Traditionally used eye drop formulations lacked good bioavailability and had low patient compliance, hence most investigations in this field emphasize on the duration of action and enhancement of corneal absorption.
Recent developments in ophthalmic drug delivery systems include use of gelling polymers, prodrugs, microspheres, nanoparticles, liposomes and hydrophilic ocular inserts. Protein and peptide delivery, posterior drug delivery and non-aqueous vehicles are new areas of interest in ophthalmic drug delivery. The Ophthalmic Drug Delivery Systems (ODDS) are desired to improve efficacy, minimization of toxicity, sustained effect or modified drug release. Cyclodextrin cyclic oligosaccharides are the newer carriers in ODDS which have proved to be useful for controlled release by forming a complex which is known to show rapid and quantitative drug release.
Other areas of research are polymeric gels, colloidal systems, nano particles and collagen shields to develop a preparation which not only prolongs the contact time of the vehicle at the ocular surface, but at the same time slows down the elimination of the drug. Combination of drug delivery systems can be considered for improving results and the therapeutic response of non-efficacious systems.
Ophthalmic laser delivery systems is a new advancement in this field which uses PASCAL (PAtterned SCAnning Laser) Photocoagulator designed to treat ocular diseases using a single shot or predetermined pattern array. Drugs to be administered via this route should have optimum viscosity, pH, isotonicity and the formulations available should be in suspensions, ointments, gels, drops and in solution form. For an ideal delivery of the drug in ODDS it should be able to pass through corneal membranes and match the isotonicity of the eye. This Online PowerPoint presentation will emphasize on advantages, disadvantages, mechanisms and recent advancements in the Ophthalmic Drug Delivery Systems.