A testing drug is classified as bioequivalent to the reference drug if which of the following conditions is met?

For a testing drug to be classified as bioequivalent to a reference drug, it is essential that all relevant pharmacokinetic parameters are closely matched. Bioequivalence means that the rate and extent of absorption of the test drug are not significantly different from that of the reference drug when administered at the same molar dose under similar conditions.

The time to reach peak plasma concentration is one important parameter. If this time is similar between the two formulations, it indicates that the drugs are delivering their active ingredients to the bloodstream at comparable rates.

Additionally, the peak plasma concentration is significant because it reflects the maximum concentration of the drug in the blood, which can correlate with the drug's efficacy and safety profile. Similar peak concentrations suggest that both drugs are likely to exert similar therapeutic effects.

The area under the curve (AUC), which represents the total exposure of the body to the drug over time, is another critical factor. AUC similarity indicates that the overall amount of the drug absorbed into the systemic circulation is comparable, which is vital for ensuring that therapeutic effects are maintained.

Thus, to establish bioequivalence, all these parameters—time to peak concentration, peak plasma concentration, and AUC—must be considered collectively. This comprehensive approach ensures that the testing drug