Topical administration is the greatest alternative for ocular medicines since it
activates rapidly, doesn't cause systemic toxicity, and requires fewer doses than
systemic use. The inner workings of the eye must be reached by drugs applied
topically, and trans corneal penetration is assumed to be the primary route for drug
absorption. Corneal absorption happens significantly more slowly than
elimination. The specific objective of therapeutic system design is to attain the
optimal drug concentration at the active site for the appropriate duration of time.
The main obstacle to long-term ocular treatment is the capacity to maintain a
therapeutic dosage of medication at the site of action. The ocular absorption mode
of elimination is significantly slower. For many years, scientists have been
interested in the problem of effective topical administration. Their challenging goal
is to ensure proper ocular penetration and extend the drug's residence period.
Nanotechnology based carriers to ensnare both lipophilic and hydrophilic
medicines, improve ocular permeability, prolong residence duration, stabilize
pharmaceuticals and in vivo characterization techniques aid in the prediction of the
generated nanocarriers' results. Clarifying the architecture of the eye, different
ocular disorders, and barriers to ocular delivery are the goals of this review.