Do you mean OxyContin?
OxyContin is easy to identify. It has "OC" imprinted on one side and a number on the other side. The number is how many mg's of oxycodone are in it.. 10, 20, 40, 60 or 80.
I've never heard of Oxycodan, but it may be some generic form of Percocet if that's the actual name. As for ASA, I don't know what the fuck that means, but Percocet and all generic brand names of it contain something called Acetaminophen which is abbreviated APAP. It should contain 5mg of oxycodone if so. You don't want to snort APAP. Eat it/them if it is this.
As for it being OxyContin, I would say inject it and screw the health risk. After shooting it myself, I can't imagine why anyone bothers using it any other way. It's a completely different (and MUCH better) drug when injected. I have no idea how much to recommend if you're actually willing to screw yourself up to shoot it. I can take 40mgs in one shot followed by another 20mgs (hey, I use 50 unit needles!), but then again my tolerance is through the roof.
Most people would recommend snorting it. As far as I'm concerned it takes more oxycodone when snorted to get off than it would to just eat it.. say 30mgs snorted = 20mgs oral in my opinion. The only advantage is not having to wait 45-60 mins for it to work.