What’s the problem with generic antiepileptic drugs?

Abstract

The FDA designates a generic drug as therapeutically equivalent to the reference compound (usually the brand-name drug) if it contains the same amount of active ingredient in the same dosage form and meets the same standards for strength, quality, purity, and identity.¹ Two pharmacokinetic measures, the area under the drug concentration-time curve (AUC) and maximum concentration (C_max), are used to determine bioequivalence (and by extension from these surrogate measures, therapeutic equivalence). Equivalence is established when the 90% CI of the ratio of the generic to reference compound for the AUC and C_max fall within an 80% to 125% range. The in vivo bioequivalence testing is typically done in 24 to 36 healthy adults.