Towards understanding interchangeability of generic drugs

Registered generic drugs are considered interchangeable with brand-name drugs. However, concerns still exist in practice. In this dissertation, the role of individual-subject variation in the drug absorption and the effect of post-marketing drug quality changes were studied for generic and the brand-name drug interchangeability. Generic-generic drug interchangeability was studied in a clinical trial and inter-study comparisons. In conclusion, interchanges of generic to the brand-name drugs or generic to other generic drugs can be applied in clinical practice without clinical consequences. Current regulation for registration of a generic drug in Europe is reasonably strict to ensure the bioequivalence of the generic drug with the brand-name drug.