In this work, we obtained a mesoporous silica-calcium phosphate composite (MSi-CaP) in the form of spherical granules (pellets) loaded with cefazolin as a model antibiotic. First, the MSi-CaP composite was manufactured in the powder form via the sol-gel method using a soft template. The cefazolin was loaded into the MSi-CaP using the immersion method. The pellets were composed of MSi-CaP powders (both placebo and cefazolin-loaded) and excipients, such as microcrystalline cellulose and ethyl cellulose. The pellets were obtained in the laboratory scale using the wet-granulation, extrusion and spheronization method. The pellets proved satisfactory mechanical properties which allowed for further investigations (the drug release studies and the mineralization potential assay) without a risk of pellets cracking. The complete drug release from the pellets was observed after 12 h. The burst release of cefazolin from the pellets was reduced by 3 when compared to the burst release of cefazolin-loaded MSi-CaP powders (90 and 30% after 15 min of release studies, respectively). The pellets showed the mineralization potential in vitro, confirmed by the SEM-EDX and FTIR methods. After 60 days of the mineralization potential assay in the simulated body fluid, the examinations revealed that the whole surface of pellets was covered with the carbonated hydroxyapatite in accordance with the desired morphology.