Tandospiaine antidepressive therapy

An osmotic dosage form for administering tandospirone to a patient in need of tandospirone therapy, wherein the dosage form comprises:

• (a) a wall comprising a member selected from the group consisting of cellulose acetate, cellulose diacetate, and cellulose triacetate, which wall forms:
• (b) an internal compartment;
• (c) at least one exit passageway in the wall that connects the exterior of the dosage form with the compartment;
• (d) a push composition in the compartment comprising a composition that, in the presence of fluid that enters the compartment, increases in dimensions and thereby occupies space in the compartment;
• and wherein the osmotic dosage form is characterized by:
• (e) a tandospirone composition comprising 1 mg to 750 mg of tandospirone and a polyethylene oxide polymer comprising a 190,000 to 210,000 molecular weight pressed into a layer that provides a dispensable tandospirone composition for administering, when the dosage form is in operation, to the patient in need of tandospirone therapy at a controlled rate over a period up to thirty hours.