Novel nonporous membranes were prepared by impregnating brushite and niobium pentoxide (NbO) into a gelatin/alginate matrix. The physicochemical properties, morphology, and mechanical properties of the prepared membranes were characterized using X-ray diffractometer, FTIR spectroscopy, scanning electron microscopy, transmission electron microscopy, and universal testing machine, respectively. Swelling ability of the prepared membranes was determined in distilled water. The surfaces of the membranes were characterized by means of FTIR spectroscopy and scanning electron microscopy coupled with energy dispersive x-ray spectroscopy after submersion in simulated body fluid up to 15 days. Moreover, the calcium and phosphorus ion concentrations in the simulated body fluid were measured using an UV spectrophotometer. The in vitro drug release and the release mechanism of a model antibiotic, namely, ciprofloxacin (CFX), were tested in phosphate-buffered saline for 15 days. The antibacterial activities of the CFX-loaded membranes were tested against known microorganisms. The physicochemical properties, morphology, mechanical properties, and swelling ability of the prepared membranes were found to be dependent on the presence of NbO allowing control of their properties. For example, the NbO-loaded membranes exhibited a higher in vitro bioactivity and slower drug release compared to those of NbO-free membranes. The CFX-loaded membranes also exhibited an excellent inhibition zones against the selected microorganisms. Overall, the prepared membranes have been found to be very promising for use in bone substitute applications.