Among various carrier materials for drug delivery, silica has been found to be significant for loading and sustained release of the drug. In the present study, the antibiotic gentamicin was incorporated in various amounts on to a silica matrix, using a sol-gel subcritical drying route. Crack free silica rods with a length of 1-1.5 cm, diameter of 0.5 cm and density of 1.35 g/cm(3) incorporated with gentamicin were obtained. The incorporation of gentamicin into the silica matrix was revealed by FTIR. The adsorption-desorption isotherms and pore size distribution were studied in detail. The drug elution patterns were analysed and show a biphasic mode of release. After the initial burst release, a constant release pattern is observed. A release value above the minimum inhibitory concentration (MIC) is always maintained. The amount of drug released is higher than that of many other bioactive ceramic materials. An attempt has been made to correlate the functional properties with the porosity features. (C) 2012 Elsevier Ltd. All rights reserved.