The use of SDS micelles as additive to increase fluorescence analysis of sitagliptin and saxagliptin derivatives in their tablets and human plasma

Abstract

A simple and highly sensitive spectrofluorimetric method was developed and validated for the determination of sitagliptin phosphate (STP) and saxagliptin (SAX). The proposed method is based on Hantzsch reaction of both drugs through their reaction with acetyl acetone-formaldehyde reagent (AAF) followed by investigation of the fluorescence spectral behavior of the formed fluorescent products in presence of Sodium Dodecyl Sulfate (SDS) micellar system as additive to enhance the obtained flourescence at 483 nm after excitation at 419 nm for both drugs. The fluorescence intensity in the presence of SDS increased by 1.7 and 1.6 folds for STP and SAX, respectively than that of the surfactant free aqueous. The linearity of calibration curve was found at range of 50–700 ng mL−1 and 150–900 ng mL−1 with detection limits of 16.43 and 38.60 ng mL−1 for STP and SAX, respectively. The percent recovery ± standard deviation was found to be 99.87 ± 0.77 and 99.00 ± 0.52 for STP and SAX, respectively. The values of relative standard deviations were below 2% indicating good precision of the developed method. The analysis of the studied drugs in bulk, spiked human plasma, dosage form and content uniformity test was successfully applied with high accuracy.