Mesoporous silica–based tablets to improve oral delivery of carbamazepine

Epilepsy affects around 50 million people worldwide, requiring long-term antiepileptic drug (AED) therapy. Carbamazepine, a widely used AED, effectively manages seizures and neuropathic pain. However, its poor water solubility limits bioavailability, necessitating higher doses that increase the risk of side effects. To address this, we developed carbamazepine-loaded mesoporous silica microparticles (SYLOID®) to enhance solubility and drug release. Carbamazepine was incorporated at 20–100% w/w (drug-to-carrier) theoretical loading ratio, achieving actual drug load values of 84–97%. Fourier-transform infrared spectroscopy (FTIR) confirmed drug incorporation, which was attributed to solvent viscosity and polarity, improving loading efficiency. Interactions between carbamazepine and SYLOID® silanol groups weakened molecular bonds and enhanced drug entrapment. Fluorescence-based 3D imaging and scanning electron microscopy (SEM) revealed crystalline formations on the silica surface, suggesting partial recrystallisation. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) confirmed the amorphous dispersion of the drug, a key factor in solubility enhancement. Mesoporous silica-based tablets achieved a cumulative in vitro release of 98.25 ± 3.28% after 6 h, outperforming unformulated carbamazepine (67.12 ± 4.11%) and commercial formulations such as Tegretol® (81.87 ± 6.49%) and Crescent Pharma's Carbamazepine (83.12 ± 0.68%). These findings highlight mesoporous silica microparticles as a promising approach to enhance carbamazepine solubility and bioavailability, potentially reducing side effects and improving therapeutic outcomes.