• Kaushal Kumar
• Lakshyaveer singh

Eye is the most fantastic creation of God among all the sense organs in human body as it makes us aware of various objects all around us near and far. The eye is one of the most soft and most valuable of all the sense organs and is a challenging subject for topical administration of drug to the eye.(1) Topical application of drug in the form of eye drops in the eye is the well accepted route of administration for the treatment of various eye disease like conjunctiva, eye flu etc.(2) The eye as a portal for drug delivery is generally used for local therapy in order to avoid the risk of eye damage from high blood concentration of the drug which is not intended.(3) The field of ocular drug delivery system is one of the most interesting and challenging task usually faced by pharmaceutical scientist/researchers. This field has significantly improved over the past 10-20 years. The eye is very difficult to study from a drug delivery point of view. The anatomy physiology and biochemistry of the eye render this organ impervious to foreign substances. It is a challenge to the formulator to circumvent the protective barriers of the eye so that the drug reaches the bio-phase in sufficient concentration.(4) Ocular inserts have been developed in which the drug is delivered on the basis of diffusional mechanism. Such a solid dosage form delivers an ophthalmic drug at near constant rate, minimizing side effect by avoiding absorption peaks.(5) Physiological barriers to diffusion and productive absorption of topically applied drug exist in the pre-corneal and corneal space.(4) The novel system offers manifold advantages over conventional systems as it increases the efficiency of drug delivery by improving the release profile and also reduces drug toxicity. The rapid progress of the biosciences opens new possibilities to meet the need.(6) Most ocular treatments are done by topical administration of ophthalmically active drugs to the tissue around the ocular cavity. Several types of conventional dosage are applied as ocular drug delivery systems. Mostly prescribed conventional dosage forms are eye drop solutions, suspensions, and ointments. The conventional dosage forms are easy to administer but have a drawback that the content of medicine is immediately diluted in the tear film as soon as the conventional dosage form is administered into the cul-de-sac and rapidly drained away from the pre-corneal cavity by constant tear flow. Therefore, only a very small amount of the administered dose is absorbed in the target tissue because of reduced contact time of drug with target tissue and thus leads to poor ocular bioavailability.(7) The efficacy of any ophthalmic drug depends on the rate and extent to which the drug reaches aqueous humor and from there to the interior segment, the target tissue for providing expected therapeutic response. The zero order kinetics is a characteristic of sustained release type of delivery systems whereby the drug is held in a reservoir and is released in to the target tissue at a constant rate to provide constant concentration more than one doses are placed in such drug delivery systems which provides greatly improved compliance.(8) In case of ophthalmics the ocuserts are probably a good choice for this purpose since they increase the contact time with the conjuctival tissue.(9)

Review Article on Ocusert: A Novel Ophthalmic Drug Delivery System

"Review Article on Ocusert: A Novel Ophthalmic Drug Delivery System", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.1, Issue 3, page no.1221-1229, August-2014, Available :http://www.jetir.org/papers/JETIR1701589.pdf

"Review Article on Ocusert: A Novel Ophthalmic Drug Delivery System", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.1, Issue 3, page no. pp1221-1229, August-2014, Available at : http://www.jetir.org/papers/JETIR1701589.pdf