To establish a method for the determination of polymer impurities in ceftazidime raw materials and preparations, a ceftazidime degradation solution containing polymer impurities was prepared by forced polymerization. Polymer impurities in the degradation solution were separated and identified by high performance gel chromatography and the column switching-LC-MSn method. A new RP-HPLC method for ceftazidime polymer was established and validated with a Phenomenex Gemini-C18 column using a mobile phase gradient elution of 0.02 mol·L-1 phosphate buffer, methanol and acetonitrile. The results showed that when using this high performance gel chromatography method some small molecular weight impurities were co-eluted with the polymers, resulting in a poor specificity and poor quantitative accuracy. But when using the RP-HPLC method, four polymer impurities were detected in the 25-45 min time range with good specificity, sensitivity and robustness, including two ceftazidime dimers, trimers, and derivatives. Therefore, the described RP-HPLC method is suitable for the quality control of polymer impurities in ceftazidime, and ceftazidime degradation solution can be used as suitable solution for analysis of ceftazidime polymers.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |