Background: Sitagliptin (SITA), is an oral anti-diabetic drug of dipeptidyl peptidase-4 (DPP-4)
inhibitor class used as a monotherapy or in association with metformin to treat type II Diabetes Mellitus.
Methods: Two new, sensitive and precise spectrofluorimetric methods have been developed for the
determination of SITA in tablets and spiked human urine samples. SITA has a native fluorescence that
was enhanced by 2 folds after addition of β-cyclodextrin (method A). The fluoregenic product was
measured at 296 nm after excitation at 267 nm. In addition, SITA was derivatized by 7-chloro-4-
nitrobenzofurazon (NBD-Cl) to a highly sensitive fluoregenic product was measured at 532 nm after
excitation at 466 nm (method B).
Results: The fluorescence intensities were directly proportional to the concentration over the range
0.35-10 µg mL-1 and 0.1-3 µg mL-1 for method A and B, respectively. The %RSD for inter-day and
intra-day precisions was in a range of 0.16-0.92% and the accuracy results were in the range of 96.3% -
Conclusion: Successful applications of the developed methods, for drug determination in pharmaceutical
tablet and spiked human urine samples, were performed with high accuracy and precision.