequivalence Studies" of drugs. It sets standards for how pharmaceutical companies must demonstrate that their medicines are absorbed, distributed, metabolized, and excreted in the body similarly to existing, approved drugs. These studies ensure that generic drugs work as effectively and safely as their brand-name counterparts. The regulation defines the methods, conditions, and documentation necessary for these studies, ensuring consistent, reliable data that supports the approval and use of interchangeable medications.