Indeed this method of administration can be utilized for the implementation of insulin. I actually started to look into that and read something about how it is done. I will go back through my notes and get back to you
Insulin is destroyed by enzymes in the mouth so RapiMed wouldn't work for insulin.
Closest thing for oral insulin is ORMP and their product in early trials; and that's a capsule that will have to protect insulin from being destroyed by stomach acid and digestive enzymes. It will be interesting to see how it holds up and how they dose units of insulin with a capsule.