Process for the controlled production of organic particles

Abstract

A process for the production of a microparticle or a nanoparticle of a chemical compound comprising the steps of providing a solution of said chemical compound in a first liquid; providing a second liquid in which said chemical compound is insoluble or substantially insoluble; combining said liquids in a region of high shear thereby causing formation of said particles; and isolating said particles of said compound. The processing time of a coacervation style process can be reduced and the yield can be substantially increased both by control of the precipitation step which allows for desolvation step to be dispensed with leading to significant process time reduction. The invention also provides a molecular mixing unit comprising an outer body defining a mixing zone; a shear means to provide shear liquid in said mixing zone; at least one fluid inlet means for a first liquid; at least one fluid inlet means for a second liquid and a fluid outlet means.

1 . A process for the production of a microparticle or a nanoparticle of a chemical compound comprising:
 (a) providing a solution of said chemical compound in a first liquid   (b) providing a second liquid in which said chemical compound is insoluble or substantially insoluble;   (c) combining said liquids in a region of high shear thereby causing formation of said particles; and   (d) isolating said particles of said compound.   
     
     
         2 . A process according to  claim 1  wherein said step (c) comprises injecting said liquids into a mixing zone comprising a shear means which imparts high shear to said liquids. 
     
     
         3 . A process according to  claim 2  wherein said liquids are injected into said mixing zone directly onto said shear means. 
     
     
         4 . A process according to  claim 3  wherein said shear means is rotating in said mixing region to impart high shear to said injected liquids. 
     
     
         5 . A process according to  claim 4  wherein said shear means is rotating at a speed of from about 1,000 rpm to about 10,000 rpm. 
     
     
         6 . A process according to  claim 2  wherein said first liquid is water. 
     
     
         7 . A process according to  claim 6  wherein said second liquid is ethanol. 
     
     
         8 . A process according to  claim 7  wherein said ratio of said first liquid to said second liquid injected into said mixing region is 0.8:1 to 1.2:1. 
     
     
         9 . A process according to  claim 4  wherein said shearing means is a molecular packing. 
     
     
         10 . A process according to  claim 9  wherein said molecular packing is a substantially cylindrical shear means formed from at least one mesh layer. 
     
     
         11 . A process according to  claim 10  wherein said molecular packing is formed from a plurality of overlapping mesh layers. 
     
     
         12 . A process according to  claim 10  wherein said molecular packing is formed by rolling a mesh to form a substantially cylindrical shear means wherein said cylindrical section is defined by sides with a plurality of overlapping mesh layers. 
     
     
         13 . A process according to  claim 10  wherein said mesh has a mesh size of 0.5 to 3.0 mm. 
     
     
         14 . A process according to  claim 13  wherein said mesh has a mesh size of 0.1 to 0.5 mm. 
     
     
         15 . A process according to  claim 10  wherein said mesh has a porosity of greater than 90%. 
     
     
         16 . A process according to  claim 15  wherein said mesh has a porosity of greater than 95%. 
     
     
         17 . A process according to  claim 2  wherein each of said liquids are injected into said mixing zone through a plurality of inlets. 
     
     
         18 . A process according to  claim 17  wherein each inlet for said first liquid is located within said mixing region no further than 15 degree of arc from an inlet for said second liquid. 
     
     
         19 . A process according to  claim 3  wherein said injection velocity of said injected liquids is greater than 1 ms −1 . 
     
     
         20 . A molecular mixing unit comprising:
 (a) an outer body defining a mixing zone;   (b) a shear means to provide shear liquid in said mixing zone;   (c) at least one fluid inlet means for a first liquid;   (d) at least one fluid inlet means for a second liquid;   (e) a fluid outlet means.