Method of purification of polymeric medical device materials using continuous soxhlet extraction

Abstract

A process for removing contaminants and/or leachables from polymeric materials useful in the manufacture of biocompatible medical devices such as intraocular lenses, corneal inlays and contact lenses using continuous soxhlet extraction.

1 . A method of continuous soxhlet extraction for the purification of polymeric materials comprising: 
 assembling a flask, an extractor with a liquid arm dimensioned to enable continuous solvent flow and a condenser;    placing polymeric materials in said extractor and solvent in said flask; and    heating said solvent to create a flow of said solvent through said condenser, extractor and flask for purification of said polymeric materials.    
     
     
         2 . The method of  claim 1  wherein said condenser is cooled by the flow of a contained fluid.  
     
     
         3 . The method of  claim 1  wherein said condenser is cooled by the flow of contained water.  
     
     
         4 . The method of  claim 1  wherein said extractor is a soxhlet extractor.  
     
     
         5 . A method of continuous soxhlet extraction for the purification of polymeric materials comprising: 
 assembling a flask, an extractor with a liquid arm and adjustable valves to enable continuous solvent flow and a condenser;    placing polymeric materials in said extractor and solvent in said flask; and    heating said solvent to create a flow of said solvent through said condenser, extractor and flask for purification of said polymeric materials.    
     
     
         6 . The method of  claim 1  wherein said polymeric materials form medical devices.  
     
     
         7 . The method of  claim 1  wherein said polymeric materials form medical devices selected from the group consisting of contact lenses, corneal inlays, corneal rings, intraocular lenses, keratoprostheses and capsular bag extension rings.  
     
     
         8 . The method of  claim 1  wherein said polymeric materials are selected from the group consisting of hydrophobic acrylics, hydrophilic acrylics and silicone-based polymers.  
     
     
         9 . The method of  claim 1  wherein said polymeric materials are placed within a glass or cellulose thimble within said extractor.  
     
     
         10 . The method of  claim 1  wherein said polymeric materials are placed within a glass or cellulose thimble with a sintered glass filter in the bottom of said thimble.  
     
     
         11 . The method of  claim 1  wherein said solvent is selected from the group consisting of isopropanol, ethanol, water, tetrahydrofuran and toluene.  
     
     
         12 . A method of using medical devices purified using the method of  claim 5  comprising: 
 making an incision in the cornea of an eye; and    implanting said medical device in the form of a corneal inlay.    
     
     
         13 . A method of using medical devices purified using the method of  claim 5  comprising: 
 placing said medical device in the form of a contact lens on the cornea of an eye.    
     
     
         14 . A method of using medical devices purified using the method of  claim 5  comprising: 
 creating an incision in an eye; and    implanting said medical device in the form of an intraocular lens within an anterior chamber or posterior chamber of said eye.    
     
     
         15 . A method of using medical devices purified using the method of  claim 5  comprising: 
 creating an incision in an eye;    removing a lens from a lens capsule within said eye and implanting said medical device in the form of an intraocular lens within an anterior chamber, posterior chamber or lens capsule of said eye.    
     
     
         16 . The method of  claim 5  wherein said extractor is a gregar extractor.