Determination of ofloxacin and dexamethasone in Dexaflox eye drops through different ratio spectra manipulating methods

•Ofloxacin and Dexamethasone in combination in eye drops.•Ofloxacin determined simply by zero order.•Dexamethasone determined by 1DD at 266.5 nm and mean centering at 243 nm.•Ratio subtraction technique was applied for the determination of Dexamethasone in its laboratory prepared mixtures.

Different sensitive and selective spectrophotometric methods for the determination of ofloxacin and dexamethasone in their binary mixture were presented. Ofloxacin was determined simply by zero order at its λmax 293.4 nm in a linear range of 1.5–12 μg mL−1 with mean percentage recovery of 100.07 ± 0.66% without any interference of dexamethasone even in low or high concentrations. Dexamethasone was determined by first derivative of ratio spectra 1DD at 266.5 nm, ratio subtraction and mean centering at 243 nm with methods in a linear range of 2.5–27.5 μg mL−1 with mean percentage recoveries of 100.09 ± 0.70%, 100.00 ± 0.72% and 99.92 ± 0.62, respectively. These methods were applied to the analysis of pharmaceutical dosage form and bulk powder where good recoveries were obtained. The proposed methods were validated according to USP guidelines.

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