Simultaneous determination of 4 bacteriostatic agents in triamcinolon acetonide econazole cream by HPLC under gradient elution
Objective:To develop an HPLC method with gradient elution for the simultaneous determination of 4 bacteriostatic agents in triamcinolone acetonide econazole cream from the different manufacturers.Methods:The test was performed on a Waters Symmetry C18 column(250 mm ×4.6 mm,5 μm)under gradient elution of metha-nol(A)and methanol-0.02 mol·L-1 sodium dihydrogen phosphate solution(B).The flow rate of 1.0 mL·min-1 and the column temperature was 35 ℃.The detection wavelengths were 228 nm and 254 nm.Results:The good separation of the bacteriostatic agents peaks were achieved.The linear ranges of benzoic acid,methyl hydroxybenzoate,ethylparaben and propylparaben fell into 0.010 348-0.155 22 mg·mL-1,0.009 876-0.148145 mg·mL-1,0.010 106-0.151 588 mg·mL-1 and 0.010 259-0.153 882 mg·mL-1 respectively.The av-erage recoveries were 99.68%(RSD=2.35%),100.21%(RSD=1.78%),100.47%(RSD=1.59%)and 100.06%(RSD=1.65%)respectively.The LODs were 3 × 10-5 mg·mL-1,1.67 × 10-5 mg·mL-1,1.67 × 10-5 mg·mL-1 and 1.67 × 10-5 mg·mL-1 respectively.Conclusion:The established method is sensitive and accurate,and has the good separation.It provides the reliable basis for the quality control of triamcinolone ace-tonide econazole cream.