Oral Morphine has very low bioavailability, I think only 20% of a dose reaches the brain after first pass metabolism. I don't know the BA of insuflating morphine I'm guessing it's higher. Plugging it might be better too.
Scrape off the extended release layer (outer shell) crush to a fine powder and snort it all thats what id do. Or if uve got a syringe add some water to the crushed up morphine, mix it, suck it up into the syringe, insert the syringe into ur anus and inject while lying on ur stomach. Make sure u remove the needle lol.
The best / only way to take morphine is by IV but I wouldn't encourage that at all!