Bioequivalence
A regulatory standard proving that a generic drug delivers the same amount of active ingredient to the bloodstream at the same rate as the brand-name drug.
How It Works
Bioequivalence (BE) is the foundation of generic drug approval. The FDA defines two products as bioequivalent if their rate and extent of absorption do not differ significantly. This is typically measured in pharmacokinetic studies: healthy volunteers take the generic and brand-name drug in a crossover design, and blood levels are compared. The FDA requires that the generic's key pharmacokinetic parameters (Cmax and AUC) fall within 80-125% of the brand-name drug's values. In practice, the average difference between generics and brand-name drugs is only 3-4%. Bioequivalence allows generics to skip the full clinical trial process, dramatically reducing development costs.
Related Terms
- Generic Drug — A medication that contains the same active ingredient, dosage, and form as a brand-name drug, approved after the original's patent expires — typically costing 80-95% less.
- Abbreviated New Drug Application (ANDA) — The FDA application pathway for generic drugs, which requires proving bioequivalence to the brand-name drug rather than repeating full clinical trials.
- FDA Approval — The process by which the U.S. Food and Drug Administration evaluates a drug's safety and efficacy through clinical trial data before allowing it to be marketed.
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About This Definition
This definition is part of the DrugPrice Drug Pricing Glossary — 34 terms explaining how prescription drug pricing works in the United States. All definitions are written in plain language for patients, caregivers, journalists, and healthcare professionals.