摘要 |
Method and apparatus for preparing microparticles using liquid-liquid extraction. A first phase and a second phase are combined to form an emulsion. A portion of the second phase is separated from the emulsion (solvent rich), and the solvent is extracted from the separated second phase, which is then returned (solvent poor) to the emulsion. This process of separation of a solvent rich phase, extraction of solvent, and return of a solvent poor phase, is carried out until a selected level of solvent in the emulsion is achieved. Alternatively, the separated solvent rich phase is not returned to the emulsion, but replaced with another solution, such as an aqueous solution, that is free from solvent. The solvent is preferably extracted into an extraction liquid that functions as a "solvent sink" for the solvent.
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