Evaluating the greenness, blueness, and whiteness of spectroscopic and UPLC techniques for the simultaneous measurement of anti-glaucoma drugs and the preservation agent

The pursuit of sustainable solutions is increasingly crucial in contemporary times. We propose inventive research that fulfills the criteria of whiteness and greenness in analytical chemistry. The endeavor aims to advance environmentally conscious techniques for the simultaneous detection of timolol maleate (TIM), dorzolamide HCl (DOR), and benzalkonium Cl (BNZ). The first method employed a sustainable mobile phase consisting of 0.02 M phosphate buffer: ethanol (68:32, v/v), and a flow rate of 0.6 mL/min with retention times 1.274, 1.798, and 2.483 min for DOR, TIM, and BNZ, respectively, with a UV detector at 210 nm. This methodology was easy, fast, and accurate. The approach showed low processing times, peak symmetry, and satisfactory resolution, with correlation values of 0.999. The linearity was between 0.001–0.064, 0.001–0.060 µg mL^-1, and 0.001–0.050 µg mL^-1for DOR, TIM, and BNZ, respectively. Furthermore, employing water as the solvent, complementary spectrophotometric methods such as Mean Centering of Ratio Spectra (MCR) and Successive Derivative Ratio Spectra (SRDS) were investigated as economical and environmentally friendly substitutes. All procedures demonstrated good linearity (r² > 0.9990), acceptable accuracy, and precision (RSD ≤ 2 %). Furthermore, by proving the superiority of the current work over previously published methods regarding sustainability, analytical performance, economics, and practicality, the real-world implementation of four greenness and whiteness algorithms boosts the approval and overall sustainable development of the proposed methods. The suggested techniques offer low-cost, environmentally friendly substitutes for traditional methods, advancing the field of analytical chemistry towards more sustainable practices and fostering a less destructive future for quality control.