A dosage form comprising a gelatin capsule formed with a composite wall and containing a liquid, active agent formulation where the wall comprises a barrier layer formed over the external surface of the gelatin capsule, an expandable layer formed over the barrier layer and a semipermeable layer formed over the expandable layer is described. The dosage forms and methods provide for the conversion of standard gelatin, liquid formulation capsules into controlled, release dosage forms that permit the controlled release of the active agent into the environment of use over time.