Formulation and in vivo Evaluation of Acyclovir Loaded Chitosan Nanoparticles for Ocular Delivery

Abstract

The present study was aimed to formulate and evaluate chitosan nanoparticles containing acyclovir as potential ophthalmic drug delivery system. The topical application of acyclovir as eye ointment remains a concern for effective management of various ocular viral diseases owing to poor ocular drug bioavailability. The acyclovir loaded chitosan nanoparticles were prepared by ionic gelation of chitosan. Differential scanning calorimetry and fourier transform infra red spectroscopy measurements were carried out on the prepared nanoparticles, pure acyclovir and chitosan polymer. Fifteen different formulations were prepared and evaluated for particle size, Zeta potential, scanning electron microscopy, entrapment and loading capacity and in-vitro drug release profile. All the prepared formulations resulted in nano size in 377.9 to 720.6 nm and displayed spherical shape with zeta potential of +33.2 to +42.8 mV. The encapsulation efficiency and loading capacity were 70.7% - 90.9% and 25% - 50.8% respectively. The acyclovir loaded chitosan nanoparticles displayed crystallinity than acyclovir. The in-vitro release profile of acyclovir from the nanoparticles showed a sustained release of the drug over a prolonged period of 24 hours and fit best with Higuchi model with zero order and non- Fickian diffusion was superior phenomenon. The in vivo results reveal that ocular viral infections can be inhibited by the nanoparticles more significantly than the drug in conventional dosage forms. No appreciable difference was observed during 90 days in which nanoparticles were stored at various temperatures. Thus the results suggest that acyclovir loaded chitosan nanoparticle suspension appears promising for effective management of ocular viral infections.