Amoxicillin-loaded polyethylcyanoacrylate nanoparticles: Influence of PEG coating on the particle size, drug release rate and phagocytic uptake

Polyethyleneglycol (PEG)-coated polyethylcyanoacrylate (PECA) nanoparticles loaded with amoxicillin were prepared and the influence of the PEG coating on the particle size, zeta potential, drug release rate and phagocytic upt ake by murine macrophages was studied. Experimental results show that this colloidal drug delivery system could be useful for intravenous or oral admi nistration. The profile of amoxicillin release from PECA nanoparticles syst em was studied under various conditions similar to those of some corporeal fluids. In all these experiments, amoxicillin release in the free form was studied by HPLC analysis. Experimental results showed that at pH 7.4 drug r elease rises when molecular weight of PEG added to polymerization medium in creases; in human plasma on the contrary drug release is reduced as molecul ar weight of PEG rises. Phagocytosis was evaluated by incubating amoxicilli n-loaded PECA nanoparticles with murine macrophages and determining the amo unt of phagocytized nanoparticles by dosing the amoxicillin present inside the macrophages. The results of this study showed significative differences between nanoparticles prepared in the presence or in the absence of PEG an d demonstrated that the PEG coating reduces the macrophages uptake. These r esults suggest that nanoparticles prepared in the presence of PEG are steal th carriers, which could be an injectable colloidal system able to avoid MP S recognition after intravenous injection. Experimental data of drug releas e at pH 1.1 and in the presence of urease, taking into account the mucoadhe sive properties of polyalkylcyanoacrylate nanoparticles and the activity of the amoxicillin versus Helicobacter pylori, suggest moreover that the coll oidal drug delivery system obtained in our laboratory could be useful for t he treatment of diseases caused by H. pylori by peroral administration. (C) 2001 Elsevier Science Ltd. All rights reserved.