Paesen J, Roets E, Hoogmartens J
Laboratorium voor Farmaceutische Chemie en Analyse van Geneesmiddelen, Faculteit Farmaceutische Wetenschappen, Katholieke Universiteit Leuven, Belgium.
J Pharm Biomed Anal. 1998 May;17(1):53-6. doi: 10.1016/s0731-7085(97)00158-1.
The stability of the macrolide antibiotic erythromycin, incorporated at a 2% m/m concentration in a hydrophilic creme basis containing 2% m/m of chlorocresol, was monitored over a period of 2 months using liquid chromatography as the analytical method. Extracts of the creme were analysed using wide-pore poly(styrene-divinylbenzene) PLRP-S 1000 A as the stationary phase and a mixture of 2-methyl-2-propanol-acetonitrile-potassium phosphate buffer (pH 11.0; 0.02 M)-water (165:30:50:755, v/v/v/v) as the mobile phase. The method showed good selectivity towards chlorocresol, erythromycin A, its related substances and degradation products. As the pH of the creme containing erythromycin was 8.6, alkaline degradation products were expected to be formed. The presence of pseudoerythromycin A enol ether was observed after storage of the creme for 1 week at a temperature of 25 degrees C. After 1 month the content of erythromycin was still more than 95%.
将浓度为2%（m/m）的大环内酯类抗生素红霉素加入到含有2%（m/m）氯甲酚的亲水性乳膏基质中，以液相色谱作为分析方法，在2个月的时间内监测其稳定性。乳膏提取物的分析采用孔径较大的聚（苯乙烯-二乙烯基苯）PLRP-S 1000 A作为固定相，以2-甲基-2-丙醇-乙腈-磷酸钾缓冲液（pH 11.0；0.02 M）-水（165:30:50:755，v/v/v/v）的混合物作为流动相。该方法对氯甲酚、红霉素A、其相关物质和降解产物具有良好的选择性。由于含红霉素的乳膏pH值为8.6，预计会形成碱性降解产物。在25℃温度下将乳膏储存1周后，观察到假红霉素A烯醇醚的存在。1个月后，红霉素含量仍超过95%。
