Controlled release oral dosage formulations containing calcium channel blocker and processes for preparation thereof, are provided for once a day treatment. The active agent is preferably a dihydropyridine calcium channel blocker, such as nisoldipine. In one embodiment, the formulation provides controlled release of micronized nisoldipine with one or more pH independent release controlling polymers. The controlled release matrix formulation is advantageous and can be prepared by a simple, economically viable process as compared to complex core-coat prior-art versions.
