Development and validation of eco-friendly micellar organic solvent-free HPLC method for the simultaneous determination of some antihypertensive combinations

Abstract

To minimize the environmental impacts of using organic solvent without affecting the chromatographic performance, alternatives had to be utilized to decrease such pollution. Combination of sodium dodecyl sulfate (SDS) with polyoxyethylene-23-lauryl ether (Brij-35) could be incorporated as a green alternative for using organic solvents as mobile phases in HPLC separation systems. In this research, a micellar organic solvent-free HPLC method have be established for determination of five antihypertensive drugs, namely, captopril (CPT), hydrochlorothiazide (HCT), indapamide (IND), valsartan (VAL) and carvedilol (CAR). The most favorable conditions were validated using mobile phase consists of 0.1 mol/L SDS, 0.03 mol/L Brij-35, adjusted at pH 2.8 using ortho-phosphoric acid on symmetry C18 column and detection at 210 nm. The flow rate was sudden increased from 1.2 to 1.5 mL/min after two minutes and the total separation run time was nine minutes. The method was successfully applied to determine four different combinations of the analytes in bulk and their pharmaceutical dosage forms. Method validation was done according to International Conference of Harmonization guidelines. At linearity range of 5–100 µg/mL for CPT, HCT and CAR, 8 – 160 µg/mL for VAL, and 2 – 40 µg/mL for IND, high accuracy results were found. Moreover, the coefficient of the variation of the points of the calibration curve being below 2% indicating precise method. The LLOQ was (4.88 μg/mL) for CPT, (4.89 μg/mL) for HCT and CAR, (7.91 μg/mL) for VAL, and (1.81 μg/mL) for IND. The method’s greenness was determined with the help of an eco-scale scoring method, Green Analytical Procedure Index, and Analytical Greenness Calculator and the proposed method was found to be an excellent green methodology.