Determination of levofloxacin in pharmaceutical formulationtavanic by visible spectrophotometry of its chelating complex with aluminum ion

A simple, sensitive and accurate spectrophotometric method has been developed for the analysis of levofloxacin (LEV) in pharmaceutical formulations, through formation of yellow-greenish chelating complex LEV-Al(III) of levofloxacin with aluminum (III) ion. The maximum absorbance (420)nm. Different variables affecting the reaction were carefully studied. The optimum concentration for metal ion (28)µg ml-1, optimum temperature for the reaction (60) C0and optimum time for the reaction (5) min Under optimized conditions, linearity was observed in the range of 5-45 g mL-1 with detection limit (S/N) of 0.064 g mL-1, precision in range of 0.93-1.51 % , accuracy as the % Erel of 1.16%,  and recoveries ranged from 100.83 to 101.65 % with mean value of 101.16 ± 0.84. The proposed method was applied for the determination of LEV in the drug Tavanic by both direct calibration and standard additions procedures and found to be 4.95 and 4.89 mg per mL, respectively compared with the stated value of 5 mg per mL. All statistical calculations were implemented via the chem. software Minitab version 11.