Determination of Sitagliptin with Fluorescamine in Tablets and Spiked Serum Samples by Spectrofluorimetry and a Degradation Study

Abstract

Two novel, simple and rapid stability-indicating spectrofluorimetric methods have been developed for the determination of sitagliptin in tablets and spiked serum samples. In the first method, sitagliptin`s natural fluorescence was measured at 353 nm after excitation at 259 nm. On the basis of the reaction between sitagliptin and fluorescamine the second method has been developed in borate buffer solution of pH 9.0 and the fluorescence intensities of the derivatives were measured at 475 nm emission and 390 nm excitation wavelengths. Thecalibration curves were constructed in concentration range of 0.5-10.0 mu g mL(-1) and 0.2-1.4 mu g mL(-1) for the first and second method, respectively. The developed methods were validated with respect to linearity, precision, sensitivity, accuracy and selectivity. The degradation behaviour of the drug was investigated using the first method. The drug solution was subjected to neutral, acid and alkali hydrolysis, oxidation, thermal stress and exposured to the sunlight. The first method is proved to be selective and useful for the investigation of the stability of sitagliptin. The application of spiked serum samples was also analysed by using the second method. The developed methods were successfully applied for the determination of sitagliptin in tablets and spiked serum samples.