Determination of benzalkonium chloride in drug formulations by capillary electrophoresis (CE).

A Capillary Electrophoresis method was developed and applied successfully to test the quality of different drug formulations for release and stability studies. In the method an uncoated fused-silica capillary was employed containing a phosphoric acid buffer electrolyte which was brought to pH by triethylamine. The benzalkonium chlorides (BAC-C12 and BAC-C14) present in the standard were completely separated from each other and from the peaks of the main compound. Performance results of the method in terms of system repeatability, precision and accuracy are discussed.