Eco-friendly chromatographic methods for concurrent estimation of Montelukast and Bambuterol with its pharmacopoeial related substance Terbutaline: Greenness appraisal using analytical Eco-scale, GAPI and AGREE metrics

Abstract

This study represents the development of new eco-friendly HPLC and HPTLC methods for simultaneous quantification of montelukast sodium (MLK), bambuterol hydrochloride (BAM) and terbutaline (TER) as the pharmacopeial related substance of BAM. The HPLC-DAD procedure employed Zorbax eclipse plus C8 column (4.6 × 250 mm, 5 µm particle size) as a stationary phase and a mobile phase consisting of a mixture of 0.003 M phosphate buffer pH 5.0 and acetonitrile eluted in a gradient mode at a constant flow rate of 1.1 mL/min. The chromatograms were recorded at 210 nm for the three analytes. The HPTLC employed precoated HPTLC silica gel aluminum plates 60 F254 as stationary phase with a mobile phase system consisting of ethyl acetate, ethanol and ammonia (78.9: 12: 9.1). The developed plates were scanned densitometrically at 210 nm for the three analytes. Analytical performance of the adopted methods was validated according to the ICH guidelines with respect to linearity, ranges, detection and quantification limits, precision, accuracy, specificity and robustness. The adopted methods were successfully applied for the concurrent analysis of MLK and BAM in their combined tablets. Finally, greenness assessment using various approaches; analytical Eco-Scale, green analytical procedure index (GAPI) and the more recent Analytical GREEnness metric (AGREE) was performed to confirm the greenness of the proposed HPLC and HPTLC methods and to compare them with previously published chromatographic methods.