A fixed dose combination of levofloxacin hemihydrate (quinolone antibiotic) and cefpodoxime proxetil (cephalosporin) was used in ratio of 1:1.25 as tablet for the treatment of resistant lower respiratory tract and other infections. A simple, precise and accurate stability indicating reverse-phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for determination of levofloxacin hemihydrate (LVF) and cefpodoxime proxetil (CPD) in tablet dosage form. Isocratic RP-HPLC separation was achieved on an ACE C18 column (150 × 4.6 mm id, 5 µm particle size) using the mobile phase consists a mixture of 0.5% (v/v) triethylamine in 25 mM Sodium dihydrogen ortho-phosphate dihydrate buffer (pH 6.0)–methanol (52:48 v/v) at a flow rate of 1.0 ml/min. The retention time of levofloxacin hemihydrate and isomers of cefpodoxime proxetil were 4.7 min and 9.6, 11.6 min, respectively. The detection was performed at 273 nm. The method was validated for linearity, precision, accuracy, robustness, solution stability and specificity. The method was linear in the concentration range of 6.25–37.5 µg/ml for levofloxacin hemihydrate and 5–30 µg/ml for cefpodoxime proxetil, with a correlation coefficient of 0.9999 and 0.9999 for the respective drugs. The accuracy (recovery) was found to be in the range of 98.56-100.16% and 99.1–100.81% for levofloxacin hemihydrate and cefpodoxime proxetil, respectively. Levofloxacin hemihydrate was only degraded under oxidative conditions while cefpodoxime proxetil was degraded in all conditions. The drugs could be effect effectively separated from different degradation products and hence the method can be used for stability analysis.
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