Stable pharmaceutical formulations of methylnaltrexone

Abstract

Stable pharmaceutical compositions useful for administering methylnaltrexone are described, as are methods for making the same. Kits, including these pharmaceutical compositions, also are provided.

We claim: 
     
         1 - 315 . (canceled) 
     
     
         316 . A stable pharmaceutical preparation comprising methylnaltrexone, or a salt thereof, and a chelating agent, wherein the chelating agent is ethylenediaminetriacetic acid (EDTA) or a derivative thereof. 
     
     
         317 . The stable pharmaceutical preparation of  claim 316 , wherein the preparation comprises methylnaltrexone bromide. 
     
     
         318 . The stable pharmaceutical preparation of  claim 316 , wherein the EDTA derivative is edetate calcium disodium. 
     
     
         319 . The stable pharmaceutical preparation of  claim 316 , wherein the preparation is a solid formulation. 
     
     
         320 . The stable pharmaceutical preparation of  claim 319 , wherein the preparation is suitable for oral delivery. 
     
     
         321 . The stable pharmaceutical preparation of  claim 319 , wherein the preparation is delivered at a dose from about 0.1 to 30 mg/kg body weight per day. 
     
     
         322 . The stable pharmaceutical preparation of  claim 319 , wherein the preparation is delivered at a dose from about 1.0 to 3.0 mg/kg body weight per day. 
     
     
         323 . A method for treating an opioid-induced peripheral side effect comprising administering to a patient the stable pharmaceutical preparation of  claim 316  in an amount effective to treat the side effect. 
     
     
         324 . The method of  claim 323 , wherein the opioid induced peripheral side effect is constipation. 
     
     
         325 . A stable pharmaceutical preparation comprising a solution of methylnaltrexone or a salt thereof and at least one methylnaltrexone degradation inhibiting agent selected from the group consisting of a chelating agent, a buffering agent, an antioxidant, and combinations thereof; wherein the solution has a pH ranging from 2 to 6. 
     
     
         326 . The stable pharmaceutical preparation of  claim 325 , wherein the preparation comprises a solution of methylnaltrexone bromide. 
     
     
         327 . The stable pharmaceutical preparation of  claim 325 , wherein the chelating agent is ethylenediaminetriacetic acid (EDTA) or a derivative thereof. 
     
     
         328 . The stable pharmaceutical preparation of  claim 327 , wherein the EDTA derivative is edetate calcium disodium.