Eco-friendly resolution of spectrally overlapping signals of a combined triple-action over-the-counter pharmaceutical formulation for symptomatic management of COVID-19 pandemic: application to content uniformity testing.

Currently, all researchers are concentrating their efforts on countering the COVID-19 pandemic. The majority of patients are managed at home, according to recent statistics. An OTC triple action combination comprising paracetamol (PAR), aspirin (ASP), and diphenhydramine (DIPH) is commonly given for pain relief, fever control, and as a night-time sleep aid. This combination is currently recommended for COVID-19 patients as part of symptomatic treatment and management. In this work, three smart, simple, accurate, eco-friendly, and cost-effective spectrophotometric methods are developed for simultaneous determination of PAR, ASP, and DIPH in their combined over-the-counter caplet dosage form without any prior separation steps. The first method is the first derivative spectrophotometry (D) which determined PAR at 259.7 nm. The second one is the dual-wavelength in ratio spectra (DWRS) for determination of ASP at 214.1 and 220.1 nm after using 10.0 μg/mL of PAR as a divisor, where PAR was a constant, and the wavelengths difference equal to zero for DIPH. The third method is the double divisor-ratio difference spectrophotometric one (DD-RD) which was based on using the sum of 15.0 µg/mL of each of PAR and ASP as a double divisor, and the difference in amplitudes was measured at two wavelengths ∆P for determination of DIPH. The developed methods have been validated as per ICH guidelines. Furthermore, the three suggested methods were employed successfully to assay marketed pharmaceutical formulation and to investigate the content uniformity of the dosage units in accordance with the United States Pharmacopeia's guidelines. Finally, the greenness profile of the proposed methods was assessed and compared with the reported method using the analytical eco-scale system, national environmental method index (NEMI), green analytical procedure index (GAPI), and analytical greenness (AGREE) metric. The results from the proposed methods statistically agreed with those obtained by the reported one, with no significant differences in accuracy and precision.