A novel RP-HPLC method for the simultaneous quantification of azithromycin and dexamethasone in marketed ophthalmic drops

A straightforward, precise, accurate, specific, and sensitive RP-HPLC technique has been established for the quantification of Azithromycin Dihydrate and Dexamethasone Sodium Phosphate in their commercial formulation. The wavelength maxima for Azithromycin and Dexamethasone were considered to be 215 nm for estimation. In RP-HPLC separations were carried out on a Zorbax SB C18 column (250mm X 4.6mm, 5 μm) and mobile phase consisting of Acetonitrile: Monobasic Potassium Phosphate (KH2PO4) buffer in the proportion of 75:25 v/v and pH of the buffer was adjusted to 5.5 with OPA. The estimation was carried out at 215 nm using UV detector keeping the flow rate of 1.2 ml/min and injection volume of 50 μl. The current method demonstrates good linearity over the range of 20 - 120 μg/ml and 2 - 12 μg/ml for Azithromycin and Dexamethasone respectively. No interference of excipients was found during estimation. The recommended techniques were verified and determined to be specific, accurate, and exact. The approaches were effectively used for the concurrent quantification of both medicines in pharmaceutical formulations, making them suitable for regular quality control examination.