色甘酸钠滴眼液中对羟基苯甲酸乙酯最低有效抑菌浓度考察

Study on the minimum effective bacteriostasis concentration of ethyl p-hydroxybenzoate in sodium cromoglicate eye drops

目的：考察色甘酸钠滴眼液中抑菌剂对羟基苯甲酸乙酯（尼泊金乙酯）浓度的合理性。方法：采用Agilent HC-C18色谱柱（250 mm×4.6 mm,5μm）,以0.005 mol·L-1醋酸铵溶液（每1000 mL中含三乙胺10 mL,用冰醋酸调pH5.0±0.5）-乙腈（50∶50）为流动相,流速1.0 mL·min-1,检测波长256 nm,对色甘酸钠滴眼液中抑菌剂对羟基苯甲酸乙酯浓度的测定;选择有代表性的微生物金黄色葡萄球菌、铜绿假单胞菌、大肠埃希菌、白色念珠菌、黑曲霉,在色甘酸钠滴眼液样品中加入含不同量对羟基苯甲酸乙酯后进行抑菌效力测定。结果：采用RP-HPLC法对羟基苯甲酸乙酯浓度在0.31~310μg·mL-1范围内线性关系良好（r=0.9999）,平均回收率（n=6）为99.3%,RSD=0.75%;样品中对羟基苯甲酸乙酯浓度为0.024%不能符合中国药典中抑菌效力判断标准,而浓度为0.06%对上述的5种菌有良好的抑制作用,为最低有效剂量。结论：RP-HPLC法能准确地测定色甘酸钠滴眼液中对羟基苯甲酸乙酯,浓度0.06%为其滴眼液中最低有效抑菌浓度。

Objective： To study the rationality of bacteriostasis concentration of ethyl p- hydroxybenzoate（ ethylparaben） in sodium cromoglicate eye drops. Methods： Agilent HC- C18column（ 250 mm × 4. 6 mm,5 μm）was adopted; the mobile phase was 0. 005 mol·L- 1ammonium acetate solution（ 10 mL three amine containing each of the 1000 mL,pH 5. 0 ± 0. 5 glacial acetic acid）- acetonitrile（ 50∶ 50） at the flow rate of 1 mL·min- 1,and the detection wavelength was 256 nm. The concentration of ethyl p- hydroxybenzoate in sodium cromoglicate eye drops was determined. Choose the representative 5 kinds of bacteria including Staphylococcus aureus,Pseudomonas aeruginosa,Escherichia coli,Candida albicans,Aspergillus niger; the bacteriostasis potency of samples was determined after adding ethyl p- hydroxybenzoate of different amounts. Results： Using the method of RP-HPLC,there was good linearity in ethyl p- hydroxybenzoate concentration range of 0. 31- 310 μg·mL- 1（ r= 0. 9999）; the average recovery（ n = 6） was 99. 3% with RSD of 0. 75%; ethyl p- hydroxybenzoate concentration with 0. 024% in the sample did not meet bacteriostasis effectiveness criteria of Chinese Pharmacopoeia,while there was a good bacteriostasis effect when the concentration of the 5 kinds of bacteria above was0. 06% which was the lowest effective dose. Conclusion： The RP- HPLC method can accurately determine ethyl p- hydroxybenzoate in sodium cromoglicate eye drops,and the concentration of 0. 06% for the eye drops is minimum effective bacteriostasis concentration.