The present invention provides a pharmaceutical composition for use in a dosage form for oral administration to a patient. The composition expands upon contact with gastric fluid and promotes retention of the dosage form in the patient's stomach for a prolonged period of time. The present invention further provides pharmaceutical dosage forms containing an active ingredient, and the pharmaceutical composition. The forms are adapted for immediate or controlled release of the active ingredient. The dosage forms may be used advantageously in the treatment of Parkinson's disease with levodopa and hyperactivity and attention deficit disorder with methylphenidate.