ASSOCIATION OF NETILMICIN SULFATE TO POLY(ALKYLCYANOACRYLATE) NANOPARTICLES - FACTORS INFLUENCING PARTICLE DELIVERY BEHAVIOR

The entrapment of Netilmicin sulphate (NTS) in polyalkylcyanoacrylate nanoparticles could be of therapeutic interest particularly in the treatment of infection that localise in the macrophages. In fact, aminoglycosides are excluded from macrophages and therefore represent an ineffective therapy for the treatment of typhoid fever, despite the excellent in vitro activity. In this case the colloidal delivery system ensures the NTS targeting to the macrophages. In this paper it is shown that the various formulation conditions are capable of influencing: trapping capacity, particle size, molecular weight distribution. The nanoparticle preparation was carried out using three different methods in the presence of Tween 80 and Pluronic F68, as non-ionic surfactant. The incorporation method consisting in adding the drug to the polymerisation medium led to very low values of NTS entrapment; in addition, formation of instable suspension was obtained increasing the NTS concentration over 5 mg/ml. The other two methods consisting in the absorption of the drug in the polymeric network of the nanoparticles showed higher NTS entrapment values. The presence of the drug in the polymerisation medium influenced both particle size and polymer chain molecular weight, providing an increase in both values. These results indicate that arranging preparation conditions, it is possible to obtain a nanoparticle delivery device presenting the most suitable behaviour as a function of the therapeutic aim and administration route.