State-of-the-art mathematically induced filtration approaches for smart spectrophotometric assessment of silodosin and solifenacin mixture in their new challenging formulation: Multi-tool greenness and whiteness evaluation.

Benign prostatic hyperplasia is one of the most predominant health disorders in men with increasing incidence by age and usually accompanied with other bothersome symptoms. A new fixed dose combination, containing Silodosin and Solifenacin, has been recently launched for relieving such disorder associated with overactive bladder syndrome. In the current work, three smart, innovative and white spectrophotometric methods have been newly developed and optimized for simultaneous determination of the studied drugs in their binary mixture using water as an eco-friendly solvent. The adopted strategy relied on calculation of one or two factors as numerical constant or spectrum allowing mathematical filtration of desired analyte and full removal of any overlapped components in the mixture. The developed methods are categorized over two spectrophotometric platform windows. Window I deals with absorption spectra in its native forms (zero-order) including a newly developed method termed induced concentration subtraction (ICS) as well as induced dual wavelength (IDW) methods. Whereas window III is concerned with ratio spectra as in induced amplitude modulation (IAM) method. Compared to classical spectrophotometric methods, the proposed ones are superior in overcoming the inherited challenges in zero-order absorption spectrum of Solifenacin, particularly its very low absorptivity and lack of unique absorption maximum. Validity of the methods were thoroughly assured as per ICH guidelines with unified regression over 3.0-50.0 µg/mL in ICS method while IDW and IAM ones possessed linearity ranges of 3.0-50.0 µg/mL of Silodosin and 5.0-60.0 µg/mL of Solifenacin. The work was also extended to verify content uniformity of dosage units in accordance with USP recommendations. Greenness profile of the proposed methods was clearly assessed, in comparison to the reported analysis ones, via state-of-the-art software metrics, namely, green solvent selection tool (GSST), complementary green analytical procedure index (ComplexGAPI) and analytical greenness (AGREE). Finally, the proposed methods were in good adherence to the recently published postulates of white analytical chemistry.