Functionalized silica matrices for controlled delivery of cephalexine

ELENA I. BASALDELLA; M. SOLEDAD LEGNOVERDE; T. LOPEZ GOERNE; E. ORTIZ ISLAS

Conferencia; XVI International Zeolite Conference; 2010

Samples of SBA-15 grafted with acidic or amino groups were used as matrices for study the controlled delivery of cephalexine (CPX). CPX was impregnated on sulphonic-functionalized SBA-15 and amino-functionalized SBA-15. The matrices were characterized by SEM, TGA, FTIR and N2 adsorption, before and after impregnation, and the corresponding “in vitro” drug delivery tests were done. SEM micrographs show the packed cylinders usual to SBA-15 materials and the N2 adsorption-desorption isotherms correspond to IV type in nature. The preservation of the drug structure was confirmed by FTIR spectroscopy. The amount of drug loaded was evaluated by thermogravimetric analysis (TGA). Delivery profiles exhibit two steps, beginning with a fast delivery over the five first hours, followed by a slower desorption during the next 30h. The release rate is strongly influenced by the nature of the anchored groups, the slower delivery rate and delivery percentage being obtained when the amino-groups were attached.