A Green Synchronous Fluorescence Analysis Approach for Simultaneous Determination of the Co-formulated Antihypertensives, Bisoprolol, and Amlodipine. Application to Plasma Samples, Market Formulations, Content Uniformity Test, and Greenness Evaluation.

In this study, we present a direct, sensitive, and green spectrofluorimetric approach for simultaneous measurement of bisoprolol fumarate (BSL) and amlodipine besylate (AMD) in their tablets and plasma. This approach measures the synchronized fluorescence intensity of the two drugs at Δλ of 55 nm with λ captured at 265 and 375 nm for BSL and AMD, respectively. The method is linear over the concentration range of 0.1-4.1 μg/mL for BSL and 1.0-9.0 μg/mL for AMD. The limit of detection for BSL and AMD is 0.0168 and 0.1227, and the limit of quantification is 0.0508 and 0.3717 μg/mL, respectively. This technique is effectively used to analyze the two studied drugs in their tablets with high %Recoveries of 100.09% for BSL and 99.67% for AMD and %RSD ≤ 1.54. The proposed technique is verified in compliance with the ICH Q2(R2) criteria. Hence, the suggested spectrofluorimetric approach effectively assesses the content uniformity of their tablets in accordance with the British Pharmacopoeia. Besides, BSL is determined in plasma over the range of 0.1-0.5 μg/mL with high percentage recoveries (98.95%-101.60%) and low %RSD values (1.326). The greenness of the developed method was positively assessed using three distinct green metrics, including AGREE, GAPI, and BAGI.