PURPOSE: A new microencapsulation method called the "solvent exchange method" was developed using a dual microdispenser system. The objective of this research is to demonstrate the new method and understand how the microcapsule size is controlled by different instrumental parameters. METHOD: The solvent exchange method was carried out using a dual microdispenser system consisting of two ink-jet nozzles. Reservoir-type microcapsules were generated by collision of microdrops of an aqueous and a polymer solution and subsequent formation of polymer films at the interface between the two solutions. The prepared microcapsules were characterized by microscopic methods. RESULTS: The ink-jet nozzles produced drops of different sizes with high accuracy according to orifice size of a nozzle, flow rate of the jetted solutions, and forcing frequency of the piezoelectric transducers. In an individual microcapsule, an aqueous core was surrounded by a thin polymer membrane; thus, the size of the collected microcapsules was equivalent to that of single drops. CONCLUSIONS: The solvent exchange method based on a dual microdispenser system produces reservoir-type microcapsules in a homogeneous and predictable manner. Given the unique geometry of the microcapsules and mildness of the encapsulation process, this method is expected to provide a useful alternative to existing techniques in protein microencapsulation.
PURPOSE: A new microencapsulation method called the "solvent exchange method" was developed using a dual microdispenser system. The objective of this research is to demonstrate the new method and understand how the microcapsule size is controlled by different instrumental parameters. METHOD: The solvent exchange method was carried out using a dual microdispenser system consisting of two ink-jet nozzles. Reservoir-type microcapsules were generated by collision of microdrops of an aqueous and a polymer solution and subsequent formation of polymer films at the interface between the two solutions. The prepared microcapsules were characterized by microscopic methods. RESULTS: The ink-jet nozzles produced drops of different sizes with high accuracy according to orifice size of a nozzle, flow rate of the jetted solutions, and forcing frequency of the piezoelectric transducers. In an individual microcapsule, an aqueous core was surrounded by a thin polymer membrane; thus, the size of the collected microcapsules was equivalent to that of single drops. CONCLUSIONS: The solvent exchange method based on a dual microdispenser system produces reservoir-type microcapsules in a homogeneous and predictable manner. Given the unique geometry of the microcapsules and mildness of the encapsulation process, this method is expected to provide a useful alternative to existing techniques in protein microencapsulation.
Authors: Feng Wan; Morten Jonas Maltesen; Sune Klint Andersen; Simon Bjerregaard; Camilla Foged; Jukka Rantanen; Mingshi Yang Journal: Pharm Res Date: 2014-02-19 Impact factor: 4.200
Authors: José Rafael Castrejón-Pita; Alfonso Arturo Castrejón-Pita; Sumeet Suresh Thete; Krishnaraj Sambath; Ian M Hutchings; John Hinch; John R Lister; Osman A Basaran Journal: Proc Natl Acad Sci U S A Date: 2015-03-30 Impact factor: 11.205