Manipulating the physical states of confined ibuprofen in SBA-15 based drug delivery systems obtained by solid-state loading: Impact of the loading degree

Abstract

Using the Milling-Assisted Loading (MAL) solid-state method, for loading a poorly water-soluble drug (ibuprofen, IBP) within SBA-15 matrix has given the opportunity to manipulate the physical state of drugs for optimizing bioavailability.MAL method makes it easy to control and analyze the influence of the degree of loading on the physical state of IBP inside SBA-15 matrix with an average pore diameter of 9.4 nm. It was found that the density of IBP molecules in an average pore size has a direct influence both on the glass transition and the mechanism of crystallization. Detailed analyzes of the crystallite distribution and melting by Raman

Structure of Water at Hydrophilic and Hydrophobic Interfaces: Raman Spectroscopy of Water Confined in Periodic Mesoporous (Organo)Silicas

“…19,37 The Raman signal of the silica matrix was negligible compared to the signal of the confined water, as already observed for other molecules confined in the SBA-15 matrix. 38,39 This is in contrast to ref 40 that reported prominent contributions from laser radiation-induced defects. Spectra of bulk water and confined water exhibit qualitatively the same shape, composed of a broad triple hump extending over this selected spectral region.…”

“…Raman spectra of bulk water and water-filled MCM-41 recorded at 20 °C are presented in Figure . Special attention was paid to the O–H stretching region (2800–4000 cm –1 ) to probe the molecular structure , and the intermolecular H-bonds. , The Raman signal of the silica matrix was negligible compared to the signal of the confined water, as already observed for other molecules confined in the SBA-15 matrix. , This is in contrast to ref that reported prominent contributions from laser radiation-induced defects. Spectra of bulk water and confined water exhibit qualitatively the same shape, composed of a broad triple hump extending over this selected spectral region.…”

Influence of Pore Surface Chemistry on the Rotational Dynamics of Nanoconfined Water

“…From a fundamental point of view, confining water at the nanoscale in prototypical porous solids has turned out to be particularly adequate in order to better understand the unusual behavior of interfacial water. For pore diameter d < 2.5 nm, crystallization of confined water is suppressed by inhibition of the nucleation process, , which was considered as an opportunity to study anomalous physical properties of liquid water in a wide temperature range. , Among several types of confinement, including clay, graphite oxide, zeolite, or porous silica glasses, , the mesostructured SBA-15 and MCM-41 are particularly suited hosts due to their well-defined porous geometry formed by ordered cylindrical channels. , Dynamics of confined supercooled water in MCM-41 has been studied with various experimental techniques such as dielectric relaxation spectroscopy (DRS), nuclear magnetic resonance (NMR), and quasi-elastic neutron scattering (QENS) …”

Is it possible to predict the stability of a crystal structure under the influence of pressure? Quantum chemical study of ibuprofen crystals

“…42 Amorphous ibuprofen was synthesized in two ways: through the melting ( T melt = 349 K) and the subsequent quenching of the mass below the glass transition temperature ( T glass = 228 K) 43 and through co-grinding with mesoporous silica carriers at room temperature. 44,50 If the drug is heated further, amorphous ibuprofen undergoes recrystallization. It can pass to form I or II depending on the heating speed and final temperature of the system.…”