高效液相色谱法测定自制苯海拉明乳膏中羟苯乙酯的含量

Determination of ethyl hydroxybenzoate in diphenhydramine cream by HPLC

目的 建立测定医院自制制剂苯海拉明乳膏中羟苯乙酯的含量测定方法。方法 采用高效液相色谱法（HPLC）。色谱柱：AgilentEclipsePlusC18（4.6mm×250mm,5μm）色谱柱;流动相：甲醇-0.03mol·L^-1磷酸二氢钾溶液（含0.1%三乙胺,用50%磷酸调pH3.0±0.03）=60∶40;检测波长：258nm;柱温：25℃;流速：0.9mL·min^-1;进样体积：20μL。结果 羟苯乙酯测定质量浓度在0.02-0.10g·L^-1范围内与其相应峰面积积分值呈良好线性关系（r=0.9995）;精密度、稳定性、重复性试验相对标准偏差（RSD）分别为1.6%、1.9%、2.0%;平均绝对回收率为92.7%,RSD为4.3%（n=9）;平均相对回收率为102.5%,RSD为3.6%（n=9）。结论 该方法专属性、重复性、准确性较好,可用于苯海拉明乳膏中羟苯乙酯的含量测定。

Objective To establish a method of quantitative determination of ethyl hydroxybenzoate in diphenhydramine cream.Meth-ods The HPLC method was adopted with the Agilent Eclipse Plus-C18 column（4.6 mm ×250 mm,5 μm）at room temperature（25℃）and methanol-0.03 mol·L^-1 phosphoric acid solution（pH adjusted to 3.0 ±0.03）（60∶40）as the mobile phase at the flow rate of 0.9 mL·min^-1 .The detection wavelength for ethyl hydroxybenzoate was 258 nm,and the injection volume was 20 μL.Results The good linear relationship for ethyl hydroxybenzoate was in the range of 0.02 ~0.10 g·L^-1 （r =0.999 5）.RSDs of ethyl hydroxybenzo-ate for precision,stability and reproducibility tests were 1.6 %,1.9% and 2.0 %,respectively.The average absolute recovery of ethyl hydroxybenzoate was 92.7%（RSD =4.3 %,n =9）,while the average relative recovery was 102.5 %（RSD =3.6 %,n =9）.Con-clusions This established method was specific,accurate and reproducible for the quantitative determination of ethyl hydroxybenzoate in diphenhydramine cream.