**1.2 When no need of bioequivalence studies**

In some formulations, bioequivalence studies are not required if bioequivalence between a test drug and a reference drug may be considered self-evident with no further requirement for documentation such as when a gas is in the form of test drug, when test drugs are to be administered parenterally such as subcutaneous, intramuscular, intravenous, etc. as aqueous solution and contain the same drug in the same concentration and the same excipients in comparable concentrations. Bioequivalence studies are not required for when the test drug is in the form of solution for oral use and contains the drug in the same dose and does not contain an excipient that is known to affect gastro-intestinal absorption of the drug; when the test drug is in the form of an ophthalmic or topical product prepared as aqueous solution and contains the same active ingredients in the same concentrations and essentially the same excipients in comparable concentrations when the test drug is in the form of powder for reconstitution as a solution and the solution meets either above second and third points, when a test drug is in the form of an inhalation or a nasal spray tested by administered with or without the same device used for reference drug.
