From that description, I'm assuming you've already read
Homunculus,
Ultra Heaven,
Eden and
SOIL, but are looking for more. If you haven't, any of those four fit what you're looking for nicely.
I haven't come across much dystopian stuff myself that isn't just post-apocalyptic (or borderline so), satirical or dwelled on too much, outside of a few very well-known ones.
Ikigami has a fairly standard dystopian set-up where Japan establishes a very questionable death-roulette system. It's broken up into several "random people find out they're about to die" arcs with an overarching plot. No scifi elements though.
Scientia is a reverse-dystopia, featuring a different take on a lot of standard "scifi dystopia" concepts.