Adobe has published a document for interacting with Acrobat and/or Reader using VBA. I suspect that if an object is instantiated for the application and the document, it should be possible. I know that it's possible to populate a pdf form with Access data, so if one can interact like that, it should be possible to close a file and the app - I've just never tried. The data transfer has been covered in this forum before.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.