Selection and extraction
We selected ‘scientific guidelines’ and ‘related documents’ (defined as: reflection papers, public statements and questions and answers documents) via the EMA scientific guideline search functionality [3], which were adopted and published in the period 2013-2017. Excluded from the extraction were product specific bioequivalence guidance, International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) guidance and concept papers (as for the latter comments are not published).