Validated HPTLC and Stability Indicating RP-HPLC Methods for the Simultaneous Estimation of Moxifloxacin and Dexamethasone in Bulk and Ophthalmic Dosage Form

Novel HPTLC and stability indicating RP-HPLC methods were developed for simultaneous estimation of Moxifloxacin (MOX) and Dexamethasone (DEX) in ophthalmic dosage form. For HPTLC method, the separation was carried out on HPTLC aluminum plates using acetonitrile:water:ammonia (8:1:0.5 v/v/v) as mobile phase and developed plates were read at 266 nm. The drugs were resolved satisfactorily with Rf values of 0.09±0.01 and 0.74±0.01 for MOX and DEX, respectively. The RP-HPLC analysis is carried out on Shiseido C18 column (250 mm × 4.6 mm I.D., 5 µm), using 0.02M acetate buffer (pH is 4 adjusted with triethylamine) and acetonitrile in the ratio of 60:40 v/v with a flow rate of 1.2 m/min and the detection was carried out at 254 nm. The retention times were found to be 2.144±0.5 min and 4.732±0.5 min. for MOX and DEX respectively. Developed methods were validated as per ICH guidelines and were found to be within the limits.