Abstract

A RATIONAL APPROACH TO OCULAR DRUG DELIVERY SYSTEMS: A OVERVIEW

Abstract

In the earlier period, drug delivery to the eye has been limited to topical application, redistribution into the eye following systemic administration or directs intraocular/per ocular injections. These novel systems offer manifold advantages over conventional systems as they increase the efficiency of drug delivery by improving the release profile and also reduce drug toxicity. Ocular drug delivery has remained as one of the most taxing task for pharmaceutical scientists. The unique structure of the eye restricts the entry of drug molecules at the required site of action. Innovatory novel therapy for treatment of ocular diseases has emerged due to the recent advances in drug delivery approaches and material sciences. The eye is a sensory and sensitive organ which is located on the surface of the body, is easily injured and infected according to the location of diseases, ocular disorders are grouped as periocular diseases and intraocular diseases. This review article briefly covers classification of ocular drug delivery systems and general outline with examples of various conventional and recent past time formulations for ophthalmic drug delivery. It also provides the limitations of conventional delivery with a view to find modern approaches like vesicular systems, nano technology, stem cell therapy as well as gene therapy, oligonucleotide and aptamer therapy, protein and peptide delivery, ribozyme therapy for treatment of various ocular diseases. The advanced drug delivery devices such as ocular insert, SODI, collagen shields, mini disc, liposomes, microspheres, nanoparticles and prodrugs, in spite of their advantages demonstrated by extensive investigations and clinical tests, have not gained a wide acceptance by ophthalmologists

Keywords: Physiology of eye, Ocular drug delivery, Ocular disorders, Advanced drug delivery etc.