[Determination of the relative light scattering intensity of aggregates induced by stirring of humanized monoclonal antibody product using dynamic light scattering].

To evaluate the usefulness of dynamic light scattering for estimation of the relative level of aggregates in the manufacturing process of monoclonal antibody substance and its final product, the particle sizes and relative light scattering intensities of monomer and aggregates induced by stirring of humanized monoclonal antibody product were determined by dynamic light scattering. The particle sizes of monomer and aggregates were approximately 5 and 500 nm, respectively. When aggregates and monomer were mixed at the ratio of 1 to 6, the relative light scattering intensity of aggregates was approximately 50%. These findings indicate the relative light scattering intensity of aggregates is approximately 7 times higher than that of monomer. Furthermore, these findings suggest that dynamic light scattering may be useful for the estimation of relative content of aggregates in the case that the relationship between the particle sizes of monomer and aggregates, and their relative light scattering intensities has been already examined.