Volatile Anesthetic Compositions and Methods of Use

Abstract

The present invention provides methods for reducing pain in a subject in need thereof by delivering a volatile anesthetic in a solution or an emulsion that can additionally include an extractive solvent in an amount effective to reduce pain without substantially interfering with motor function. Chronic or acute pain may be treated, or the volatile anesthetic may be delivered as a regional anesthetic to a subject to anesthetize a portion of the subject prior to surgery. Dosing regimes including a one-time administration, continuous and/or periodic administration are contemplated.

1 - 323 . (canceled) 
     
     
         324 . A method for reducing pain in a subject in need thereof, the method comprising delivering to the subject by a route other than orally, intravenously or by inhalation, a volatile anesthetic dissolved in a solution in an amount effective to reduce pain, and wherein the solution further comprises an extractive solvent in an amount effective to reduce volatility of the volatile anesthetic, and wherein the solution is a component of an emulsion. 
     
     
         325 . The method of  claim 324 , wherein the extractive solvent is at least one selected from the group consisting of dimethyl sulfoxide (DMSO), dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone (NMP), dimethylisosorbide, ethanol, propanol, and isopropanol. 
     
     
         326 . The method of  claim 324 , wherein the volatile anesthetic is selected from the group consisting of isoflurane, halothane, enflurane, sevoflurane, desflurane, methoxyflurane, xenon and mixtures thereof. 
     
     
         327 . The method of  claim 324 , wherein the volatile anesthetic is delivered by at least one route from the group selected from intrathecally, epidurally, transdermally, topically, mucosally, buccally, rectally, vaginally, intramuscularly, subcutaneously, by local skin infiltration, and in a nerve block procedure. 
     
     
         328 . The method of  claim 324 , wherein the subject is a human patient or an animal patient. 
     
     
         329 . A method for reducing pain in a subject in need thereof, the method comprising delivering to the subject by a route other than orally, intravenously or by inhalation, a volatile anesthetic emulsion. 
     
     
         330 . The method of  claim 329 , wherein the volatile anesthetic is selected from the group consisting of isoflurane, halothane, enflurane, sevoflurane, desflurane, methoxyflurane, xenon and mixtures thereof. 
     
     
         331 . A method for reducing pain in a subject in need thereof, the method comprising delivering to the subject by a route other than orally, intravenously or by inhalation, a liposome suspension comprising a volatile anesthetic in an amount effective to reduce pain. 
     
     
         332 . The method of  claim 331 , wherein the volatile anesthetic is selected from the group consisting of isoflurane, halothane, enflurane, sevoflurane, desflurane, methoxyflurane, xenon and mixtures thereof. 
     
     
         333 . A method for reducing pain in a subject in need thereof, the method comprising delivering to the subject by a route other than orally, intravenously or by inhalation, a volatile anesthetic dissolved in a solution in an amount effective to reduce pain, and wherein the solution further comprises an extractive solvent in an amount effective to reduce volatility of the volatile anesthetic, and wherein the composition further comprises a solubilizing agent. 
     
     
         334 . The method of  claim 333 , wherein the volatile anesthetic is selected from the group consisting of isoflurane, halothane, enflurane, sevoflurane, desflurane, methoxyflurane, xenon and mixtures thereof. 
     
     
         335 . A method for reducing pain in a subject in need thereof, the method comprising delivering to the subject by a route other than orally, intravenously or by inhalation, a microdroplet suspension comprising a sphere of a volatile anesthetic surrounded by a stabilizing layer of lipid in an amount effective to reduce pain. 
     
     
         336 . The method of  claim 335 , wherein the volatile anesthetic is selected from the group consisting of isoflurane, halothane, enflurane, sevoflurane, desflurane, methoxyflurane, xenon and mixtures thereof. 
     
     
         337 . A pharmaceutically acceptable composition comprising a metered amount of a volatile anesthetic dissolved in an aqueous solution in an amount effective to reduce pain, and wherein the solution further comprises an extractive solvent in an amount effective to reduce volatility of the volatile anesthetic, and wherein the solution is a component of an emulsion, and wherein the composition further comprises a pharmaceutically acceptable excipient. 
     
     
         338 . The composition of  claim 337 , wherein the volatile anesthetic is selected from the group consisting of isoflurane, halothane, enflurane, sevoflurane, desflurane, methoxyflurane, xenon and mixtures thereof. 
     
     
         339 . A pharmaceutically acceptable composition comprising a metered amount of a volatile anesthetic emulsion, wherein the composition further comprises a pharmaceutically acceptable excipient. 
     
     
         340 . The composition of  claim 339 , wherein the volatile anesthetic is selected from the group consisting of isoflurane, halothane, enflurane, sevoflurane, desflurane, methoxyflurane, xenon and mixtures thereof. 
     
     
         341 . A pharmaceutically acceptable composition comprising a metered amount of a liposome suspension comprising a volatile anesthetic; wherein the composition further comprises a pharmaceutically acceptable excipient. 
     
     
         342 . The composition of  claim 341 , wherein the volatile anesthetic is selected from the group consisting of isoflurane, halothane, enflurane, sevoflurane, desflurane, methoxyflurane, xenon and mixtures thereof. 
     
     
         343 . A pharmaceutically acceptable composition comprising a metered amount of a volatile anesthetic dissolved in a solution in an amount effective to reduce pain, and wherein the solution further comprises an extractive solvent in an amount effective to reduce volatility of the volatile anesthetic, and wherein the composition further comprises a solubilizing agent and wherein the composition further comprises a pharmaceutically acceptable excipient. 
     
     
         344 . The composition of  claim 343 , wherein the volatile anesthetic is selected from the group consisting of isoflurane, halothane, enflurane, sevoflurane, desflurane, methoxyflurane, xenon and mixtures thereof. 
     
     
         345 . A pharmaceutically acceptable composition comprising a metered amount of a microdroplet suspension comprising a microdroplet suspension comprising a sphere of a volatile anesthetic surrounded by a stabilizing layer of a phospholipid; wherein the composition further comprises a pharmaceutically acceptable excipient. 
     
     
         346 . The composition of  claim 345 , wherein the volatile anesthetic is selected from the group consisting of isoflurane, halothane, enflurane, sevoflurane, desflurane, methoxyflurane, xenon and mixtures thereof.