Souza Marinês J E, Rolim Clarice M B, Melo Janine, Souza Filho Paulo S, Bergold Ana M
Universidade Federal do Rio Grande do Sul (UFRGS), Faculdade de Farmácia, Programa de Pós-Graduação em Ciências Farmacêuticas, Porto Alegre, RS, Brazil.
J AOAC Int. 2007 Nov-Dec;90(6):1724-8.
Ceftiofur sodium is a third-generation broad-spectrum cephalosporin antibiotic, formulated as an intramuscular injection, that is approved for use in pigs, cattle, poultry, and dogs. The present work reports a method to quantify ceftiofur in powder for injection by comparing the cylinder plate assay and the liquid chromatographic (LC) method. The assay is based on the inhibitory effect of ceftiofur upon the strain of Micrococcus luteus ATCC 10240 used as the test microorganism. Ceftiofur sodium at concentrations ranging from 2.0 to 8.0 microg/mL can be measured in powder for injection. A prospective validation showed that the method is linear (r2 = 0.9998), with precise relative standard deviation (RSD) of 0.8% for product A (Excenel; Pharmacia and Upjohn Co., Kalamazoo, MI) and of 0.6% for product B (Topcef; Eurofarma Lab. Ltda, São Paulo, Brazil), with intermediate precision; between-day RSD = 1.0 and 1.1%, between-analyst RSD = 0.8 and 0.8% for products A and B, respectively and accurately. The comparison between bioassay and LC by analysis of variance and Student's t-test showed no significant difference among methodologies. The results demonstrated the validity of the proposed bioassay that is simple and a useful alternative methodology for analysis of ceftiofur in routine quality control.
头孢噻呋钠是一种第三代广谱头孢菌素抗生素，制成肌内注射剂，已被批准用于猪、牛、家禽和犬类。本研究报告了一种通过比较管碟法和液相色谱（LC）法来定量注射用粉末中头孢噻呋的方法。该测定基于头孢噻呋对用作测试微生物的藤黄微球菌ATCC 10240菌株的抑制作用。注射用粉末中浓度范围为2.0至8.0微克/毫升的头孢噻呋钠可被测定。前瞻性验证表明该方法呈线性（r2 = 0.9998），产品A（Excenel；辉瑞制药公司，密歇根州卡拉马祖）的相对标准偏差（RSD）精确为0.8%，产品B（Topcef；巴西圣保罗Eurofarma Lab. Ltda）的相对标准偏差为0.6%，具有中间精密度；产品A和B的日间RSD分别为1.0%和1.1%，分析人员间RSD分别为0.8%和0.8%，且结果准确。通过方差分析和学生t检验对生物测定法和LC法进行比较，结果表明各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，该方法简单，是常规质量控制中分析头孢噻呋的一种有用的替代方法。
