盐酸甲氧氯普胺注射液中抗氧剂亚硫酸氢钠的含量测定

Determination of antioxidant sodium bisulfite in metoclopramide dihydrochloride injection

目的：建立盐酸甲氧氯普胺注射液中抗氧剂亚硫酸氢钠的含量测定方法。方法：基于在SO2存在下能使酸性品红溶液褪色的原理，采用比色法在549 nm波长处测定吸光度,用标准曲线法测定含量。结果：无水亚硫酸钠在9.917～29.75mg/ml，吸光度的倒数与其浓度（以SO2计）呈良好的线性关系，r =0.999，平均回收率为99.3%。结论：该方法操作简单，结果准确可靠，可作为制剂中抗氧剂亚硫酸氢钠的含量测定。

Objective： To develop a method for the determination of sodium bisulfite in metoclopramide dihydrochloride injection.Methods： Based on the fading of fuchsin acid solution in the present of SO2, a colorimetric method was established to be used for the determination of absorbance at the wavelength of 549 nm. The amount of sodium bisulifte in sample was calculated by reference to a calibration curve obtained.Results： The reciprocal of absorbance and the concentrations of anhydrous sodium sulifte （calculated based on sulfur dioxide） showed a good linear relationship over the range of 9.917~29.75mg/ml （r=0.999） with an average recovery of 99.3%.Conclusion： This method is simple and accurate and can be used for the determination of sodium bisulifte in metoclopramide dihydrochloride injection.