Claims for Patent: 5,252,338

Summary for Patent: 5,252,338

Title:	Therapy delayed
Abstract:	A dosage form is disclosed comprising means for delaying the delivery of drug from the dosage form following the administration of the dosage form to a patient in need of drug therapy.
Inventor(s):	Jao; Frank (San Jose, CA), Wong; Patrick S. L. (Palo Alto, CA), Huynh; Hoa T. (Fremont, CA), McChesney; Kathy (Cupertino, CA), Wat; Pamela K. (Santa Clara, CA)
Assignee:	Alza Corporation (Palo Alto, CA)
Application Number:	07/971,011
Patent Claims:	1. A method for producing a delayed therapeutic effect of thirty minutes to seven hours in a patient in need of therapy, wherein the method comprises: (a) admitting into the gastrointestinal tract of a patient a dosage form comprising: (1) a drug composition comprising 0.05 mg to 1.5 g of a drug, and a pharmaceutically acceptable polymer comprising a molecular weight up to 1,000,000; (2) a push composition that imbibes fluid and expands, whereby the push composition pushes the drug composition from the dosage form; (3) a wall that surrounds the drug and push compositions, said wall comprising a semipermeable polymer permeable to the passage of fluid and up to 85 wt. % of a different polymer comprising a molecular weight up to 4,000,000 molecular weight for slowing the rate of fluid passage through the semipermeable wall; (4) at least one exit means in the semipermeable wall for delivering the drug from the dosage form; and wherein the dosage form is characterized by: (5) a subcoat for the delayed-delivery of the drug, which subcoat comprises a hydroxyalkylcellulose polymer comprising a molecular weight up to 4,000,000 that surrounds the drug and the composition on the inside surface of the semipermeable wall; (b) imbibing fluid into the dosage form to provide a delayed drug delivery of thirty minutes up to seven hours b the polymer in the drug composition, the polymer in the semipermeable wall and the polymer in the subcoat operation operating together for delaying the drug delivery; and, (c) administering the drug at a delayed time to the patient in need of drug therapy.