The development of analytical techniques is required for the accurate and comprehensive detection and measurement of antibiotic contamination in the environment. Metronidazole is a common antibacterial, antiprotozoal, and antibiotic drug. Thiamine is a vital biological and medicinal ingredient that is involved in the metabolism of proteins, fats, and carbohydrates that produce energy. The study aims to identify the drugs in a mixture without separation to provide more information to confirm if a drug is present in a combination. Metronidazole and thiamine are two examples of pharmaceutical and environmental samples that can be identified using spectrophotometric techniques because of their low cost and simplicity of use. The operating solutions of both drugs were used to scan the UV spectrum between 200 and 400 nm, and the corresponding overlay spectra of the two drugs were recorded. The best absorption peak at 264 nm is exhibited by thiamine, which is observed in the presence of metronidazole with the peak at 320 nm in the suggested method. The working curve for metronidazole and thiamine was set to obey the Beer – Lambert law in the range of (1 – 15) μg/mL for each of them, with molar absorptivity values of 12716.89 and 2053.22 liter/mol/cm for metronidazole and thiamine, respectively. Thiamine and metronidazole showed results in the recovery study that ranged from 99.1 to 100% across three concentrations. For thiamine and metronidazole, the precision study was conducted using estimates of
