微生物浊度法测定安普霉素及其制剂效价的研究

以金黄色葡萄球菌为试验菌，抗生素检定培养基Ⅲ号为试验用培养基，制成菌悬液。将硫酸安普霉素稀释成不同的浓度加入菌悬液中，37 ℃培养3～4 h，确立浓度的对数值与相对应的吸光度呈直线相关的线性范围，并对所建立的浊度法进行准确度、精密度、专属性及适用性等验证。结果表明，安普霉素的浓度在2.9～7.2 U/mL之间，其浓度的对数值与相对应的吸光度呈直线相关，相关系数r＝0.9988。经t检验，安普霉素浓度的对数值与相对应的吸光度回归效果显著。所建立的浊度法平均回收率为99.82%，平均可信限率为2.48%，相对标准偏差（RSD）为1.86%。管碟法与比浊法所测结果无显著差异。因此，本方法具有可信限率低、灵敏度高、精密度高、快速等优点，可用于硫酸安普霉素及其制剂的效价测定。

The Research of Turbidimetric Method Determinating the Potency of Apramycin

Apramycin was diluted to different concentrations and was added to bacterium suspension which is made of Staphylococcus aureus and antibiotics standardization medium Ⅲ. After cultivated for 3 to 4 h at 37 ℃, the linearity of the dose-response relationship was analysised. The accuracy of developing turbidimetric method was checked. At the concentration range from 2.9 to 7.2 U/mL, log values of concentrations of apramycin were linear correlation with corresponding opacities, which correlation coefficient was r=0.9988. By the t-test, regression effect of log values of concentrations of apramycin with corresponding opacities was significant. Average recovery is 99.82%, and average confidence rate is 2.48%, and relative standard deviation is 1.86%. Potencies were unitied which determined by turbidimetric method and cylinder-plate method. Turbidimetric method has low confidence rate, high sensitivity, high precision,so that can be used to determine apramycin and apramycin peprations.