Expression of concern: “PEGylated aceclofenac solid lipid microparticles homolipid-based solidified reverse micellar solutions for drug delivery” [Heliyon 8 (2022) e09247]

A post-publication investigation conducted by Elsevier's Research Integrity & Publishing Ethics team on behalf of the journal could not confirm whether or not ethical approval was given for the research presented in this publication in line with the journal's policy. As it cannot be established whether the article complies with the journal's policies on ethical approval, the Editor has decided to issue this expression of concern to alert readers when they are evaluating this article.