Using Analytical Quality by Design to improve analytical method development in vaccines quality control: Application...

Analytical quality by design (AQbD) is an enhanced approach for the development of analytical methods. AQbD has received much industrial interest, being the subject of several recently published draft guidelines. This article demonstrates the application of AQbD to determine the quantity of non-adsorbed polysaccharide polyribosyl ribitol phosphate (PRP) and percentage of depolymerized PRP in a commercial hexavalent liquid vaccine, and establishment of an analytical control strategy (ACS). The quantification method developed is high-performance anion-exchange chromatography (HPAEC) with pulsed amperometric detection, preceded by ultracentrifugation (sample preparation) for separation of the depolymerized polysaccharide from the native adsorbed polysaccharide. The first step was to develop the analytical target profile (ATP) which defines the purpose of the analytical measurement as well as the development scope. As a second step, risk assessment tools were used for identification and ranking of the critical method variables (CMVs) which have a potential impact on method performance if not controlled. Based on a multivariate Design of Experiments (DoE) approach, a proposed method operational design region (MODR) was determined for seven CMVs. Finally, the ACS was established from the understanding of the analytical method and the robustness study. This article focuses on robust and operational ranges of critical parameters linked to the ultracentrifugation and chromatographic steps for depolymerized polysaccharide content control. The design space proposed for CMVs corresponds to the ranges that ensure a product that complies with the previously established precision criteria (±2% equivalent to ± 10 % around the product criterion, which is 20 % for depolymerized polysaccharide control limit). The following design space was established from the DoE statistical modeling for ultracentrifugation critical parameters: [483,000-520,000] g for speed, [11-19]°C for temperature, [29-34] minutes for duration, and from extemporaneous to 8 min for holding time before supernatant recuperation after the ultracentrifugation. For chromatographic critical parameters, the MODR is [2-6] psi for mobile phase helium pressure, [0-7] days for mobile phase storage time, and [0-3] days for samples storage time in the autosampler at 5 °C. Methods optimized using the AQbD approach provide strong justifications during regulatory filing for the selection of analytical CMVs, and for the ACS to be applied during the lifecycle management of the method.