Fluorescence based methodology with greenness consideration for concurrent estimation of anti-allergic medication; application to dosage form.

A green, sensitive and rapid spectrofluorimetric method for quantitative assay of an anti-allergic medication composed of montelukast and fexofenadine mixture in raw materials and dosage form was developed. The method was based on measuring the synchronous fluorimetric peak without interference, pre-separation or pre-extraction procedures. Montelukast was analyzed at 360 nm while fexofenadine was measured at 263 nm using Δλ = 20 nm for both drugs using ethanol as diluting solvent and acetate buffer of pH 4. The assay was rectilinear over the concentration range of 1.0-10.0 μg/mL for fexofenadine and 0.1-0.6 μg/mL for montelukast. The method was full validated according to ICH guidelines. The applicability of the method enables the assay of both drugs in raw materials, synthetic mixture as well as combined tablets. Moreover, the greenness of the method was assessed using different methods including; analytical eco-scale, GAPI and AGREE. All of these methods confirm that the proposed method is an eco-friendly method.