Inputting of metadata in file for itunes import

Hi,

i am using Calibre 0.8.46 for Mac.
I opened some pdfs in Calibre and changed the metadata incl. covers and so on. I clicked on "Saved on hard drive" and imported these new created folders into itunes. But in itunes all new metadata is dissapeared without a trace. Nothing left?!?!?

Can someone please explain to me how to include or save all the metadata in the files so that i am able to import the files into itunes?

Thanks for a short feedback

regards
Arti