Clearance Of Aggregates And Fragments In Monoclonal Antibodies And Optimization Of Purity Detection

The fusion protein is a novel recombinant protein produced by the fusion technology of the Fc fragments of immunoglobulin with certain protein domains which possess specific binding functions leading to tumor killing.Since they have both a long half-life and targeting well,the fusion protein drugs have been widely used in tumors and autoimmune treatment.The fusion protein X involved in this article contains several low-molecule substances whose isoelectric point and molecular weight are so close to the target protein that it is hard to remove them by current platform technology.In this study,resin type,dynamic binding capacity,buffer system,sample volume,flow rate,linear elution column volume for different commercial resins were thoroughly compared.In particular,the elution peak collection conditions were investigated and determined.Then,the process was further optimized and integrated to scale up process for pilot production by optimizing the experimental design.The final process is: The sample is loaded at pH 5.2 and conductance 4 mS/cm.The loading mass is 15 mg/ml resin and the flow rate is 180 cm/h.Sample is gradient eluted with sodium chloride for 20 column volumes.Sample collection is based on the absorbance of UV280.Collection of the eluent is started when the UV280 reached 1.5 Au and stopped when it falls to 2 Au.After optimization of the process,the rCE-SDS and NrCE-SDS showed the monomer content increased to 97.6% and 97.3% respectively.In the pilot production,the monomer content analyzed by rCE-SDS and NrCE-SDS were all above 95.6% and the highest was 97.1% after cation exchange chromatography.The purity analyzed by SEC-HPLC was above 95%.Residual Protein A were all below 4 ng/mg,endotoxin content was less than 0.02 EU/mg,all product quality indicators were in line with product quality standards.