Great question, Fady!
I have some experience with filing combination drug product in the EU. One instance, in particular, that comes to mind is a topical gel for scarring that was accompanied by a massaging applicator. The purpose of the applicator was to penetrate the scar tissue with the gel in order to achieve the greatest effect to minimize scarring. It was difficult to choose a directive because it fell into two categories: a class one, non-sterile device and a gel with active product. Since the applicator was not the primary mode of action, it could not be filed as a medical device.