Survey and Establishment of Points to Consider for Application of Analytical Techniques to Evaluate Protein Aggregates and Insoluble Particles in Biopharmaceuticals: Experiences in Japan Biopharmaceutical Consortium.

Protein aggregates and insoluble particles in biopharmaceutical products are impurities that can elicit immunogenicity. The protein aggregates and insoluble particles form during manufacturing and storage, and should be characterized to optimize the manufacturing process and establish a control strategy. Several issues regarding the evaluation and control of these particles have been concerned, and collaborative studies have been conducted in the Japan Biopharmaceutical Consortium to address them. However, there is still no consensus for utilizing analytical techniques in parallel to establish a control strategy for such protein aggregates and insoluble particles, which range in size from a few nanometers to several hundred micrometers. Therefore, in this study, we surveyed Japanese biopharmaceutical companies through a questionnaire including questions regarding analytical techniques used to establish control strategies for protein aggregates and insoluble particles at various development phases. To summary the survey results, we found that size exclusion chromatography, light obscuration, and visual inspection are consistently used from early development and formulation optimization stage to commercial manufacturing. Apart from the light obscuration method, flow imaging (FI) was the most commonly used technique for subvisible particle characterization; thus, the use of FI to establish a control strategy was documented. The recommendation for establishing a control strategy for protein aggregates and insoluble particles based on life-cycle of drug development are summarized.