Original Articles: 2011 Vol: 3 Issue: 6
Validated Stability Indicating Assay of Gemifloxacin by different Chromatographic and Spectrophotometric methods of analysis
Two chromatographic and three spectrophotometric methods have been developed for the determination of gemifloxacin (GF) in bulk powder and pharmaceutical preparations. The first method depends on RP-HPLC, separation of drug and its degradation products was successfully achieved on a Hypersil BDS C18 column using mobile phase consisted of citrate buffer (adjusted to 2.5 pH by citric acid):Acetonitrile (70:30, v/v) at 1 ml/min flow rate and 267 nm wavelength of detection. The second method which achieved successful separation of drug and its degradation products depends on TLC densitometry using a developing system consisted of chloroform : methanol : toluene : diethylamine : water (33.6:33.6:16.8:10.8:6,by volume) with 20 μl spotting volume and 260 nm wavelength of detection. Three UV methods have been developed for GF estimation in presence of its degradation products as stability indicating techniques. These methods are first derivative (D1), first derivative of ratio spectra (DD1) and second derivative of the difference absorption ( D2) of acidic GF solutions in 0.1N HCl against its alkaline solutions in 0.1N NaOH as blanks. All the proposed methods were validated and successfully applied for determination of GF in pure form and in pharmaceutical preparations with good recovery. The results obtained by applying the proposed methods were statistically analyzed and compared with those obtained by the manufacturer method and no significant difference was found.