Calorimetric study of mesoporous SBA-15 modified for controlled valproic acid delivery

Sba-15 ordered mesoporous silica functionalized with (3-aminopropyl) triethoxysilane (aptes) was used as the carrier for anticonvulsant drug 2-propylpentanoic acid (valproic acid). the surface of sba-15 containing free silanol groups was modified with 3-aminopropyltriethoxysilane via postsynthetic reaction. functionalization of the carrier with basic aminopropyl groups resulted in an ionic interaction with acidic valproic acid. the samples of carriers and carrier-drug complexes were characterized by elemental analysis,n2 adsorption,ftir,and uv spectroscopy. the adsorption of valproic acid on modified mesoporous matrix was proportional to the amount of introduced aminopropyl groups. a thermodynamic study with isothermal titration calorimetry (itc) was made to characterize the modification and encapsulation of sba-15 with aptes and valproic acid,respectively. the maximum content of deposited drug in modified sba-15 was close to 30 wt.%. tests performed in acidic solution (ph 2.0) showed the best pharmaceutical availability. © 2013 liliana giraldo and juan carlos moreno-piraján.