Osmotic drug delivery system

Abstract

An oral osmotic pharmaceutical delivery system comprises a highly water-soluble drug exhibiting an erratic or an incomplete release profile when formulated in an elementary osmotic pump delivery system and at least one release enhancing agent.

1 - 18 . (canceled) 
     
     
         19 . A method of making an oral osmotic pharmaceutical dosage form of treprostinil, comprising mixing a release enhancing agent with a pharmaceutically acceptable salt of treprostinil. 
     
     
         20 . The method of  claim 19 , wherein the pharmaceutically acceptable salt of treprostinil is treprostinil diethanolamine. 
     
     
         21 . The method of  claim 19 , wherein the release enhancing agent is sodium lauryl sulfate. 
     
     
         22 . The method of  claim 20 , wherein the release enhancing agent is sodium lauryl sulfate. 
     
     
         23 . The method of  claim 19 , further comprising granulating a composition comprising the pharmaceutically acceptable salt of treprostinil. 
     
     
         24 . The method of  claim 23 , wherein said mixing is performed during the granulating. 
     
     
         25 . The method of  claim 23 , wherein said mixing is performed after the granulating. 
     
     
         26 . The method of  claim 19 , wherein said mixing comprising dissolving the pharmaceutically acceptable salt of treprostinil and the release enhancing agent in a solvent to form a solution and then drying a solution to form a solid mass. 
     
     
         27 . The method of  claim 26  further comprising milling the solid mass. 
     
     
         28 . The method of  claim 23 , further comprising blending granules formed during said granulating with one or more excipients. 
     
     
         29 . The method of  claim 23 , wherein the granulated composition further comprises one or more osmotic agents. 
     
     
         30 . The method of  claim 29 , wherein the one or more osmotic agents are selected from the group consisting of simple sugars, salts and low molecular weight hydrophilic polymers. 
     
     
         31 . The method of  claim 30 , wherein the simple sugars are selected from the group consisting of sucrose, xylitol, glucose and lactose. 
     
     
         32 . The method of  claim 30 , wherein the salts are selected from sodium chloride and potassium chloride. 
     
     
         33 . The method of  claim 30 , wherein the low molecular weight hydrophilic polymers are selected from the group consisting of cellulose ethers, maltodextrins, and cyclodextrins. 
     
     
         34 . The method of  claim 23 , further comprising forming from the granules formed during the granulation a dosage form selected from the group consisting of a tablet, a capsule or a pellet. 
     
     
         35 . The method of  claim 34 , wherein the dosage form is a tablet. 
     
     
         36 . The method of  claim 35  further comprising coating the tablet with a semipermeable membrane containing at least one plasticizer. 
     
     
         37 . The method of  claim 36 , wherein said coating comprises forming a coating solution by dissolving a coating polymer with the least one plasticizer in a solvent and applying the coating solution to the tablet. 
     
     
         38 . The method of  claim 36 , wherein the at least one plasticizer is selected from the group consisting of triethyl citrate (TEC), propylene glycol(PG), or mixtures thereof in ratios of TEC to PG ranging from 25:75 to 75:25; Tween 80, polyethylene glycols (PEGs); polyoxyethylene sorbitan esters, triacetin, diethyl phthalate, mineral oil, tributyl sebacate, and glycerol.