Dosage form comprising means for changing drug delivery shape

Abstract

A dosage form is disclosed comprising means for delivering essentially a total dose of drug.

We claim:  
     
         1 . A dosage form for delivering a drug to a patient in need of the drug, wherein the dosage form comprises: an orally administrable therapeutic composition comprising a dose of drug and a pharmaceutically acceptable polymer carrier for transporting the drug from the dosage form; a membrane that surrounds the therapeutic composition, which membrane comprises a polymer permeable to the passage of fluid, a plasticizer, a surfactant, and a binder; and an exit in the membrane for delivering the drug at a sustained-release rate over an extended time.  
     
     
         2 . The dosage form for delivering the drug according to  claim 1 , wherein the membrane changes shape during the operation of the dosage form.  
     
     
         3 . A dosage form for delivering the drug according to  claim 1 , wherein the binder is compatible with and binds the polymer, plasticizer, and surfactant into the membrane.  
     
     
         4 . The dosage form for delivering a drug to a patient in need of the drug, wherein the dosage form comprises: an orally administrable therapeutic composition comprising a dose of drug and a pharmaceutically acceptable polymer carrier for transporting the drug from the dosage form; a displacement composition comprising a polymer that expands in the presence of an aqueous fluid and thereby pushes the therapeutic composition from the dosage form; a membrane that surrounds the therapeutic composition and the displacement composition, which membrane comprises a polymer permeable to the passage of an aqueous fluid, a plasticizer, a surfactant, and a binder; and an exit in the membrane for delivering the drug at a sustained-release rate over an extended time.  
     
     
         5 . The dosage form for delivering the drug according to  claim 3 , wherein the membrane possesses a surface that faces the therapeutic composition and the displacement composition and a surface that faces the patient and carries thereon a dose of drug.