Design of resonance Rayleigh scattering and spectrofluorimetric methods for the determination of the antihistaminic drug, hydroxyzine, based on its interaction with 2,4,5,7‐tetraiodofluorescein: Evaluation of analytical eco‐scale and greenness/whiteness algorithms

In this work, two validated approaches were used for estimating hydroxyzine HCl for the first time using resonance Rayleigh scattering (RRS) and spectrofluorimetric techniques. The suggested approaches relied on forming an association complex between hydroxyzine HCl and 2,4,5,7‐tetraiodofluorescein (erythrosin B) reagent in an acidic media. The quenching in the fluorescence intensity of 2,4,5,7‐tetraiodofluorescein by hydroxyzine at 551.5 nm (excitation = 527.5 nm) was used for determining the studied drug by the spectrofluorimetric technique. The RRS approach is based on amplifying the RRS spectrum at 348 nm upon the interaction of hydroxyzine HCl with 2,4,5,7‐tetraiodofluorescein. The spectrofluorimetric methodology and the RRS methodology produced linear results within ranges of 0.15–1.5 μg ml−1 and 0.1–1.2 μg ml−1, respectively. LOD values for these methods were determined to be 0.047 μg ml−1 and 0.033 μg ml−1, respectively. The content of hydroxyzine HCl in its pharmaceutical tablet was estimated using the developed procedures with acceptable recoveries. Additionally, the application of four greenness and whiteness algorithms shows that they are superior to the previously reported method in terms of sustainability, economics, analytical performance, and practicality. Hydroxyzine interacts with erythrosin B in an acidic medium to form a binary complex. Resonance Rayleigh scattering and Spectrofluorimetric methods were developed to determine hydroxyzine. The greenness and whiteness of the developed methods have been evaluated.