β-Galactosidase entrapment in silica gel matrices for a more effective treatment of lactose intolerance

In this work we present a preliminary study directed to the realization of a new pharmaceutical formulation for the treatment of lactose intolerance. The main aim of the work is to increase the stability of β-galactosidase in order to prolong its activity in the course of time, thus improving its performance as dietary supplement in the digestion of lactose. We describe a reliable and effective procedure for the immobilization of β-galactosidase in a three-dimensional silica network. A one-step approach was optimized by using the sol-gel method to obtain homogeneous and stable β-galactosidase/ silica gel composites; the textural properties of the porous surface were characterized by N2 physisorption analyses. The activity of β-galactosidase was evaluated in vitro in the hydrolysis of o-nitrophenyl-β-d-galactopyranoside (used instead of lactose) at pH 7.4 and 37°C, thus reproducing the conditions of the human intestine. © 2011 Elsevier B.V. All rights reserved.