Sustainable green spectrophotometric determination of bisoprolol and amlodipine via diazotization–coupling approach in pharmaceutical and biological matrices
Year: 2026
Type: article
Abstract: Objective This study aimed to develop a sustainable, sensitive, and cost-effective spectrophotometric method for the individual quantification of bisoprolol (BIS) and amlodipine (AML) in pharmaceutical dosage forms and spiked human urine samples. Proposed method The method is based on the diazotization of anthranilic acid followed by an azo-coupling reaction with each drug in an ethanol–water medium (50/50 v /v), forming stable red chromophores. Key experimental parameters including reagent volumes, pH, reaction time, and temperature were systematically optimized to maximize color intensity and reproducibility. Absorbance measurements were performed at 545.5 nm for BIS and 550 nm for AML. The greenness of the method was comprehensively evaluated using AGREE, GAPI, and Analytical Eco-Scale metrics. Results The method exhibited excellent linearity over the concentration range of 1–16 μg mL −1 for both drugs, with correlation coefficients exceeding 0.998. The limits of detection were 0.480 μg mL −1 for BIS and 0.321 μg mL −1 for AML, while the limits of quantification were 1.467 and 1.225 μg mL −1 , respectively. Accuracy was satisfactory with recoveries ranging from 99.5% to 101.5%, and precision was confirmed by relative standard deviations (RSD) between 0.76% and 1.7%. The method achieved an AGREE score of 0.78 and an Eco-Score of 85, confirming excellent environmental sustainability. Successful application was demonstrated on commercial tablets (Concor® 2.5 mg and Norvasc® 5 mg) and 5% spiked human urine samples with no significant interference from common excipients .
Source: Results in Chemistry
Institution: Mustansiriyah University
Language: English
Subfield: Analytical Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,870
OpenAlex ID: W7155569472