QUANTITATIVE SIMULTANEOUS DETERMINATION OF AMLODIPINE, VALSARTAN, AND HYDROCHLOROTHIAZIDE IN “EXFORGE HCT” TABLETS USING HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY AND HIGH-PERFORMANCE THIN-LAYER CHROMATOGRAPHY

Sustainable chromatographic quantitation of multi-antihypertensive medications: application on diverse combinations containing hydrochlorothiazide along with LC-MS/MS profiling of potential impurities: greenness and whiteness evaluation

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.

High performance liquid chromatographic assay of amlodipine, valsartan and hydrochlorothiazide simultaneously and its application to pharmaceuticals, urine and plasma analysis

A Simple, Specific, Precise, Accurate, Linear, Rugged, Robust High Performance Liquid Chromatographic method of analysis for simultaneous determination of assay of Amlodipine, Valsartan and Hydrochlorothiazide drugs in the pharmaceuticals tablet formulations using Pioglitazone as a common internal standard was developed and validated. The assay was accomplished using a mixture of acetonitrile & methanol in the volume ratio of 20:80 v/v (mobile phase B) and Ammonium acetate buffer (Mobile phase A) in gradient flow as mobile phase on an Hibar RP-18e, 250 × 4.6 mm, 5µ as chromatographic column at a flow rate of 1.300 mLmin-1, injection volume 10 µL and at a wavelength 235 nm with UV detector. Linearity of the analytical method was evaluated at a concentration range of 2.5-45.3 µg/ml for Amlodipine, 32.0-720.1 µg/ml for valsartan and 5.0-112.6 µg/ml for Hydrochlorothiazide respectively with Correlation coefficient (r) value more than 0.9997. The limit of detection (LOD) for Amlodipine, Valsartan and Hydrochlorothiazide was found to be 1.1 µg/ml, 8.0 µg/ml & 1.0 µg/ml respectively. Specificity, Method Precision, System Precision, Ruggedness, Robustness, Recovery, Stability of analytical solution, Filter paper selection study, Stress testing (Force Degradation) at various conditions were performed as per the ICH (Q2) recommendations. The chromatographic method may also be applied for simultaneous estimation of analytes in plasma and urine.

High performance thin-layer and high performance liquid chromatography coupled with photodiode array and fluorescence detectors for analysis of valsartan and sacubitril in their supramolecular complex with quantitation of sacubitril-related substance in raw material and tablets

Valsartan (VAL) and sacubitril (SAC) are combined in a supramolecular complex, LCZ696, which is a newly approved remedy for heart failure. SAC-related substance (biphenyl methyl pyrrolidinone [BMP]) which also appears as an intermediate during SAC synthesis is considered to be a suspected impurity for SAC and/or LCZ696 tablets. The study investigates the analysis of VAL and SAC in their supramolecular complex along with SAC-related substance, BMP, using high performance thin-layer chromatography (HPTLC) and high performance liquid chromatography (HPLC) with two different detectors; fluorescence detector (FLD) and diode array detector (DAD). The work aimed at analyzing BMP at low levels in the presence of its parent drug, SAC. BMP was successfully analyzed at a level of 0.167, 1 and 3% of its parent drug, SAC upon using HPLC-FLD, HPLC-DAD and HPTLC, respectively. For HPLC-FLD, the detector was set at λex/λem (nm/nm): 0-4.5 min at 255/374; 4.5-6 min at 255/314, for achieving an adequate sensitivity of the method to monitor and quantify VAL and SAC in the presence of BMP. Low limits of detection (8.3, 3.3 and 1.7 ng mL-1) and limits of quantitation (25, 10 and 5 ng mL-1) values obtained for VAL, SAC and BMP, respectively, upon using FLD suggest that low level of baseline noise enables the detection and quantitation of low BMP concentration.

Comparative study between derivative spectrophotometry and multivariate calibration as analytical tools applied for the simultaneous quantitation of Amlodipine, Valsartan and Hydrochlorothiazide

Four simple, accurate and specific methods were developed and validated for the simultaneous estimation of Amlodipine (AML), Valsartan (VAL) and Hydrochlorothiazide (HCT) in commercial tablets. The derivative spectrophotometric methods include Derivative Ratio Zero Crossing (DRZC) and Double Divisor Ratio Spectra-Derivative Spectrophotometry (DDRS-DS) methods, while the multivariate calibrations used are Principal Component Regression (PCR) and Partial Least Squares (PLSs). The proposed methods were applied successfully in the determination of the drugs in laboratory-prepared mixtures and in commercial pharmaceutical preparations. The validity of the proposed methods was assessed using the standard addition technique. The linearity of the proposed methods is investigated in the range of 2-32, 4-44 and 2-20 μg/mL for AML, VAL and HCT, respectively.