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 treating pulmonary hypertension in a human subject comprising administering to the human subject a solid oral dosage form comprising: (a) an osmotically-active drug core comprising treprostinil or a pharmaceutically acceptable salt thereof; and (b) a semi-permeable membrane surrounding the osmotically-active drug core, wherein the semi-permeable membrane comprises at least one opening having a diameter from 100 μm to 800 μm to permit osmotic release of the treprostinil or its pharmaceutically acceptable salt from the osmotically-active drug core, wherein the administration provides a therapeutically effective plasma concentration of treprostinil in the human subject. 
     
     
         20 . The method of  claim 19 , wherein the therapeutically effective plasma concentration of treprostinil in the human subject has a T max  of 2 hours to 8 hours. 
     
     
         21 . The method of  claim 20 , wherein the therapeutically effective plasma concentration of treprostinil in the human subject has a C max  of 0.5 ng/ml to 2 ng/ml. 
     
     
         22 . The method of  claim 21 , wherein the therapeutically effective plasma concentration of treprostinil in the human subject has a C min  of 0.1 ng/ml to 0.2 ng/ml. 
     
     
         23 . The method of  claim 19 , wherein the (a) osmotically-active drug core further comprises at least one release-enhancing agent. 
     
     
         24 . The method of  claim 23 , wherein the at least one release-enhancing agent is a wicking agent selected from the group consisting of high HLB surfactants, ionic surfactants, and non-swelling hydrophilic polymers. 
     
     
         25 . The method of  claim 23 , wherein the at least one release-enhancing agent is a complexing agent selected from the group consisting of polyvinyl pyrrolidone, cyclodextrins, and non-ionic surface active agents. 
     
     
         26 . The method of  claim 23 , wherein the at least one release-enhancing agent is a micelle forming agent selected from the group consisting of poly(ethylene oxide) modified sorbitan monoesters, fatty acid sorbitan esters, sodium lauryl sulfate, and sodium docusate. 
     
     
         27 . The method of  claim 23 , wherein the release-enhancing agent is sodium lauryl sulfate.