TITRIMETRIC ASSAY OF OFLOXACIN IN PHARMACEUTICALS USING CERIUM(IV) SULPHATE AS AN OXIDIMETRIC REAGENT

摘要

Two titrirnetric methods which are simple, rapid, cost-effective and eco-riendly are described for the deter-mination of ofloxacin (OFX) in bulk drug and in tablet formulations based on the oxidation of OFX by Ce(IV) sulphate. In direct titrimetry (method A), the acidified solution of OFX is titrated directly with Ce(IV) sul-phate using ferroin as indicator, and indirect titrimetry (method B) involves the addition of known excess of Ce(IV) sulphate to an acidified solution of OFX followed by the determination of unreacted oxidant by back ltration with ferrous ammonium sulphate (FAS) using the same ferroin indicator. In both the methods, the amount of Ce(IV) sulphate reacted corresponds to OFX concentration. Method A and method В permit the determination of OFX over the concentration range of 1.5—15 mg in both the methods and the quantitation is based on a 1 : 5 reaction stoichiometry (OFX : Ce(IV) sulphate). The methods were statistically evaluated У calculating percent relative error (%RE) foraccuracy and percent relative standard deviation (% RSD) for precision, and were applied successfully to the detennination of OFX in tablets with mean recoveries in the range of 96.50-98.42%. No interference was observed from common additives found in pharmaceutical preparations. The accuracy and reliability of the methods were further ascertained by performing recovery tests via standard-addition technique.