Novel drug delivery systems for glaucoma

Abstract

Reduction of intraocular pressure (IOP) by pharmaceutical or surgical means has long been the standard treatment for glaucoma. A number of excellent drugs are available that are effective in reducing IOP. These drugs are typically applied as eye drops. However, patient adherence can be poor, thus reducing the clinical efficacy of the drugs. Several novel delivery systems designed to address the issue of adherence and to ensure consistent reduction of IOP are currently under development. These delivery systems include contact lensesreleasing glaucoma medications, injectables such as biodegradable micro-and nanoparticles, and surgically implanted systems. These new technologies are aimed at increasing clinical efficacy by offering multiple delivery options and are capable of managing IOP for several months. There is also a desire to have complementary neuroprotective approaches for those who continue to show progression, despite IOP reduction. Many potential neuroprotective agents are not suitable for traditional oral or drop formulations. Their potential is dependent on developing suitable delivery systems that can provide the drugs in a sustained, local manner to the retina and optic nerve. Drug delivery systems have the potential to improve patient adherence, reduce side effects, increase efficacy, and ultimately, preserve sight for glaucoma patients. In this review, we discuss benefits and limitations of the current systems of delivery and application, as well as those on the horizon.

Nanosponge-Mediated Drug Delivery Lowers Intraocular Pressure

“…50,51,62,63 Additionally, a significant portion of drug (~80%) may be absorbed by blood vessels in the conjunctiva, passing into systemic circulation to cause adverse off-target effects. 64 Targeting tissues in the posterior globe, like RGCs, proves even more difficult as drugs must penetrate the vitreous and inner limiting membrane of the retina. 52 Due to these challenges, more efficient drug delivery systems are being developed for ocular tissues that include ocular inserts, lipid-based nanocarriers, nanoparticles, and punctum inserts.…”

Development of a novel injectable drug delivery system for subconjunctival glaucoma treatment

“…In medical literature, different approaches have been described utilizing topical, implantable, and injectable LDD systems [11]. Topical ocular systems administer drugs from the outside of the eye, while implantable and injectable systems release drugs within the eye.…”

Assessment of alkoxylphenacyl-based polycarbonates as a potential platform for controlled delivery of a model anti-glaucoma drug

“…dorzolamide hydrochloride) (2). These medications are typically administered as ophthalmic solutions.…”