Eco-friendly and Stability-Indicating RP-HPLC method for simultaneous estimation of Fluconazole and Tinidazole in combined dosage form

A stability-indicating RP-HPLC method has been developed and validated for the simultaneous estimation of Fluconazole, its associated organic impurities and Tinidazole in a combined dosage form by implementing isocratic reverse-phase high-performance liquid chromatography (RP-HPLC). These combined dosage forms were simultaneously estimated and related impurities were summarized using an RP-HPLC system with water: Isopropyl alcohol (IPA) (80:20) as the eluting solvent. The stationary phase of Zorbax SB C8 column (150 mm × 4.6 mm, 3.5 μm) was utilized for elution. The method reveals prominent RT of Fluconazole, its related impurities A, B, or C and Tinidazole were found at 3.0, 2.5, 2.8, 6.8 and 2.2 min correspondingly. Validation and impurity profiling parameters were done with adherence to the International Conference on Harmonization (ICH) and United States Pharmacopeia (USP). For both Fluconazole and Tinidazole, detector response has been confirmed to be linear with concentration in the 22.5–135 µg/mL range. The LOD and LOQ for Fluconazole have been 0.054 µg/ml, 0.163 µg/ml and for Tinidazole have been 0.127 µg/ml, and 0.387 µg/ml respectively. The % recovery of 99.5 % and 100.9 % was achieved for Fluconazole and Tinidazole through the assay method with compliance with % RSD of 0.23 % and 0.14 % for six preparations. The forced degradation studies show that Fluconazole and Tinidazole showed well-resolved peaks derived from the drug active ingredient. Finally, the developed method was found to be simple, precise, accurate, and eco-friendly as assessed by greenness using three factors. The developed method is simple, reliable, and prominent for regular adoption of quality control analysis.