ABSTRACT A simple, semi‐automated, and sensitive continuous flow‐injection analysis/merging zones technique (CFIA/MZ) method was developed for the determination of Amlodipine Besylate (ADB) in pure, pharmaceutical formulations and biological samples. The method used Rhodamine blue dye (Rh B) as a reagent. The method is based on the bromination of (ADB) with an excess solution of N‐Bromosuccinimide (NBS) in an acidic medium. The excess NBS is assessed by the assessment of the residual NBS based on its ability to bleach the Rhodamine B dye and measuring the absorbance at 620 nm. The amount of NBS reacted coincides with the drug content. The different experimental parameters influencing the development and stability of the color are precisely studied and optimized. A wide calibration curve was rectilinear within the concentration range (10‐200) µg/mL with a correlation coefficient R 2 = 0.9978. The limit of detection 3.9 µg/mL, and the RSD% was 2.1 and Recovery was 101.47. The proposed procedure was applied successfully for the estimation of (ADB) in pharmaceutical and biological samples, and the results obtained were favorably compared with those given by a reference method of the United States Pharmacopoeia (USP), and there was no significant difference between the obtained results, regarding repeatability and reproducibility at the 95% confidence level.
Awad et al. (Tue,) studied this question.