Synthesis of Magnetic Composite of Poly (Butylene Succinate) and Magnetite for the Controlled Release of Meloxicam

Controlled drug release systems can offer active agents into living organisms in a programmed manner. These release systems present several advantages. As the first one, they keep constant drug levels in the body, implying a lower drug content to produce the same effect as conventional systems. Besides that, they can preserve the drugs avoiding their destruction by the body. Finally, they can reduce the frequency of administration of the active agent, increasing patient comfort, and treatment efficacy [7]. Among them, responsive controlled release systems represent a particular category because they release the drug only when receiving a stimulus which can be internal, from the body (such as temperature, pH, or enzymatic action) or external like a magnetic or electric field, ultrasound, and near-infrared light. The last ones are named on-off delivery systems, and they are especially advantageous because the drug can be released just at the desired moment [8]. Magnetic nanoparticles (MNPs), especially the ones made of iron oxides, have excellent chemical stability, precise control over composition and structure and hence high efficiency in medical applications. However, MNPs have shallow zeta potential which is responsible for poor electrostatic repulsions and consequently a strong tendency to agglomerate [9]. This process can occur by flocculation (small aggregates) or coagulation (denser aggregates). Therefore, for clinical use, these particles should be covered with biocompatible material to maintain colloidal stability but conserving their magnetic properties. Polymers are the most used materials to prepare magnetic nanocomposites which are more interesting than pure NPMs for biomedical applications [9].