You might want to google sublingual medication. I was surprised at what came up. There are a good number of meds given in this way. For example:
http://www.nlm.nih.gov/medlineplus/d...r/a605002.html

And this one too:
http://bja.oxfordjournals.org/cgi/co...tract/55/8/761

Found this last one (above) interesting just from a clinical standpoint.

This one I didn't know about either. They give allergy meds this way too and it works better than taking them orally.

http://www.webmd.com/allergies/news/...-without-shots

One study I came across stated that giving meds this way even fairly large molecules are absorbed. They didn't give many examples and the article was quite technical really. And it focused on the buccal mucosa as the delivery system....
http://www.ualberta.ca/~csps/JPPS1(1...ccalreview.htm

I'd like to see more info specifically about B-12. I've been hearing about the sublingual form for quite sometime. Just wish I could remember *where* I heard it or saw it!

I *did* find an article that stated: ...no difference in efficacy between the two methods of vitamin complex delivery.

http://www.medscape.com/medline/abstract/17109579

A very interesting discussion! Thank you!