Mesoporous silicate/alginate composites as a carrier for amitriptyline hydrochloride and in vitro release

The objective of this research is to prepare mesoporous silica (M41) based nanomaterials and encapsulate in the solid polymeric matrix for controlled drug release application. Amitriptyline (AT)-loaded M41/sodium alginate (AL) composite microparticles were prepared by the ion exchanged gelation techniques. Composite microparticles were characterized by FT-IR spectroscopy; surface area analysis and scanning electron microscopy. Here we propose mesoporous silica (M41) for loading of hydrophilic drug, amitriptyline (AT) and further constructed drug loaded M41 into a pH-responsive alginate microparticles. The resulting drug loaded composites microparticles was characterized by powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR), particle size and zeta potential analyzer. Drug loading was confirmed by the decrease of specific surface area and pore volume in the drug loaded composites as well microparticles. The morphology of drug loaded hybrid nanomaterials and composite micro spherical particles were evaluated by scanning and transmission electron microscopy (SEM and TEM, respectively) measurements. The AT release from microspheres composites was pH dependent, and the release rate was much lesser in gastric pH than that in intestinal pH media. Thus, the biocompatible composite spherical particles hold the substantial potential to be further developed as effective and safe drug-delivery carriers. Drug release kinetics (in vitro in simulated gastric and intestinal fluids) showed that both of them were affected by the properties of materials. The release profile of AT from composites was best fitted in Higuchi kinetic model while the Korsmeyer-Peppas model suggested a non fickian diffusion release mechanism. Such formulations show potential as an efficient controlled drug delivery system.