HPLC

Analytical chemistry students need hands-on exposure to different chromatographic methods and approaches to adequately prepare them for their professional careers. This can be difficult to achieve; an experimental approach is often unfeasible and protracted, especially when run times can be 15 minutes or more and available instrument time can be limited. Equally, lectures displaying static specimen chromatograms and their evolution under varying conditions often do not adequately provide a sense of the processes occurring. A set of virtual chromatography exercises have been developed with the goal of achieving increased teaching effectiveness through the use of ACD/Labs’ software. The modelling tools are well suited to illustrating and visualising the effects of changing various parameters, and the exercises described explore the optimization of temperature and gradient elution for GC and HPLC respectively.

Method development investigation approaches vary widely from organization to organization. Even problems that appear entirely equivalent may be solved in very different ways. However, certain commonalities have begun to emerge in most organizations. For example, column screening and gradient optimization, viewed broadly, are common approaches, even if the specifics of how they are applied may be different from group to group. An increasingly common approach to modern method development is the injection of multiple vials under each set of conditions. Each vial (or subsample) contains a subset of the overall project compounds. When the contents of each subsample are viewed as a whole, the composite represents the range of project compounds that must be considered in the design of a method. It is common to inject separate subsamples for blanks/excipients, pure standards, and for multiple stress conditions associated with stability-indicating methods.

This approach to composite sample method development illustrates the link between decision-making systems, automation, and data reduction. There are a number of advantages to the composite sample approach, but additional challenges are presented in terms of data reduction and visualization. This presentation will use several example systems to illustrate new tools that have been developed to efficiently apply the composite sample concept.

Analytical chemistry is the latest pharmaceutical sciences discipline to embrace Quality by Design (QbD). ICH Q8-10 were originally applied to manufacturing processes (active pharmaceutical ingredients and formulated drug products), however the concepts and approaches are now being expanded on to apply to analytical method development. One result of applying Analytical QbD (AQbD) to analytical methods development is increased method knowledge. This increased knowledge occurs via systematic method development, risk assessments, and design of experiments, all of which contribute to a method 'design space' within which the method meets pre-set method performance criteria (the Analytical Target Profile). However, despite the benefits of achieving predictable method performance and robustness, the number of experiments required to explore the analytical design space (and more importantly, the amount of data that has to be manually converted into knowledge) limits the practicality of the approach as compared to more traditional fit for purpose approaches.

We present here a computer assisted approach to automate the AQbD LC method development workflow, thereby significantly reducing (human) resources. The computer assisted approach is built upon ACD/AutoChrom software. We developed an automated data processing (ADP) application to integrate the DOE execution, chromatographic peak integration, component tracking, and retention simulation. Combined with orthogonal method scouting, fast UHPLC separation, waved selection and optimization of stationary phase, pH, solvent, temperature, and gradient, the automated workflow enables a much faster turnaround of QbD method development and makes it practical for routine project support at all stages of development.