QUANTITATIVE-DETERMINATION OF DRUG COUNTERION STOICHIOMETRY BY CAPILLARY ELECTROPHORESIS

CE has been shown to be a useful technique for the quantitative determination of common drug counterions. Data generated by CE compares well with theoretical ion contents, microanalysis and ion chromatography data. Acceptable method performance in terms of linearity, accuracy, precision of peak areas and migration times for the CE methods are demonstrated. An internal standard was shown to improve injection precision. Given their speed, simplicity and robustness, the CE methods described are now in routine use for batch release of selected drug substance material.