Occular Drug Delivery System – A Review

The unique Anatomy of the eye makes it a highly protected organ and unique structure restricts entry of the drug into the target site of action. Designing an effective therapy for ocular diseases has been considered as a difficult task. Major barriers in eye medication are the ability to maintain a therapeutic level of the drug at the site of action. Therapeutic drug levels are not maintained for a longer duration in target tissues. Limitations of the traditional route of administration have challenged scientists to find an alternative mode of administration like periocular routes. The ophthalmic formulations are available as buffered, isotonic, sterile solution. A number of types of dosage forms are applied as the drug delivery system for the ocular delivery. The topical ocular drop is the most suitable and patient compliant route of drug administration, especially for the management of anterior segment diseases. Ideal ophthalmic drug formulation must be able to prolong the drug release and to remain in the area of the front of the eye for prolong period. It is necessary to optimize ophthalmic drug delivery; one way to do so is by adding polymers, development of in situ gel or using erodible or nonerodible insert orcolloidal suspension to extend the precorneal drug retention.