Development of a stability indicating HPLC-DAD method for the simultaneous determination of mometsone furoate and salicylic acid in an ointment matrix

A validated stability-indicating method has been developed for the simultaneous determination of mometsone furoate (MOM) and salicylic acid (SAA) in a combined dosage form. This method is based on the reversed-phase high performance liquid chromatographic (HPLC) separation of the cited drugs. The HPLC separation was performed on a RP Zobrax Eclipse XDB-C8 analytical column (150 x 4.6 mm, 5 mu m) with isocratic elution with a mobile phase of methanol and 0.02 M aqueous phosphate buffer (70 : 30) adjusted to pH 2.3 and a flow rate of 1.5 mL min(-1). Quantitation was achieved by means of photodiode array detection (DAD) at 260 nm. The calibration graphs for each drug were rectilinear in the range of 0.25-15 and 12.5-750 mu g mL(-1) for MOM and SAA, respectively using dexamethasone acetate as the internal standard. The proposed HPLC-DAD method was successfully applied in the determination of the investigated drugs in ointment. The method was validated in compliance with ICH guidelines, in terms of linearity, accuracy, precision, robustness, limits of detection and quantitation and specificity.