Quantitative proton nuclear magnetic resonance method for simultaneous analysis of fluticasone propionate and azelastine hydrochloride in nasal spray formulation

A facile, rapid, accurate and selective quantitative proton nuclear magnetic resonance ((1)H-qNMR) method was developed for the simultaneous determination of fluticasone propionate (FLP) and azelastine hydrochloride (AZH) in pharmaceutical nasal spray for the first time. The (1)H-qNMR analysis of the studied analytes was performed using inositol as the internal standard and dimethyl sulfoxide-d(6) (DMSO-d(6)) as the solvent. The quantitative selective proton signal of FLP was doublet of doublet at 6.290, 6.294, 6.316 and 6.319 ppm, while that of AZH was doublet at 8.292 and 8.310 ppm. The internal standard (inositol) produced a doublet signal at 3.70 and 3.71 ppm. The method was rectilinear over the concentration ranges of 0.25–20.0 and 0.2–15.0 mg ml(−1) for FLP and AZH, respectively. No labelling or pretreatment steps were required for NMR analysis of the studied analytes. The proposed (1)H-qNMR method was validated efficiently according to the International Council on Harmonisation guidelines in terms of linearity, limit of detection, limit of quantification, accuracy, precision, specificity and stability. Moreover, the method was applied to assay the analytes in their combined nasal spray formulation. The results ensured the linearity (r(2) > 0.999), precision (% RSD < 1.5), stability, specificity and selectivity of the developed method.