Flow Injection Spectrophotometric and Chromatographic Determination of Ciprofloxacin and Norfloxacin in Pharmaceutical Formulations

Original Paper

Abstract

Methods based on flow injection analysis (FIA) and high-performance liquid chromatography (HPLC) have been developed for the determination of ciprofloxacin (CIP) and norfloxacin (NOR) in pharmaceutical dosage forms. The FIA method is based on the measurement of absorbances of the red complexes formed between iron (III) and the studied drugs at 440 nm. Optimization of chemical and FI variables has been made. Under the optimized conditions, the sampling rate was over 80 h^-1. For the chromatographic method, a reverse phase Suplico LC₈ column (7.5 cm * 4.6 mm i.d, 3μm dp) was used at ambient temperature. The mobile phase finally selected was prepared by using ACN: 0.005 M H₃PO₄ (30:70) adjusted to pH = 4.98 by TEA. The developed methods have been successfully applied for the determination of ciprofloxacin and norfloxacin in pharmaceutical formulations. The common excipients and additives did not interfere in their determinations. The results obtained by the proposed methods have been statistically compared by means of Student t-test and by the variance ratio F-test.