Eco-friendly chromatographic techniques for appraisal of Amlodipine, Hydrochlorothiazide, Telmisartan, and their related substances in dosage form: Application to six sigma and content uniformity approaches

Background: The present study investigates seven greenness assessment tools to evaluate the greenness of validated novel chromatographic methods used to assess Amlodipine (AML), Hydrochlorothiazide (HYD), Telmisartan (TEL), and their related substances in solid formulations under various stress conditions. Objective: The fundamental goal of green analytical chemistry (GAC) is to substitute hazardous materials or waste production with environmentally friendly alternatives. Method: The mobile phase used in the first RP-HPLC system was a gradient program from solution (A) phosphate buffer pH 3.0 and solution (B) acetonitrile with 50 μL injection volume and a flow rate of 1.0 mL/min, whereas the gradient mobile phase used in the second method was composed of solution (A) phosphate buffer pH 3.0 and solution (B), which is made from acetonitrile: methanol (50:50) with 30 μL injection volume, and flow rate of 1.5 mL/min. It has been found that Thermo Hypersil C18 (25 × 0.46 cm, 5 m) and ACE C8 (15 × 0.46 cm, 5 m) analytical columns are the best stationary phases for the first and second RP-HPLC methods, respectively. Results: The statistical data of calibration curves for AML, HYD, and TEL highly indicate linearity with a correlation value greater than 0.999 and acceptable recovery results between 99 and 100 %. Content uniformity testing on finished products revealed that they met the acceptance standards at 85–115 percent of the declared claim. The green metrics were employed to assess the proposed method, yielding an eco-score of 83, analytical method greenness score of 306.23, analytical method volume intensity score of 90, AGREE score of 0.69, AGREEprep score of 0.59, GAPI resulting in seven green, six yellow, and two red indicators, and ComplexGAPI yielding a fifteen green, eight yellow, and two red signifying a considerable degree of environmental sustainability. Conclusion: Our study was comprehensively assessed according to ICH requirements. The estimated analytical techniques can separate the active drug from its degradation products.