Precision study on capillary electrophoresis methods for metacycline

Comparative study of robustness between micellar electrokinetic capillary chromatography and high-performance liquid chromatography using one-variable-at-a-time and a new multi-variable-at-a-time approach

Micellar electrokinetic capillary chromatography and reverse-phase liquid chromatography methods were developed in order to perform robustness testing to determine the caffeine content in beverages. Both methods were fully validated and two different robustness approaches were applied. One-variable-at-a-time (OVAT) approach at eleven levels (0; +/-1; +/-2; +/-3; +/-4; +/-5 units) was carried out and compared with multi-variable-at-a-time (MVAT) approach at three levels (+/-1 unit per investigated parameter). Four analysts in two laboratories on two capillary electrophoresis and two RPLC equipments have tested the samples. Robustness was statistically analyzed using peak area, migration or retention time, symmetry, and resolution of caffeine and sulfacetamide as internal standard, and presented as R.S.D. values. The RPLC method was found to be more sensitive than the MEKC method. Both methods showed acceptable robustness level for OVAT approach, whilst MEKC method was more robust when the determination of real samples coming from different beverages was based on the MVAT approach.

Precision of micellar electrokinetic capillary chromatography in the determination of seven antibiotics in pharmaceuticals and feedstuffs

Validation of analytical procedures is important for their efficient and reliable application. The International Conference on Harmonisation (ICH), Food and Drug Administration (FDA) and pharmacopoeia guidelines achieved a great deal in harmonising the definitions of the required validation characteristics. It is well known that poor reproducibility limits the practical implementation of capillary electrophoresis (CE). A precision study on four different MEKC methods was performed with 11 samples, containing seven antibiotics, by two analysts, in few days, on two capillary electrophoresis instruments. Five pharmaceutical preparations and three animal feeds were used. Precision was statistically analysed using migration time, peak area and height of each compound, as well as electroosmotic front (EOF). In 25 of 31 cases, the reproducibility of peak area, peak height and migration time was good (<5%). In most cases the reproducibility of peak area was much better than the reproducibility of peak height. The worst reproducibility that we observed was 12.7% for peak height and 7.6% for peak area.

Ruggedness and robustness testing

Due to the strict regulatory requirements, especially in pharmaceutical analysis, analysis results with an acceptable quality should be reported. Thus, a proper validation of the measurement method is required. In this context, ruggedness and robustness testing becomes increasingly more important. In this review, the definitions of ruggedness and robustness are given, followed by a short explanation of the different approaches applied to examine the ruggedness or the robustness of an analytical method. Then, case studies, describing ruggedness or robustness tests of high-performance liquid chromatographic (HPLC), capillary electrophoretic (CE), gas chromatographic (GC), supercritical fluid chromatographic (SFC), and ultra-performance liquid chromatographic (UPLC) assay methods, are critically reviewed and discussed. Mainly publications of the last 10 years are considered.