Green HPLC method for tinidazole determination in tablets: Sustainability and applicability assessment

Tinidazole is a nitroimidazole antimicrobial agent used to treat protozoal and anaerobic bacterial infections. Ensuring the quality of its pharmaceutical formulations requires reliable analytical methods that combine appropriate analytical performance with environmental sustainability and practical applicability. However, the integration of these attributes in chromatographic methods for tinidazole determination in tablets remains insufficiently explored. Therefore, this study aimed to develop and validate a green high-performance liquid chromatography (HPLC) method for tinidazole determination in tablets, incorporating complementary greenness and applicability assessments. Chromatographic separation was performed using a C18 column (150 × 4.6 mm, 5 µm) and a mobile phase consisting of purified water and ethanol (80:20, v/v), at a flow rate of 0.8 mL/min, an injection volume of 20 µL, and detection at 318 nm. The method demonstrated selectivity against pharmaceutical excipients and was evaluated under forced degradation conditions, with a retention time of 2.9 min. Linearity was established over the range of 1–10 µg/mL, with satisfactory intraday, interday, and interanalyst precision (relative standard deviations of 0.58%, 0.84%, and 1.23%, respectively) and accuracy (mean recovery of 100.39%). Greenness assessment yielded four green quadrants according to the National Environmental Methods Index (NEMI), an Eco-Scale Analytical (ESA) score of 86, and an Analytical Greenness Metric (AGREE) score of 0.74. The Blue Applicability Grade Index score of 75 further supported the method’s practical applicability. The proposed method provides a reliable, green, and practical alternative for the routine quality control of tinidazole tablets.