A New Extractive Spectrophotometric Method for the Determination of Gatifloxacin and Cefotaxime Sodium in Pure and Pharmaceutical Dosage Forms

Simple, accurate, precise, and rapid extractive spectrophotometric method was developed for the estimation of gatifloxacin (I) and cefotaxime sodium (II) in both pure and pharmaceutical dosage forms. The method was based on the formation of colored complex by the drugs with Eriochrome black-T in an acidic medium. The ion-associated complex formed was quantitatively extracted under the experimental conditions with methylene chloride and the absorbances of the organic layers were measured at 510 nm. Beer's law was obeyed in the concentration range of (318) and (30-120) ig.ml(-1) for drug (I) and (II) respectively. The correlation coefficient (r(2)) for the studied drugs was found to be 0.9999. The molar absorptivity (mu), sandell sensitivity, detection (LOD) and quantitation limits (LOQ) were also calculated. The proposed method was successfully applied for the determination of certain pharmaceutical dosage forms containing the studied drugs.