Emulsion vehicle for poorly soluble drugs

Abstract

An emulsion of α-tocopherol, stabilized by biocompatible surfactants, as a vehicle or carrier for therapeutic drugs, which is substantially ethanol free and which can be administered to animals or humans various routes is disclosed. Also included in the emulsion is PEGylated vitamin E. PEGylated α-tocopherol includes polyethylene glycol subunits attached by a succinic acid diester at the ring hydroxyl of vitamin E and serves as a primary surfactant, stabilizer and secondary solvent in emulsions of α-tocopherol.

1 . A composition suitable for orally administering paclitaxel comprising: 
 paclitaxel; and    a pharmaceutically-acceptable, water-miscible solubilizer having the general structure: R1COOR2    wherein R1 is a derivative of d-α-tocopherol and R2 is a hydrophilic moiety.    
     
     
         2 . The composition according to  claim 1 , wherein the derivative of d-α-tocopherol is esterified by polyethylene glycol.  
     
     
         3 . The composition according to  claim 1 , wherein the solubilizer is esterified d-α-tocopherol acid succinate.  
     
     
         4 . The composition according to  claim 1 , wherein the solubilizer is d-α-tocopherol polyethylene glycol succinate (TPGS).  
     
     
         5 . The composition according to  claim 1 , further comprising a solvent.  
     
     
         6 . The composition according to  claim 5 , wherein the solvent is an alcohol.  
     
     
         7 . The composition according to  claim 5 , wherein the solvent is selected from the group consisting of ethanol and polyethylene glycol (PEG).  
     
     
         8 . The composition according to  claim 5 , wherein the weight ratio of the solubilizer to the solvent is between about 90:10 and 60:40.  
     
     
         9 . The composition according to  claim 5 , wherein the weight ratio of the solubilizer to the solvent is between about 80:20 and 70:30.  
     
     
         10 . The composition according to  claim 1 , further comprising an acidifying agent.  
     
     
         11 . The composition according to  claim 1 , wherein paclitaxel has a concentration in the composition between 0.1 and 20 mg/g.  
     
     
         12 . The composition according to  claim 1 , wherein paclitaxel has a concentration in the composition between 0.5 and 10 mg/g.  
     
     
         13 . The composition according to  claim 1 , wherein the composition is filled into a soft or hard gelatin capsule.  
     
     
         14 . The composition according to  claim 1 , wherein the composition is covered with a protective or sustained release coating.  
     
     
         15 . A method for orally administering paclitaxel to a host in need thereof comprising: 
 providing a pharmaceutical composition comprising paclitaxel and a pharmaceutically-acceptable, water-miscible solubilizer having the general structure: R1COOR2    wherein R1 is a derivative of d-α-tocopherol and R2 is a hydrophilic moiety; and    orally administering the pharmaceutical composition in a therapeutically effective amount to the host in need thereof.