Smartphone-Based Colorimetric Determination of Imeglimin Hydrochloride Using Eosin Y: A Simple and Eco-Friendly...

A simple, rapid and eco-friendly smartphone-assisted colorimetric method was developed for the determination of imeglimin hydrochloride (IMG) in pharmaceutical dosage forms. The method is based on the formation of an orange-coloured ion-pair complex between eosin Y (EY) and the amine group of IMG through electrostatic interactions in an acidic medium. The intensity of the resulting colour was quantified using a smartphone camera, and the colour parameters were analysed using ImageJ software and the colour detector application. The absorbance of the resulting IMG-EY complex was recorded spectrophotometrically at the maximum wavelength of 524 nm. The smartphone and spectrophotometric approaches exhibited a linear response in the concentration range of 0.8-10 µg/mL, showing satisfactory accuracy and precision. Furthermore, the analytical performance of the ImageJ and RGB colour detector applications was evaluated and compared, confirming their reliability for quantitative colour analysis. The proposed methods were statistically compared with a direct spectrophotometric method for IMG determination. The combination of smartphone-based analysis with colorimetric detection provides a cost-effective, portable and user-friendly alternative for the routine quality control of pharmaceutical formulations.