Abstract: The present invention refers to a tablet-shaped osmotic release system providing, in a controlled way, active principles which solubility depends on the pH of the medium, simultaneously providing appropriate solubilization throughout the gastrointestinal tract. The pharmaceutical osmotic release system comprises of a pharmaceutical layer, which contains at least one active principle in a solid solution, a propelling layer, which contains at least one osmopolymer and at least one osmoagent, a semipermeable coating involving both layers, and at least one orifice in the semipermeable coating at the side of the pharmaceutical layer.