Optimization to development of chitosan decorated polycaprolactone nanoparticles for improved ocular delivery of dorzolamide: In vitro, ex vivo and toxicity assessments.

The present research work was designed to develop dorzolamide-loaded chitosan-coated polycaprolactone nanoparticles (DRZ-CS-PCL-NPs) for improved ocular delivery. The nanoparticles were prepared by single-step emulsification technique and optimized using the three-factor three-level Box-Behnken design. The optimized DRZ-CS-PCL-NPs prepared with the composition of polycaprolactone (60 mg), chitosan (0.6%) and polyvinyl alcohol (1.5%). The particle size, polydispersity index, zeta potential and encapsulation efficiency of optimized DRZ-CS-PCL-NPs were found to be 192.38 ± 6.42 nm, 0.18 ± 0.04, +5.21 ± 1.24 mV, and 72.48 ± 5.62%, respectively. The dependent and independent response variables showed excellent correlation and signifying the rationality of the optimized DRZ-CS-PCL-NPs. The DRZ release from CS-PCL-NPs showed biphasic behaviour with initial burst release for 2 h after that sustained-release up to 12 h of study. The corneal flux experiment showed many fold enhancement in permeation across goat cornea. DRZ-CS-PCL-NPs exhibited 3.7 fold higher mucoadhesive strength compared to the control. Furthermore, the histopathological assessment and HET-CAM study revealed that the DRZ-CS-PCL-NPs were non-irritant and safe for ocular administration. Therefore, from the present study, it can be concluded that the optimized DRZ-CS-PCL-NPs are safe and have the potential for successful ocular delivery and improved therapeutic efficacy.