ABSTRACT
Chromatographic methods permit the scientist to separate closely related components of complex mixtures. Chromatographic methods can either be qualitative, in the sense they are used to identify active drug substances, to establish the amount of a given active substance. The quantitative chromatographic methods are also divided into subtypes depending on the purpose, namely, assay, impurities and related substances, residual solvents, and dissolution testing. Analytical methods for the given tests will require a slightly different validation approach. The robustness of an analytical procedure is a measure of its capacity to remain unaffected by small but deliberate variations in method parameters and provides an indication of its reliability during normal usage. Robustness testing results enable conclusions to be made on the influence of factors evaluated on the response functions and hence facilitate, if necessary, inclusion of precautionary statements in the method's procedure. A statistical technique based on Plackett–Burman experimental design can be used to detect factors that estimate the factor influence.
