High-performance liquid chromatographic method for the assay of dexamethasone and xylometazoline in nasal drops containing methyl p-hydroxybenzoate

A rapid and sensitive high-performance liquid chromatographic method has been developed for the determination of dexamethasone sodium phosphate (DSP), xylometazoline hydrochloride (XMC) and methyl p-hydroxybenzoate (MHB). An assay of the compounds has been performed on a HPLC system GBC 1210, at controlled room temperature, on a Nucleosil C8 column (250×3 mm, 5 μm). The mobile phase was acetonitrile–water (35:65, v/v), at a flow-rate of 1 ml min−1. The parameters for validation such as linearity (r>0.9996), precision (RSD: 0.51–(1.93%), limit of detection and quantification (2.032·10−4 and 4.063·10−4 mg ml−1 for DSP, 9.7·10−5 and 1.953·10−4 mg ml−1 for XMC, 1.953·10−4 and 3.096·10−4 mg ml−1 for MHB) have also been reported. The method was applied to the determination of DSP, XMC and MHB in nasal drops. The statistical parameters were found to be satisfactory, with recovery values ranging from 98.69 to 101.60% (RSD: 0.32–1.03%). The method is simple and accurate and therefore suitable for the simultaneous determination of these compounds in dosage form.