Validated Stability-indicating Reverse-phase Ultra-performance Liquid Chromatography Method for Simultaneous Determination of Sodium Methylparaben, Sodium Propylparaben and Ketorolac Tromethamine in Topical Dosage Forms

A sensitive, fast, and stability-indicating isocratic reverse-phase ultra-performance liquid chromatography method was developed and validated for quantitative simultaneous determination of sodium methylparaben, sodium propylparaben and ketorolac tromethamine in topical dosage forms. Separation of all peaks was achieved by using acquity ethylene bridged hybrid C18 (50×2.1 mm, 1.7 μ) as stationary phase, mobile phase used was triethylamine buffer (pH 2.5):tetrahydrofuran:methanol (665:35:300, v/v/v) with isocratic mode at a flow rate of 0.40 ml/min. All component were detected at 252 nm with 10 min run time. The described method was found to be linear in the concentration range of 248-744 μg/ml for ketorolac tromethamine, 20.8-62.4 μg/ml for sodium methylparaben and 2.38-7.13 μg/ml for sodium propylparaben with correlation coefficients more than 0.999. Method was validated in terms of specificity, linearity, accuracy, precision, solution stability, filter equivalency, and robustness as per International Conference on Harmonization guideline. Formulation was exposed to the stress conditions of peroxide, acid, base, thermal, and photolytic degradation and proven all components were well separated in the presence of degradants.