Robustness Modelling in Ultrahigh-Pressure Liquid Chromatography Methods
July 16th 2018Many workers in pharmaceutical laboratories are unable to change any aspect of their methods, although they often encounter severe problems and create many out-of-specification (OoS) results. They are particularly afraid to investigate these problems from a chromatographic perspective in case they generate new unforeseen problems. In the literature, however, there are numerous examples showing that it is worthwhile trying to understand the reasons for “unexplainable” behaviour in ultrahigh-pressure liquid chromatography (UHPLC) using modelling. By using modelling, problems can be recognized and often eliminated with legal operations according to the allowed tolerance limits mentioned in pharmacopoeia descriptions. The following article aims to show that “visual chromatographic modelling” can be a useful aid.
Equivalent Column Selection in HPLC
November 7th 2017High 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.
Quality by Design in Pharmaceutical Analysis Using Computer Simulation with UHPLC
May 1st 2014In this study, the quality-by-design principle is applied instead of trial-and-error in the development of a liquid chromatography (LC) method. A mixture of an active pharmaceutical ingredient and its 13 impurities was analyzed on a short narrow-bore column (50 mm ? 2.1 mm, packed with sub-2-?m particles) providing short analysis times. The performance of commercial modelling software for robustness testing was systematically compared to experimental measurements and design-of-experiment–based predictions.
Using MS Data for Peak Tracking in Computer Supported HPLC Method Development
February 1st 2012A 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.