Drug delivery systems are the technology of controlling the spread of therapeutic agents. These systems make it possible to deliver the drug to the target tissue at a specific time so that the performance of the drug is optimal. Nanoparticles as drug carriers have the ability to deliver a variety of drugs to different parts of the body at the right time. In order to improve the loading and release efficiency of diclofenac, polymeric nanocomposites based on polyvinyl alcohol and chitosan as biodegradable polymers and FeOOH nanoparticles were synthesized and optimized, and its use as a pharmaceutical structure in controlling drug release was assessed. For this purpose, solutions with a pH similar to the physiological fluid of the human body were prepared in the laboratory and the drug was evaluated in vitro. We also used analyzes such as SEM, XRD and FTIR to characterize the synthesized nanostructures.