Eco-friendly method by Eco-Scale Assessment for quantification of tinidazole in tablets

• Tinidazole is an antimicrobial marketed in tablet form. • It presents a monograph in official compendiums by titration. • UV stability indicator method for tinidazole tablets was developed. • According to ESA, the proposed method is considered an excellent green analysis. • The greenness of the analytical process was 90. Tinidazole (TIN), an antimicrobial, is commonly prescribed for the treatment of giardiasis, trichomoniasis and amoeba infections. It presents a monograph in official compendiums by titration and the literature presents some analytical methods, which mostly use methanol and acetonitrile, options opposed to the principles of Green Analytical Chemistry (GAC) and the current trend in chemical-pharmaceutical analyses. Among the principles of GAC, the generation of less waste, the choice of less toxic reagents and solvents, the use of fewer materials, the assessment of costs involved, faster steps and processes are included. In this context, the objective was to develop and validate an eco-friendly method by spectrophotometry in ultraviolet region (UV) for quantitative evaluation of TIN in tablets. Additionally, the proposed method was evaluated for greenness by the Eco-Scale Assessment (ESA). Purified water and ethanol (90:10, v/v) as a diluent, quartz cubette at 318 nm were used. The method was linear in the range of 7–22 µg/mL (0.9999), precise (RSD < 5 %), selective through sample adjuvants and by the forced degradation, exact (100.47 %) and robust against changes in reading wavelength. As for the greenness of the method, it proved to be a green alternative to quantify TIN in tablets according to the ESA.