Influence of the structural and textural properties of ordered mesoporous materials and hierarchical zeolitic supports on the controlled release of methylprednisolone hemisuccinate

To alleviate the chronic inflammation, nasal obstruction, and loss of sense of smell that produces the rhinosinusitis disease, ordered mesoporous materials and hierarchical zeolites could be used for slow and sustained corticoid (methylprednisolone hemisuccinate conjugate) release. The correlations between the delivery performance of methylprednisolone hemisuccinate and the physicochemical properties of carriers' release systems, including pore mesostructure, texture and size, and surface chemistry, have been well established. Different two-dimensional (2-D) and three-dimensional (3-D) mesostructured materials (MCM-41, SBA-15, expanded SBA-15, FDU-12, and SBA-16) were employed. In addition, for the first time to the best of our knowledge, materials based on hierarchical zeolites with additional mesoporosity (h-ZSM-5 and h-BETA zeolites) were also tested. In particular, two materials (3-D cubic mesoporous silica SBA-16 and hierarchical Beta zeolite) have been probed to be potential candidates, exhibiting high drug adsorption capacities and slow drug release rates, which is the most favourable way of drug release in the particular rhinosinusitis application. Solid-state H-1-Si-29 HETCOR NMR analyses confirm the strong interactions of the drug with the surface of h-BETA and 3-D SBA-16 materials, via hydrogen bonding of carboxylic, ketone, and aliphatic moieties of the methylprednisolone hemisuccinate at surface silanol sites. Because of the remarkable release performance, it is expected that 3-D mesoporous silica SBA-16 and hierarchical Beta zeolite can be attractive candidates for current applications in nasal inflammation treatments. The drug release rate can be further retarded by decreasing the pH to around 4.6; at this point more attraction forces were detected as proved by zeta-potential measurements. Therefore, a slower delivery trend of methylprednisolone hemisuccinate has been observed for all the materials, which is more pronounced in the case of SBA-15 and SBA-16.