A lot of people deal with separation anxiety by giving their dogs something to keep 'em occupied like suggested above.
I've seen another that got the dog used to the idea of you leaving. You do your normal routine by putting your jacket on (or what have you), walk out the front door, and come back in less than a minute later. Repeat as necessary to get the dog used to you leaving. You also have to make leaving and coming in impersonal, as difficult as it may be not to say goodbye, or pet them as soon as you come in.
But if you really don't have time for that, there are some calming aids. And they're completely safe. The one that caught my eye was actually like a glade plug-in! I've got the link to it right here, if you'd like to check it out...
Stress Control: Comfort ZoneŽ Plug-In for Dogs
I'm not sure if that'll work, but there are a few other calming aids on that site. I hope everything goes well! Happy travels!