Anormal Thermal History Effect on the Structural Dynamics of Probucol Infiltrated into Porous Alumina
| Autor: | Kamil Kaminski, Karolina Jurkiewicz, Agnieszka Talik, Joanna Grelska, Marian Paluch, Ewa Kamińska, Aldona Minecka, Magdalena Tarnacka, Barbara Hachuła |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Diffraction
anodic aluminum oxide (AAO) Materials science differential scanning calorimetry (DSC) History effect Probucol Analytical chemistry probucol (PRO) 02 engineering and technology Dielectric 010402 general chemistry X-ray diffraction (XRD) 01 natural sciences Differential scanning calorimetry Thermal medicine Physical and Theoretical Chemistry Fourier transform infrared spectroscopy Porosity broadband dielectric (BDS) infrared spectroscopy (FTIR) 021001 nanoscience & nanotechnology 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials General Energy 0210 nano-technology medicine.drug |
| Zdroj: | The Journal of Physical Chemistry C. 125:3901-3912 |
| ISSN: | 1932-7455 1932-7447 |
| Popis: | Herein, broadband dielectric (BDS) and Fourier transform infrared spectroscopy (FTIR), together with differential scanning calorimetry (DSC) and X-ray diffraction (XRD), were applied to study the molecular dynamics, molecular interactions as well as physical stability of an amorphous Active Pharmaceutical Ingredient (API)-probucol (PRO)-infiltrated into anodic aluminum oxide (AAO) membranes of pore size, d ~ 10-160 nm. Interestingly, the behavior of examined substance strongly depends on the applied thermal protocol. Remarkably, for the first time, we observed that the structural dynamics of the slowly cooled PRO under confinement is significantly enhanced when compared to thatofthe quenched material. This unusual behavior was interpreted as a result of surface-induced effects (including the formation of well-resolved interfacial H-bonded layer and adsorption-desorption processes near the interface) that are magnified by the extremely high sensitivity to density fluctuation of studied PRO, reflected in the enormous pressure coefficient of the glass transition temperature dTg/dp = 427 K/GPa. In fact, FTIR investigations revealed that PRO tends to self-associate under confinement and forms a strongly bonded interfacial layer, which controls the variation in the structural dynamics of core molecules. Finally, we observed that the tendency to crystallize of confined API is reduced with respect to the bulk, even though the critical size of PRO nuclei (rc ~ 3 nm) is significantly lower than the smallest examined pore size. Nevertheless, after few weeks of storage, the investigated substance crystallized in larger pores, while it remained stable in the nanochannels of d = 10 nm. A combination of XRD and DSC measurements indicated that the infiltrated PRO forms two polymorphs, the stable form I (dominating in bulk) and unstable form II (prevailing under confinement). That means that porous matrices might be used to obtain and maintain prolonged stability of unstable polymorphic forms of API. |
| Databáze: | OpenAIRE |
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