CHITOSAN NANOPARTICLES - THE DRUG DELIVERY SYSTEM TO THE ANTERIOR SEGMENT OF THE EYE

Abstract

The effectiveness of drug penetration into the inner tissues of the eye is signi cantly limited by the barrier effect of the cornea and by the washing out of a drug with tear uid. To increase the bioavailability of the drug, it was proposed to include the drug in chitosan particles formed by two types of chitosan - 5 kDa chitosan and 72 kDa glycol-chitosan. Chitosan particles with incorporated angiotensin-converting enzyme inhibitor enalaprilat, capable to reduce intraocular pressure, were characterized by dynamic light scattering and scanning electron microscopy. Particles formed by 5 kDa chitosan had an average hydrodynamic diameter of 85-125 nm and a positive ζ-potential of +21±3 mV, while particles formed by 72 kDa glycol-chitosan were 440-480 nm by size and had ζ-potential of +10±2 mV. The percentage of inclusion of enalaprilat in chitosan particles was 25% and 40%, respectively. In vivo experiments have shown that the inclusion of the drug in chitosan particles increased the retention time of enalaprilat in the lacrimal uid of rabbits.