You can add security but it can not prevent saving the PDF.
In fact there are very few ways to prevent any file on a system from being saved. The ability to save a file at another location is a basic requirement for backing up a system.
Further, PDFs are downloaded to your local unit before viewing. So there is at least a temporary file created on your local system.
But there are other ways to control the distribution of the PDF. You can create a security policy, only allow trusted personnel to have access to the PDF by password or a digital certificate, and you can get a LiveCycle Policy Server to define authorized viewers and other restrictions. The LiveCycle Policy Server also maintains an audit trail for the policies, documents and users.
LiveCycle Rights Management ES2 page has more information.