Development of Colorimetric Method for the Quantitative Analysis of Amlodipine Besylate in Dosage form Using 4- Dimethyleaminobenzaldehyde as Derivatizing Reagent

Abdul Ghani Memon, Ayaz Ali Memon, Faqeer Mahboob Ali Rind Zahid Ali Zounr, Azhar Ali Ayaz Pirzada, Nazir Ahmed Brohi, Mazhar Iqbal Khaskheli and Jamil Rahman Memon Dr. M. A. Kazi Institute of Chemistry, University of Sindh, Jamshoro-76080, Pakistan. National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro-76080, Pakistan. Department of Electronic Engineering, University of Sindh, Jamshoro-76080, Pakistan. Department of Microbiology, University of Sindh, Jamshoro-76080, Pakistan. *Corresponding Author Email: ayazmemon33@gmail.com Received 14 November 2019, Revised 02 May 2020, Accepted 20 June 2020 -------------------------------------------------------------------------------------------------------------------------------------------Abstract The study is based on the determination of amlodipine besylate (AB) after derivatization with 4dimethylaminobenzaldehyde (DMAB) using UV/Visible spectrophotometer at pH 5 to yield derivative that is measured at λ max 399 nm. The calibration graph obtained was liner and fulfilled Beer Lambert’s law in the concentration range 05-25 μg/mL of (AB) and DMAB having coefficient of determination R2 0.9988 with RSD 0.93% and molar absorptivity 4.04x10 mole cm. Quantitative / analytical parameters such as pH, heating time, temperature were optimized. Reagent concentration /volume, interday and intraday studies were also carried out. There was no effect of various solvents and additives observed on the determination of AB in commercially available drugs. The method is stable, accurate, rapid and simple for the study of imine derivative of AB.