Innovative Integration of Charge-Transfer Reaction and Response Surface Methodology for the Development of a Green Microwell Spectrophotometric Method with High Throughput for the Quantitation of Sitagliptin: Applications to Tablet Content and Unifor
Reem M. Abuhejail, Nada S. Al-Theyab, Hadeel A. Alghobin, Nourah Z. Alzoman, Ibrahim A. DarwishIntroduction:
Sitagliptin (SIT) is a widely used oral antihyperglycaemic agent. While diverse analytical methods have emerged for its quantification, most of these methods lack green chemistry principles and suffer from limited throughput, highlighting the need for more sustainable approaches.
Methods:
In the present study, the aim was to develop and validate a green and efficient method for microwell spectrophotometry (MW-SPM) to quantify SIT in marketed tablet formulations. The MWSPM employs a novel, eco-friendly, and microscale single-step process to generate a colored chargetransfer complex (CTC) by reacting SIT with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The absorbance of the CTCs was measured by a microplate reader. The reaction conditions were optimized, and measurement accuracy was refined using UV-visible spectrophotometry, computational modeling, and response surface methodology (RSM).
Results:
The MW-SPM produced a stable 1:1 CTC complex with SIT, showing linearity in the range of 2-100 µg/well and a limit of quantification of 4.1 µg/well. This method effectively quantified SIT in tablet formulations, ensuring content uniformity. Based on computational modeling, the interactive site on SIT was identified, clarifying the reaction mechanism and the interaction dynamics with DDQ. The greenness of the MW-SPM was verified using GAPI and AGREE metrics.
Discussion:
A green, high-throughput MW-SPM was developed for Sitagliptin analysis using DDQ, and optimized via RSM for precision, sensitivity, and selectivity. The method outperforms traditional UV and HPLC techniques in efficiency, sustainability, and in practical tablet analysis.
Conclusion:
The MW-SPM provides a novel, high-throughput, cost-effective, and eco-friendly method for SIT quantification. Its procedural simplicity, sustainable design, and superior throughput offer significant advancements over existing spectrophotometric techniques, aligning with green analytical chemistry principles.