This document has been prepared by the Working Group on BE (WG/BE) of the Pan American Network on Drug Regulatory Harmonization (PANDRH) with the objectives of contributing to Drug Regulatory Authorities (DRAs) of the Region of the Americas and recommending harmonized criteria concerning the equivalence of drugs. The document consists of two parts:

• The first part refers to scientific criteria for implementing therapeutic equivalence. In developing this part of the document, the WG/BE analyzed in detail the WHO document "Multisource (Generic) Pharmaceutical Products: Guidelines on Registration Requirements to Establish Interchangeability," prepared by the WHO Expert Committee for Pharmaceutical Preparations. The WG/BE decided unanimously to endorse the document and to promote its implementation in the Americas. This document recommends that the 192 WHO Member States tend to the demonstration of therapeutic equivalence and declaration of interchangeability of all multisource products. Also, basic criteria should be established for performing in vivo and in vitro studies to ensure the interchangeability of multisource products without compromising the safety, quality, and efficacy of the pharmaceutical products. The WG/BE also endorsed the criteria of the Biopharmaceutical Classification System (BCS) for waivers of in vivo studies.
• The second part of the document refers to the strategic framework for the implementation of studies of drug equivalence. This part describes the reality of the Region of the Americas, serving the special features of Latin America and considering that most of the multisource products (products of different origin and/or manufacturers) marketed in the region were approved in accordance with the drug registration requirements of each country at the time of their registration. The gradual implementation of equivalence demonstration requirements (BE) through in vivo studies based on the health risk of the products is recommended, and this document describes the methodology, which complements the biowaivers outlined in the BCS of the WHO guidelines. Furthermore, cases are presented for which there are no valid or unified products of reference. Finally, a flow chart is presented that integrates the requirements of meeting good manufacturing practices (GMP), the validity and reliability of the products of reference, and the concept of gradualism in prioritization according to health risk and biowaivers.