Understanding Fenofibrate Release from Bare and Modified Mesoporous Silica Nanoparticles

Abstract

To investigate the impact of the surface functionalization of mesoporous silica nanoparticle (MSN) carriers in the physical state, molecular mobility and the release of Fenofibrate (FNB) MSNs with ordered cylindrical pores were prepared. The surface of the MSNs was modified with either (3-aminopropyl) triethoxysilane (APTES) or trimethoxy(phenyl)silane (TMPS), and the density of the grafted functional groups was quantified via 1H-NMR. The incorporation in the ~3 nm pores of the MSNs promoted FNB amorphization, as evidenced via FTIR, DSC and dielectric analysis, showing no tendency to undergo recrystallization in opposition to the neat drug. Moreover, the onset of the glass transition was slightly shifted to lower temperatures when the drug was loaded in unmodified MSNs, and MSNs modified with APTES composite, while it increased in the case of TMPS-modified MSNs. Dielectric studies have confirmed these changes and allowed researchers to disclose the broad glass transition in multiple relaxations associated with different FNB populations. Moreover, DRS showed relaxation processes in dehydrated composites associated with surface-anchored FNB molecules whose mobility showed a correlation with the observed drug release profiles.

Investigating the Influence of Processing Conditions on Dissolution and Physical Stability of Solid Dispersions with Fenofibrate and Mesoporous Silica

“…However, in some formulations, small peak shifts can be seen for the peak at 2985 cm −1 and 1726 cm −1 to 2969 cm −1 and 1730-1736 cm −1 , respectively (note the dashed lines in the magnified figures within Figure 7). According to Figari et al, shifts towards lower wavenumbers in the spectral region 2900-3000 cm −1 could be due to either amorphization or the build-up of interactions with the silanol groups on the pore walls [38]. The peak shift from 1726 cm −1 to higher wavelengths, together with band broadening, is consistent with changes reported for amorphous FF [32,38].…”

“…All spectra are shown in Figure 7. The peaks that are clearly seen in the spectra of FF are at approximately 2985 cm −1 (C-H stretching of the isopropyl group), 1726 cm −1 and 1649 cm −1 (C=O bonds stretching), 1597 cm −1 and 1588 cm −1 (in-plane benzene ring stretch), 1247 cm −1 and 1146 cm −1 (C-O bonds stretching), and other peaks in the spectral region below 1200 cm −1 [32,37,38]. Syloid shows a strong intensity band at 900-1300 cm −1 , which is characteristic of Si-O stretching [22].…”

Controlled Sublimation Rate of Guest Drug from Polymorphic Forms of a Cyclodextrin-Based Polypseudorotaxane Complex and Its Correlation with Molecular Dynamics as Probed by Solid-State NMR

“…The 13 C and 1 H NMR spectra revealed that the order of SA mobility in the complexes is MC form ≫ HC form > TC form, which coincided with the order of its sublimation. Mobility of a guest compound encapsulated in a host structure such as CD or mesoporous silica can be affected by factors such as cavity size or pore diameter, pore matrix, host/guest interactions, and so on. − Generally, an increase in the cavity or pore size of the host compound has a direct effect on the molecular mobility of the guest compound . However, the mobility of SA could not be correlated to the host intermolecular space size, which is in the order of TC form > MC form ≥ HC form.…”

“…A substantial number of studies have witnessed this. The molecular state and dynamics of the guest API can be affected by various parameters such as cavity size or pore diameter, binding geometry, porous matrix and topology, and host/guest interaction. − Knapik et al revealed that the stability of amorphous ezetimibe incorporated in porous materials with different pore sizes was influenced by its molecular mobility, immobilization effect, and pore size . Dionísio and co-workers investigated the influence of the physical state, molecular mobility, and distribution of naproxen encapsulated in three different hosts (unmodified MCM-41, silylated by methyl capping MCM-41sil, and biphenylene-bridged silica matrix PMOBph) with similar pore size .…”

Enhancing Dendritic Cell Activation Through Manganese-Coated Nanovaccine Targeting the cGAS-STING Pathway

“…7 Hence, current research is directed towards pH-responsive, photo-sensitive, or thermo-sensitive biomaterials for achieving lysosomal escape. [8][9][10][11][12] Apart from achieving proficient antigen delivery, the immunogenicity and adjuvant potential of nanovaccine are of paramount importance. 13 The cGAS-STING pathway emerges as a focal point in the design of nanovaccines.…”