A Review on Newer Ocular Drug Delivery Systems with an Emphasis on Glaucoma

Abstract

Glaucoma is an irreversible condition resulting from the increase in intraocular pressure (IOP); which leads to permanent loss of vision with the destruction of retinal ganglion cells (RGCs). The IOP elevations are controlled in normal by the physiological flow of aqueous humour. A population with age above 40 is more susceptible to glaucoma. Other factors like gender, genetics, race etc. plays major roles in the development of the disease. Current treatment methods available for the disease includes drugs come under the classes of beta receptor blockers, carbonic anhydrase inhibitors, cholinergic agonists, prostaglandins etc. N-methyl-D-aspartate (NMDA) antagonists, inducible nitric oxide synthase (iNOS) inhibition, cytoskeletal agents, Rho-kinase inhibitors etc are few novel targets sites which are in research focus for the treatment of the disease. Developments in nanomedicine are also being evaluated for their potential in treating the growing glaucomatous population. Nanosystems are suggested to avoid the difficulties in tackling the various ocular barriers to a limit, help to decrease the instillation frequency of topical medication and can provide drug delivery in a sustained or controlled manner. This review focuses on the current and emerging treatment methods for glaucoma along with some of the nanoformulations for ocular drug delivery.

Identifying and addressing common contributors to nonadherence with ophthalmic medical therapy

“…The bimatoprost SR (sustained release) implant can be administered in the office setting and can improve or eliminate nonadherence by lowering IOP for up to 6 months [188], although because of corneal safety concerns is indicated for one-time use only [189]. Multiple other novel SRDD platforms for glaucoma management are in various stages of development [178,179 ▪ ,180,190 ▪ ].…”

“…Historical, current, and future-sustained release drug delivery (SRDD) platforms can improve adherence by obviating adherence issues associated with topical instillation of glaucoma [178,179 ▪ ,180], anti-inflammatory [181,182], and allergic conjunctivitis [183] medications, and by reducing the dosing frequency of intravitreal therapies [184,185]. Further, because these SRDD platforms are formulated without preservatives, they also resolve issues related to OSD side effects commonly associated with topical therapies.…”