Unexpected Factors Affecting the Kinetics of Guest Molecule Release from Investigation of Binary Chemical Systems Trapped in a Single Void of Mesoporous Silica Particles

Abstract

In this work, we present results for loading of well-defined binary systems (cocrystal, solid solution) and untreated materials (physical mixtures) into the voids of MCM-41 mesoporous silica particles employing three different filling methods. The applied techniques belong to the group of "wet methods" (diffusion supported loading -DiSupLo) and "solvent-free methods" (mechanical ball-mill loading -MeLo, thermal solvent free -TSF). As probes for testing the guest1-guest2 interactions inside the MCM-41 pores we employed the benzoic acid (BA), perfluorobenzoic acid (PFBA), and 4-fluorobenzoic acid (4-FBA).The guests intermolecular contacts and phase changes were monitored employing magic angle spinning (MAS) NMR Spectroscopy techniques and powder X-ray diffraction (PXRD). Since mesoporous silica materials are commonly used in drug delivery system research, special attention has been paid to factors affecting guest release kinetics. It has been proven that not only the content and composition of binary systems, but also the loading technique have a strong impact on the rate of guests release. Innovative methods of visualizing differences in release kinetics are presented.

A New Look at the Mechanism of Cocrystal Formation and Coformers Exchange in Processes Forced by Mechanical and/or Thermal Stimuli – ex situ and in situ Studies of Low‐Melting Eutectic Mixtures

“…Similar effect was observed by Trzeciak et al . when the mechanism of loading binary systems into MCM‐41 mesoporous silica was investigated [47] . The values of centrifugal pressure depend on the size of a rotor and a spinning rate (see ESI, Figure S1a) [48] .…”

“…[46] Similar effect was observed by Trzeciak et al when the mechanism of loading binary systems into MCM-41 mesoporous silica was investigated. [47] The values of centrifugal pressure depend on the size of a rotor and a spinning rate (see ESI, Figure S1a). [48] It has to be stressed that another effect which is also related with a sample spinning is a change of temperature inside the rotors (T MAS ).…”

Drug-Coformer Loaded-Mesoporous Silica Nanoparticles: A Review of the Preparation, Characterization, and Mechanism of Drug Release

“… 66 Meanwhile, a cocrystal of BA-4-FBA was formed within MPS after being prepared by the DiSupLo method. 65 …”

“…Solid-state NMR studies clarified that the interaction mode between the BA and 4-FBA was similar to cocrystal, indicating the formation of BA −4-FBA within MPS. 65 …”

“…Solid-state NMR studies clarified that the interaction mode between the BA and 4-FBA was similar to cocrystal, indicating the formation of BA −4-FBA within MPS. 65 Characterization of Drug-Coformer Loaded MPS Nitrogen Adsorption/Desorption Analysis Physical gas sorption is a well-established method used to characterize the textural properties of solid surfaces and changes after various actions. This method can precisely determine the amount of gas adsorbed on the surface material measuring the porous properties and structure.…”