Studying structural and local dynamics in model H-bonded active ingredient - Curcumin in the supercooled and glassy states at various thermodynamic conditions.

Studying structural and local dynamics in model H-bonded active ingredient - Curcumin in the supercooled and glassy states at various thermodynamic conditions. Eur J Pharm Sci. 2019 May 10;: Authors: Minecka A, Kamińska E, Heczko D, Jurkiewicz K, Wolnica K, Dulski M, Hachuła B, Pisarski W, Tarnacka M, Talik A, Kamiński K, Paluch M Abstract Different experimental techniques were applied to study thermal and structural properties, strength of H-bonds, possible keto-enol tautomerism and molecular dynamics at various thermodynamic conditions in the H-bonded active substance, curcumin (CRM). Dielectric measurements revealed dynamical features of examined compound that are uncharacteristic for the associated systems. This includes enormously large pressure coefficient of the glass transition temperature and prominent drop of the fragility with compression. Simultaneously, the shape of α-process slightly broadened at elevated pressures. Infrared investigations demonstrated that this effect is related to the variation in the population of H-bonds. Moreover, we studied the changes in the structural and dynamical properties of the glasses prepared upon cooling of the melt (ordinary glass, OG) and the one obtained after compression of CRM in the liquid phase and decompression at T = 293 K (dense glass, DG). Interestingly, during the aging of the latter sample, a clear shift of the β-relaxation towards higher frequencies was noted. Th...
Source: European Journal of Pharmaceutical Sciences - Category: Drugs & Pharmacology Authors: Tags: Eur J Pharm Sci Source Type: research