{"data":{"id":"us/21-cfr-320.35","jurisdiction":"us","citation":"21 CFR 320.35","heading":"Requirements for in vitro testing of each batch.","body":"If a bioequivalence requirement specifies a currently available in vitro test or an in vitro bioequivalence standard comparing the drug product to a reference standard, the manufacturer shall conduct the test on a sample of each batch of the drug product to assure batch-to-batch uniformity.","path":["Title 21—Food and Drugs","CHAPTER I—FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES","SUBCHAPTER D—DRUGS FOR HUMAN USE","PART 320—BIOAVAILABILITY AND BIOEQUIVALENCE REQUIREMENTS","Subpart B—Procedures for Determining the Bioavailability or Bioequivalence of Drug Products"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-21.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:24:47Z","sha256":"88671355628124735f17147b8267384388c521cf34a573fff42db3e6ca491062","source_id":"us-cfr","stale":true,"prev":"us/21-cfr-320.34","next":"us/21-cfr-320.36"},"notice":"GroundRules: Original legal text. Not legal advice."}