Current applications in the analysis of pharmaceuticals by capillary electrophoresis. II

Abstract

Part I covered the use of capillary electrophoresis (CE) for main component determinations, stoichiometric assays, analysis of vitamins and regulatory aspects of pharmaceutical analysis. This second article examines the use of CE in the determination of drug-related impurities, chiral separations and the expanding use of capillary electrochromatography (CEC) within the pharmaceutical industry. Impurity determinations are probably the principal role of CE within pharmaceutical analysis and represent a challenge to both the selectivity and sensitivity capabilities of the technique. The main component and structurally-related impurities often have very similar chemical properties which place great requirements on the selectivity necessary. Detection limits of 0.1% area/area are widely accepted as a minimum requirement for a related impurity determination method and this is possible by CE. The use of a number of chiral selective electrolyte additives including proteins, carbohydrates, crown ethers and antibiotics are reviewed. Validation reports of chiral CE methods are discussed in comparison to high performance liquid chromatography methods. This review also examines the increasing use of CEC in the analysis of chiral compounds.