Department of Antibiotics, Anhui Institute for Food and Drug Control, Hefei 230051, China.
AAPS PharmSciTech. 2013 Jun;14(2):578-84. doi: 10.1208/s12249-013-9942-4. Epub 2013 Mar 6.
Photodegradation kinetics of fleroxacin were investigated in different injections. Five commercial formulations were analyzed before and after irradiation by determining residual volumes of fleroxacin with high-pressure liquid chromatography (HPLC), and different decomposition functions and models were obtained. Concentration levels of fleroxacin in injections caused the differences in photodegradation kinetics instead of ingredients. Influences of different pH values and presence of NaCl on photodegradation of fleroxacin were observed. Low pH value decreased the efficacy of photolysis and enhanced photostability of fleroxacin injections. Tentative structure of a new degradation product afforded was proposed. An acute toxicity assay using the bioluminescent bacterium Q67 was performed for fleroxacin injections after exposure to light. The research proved that fleroxacin was more photolabile in dilute injection, and acute toxicity of dilute injection increased more rapidly than that of concentrated injection during irradiation.
氟罗沙星在不同注射液中的光降解动力学进行了研究。通过高效液相色谱法（HPLC）测定氟罗沙星的残留体积，对五种市售制剂进行了辐照前后的分析，得到了不同的分解函数和模型。注射液中氟罗沙星的浓度水平导致了光降解动力学的差异，而不是成分的差异。观察到不同 pH 值和 NaCl 存在对氟罗沙星光降解的影响。低 pH 值降低了光解的效果，增强了氟罗沙星注射液的光稳定性。提出了一种新的降解产物的结构。使用发光细菌 Q67 对暴露于光后的氟罗沙星注射液进行了急性毒性试验。研究证明，氟罗沙星在稀注射液中更容易光解，并且在辐照过程中，稀注射液的急性毒性比浓注射液增加得更快。
