Generic drug approval hinges on demonstrating bioequivalence to the brand-name drug. This means the generic drug must have the same active ingredient, dosage form, strength, route of administration, and quality as the original. To prove this, rigorous clinical trials are conducted.
These trials typically involve comparing the generic drug’s pharmacokinetic (how the body processes the drug) and pharmacodynamic (how the drug affects the body) properties to those of the brand-name drug in a controlled study. Researchers measure parameters like the rate and extent of absorption, peak concentration, and time to peak concentration in blood samples.
The number of participants needed varies depending on the drug and its characteristics, but usually ranges from dozens to hundreds. Stringent statistical analysis confirms whether the generic drug meets the pre-defined bioequivalence criteria, usually expressed as a predetermined range of acceptable ratios between the generic and brand-name drug’s measurements. If the data show bioequivalence, regulatory agencies, like the FDA in the United States, then approve the generic drug for marketing.
Data integrity and rigorous study design are paramount for approval. Agencies scrutinize every aspect of the trial, including participant selection, methodology, data collection, and analysis. Any deviation from accepted standards results in rejection or requests for additional studies. Therefore, successful generic drug approval requires meticulous planning and execution of clinical trials.
