Anuradha V. Gore

Comment on "Quality by design approach for understanding the critical quality attributes of cyclosporine ophthalmic emulsion".

■ INTRODUCTION In the publication titled “Quality by Design Approach for Understanding the Critical Quality Attributes of Cyclosporine Ophthalmic Emulsion the authors presented results from their evaluation of whether in vitro (laboratory) analyses can potentially detect effects of varied manufacturing processes on certain physicochemical properties (proposed Critical Quality Attributes (CQAs)) of cyclosporine (CsA) microemulsions. While these results may be relevant to the development of tools for monitoring aspects of product similarity for quality control purposes, there are several critical shortcomings in the analysis that preclude or limit conclusions that the authors present. Most significantly, those shortcomings foreclose any assumption that bioequivalence of cyclosporine ophthalmic microemulsion products is actually associated with, or can be assessed based solely on, the in vitro metrics that the authors identify.