Screening Acid-Base Constants by Capillary Electrophoresis
The acid-base constants of the most frequently used antianginals (diltiazem, nadolol, propranolol and verapamil) were determined using capillary zone electrophoresis (CZE). This method is based on measuring the electrophoretic mobility of the solute as a function of pH. The buffer employed was composed of borate-phosphate buffered across the pH range of 3.0–11.2. The acid-base constants were determined by performing linear and non-linear regression on the data obtained. The results were compared with those reported in literature and with those obtained by a spectrophotometric method. After comparison of the values, no significant differences were observed between the three acid-base constants.