Have you taken a look at the MDSAP Audit Procedures and Forms
available on the FDA website?
This might be a good starting point.
Has anyody a best practice how to establish an internal audit program for MDSAP efficient an deffective? I don't want to add too much additonal ressources for internal auditing
Always remember that your internal audit program should have value to you. It should NOT be just a compliance exercise.
When planning your program, ask yourself: will this help drive improvement? In otherwords, is it effective at spotting non-conformances and opportunities for improvement?