Improved solubility of celecoxib by inclusion in SBA-15 mesoporous silica: Drug loading in different solvents and release

Abstract

In this study, celecoxib (CLX), a highly hydrophobic nonsteroidal anti-inflammatory drug with relatively low bioavailability, was used as a model drug to determine loading in different solvents and release properties from silica particles. Hydrothermal synthesis method was used to synthesize SBA-15 particles, which were functionalized by post-synthesis grafting method with (3-Aminopropyl) triethoxysilane (APTES). Additionally, boron doped SBA-15 samples were prepared to generate borosilicate samples. After functionalization, drug loading was carried out in three different solvents: ethanol, methanol and hexane and their effect on drug loading and release properties were examined. Particle morphology and solvent effect on drug loading capacity of silica particles, as well as the effect of pH on drug release were analyzed. For this purpose, SBA-15 particles were characterized by using X-ray Diffraction (XRD), Small-Angle X-ray Spectrometry (SAXS), N2 adsorption - desorption, Fourier Transform Infra-red Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), Ultra-Violet Spectrometry (UV-VIS) and Thermogravimetric Analysis (TGA).Herein we demonstrate a highly improved release rate of CLX by using SBA-15 silica particles as drug carriers compared to the commercial drug, Celebrex. We have observed slow release from SBA-15-A (APTES functionalized SBA-15) particles, while there was burst release from SBA-15-B (boron doped SBA-15) particles and all silica samples prepared in hexane. We also observed greater loss of viability with silica-CLX complexes compared to empty silica particles on colon cancer cell lines HCT-116 and HT-29 in vitro. Our results demonstrate the use of silica supports as potential drug delivery carriers for poorly water soluble drugs.