NOVEL FORMATION THREE COMPLEXES OF CEFIXIME-COPPER USING ACETATE–ACETIC ACID BUFFER AND DETERMINATION OF CEFIXIME IN PURE AND PHARMACEUTICAL DOSAGE FORMS

摘要

Novel formation three complexes of cefixime-copper using acetate–acetic acid buffer at pH4.8 and determination of cefixime in pure and pharmaceutical dosage forms in methanol (96%, v) has been developed. Optimal temperature and time for coupling were established at 50±1oC with time 25min. The formation complexes, CEFI:Cu(II) gives, in the first time, three forms; the first one is [(CEFI)2(Cu).2HCl], the second is [(CEFI)(Cu).HCl] and the third [(CEFI)(Cu)2.2HCl]. The reaction between CEFI and Cu(II) occurred at stoichiometric ratio of 2:1, 1:1 and 1:2, respectively. The maximum absorbance of the complexes occurred at λ= 510, 500 and 450 nm. The molar absorptivity is 1.52 x 103, 1.06 x 103and 3.42 x 103L.mol-1.cm-1, respectively. All reaction conditions have been optimized to obtain the complexes. Under optimum conditions Beer's law was obeyed at concentrations ranging from 0.4535 to 18.138 μg.mL-1with correlation coefficients ≥0.9980 in all cases with RSD generally less than 4.8%. The limit of detection (LOD) and limit of quantification (LOQ) was found to be 0.036 μg.mL-1and 0.109 μg.mL-1, respectively. The proposed method was novel, simple, accurate and successfully applied to the determination of CEFI in pharmaceuticals with average recovery of 96.59 to 102.16%, the results obtained agree well with the contents stated on the labels