Emulsion formulations for hydrophilic active agents

Abstract

This invention discloses emulsion formulations comprising an aqueous carrier and the following components: triglyceride, cholesterol, phospholipid, at least one charged lipid, at least one hydrophilic biologically active molecule and, optionally, cholesteryl ester, and/or apoprotein; methods of preparing these emulsions; and the use of these emulsions as vehicles for the delivery of hydrophilic biologically active molecules to cells.

1 . A synthetic emulsion formulation comprising triglycerides, cholesterol, phospholipids, at least one charged lipid, at least one hydrophilic biologically active molecule and an aqueous carrier.  
     
     
         2 . The emulsion formulation of  claim 1 , further comprising cholesteryl esters.  
     
     
         3 . The emulsion formulation of  claim 1 , further comprising at least one apoprotein.  
     
     
         4 . The emulsion formulation of  claim 2 , further comprising at least one apoprotein.  
     
     
         5 . The emulsion formulations of claims  1 - 4 , wherein the charged lipid is an anionic lipid and the hydrophilic biologically active molecule is positively charged.  
     
     
         6 . The emulsion formulations of claims  1 - 4 , wherein the charged lipid is a cationic lipid and the hydrophilic biologically active molecule is negatively charged.  
     
     
         7 . The emulsion formulation of  claim 6 , wherein the hydrophilic biologically active molecule is a nucleic acid molecule.  
     
     
         8 . The emulsion formulation of  claim 7 , wherein the nucleic acid molecule is a gene.  
     
     
         9 . An emulsion formulation produced by 
 (a) mixing a hydrophobic complex of at least one charged lipid and at least one hydrophilic biologically active molecule with triglyceride, cholesterol and phospholipid in an organic solvent;    (b) removing said solvent to leave a lipid film; and    (c) resuspending said film in aqueous carrier to produce the emulsion formulation.    
     
     
         10 . The emulsion formulation of  claim 9 , wherein the weight ratio of biologically active molecule to the sum of triglyceride, cholesterol and phospholipid to be mixed in step (a) is about 1:50 to about 1:400.  
     
     
         11 . The emulsion formulation of  claim 9 , wherein the components of step (a) are further mixed with cholesteryl esters.  
     
     
         12 . The emulsion formulation of  claim 11 , wherein the weight ratio of biologically active molecule to the sum of triglyceride, cholesterol, cholesteryl ester, and phospholipid in step (a) is about 1:50 to about 1:400.  
     
     
         13 . The emulsion formulations of claims  9  or  11 , wherein the components of step (a) are further mixed with at least one water-insoluble apoprotein.  
     
     
         14 . The emulsion formulations of claims  9  or  11 , wherein the emulsion formulation produced in step (c) is further mixed with at least one water-soluble apoprotein.  
     
     
         15 . A method of producing an emulsion comprising: at least one charged lipid, at least one hydrophilic biologically active molecule, triglyceride, cholesterol, phospholipid and an aqueous carrier, said method comprising: 
 (a) mixing a hydrophobic complex of charged lipid and hydrophilic biologically active molecule with triglyceride, cholesterol and phospholipid in an organic solvent;    (b) removing the organic solvent to leave a lipid film; and    (c) suspending said film in an aqueous buffer to produce the emulsion.    
     
     
         16 . A method for producing an emulsion comprising at least one charged lipid, at least one hydrophilic biologically active molecule, triglyceride, cholesterol, phospholipid an aqueous carrier and optionally apoprotein, said method comprising: 
 (a) extracting native lipoprotein with an organic solvent;    (b) mixing the extracted lipoprotein components with a hydrophobic complex of charged lipid and hydrophilic biologically active molecule in an organic solvent;    (c) removing the organic solvent to produce a lipid or a lipid:protein film; and    (d) adding aqueous carrier to the film to produce the emulsion.    
     
     
         17 . A lipid film capable of forming-an emulsion formulation upon suspension in an aqueous carrier, said lipid film comprising triglyceride, cholesterol phospholipid, at least one charged lipid and at least one hydrophilic biologically active molecule.  
     
     
         18 . The lipid film of  claim 17 , further comprising cholesteryl esters.  
     
     
         19 . A lipid:protein film capable of forming an emulsion formulation upon suspension in an aqueous carrier, said film comprising triglyceride, cholesterol, phospholipid, at least one charged lipid, at least one hydrophilic biologically active molecule, and at least one-water-insoluble apoprotein.  
     
     
         20 . The lipid:protein film of  claim 19 , said film further comprising cholesteryl esters.  
     
     
         21 . A method of producing a lipid film having at least one charged lipid, at least one hydrophilic biologically active molecule, cholesterol, triglyceride and phospholipid, said method comprising: 
 (a) mixing a hydrophobic complex of charged lipid and hydrophilic biologically active molecule with triglyceride, phospholipid and cholesterol in an organic solvent; and    (b) removing said solvent to leave the lipid film.    
     
     
         22 . The method according to  claim 21 , wherein the hydrophobic complex in step (a) is also mixed with cholesteryl ester.  
     
     
         23 . The method according to  claim 21 , wherein the hydrophobic complex in step (a) is also mixed with at least one apoprotein.  
     
     
         24 . A method for delivering a hydrophilic biologically active molecule to cells, said method comprising exposing the cells to the emulsion formulations of any one claims  1 - 3  thereby facilitating the delivery of the biologically active molecule to the cells.  
     
     
         25 . The method for delivering a biologically active molecule to cells according to  claim 24 , wherein the cells are exposed to the emulsion formulations in vivo by administering the emulsion formulations to an animal in an amount effective to facilitate the delivery of the biologically active molecule to the cells of the animal.  
     
     
         26 . The method of  claim 25 , wherein the biologically active molecule is a nucleic acid molecule.  
     
     
         27 . The method of  claim 24 , wherein the cells are exposed to the emulsion formulations in vitro.  
     
     
         28 . The method of  claim 27 , wherein the biologically active molecule is a nucleic acid molecule.