SPECTROPHOTOMETRIC DETERMINATION OF OFLOXACIN IN PHARMACEUTICALS BY REDOX REACTION
<i>Two simple spectrophotometric methods have been developed to analyze ofloxacin (OFX) in pharmaceuticals. The methods are based on the oxidation of OFX by a measured excess of cerium(IV) sulphate in an H</i><sub><i>2</i></sub><i>SO</i><sub><i>4</i></sub><i> medium. This was followed by the determination of the unreacted oxidant by reacting it with either p-toluidine (p-TD) and measuring the absorbance at 525 nm (method A) or o-dianisidine (o-DA) and measuring the absorbance at 470 nm (method B). In both methods, the amount of cerium(IV) sulphate reacted corresponds to the amount of OFX. Calibration graphs were linear over the ranges of 0-120 and 0-4 µg/ml OFX for the methods A and B, respectively. The calculated molar absorptivity (2.34 · 10</i><sup><i>3</i></sup><i> and 5.99 · 10</i><sup><i>4</i></sup><i>), Sandell sensitivity, and limit of quantification for the methods are reported. The intra-day precision (%RSD) and accuracy (%RE) were <8.0 and ≤4.0 %, respectively, and the inter-day RSD and RE values were within 5 and 4.0 %, respectively. The applicability of the methods was demonstrated by determining OFX in tablets with an accuracy (%RE) of < 3% and precision (%RSD) of ≤2.65 %. The accuracy of the methods was further ascertained by recovery experiments via a standard-addition procedure.</i>