Mesoporous drug carrier systems for enhanced delivery rate of poorly water-soluble drug: nimodipine

Two mesoporous silica materials: MCM-41 and SBA-15 were applied as potential nanocarriers for poorly soluble drug-nimodipine. Drug incorporation was performed using modified adsorption from the solution method and loaded samples before and after washing procedure were studied. The physical properties were verified by: differential scanning calorimetry, X-ray powder diffraction, electron microscopies (SEM/TEM) and Fourier-transform infrared spectroscopy (FT-IR). FT-IR results for bulk nimodipine were interpreted on the basis of first principles calculations (DFT). As a result of encapsulation process, in both matrices nimodipine appeared simultaneously in two forms: crystalline and amorphous, but the first one turned out to be easily removable during washing procedure. The in vitro dissolution and release tests were performed with ultra pure water under supersaturating conditions. The release rate of the amorphous nimodipine from mesoporous silica materials was at least 70 times higher than dissolution rate of bulk drug, thus revealed a potential usefulness of such carrier in future pharmaceutical applications in terms of delivery of poorly soluble drugs.