Applications of Capillary Electrophoresis to Pharmaceutical and Biochemical Analysis

Abstract

In the last decades, miniaturized separation techniques have rapidly gained popularity in different areas of analysis such as pharmaceutical, biopharmaceutical, clinical, biological, environmental, and forensics. The great advantages presented by the analytical miniaturized techniques, including high separation efficiency and resolution, rapid analysis and minimal consumption of reagents and samples, make them an attractive alternative to the conventional chromatographic methods.In this sense, capillary electrophoresis (CE) is a family of related techniques that employs narrow-bore capillaries to perform highly efficient separations from large to small molecules. Different modes are applied in CE. Capillary zone electrophoresis (CZE) using a simple buffer as electrolyte, is widely used for the analysis of inorganic and organic ions. Another CE mode is electrokinetic chromatography (EKC),in which the separation principle is based on the differential partition between the analytes and a pseudostationary phase as well as the migration behavior of the analytes. Several nanostructures are used as pseudostationary phases like micelles, microemulsion droplets, and polymers, increasing the selectivity and versatility of the analytical system.CE advantages with respect to other analytical techniques comprise very high resolution in short time of analysis, versatility, the possibility to analyze molecules without chromophore groups, simultaneous analysis of compounds with different hydrophobic characteristics, small sample volume, and low cost. Moreover, it is possible to adapt this technique to the analysis of numerous types of compounds like biological macromolecules, chiral compounds, inorganic ions, organic acids, DNA fragments and even whole cells and virus particles. An increasing number of CE applications are in progress in many clinical laboratories. As this technique employs small sample volumes, is ideal for the analysis of biological fluids in which the limited amount of sample represents a challenge. In pharmaceutical quality control, it is possible to determine active ingredients in the presence of related substances with different physicochemical characteristics, especially chiral impurities in the final products using the same analytical system with a relatively simple instrumental. Moreover, numerous applications are reported in the analysis of inorganic ions. Also, the determination of macromolecules such as polysaccharides, therapeutic proteins, and flavonoids present in plant extracts, biological and biopharmaceutical products may also be analyzed with this technique.In summary, CE has become an important analytical tool in the field of research, clinics and pharmaceutical industry offering a large number of applications, in biological, natural and pharmaceutical samples, as an alternative or complementary option to traditional analytical techniques to implement in the routine laboratory.