Encapsulation study of citalopram and risperidone into nanostructured silica SBA-15 for in vitro release evaluation

Abstract

Ordered mesoporous silica, SBA-15, presents non-toxic nature; high pore volume and high surface area; thermal, hydrothermal and mechanical stabilities. These features may enable its use as a carrier for commonly prescribed drugs in psychiatric practice: citalopram (CIT) and risperidone (RIS). Thermogravimetry/derivative thermogravimetry (TG/DTG) and ultraviolet and visible absorption spectrophotometry (UV-Vis) were used to determine drug quantity into/onto ECIT (CIT encapsulated into SBA-15), ERIS (RIS encapsulated into SBA-15), MCIT (mixture of CIT with SBA-15) and MRIS (mixture of RIS with SBA-15). All materials were characterized through: TG/DTG, differential scanning calorimetry, elemental analysis, Fourier transform infrared absorption spectrophotometry and nitrogen adsorption-desorption. A general solvent-based method for loading these psychoactive drugs into non-functionalized SBA-15 showed to retard their liberation in simulated gastric and intestinal media when compared to physical mixtures performance. It is expected that the functionalization of this nanostructured silica may increasingly extend the dissolution of CIT and RIS after encapsulation process, leading to application in controlled release systems.