Simple cloud point microextraction based on indophenol dye formation for mesalazine determination in pharmaceutical and biological samples

Abstract
An efficient, sensitive, and environmentally friendly technique for determining mesalazine concentrations in pure drug dosage forms and blood serum using room temperature cloud point microextraction (RT-MCPE) is proposed in this study. The procedure relies on the formation of a blue indophenol dye in an alkaline medium that occurs due to an oxidative coupling reaction between mesalazine and syringic acid. The resultant dye can shift from blue to pink by forming an ion-pair complex with the acetate buffer (pH 3) used. To separate the dye from the surrounding aqueous environment, sodium sulfate (Na2SO4) and a nonionic surfactant, Triton X-114, were added to the solution, allowing the dye molecules to form micelles around the surfactant at room temperature. After using NaOH to restore the blue colour of indophenol, the solution was diluted and its absorbance at 635 nm was measured using a visible spectrophotometer, with all the experimental parameters optimised. The calibration curve exhibited linearity in the range of 0.25–10 μg mL−1 mesalazine, with a limit of detection of 0.04 μg mL−1. The method allowed for the accurate determination of the mesalazine content in drug dosage forms and serum, with an average recovery rate of 99.2% and a preconcentration factor of approximately 20. It yielded comparable results to traditional HPLC measurements, suggesting that it can serve as a reliable alternative or supplementary method for mesalazine determination.

Author
Diyar Salahuddin Ali

DOI
https://doi.org/10.1016/j.microc.2023.108862

Publisher
Microchemical Journal

ISSN
1095-9149

Publish Date: