F.U.B.A.R.
Bluelight Crew
Apparently nasal administration of morphine is piss poor compared to oral. Rectal is even better than oral.
I think I'm losing the plot here, but from what I understand with morphine (discounting IV), rectal administration has the highest bioavailabity, followed by oral then nasal.
But as we're talking about methadone here, this is probably irrelevant.