A VALIDATED STABILITY INDICATING RP-HPLC METHOD FOR SIMULTANEOUS DETERMINATION OF TOBRAMYCIN AND CEFTAZIDIME IN PHARMACEUTICAL FORMULATIONS

N.V.V. Jagan Mohan Reddy* and S. Ganapaty

The proposed study, a new stability- indicating RP-HPLC method has been developed for estimation of Tobramycin and Ceftazidime in bulk and pharmaceutical dosage form. The present method was a sensitive, precise, and accurate RP-HPLC method for the analysis of Tobramycin and Ceftazidime. To optimize the mobile phase, various combinations of buffer and organic solvents were used on Hypersil BDS C18 (250mm X 4.6 mm, 5μ) column. Then the mobile phase containing a mixture of Phosphate Buffer:Acetonitrile in the ratioof 55:45%v/v was selected at a flow rate of 1.0 ml/min for developing the method and the peaks with good shape and resolution were found resulting in short retention time, baseline stability and minimum noise. The retention times of Tobramycin and Ceftazidime were found to be 4.255 and 2.823 min respectively. Quantitative linearity was obeyed in the concentration range of 7.5-30 and 62.5-375 μg/mL of Tobramycin and Ceftazidime respectively. The limit of detection and limit of quantitation were found to be 0.020 μg/mL and 0.061μg/mL (TOBRA); 0.246 μg/ mL and 0.746 μg/mL (CEFTA) respectively, which indicates the sensitivity of the method. The high percentage recovery indicates that the proposed method is highly accurate. No interfering peaks were found in the chromatogram indicating that excipients used in injection formulations didn’t interfere with the estimation of the drugs by the proposed HPLC method.