Welcome to Blue Light, you may get a better response to your question if you post in the Basic Drug Discussion sub-forum. The sub-forum you're in now is just for introductions so remains fairly inactive for people giving help advice on things such as synthacaine. It's more of a general chitty-chat place. Head over to BDS and create a new thread there, I'm sure you'll get some good answers in no time
Please DONT smoke this crap. First Synthacaine is not a drug, its an unknown mix of drug which probably contain local anesthesic in it and will makes it hard for you to breath if not causing respiratory depression. DO NOT SMOKE THIS.