Crystalline form of sucralose, and method for producing it

Abstract

A crystalline form of sucralose, and a method of making it. The method involves continuously crystallizing sucralose from an aqueous solution by a process providing continuous removal and recirculation of the vessel contents, and providing a long residence time for sucralose in the system. The crystals thus formed are of a relatively low length/diameter ratio, have an unsymmetrical shape, and exhibit good stability. The larger crystals in particular are tapered as compared to the rod-like larger crystals in prior art product.

1 - 16 . (canceled)  
     
     
         17 . A composition comprising stable sucralose crystals, each of at least a portion of the sucralose crystals comprising a plurality of crystalline sucralose domains.  
     
     
         18 . The composition of  claim 17  having an angle of repose of less than 42 degrees.  
     
     
         19 . The composition of  claim 17  wherein each of the sucralose crystals has a crystal length, the crystal length being the longest dimension thereof, and a greatest crystal width measured at right angles to the crystal length, wherein the ratio of the crystal length to the greatest crystal width is on average less than 6.  
     
     
         20 . The composition of  claim 17  wherein each of the sucralose crystals has a crystal length thereof, the crystal length being the longest dimension, and a greatest crystal width measured at right angles to the crystal length, wherein the ratio of the crystal length to the greatest crystal width is on average less than 4.  
     
     
         21 . The composition of  claim 17  wherein 90 wt. % of the sample has a particle size less than from about 30 μm to about 150 μm, and 10 wt. % has a particle size less than from about 3 μm to about 40 μm.  
     
     
         22 . The composition of  claim 17  wherein the sucralose crystals have a moisture content from about 0.2% to about 10%.  
     
     
         23 . A composition comprising stable sucralose crystals, wherein the sucralose crystals are generally tapered.  
     
     
         24 . The composition of  claim 23  wherein each of the sucralose crystals has a crystal length, the crystal length being the longest dimension thereof, and a greatest crystal width measured at right angles to the crystal length, wherein the ratio of the crystal length to the greatest crystal width is on average less than 6.  
     
     
         25 . The composition of  claim 23  wherein each of the sucralose crystals has a crystal length, the crystal length being the longest dimension thereof, and a greatest crystal width measured at right angles to the crystal length, wherein the ratio of the crystal length to the greatest crystal width is on average less than 4.  
     
     
         26 . The composition of  claim 23  wherein 90 wt. % of the sample has a particle size less than from about 30 μm to about 150 μm, and 10 wt. % has a particle size less than from about 3 μm to about 40 μm.  
     
     
         27 . The composition of  claim 23  having an angle of repose of less than 42 degrees.  
     
     
         28 . The composition of  claim 23  wherein the sucralose crystals have a moisture content from about 0.2% to about 10%.  
     
     
         29 . Stable sucralose crystals prepared by a method comprising: 
 introducing a feed stream of sucralose solution into a system comprising a crystallization vessel, a heat exchanger, and a pump configured to recirculate the sucralose solution out of and back into the crystallizer vessel and through the heat exchanger:    causing sucralose crystals to form continuously in the system:    removing an output stream of sucralose solution including sucralose crystals from the system: and    continuously recirculating a part of the output stream including sucralose crystals to the crystallization vessel, and separating sucralose crystals from the remaining part of the output stream;    wherein the rates of introducing, removing, and recirculating are controlled so that sucralose passing through the system has, on average, a residence time in the system of at least four hours: and    drying the separated sucralose crystals at a drying temperature of about 85° F. or below.