Fe3O4 nanoparticles with cubic phase were synthesized by a simple hydrothermal method at temperature about 100 degrees C. Then, Fe3O4-gelatin core-shell was prepared by a simple mixing procedure. For gradual drug release, aspirin and metoprolol were added to gelatin polymeric matrices to produce nano-capsules. Powdered nano-capsules containing magnetite, gelatin, and metoprolol or aspirin were prepared in the water as a green solvent. The samples were analyzed by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive Spectra analysis (EDX), Vibrating Sample Magnetometer (VSM), and Fourier Transform Infrared spectroscopy (FT-IR). The weight percent of various ingredients of the nano-capsule was also characterized by thermal gravimetric analysis (TGA). The release of metoprolol and aspirin were examined by UV-Vis spectroscopy in the human-blood-simulated (pH = 7.4) and human stomach-simulated (pH 1.9) environments at 37 degrees C, respectively. The results confirm suitable and gradual drug release in times 0.5 h-5 h. (C) 2019 Elsevier B.V. All rights reserved.