You are correct, however, it was in the past administered *buccally *or sublingually. Works just fine. Too fine, in fact as the primary side effect was uterine rupture. Oopsie! *Again *with the titration issues! Mother Nature really is a bitch 
Here’s an old text which talks about buccal administration of pitocin, iffen you’re bored:
O’Sullivan, J. P.
The use of buccal “pitocin” for the induction of labour.
Irish Journal of Medical Science (1926-1967)
Volume 40, Number 2, 67-74, DOI: 10.1007/BF02943825