Preparation of epirubicin-loaded poly(butyl cyanoacrylate) colloidal particles by polymerization in a mixed organic–aqueous solvent system

This article considers the preparation of poly(butyl cyanoacrylate) colloidal drug carriers loaded with the anticancer drug epirubicin by emulsion polymerization in a mixed (acetone/water) solvent system. The use of acetone as a co-solvent allowed better dispersion of the monomer in the polymerization medium and lead to the formation of more uniform nanoparticles. The epirubicin-loaded nanoparticles were prepared in acidic medium containing citric acid and different colloidal stabilizers (dextran 40, poloxamer 188). The obtained nanoparticles were characterized for morphology, size distribution, zeta-potential, drug loading efficiency, drug content, drug release rate and molecular mass distribution. It was found that the nanoparticles prepared in the presence of dextran 40 had the highest drug content, loading efficiency and colloidal stability upon storage at 4 °C as a colloidal dispersion at pH 5.5. The drug loading efficiency was decreasing, while the drug content was increasing with augmentation of the initial drug concentration. The average particle size (~250 nm) did not depend strongly on the drug concentration and was within the ranges suitable for passive tumor targeting. The zeta-potential of drug-loaded nanoparticles was slightly positive in phosphate-buffered saline (pH 7.4) in contrast to the negative zeta-potential of the respective drug-free particles. The molecular mass of polymer in the case of drug-loaded nanoparticles was larger than in the case of drug-free nanoparticles. It is expected that these results should be useful for further successful development of nanoparticle-formulated anthracyclines.