Hans-Jürgen Rieger

Presenting a novel chromatographic modelling method to establish QbD-compliant comparative testing of eluent design spaces.

With the era of new complex drug products there is an increasing demand on multivariate modelling tools to integrate robust analytical method design, facilitate efficient and science-based change management, and improve communication between regulators and industry. Mechanistic models provide several advantages in terms of modelling efficiency, versatility, and high predictive power. The following case study will demonstrate a robust method design for industrial Cannabis sativa.

Food analysis is often handled less thoroughly than pharmaceutical analysis because of the smaller life-threatening risk expected from foodstuffs. However, food analysis is still a major focus for chromatographers from a scientific and an analytical point of view. Adoption of modern “in‑silico” techniques, such as chromatographic modelling, offer analysts new possibilities for method development.

High performance liquid chromatography (HPLC) methods are used today to control the quality of many chemical and pharmaceutical products. The methods are usually developed by optimizing the properties of the mobile phase with a specific column. However, if the original column is no longer in production, the result will often change when a different column is used. In this case, we were interested in finding one or two equivalent columns that can replace the original column without changes in selectivity and robustness. This study demonstrates a new way to compare columns and select suitable replacement columns. The presented method will also allow the evaluation of different columns with the same method, as well as the evaluation of the robustness of the common method with different columns.

A new type of method development that uses modeling to find the "best" separation for high performance liquid chromatography (HPLC) was investigated and principles of Quality by Design (QbD) were followed when planning the investigation. The process delivered precise results and the method was able be transferred to a routine quality control (QC) laboratory.

A systematic way to develop HPLC methods consists of building up and running a useful set of experiments (DOE, design of experiments) to evaluate the influence of several factors or method conditions on the selectivity of a chromatogram. The crucial part here is the peak tracking between the chromatograms.