**4.2 Comparative bioavailability studies of new drugs (NDA)**

Comparative bioavailability studies for new drug are used to conduct to determine the bioavailability and bioequivalence of the formulation in humans for safety and efficacy. Information about bioavailability of new drug formulation is obtained by comparing the pharmacokinetics parameters of an intravenous and oral administration of new drug formulations having the same dose [26].

## **4.3 Comparative bioavailability of generic drugs (ANDA)**

When a manufacturer wishes to gain therapeutic equivalence for introducing a competitive generic product into the market place, it is not necessary to conduct the full batch of clinical trials needed for the first product. If therapeutic equivalence has been determined, study has to be carried out according to prescribed study requirements, and it should be similar or equivalent to the previous or innovator product. This is regarded as therapeutically equivalent to the innovative drug product [27].
