Development and Validation of UV Spectrophotometric and RP-HPCL Methods for Simultaneous Estimation of Levofloxacin and Loteprednol in their Combined Pharmaceutical Dosage Form

Abstract

A simple, sensitive, rapid, accurate and precise absorption ratio method has been developed for concurrent estimation of Loteprednol and Levofloxacin in combined dosage form. Ratio of absorbance at two selected wavelengths was calculated. First wavelength is absorption maxima of respective drug and second wavelength is isoabsorptive point at which both drugs give same absorbance. Levofloxacin shows absorbance maxima at 298.5 nm and Loteprednol shows absorbance maxima at 237.5 nm in methanol. The isoabsorptive point of Levofloxacin and Loteprednol was found to be at 269.29 nm. Linearity was constructed in the concentration range of 5-25 μg/ml. Promising values of correlation coefficient for Loteprednol (R2=0.9984) and Levofloxacin (R2=0.9990) proves that method is linear. Furthermore, the method was successfully validated in terms of various validation parameters as suggested by ICH guidelines. The developed method was successfully applied for estimation of both Loteprednol and Levofloxacin from its synthetic mixture. A simple, specific and accurate high performance liquid chromatography (HPLC) method was also developed and validated for simultaneous quantification of Levofloxacin and Loteprednol etabonate in their combined dosage form. Chromatography was performed using C8 column (Zorbax) 250 mm ×4.6 mm i.d., 5μm with Acetonitrile : ammonium acetate buffer (20 mM) added 0.5 mL TEA/500 ML adjusted to pH-3.1 by Glacial acetic acid, as mobile phase. Wavelength used was 269 nm. The gradient system was applied to separate both the drugs. Linearity was constructed in concentration range of 75 to 375 μg/ml for Levofloxacin and 25 to 125 μg/ml for Loteprednol etabonate. Promising values of correlation coefficient for Loteprednol (R2=0.997) and Levofloxacin (R2=0.999) proves that method is linear. Furthermore, the method was successfully validated in terms of various validation parameters as suggested by ICH guidelines. The developed method was successfully applied for estimation of both Loteprednol and Levofloxacin from its synthetic mixture.