A composite magnetic nanoparticle drug delivery system pro­vides targeted controlled release chemotherapies for cancer­ous tumors and inflammatory diseases. The magnetic nano­particle includes a biocompatible and biodegradable polymer, a magnetic nanoparticle, the biological targeting agent human serum albumin, and a therapeutic pharmaceuti­cal composition. The composite nanoparticles are prepared by oil-in-oil emulsion/solvent evaporation and high shear mixing. An externally applied magnetic field draws the mag­netic nanoparticles to affected areas. The biological targeting agent draws the nanoparticles into the affected tissues. Poly­mer degradation provides controlled time release delivery of the pharmaceutical agent.