Gortázar P, Vázquez J T
Centro de Productos Naturales Orgánicos Antonio González, Universidad de La Laguna-C.S.I.C., Tenerife, Spain.
J Pharm Sci. 1994 Sep;83(9):1204-8. doi: 10.1002/jps.2600830903.
The circular dichroism and ultraviolet spectra of 15 commercial cephalosporins in common clinical use are analyzed. Distinguishing between the beta-lactam antibiotics (penicillins, cephalosporins, and cephamycins) on the basis of their CD spectral data has been found to be straightforward. Furthermore, sufficient CD spectral dissimilarities are observed to discriminate among the cephalosporin homologues and to classify these antibiotics in five spectroscopic groups, on the basis of the wavelengths of their Cotton effects. In addition, some chemical structural characteristics for these spectroscopic groups are discussed. Besides molar absorptivity and CD data, the slopes and the intercepts of the equations of the regression line are calculated for each of these antibiotics, the correlation coefficients being higher than 0.9993. The validity of the proposed model is confirmed by analysis of the variance. The results demonstrated that the proposed method is accurate and precise. The method was successfully applied to the direct determination of these drugs in commercial oral suspensions, injections, and capsules. The principal advantages of this method are quickness and simplicity no derivatization or chromatographic separation steps being needed.
对15种临床常用的市售头孢菌素的圆二色光谱和紫外光谱进行了分析。已发现根据β-内酰胺抗生素（青霉素、头孢菌素和头霉素）的圆二色光谱数据进行区分很简单。此外，观察到足够的圆二色光谱差异，以便根据头孢菌素同系物的科顿效应波长在它们之间进行区分，并将这些抗生素分为五个光谱组。此外，还讨论了这些光谱组的一些化学结构特征。除了摩尔吸光率和圆二色光谱数据外，还计算了每种抗生素的回归线方程的斜率和截距，相关系数高于0.9993。通过方差分析证实了所提出模型的有效性。结果表明所提出的方法准确且精密。该方法已成功应用于市售口服混悬剂、注射剂和胶囊中这些药物的直接测定。该方法的主要优点是快速且简单，无需衍生化或色谱分离步骤。
