Process for the isolation of a pharmaceutically acceptable alkali metal salt of clavulanic acid

摘要

The invention relates to the process for the isolation of a pharmaceutically acceptable alkali metal salt of clavulanic acid from a fermentation broth containing impure clavulanic acid comprising the steps of filtration of the fermented broth, extraction of the clavulanic acid to a water immiscible or partly water immiscible solvent at pH from 1.2 - 2, precipitation of an alkali metal salt A of clavulanic acid by addition of a solution of an alkali metal alkylalkanoate, characterized by the following steps: before the filtration the fermented broth containing clavulanic acid is diluted with water, a flocculating agent is added and the pH is adjusted to 3 - 5 for further purification the alkali metal salt A of clavulanic acid is converted to clavulanic acid by addition of an inorganic acid and is extracted into a water immiscible or partly water immiscible solvent a solution of a different alkali metal B alkyl alkanoate is added and the alkali metal salt B of clavulanic acid is precipitated.