RP-HPLC method for simultaneous estimation of tobramycin and dexamethasone in eye drop

RP-HPLC method has been developed and validated for simultaneous estimation of Tobramycin and Dexamethasone in eye drop. The chromatographic separation was carried out isocratically on Agilent Zorbax SB Aqueous C-18 column (250x4.6mm, 5µm) using a 0.1% Formic Acid Water: Acetonitrile (60:40% v/v) as mobile phase at flow rate of 1ml/min and detected by using photo diode array detector at 210nm. The retention times were 1.9 and 4.2 min for tobramycin and dexamethasone respectively. Linearity was obtained in the range of 240–360µg/ml and 80–120µg/ml for tobramycin and dexamethasone respectively. The developed method was validated according to ICH guidelines for specificity, linearity, range, accuracy, precision, system suitability parameters. The proposed method was found to be specific, accurate and precise. This method can be employed for routine analysis of simultaneous estimation of tobramycin and dexamethasone in eye drop.