Souza Marines J, Kulmann Rosecler R, Silva Lucélia M, Nogueira Daniele R, Zimmermann Estevan S, Schmidt Cleber A
Centro de Desenvolvimentos de Testes e Ensaios Farmacêuticos (CTEFAR), DFI, Centro de Ciências da Saúde, Universidade Federal de Santa Maria, Santa Maria, Brazil.
J AOAC Int. 2006 Sep-Oct;89(5):1367-72.
Cefepime is a new parenteral cephalosporin that has been described as a fourth-generation, broad-spectrum antibiotic. This paper reports the development and in-house validation of an agar diffusion bioassay using a cylinder-plate method for the determination of cefepime in powder for injection. The validation performed yielded good results in terms of linearity, precision, accuracy, and robustness. The assay is based on the inhibitory effect of cefepime upon the strain of Micrococcus luteus ATCC 10240 used as the test microorganism. The results of assays were treated statistically by analysis of variance (ANOVA) and were found to be linear (r = 0.99993) in the selected range of 8.0-32.0 microg/mL; precise [repeatability: relative standard deviation (RSD) = 1.39%, intermediate precision: between-day RSD = 1.77%, and between-analyst RSD = 1.97%] and accurate. Comparison of bioassay and liquid chromatography by ANOVA showed no significant difference between methodologies. The results demonstrated the validity of the proposed bioassay, which is a simple and useful alternative methodology for cefepime determination in routine quality control.
头孢吡肟是一种新型的胃肠外给药头孢菌素，被描述为第四代广谱抗生素。本文报道了一种采用圆筒平板法测定注射用头孢吡肟粉中头孢吡肟含量的琼脂扩散生物测定法的建立及内部验证情况。所进行的验证在线性、精密度、准确度和稳健性方面均取得了良好结果。该测定法基于头孢吡肟对用作测试微生物的藤黄微球菌ATCC 10240菌株的抑制作用。测定结果通过方差分析（ANOVA）进行统计学处理，发现在8.0 - 32.0微克/毫升的选定范围内呈线性（r = 0.99993）；精密度良好[重复性：相对标准偏差（RSD）= 1.39%，中间精密度：日间RSD = 1.77%，分析人员间RSD = 1.97%]且准确度高。通过ANOVA对生物测定法和液相色谱法进行比较，结果表明两种方法之间无显著差异。结果证明了所提出的生物测定法的有效性，该方法是常规质量控制中测定头孢吡肟的一种简单且有用的替代方法。
