Page 1 of 33 Response surface methodology for spectrophotometric determination of two β-adrenergic agonists-terbium chemosensors in urine and pharmaceutical dosage forms Marwa Sakr a , Marwa Fouad b,* , Rasha Hanafi c , Hala Al-Easa a , Samir El-Moghazy b a Department of Chemistry and Earth Sciences, College of Arts and Sciences, Qatar University, Doha 2713, Qatar b Pharmaceutical Chemistry Department, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt c Department of Pharmaceutical Chemistry, Faculty of Pharmacy and Biotechnology, German University in Cairo, Egypt *Corresponding author Marwa Fouad Marwa.fouad@pharma.cu.edu.eg Abstract Background: According to literature reports, none of the previous methods of analysis had touched the multivariate approach for the quantification of significant factors affecting the interaction of dobutamine or hexoprenaline with Terbium. Objective: Two novel β-adrenergic agonists-lanthanide chemosensors were prepared for the determination of Dobutamine and Hexoprenaline in their pure and pharmaceutical dosage forms and in urine samples. Fabrication of the two chemosensors was based on their ligand-metal interaction with the lanthanide Terbium. Methods: A Plackett-Burman design was selected for the screening of four main variables (reaction time, metal volume, pH and temperature). Applying Response Surface Methodology, a Central Composite design was executed for the optimization of the significant factors with narrower upper and lower limits. Spectrophotometric technique was exploited for the analysis of the two chemosensors. Results: Maximum absorption was obtained at 299 nm and 298 nm for dobutamine-terbium and hexoprenaline-terbium complexes, respectively. Only factors that were found to bear significant effects on the formed complexes were promoted to the optimization level. Model verification was carried out, where target results coincided with those at the predicted levels, indicating the efficiency of the two proposed models. Validation of the proposed was implemented and linear ranges were found to be 3.30-13.50 µg/mL and 1.90-10.00 µg/mL, for dobutamine and hexoprenaline, respectively. Conclusion: Recovery and relative standard deviation values by application in pure powder, pharmaceutical dosage forms and © AOAC INTERNATIONAL 2020. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com Downloaded from https://academic.oup.com/jaoac/advance-article/doi/10.1093/jaoacint/qsaa131/5911623 by guest on 26 September 2020