SIMULTANEOUS DETERMINATION OF MOXIFLOXACIN HYDROCHLORIDE AND DIFLUPREDNATE BY RATIO DERIVATIVE SPECTROPHOTOMETRY Original Article

Objective: Ratio derivative spectrophotometric method has been developed for the simultaneous determination of Moxifloxacin HCl (MH) and Difluprednate (DIFLU) in Phosphate Buffer pH 7.4. Methods: In this method, the overlapping spectra of MH and DIFLU were well resolved by making use of the first-derivative of the ratios of their direct absorption spectra. The derivative ratio absorbances of MH and DIFLU were measured at λmax 325.8 and λmax 238.0 nm, respectively for their quantification. MH and DIFLU were determined in the concentration range of 2-10 μg/ml and 4-20 μg/ml respectively. Results: The method was validated as per the ICH guideline and accuracy, precision are found to be within the acceptable limit. The limits of detection and quantitation were found to be 0.1144 and 0.3466 μg/ml, respectively for MH and 0.0311 and 0.094 μg/ml, respectively for DIFLU. Conclusion: The proposed ratio first derivative spectrophotometric method is novel, rapid, simple, sensitive, accurate, precise and does not require separation of MH and DIFLU hence successfully applied for simultaneous estimation of MH and DIFLU in marketed eye drops (liquid dosage form).