Better Colorimetric Reserpine Determination in Tablets with 4- Caboxyl-2,6-dintrobenzene diazonium ion (CDNBD) Utilization

Abstract

Goal: Creating a quick, easy, and enhanced colorimetric technique for reserpine tablet assay
Method: The procedure involves combining the aromatic rings of reserpine with the diazonium ion of 4-carboxyl2,6-dinitrobenzene, which results in the creation of an azo adduct. The assay of reserpine in tablets was
conducted by means of method application and optimization of reaction conditions and validation.
Result: Reserpine and CDNBD bonded easily, and when the experimental conditions were optimized, the reaction
was finished in 10 minutes at room temperature. For the azo adduct that formed, a 1:1 drug to reagent
stoichiometric ratio was found. In relation to the medication, the adduct showed a bathochromic shift, while in
relation to the reagent, it showed a clear hyperchromic shift. 470 nm colorimeters were used for sample analysis.
The tests demonstrated linearity and reproducibility within the 2.25 - 24 μg/mL concentration range. The analysis
of reserpine in tablets was effectively conducted using the novel approach, with results that were comparable to
those of the official (USP) spectrophotometric method (p > 0.05). When compared to the previously published
colorimetric technique for reserpine, this approach offers a significant improvement.
In conclusion, the devised approach is quick and may be used for serpine in-process quality control.
KEYWORDS: diazo coupling, 4-Caboxyl-2,6-dintrobenzene diazonium ion (CDNBD), colorimetric, and serpine