Vol. 1, Issue 12 (2013)

Author(s):
K. P. Sampath Kumar, Debjit Bhowmik, G.Harish, S.Duraivel , B. Pragathi kumar

Abstract:
Ocular drug delivery is one of the most challenging tasks faced by Pharmaceutical researchers. Major barriers in ocular medication are the ability to maintain a therapeutic level of the drug at the site of action for a prolonged duration. The ophthalmic preparations are available as sterile, buffered, isotonic solution. Several types of dosage forms are applied as the delivery system for the ocular delivery of drugs. The most prescribed dosage form is the eye drop solution as drops are easier to administer. Suspensions, gelled systems, ointment are also used for prolonged therapeutic action. Characteristics of ophthalmic preparations should be non-irritating to the ocular tissue. homogenous i.e., particles uniformly dispersed, smooth & free from lumps or agglomerates. Relatively non-greasy. Should not cause blurred vision. Should not cause intolerable foreign body sensation. Sterile and adequately preserved. Physically & chemically stable. Efficacious. New ocular drug delivery systems: Using eye drops to administer drugs needs frequent application. Prolonged drug release can be achieved using ophthalmic inserts, solid devices placed in the eye, but the inserts must then be removed when they are no longer needed. Ocuserts are the new drug delivery systems which are designed in such a way that they release the drug at predetermined and predictable rates thus eliminating the frequent administration of the drug. The systems generally include controlled, delayed and or sustained release bioerodible implantable elements having multiple layers of different materials and/or different concentrations of materials. The elements generally include an inner layer, or core, including a therapeutic agent, and one or more outer layers made of polymeric materials, for example substantially pure polymeric materials. In the area of topical ocular administration, important efforts concern the design and the conception of new ophthalmic drug delivery systems able to prolong the residence time.