Process for the preparation of amorphous cilastatin sodium

摘要

A process for the preparation of pure cilastatin sodium in an amorphous form is described. This involves recovering cilastatin sodium from a solution which contains an organic solvent, or homogeneous mixture of organic solvents and water, by solvent precipitation. The addition of an anti-solvent, where cilastatin sodium is insoluble and is miscible with the solvent in which the cilastatin is dissolved, is described to be added to the solution of cilastatin sodium. The volume of anti-solvent is disclosed to range from about 5 to 100 times the weight input of cilastatin. Cilastatin sodium is to be dissolved in a solvent present at a concentration of about 20% to 80% weight per volume.