Electrophoretic behaviour of pharmacologically active alkylxanthines

Area of Science:

• Analytical Chemistry
• Separation Science
• Pharmaceutical Analysis

Background:

• Alkylxanthines are common in pharmaceutical preparations.
• Efficient separation of these compounds is crucial for quality control.
• Existing separation methods may require optimization for complex mixtures.

Purpose of the Study:

• To evaluate various electrophoretic techniques for separating ionizable and neutral alkylxanthines.
• To compare the performance of capillary zone electrophoresis (CZE), cyclodextrin electrokinetic chromatography, and micellar electrokinetic chromatography (MEKC).
• To identify the most effective surfactant and separation conditions for resolving similar xanthine structures.

Main Methods:

• Capillary Zone Electrophoresis (CZE) in an alkaline medium.
• Cyclodextrin electrokinetic chromatography with carboxymethyl-beta-cyclodextrin.
• Micellar Electrokinetic Chromatography (MEKC) using sodium dodecyl sulfate (SDS) and bile salts (including taurodeoxycholic acid).

Main Results:

• CZE effectively separated ionizable xanthines and dyphylline.
• Cyclodextrin electrokinetic chromatography offered only partial resolution of neutral xanthines.
• MEKC with bile salts demonstrated superior separation capability compared to SDS.
• Taurodeoxycholic acid achieved baseline separation of various xanthines.

Conclusions:

• MEKC using bile salts, especially taurodeoxycholic acid, is a highly effective method for separating pharmaceutical alkylxanthines.
• Electrophoretic techniques provide valuable tools for the analysis and quality control of xanthine-containing drugs.
• Method optimization is key to achieving high-resolution separations of structurally similar compounds.