目的 建立HPLC同时测定复方倍他米松注射液中防腐剂苯甲醇、对羟基苯甲酸甲酯、对羟基苯甲酸丙酯含量。方法 以5 mmol·L^-1醋酸铵(含1%三乙胺，用冰醋酸调节pH至5.0)为流动相A，乙腈为流动相B，梯度洗脱，流速1.0 mL·min^-1;检测波长257 nm;柱温30 ℃。结果 苯甲醇、对羟基苯甲酸甲酯及对羟基苯甲酸丙酯3个主峰与相邻色谱峰之间的分离度大于1.5。苯甲醇、对羟基苯甲酸甲酯及对羟基苯甲酸丙酯分别在0.175 9~1.758 6 mg·mL^-1(r=1.000 0)、0.022 3~0.223 1 mg·mL^-1(r=0.999 8)、0.004 35~0.043 47 mg·mL^-1(r=1.000 0)内线性关系良好，平均回收率分别为98.98%，99.38%和100.07%，RSD分别为0.6%，1.3%和1.0%(n=9)。影响因素试验结果表明，对羟基苯甲酸甲酯及对羟基苯甲酸丙酯在高温条件下含量下降。结论 经方法学验证，本方法可用于复方倍他米松注射液中防腐剂的质量控制。

OBJECTIVE To establish an HPLC method for determination of the preservatives in betamethasone injectable suspension, including benzyl alcohol, methylparaben and propylparaben. METHODS The determination method was developed with 5 mmol·L^-1 ammonium acetate(containing 1% triethylamine and adjusted to pH 5.0 with glacial acetic acid) as mobile phase A and acetonitrile as mobile phase B, and gradient elution was performed at a flow rate of 1.0 mL·min^-1. The column temperature was maintained at 30 ℃ and the detection wavelength was set at 257 nm. RESULTS The resolutions between the three main peaks and adjacent peaks were greater than 1.5. The calibration curves of benzyl alcohol, methylparaben and propylparaben showed good linearity in the ranges of 0.175 9-1.758 6 mg·mL^-1(r=1.000 0), 0.022 3-0.223 1 mg·mL^-1(r=0.999 8), 0.004 35-0.043 47 mg·mL^-1(r=1.000 0), respectively. The average recovery rates were 98.98%, 99.38% and 100.07%, and the RSDs were 0.6%,1.3% and 1.0%(n=9), respectively. The results of test of influencing factors showed that the contents of hydroxyphenylmethyl ester and propylparaben decreased at high temperature. CONCLUSION The developed method is proved by validation to be applicable for the quality control of the preservatives in betamethasone injectable suspension.