Effect of Food-Grade Pharmaceutical Excipients on Physicochemical Behaviour of Quercetin Nanocomposites: Thermal and Non-Thermal Analysis

In this study, the compatibility of Quercetin (QC) nanocomposites with some selective food-grade pharmaceutical excipients was assessed using various thermal (DSC and TGA), non-thermal (P-XRD, FT-IR, and RAMAN spectroscopy, and FESEM) techniques. All techniques were simultaneously used and correlated to detect the QC’s compatibility with the selected excipients (CO, CCO, OA, T20, T60, and T80). DSC-TG studies showed that QC-CO and QC-T60 samples exhibited irregular degradation patterns, causing the drug’s transformation from crystalline to amorphous. P-XRD results showed that the crystalline behavior of QC was retained in all the samples. However, the peak intensities were reduced and shifted in some samples. The D_avg. value for all samples, including pure QC, was 26.80-76.07 nm. FT-IR and RAMAN studies demonstrated that bonds including –C=O stretching, C-C stretching (ring A), and-OH bonds (in ring A, B, and C) in pure QC play a crucial role in its interaction with excipients. Furthermore, the excipients’ effect on QC’s morphology using FESEM showed smoothening, fragmentation, and agglomeration of the drug. In conclusion, the possible drug-excipient incompatibility can be potentially determined with the help of these analytical meth-ods. The physicochemical studies from this work may provide immense knowledge for the researchers and manufacturers involved in quercetin-based pharmaceutical and/or nutraceutical formulations.