Preparation of Hollow Mesoporous Silica-Based Carriers for Loading and Release of Fenofibrate

Hollow mesoporous silica-based materials are ideal drug carriers applied in controlled drug delivery systems due to their unique hollow core and tunable shell composition. Two types of hollow mesoporous materials, hollow mesoporous silica nanoparticles (HMSNs) and hollow periodic mesoporous organosilicas (HPMOs), were synthesized and applied as drug carriers to regulate insoluble drug release. Fenofibrate (FNB) was used as a model drug to study the effect of framework difference for HMSNs and HPMOs materials on the drug loading and release processes. FNB/HPMOs had a higher drug loading (35.39%) than FNB/HMSNs (30.22%) because of hydrophobic bridging C₂H₄ groups within the mesoporous skeleton. HMSNs showed fast release behavior, resulting from their hydrophilic surface with a large number of silanol groups favorable for dissolution media diffusion and drug dissolution. HPMOs showed sustained release behavior, attributed to their hydrophobic surface which possessed stronger hydrophobic-hydrophobic van der Waals attraction to drug molecules. The drug release of HMSNs and HPMOs in different dissolution media followed the first order kinetic model with decreased release rate vs. time. Regulation of the organic-inorganic skeleton structure of the mesoporous materials could change their surface properties especially hydrophilicity or hydrophobicity, furtherly controlling the loading capacity and release behavior of the loaded drugs.