Characterization of interaction between cephalosporins and charged surfactants using capillary zone electrophoresis.

Capillary electrophoresis offers a new way of characterizing the interaction between surfactants and drugs. This interaction was studied using capillary zone electrophoresis (CZE). It was observed that addition of tetraalkylammonium bromide to the electrolyte buffer at different concentrations of dodecyl trimethylammonium bromide (DTAB) led to a change of the migration time (tm) and of the ionic mobility (mu) of cephalosporins. For quantitative evaluation, a physicochemical model was developed to calculate the aggregation constants (k) and the stoichiometric coefficients (m) between DTAB and cephalosporins. The relative standard deviation of the effective mobilities and of the EOF were estimated.