el Walily A F, Belal S F, Bakry R S
Pharmaceutical Analytical Chemistry Department, College of Pharmacy, University of Alexandria, Egypt.
J Pharm Biomed Anal. 1996 Mar;14(5):561-9. doi: 10.1016/0731-7085(95)01662-7.
Spectrophotometric and spectrofluorimetric methods for the determination of two broad-spectrum fluoroquinolone antibacterials (ciprofloxacin and norfloxacin), either in pure form or in tablets, are described. Both methods are based on the formation of a ternary complex between palladium(II), eosin and the fluoroquinolone in the presence of methyl cellulose, as surfactant. Spectrophotometrically, under the optimum conditions, the ternary complexes showed an absorption maximum at 545 nm, with apparent molar absorptivities of 3.4 x 10(4) and 2.7 x 10(4) 1 mol-1 cm-1 and Sandell's sensitivities of 1.01 x 10(-2) and 1.12 x 10(-2) micrograms cm-2 for ciprofloxacin and norfloxacin, respectively. The solution of the ternary complex obeyed Beer's law in the concentration range 3-10 micrograms ml-1 for both quinolones. The proposed method was applied to the determination of the two drugs in pharmaceutical tablets. A fluorescence quenching method for the determination of both quinolones by forming this ternary complex was also investigated for the purpose of enhancing the sensitivity of the determination. The results obtained by the application of both procedures and the USP XXIII methods were in good agreement and statistical comparison by means of Student's t-test and the variance ratio F-test showed no significant differences between the three methods.
本文描述了分光光度法和荧光分光光度法，用于测定两种广谱氟喹诺酮类抗菌药物（环丙沙星和诺氟沙星），它们可以是纯品形式，也可以是片剂形式。两种方法均基于在甲基纤维素作为表面活性剂存在的情况下，钯（II）、曙红与氟喹诺酮形成三元络合物。在分光光度法中，在最佳条件下，三元络合物在545nm处有最大吸收，环丙沙星和诺氟沙星的表观摩尔吸光系数分别为3.4×10⁴和2.7×10⁴L·mol⁻¹·cm⁻¹，桑德尔灵敏度分别为1.01×10⁻²和1.12×10⁻²μg·cm⁻²。两种喹诺酮类药物的三元络合物溶液在3 - 10μg·ml⁻¹浓度范围内均符合比尔定律。所提出的方法应用于药物片剂中两种药物的测定。还研究了通过形成这种三元络合物来测定两种喹诺酮类药物的荧光猝灭法，以提高测定的灵敏度。应用这两种方法和美国药典XXIII方法所获得的结果吻合良好，通过学生t检验和方差比F检验进行的统计比较表明，这三种方法之间没有显著差异。
