Diarylpyrrolone based fluorophore for the selective spectrofluorometric method for determination of Linagliptin antidiabetic drug in pharmaceutical tablets

Linagliptin (LNG) is a type 2 antidiabetic drug which belongs to dipeptidyl peptidase 4 inhibitors. In this paper a simple and sensitive spectrofluorometric method was developed and validated for the determination of LNG. The method employed the interaction of the primary amino group of the cited drug with fluorescamine reagent in aqueous borate buffer (pH 8.5) to produce a highly fluorescent product. The emission of the formed product was measured at 479 nm after excitation at 390 nm. Different experimental parameters that may affect the product formation or its fluorescence intensity were investigated and adjusted. The method has a good linearity in the concentration range of 0.2 – 2.0 μg mL−1of LNG with a detection limit of 0.079 μg mL−1.The performance of the developed method was evaluated according to the International Conference for Harmonization (ICH). The method was successfully applied for the analysis of tablets dosage form that contained the cited drug. The results of the analysis were compared with the reported method and indicated good accuracy and precision of the proposed procedure.