Subvisible Particle Analysis of 17 Monoclonal Antibodies Approved in China Using Flow Imaging and Light Obscuration

In the study, subvisible particles in 205 samples from 17 commercial mAb drug products approved in China were analyzed using light obscuration (LO) and flow imaging microscopy (FIM) methods. For each method, a total 633 tests (runs) were performed. In the tests, samples in state of lyophilized powder or syringe package had significantly higher particle concentrations. It was confirmed by analyzing the 205 drug product samples that FIM particle counts are generally higher than LO counts. The cause of the higher counts of FIM method than LO counts was examined by looking into the contribution of proteinaceous, translucent particles in the samples. The data of the study showed that the number of proteinaceous, translucent particles was a factor in the elevated counts of FIM method compared to LO method.