The punishment would depend on which Judge you saw, among other things, I don't think anyone can give you a definitive punishment you will receive for x amount of diazepam tablets. A quick search on google tells me that diazepam is a Schedule IV drug in the Philippines, what this means for exact legal consequences I am not sure, but upon looking at other Schedule IV drugs in the Philippines it is clearly a prescription only drug. I would guess it is a safe bet that you do NOT want to get caught with them, I doubt Fillipino dungeons are a lot of fun.
I am closing this because I don't see the potential for discussion. Diazepam is illegal in the Philippines without a description and the punishment will vary depending on circumstances but is almost certain to be severe by Western standards.
