Design Space of Composite Ion Purification Process for IgG4 Antibody Established by Monte Carlo Method

OBJECTIVE To establish design space of the NM 90-Agarose^TM HAM purification process of IgG 4 antibody by Monte Carlo method and verified.

METHODS Using the design of experiment(DOE) all-factor experimental design, the three factors(pH, conductivity, loading capacity) were screened, and the model was established. The design space of the process was determined by Monte Carlo and simulated process robustness in the design space, combining the defined NM90-Agarose^TM HAM purification process with affinity chromatography to purify IgG 4 mAb expressed by Chinese hamster ovary cells(CHO) to verify the robustness of the process parameters.

RESULTS Monte Carlo determined the design space of three key process parameters purified by composite anion chromatography, in which the pH was 4.6±0.1, the conductivity was (50±0.03)ms·cm⁻¹, the loading capacity was ≤60 mg·mL⁻¹; the complex process capability index(CPK) was ≥1.22, and the deviationhe between the predicted value and the actual value was <5%. Monte Carlo had a relatively good prediction performance. The design space could ensure the dynamic stability of the critical quality attributes(CQA) of the process. However, outside the design space, one batch was run, and some of the indicators were unqualified, indicating that this method could meet certain index prediction and played an early warning role in process control. Compared with the traditional superposition method, it was more effective and simple to deal with multiple variables, and improved the reliability of the design space.

CONCLUSION  It is effective, simple and feasible to evaluate the purification process of composite anion chromatography by Monte Carlo model.