Right now the time release vitamin C (which contains fillers) is my only option to sleep; ascorbic acid doesn't help the same way.
Why you think it is that way? Could it be that by sustained release you maintain higher serum vitamin C longer throughout sleep, which drops very fast if taken at the same amount of regular vitamin C? However, having higher levels maintained for longer could also be accomplished with higher doses of ascorbic acid powder. I would experiment.