Patent ID: 6214300
Filing Date: 2001-04-10
Classification: A61K,B01F,B01J

Abstract:
A microencapsulation device which comprises:a chamber having a first and second region along a length of the chamber, wherein;a filter situated substantially perpendicular to the chamber length, wherein the first region is below and adjacent to the filter and the second region is above and adjacent to the filter, the filter having a maximum pore size of between 1 and 100 microns;a first inlet port in fluid communication with the first region, wherein a first fluid is introduced into the first region below the filter;a second inlet port in fluid communication with the second region wherein a second fluid is introduced into the second region, wherein the second fluid is immiscible with the first fluid, whereby a quiescent interface between the first and second fluids is formed at the filter;an auxiliary port in communication with the first or second region, wherein fluid is introduced into or withdrawn from the first or second region;a first plunger slidably movable along the length of the chamber below the filter, wherein when the first plunger is moved toward the second region the quiescent interface moves upward into the second region away from the filter while maintaining fluid shear forces at the interface of less than 100 dynes/cm.sup.2, said interface is formed between an aqueous solution and a hydrocarbon solution having a dissolved membrane-forming substance therein, said membrane-forming substance being substantially insoluble in water, whereby surface tension and interfacial coacervation at the interface cause formation of liquid microcapsules surrounded by a membrane;a second plunger slidably movable along the length of the chamber above the filter, wherein the movement of the second plunger moves fluid in the direction of movement of the second plunger, such that when the second plunger is moved toward the first region fluid will move from the second region through the filter into the first region; anda first electrode and a second electrode situated on opposing ends of the first or second region to provide an electric field across the second region, whereby microcapsules suspended in the coating fluid are electrostatically coated.