Determination of Related Substances in Ticarcillin Disodium and Potassium Clavulanate for Injection by HPLC with Gradient Elution

OBJECTIVE To establish a gradient HPLC method for related substances of ticarcillin disodium-clavulanate potassium for injection. METHODS The column was Waters XBridge^TM C₁₈(4.6 mm×250 mm, 5 μm). Mobile phase A was 0.01 mol·L^-1 ammonium dibasic phosphate solution (pH 7.0), mobile phase B was 0.01 mol·L^-1 ammonium dibasic phosphate solution (pH 7.0)-menthol(50:50). The flow rate was 1.0 mL·min^-1, linear gradient elution. The column temperature was 30℃. The detection wavelength was 220 nm. RESULTS Contrast to isocratic elution, gradient elution was more widely applied on the separation of the related substance. The resolution and sensitivity of related substance was in accord with the demands. The impurities and impurity A were all separated from ticarcillin and clavulanate. Limit of detection for ticarcillin was 4.8 ng. Limit of detection for Clavulanate was 7.3 ng. The content of ticarcillin impurity A was less than 1.5%, the content of the single biggest impurity was less than 2.0%, the total content of related substance were less than 4.0% in samples of the materiel and preparation. CONCLUSION The proposed HPLC method was specific, sensitive and suitable for the determination of related substances of ticarcillin and ticarcillin disodium-clavulanate potassium for injection.