Abstract
Cardiovascular disorders are among the leading causes of death worldwide, especially hypertension, a silent killer syndrome requiring multiple drug therapy for appropriate management. Hydrochlorothiazide is an extensively utilized thiazide diuretic that combines with several antihypertensive drugs for effective treatment of hypertension. In this study, sustainable, innovative and accurate high performance liquid chromatographic methods with diode array and tandem mass detectors (HPLC-DAD and LC-MS/MS) were developed, optimized and validated for the concurrent determination of Hydrochlorothiazide (HCT) along with five antihypertensive drugs, namely; Valsartan (VAL), Amlodipine besylate (AML), Atenolol (ATN), Amiloride hydrochloride (AMI), and Candesartan cilextil (CAN) in their diverse pharmaceutical dosage forms and in the presence of Chlorothiazide (CT) and Salamide (DSA) as HCT officially identified impurities. The HPLC-DAD separation was achieved utilizing Inertsil ODS-3 C18 column (250 × 4.6 mm, 5 μm) attached with photodiode array detection at 225.0 nm. Gradient elution was performed utilizing a mixture of solvent A (20.0 mM potassium dihydrogen phosphate, pH 3.0 ± 0.2, adjusted with phosphoric acid) and solvent B (acetonitrile) at ambient temperature. Linearity ranges were 0.1-100.0 µg/mL for HCT, VAL, AML and CAN, 0.05 -100.0 µg/mL for both ATN and AMI and 0.05-8.0 µg/mL for both CT and DSA. Additionally, this work describes the use of liquid chromatography-electrospray-tandem mass spectrometry for the accurate detection and quantification of the impurities; CT and DSA in the negative mode utilizing triple quadrupole mass spectrometry. The linearity ranges for those impurities were 1.0-200.0 ng/mL and 5.0-200.0 ng/mL for CT and DSA, respectively. Developed methods' validation was achieved in accordance with International Conference on Harmonization (ICH) guidelines. Upon applying liquid chromatographic techniques for the drug analysis, a green and sustainable assessment have to be handled due to the consumption of energy and many solvents. Through the use of the HEXAGON, Analytical Greenness (AGREE) and White Analytical Chemistry (WAC) tools, greenness and sustainability have been statistically assessed. The optimized HPLC-DAD and LC-MS/MS methods were fast, accurate, precise, and sensitive, and consequently could be applied for conventional analysis and quality control of the proposed drugs in their miscellaneous dosage forms for the purpose of reducing laboratory wastes, time of the analysis time, effort, and cost.