A comparative study of antisolvent versus salting-out precipitations of glycopeptide vancomycin: Precipitation efficiency and product qualities

Precipitation has been studied as an alternative downstream processing step of biopharmaceuticals to replace chromatography. In protein precipitation, previous studies showed precipitation efficiency and product qualities were influenced by the precipitation agents (e.g., salts, organic solvents, polymers). For bioactive peptides, however, the impacts of precipitation agents had rarely been studied. We previously studied salting-out precipitation of glycopeptide vancomycin (Van) used as the model peptide. The present work compared antisolvent (with acetone) and salting-out precipitations in their precipitation efficiency and product qualities. The phase behavior study showed that heavy precipitates composed of nanoparticles were the predominant products of antisolvent precipitation, in contrast to crystalline microparticles produced by salting-out. At their respective optimal conditions (e.g., pH, Van concentration), batch antisolvent precipitation had significantly higher yield than salting-out. Other than faster dissolution of antisolvent precipitates attributed to their smaller size, both precipitates exhibited comparable purity, peptide secondary structures, thermal stability, and antimicrobial activity.