An overview on ocular drug delivery system

Ocular medication delivery is the main issue facing pharmacologists and formulation scientists today. The easiest
and most widely used kind of treatment is a topical eye drop. Route of drug administration, particularly when treating
disorders of the anterior region. Various precorneal, dynamic, and static ocular barriers prevent medication delivery
to the targeted ocular tissues. Additionally, target tissues do not retain therapeutic medication levels for an extended
period of time. The ocular preparations consist of sterile, buffered, isotonic solutions. They are employed for quick
action. They are unable to hold on for an extended period. The fundamental problem with traditional ocular dose
forms is that they cannot keep a therapeutic level. Ophthalmic preparations must be devoid of irritants and their
physiological properties must not interfere with the eye's normal functioning or cause blurred vision of any kind. The
development of innovative, secure, and patient-compliant medication formulations and drug delivery
devices/techniques, which may overcome these obstacles and sustain drug levels in tissues, has increased over the
past two decades in the field of ocular drug delivery research. Among the various nanoparticles currently available,
lipid-based nanosystems have demonstrated increased efficiency and feasibility in topical formulations, making them
an important target for ongoing and thorough research in both preclinical and clinical practice. There are numerous
new drug delivery systems available for use in the eye. The current review aims to summarize the existing traditional
formulations for ocular distribution and their developments, followed by the most recent innovations in formulations
based on nanotechnology. Problems associated with traditional ophthalmic dosage forms may be alleviated by the
new drug delivery system. Also highlighted are recent advancements in various ocular drug delivery techniques using
in situ gels, implants, contact lenses, and micro needles