An overview of regulations for bioequivalence assessment of locally acting orally inhaled drug products for the United States, Europe, Canada, and India

Bioequivalence is established by comparing the bioequivalence study results of generic drugs with the reference listed drug. Several global regulatory agencies have published the guidance for locally acting orally inhaled drug products (OIDPs) for bioequivalence approaches.The prime intent of the present article is to compare the regulatory guidance for bioequivalence assessment of locally acting OIDPs published by global regulatory authorities. Regulatory recommendations on bioequivalence were based on assessment for different parameters such as inhaler device, formulation, reference product selection, in-vitro, and in-vivo studies. The United States Food and Drug Administration and Health Canada suggest an aggregated weight of evidence approach and the European Medicines Agency promotes a stepwise approach, whereas though the Indian authorities have not published guidance specifically on OIDPs but provided guidelines for bioavailability and bioequivalence studies.For OIDPs, currently, there is no universally adopted methodology, and regulatory guidance has not been globally harmonized. By understanding and comparing bioequivalence recommendations for different regions, we can create more sensitive, and economic evaluation methods for OIDPs. This could open more alternatives of safe, effective generic OIDPs to the public.