Simple and Novel Fluorimetric Protocol for Sitagliptin Estimation Through Sensitivity Enhancement Using Acetic Acid: Application to Pharmaceutical Dosage Form With Green Assessment

A simple, cost-effective, reproducible, highly sensitive, and green spectrofluorimetric technique for sitagliptin phosphate estimation has been established in its pure form and commercial formulation. The native fluorescence of sitagliptin was enhanced by inhibiting photoinduced electron transfer through optimization of medium pH. The highest fluorescence intensity of sitagliptin was observed at 296 and 583 nm after excitation at 265 nm, using 0.50-M acetic acid. The method exhibited a wide linearity range (0.30-4.00 μg/mL) with high correlation coefficient values of 0.9998 at both 296 and 583 nm, limits of detection of 0.09 and 0.10 μg/mL, and the limits of quantitation of 0.27 and 0.29 μg/mL, respectively. The guidelines of ICH have been applied for validation of the proposed method. The obtained results have been compared with the previous reported methods. The developed fluorimetric protocol demonstrated high accuracy and excellent precision for estimation of sitagliptin in commercial tablets. Furthermore, the method was confirmed to be environmentally friendly using AGREE, GAPI, Analytical Eco-Scale, MA, and AGSA tools. As a conclusion, the proposed fluorimetric protocol is highly suitable for the quality control of sitagliptin phosphate.