Micelle‐enhanced spectrofluorimetric method for determination of sitagliptin and identification of potential alkaline degradation products using LC‐MS

Abstract

A novel, quick, simple and highly sensitive spectrofluorimetric method was developed and validated for the determination of sitagliptin (SG) in its pharmaceutical formulations. The proposed method is based on investigation of the fluorescence spectral behavior of sitagliptin in an SDS micellar system. In an aqueous solution of phosphate buffer pH 4.0, the fluorescence intensity of SG in the presence of SDS was greatly enhanced, by 200%, i.e. twofold enhancement. The fluorescence intensity of SG was measured at 300 nm after excitation at 270 nm. The method showed good linearity in the range 0.03-10.0 µg/mL with a good correlation coefficient (r = 0.9998). The limits of detection and quantitation values were 5.31 and 16.1 ng/mL, respectively. The proposed method was successfully applied to the analysis of SG in its single and co-formulated commercial tablets; the results were in good agreement with those obtained using a reference method. Application of the proposed method was extended to stability studies of SG after exposure to different forced degradation conditions according to the ICH guidelines, such as acidic, alkaline, thermal, photo- and oxidative stress. The chemical structure of certain potential degradation products (DPs) were investigated using LC-MS.

Liquid Chromatography/Electrospray Ionisation Tandem Mass Spectrometric Study of Sitagliptin and its Stressed Degradation Products

“…Sonune et al [ 7 ] developed a stability indicating HPLC method, isolated and characterised degradation products of sitagliptin. Recently Salim et al [ 8 ] developed fl uorescence spectral behaviour of sitagliptin, however, all the structures of the degradation products and plausible mechanistic paths were not delineated yet. This work describes the application of electrospray ionisation tandem mass spectrometry in the identifi cation and structural characterisation of the major degradation products of SIT.…”

Spectrophotometric and Spectrofluorimetric Studies on Azilsartan Medoxomil and Chlorthalidone to Be Utilized in Their Determination in Pharmaceuticals

“…Micelles or reversed micelles are able to stabilize the exited singlet state and delay the decay process, and thus may enhance the intensity of the emission bands. 17 PBS of pH 7.5 was used through this study to allow proper ionization of both analytes. None of the examined surfactants showed significant enhancement in RFI of AZL and CLT (Fig.…”

“…LOQ and LOD were calculated according to ICH recommendations. 17 LOD was considered as the minimum concentration with a signal to noise ratio of at least 3 ( S/N ∼3), whereas LOQ was taken as a minimum concentration with a signal to noise ratio of at least 10 ( S/N ∼10). Results are given in Table 1.…”

Applications of micelle enhancement in luminescence‐based analysis

“…A novel highly sensitive spectrofluorimetric method was also developed and validated for the determination of sitagliptin in its pharmaceutical formulations. The proposed method was based on an investigation of the fluorescence spectral behavior of sitagliptin in an SDS micellar system .…”