HPLC法测定三种制剂中水杨酸的含量

目的：建立测定三种制剂（水杨酸软膏、水杨酸硫软膏、复方硫软膏）中水杨酸含量的方法。方法：采用HPLC法,色谱柱：Diamonsil C18（250 mm×4.6 mm,5μm）;流动相：甲醇-0.1 mol·L^-1磷酸二氢钠（30：70）;检测波长：231 nm;流速：1.0 mL·min^-1;柱温：35℃;进样量：10μL。结果：水杨酸与其它杂质峰分离良好,水杨酸在12.32-123.20μg·mL^-1范围内与峰面积呈良好的线性关系（r=1.000 0）;水杨酸在水杨酸软膏、水杨酸硫软膏、复方硫软膏的平均回收率分别为100.55%、99.96%、99.13%,RSD分别为0.95%（n=9）、0.96%（n=9）、1.15%（n=9）。结论：采用该方法测定三种制剂中的水杨酸含量,简便易行,结果准确,可作为三种制剂中水杨酸的质量控制方法。

Content determination of salicylic acid in three preparations by HPLC

Objective： To establish the HPLC method for determining the content of salicylic acid in three preparations（salicylic acid ointment, salicylic acid and sulfur ointment, compound sulfur sublimate ointment）. Methods： HPLC analysis was carried out with Diamonsil C18 column（250 mm × 4.6 mm, 5 μm）, the mobile phase consisted of methanol- 0.1 mol·L^-1 sodium dihydrophosphate solution（30 ： 70）, the detection wavelength was set at 231 nm, the flow rate was 1.0 mL·min^-1, the column temperature was 35 ℃ and the sample size was 10 μL. Results： The sample was separated well from impurities by this HPLC method. The calibration curve of salicylic acid was linear in the range of 12.32 – 123.20 μg·mL^-1（r = 1.000 0）. The average recoveries and the RSD of salicylic acid were 100.55% and 0.95%（n = 9） in the salicylic acid ointment, 99.96% and 0.96%（n = 9） in the salicylic acid and sulfur ointment, 99.13% and 1.15%（n = 9） in sulfur sublimate ointment, respectively. Conclusion： This method is accurate and feasible, which can be applied as the quantitative method for the determination of salicylic acid in three preparations.